Table of Content

15 June 2024, Volume 45 Issue 06

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Fiber Materials

Preparation and properties of flame retardant modified polyethylene terephthalate by in-situ polymerization

WU Yuhang, WEI Jianfei, GU Weiwen, WANG Yuping, ZHANG Anying, WANG Rui

Journal of Textile Research. 2024, 45(06):  1-10.  doi:10.13475/j.fzxb.20221101501

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Objective Polyethylene terephthalate (PET) is widely used because of its excellent comprehensive properties, but PET has poor flame retardancy, which greatly limits its application. Traditional halogenated flame retardants have great impact on the environment during combustion and cause damage to people's eye sight. Hence, the research of new halogen-free flame retardants is imperative.

Method In this study, flame retardant polyester (DDP-gCDs-PET) was prepared with [(6-oxo-6H-dibenzo[c,e][1,2]oxahex-6-yl)methyl]succinic acid (DDP) and gelatin-based carbon dots (gCDs) as flame retardant by in-situ polymerization. To explore the flame retardant properties of PET, a study was conducted using limiting oxygen index (LOI), vertical combustion (UL-94) and cone calorimetry to assess the influence of gCDs with varying mass fractions.

Results gCDs are quasi-spherical in structure, with an average particle size of about 3.34 nm and good dispersion. FT-IR spectra demonstrated the presence of amino groups and carboxyl groups on the surface of gCDs. In addition, FT-IR spectra also demonstrated the successful introduction of gCDs, DDP into PET molecular chains. When DDP was 8% and gCDs were 1.0% (named DDP-1.0gCDs-PET), the glass transition temperature of DDP-1.0gCDs-PET was increased by 9.33% compared with that of pure PET. The temperature at which ester mass decreases by 5% of DDP-1.0gCDs-PET was increased by 10.32 ℃ compared to that of DDP-PET. Compared with PET, the peak heat release rate of DDP-1.0gCDs-PET was reduced by 39.77%, the total heat release was reduced by 25.00%, and the time to ignition was delayed by 25 s compared with that of PET. UL-94 and LOI studies show that DDP-1.0gCDs-PET had a LOI of up to 35%, and UL-94 was upgraded from V-2 to V-0. After the combustion of flame-retardant polyester, a continuous dense carbon layer was formed, which effectively hinders the spread of heat and gas and improves the flame retardant performance of the matrix. It is evident that DDP promoted the decomposition of the matrix and played the role of quenching free radicals when the matrix was burned. The addition of gCDs significantly reduced the concentration of CO₂ and CO in meteorological products and improved the quality of the carbon layer.

Conclusion Compared with pure PET, the flame retardant effect of DDP-gCDs-PET is significantly improved. The flame retardant mechanism of DPP and gCDs in PET system is understood. During the combustion process, gCDs absorb heat to form a heat conduction network, so that the heat diffuses rapidly and evenly in the matrix and delays the combustion of the matrix. DDP promotes decomposition of the matrix, while producing P=O to quench free radicals in the gas phase and dilute combustible groups in the gas. gCDs promote the retention of P in DDP in the carbon layer, forming a large number of dense and continuous high-quality carbon layers in the solidified phase to achieve the purpose of flame retardancy.

Properties of Bombyx mori silkworm silk obtained by forced reeling

LIU Shu, HOU Teng, ZHOU Lele, LI Xianglong, YANG Bin

Journal of Textile Research. 2024, 45(06):  11-15.  doi:10.13475/j.fzxb.20230204501

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Objective Bombyx mori silk fibers have an interesting and elaborate structure, but its mechanical properties are inferior to spider dragline silk. Therefore, it is of great significance to prepare Bombyx mori silk comparable to spider silk. Traditional silk processing technology, however, is difficult to enhance the performance of cocoon silk, and even damage its morphology and properties. In addition, artificial silk produced by a variety of spinning methods cannot fully replicate the properties of natural silk. Herein, we proposed a simple and effective strategy for preparing high-strength Bombyx mori silk, which not only retains the hierarchical structure of natural silk, but also advances its mechanical properties.

Method Inspired by spider silking, this work designed a conical forced reeling device that can consistently reel silk from the fifth instar silkworm at controlled reeling speed. In this study, the silkworms were forcibly reeled at 1-4 cm/s, resulting in the force-reeled silk fibers (FRSF-1, FRSF-2, FRSF-3, and FRSF-4). During forced reeling, the silk was fully stretched due to a recombination of the reeling force and the gravity of silkworm, which increased the orientation and crystallinity of FRSFs. Meanwhile, the cocoon silk fibers (CSFs) selected from the same batch were set as a control group. In addition, the characteristic of fiber morphology, fineness, and mechanical properties of all silk samples were performed.

Results The FRSFs have a smooth and uniform morphology, and a bow-shaped cross-section, which differs significantly from that of CSFs. Specifically, the transversal surface of FRSF-1 is almost a round triangular cross-section shaped like CSFs, and both the rounded triangular and bow-shaped cross-section appeared in FRSF-2. With the reeling speed further increasing, only bow-shaped transverse section can be found in FRSF-3 and FRSF-4. Furthermore, the mechanical properties including breaking elongation, stress, elastic modulus, and specific work of rupture of FRSFs are superior to that of CSFs. First of all, the stress of FRSFs increases with reeling speed increasing. More specifically, the stress of FRSF-1 is approximately 3.0 cN/dtex, which is similar to CSFs. In addition, the stress of the FRSF-2, FRSF-3, FRSF-4 increases to 3.20 cN/dtex, 3.34 cN/dtex, and 3.39 cN/dtex, respectively, with the increasing reeling speed. As for the elastic modulus, there is a clear phenomenon that the modulus of FRSFs is obviously larger than that of the CSFs, and increases with reeling speed. Accordingly, FRSF-1 has an elastic modulus of 93.10 cN/dtex, while the elastic modulus of CSFs is 76.90 cN/dtex. Besides, the specific work of rupture of FRSF-1, FRSF-2, FRSF-3, and FRSF-4 is as follows: 0.54 cN/dtex, 0.55 cN/dtex, 0.60 cN/dtex, and 0.62 cN/dtex. In contrast, the specific work of rupture of CFSs is 0.47 cN dtex. Moreover, the breaking elongation of FRSFs increases after force-reeling and shows a similar value with increasing reeling speed. As a result, the FRSF-4 exhibits integrated mechanical properties of superior breaking elongation (22.49%), excellent strength (3.39 cN/dtex), outstanding elastic modulus (95.76 cN/dtex), and supreme specific work of fracture (0.62 cN/dtex), which increases by 7%, 13.76%, 24.53%, and 31.91%, as compared to the average values of CSFs.

Conclusion In summary, the FRSFs with smooth morphology and improved mechanical properties was achieved by force-reeling. Notably, stress of the FRSFs increases as the reeling speed increases, and the elastic modulus of all these FRSFs is significantly higher than that of CSFs. This is due to the strong shear effect of the high-speed stretch that facilitates the orientation of the nanofibrils and improves the crystal structure of the nanocrystallites, thereby promoting the mechanical properties of FRSFs. The obtained FRSFs with satisfying elongation, high strength, superior modulus, and specific work of rupture broaden its application prospects in impact-resisting materials, biomedical materials, smart textiles and wearable electronics. Besides, the forced reeling processes and device need to be further modified to reduce the unstability of reeling tension and the fluctuation of fiber fineness.

Preparation of alginate nano montmorillonite modified fiber and its strengthening and toughening mechanisms

XU Jiahui, GUO Xiaoqing, WANG Wei, WANG Huaifang, ZHANG Chuanjie, GONG Zhaoqing

Journal of Textile Research. 2024, 45(06):  16-22.  doi:10.13475/j.fzxb.20221203601

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Objective The poor breaking strength and elongation at break are the main reasons that limit the wide applications of alginate fibers. Many approaches such as cross-linking, grafting and blending modifications have been developed to improve the physical and mechanical properties of alginate fibers. In this research, the reinforcing mechanisms of montmorillonite (MMT) were studied, and nano MMT was blended into sodium alginate(SA) solution to prepare modified calcium alginate(CA) fibers using wet spinning technique aiming to improve the mechanical properties of the alginate fibers.

Method Montmorillonite (MMT) suspension was blended with sodium SA aqueous solution to prepare the mixed spinning solution, before the SA/MMT fibers were prepared by wet spinning method using CaCl₂ solution as the coagulation bath. The microscopic morphologies and structural characteristics of the prepared fibers were characterized by using TEM, SEM, FT-IR, XRD and the mechanical properties and thermal stabilities of different fibers were tested by using single fiber tensile tester and thermogravimetric analyzer respectively to study the influences of different swelling time and contents of MMT on the corresponding fiber properties.

Results The layer distance of MMT was increased desirably after swelling for 120 h, and the swollen MMT was well dispersed in the spinning solution, which provided favorable conditions for SA to get into the macromolecular layers of MMT and eventually peel off the layers of MMT. The breaking strength of the CA/MMT fibers containing 0.1% MMT that swelled for 120 h was the best. This phenomenon is owing to the intercalation of SA into the uniformly dispersed MMT in the spinning solution, which is conducive to the combination of MMT and SA. Meanwhile, the result of the elongation at break was similar to that of the breaking strength of fibers, which could be explained that the formed hydrogen bonds among the hydroxyl groups on MMT and the ionized carboxyl groups on SA were conductive to overcoming stress concentration and increasing the crystallinity of SA molecules, and toughening the fibers. Compared with SA fibers,the addition of MMT made the fiber surface gully. Evidence showed that the MMT has been successfully loaded onto the CA fiber. The reason for this is that MMT in SA exists as a monolithic structure, which makes the viscosity of the spinning liquid increase and the entanglement point increase, affecting the SA macromolecular flow, and finally the spinning liquid bears a stronger tensile effect during spinning and increasing the friction during fiber formation. The hydrogen bond interaction between the hydroxyl group on the MMT and the ionized carboxyl group on the SA was confirmed, and the Si—O stretching vibration peak from MMT was also identified in the spectrum of SA/MMT fibers, indicating the successful blending of MMT and SA. The addition of MMT increased the crystallinity of CA fibers hence strengthening and toughening the fiber, and the test results corroborated with the above conclusions. The TG results indicated that the addition of MMT also improves the thermal stability of the fibers. The decomposition temperatures of the two types of fibers in the three stages were quite similar, but the carbon residue rate of CA fibers blended with MMT was higher than that of CA fiber, indicating that the addition of MMT can improve the thermal stability of the fibers.

Conclusion It is found feasible to use inorganic nanoclay for toughening the alginate fibers. Hydrogen bonding occurs between MMT and calcium alginate, increasing the intermolecular spacing. The addition of MMT did not obviously changes the chemical structure and crystalline structure of alginate fibers, making the thermal stability properties of alginate fibers improved to some extent.

Preparation and electrochemical properties of self-supporting polypyrrilone-based carbon fiber anode materials

XU Zhenkai, MA Ming, LIN Duojia, LIU Hang, ZHANG Jianfeng, XIA Xin

Journal of Textile Research. 2024, 45(06):  23-31.  doi:10.13475/j.fzxb.20230102001

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Objective As a flexible anode material, carbon nanofibers membrane is used in lithium-ion batteries, which has the advantages of high electron transfer rate and large electrolyte contact area. The search for novel carbon fibers precursors to prepare carbon fibers electrodes with good performance for flexible high-performance lithium-ion batteries calls for further research. Being an aromatic heterocyclic polymer, polypyrrilone (BBB) has a high carbon residue rate after carbonization, and is a preferred material as a precursor to new carbon fibers.

Method In order to investigate the electrochemical performance of polypyrrilone carbon fibers as self-supported anode materials, a mixture of polycarboxylic acid ammonium salt (PCAAS) and different mass fractions of poly(ethylene oxide) (PEO) was prepared into precursor nanofibers by electrostatic spinning technique. The precursor nanofibers were imidated and cyclized to form polypyrrilone fibers at 500 ℃, and then charred at 800 ℃ to form polypyrrilone carbon fibers (BCF), and BCF was assembled into lithium-ion batteries as an anode material, to investigate the morphology and electrochemical performance of BCF with different mass fractions of PEO, which were denoted as BCF-3, BCF-6, and BCF-9, respectively, based on the mass fraction of PEOs. BCF was used as an anode material for lithium-ion batteries, and the morphology and electrochemical properties of BCF were investigated under different mass fractions of PEO.

Results The surface of the precursor fibers is smooth, and the fiber diameter increases significantly when PEO concentration increased. It was found that the diameters of BCF-3, BCF-6 and BCF-9 are 31.2%, 24.2% and 3.2% lower than their precursors, respectively, and the decrease in fiber diameter was due to the pyrolysis of PEO as a sacrificial template. In addition, the fiber agglomeration of BCF-6 precursors decreased after carbonization. The FT-IR spectra and the XPS spectra showed that the residue of pyrrole N and imidazole N was present in all three samples, while the residual N in BCF-6 was the most. All three samples showed an amorphous carbon structure, and BCF-6 had the largest diffraction peak of 2θ=24°, and the carbon crystalline diameter corresponding to the carbon (002) surface and the width of the microcrystalline along the fiber radial direction were the largest, indicating that BCF-6 had a better carbon structure. Through thermogravimetric analysis, the carbon content of the three samples was estimated to be 94.9%, 97.5% and 96.4%, respectively. Cyclic voltammetry testing was essential for the study of electrode reaction processes and reversibility, and BCF was used as the anode material to assemble a button half-cell for the test. One oxidation peak appeared in the curves of all three samples, and the oxidation peak of BCF-6 was the most obvious. The high residual N in BCF-6 gave it a high electrochemical activity, and the higher carbon content of BCF-6 gave it a high specific capacitance. The Nyquist curve semicircle of BCF-6 depicted the smallest semicircle and the largest slope, indicating that it has the smallest charge transfer resistance and the fastest Li⁺ diffusion rate. The specific discharge capacity of the first cycle of the BCF-6 lithium-ion battery was 841.4 mA·h/g. After 100 cycles of charge-discharge cycles, the discharge specific capacity was 422.3 mA·h/g, and the coulombic efficiency was 98.71%. When the current density of rate test was 100, 200, 300, 400, 500 mA/g, the specific discharge capacity of BCF-6 was as high as 380.7 mA·h/g, which was 1.3% higher than the initial value. As a flexible self-supporting anode material, BCF was subject to the necessary flexibility tests. BCF-6 did not break and remained smooth and flat after folding and curling tests from 0° to 180°.

Conclusion The results show that the self-supporting structure of BCF is conducive to improving the structural stability and cycle stability, and BCF has residual N of pyrrole and imidazole after carbonization, which provides more active sites for Li⁺and improves the specific capacity of BCF. When the PEO concentration is 6%, the specific discharge capacity of the first cycle of the BCF-6 lithium-ion battery is 841.4 mA·h/g, and after 100 cycles, there is still a discharge specific capacity of 422.3 mA·h/g. In the rate performance test, when the current density returns to 0.1 A/g again, the specific capacity of BCF-6 discharge is 1.3% higher than the specific capacity of the first turn, showing excellent rate performance. BCF not only meets the demand for flexible energy storage, but also offers stable electrochemical properties. Its flexible self-supporting skeleton and high electronic conductivity loading substrate can effectively improve the mass specific capacity of anode materials, while reducing the problem of lithium dendrite growth. The selection of synthetic monomers for BCF can be further optimised by adopting tetramine and dianhydride monomers containing flexible groups in the monomers, in order to reduce the rigidity of the polymer chain segments and thus make BCF more flexible. In view of the excellent electrochemical properties and certain flexibility of BCF anode materials, their application in the field of wearable energy storage can be further studied.

Preparation and properties of low infrared emissivity temperature-controlled thermal infrared camouflage materials

SHI Jilei, CHEN Tingbin, FU Shaohai, ZHANG Liping

Journal of Textile Research. 2024, 45(06):  32-38.  doi:10.13475/j.fzxb.20230204401

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Objective Infrared (IR) stealth is essential in modern military. With the rapid development of infrared detection technology, effectively hiding targets and rendering them invisible to thermal infrared detectors have been great challenges. Infrared stealth effect is affected by both temperature and infrared emissivity, but most of the previous studies focused on a single factor, which limits the effectiveness of the products. In order to achieve better infrared stealth effect, a composite fiber membrane material was prepared with low infrared emissivity on the outer surface and temperature control function inside.

Method The continuous electrospinning method was used to prepare the composite fiber membrane with the effect of controlling temperature and moderating infrared emissivity. By controlling the mass ratio of polyethylene glycol(PEG1000 and PEG4000) and the amount of nano-iron particles, the fiber membrane with different phase change temperature and infrared emissivity was obtained. The mass ratio between PEG4000 and PEG1000 was 2∶1, 3∶2,1∶1 and 2∶3, and nano-iron particles accounted for 10%, 20%, and 30% of the PAN quality, respectively. The apparent morphology, chemical and phase structure, thermal properties and infrared emissivity of the composite fiber membranes were studied. The infrared stealth properties of composites were investigated.

Results The surface of pure PAN fibers is smooth and the diameter distribution is uniform. The phase change fibers doped with polyethylene glycol became rough and wrinkled, and some fibers exhibited a fine groove-like morphology, which is, however, regular without showing polymer intorface separation. The composite fiber was well formed and showed certain dimensional stability. The infrared spectrum demonstrated that PAN(polyacrylonitrile) and PEG(Polyethylene glycol) have good binding and compatibility, which is consistent with the results of SEM. With the different mass ratios of PEG4000 and PEG1000, the phase transition temperature was between 31.5-40 ℃, with a regulation range of about 10 ℃. The phase change enthalpy and phase change temperature of fiber membrane PCM1(the mass ratio between PEG4000 and PEG1000 is 2∶1) changed less more than 2 % after 40 thermal cycles, indicating good energy storage stability. The temperature control effect of phase change fiber membranes with different thicknesses was analyzed. The phase change fiber membrane PCM1 with 0.9 mm and 1.2 mm thicknesses was placed on a 55 ℃ hot stage. When the surface temperature of PCM1 reached about 40 ℃, the heating rate was significantly slowed down, which was consistent with its phase change endothermic temperature. The temperature rise rate of 0.9 mm and 1.2 mm thick PCM1 fiber membranes became very slow after 6 min, and the actual temperature difference with the surface of the hot stage was 7 ℃ and 12 ℃, respectively.This is because the relatively thick fiber membrane means more phase change materials, which can absorb more heat and form better temperature control effect. The infrared emissivity of PAN, 0.1Fe/PCM1,0.2Fe/PCM1 and 0.3Fe/PCM1(nano-iron accounts for 0%, 10%, 20% and 30% of the PAN quality, respectively) were 0.9,0.82,0.69 and 0.75, respectively. The infrared emissivity of the fiber membrane decreased after the addition of nano-iron, and reached the lowest when the doping amount was 20 %. In the absence of sunlight, it is equivalent to the environment of grass or rock (infrared emissivity 0.65-0.75). By placing 0.2Fe/PCM1 on the hot stage, it can be seen from the infrared thermal imaging that it is similar to the radiation color of the environment and has infrared stealth effect.

Conclusion Through multi-component design and structural construction, a composite material with low infrared emissivity on the outer surface and internal insulation and temperature control functions has been prepared. The synergistic effect achieves the infrared camouflage function of the material, and to some extent overcomes the limitation of achieving infrared camouflage from a single aspect. It is hoped that it can provide a new way of thinking for the research of infrared stealth materials.

Preparation and properties of waste cotton/cellulose nanofiber self-reinforcing composite paper

LIU Xin, WANG Chan, DOU Hao, MENG Jiaguang, CHEN Li, FAN Wei

Journal of Textile Research. 2024, 45(06):  39-45.  doi:10.13475/j.fzxb.20230204001

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Objective Cotton waste accounts for 35%-40% of the global textiles waste of more than 100 million tons annually, with a low recycling rate of less than 30%. In particular, the fallen cotton fibers less than 7 mm during the mechanical opening process are not used because they are too short to be processed into fiber nets or other forms of textiles. It is imperative for such short cotton fibers with or without dyes to be recycled to avoid environmental pollution and recycle these high-quality cellulose resources.

Method Aiming at the problems that the waste cotton short fibers produced after mechanical opening and recycling have poor mechanical properties and are difficult to reuse, the part recovered waste cotton short fibers were oxidized in 2,2,6,6-tetramethylpiperidine-1-oxide radical (TEMPO)/NaBr/NaClO system to prepare cellulose nanofiber (CNF). CNF suspension with different concentrations and recycled waste cotton short fibers were thoroughly mixed to prepare all cellulose pulp. Finally, the full cellulose fiber self-reinforced composite paper (CCP) was formed by wet-laid forming and hot-pressing technology. The CCP was prepared from waste denim to maximize the use of very short cotton fibers. The morphology, mechanical properties, and reinforcement mechanism of CPP were characterized and analyzed.

Results CNF was successfully prepared by the TEMPO oxidation method, and the obtained CNF had a regular long strips with the length of about 0.8-1.2 μm and the diameter of about 10-35 nm. The FI-TR showed that there were absorption peaks corresponding to —COOH or its derivatives at 1 755 cm^-1 and 1 670 cm^-1. This indicated that the cotton short fiber was successfully oxidized by the TEMPO/NaBr/NaClO oxidation system to introduce carboxyl groups and transferred into CNF. In the aspect of CCP morphology, the surface pores of CCP decreased significantly with the increase of CNF concentration, leading to dense structure of CCP, and the pores on the surface and cross section of CCP with 5% CNF were filled. This indicates that CNF as a reinforcing agent in the pulp can bind closely to the pulp fibers. It effectively fills the pores between the cellulose fibers, making the paper form a dense structure. Moreover, the mechanical properties of CCP kept increasing with the increase of CNF concentration. The tensile strength of CCP with 0% CNF was 11.20 MPa, and that of CCP with 5% CNF was 4.72 MPa. It was also found that the maximum increase of CCP with 5% CNF in bursting strength and in tearing strength was 2.5 times and 1.8 times higher than those of 0% CNF. In addition, the XPS results showed that the relative content of C2 (C—OH) increased continuously from 37.03% for 1% CNF to 72.03% for 5% CNF and the relative content of O1s1 (C—OH…O) increased from 52.44% for 1% CNF to 72.29% for CCP with 5% CNF. This indicates that the hydrogen bonding content of CCP increases with with higher CNF concentration.

Conclusion The TEMPO/NaBr/NaClO oxidation system was utilized to introduce carboxyl groups on the cellulose surface, and CNF was successfully prepared. The addition of CNF effectively improved the mechanical properties of CCP. The CNF formed an extensive cross-linked network with the recycled cotton short fibers through hydrogen bonding, which facilitated the self-reinforcing effect of cellulose. Since CCP is composed of all-cellulose material, it has good sustainability and can be applied in green packaging. This work can be further explored in the future to develop special papers (e.g., banknote paper and other security papers), different sensors as components of smart packaging.

Textile Engineering

Structural control and spinning technology of highly wrapped core-spun yarn with thin sheath

LI Wenya, ZHOU Jian, LIAO Tanqian, DONG Zhenzhen

Journal of Textile Research. 2024, 45(06):  46-52.  doi:10.13475/j.fzxb.20230701401

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Objective The wrapped effect has always been the core indicator in the market to judge the quality of the core spun yarns. In the market, the number of the wrapped fiber is always more than 80% to achieve the core filament being wrapped. The difficulty in achieving good wrapping effect lies in controlling the center position of the core wire. It is of great theoretical significance and application value to achieve high wrapping effect of yarn based on low outer fiber ratio and stable control of yarn structure, thereby improving the multi-component advantage of core yarn.

Method To achieve high yarn wrapping effect and structural stability, this research proposed a solution by installing a filament control device to adjust the spinning process and parameters. Low-elastic polyester filament with a linear density of 7.78 tex as the core yarn, cotton roving with different quantities of as wrapping fibers were used to spin cotton/polyester core-spun yarn by ring spinning. The critical wrapping ratio of core-spun yarn was explored. The relationship between the structure of core-spun yarn and the wrapping rate was analyzed. The concept of yarn section eccentricity was introduced, and the structure stability of yarn was characterized by combining yarn coverage rate and longitudinal appearance morphology.

Results The relative position of the polyester filament and cotton roving was controlled by the installed a filament positioning device. The component ratios of polyester filament and cotton roving in 8 sets of core-spun yarns are 75/25, 70/30, 65/35, 60/40, 55/45, 53/47, 52/48, 50/50; The density of core-spun yarn is 31.8, 25.5, 21.6, 19, 17.4, 16.5, 16, and 15.7 tex, respectively. 50 images were collected for each group of yarn with 100 times magnification, and the obtained image was binary-processed by Ostu algorithm to calculate the yarn coating rate. Compared with other binary processing methods, the Ostu algorithm had the smallest error probability and higher accuracy. When the component ratio of cotton roving was 53%, the coverage rate of core-spun yarns remained at 87.5%. When the component ratio of cotton roving was less than 53%, the coverage rate of core-spun yarns was lower than 85% and a large area of core polyester was exposed. It is concluded that critical coverage ratio of core-spun yarn was when the component ratios of polyester filament and cotton roving was 53/47. The average variation range of eccentricity of core yarn section under different polyester-cotton ratios was 8.8%~11.2%. The characterization of section eccentricity, yarn coverage, and longitudinal appearance morphology verified the effectiveness of the spinning process adopted in this laboratory.

Conclusion The experiment provides data support and characterization for the discussion of the critical coverage rate during spinning cotton/polyester core-spun yarn by ring spinning. The computer image processing method for calculating the core-spun yarn coverage rate was obtained, which is convenient to operate and accurate. In addition, the factors affecting the stability of core yarn structure are analyzed from the perspective of theory and spinning practice, and the stable control of core-sheath structure is achieved by adjusting the spinning process.

Design of quartz/fiber mat three-dimensional spacer fabrics and investigation of their thermal insulation properties

LI Jiugang, SHI Yufei, LIU Keshuai, LI Wenbin, KE Guizhen

Journal of Textile Research. 2024, 45(06):  53-58.  doi:10.13475/j.fzxb.20230203501

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Objective Quartz fibers and their fiber mats are known for their high temperature resistance, strength and insulation and are widely used in the aerospace industry. However, how to composite quartz fibers and their fiber mats to give them the integrity and washout resistance of aerospace materials. Therefore, we performed composite weaving using an integrated weaving method and investigated the thermal insulation properties of quartz/fiber mats three-dimensional spacer fabrics.This study aims to provide valuable insights into the weaving of quartz fibers and the overall structural thermal insulation properties of three-dimensional fabrics.

Method Quartz/fiber felt three-dimensional fabrics, quartz yarn and fiber felt with better thermal insulation properties using a one-piece knitting method for knitting, fabric thickness instrument to measure the quartz/fiber felt three-dimensional spacing fabrics, calculating the number of single-layer quartz fiber fabrics of equal thickness, placing the fabric on the top of the heating plate, the sensor to measure the temperature of the fabric's upper and lower surfaces, calculating the rate of retention of the thermal insulation.

Results According to the variation of the fabric thermal insulation performance, the thermal insulation performance of quartz/fiber mat 3-D spacer fabrics is much higher than that of quartz fiber fabrics of the same thickness. By comparing thermal insulation retention of ordinary quartz fiber fabrics with quartz/fiber mat 3-D fabrics. Quartz/fiber felt three-dimensional fabrics of thermal insulation performance is significantly better than the same thickness of ordinary quartz fiber fabrics, spacer fabrics of thermal insulation temperature retention rate of up to 300 ℃, the retention rate of 64.3% is ordinary quartz fabrics insulation effect of 4.14 times, so it shows that the quartz/fiber felt three-dimensional spacer fabrics can be better applied to the application of heat-insulating materials.

Conclusion The following conclusions were drawn from the experiments. The quartz/fiber mat three-dimensional spacer fabrics showed a linear decrease in insulation temperature retention of 64.3%, 64.2%, 60.7%, 58.4%, and 56.4% with the increase in temperature during the testing process, which was attributed to the fact that the quartz fiber mats were partially damaged to the fabric insulation structure after being heated to too high a temperature, resulting in a decrease in the heat insulation capacity. In the test of ordinary single-layer ordinary quartz fiber fabric, with the increase of temperature, its thermal insulation temperature retention rate is 15.4%, 15.5%, 15.9%, 17.2%, 18.6%, and quartz/fiber mats three-dimensional spacer fabrics thermal insulation performance in contrast to spacer fabrics for the ordinary quartz fabrics 4 times, thus verifying that quartz/fiber mats three-dimensional spacer fabrics thermal insulation performance is excellent.

Fabric drape profile simulation based on deformable mesh

CAO Jingzhe, TAO Chen, BAI Linlin

Journal of Textile Research. 2024, 45(06):  59-67.  doi:10.13475/j.fzxb.20230103501

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Objective In allusion to the stitch of constrained fabric simulation, this paper proposes a deformable mesh for reproducing the drape profile of fabric. Aiming to represent the dynamic process rather than static form of the fabric drape, the mesh model is featured with kinetic parameters and an evolution process to enable shape change over time.

Method In the mesh model, the constraints inside the fabric were built up through a constraint factor as well as an attenuation factor, and the contact between the fabric flexible body and the rigid plane was performed with a Touch-Counteract mechanism. The forces on the particles in the mesh, which were calculated with mesh deformation, were then used to generate the further displacement of the mesh. The evolution of the mesh was brought up by step-by-step iteration to introduce draping kinetics of the virtual fabric.

Results The drape profile of virtual fabric is achieved as the evolution processs meets its steady state. The drape coefficient is then worked out through identifying and quantifying the projection area of the mesh. The impact of the constraint factor and the attenuation factor on the drape coefficient are investigated, which has revealed the features and range of the model parameters capability. With lower attenuation factor (e=0.6), larger drape coefficient can be brought about while the range of the drape is narrow, and the drape is mainly affected by the attenuation factor and the effect from the constraint factor is relatively minor. When the attenuation factor grows (e=1.2 or e=2.4), smaller drape can be achieved while the range of the drape gets broader, and the constraint factor becomes more influential. When the attenuation factor goes up to 3.6 plus, the range of the drape turns to shrink, and the influence from the constraint factor recedes again. The upper limit of the range for the drape approximates 1.0 when the attenuation factor gets close to zero, and the lower limit of the range approaches 0 when the attenuation factor grows. Therefore, the theoretical range (0,1) of the drape coefficient gets fully covered with the mesh. Concerning the unevenness ripples, the reason for real fabric is discussed and reduced into the mechanical anisotropy. By emulating anisotropy through the differentiated constraint factors, the uneven appearance along the draping surface is manipulated and manifested. Finally, the precise of the model is boosted with respect to the mesh scale as well as the evolution algorithm, and a sensible mesh scale value 57 has been figured out for balancing between the simulation effect and the resource consumption. By employing the third-order Tylor expansion, the computational error is minished and the precision of the evolution algorithm is raised up to O(Δt⁴).

Conclusion It has turned out in the simulation experiments this mesh to be a simple, fast and precise model for expressing fabric draping. In the mesh model, the constraint factor and the attenuation factor together have been testified to be a compact approach to expressing the mutual effects between different parts of the real fabric. By recognizing and quantifying the projection area, the drape coefficient of the virtual fabric well meet the theoretic range of it. The drape coefficient has been found positively related to the constraint factor, and negatively related to the attenuation factor, and the latter has comparatively more impact on the drape coefficient. There are two kinds of precision involved in this model, i.e., the mesh precision and the algorithm precision. The former is determined by the mesh scale, and an appropriate scale has proved to be a trade-off between precision and efficiency considering the rapid growth of computational resource demand along the scale. While the algorithm precision can be improved significantly with the third-order Tylor expansion.

Digitization prediction of air permeability of weft knitted fabrics based on stitch model

ZHAO Yajie, CONG Honglian, DING Yuqin, DONG Zhijia

Journal of Textile Research. 2024, 45(06):  68-74.  doi:10.13475/j.fzxb.20221205101

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Objective Fabric stitch is an important factor affecting the air permeability of knitted fabrics. In order to correctly evaluate the air permeability of double-sided weft knitting fabric before the actual production, the double-sided fabric stitch model is constructed, and the digital expression of fabric porosity is made, so as to realize the prediction of fabric air permeability.

Method According to the Peirce weft knitting classical loop model, the unit stitch model is constructed for knitting structure including three basic loop forms: knitting stitch, tuck stitch, and miss. Then, based on the above three basic unit stitch models, the weave model of the fabric formed by weft knitting was constructed and digitized, the theoretical porosity was calculated, and the air permeability was measured by YG461E-III automatic air permeability meter in turn, and the relationship between the theoretical porosity and air permeability was obtained by linear fitting. Finally, two fabrics were selected to verify the rationality and applicability of the prediction system.

Results The unit stitch model was constructed for the 3 basic loop forms including knitting stitch, tuck stitch, and miss assuming that the loop form in the fabric in a completely ideal state. Setting the yarn diameter as d, the knitting stitch model, tuck stitch model, miss model of yarn vertical mapping area are achieved to be approximate to 16.34d², 11.63d², 4d². For weft knitted double-sided fabrics in a rib configuration, when the front and back loops that can tuck or not knockover at most once, the assembly of loop units forming the front and back of the fabric is shown. When the front and back loops that can tuck or not knockover two or more times, the loop cell assembly is shown. By dividing all the loop forms by the structural unit division method of the stitch of the fabric and the morphological approximation method, it can be concluded that the front surface of the fabric contains 9 kinds of (F₁-F₉) different lattice yarn morphological models, the reverse side of the fabric contains 21 different (B₁-B₂₁) lattice yarn configuration models. Through the digital transformation of the stitch model and the construction of porosity matrix, the calculation method of the theoretical porosity of the fabric is obtained. The design of three weft double-sided stitch with different structures, calculating the theoretical porosity using the same method, and the theoretical porosity of the fabrics formed by the three stitch was 25.34%, 33.63%, and 27.01%, respectively. Then, the air permeability of the three fabrics was measured. The theoretical porosity and air permeability were analyzed by linear regression. And a linear regression equation is obtained. Through theoretical calculation, the air permeability of the three fabrics are 790.5, 1 128.4, and 858.6 mm/s, which are less accurate than the actual measured air permeability (the error rate is within ± 6%). The comparison results of the theoretical calculation and actual measurement of the two fabrics selected finally are in line with the above deduced results.

Conclusion This paper predicts the air permeability of complex fabric based on the three basic unit stitch models of knitting stitch, tuck stitch, and miss. Through the stitch model construction and digital transformation of the stitch of the three designed fabrics, the theoretical porosity of the fabric is calculated, and according to the measured air permeability, the linear regression analysis of the theoretical porosity and air permeability was carried out, and the linear regression equation which can explain the relationship between the two factors was obtained. In addition, through the air permeability analysis of the two selected fabrics, the analysis results are consistent with the above-deduced results, indicating that the construction method of the stitch model and the theoretical deduction method of the relationship between porosity and air permeability are reasonable and applicable, which provides a new method for the air permeability prediction of knitted fabrics.

Digital modeling method for triangular braiding process

WANG Hui, ZHOU Wei, CHEN Yizhe, LONG Wanxin, WANG Jinhuo

Journal of Textile Research. 2024, 45(06):  75-81.  doi:10.13475/j.fzxb.20230300301

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Objective The carrier track for the traditional track-and-column three-dimensional (3-D) braiding is fixed, resulting in low flexibility. In quadrangular and hexagonal 3-D braiding machines, the area ratio of the yarn carrier to the braiding plate is relatively small, resulting in low utilization of the braiding plate area. The triangle braiding process has the highest chassis utilization rate and excellent mechanical properties, and makes it significant research topic. To further study the braiding technology and algorithm of the triangular 3-D braiding, it is necessary to digitally model the braiding components and movements and to establish geometrical models of meso-structure of fabrics, which can provide a guidance for the development of new braiding techniques.

Method In the triangular braiding process, the horn-gears and the switch-gears drove the carriers while they were alternately rotating, resulting in the yarns interlacement. Horn-gears, switches, and carriers were simulated to study the movement rules of carriers. The path of carriers and the height of the braiding node jointly determined the spatial topological structure of the fabric. The cubic B-spline curve was used to optimize the spatial paths of the yarns, and the Python script was written to drive CATIA to establish the meso-structure of preforms. Furthermore, the visual interface of the fabric structure was developed with PyQt5.

Results The machine bed of the triangular braiding device mainly consists of three-wing gears and yarn carriers. These gears were independently driven by stepper motors, thus providing high flexibility. The gears were divided into two groups: horn-gears and switch-gears, with rotation angles being multiples of 120° and not exceeding 360°. The movements of the horn-gears, switch-gears, and yarn carriers were progrmmed, relating the movement of ths yarn carriers to that of horn-gears. The movement of the yarn carrier was classified into two scenarios: tracking the motion of the horn-gear and tracking the motion of the switch-gear, and corresponding formulas for position exchange were derived for each case. The projected curve of the spatial trajectory of the yarn conforms to the proportion relationship with the yarn carrier's motion path. By adjusting the scaling factor, the yarn arrangement kept compact and without penetration. Combined with the lifting height, the 3-D coordinates of the yarn trajectory points were obtained. The obtained yarn trajectory was interpolated and fitted using cubic B-spline curves, driving CATIA to establish a detailed meso-structure. A fabric structure simulation software was developed with the PyQt5 library to interactively set braiding process parameters and the initial layout of horn-gears, output spatial trajectories of all yarns, and generate fabric geometric structures. When the rotation directions of horn-gears and switch-gears were the same and their angles were both 120°, the yarns would not able to intertwine, thus unable to form a prefabricated structure. When the rotation directions of horn-gears and switch-gears were opposite, and their angles were both 120°, the yarn projection trajectories would form triangles, with the three sets of trajectories interweaving, resulting in a uniform and compact prefabricated structure. The braiding experiments were conducted on the rectangular cross-section fabrics, demonstrating good consistency between the theoretical model and experimental specimens. This validates the accuracy of the process modeling method proposed in this paper.

Conclusion The triangular 3-D braiding process could make yarns interlace with each other to form a braiding compact fabrics. The proposed modeling algorithm could simulate the meso-structure of fabrics with different braiding angles, and the fabric model was consistent with the experimental fabric. The developed fabric simulation software could visually display fabric models under different parameter combinations. In the future, the multiple structures of braiding fabrics could be obtained based on the triangular 3-D braiding process, thereby providing guidance for studying their mechanical properties.

Effect of different sensory modalities on wetness perception of fabrics

TAN Yidan, ZHANG Zhaohua, LI Shihan

Journal of Textile Research. 2024, 45(06):  82-88.  doi:10.13475/j.fzxb.20230203901

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Objective Wetness perception is an important sensation to evaluate whether the human body is comfortable or not. In recent years, in order to clarify the factors affecting wetness perception, scholars have mostly analyzed from two aspects, temperature and mechanical stimulation, while ignoring the influence of sensory modality on wetness perception. Therefore, in order to clarify the relationship between sensory modality and wetness perception, this paper conducts wetness perception evaluation experiments by selecting fabrics with different properties based on dynamic contact between skin and fabric.

Method For the experiment, three fabrics with comparable thickness but distinct moisture transfer properties were selected: fabric 1^#, a 100% cotton sweatband with a weft flat knit construction, exhibiting excellent moisture-wicking properties; fabric 2^#, 100% Coolmax^®, featuring a double jacquard construction and a modified polyester with a radial 6-groove structure, renowned for its superior moisture transfer capability; Fabric 3^#, a polyester-ammonia blend sweatband with a weft flat knit construction, characterized by poor moisture-wicking performance. The samples were subjected to three levels of wetness: low (L), representing 20% of the saturated water content; medium (M), at 50% of the saturated water content; and high (H), reaching 80% of the saturated water content. Among them, the experimental fabric with the level of L was used as the standard stimulus. In a subjective evaluation experiment, 21 female participants with a mean age of approximately 22 years dynamically interacted with fabrics through touch under three sensory modalities (tactile unimodal, visual-tactile bimodal, and audio-visual-tactile trimodal), and the assessments of the perceived magnitude of wetness sensation were obtained.

Results According to three-way repeated measures ANOVA, there were no significant effect of sensory modality [F (2,40) =2.463,p =0.098]and fabric type [F (2,40) =2.989,p = 0.062]on wetness perception, while a significant effect of water content [F (1.217,24.335) =109.627,p <0.001]or interactions between fabric and water content[F (2.697,53.942) =4.276,p =0.011]was found. Bonferroni's post hoc analysis displayed significant difference between the two water contents (p <0.001), with the humidity levels increasing with increasing water content in the knitted fabrics. At low level of water content, there was no significant difference on wetness perception score among fabrics; at medium level of water content, the wetness perception score of fabric 3^# (polyester) was significantly lower than other fabrics; at high level of water content, the wetness perception score of fabric 2^# (Coolmax^®) was significantly lower than fabric 3^#, while no significant difference between other fabrics. The wetness perception scores in the different sensory modalities were as follows: tactile unimodal: (4.767 ± 0.070); visual-tactile bimodal: (4.730 ± 0.052); and audiovisual-tactile trimodality: (4.941 ± 0.053). The multisensory modalities (visual-haptic bimodal and audiovisual-tactile trimodality) of moisture discrimination were greater than the tactile unimodality. Furthermore, the moisture discrimination was greater at low level than at high level humidification capacity. In addition, applying multiple regression analysis, regression equations with sensory modality, water content, and fabric type as independent variables and moisture discrimination (d') as the dependent variable is established. The results show that water content had the highest influence weight, followed by fabric type, and finally sensory modality. Together, the three independent variables explained 34% of the total variance, which was statistically significant (p = 0.032).

Conclusion This article analyzes the effects of sensory (three levels), fabric (three levels) and water addition (three levels) on skin wetting. Studies have shown that fabric and water addition have an interactive effect on skin wetness, and wettability classes increase with increasing moisture content. The audiovisual-tactile trimodality was higher on wetness perception score compared to other modalities (tactile unimodality and visual-haptic bimodal), but not statistically difference. The multisensory modalities of wetness sensitivity were greater than the tactile unimodality. By evaluating the effect of sensory modality on skin wetness sensation, the theoretical basis of multisensory genesis was enriched. In addition, the study of the effect of different interaction methods on wetness sensation can provide a reference for the comfort design of human-computer interaction. It can also be applied to fields such as sports and medicine to improve the wetness sensation experience of clothing comfort.

Detection of fabric surface defects based on multi-metric-multi-model image voting

ZHU Lingyun, WANG Chenyu, ZHAO Yueying

Journal of Textile Research. 2024, 45(06):  89-97.  doi:10.13475/j.fzxb.20221201501

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Objective Fabric surface defects influence the textile output, quality, price, and other factors directly, and it is hence necessary to devise a method for detecting fabric surface defects quickly and accurately in automatic production lines. This research aims to establish a statistical algorithm to achieve rapid detection of fabric surface defects.

Method Partial defects on the fabric surface could destroy its periodic geometric and statistical characteristics. Based on this feature, a detection method combining with an improved RANSac, named multi-metric-multi-model image voting (MMIV), was proposed. The input image was firstly divided into sub-images of the same size, and the output value matrix of the sub-image multi-dimensional metric was calculated. They were different from the multi-dimensional measurement standard values of the flawless background calculated by the improved Zero-Slope-RANSac method, and the basic scores of each sub-image were obtained by voting. Then the comprehensive scores obtained under the 4 counting models(square of standard mean, Borda, Copeland, Maximin) were sorted, finally, the defect sub-image represented by the outer point was obtained at the output end according to the sequence and offset.

Result The tested subjects were the self-sampled fabric defect dataset. When the RANSac method parameter was set to 3 and threshold set to 2, the confidence was greater than 0.25 and the prediction accuracy of single-measure-single-model reached 89.3% on average. The prediction accuracy reached 95.6% when the gray mean measure and Borda ranking model were selected, which was the highest, while the square of standard mean model (SSM model) had the lowest accuracy. Accuracy under 4-measures-3-models showed the prediction of 2 565 grey fabric images with non-latticed texture, and that of 3 708 grey fabric images with latticed texture background. The confidences of the both tables were greater than 0.35, and the prediction accuracy of each model was compared with the values of RANSac parameter set from 1 to 3, and the threshold set from 1 to 4. The prediction accuracy of Borda, Copeland, and Maximin points of the last three counting models was better than that of the SSM method. The average prediction accuracy of the combined multi-metric-multi-model image voting reached 92.7%, demonstrating a significant detection effect. By means of comparing non-lattice and lattice, it can be seen that the optimization of the multi-metric-multi-model image voting strategy was not applicable to lattice texture for the time being. Under the condition that high detection accuracy can be guaranteed, the detection speed of ZS-RANSac with 200 iterations was more than 5 times that of 1 000 iterations, meanwhile, the detection time reached only 0.466 s, satisfying the real-time performance of pipeline work. Among the four prediction models, the SSM model was 10 times faster than the other three models, and the average time of the other three models were relatively close, reaching the fastest 0.135 s of the Copeland model. Considering accuracy and real-time performance, the Borda counting model demobnstrated the best results.

Conclusion It can be seen from the experimental results that, the proposed algorithm can detect defects on the fabric surface for periodic texture images quickly and accurately, and a new dichotomy labeled dataset for periodic texture grey fabric was created. The algorithm does not require a large amount of preliminary data for training, can overcome the problem of the lack of public datasets in the industry to a certain extent, and is suitable for real-time defect detection of solid color and striped background fabric. This technology is able to reduce the labor cost of the factory in the industrial entity under certain circumstances, and provides an idea to apply the software statistical prediction method to the research of image algorithms. Future work would focus on metric screening and model optimization in multi-metric-multi-model image voting(MMIV),as well as adaptive optimization of RANSac involved parameters, to further improve detection accuracy and average detection speed.

Dyeing and Finshing Engineering

Investigation on solubility of SCFX-AYRL dye in supercritical carbon dioxide

ZHAO Xiangyang, YAN Kai, LONG Jiajie

Journal of Textile Research. 2024, 45(06):  98-104.  doi:10.13475/j.fzxb.20230203001

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Objective In order to promote the commercial application of supercritical fluid of carbon dioxide (SCF-CO₂) coloration technology, the study of the solubility of various dyes in SCF-CO₂ plays an important role in the effective selection of dyes, the design of processes, and the improvement of process efficiency, particularly for a good color matching and hue control. Therefore, the purpose of this work is to investigate the solubility and its dissolving behaviors of a new Reactive Disperse Red SCFX-AYRL dye in SCF-CO₂, which could provide a basis for the applications of the special dye and the SCF-CO₂ technology in practice.

Method In order to investigate the solubility and the dissolving behavior of the special dye in SCF-CO₂, a self-developed solubility testing device involving a sampling unit was used. Moreover, a calibration curve between the dye concentrations and its corresponding absorbance was constructed by a standard addition method in acetone solution. Thus, different solubilities and its dissolving behavior of the dye at different conditions were determined via a sampling method from the testing device system after a dissolving equilibrium. Then the results were fitted by an empirical Chrastil equation, and the dissolution behavior was also predicted by this model.

Result The effects of treatment duration, temperature, pressure, and cosolvent system on the solubility of the dye in SCF-CO₂ were investigated. A series of visible absorption spectra and a calibration curve for the special dye in acetone solution were developed for the determination of the dye solubility in subsequent experiments. At a system pressure of 20 MPa and various temperature conditions, the solubility of the dye in SCF-CO₂ first increased and then approached equilibrium as the dissolution duration extended from 10 min to 60 min. A significantly shortened dissolution equilibrium time was also observed as the temperature increased from 80 ℃ to 130 ℃. When the system pressure was raised from 6 MPa to 24 MPa under a same dissolution temperature condition along with dissolution duration of 60 min, the solubility of the special dye in SCF-CO₂ demonstrated a rapid increase first, and then its increasing became slower. These results showed that the increases in dissolving duration, temperature, and pressure in an appropriate range helped to improve the dissolving behavior of the dye under those conditions in pure SCF-CO₂fluid. As the cosolvents, octadecylamine and methyl salicylate were added, the solubility of the SCFX-AYRL dye in SCF-CO₂ was rapidly enhanced firstly as the dissolving duration prolonged from 10 min to 60 min, and then it approached equilibrium or saturated state. When the system pressure was increased from 6 MPa to 24 MPa under the conditions containing cosolvents and the same temperature, the solubility of the SCFX-AYRL dye was seen to increase first and then also tended towards equilibrium. It was made clear that selecting appropriate cosolvents would significantly improve the solubility of the dye in supercritical carbon dioxide. For the SCFX-AYRL dye, the solubility data obtained under different temperatures, pressures, and cosolvent conditions were well fitted and correlated by the Chrastil empirical model. Moreover, these results further indicated that the Chrastil empirical model were effectively correlate and predict the solubility data of the SCFX-AYRL dye in pure SCF-CO₂ and SCF-CO₂/cosolvent system, and the correlation between experimental data and the Chrastil empirical model could be effectively improved by the addition of cosolvents.

Conclusion In pure SCF-CO₂ system, the dissolving of the special dye in SCF-CO₂ could reach an equilibrium within 30-60 min under the conditions of 20 MPa and system temperatures over 80-130 ℃, and the solubility of the special dye could be improved by increasing the fluid temperature and system pressure in an appropriate range, respectively. The addition of cosolvents could improve the dissolving behavior of the special dye and significantly improve their solubility and dissolving rate, as well as decrease the influences from the system temperature and pressure. In addition, the dissolving behaviors of the special dye in SCF-CO₂ and SCF-CO₂/cosolvents were well correlated and predicted by the Chrastil empirical model.

Construction of catalytic system by Fe^Ⅲ(tpy)Cl₃ complexes-activated periodate and its catalytic degradation mechanism for dyeing wastewater

WU Shouying, HUANG Qichao, ZHANG Kaifeng, ZHANG Linping, ZHONG Yi, XU Hong, MAO Zhiping

Journal of Textile Research. 2024, 45(06):  105-112.  doi:10.13475/j.fzxb.20230507301

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Objective The dyeing wastewater poses a threat to the ecological environment. Advanced oxidation processes (AOPs) exhibit excellent oxidation efficiency in wastewater treatment. The solid-state and stability of periodate (PI) make it obtained wide attention. As a result, PI-based AOPs are gradually gaining research and being tried for the treatment of dyeing wastewater. However, current transition metal-based activators for PI often require larger doses to obtain the desired effect, which undoubtedly increases the cost of wastewater treatment. Metal coordination complexes are applied similarly to biological enzymes, with trace and efficient application effects. This study aimed to construct a novel catalytic system by activating PI by Fe^Ⅲ(tpy)Cl₃ complex to investigate its application prospects in wastewater treatment and to elucidate the catalytic mechanism.

Method The catalytic degradation performance of the Fe^Ⅲ(tpy)Cl₃/PI system was tested using the dye Acid Red 1 (AR1) as the target pollutant. The effects of catalyst and oxidant dosage, pH, and temperature on the catalytic performance of this system were explored. Meanwhile, the catalytic mechanism of the system was investigated by capture and probe experiments. Moreover, the practical application prospects of the system were evaluated by testing the degradation efficiency of various organics and the resistance to inorganic salt ions.

Results The result showed that the Fe^Ⅲ(tpy)Cl₃ complexes have excellent activation effects on PI, which could remove 98% of AR1 within 15 min. More importantly, the performance of the Fe^Ⅲ(tpy)Cl₃/PI system is much higher than that of the previously reported Fe^Ⅲ(tpy)Cl₃/H₂O₂ system. Meanwhile, the test results show that the concentration of Fe^Ⅲ(tpy)Cl₃ and PI has a great influence on the performance of the Fe^Ⅲ(tpy)Cl₃/PI system. In detail, the degradation of AR1 in the Fe^Ⅲ(tpy)Cl₃/PI system is following the pseudo-first-order kinetic model, while the rate constant of AR1 degradation increase linearly with the increase of Fe^Ⅲ(tpy)Cl₃ and PI dose. Moreover, the results show that the catalytic performance of Fe^Ⅲ(tpy)Cl₃/PI system is almost independent of pH and could achieve efficient degradation of the dye over a wide pH range (3-9). Also, the increase in temperature could increase the catalytic activity of the Fe^Ⅲ(tpy)Cl₃/PI system and accelerate the degradation of AR1. In addition, the active species in this system were investigated using methanol, benzoquinone, and furfuryl alcohol as hydroxyl radical, superoxide radical, and singlet oxygen trapping agents, respectively, and PMSO as a probe for high-valent metal-oxo. The results of mechanism studies show that Fe^Ⅲ(tpy)Cl₃/PI system includes superoxide radicals, singlet oxygen, and high-valent metal-oxo, and these active species together promote the degradation of AR1. The removal rates of sulfamethoxazole, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and rhodamine B in the Fe^Ⅲ(tpy)Cl₃/PI system are 100%, 81%, 89%, and 89%, respectively, indicating that the Fe^Ⅲ(tpy)Cl₃/PI system is well suited for the removal of most organics. Inorganic salt ions are usually included in the actual organic wastewater. The results show that the catalytic system is not disturbed by common inorganic salt ions for the degradation of organic matter and has good prospects for practical application.

Conclusion Fe^Ⅲ(tpy)Cl₃ has excellent activation performance for PI, and the removal rate of AR1 is up to 98% within 15 min, which is much higher than the conventional Fe^Ⅲ(tpy)Cl₃/H₂O₂ system. Compared with other iron-based catalysts, Fe^Ⅲ(tpy)Cl₃ complexes are simple to prepare and require only minute doses to achieve efficient degradation of organic matter, which helps to reduce the economic cost of wastewater treatment. In addition, the system shows universality for the degradation of various organics, and the catalytic degradation process do not interfere with the solution pH and common inorganic salt ions, which makes this system excellent prospect for practical wastewater treatment applications. Overall, this study provides a novel PI activator and also provides an efficient method for dyeing wastewater treatment.

Preparation and application of durable aqueous organic-inorganic hybrid fluorine-free water-repellant finishing agents

MA Yiping, FAN Wuhou, HU Xiao, WANG Bin, LI Linhua, LIANG Juan, WU Jinchuan, LIAO Zhengke

Journal of Textile Research. 2024, 45(06):  113-119.  doi:10.13475/j.fzxb.20230506001

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Objective Fabrics with water-repellent finishing have been extensively favored by consumers as one of the most widely used functional fabrics, and hydrophobic coatings and their applications prospects attract interests from both the academic and industrial comunities. However, their application is hindered by some major bottlenecks, especially the poor durability. Therefore, a method for preparing hydrophobic coatings with excellent mechanical stability is urgently necessary.

Method To tackle the poor durability of water-repellent finishing fabrics, this study innovatively introduced low surface energy polysiloxane segments and long carbon chain hexadecyl at the same time. A novel durable water-based hybrid fluorine-free water-repellant finishing agents (NSW) were prepared by amino modification of silica sol emulsion to enhance the interfacial interaction between the organic and inorganic components. This modification corresponded to the long-chain alkyl silane modified sol emulsion and polysiloxane modified waterborne polyurethane emulsion respectively. The specific methods used were described below. A polysiloxane modified polyurethane prepolymer (SiWPU) was synthesized through the polyaddition reaction of polydimethylsiloxane (PDMS), polyethylene glycol (PEG), dimethylol propionic acid (DMPA) and isophorone diisocyanate (IPDI). A method of the long-chain alkyl silane and amino modified sol emulsion (Si-NPs) was provided through the hydrolysis polycondensation reaction of hexadecyl trimethoxysilane (HDTMS), silane coupling agent (KH-550) and tetraethyl silicate (TEOS). Si-NPs were added drop by drop in the emulsification process of Si-WPU, silica nanoparticles were adhered to the polyurethane chain segment taking advantage of the difference in the rate of isocyanate group react with amino and hydroxyl group, and isocyanate group exhibits a higher rate of reaction with amino compared with hydroxyl group.

Results The chemical composition of Si-NPs and NSW were investigated using Fourier transform infrared spectroscopy. The most stable emulsion was achieved when KH-550 mass fraction was 1.5% (Si-NPs-1.5 and NSW-1.5), and the stability analysis of Si-NPs and NSW-1.5 were demonstrated using particle size tester and Zeta potential analyzer. In addition, the research also focused on the hydrophobic effects of the amount of aminosilane coupling agent in the silica sol. Baking temperature on the property of finished polyester/cotton fabric was also discussed in detail, and the hydrophobic performance and the wash resistance on the surface of finished polyester/cotton fabric were also investigated. It was found that when the mass ratio of KH-550 was 1.5% and the baking temperature remained at 160 ℃, NSW formed a complete water-repellent membrane. Under the conditions of these application environment on the surface of treated fabric with water contact angle (WCA) of 131.8°, the WCA of the treated fabric dropped by only 2.8°after 20 rubbing cycles and exhibited good washability. The surface morphology of the treated polyester/cotton fabric before and after washing was observed in order to study the water wash resistance on the surface of finished polyester/cotton fabric more intuitively, and the results of SEM images showed that micro-nano rough structures existed on the surface of finished polyester/cotton fabric. Additionally, the repellent effect of the treated fabric on different liquids was also studied to demonstrate the above viewpoint.

Conclusion It is confirmed through the research that when the mass ratio of KH-550 is 1.5% and the baking temperature remains at 160 ℃, the surface of the finished fabric exhibits the best water resistance performance. In view of the poor durability of finishing agents, a method for preparing fully aqueous and organic-inorganic hybrid fluorine-free water-repellant finishing agents was identified, which is to combine the long-chain alkyl silane modified sol emulsion and polysiloxane modified waterborne polyurethane emulsion for the stable preparation of waterproofing agents.

Preparation and flame-retardant performance of coated polyamide 6 fabrics with biomass phytic acid modified polyurethane

CHENG Xianwei, LIU Yawen, GUAN Jinping, CHEN Rui

Journal of Textile Research. 2024, 45(06):  120-126.  doi:10.13475/j.fzxb.20230604501

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Objective Polyurethane (PU)-coated polyamide 6 (PA6) fabrics are widely used in various applications such as parachutes, luggage fabrics, tent covers, and other canopy materials. However, the PU-coated PA6 fabrics are highly flammable and cannot meet the fire-proof regulations. Besides, the generation of droplets during combustion can further increase the risk of fire. Therefore, it is essential to develop an environmentally friendly and efficient flame-retardant system to enhance the flame retardancy of PU-coated PA6 fabrics. Phytic acid (PA) is primarily sourced from plant seeds, roots, and stems, making it a valuable resource, the advantages of which include natural degradability, eco-friendliness, and high phosphorus content (28%). This study aims to investigate the effectiveness of biomass phytate salt in modifying water-based PU coatings to improve the flame retardancy and reduce the dripping behavior of coated PA6 fabrics.

Method Waterproof PA6 fabrics with grade 4 waterproof performance were developed to prevent permeation during the PU coating process. The phytate salt flame-retardant was prepared by combining PA and sodium phytate to a pH of 7.5 with a mass ratio of 5∶17. The phytate salt was then incorporated into the PU resin along with the capping polyisocyanate crosslinker 903. The resulting flame-retardant PU was applied to the PA6 fabrics using a laboratory small-scale scraper, and the coated PA6 fabrics were pre-dried at 110 ℃ for 3 min and baked at 150 ℃ for 3 min. The coating add-on to the fabrics was controlled to 50, 100, and 150 g/m² to achieve specific performance characteristics.

Results The flame retardancy, washing resistance, static water pressure resistance, thermal stability, and flame-retardant mechanism of coated PA6 fabrics were analyzed. The results suggested that the phytate salt was highly compatible with PU and did not significantly affect its film-forming performance. PA6 fabrics coated with phytate salt-modified PU exhibited the self-extinguishing properties during the vertical burning test without producing melting drips. The damaged length decreased from 30.0 cm to 12.4 cm, and the limiting oxygen index was increased to 29.0% from 20.8% of the pristine PA6 fabric. As a result, the coated PA6 fabrics met the B1 classification according to standard GB/T 17591. Even after 10 washing cycles, the coated PA6 fabrics retained their self-extinguishing properties, demonstrating good flame retardancy and washing resistance. The introduction of phytate salt-based PU coating had a significant impact on the thermal degradation of the PA6 fabric. The initial degradation temperature of the coated PA6 fabric shifted to lower temperatures, indicating that the phytate salt decomposed at a lower temperature and promoted the dehydration of the PA6 fabric, thereby accelerating its thermal degradation. When the coated PA6 fabrics were calcinated at varying temperatures, significant dimensional changes at the beginning were observed, and bubbles on the surface of the residue were formed. These observations could be attributed to the thermal degradation of the phytate salt, which caused the dehydration of the coated PA6 fabric. Additionally, the phosphorus content of the char residues of coated PA6 fabric showed a slight increase below 400 ℃, followed by a significant increase at higher temperatures. This behavior was linked to the thermal degradation of the PU-coated PA6 fabric, which released gases such as acetaldehyde, methane, and carbon monoxide after reaching 400 ℃. These findings were consistent with the thermogravimetric analysis, confirming that phosphorus primarily operated in the condensed phase during the combustion process.

Conclusion Phytate salt demonstrated the high flame-retardant efficiency for PA6 fabrics coated with PU. Even after undergoing 10 washing cycles, the coated PA6 fabrics were able to pass the vertical burning test and achieve a B1 classification. Analyses conducted on thermal and char residue revealed that the phytate salt system primarily improved flame retardancy through a solid-phase flame-retardant mechanism in these PU-coated PA6 fabrics. Overall, the modification of phytate salt into water-based PU coatings presents a promising and environmentally friendly solution for enhancing the fire safety of outdoor PA6 fabrics coated with PU and holds significant potential for commercial applications.

Preparation and performance of antibacterial polyester knitted fabric for automotive seats

LI Qianqian, GUO Xiaoling, CUI Wenhao, XU Yuzhen, WANG Linfeng

Journal of Textile Research. 2024, 45(06):  127-133.  doi:10.13475/j.fzxb.20230502401

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Objective Car seats are the most frequently touched parts by the human body during the use of the car, and human sweat and dirt can easily adhere to the car seat fabric. The interaction of the sweat and dirt can produce low fatty acids and some volatile compounds, which would emit foul odor, causing concerns to quality of life and human health. Therefore, it is necessary to develop antimicrobial car seat fabrics to improve the interior environment of automobiles.

Method With tetrabutyl titanate as titanium source, boric acid and urea as dopants, and polyester knitted fabric as substrate, polyester knitted fabric loaded with boron-nitrogen co-doped nano-titanium dioxide (B-N-TiO₂) antibacterial agent was prepared by rapid sol-gel method. The antibacterial properties of B-N-TiO₂/polyester knitted fabric specimens were analyzed by oscillation tests under solar light illumination using Escherichia coli and Staphylococcus aureus as the target strains. X-ray diffraction and UV-Vis diffuse reflection absorption spectroscopy were used to analyze the spectral properties of antibacterial agents. The breaking strength, the wear resistance, the water repellency, the color fastness against rubbing, and the pH value of polyester knitted fabric specimens before and after antibacterial finishing were tested.

Results By measuring the bacteriostatic rate of B-N-TiO₂ photocatalytic antibacterial agents with different boron doped amounts on E. coli, the optimal molar ratio of boric acid and tetrabutyl titanate was found to be 0.75∶1. The optimal impregnation loading process for B-N-TiO₂/polyester knitted fabrics was selected by orthogonal test optimization process under the conditions of 5 min impregnation loading time, baking temperature 120 ℃, and baking time 15 min. The antibacterial inhibition rates of B-N-TiO₂/polyester knitted fabric specimens prepared by the optimal process against Escherichia coli and Staphylococcus aureus were 98.4% and 94.4%, respectively, and the antibacterial rates after 20 washes were 91.8% and 91.3%, respectively. The microscopic morphology of the fabric before and after the loading of photocatalytic antibacterial agent was analyzed, and it was found that after finishing with antibacterial agent, a layer of smooth membrane was tightly coated on the surface of polyester fiber, and that after 20 washes, a large proportion of membrane was still tightly wrapped on the fiber surface. After loading the antibacterial agent, the breaking strength of the fabric was increased, the wear resistance was increased, and the water repellency level of the fabric was enhanced. The color fastness against rubbing was not changed. The pH value of the water extract of the antibacterial fabric was reduced, and the key properties were found in line with the requirements of relevant standards.

Conclusion B-N-TiO₂ photocatalytic antibacterial agents have excellent loading effect on polyester fabrics. After 20 times of washing, a very small part of the antibacterial agent membrane on the surface of fiber in the antibacterial fabric cracks and falls off under the impact of water flow and steel ball rubbing, but a large quantity of antibacterial agent membrane wrapped on the fiber surface, which further indicates that the antibacterial fabric has excellent durability and antibacterial properties. The result confirms that the durable antibacterial performance of the B-N-TiO₂/polyester knitted fabric exceeds AA level.

Metal-organic frameworks/polypropylene fiber-based composite for rapid degradation of chemical warfare agent simulants

ZHANG Shiyu, YAO Yiting, DONG Chenshan, ZHANG Ruquan, YANG Hongjun, GU Shaojin, HUANG Jingjing, DU Jiehao

Journal of Textile Research. 2024, 45(06):  134-141.  doi:10.13475/j.fzxb.20230703201

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Objective Metal-organic frameworks (MOFs) possess an exceptionally high active specific surface area and exhibit structural and functional diversity, among other characteristics. Studies have shown that MOFs have demonstrated effective degradation of chemical warfare agents. However, the crystal morphology of MOFs powders limits their practical application in catalytic degradation processes. To address this issue, the utilization of a coating modification technique becomes crucial. This technique leverages the adhesion and secondary reactivity of hydrophilic modified coatings to facilitate the in-situ growth of MOFs crystals on the modified polypropylene (PP) surface. This research aims to boost the MOFs loading on the substrate and improve the stability of the MOFs. Overall, this method is significant for developing textiles tailored for the rapid removal of chemical warfare agent simulants.

Method PP nonwovens were immersed in a mixed solution of tannic acid (TA) and aminopropyltriethoxysilane (APTES) to prepare TA-APTES coating modified PP nonwovens. The modified PP with the TA-APTES coating was sequentially submerged in the solution of zirconium tetrachloride and 2-aminoterephthalic acid, enabling the in-situ growth of zirconia-based metal-organic frameworks (UiO-66-NH₂) on the PP surface to prepare a PP/TA-APTES/UiO-66-NH₂ (PTAU) fiber-based composite. The surface morphology, composition, and structure of the composite were characterized by scanning electron microscopy, Fourier transform infrared, X-ray diffraction and X-ray photoelectron spectroscopy(XPS), respectively. The loading of MOFs in the composite was characterized by inductively coupled plasma optical emission spectrometry and the wettability of the composite was characterized by static water contact angle test. Moreover, the degradation performance of the composite on chemical warfare agent simulants was evaluated.

Results Compared with the unmodified PP, the surface of PP composite modified by TA-APTES coating became rough which is conducive to the growth of MOFs on the surface of PP. The infrared spectrum showed the characteristic peaks of the modified TA-APTES and UiO-66-NH₂. The XRD pattern of the PP after TA-APTES coating confirmed that the UiO-66-NH₂ crystalline form remained unchanged in the composite. The XPS characterization revealed the elemental valence composition of the composite surface before and after the reaction. The thermogravimetric testing suggested that the final residual mass percentage of the original PP nonwovens was 1.3%, while the residual mass percentage of PTAU composite was 17.4%, indicating that the thermal stability performance of the treated PP was improved. These results showed that the MOFs was successfully modified on the surface of TA-APTES coating on PP. Additionally, TA-APTES coatings significantly changed the wettability of PP composites and enhanced the loading capacity of MOFs on the composite surface to 20.96%. The UV spectrum of dimethyl p-nitrophenyl phosphate (DMNP) degradation catalyzed by composite demonstrated that the characteristic peak of DMNP at 270 nm gradually decreases and the characteristic peak of the hydrolysis product p-nitrophenol at 400 nm gradually increases, and the degradation rate of the composite reached 100% after 30 min. The half-life of degradation of PTAU composite was 4.8 min.

Conclusion TA-APTES coating was used to modify PP nonwoven to construct the active site of MOF nucleation, which promoted the uniform distribution and robust growth of UiO-66-NH₂ on PP surface. The inductively coupled plasma optical emission spectrometry results showed that the loading of UiO-66-NH₂ in composite was increased by TA-APTES coating, reaching up to 20.96%. The experimental results demonstrate that TA-APTES coating can effectively improve the surface wettability of PP composite material from hydrophobic to hydrophilic, and greatly improving its catalytic degradation efficiency in aqueous solution. The catalytic degradation experiment showed that the catalytic degradation efficiency of PTAU composite was further improved, the conversion rate reached 100% in approximately 30 minutes, and the degradation half-life was about 4.8 min.

Apparel Engineering

Clothing silhouette recognition based on detection of key points

TAO Jinzhi, XIA Ming, WANG Wei

Journal of Textile Research. 2024, 45(06):  142-148.  doi:10.13475/j.fzxb.20230604901

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Objective The clothing silhouette serves as an important feature for distinguishing and describing garments, and it holds significant relevance in various aspects such as consumer guidance in purchasing, personalized recommendations and customization services, design and production optimization, as well as market trend analysis and research. Previous research generally relied on manually defined key areas and designed complex algorithms to extract key point dimensions, resulting in low efficiency in discrimination. In order to achieve accurate and rapid clothing silhouette classification, this research focuses on runway dresses and proposes a clothing silhouette classification algorithm based on key point detection.

Method A convolutional neural network was used in this research to predict ten key points including shoulders, chest, waist, hips, and bottom hem. These key points allow for the extraction of the clothing's silhouette from complex backgrounds, resulting in a silhouette image composed of lines. To extract simple clothing silhouette features, the DenseNet network was enhanced by incorporating the Sobel edge detection algorithm. The extracted features were then compared with the features extracted from a relative standard silhouette database using the cosine similarity algorithm. This approach ultimately enables the discrimination and classification of clothing silhouettes.

Results The average error rates for each key point ranged from 0.046 to 0.205. The key points on the sides of the bottom hem had relatively larger average error rates of 0.205 and 0.204. This is mainly due to the deformation of the bottom hem caused by the model's walking movements, making it challenging to discern the key points of the dresses with trailing hemlines caused by stage lighting reflections. The shoulder key points had the lowest error rates, with values of 0.046 and 0.053. This is because the clothing texture stands out more compared to the surface of the human body, resulting in higher accuracy in key point localization. The waist key points had slightly higher error rates with values of 0.071 and 0.081. This is often due to the design of division lines at the waist in order to highlight body proportions, making the waist key points relatively easier to identify. In addition to quantitative analysis for evaluating the model, this study also performed key point detection on five representative images with different silhouettes. For the experiment, 100 images of A-shaped silhouettes, 100 images of X-shaped silhouettes, and 58 images of H-shaped silhouettes were selected. Compared to two commonly used convolutional neural networks, i.e., VGG16 and ResNet50, the DenseNet-based silhouette classification showed a some advantage in accuracy. However, the average accuracy rate reached only 94.7%, which is not a significant improvement compared to other methods proposed in previous studies. When a Sobel layer was added to the DenseNet network, the edge features were sharpened, leading to improved accuracy in silhouette classification for various body shapes, under which circumstances, the average accuracy rate reached 95.9%.

Conclusion In this paper, an intelligent classification method for clothing silhouette based on key point detection is proposed. Automatic extraction and classification of clothing silhouettes is achieved by key point detection and similarity algorithm. The experimental results show that the method leads to 95.9% classification accuracy in silhouette recognition, and the F1 score reaches 0.941. In order to improve the accuracy of convolutional neural network's extraction of edge features, the Sobel edge extraction algorithm is applied to the feature extraction process of DenseNet network. For comparison, whilst the convolutional neural network is able to learn the edge features in the image, the silhouette recognition method based on key point detection proposed in this paper is applicable to the silhouette recognition of various types of garments, which provides ideas and references for future silhouette classification research.

Parametric characterization method of clothing fold morphology

WANG Yipin, LI Xiaohui

Journal of Textile Research. 2024, 45(06):  149-154.  doi:10.13475/j.fzxb.20221102601

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Objective In the context of intelligent and automated clothing structure design, there are many problems in the quantitative representation of fold morphology, such as a wide variety and a lot influencing factors. In order to solve this problem, this paper proposes a parametric characterization method for clothing fold morphologies, and establishes the mapping relationship between its two-dimensional plane style and three-dimensional structure, so as to realize the automatic generation of fold personalized patterns.

Method The parametric theory was used and a series of parameter values were set. Relevant parameters were adopted to constrain and describe the structural dimensions of geometry. By combining the structural drawing principle of folds and the relationship between internal fold structures, 14 characteristic parameters that can quantify the fold morphology were proposed. Five skirts of the same fabric were prepared as experimental samples, including a total of six common pleated styles. There were 22 sets of experiments designed from these 5 samples. In the experiment, physical photos of clothing folds were taken under the same angle of view and the same plane. Then the photos were subjected to image processing for feature parameter extraction.

Results From the quantification results of the fold images of specimen A-E, it can be seen that each fold in the sample can be decomposed into multiple single folds of different sizes and orientations to characterize. These folds can be quantified with the extracted 14 characteristic parameters and 11 representative folds were extracted from five specimens. Estimates of the parameters in these folds were found. Then the data were compared with their actual measurements. SPSS were utilized to pair estimates and measurements for different types of folds. The results show that the folds, which quantified by this method, has a significant correlation between the estimated and measured values used for testing. At the same time, no significant difference exists between the estimated and measured values of the folds at the 95% confidence interval, indicating that the folds estimated and measured values are relatively close, and this method has a certain accuracy.

Conclusion After studying the quantification ability of different characteristic parameters on folds and conducting related experiments, the results show that each characteristic parameter extracted in this paper has practical application value. At the same time, this method has high accuracy. No significant difference exists between the experimental verification data and the data read by the tester. This method is more systematic. It quantifies and characterizes various factors affecting fold morphology through mathematical means, which can realize the systematic and non-subjective evaluation of fold morphological characteristics. This method is flexible and has good quantification capabilities for a variety of different types of folds. The fold parameterization method proposed in this paper can effectively realize the quantitative characterization of clothing fold morphology. It has practical application and feasibility in the parameter acquisition and style recognition of clothing intelligent plate making, which provides a new research idea for the intelligent development of clothing engineering.

Digital restoration of women's costumes depicted in ancient painting of "A Palace Concert"

HUANG Zhiwei, SHI Yajie, LU Feng, LI Qing, XUE Zhebin

Journal of Textile Research. 2024, 45(06):  155-164.  doi:10.13475/j.fzxb.20230705901

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Objective The traditional process of restoring ancient costumes relies on physical artifacts as a basis, which often leads to cumbersome and time-consuming restoration procedures due to factors such as the condition of cultural relics, restoration processes, and the experience of researchers. The restoration of ancient costumes necessitates broader exploration and the quest for a more scientific methodology to serve as guidance.

Method Taking the tea-serving maiden in the ancient painting of "A Palace Concert" as the subject, a digital approach was adopted to restore the Tang Dynasty women's costumes depicted in the painting. This approach involved painting restoration using digital techniques, inferencing costume styles, sizes and other information through the use of literature and aesthetic principles, sample production using digital pattern-making tools, and virtual costume creation and display using three-dimensional virtual-reality technology. The evaluation system was constructed using the Analytic Hierarchy Process (AHP) and consists of four primary criteria and eleven secondary criteria. The weights of each criterion were calculated, and the restoration results were evaluated using the fuzzy comprehensive evaluation method.

Result A comprehensive evaluation system and criteria for the restoration of women's costumes depicted in the Painting "A Palace Concert" were constructed, including four primary criteria, which were "Overall Styling", "Costume Construction", "Fabric Selection", and "Craftsmanship", as well as eleven secondary criteria to assess the effectiveness of costume restoration. Using the expert assessment method, weights were obtained for both the primary and secondary criteria. The primary criteria assigned 0.243 3 weight to "Overall Styling", 0.378 9 to "Costume Construction", 0.162 3 to "Fabric Selection", and 0.188 0 to "Craftsmanship", among which, "Costume Construction" had the highest weight. The secondary criteria assigned "Costume Bodice" and "Costume Style" with relatively high weights, with values of 0.59 and 0.488 7, respectively. Their comprehensive weights were 0.143 5 and 0.185 2 respectively, indicating that the restoration effectiveness of the costume bodice and style silhouette, which are the main visual perception elements, significantly influence the final restoration outcome of the women's costumes. The virtual restoration results were evaluated for the secondary criteria, and the evaluation degrees of "Very Good", "Good", "Fair", "Poor", and "Very Poor" were obtained for corresponding elements. The evaluation results for the secondary criteria were then integrated and statistically analyzed. It can be observed that all secondary criteria received evaluation degrees of "Very Good" greater than 35%, and there were seven elements "Costume Silhouette", "Costume Sleeves", "Costume Collar", "Fabric Material", "Fabric Color", "Fabric Pattern" and "Piece Seaming" with evaluation degrees greater than 40%. This indicates that the restoration effectiveness for all secondary criteria was rated as "Very Good". Furthermore, the evaluation was recalculated with consideration of weights for the primary indicators and overall restoration effectiveness. All primary indicators were rated as "Very Good", with the breakdown as follows:"Overall Styling" at 40.25%, "Costume Construction" at 41.85%, "Fabric Selection" at 47.68%, and "Craftsmanship" at 42.17%. The final evaluation result for the "Overall Restoration Outcome" was categorized as "Very Good" at 41.32%. These data demonstrated that the restoration of the primary criteria and the overall effect of the Qi-chest Ruqun costume for the tea-serving maiden in the Painting of "A Palace Concert" were highly successful.

Conclusion By using digital techniques for restoration and incorporating literature and other images, combined with the utilization of CLO 3D software, it is possible to achieve digital restoration of ancient women's costumes depicted in the Painting of "A Palace Concert" and provide a viable methodology for exploring the digital restoration of ancient costumes. In terms of evaluation, the "Overall Styling", "Costume Construction", "Fabric Selection", and "Craftsmanship" have varying degrees of impact on the authenticity of virtual costume restoration based on the painting. Among them, the "Costume Bodice" and "Costume Style" have a relatively higher influence, indicating that the overall visual presentation is the most critical factor influencing the effectiveness of costume digital restoration. The final restoration results received evaluations of "Very Good" and "Good," with a combined percentage of over 70%, demonstrating that digital restoration based on ancient paintings can effectively simulate and restore ancient costumes with good visual effects and feasibility.

Parametric and regeneration design of Badayun patterns

ZHANG Suya, CUI Rongrong, WANG Zhicheng, JIANG Wenqin, XU Pinghua

Journal of Textile Research. 2024, 45(06):  165-172.  doi:10.13475/j.fzxb.20230702601

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Objective Traditional patterns possess rich cultural connotations and unique aesthetic characteristics. This study aims to reinterpret and recreate the morphological composition of traditional patterns, injecting them with a sense of contemporaneity and innovation. By doing so, it seeks to infuse contemporary designs with distinctive artistic charm and provide consumers with diverse choices and cultural experiences. Currently, researchers primarily focus on the cultural connotations and formal composition of patterns, resorting to manual drawing for their reinterpretation, while lacking applications for rapid digital generation. To enhance the efficiency of innovative design for traditional patterns, a parametric deconstruction and regeneration method is proposed, enabling the rapid generation of pattern forms and color variations.

Method This study focused on the Badayun patterns, analyzing its artistic value and morphological structure. The patterns were divided into three categories, i.e., filling, decoration, and skeleton, which were further deconstructed into basic graphical elements. By quantifying the parameters of each element, a morphological fitting formula was constructed. Modeling was then carried out using Rhino software and its Grasshopper plugin to establish a foundational pattern model. The model included the establishment of pattern deconstruction, primitive library, parameter library, rule library, and parametric expression and recombination, which eventually formed patterns with different shapes and parameters. Furthermore, color extraction and clustering algorithms were employed to extract and cluster colors from different scenarios, resulting in diverse color schemes. Additionally, automatic coloring was applied to the interior regions of the generated patterns.

Results By combining traditional patterns and parametric modeling techniques, this study presented a parameterized deconstruction and regeneration method based on the Badayun pattern. The method successfully achieved the parameterized regeneration of traditional patterns with different forms and color styles. Using the floral element of the Badayun patterns as an example, the element was deconstructed parametrically to generate locally varying graphical effects under different parameters. Furthermore, an improved binary K-means adaptive clustering algorithm was employed to extract color factors from samples, yielding color analysis charts of typical Badayun patterns from different periods. It included the main colors of the Badayun patterns in the Song, Ming, and Qing dynasties, the RGB values of the corresponding main colors in different periods, and the color proportions of different colors in the overall pattern. Based on the generated line drawings of patterns in different forms, an automatic transfer coloring algorithm is utilized to derive various coloring effects for the same pattern. The well-designed Badayun patterns could be applied in multiple fields and transformed into product textures through a parametric platform, facilitating aesthetic dissemination and transforming functional utility in various products. It formed a new way of transforming the qualitative expression of pattern regeneration design into quantitative expression, which could quickly generate a large number of traditional pattern design schemes and effectively improve the design efficiency.

Conclusion This paper proposes a parametric model-based design method for Badayun patterns, which can generate different styles of patterns according to different parameter settings. The method uses computer technology to achieve an integrated design of line drawing, structure, and color assignment, which can quickly and flexibly adjust and control the form and style of the patterns, compared to the traditional design method. The method improves the design efficiency and creativity. Through case analyses, the paper demonstrates the application value of the method in garment pattern regeneration design and graphic design in the digital era. The parametric model-based design method for decorated lattice patterns provides an effective technical means for the regeneration and innovation of traditional patterns, and a new entry point for graphic design in the digital era.

Machinery & Equipment

New generation of digital manufacturing system for textile printing and dyeing

YUAN Mukun, YU Guangping, LIU Jian, LI Jian, WANG Zhiguang, YUAN Mingzhe, GUO Qingda

Journal of Textile Research. 2024, 45(06):  173-185.  doi:10.13475/j.fzxb.20230402501

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Objective The textile industry, as a part of traditional and extensive manufacturing, features long and complex processes with specific requirements at each step. The widespread lack of informatization and automation results in low production efficiency and unstable quality control, demanding higher levels of process collaboration and control optimization. Additionally, being labor-intensive, it faces an increasing shortage of human resources. The industry's poor foundation in componentization and intelligence, alongside its weak flexibility and reconfiguration capabilities, faces pressures from resource scarcity, high energy consumption, and environmental costs, complicating the fulfillment of customization, diversity, small batches, and quality-focused transformation demands. The limitation of traditional digital manufacturing technologies on industry upgrades becomes apparent. The integration of the Industrial Internet, internet of things (IoT), big data, cloud computing, artificial intelligence (AI), and human-machine collaboration in new-generation digital manufacturing for textile printing and dyeing aims to meet demands for personalized customization, dynamic process reconstruction, and lean quality management. Textile production, spanning from negotiation to warehousing, encompasses various management areas like orders, design, and quality. Sharing data across these areas enables collaborative decision-making, supporting production and operational decisions through intelligent analysis and optimization, marking a key strategy in advancing collaborative manufacturing driven by digital information.

Method Addressing the digital transformation pain points in the textile printing and dyeing industry, such as decentralized cross-domain production data, weak interaction across management systems, and frequent manual involvement, the paper introduces a new-generation digital manufacturing system architecture for the textile and dyeing sector. It establishes a data hub for the business production process to collect and integrate data from various stages. By constructing decision-support components, the system enhances the customization capacity of the manufacturing system, meeting the optimization and control needs of different companies at various decision-making levels. Finally, it develops a comprehensive digital control system. Through creating a management cockpit, it achieves digital control over orders, equipment, energy, and environmental safety, fulfilling the industry's needs for integrated intelligent decision-making across systems, merging business and control systems, and a closed-loop control model from decision to execution.

Results Paper proposes a new-generation digital manufacturing system framework for textile printing and dyeing to meet the needs of networked and intelligent industrial upgrading such as data perception, information fusion, knowledge reasoning, business interaction, and human-computer collaboration in there. It combines the whole process of business production to establish data center to achieve cross-system integration of integrated intelligent decision-making, build a pool of decision support components for the whole production decision-making field, which is used to promote the integration of business systems and control systems, and set up management cockpit, order digital control system, equipment digital control system, energy digital control system and environmental protection and security digital control system based on the integration of the whole business production process data. Finally, the model of decision-execution closed-loop feedback is formed to realize the information control of the whole process of business and production. A textile dyeing and finishing company in Guangdong, based on the system framework, upgraded the digital manufacturing technology in its dyeing workshop. Compared to 2019, in 2021, the digital intelligent dyeing demonstration workshop saw its per capita output value increase from 1.140 4 million yuan per person to 2.791 1 million yuan per person, with production efficiency up by 145.0%. The product yield rate rose from 88.2% to 96.2%, marking a 9.1% quality improvement. Energy consumption per unit of output value decreased from 465.12 kgce per ten thousand yuan to 316.71 kgce per ten thousand yuan, enhancing energy utilization by 31.9%. In the digital intelligent shaping demonstration workshop, the per capita output value grew from 0.455 2 million yuan per person to 1.046 6 million yuan per person, a 129.9% increase in production efficiency. The product yield rate improved from 95.1% to 97.6%, a 2.6% quality increase, and energy consumption per unit of output value was reduced from 1 759.83 kgce per ten thousand yuan to 1 144.87 kgce per ten thousand yuan, resulting in a 34.9% increase in energy utilization. Significant improvements were achieved in terms of production efficiency, product quality, and energy utilization.

Conclusion Textile printing and dyeing industry already gets a basic digital foundation and information level, with the process of deploying advanced computer numerical control equipment with functions such as equipment communication, status monitoring, process monitoring and fault diagnosis in weaving, dyeing, sizing, color matching, auxiliaries' transmission and distribution and dyestuff transmission and distribution. The popularity of software systems such as enterprise resource planning (ERP), manufacturing execution system (MES) and scheduling system (APS) applied in enterprise procurement, production, marketing and management can provide a timely channel to understand the operation status of workshop production, and significantly reduce the defective rate of products and improve the production operation level of enterprises. The future development and innovation direction of the textile printing and dyeing industry is based on the needs of production enterprises to increase efficiency, reduce consumption, and optimize management. By perceiving production data to form industry domain knowledge, creating a common operation and management platform, and strengthening the application and promotion of this platform in upstream and downstream enterprises, it aims to integrate the supply chain, production chain, and sales chain, forming a collaborative operation and management system for the entire value chain.

Rigid-flexible coupling wear analysis of spatial linkage weft insertion mechanism

LI Bo, LIU Xuning, GUO Jie, HU Kai, CHANG Boyan, WEI Zhan

Journal of Textile Research. 2024, 45(06):  186-192.  doi:10.13475/j.fzxb.20230404401

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Objective In calculating the wear of the kinematic pair in the spatial linkage weft insertion mechanism with clearance, the role and change process of the clearance in the wear process of the hinge clearance cannot be accurately expressed if simply considering the clearance of the flexible hinge or simply consider the flexible deformation of the rod. Therefore, in order to improve the calculation accuracy of clearance impact wear prediction, the influence of various factors on the system motion output should be considered comprehensively, so as to meet the requirements of high speed, light weight and heavy load of the mechanism and improve the operation accuracy of the mechanism.

Method Firstly, combined with the Lankarani-Nikravesh and Bai model, the variable stiffness and damping discontinuous contact impact force model was established. The improved Coulomb friction model was used to describe the friction between the shaft pin and the sleeve of the rotating hinge with clearance mechanism, and the system dynamics was modeled by Lagrange method. Secondly, the spatial linkage was selected as flexible object, and the rigid-flexible coupling dynamics simulation of the spatial linkage weft insertion mechanism was carried out by combining Ansys and Adams methods. Finally, the dynamic simulation response results of the sys-tem were combined with the Archard model.

Results In the rigid-flexible coupling system, the maximum stress of the spatial linkage was distributed near the rotating pair, and the maximum deformation distribution of the unit displacement was also at the hinge point of the two support frames. As the clearance was increased to r = 0.5 mm, the component flexibility failed to effectively alleviate the speed fluctuation caused by the clearance impact during the process of the rapier head sliding out of the shuttle, while in the weft handover process, the component flexibility effectively slowed down the high-frequency fluctuation of the rapier head acceleration. When the clearance r = 0.15 mm, the relative sliding distance showed a higher value in the two working states of weft handover and rapier head return. When the clearance was increasd to r = 0.5 mm, its maximum value did not increase significantly compared with the clearance r = 0.15 mm, although the sliding distance fluctuates greatly in the whole period. When the clearance r=0.15 mm, the maximum wear depth of the motion pair appeared in the vicinity of the spindle rotation angle, this was the same as that when the clearance r=0.01 mm. When the clearance was increased to r=0.5 mm, a large number of wear occurred in a wear calculation cycle with a much increased frequency. In such a case, the wear range was no longer concentrated on the fixed area, while the maximum wear depth did not show significant increase. With the increase of the clearance of the kinematic pair, the maximum value of the clearance impact force also was increased, and the wear depth was increased with the increase of the impact force under different clearance conditions.

Conclusion Compared with the pure rigid body mechanism, the flexibility of the component has a greater influence on the acceleration of the rapier head, which can prevent the yarn from breaking during the handover of the rapier head to a certain extent. In the high speed running process of the spatial linkage weft insertion mechanism, the relative sliding of the joint components with clearance in the impact process mainly occurs in the 'fast forward' and 'quick return' stages of the rapier head. Under the condition of clearance r = 0.15 mm, the maximum amplitude of the acceleration oscillation of the rapier head is reduced by 53.2%. When the clearance rises to r = 0.5 mm, although the wear range increases significantly, the wear depth of the clearance does not increase significantly.

Key technology research of bobbin change actuator suitable for multiple bobbin types

MAO Huimin, TU Jiajia, SUN Lei, DAI Ning, SHI Weimin

Journal of Textile Research. 2024, 45(06):  193-200.  doi:10.13475/j.fzxb.20230304201

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Objective In a traditional knitting workshop, bobbin changes are carried out manually. This highly repetitive and low automation production method makes it difficult and inefficient to change the top layer bobbins on the yarn frame. Although different sizes of cylindrical and conical bobbins are used with circular knitting machines, the bobbin clamping mechanisms are available only for specific sizes and types of bobbins, causing problems for bobbins with different inner diameters and tapers. Therefore, this research focuses on designs an bobbin change actuator for different types of bobbins to achieve automated circular weft knitting.

Method According to the structural characteristics of the yarn frame and the process of bbbin replacement in the knitting machine, this paper designed a bobbin change actuator composed of a clamping mechanism, a brake mechanism, a clutch mechanism, a yarn pushing mechanism, a flip mechanism, and son on. The actuator was expected to adjust the contraction size of the clamping jaws and the angle between the jaws through the external expansion motor and the external expansion cylinder respectively, for different types of bobbin gripping. In order to solve the situation of symmetrical flare of the yarn frame bar, a flip mechanism was designed to drive the gripper mechanism for 180° rotation to achieve A/B bobbin replacement. After completing the design, the process of bobbin changing was simulated to verify the feasibility of the bobbin change actuator. In addition, in order to improve the operating life and stability of the bobbin change actuator, ANSYS Workbench software was used to simulate the exhaustive mechanics of the jaws with different diameters and lengths.

Results The simulation results showed that when the length of the jaws was unchanged, the stress on the jaws was decreased with the increase of the diameter of the jaws, while when the diameter of the jaws was unchanged, the stress on the jaws was increased with the increase of the length of the jaws. According to the minimum inner diameter of the guide plate and the requirements of the gripping stability of the jaws, the diameter of the jaws was selected as 18 mm, and the length of the jaws is 58 mm. At this time, the deformation of the jaws is 0.1 mm, and the maximum equivalent stress was 29.7 MPa, which was smaller than the permissible stress of the 6060-T6 aluminum alloy, indicating satisfaction of the requirements for the yarn cylinder gripping with operation stability of the. After that, the experimental prototype was made and the gripping experiments of cylindrical and conical cylinders of different specifications were carried out. The experimental results showed that the gripper has a maximum external diameter of 65 mm and a maximum external taper of 15°, capable of gripping yarn tubes with three different sizes with good stability, among which the maximum mass of the gripped bobbin was 6 kg, and the minimum internal diameter of the gripped bobbin was 20 mm.

Conclusion This paper analyzes the components and motion principles of each mechanism of the bobbin change actuator, carries out static simulation of the jaws of different diameters and lengths by using ANSYS Workbench software, and identified the optimal jaws diameter to be 18 mm and the jaws length 58 mm, meeting the design requirements. A prototype was developed, and the gripping experiments of cylindrical and conical cylinders of different specifications were carried out, and the experimental results proved that the bobbin change actuator is capable of gripping cylindrical bobbins and conical bobbins of different shapes and inner diameters. The automatic bobbin changes actuator introduced in this paper has been applied to a circular weft knitting production line in Guangdong, and it could be extended to textile production lines with wide application prospects.

Comprehensive Review

Research progress of nanofiber structure prepared by electrospinning

LIU Sitong, JIN Dan, SUN Dongming, LI Yixuan, WANG Yanhui, WANG Jing, WANG Yuan

Journal of Textile Research. 2024, 45(06):  201-209.  doi:10.13475/j.fzxb.20230103602

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Significance With the rapid development of nanotechnology, the application of nanofiber materials in the fields of energy storage, catalytic filtration, biomedicine, food engineering and sensors has always attracted the attention of researchers because of its good continuity, high specific surface area and large aspect ratio. However, an effective preparation method has always constrained the development of nanofibers. Electrospinning technology, as the only method that can directly and continuously prepare nanofibers, has had a profound impact in the field of nanofiber material preparation since its birth and patent application in 1934, because of its simple device, convenient operation, low cost and other advantages. Electrospinning technology is a technology that uses polymer as a template to prepare ultrafine fibers with adjustable structure and diameters ranging from nanometer to micrometer under the combined action of high voltage electric field and Taylor cone. Because the nanofibers prepared by this technology have the advantages of large specific surface area, easy structure control and easy functionalization, it has wide application potential in the field of nano-functional materials.

Progress In recent years, the research work of electrospinning technology has mainly focused on the process optimization, mechanism discussion, functional modification and structural multi-level of nanofibers. With the rapid development of electrospinning technology, the spinning liquid system that can be spun has gradually expanded from polymer to biological macromolecules, inorganic substances and organic/inorganic composites. According to different fiber structures, spinning liquid system and spinning mechanisms, the electrospinning technology has been developed from the classical electrospinning to the coaxial electrospinning, parallel electrospinning, conjugated electrospinning, off-axisl electrospinning, and single-axis electrospinning by improving the spinning device, adjusting the spinning parameters and combining the post-processing methods. With the continuous improvement of spinning efficiency, nanofibers have gradually developed from simple smooth filaments to diversified morphology and multi-level structure, and the application field has also developed from single function to multi-function and multi-function coordination. With the deepening of research at home and abroad, the remarkable achievements of electrospinning technology in the preparation of various structured nanofibers provide a feasible technical reference for the control of oriented nanofiber structure. Therefore, at present, achieving the designability of nanofiber structure and exploring the application field of nanofiber materials are one of the key directions for researchers to develop electrospinning technology at this stage.

Conclusion and Prospect In order to further study the electrospinning technology and the structure design of nanofibers, realize the directional structure control of nanofibers, and effectively improve the specific surface area, mechanical properties and morphology uniformity and order of nanofibers. This paper summarizes the structural characteristics, preparation methods and electrospinning mechanism of different nanofibers based on solid nanofibers, porous nanofibers, hollow nanofibers, nanocables and Janus nanofibers, compares the research progress and achievements of electrospinning technology in the preparation methods, formation mechanisms and structure control of different nanofibers, and it further shows that electrospinning technology has broad application potential in realizing nanoscale oriented structure control of nanomaterials. At present, electrospinning technology is one of the most promising preparation methods for preparing nanofibers, although there are many problems to be solved, such as the inability to produce on a large scale, the existence of barriers to the lower limit of fiber diameter, the poor mechanical properties of fibers, and the difficulty in solvent recovery, with the continuous deepening of theoretical research on electrospinning technology and the continuous emergence of novel fiber structures, electrospinning technology is bound to have a broader development space in the preparation of controllable nanofiber structures, and will also promote the development of nanomaterials to functional multi-domain, structural diversification and environment-friendly.

Research progress in biomass-based carbon aerogels in energy storage device

GAO Zhihao, NING Xin, MING Jinfa

Journal of Textile Research. 2024, 45(06):  210-218.  doi:10.13475/j.fzxb.20221204802

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Significance With the increasing scarcity of oil, coal and other resources, the development of green and efficient energy storage materials has gradually become the focus of relevant research. Carbon aerogels have been recognized as one of the most promising candidate for energy storage materials due to its high porosity, low density, good electrical conductivity and high temperature resistance. Biomass materials are the most cost-effective, environmentally friendly and sustainable precursors for fabricating carbon aerogels. The preparation of biomass-based carbon aerogel and its application in the field of energy storage have attracted much research attention in the recent years. The release of China's "carbon peak and carbon neutralization" strategy further promotes its research and application. To foster the development of biomass-based carbon aerogels, a systematically overview on biomass-based carbon aerogels for energy storage devices was carried.

Progress Based on the differences in raw material form, the preparation methods of biomass-based carbon aerogel are summarized as gel carbonization, hydrothermal carbonization and direct carbonization. Three preparation methods including the technological process, application range and advantages/disadvantages are compared and analyzed. At present, there are biomass-based carbon aerogels which are widely used, namely unmodified pure biomass-based carbon aerogels and composite biomass-based carbon aerogels modified by metal doping and heteroatom doping. This work summarizes the latest research progress in energy storage devices such as supercapacitors and lithium-ion batteries. Material design and microstructure are the main factors affecting the electrochemical performance of biomass-based carbon aerogel. Suitable doping and uniform nanostructure will help to improve its comprehensive performance. The energy storage device using this biomass-based carbon aerogel as the electrode shows superior rate capability and cycling performance during the test. In addition, relevant studies have shown that biomass-based carbon aerogels can also be used as electrodes for fuel cells, zinc-air batteries, and lithium-sulfur batteries. Some researchers attempted to use it to modify the battery separator and have achieved certain results.

Conclusion and Prospect As a new type of functional aerogel, biomass-based carbon aerogels possess excellent properties of aerogel (high specific surface area, high porosity and low density), carbon materials (heat resistance and electrical conductivity) and biomass materials (economical and biodegradable). Based on these advantages, biomass-based carbon aerogel has been preliminarily applied in supercapacitors and some secondary batteries. In recent years, it has becomes one of the hotspot research fields in energy storage materials. Innovative research methods and theories are constantly emerging around the functional preparation, material characterization and product application of biomass-based carbon aerogels. However, there are still some uncertainties and challenges in the process of industrial production and application of biomass-based carbon aerogels. Future research can be focussed on the following aspects. ① Development of new biomass precursors with more attention to be paided to the utilization rate of biomass materials and the impact of raw materials on the structure and properties of carbon aerogel. ② Innovation and improvement of the preparation process of biomass-based carbon aerogels, aiming for large-scale production of carbon aerogels with uniform structure and excellent performance on the basis of reducing cost and energy consumption. ③ Replacement of man-made materials with natural renewable materials (such as silk fibroin extracted from cocoon silk), in forming the combination with biomass-based carbon aerogel, so as to improve the overall environmental protection of energy storage devices. ④ Further exploration into the influence mechanism of production process including composite process on biomass-based carbon aerogels to achieve controllable optimization of the microstructure and comprehensive properties of carbon aerogels so as to expand application into more prospective emerging material fields.

Research progress of flexible textile pressure sensor based on MXene

WANG Jian, ZHANG Rui, ZHENG Yingying, DONG Zhengmei, ZOU Zhuanyong

Journal of Textile Research. 2024, 45(06):  219-226.  doi:10.13475/j.fzxb.20230605002

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Significance As intelligent wearable technology has developed, flexible pressure sensors have become widely used in textiles. Compared with previous sensors, it has light weight, bendability, small thickness and good flexibility. This means it plays a crucial role in the monitoring of human physiological activities, health movement, disease detection, human-computer interaction and other fields. For flexible sensors, active materials with high electrical conductivity and support materials with significant flexibility are selected to obtain ideal electrical conductivity and high ductility. In recent years, MXene, a two-dimensional layered structural material with excellent electrical conductivity, large surface area and an exceptional layered structure, has been widely used in medical monitoring, robotics, human-computer interaction and other fields.

Progress The research progress of flexible textile pressure sensors based on MXene in recent years is reviewed. The excellent performance of MXene has potential application prospects in various fields. Different preparation methods may lead to significant differences in the performance of the prepared MXene. Therefore, the preparation method of MXene is introduced. That is, hydrofluoric acid (HF) etching, in situ hydrofluoric acid (HF) etching, molten salt etching, concentrated alkali method, solution phase flocculation method, electrochemical method and hydrothermal method. Then the main mechanism of MXene materials in piezoresistive, capacitive, piezoelectric and triboelectric pressure sensors is analyzed, and different flexible sensors based on MXene materials are listed. Finally, the classification and performance of its applications are discussed, including health and motion monitoring, human-computer interaction and spatial haptic mapping of integrated arrays.

Conclusion and Prospect It is reported that multi-functional flexible sensors made from MXene materials have great potential in the fields of human motion monitoring, disease prediction, health monitoring and human-computer interaction. Although the research of MXene-based flexible sensor has made excellent progress, it still has some shortcomings, such as short working life and few functional characteristics, and faces great challenges in the future practical application. Through summary and analysis, it is concluded that the future research development direction can be developed from the following three aspects: 1) The working life needs to be extended. The practical realization of flexible pressure sensors in health and medical monitoring, human-computer interaction and other fields needs to improve the service life of functional devices, which is related to the durability, mechanical stability and chemical stability of devices; 2) More characteristics should be given, such as biodegradability and biocompatibility should be added in the medical field; 3) Large area integrated array is an urgent development direction for robot and interactive human-machine interface applications.

Review on automatic grasping technology and arrangement methods for garment pattern pieces

WANG Jianping, SHEN Jinzhu, YAO Xiaofeng, ZHU Yanxi, ZHANG Fan

Journal of Textile Research. 2024, 45(06):  227-234.  doi:10.13475/j.fzxb.20230506802

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Significance Garment manufacturing and processing are progressing to intelligent manufacturing following the concept of "machine instead of man". However, in the off-loading sector of the garment industry, the stacking of cut pieces from the cutting machine is currently carried out primarily by manual gripping and separation, which forms a "bottleneck" limiting the further intelligent development in garment manufacturing. Focusing on this problem, this paper reviews and summarizes the research progress in automatic gripping technology and arrangement methods for garment ply, aiming to provide reference for the development of gripping methods for a variety of fabric materials and shapes.

Progress This paper reviews the current global research status of intelligent gripping technology and the arrangement methods for garment pattern pieces. Specifically, the principles and applicable fabric ranges of air-pressure suck gripping, electrostatic gripping, needling gripping, robotic gripping and soft finger gripping are analyzed, and their layouts on the fabric surface are summarized and divided into three categories, i.e. blind gripping, single-point gripping and multi-point collaborative gripping. Literature shows that the soft finger gripping technology has a broader application potentials and would play an important role in future development of intelligent grasping technology for garment pattern pieces. It is envisaged that the intelligent gripping method combined with machine vision technology and other artificial intelligence technology is an important research direction for the future.

Conclusion and Prospect According to the literature research, Bernoulli suction cups work better with leather than fabrics, whereas negative pressure suction cups are often appropriate for moving a whole stack of materials. Electrostatic is more appropriate for textiles made of chemical fibres. Mechanical gripping and needling are less taxing on fabric material. Needles, however, are better suited for lightweight materials, and they are likely to pierce the material and result in quality issues. Mechanical gripping is more likely to induce creases on the surface of the fabric. Research on Coanda suction cups and soft finger grasping is still in its early stages. The advantages of soft material, easy control, economic efficiency, and gentle finger grasping have made this new type of garment cutting piece gripping technique one of the most marketable. Future gripping technologies should enhance gripping accuracy, repeat positioning accuracy of the gripping head, convenience, economical layout methods, intelligent garment cutting piece gripping, to make a breakthrough in order to better accomplish the goal of "machine instead of man" in garment pattern piece gripping.