Objective In order to improve the flame retardant properties of polyethylene terephthalate (PET), PET-based carbon dots (PET-CDs) were prepared by pyrolysis using PET waste as a precursor, and PET com-plexes (PET-CDs-PET) were prepared by mixing them with PET using physical blending method. The transformation from PET waste to flame-retardant PET was achieved. PET oligomers were prepared by microwave method, and then PET-CDs were prepared by pyrolysis reaction of PET oligomers with ethylenediaminetetraacetic acid. PET-CDs of different qualities were crushed in a pulveriser together with PET slices to obtain four kinds of PET-CDs-PETs with different contents of PET-CDs.

Method Transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier infrared spectroscopy were used to analyse the structure of PET-CDs, and the optical properties of PET-CDs were investigated with the help of fluorescence spectrometer and UV analyser. The effects of different additive amounts of PET-CDs on the flame retardancy of PET were investigated by the limiting oxygen index (LOI), vertical combustion (UL-94), and cone calorimetry. The effect of PET-CDs on the flame retardancy of PET with different additions was also investigated by using a material. The mechanical properties of PET-CDs-PET were investigated by a material strength tester.

Results As far as the structure is concerned, the prepared PET-CDs are quasi-spherical, with uniform particle distribution and no agglomeration. The particle size ranged from 0.44 nm to 4.39 nm, the average particle size was 1.85 nm, the lattice spacing was 0.25 nm, and the surface contained hydroxyl, carboxyl, and amine functional groups. In terms of optical properties, the prepared PET-CDs ethanol solutions showed dark brown colour under indoor natural light and blue fluorescence in UV analyser when irradiated by UV lamp with wavelength of 365 nm. The fluorescence of PET-CDs ethanol solutions was typical excitation wavelength-dependent, with the optimal excitation wavelengths and emission wavelengths of 320 nm and 420 nm, respectively. The absolute fluorescence quantum yield reached 25.73% under the light excitation at 320 nm, and the UV-visible absorption spectrum had an obvious absorption peak at 293 nm. In terms of flame retardant properties, the thermal stability of PET-CDs met the requirements of blending with PET, and the residual carbon of PET was increased by adding PET-CDs into PET. The LOI values of PET-CDs was increased and then decreased after the addition of PET-CDs with different contents, but all of them were higher than that of pure PET. The UL-94 fire ratings were all V-2 with different additions of PET-CDs. The LOI value of PET-CDs 1%-PET was 30%, and there was no significant decrease in the mechanical properties of PET at this additive amount, so the optimal additive amount of PET-CDs was 1%. The total heat release of PET-CDs 1%-PET was decreased by 1.5%, the total smoke release by 8.1%, the peak value of CO by 42%, the peak value of CO₂ by 35.9%.

Conclusion The preparation of CDs from PET waste as raw material can provide a new method for the reuse of waste, and the PET waste can be used in the flame retardant modification of PET materials after the preparation of CDs, forming a green and benign cycle. At the same time, the application of CDs in the flame retardant field not only broadens the scope of its application, but also provides a new flame retardant in this field.

Objective In order to promote the development of multi-functional flexible wearable sensors, it is of great significance to develop a sensor which could sense both strain and temperature. PEDOT:PSS is a conductive polymer with excellent thermoelectric properties, and can be employed as an ideal base material for stretchable strain sensor and temperature sensor. In this research, a composite conductive fiber was prepared by wet spinning method to achieve strain and temperature sensing.

Method The composite conductive fibers with different PU content were prepared by the wet spinning method. The conductivity, Seebeck coefficient, power factor and mechanical property of the composite conductive fiber were measured and analyzed. To verify the ability of this fiber as a strain sensor for motion detection, it was fixed on the index finger and wrist respectively, and the resistance response at different bending angles was measured. Furthermore, the fiber was sewn into a glove, and the temperature-sensing performance was studied.

Results With the increase of PU content, the conductive network was destructed by the non-conductive component, resulting in a decrease in conductivity, but the Seebeck coefficient of the composite remained stable because the thermoelectric material was unchanged. The stress and strain of composite fiber were both increased with the increase of PU content. This fiber showed wide work strain range (0%-90%), high sensitivity and good stability. The finger and wrist were bent for 5 times, the maximum resistance changes were basically the same, indicating that the elastic composite wire fiber sensor has good stability. The tensile deformation caused by wrist bending was larger than that caused by finger bending, the corresponding resistance change rate was also much larger than that caused by finger bending. When it is used as a temperature sensor, the voltage is generated by the temperature difference formed at the two ends of the fiber. With the temperature difference increasing, the voltage was increasing too. To detect the water temperature, the fiber was sewn into the glove. Once the hand touches the beaker filled with warm/cold water, a temperature difference was created between the inside and outside of the glove, then a voltage signal was generated. When holding a beaker containing warm water of about 37 ℃, a positive voltage of about 35 μV was generated. After release, the voltage dropped back gradually. When clenched again, the voltage rises at almost the same height. When holding a beaker with ice water at about 0 ℃, a negative voltage of about 50 μV was generated. After release, the voltage returns to 0. When clenched again, a negative voltage of about 45 μV was generated. The result demonstrated that this fiber has great promise for temperature sensing.

Conclusion The conductive PEDOT:PSS/AgNWs/PU fiber was prepared by wet spinning method. The AgNWs were added to improve the conductivity of the composite fiber. The mechanical properties of PEDOT:PSS could be increased by adjusting the ratio of PU. The PEDOT:PSS/AgNWs/PU composite fiber has good mechanical properties, elongation at break can reach 800%, able to detect 0%-90% strain range, and still maintain good stability under 100 cycles of stretching/recovery. In addition, it can also be used as a temperature sensor to quickly detect human body and environmental temperature, showing great potential in health monitoring.

Objective In recent years, China has made substantial progress in the research and development in silkworms artificial diet and the innovation of breeding technology. Many researchers studied on using artificial diet in the young instars and applying mulberry leaves in the last larval instars, focusing on the growth and cocoon quality of silkwormsbut with little attention on the raw silk. Therefore, it is necessary to study the cocoon quality, silk quality and raw silk performance of silkworms reared with artificial diet in whole instar.

Method The study was carried out by using different origins of silkworm cocoons (silkworm cocoons reared with mulberry leaves of Chunan and Haian, non-factory silkworm cocoons reared with artificial diet in whole instar, and factory silkworm cocoons reared with artificial diet in whole instar) reared with artificial diet and mulberry leaves in whole instar. We tested cocoon width to observe the appearance and morphology. Through reeling, we calculated the number of rushing upon cocoons per myriameter, reelability percentage. Then, the degumming experiment of raw silk was carried out to calculate the gum content of raw silk as well as mechanical performance evaluation. Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction were adopted to characterize the microscopic morphology of raw silk and analysis. In addition, the experimental results were compared by one-way analysis of variance.

Results In terms of appearance, the cocoons of silkworm reared with artificial diet and mulberry leaves in whole instar are oval, and the cocoons of silkworm reared with artificial diet in whole instar are smaller but more orderly. In terms of cocoon quality and silk quality, silkworm cocoons reared with artificial diet in whole instar have a slightly lower amount of total cocoon weight and cocoon shell weight, which is related to the fact that after the silkworms feed with artificial diet, their ingestion is not as good as that of mulberry leaves-breeding silkworms, but the rate of cocoon layer shows higher. In addition, whether or not the form of factory sericulture also has an impact on the cocoon and silk quality performance of silkworms reared with artificial diet in whole instar was also studied. The total cocoon weight and cocoon shell weight of silkworms reared with non-factory sericulture in whole instar are lower, and the length and the fineness of bave are not as good as those of the other three silkworm cocoons. The cocoons of silkworms reared with mulberry leaves in whole instar has less rushing upon cocoons during reeling, better reelability percentage, reelability silk length, and better reelability performance. For raw silk, the surface morphology of raw silk under different feeding methods is basically the same, raw silk gum content of silkworm reared with artificial diet in whole instar is higher, and raw silk gum content of silkworm reared with factory artificial diet of whole instar is the highest. The breaking strength and the elongation at break of raw silk is not significantly different from that of mulberry leave-reared. In addition, there is no significant difference in the secondary structure of raw silk between the whole instar artificial diet and the whole instar mulberry leaves, which all have β-sheet, random coil, α-helix and β-turn structure.

Conclusion There is no significant difference in the secondary structure and performance between the silkworm cocoons reared with artificial diet and mulberry leaves in whole instar, but there are differences in cocoon quality and silk quality, which can provide reference for the related research of artificial diet rearing silkworms. In addition, there is also a certain relationship between the quality of cocoon and silk of silkworms rearing with artificial diet in whole instar and whether it is factory sericulture. Factory sericulture can improve the production technology and growth environment, which will also have an impact on the growth and development of silkworms.

Objective Carbon fiber(CF) reinforced resin matrix composites (CFRPs) have attracted much research attention in due to their good overall performance. However, CFRPs suffer from the problems of weak interfacial bonding between carbon fibers and matrix, and the mismatch of thermal expansion coefficients of the two phase materials brings about interfacial damage during thermal cycling. Existing interfacial modification techniques are difficult to solve the above two problems, and therefore a new solution is proposed in this paper.

Method Optimization of interfacial properties of composites was carried out based on structural adjustment of polypyrrole (PPy) to achieve surface modification by polymerizing a layer of PPy on carbon fiber. The PPy layer with more conjugated structure was obtained by adjusting different polymerization temperature. The interfacial bonding property, thermal expansion property and thermal cycling stability of CFRPs prepared under different polymerization conditions were studied.

Results The results showed that the surface roughness of PPy/CF-0 fibers polymerized at 0 ℃ was higher than that of CF by a factor of 2.09, which was conducive to the anchoring of the epoxy resin on the surface of carbon fibers. Moreover, the PPy on the surface of PPy/CF-0 fibers showed a higher α-α conjugate structure, which led to the negative coefficient of thermal expansion of the composites, and increased the interlayer shear strength and interfacial shear strength of the composites by a maximum of 60 MPa and 47.5 MPa, respectively. The PPy/CF-0 fiber composites also demonstrated excellent thermal cycling stability, and the shear strength was still maintained at more than 70% of the initial value after 100 thermal cycling tests.

Conclusion Compared with unmodified CF, the interlaminar shear strength(ILSS) and interfacial shear strength(IFSS) of PPy/CF-0 fiber-reinforced composites modified by PPy coating reached 88.9 MPa and 65.4 MPa, respectively, which were 1.56 and 1.70 times higher compared with CF, and the shear strength was maintained at more than 70% of the initial value after thermal cycling up to 100 times. The polymerization temperature has a significant effect on the morphology, structure and properties of the PPy layer. Through AFM observation and FT-IR spectra analysis, the surface of PPy/CF-0 fibers prepared by low-temperature polymerization at 0 ℃ has a large roughness and the content of α-α conjugated structure of PPy is as high as 74%. The PPy/CF-0 fiber and its reinforced composites showed negative coefficient of thermal expansion. The PPy-modification technology provides a new way of thinking for the design of composite materials by changing the surface roughness and negative thermal expansion coefficient, thus effectively enhancing the interfacial bonding performance and improving the thermal cycling stability of fiber-reinforced composites.

Objective Polyethylene (PE) nonwovens have excellent characteristics such as softness, corrosion resistance and hydrophobicity, and have broad application prospects in medical packaging, clothing, filtration and other fields. However, the traditional preparation process of high-performance polyethylene nonwovens is cumbersome, and the production process involves a large number of toxic solvents, and the production efficiency is low. Exploring the efficient preparation process of ultrafine polyethylene nonwovens has become an urgent research problem to be solved. Melt-blown technology is a common and efficient preparation method for microfiber, and the preparation of polyethylene microfiber by melt-blown method is rarely reported.

Method The preparation of low-density polyethylene(LDPE) melt-blown nonwovens was achieved by using a self-assembled melt-blown testing machine. The effects of different processes on the diameter of LDPE fibers were studied by controlling a single variable and adjusting the melt-blown process parameters in the experiment, including hot air temperature, hot air flow, mold temperature, melt flow and receiving distance. In addition, the filtration efficiency and tensile properties of LDPE melt-blown nonwovens were also studied.

Results The effects of melt-blown process parameters on the diameter of LDPE fibers were studied, including different hot air temperature, hot air flow rate, die temperature, receiving distance and melt flow rate. The results showed that increasing the hot air temperature, hot air flow rate and die temperature would reduce the average diameter of the fiber, and the average diameter of the fiber would increase after increasing the receiving distanc and melt flow rate. The minimum average diameter of the prepared fibers reached 5.3 μm, offering reference value for further preparation of polyethylene microfibers. The filtration performance of LDPE melt-blown nonwovens with different areal densities was explored, and the effect of areal density on LDPE filtration efficiency and filtration resistance was established, with the increase of areal density, the filtration efficiency and filtration resistance of melt-blown nonwovens showed a gradual upward trend. The filtration resistance was increased from 5.1 Pa to 20.9 Pa, and the filtration efficiency increased from 52.89% to 59.32%. After hot pressing treatment, the filtration efficiency of the 120 g/m² nonwoven fabric reached more than 75% at a flow rate of 32 L/min, and the average filtration resistance is 80 Pa. The mechanical properties of LDPE melt-blown nonwovens with areal densities of 25 g/m², 50 g/m² and 120 g/m² were investigated. The nonwovens with higher areal density were found to withstand greater tensile strength, and when the areal density is 25 g/m², the LDPE melt-blown nonwovens demonstrated the highest elongation at break, up to 75%. When the areal density was 120 g/m², the maximum pulling force and tensile strength of melt-blown nonwovens were the highest, reaching 6.12 N and 2.16 MPa, respectively.

Conclusion The melt-blown process can realize the efficient preparation of LDPE nonwovens, and the average diameter of the fiber decreases with the increase in hot air temperature, hot air flow rate and die temperature, and increases with the increase of receiving distance and melt flow, and the filtration efficiency, filtration resistance and tensile strength of melt-blown membrane increase with the increase of surface density of nonwoven. Process parameters would affect the microstructure and pore morphology of the fiber membrane, resulting in changes in mechanical properties and filtration properties. Furthermore, the microstructure of the melt-blown nonwoven can be changed by post-treatment processes such as hot pressing, and products with better performance can be obtained. So as to enhance the market potential and application value of polyethylene melt-blown nonwovens in the field of medical protection.

Objective Machine-harvested seed cotton always undergoes compression and baling procedure to augment fiber packing density and diminish volume, thereby enhancing the efficiency of cotton transportation and storage. However, determining an optimal range for compression parameters, then ensuring minimal damage to the cottonseed and maximal preservation of cotton fiber quality, holds significant importance for cotton production. Therefore, it is imperative to investigate the morphology of the compressed cottonseed and the cotton fiber quality.

Method To determine the primary and secondary relationship and the influence law of the compression parameters on the seed cotton quality, this study took the moisture content, trash content and compression density as the factors, and the cotton seed crushing rate, fiber length, micronaire value, elongation, reflectance (Rd), yellowness (+b), uniformity, and fiber strength as the indexes. Machine-harvested seed cotton was obtained through the cotton picking performance test, the cotton was compressed through the compression equipment, and the compressed cottonseeds and cotton fibers were obtained through ginning. The compressed cottonseed was chemically defluffed and dried to obtain the polished cottonseed, which was observed and screened with a microscope to obtain the cottonseed crushing rate; the compressed cotton fiber was sent to the testing laboratory to obtain the cotton fiber quality test results.

Results The results of variance analysis indicate that the order of the affecting factors of the crushing rate of cottonseed after compression is compression density, moisture content, and trash content. The order for fiber length is trash content, moisture content, and compression density. The order for micronaire value is moisture content, trash content, and compression density. The order for the elongation was moisture content, trash content, and compression density. The order for reflectivity was moisture content, trash content, and compression density. The order for yellowness was trash content, moisture content, and compression density. The order for uniformity was trash content, compression density, and moisture content. The order for fiber strength was compression density, trash content, and moisture content. The effect of moisture content, trash content, and compression density on cotton seed crushing rate was significant (P<0.05). The cotton seed crushing rate increased with increasing compression density, and decreased with in-creasing moisture content at a higher compression density. Trash content had no significant effect (P>0.05) on uniformity, fiber strength, elongation, reflectance. And compression density only had a significant effect (P<0.05) on cottonseed crushing rate and reflectance. Fiber length increased with increasing compression density and increasing moisture content, but decreased with increasing trash content. The micronaire value increased with the increase of trash content, decreased with the increase of compression density, and increased with the increase of moisture content. Elongation increased with increasing trash content, decreased with increasing compression density, and decreased slowly with increasing moisture content. The reflection rate increased with increasing compression density and decreased with increasing moisture content. The cottonseed crushing rate is the smallest when the moisture content is 14%, the trash content is 16%, and the compression density is 200 kg/m³. The maximum fiber length is obtained when the moisture content is 14%, the trash content is 8% and the compression density is 400 kg/m³. The elongation is minimized when the moisture content is 14%, the trash content is 8%, and the compression density is 400 kg/m³. The reflectance is minimized when the moisture content is 14%, the trash content is 8%, and the compression density is 200 kg/m³. The minimum yellowness is obtained when the moisture content is 6%, the trash content is 16%, and the compression density is 200 kg/m³. The micronaire value is between 4.50 and 4.90, which is at the standard level.

Conclusion Finally, we obtained that under the premise of ensuring higher compression density, increasing moisture content and trash content can ensure a smaller cotton seed crushing rate, while increasing moisture content will lead to a decrease in elongation, and increasing trash content will reduce fiber length and increase reflectivity. The research results have certain theoretical value for the determination of the working conditions of cotton picker and the design and selection of the parameters of compression molding device of cotton picker.

Objective With the proposal of the "double carbon economy" policy, green environmental protection and sustainable development become the direction of future textile development, and Xitu it is of great significance to develop new natural plant fibers and promote the application of natural banana stem fibers in the field of textile and clothing.

Method The semi-worsted spinning process was adopted with banana stem fiber (BF), EcoCosy^R antibacterial fibers (ATB) and rare earth antibacterial regenerated cellulose fiber (XT) as raw materials. Eight types of BF/antibacterial fibers (ATB and XT) blended yarns, with blending ratio of 50/50, 65/35, 70/30 and 85/15, and one BF pure spun yarn were prepared. The yarn density and twist were characterized, and the relationship between the blending ratio and mechanical properties, quality index and antibacterial properties of the yarn was investigated.

Results The measured linear density and twist of the 9 types of yarns were different from the designed values, but the deviation was within the tolerance range. The mechanical properties of BF pure spinning are poor, with the breaking strength being (7.12±1.45) cN/tex, the elongation at break (2.56±0.43)%, and the initial modulus (247.11±81.07) cN/tex. The mechanical properties of yarns were improved with the addition of ATB and XT content. The elongation at break of BF/ATB(50/50) and BF/XT(50/50) yarns was the highest, which was (4.19±0.46)% and (4.74±0.41)%. The breaking strength of BF/ATB(85/15) and BF/XT(70/30) yarns is the highest, and they were (9.33±1.45) cN/tex and (8.97±1.28) cN/tex respectively. With the increase of the content of ATB and XT, the defects such as knots, thick knots and detail of the yarn were greatly reduced, and the evenness of yarn strip and hairiness index were improved. The yarn unevenness was decreased from 21.83% to 13.91% and 14.8% respectively, and the hair index was decreased from 6.72 mm to 5.85 mm and 5.27 mm respectively, decreasing by 13% and 22%. The bacteriostatic rate of BF pure spinning against Escherichia coli was 65.47%, and the bacteriostatic rate of yarn increased with the increase of ATB and XT content. When the ratio of BF/ATB and BF/XT blended yarn was 50/50, the inhibition rate of Escherichia coli reached the maximum, which were 88.79% and 84.76% respectively, while for Staphylococcus aureus, the content of ATB and XT had little effect on the inhibition rate, and the inhibition rate of BF pure spun yarn and blended yarn could reach more than 95%.

Conclusion The addition of ATB and XT improved the mechanical properties and antibacterial properties of BF pure spinning. In addition, it also improves the quality indexes of BF pure spun yarn, such as strip evenness, hairiness index, knots, thick knots and details, making the blended yarn have higher breaking strength, excellent antibacterial property. It is of great significance for its application and development in clothing, and is suitable for the development of leisure woven shirt fabric and knitted fabric.

Objective Auxetic components can be used to create functional auxetic composite materials. The helical auxetic yarn (HAY) belongs to the group of auxetic reinforcement materials. Traditional auxetic yarns, made from filaments with a helical structure, often face issues like component slippage that can reduce yarn stability. They also lack the natural crimp and soft texture of staple fibers, which restricts their surface properties and applications. To address these challenges, this paper presents an innovative production method for helical auxetic yarns that incorporates staple fibers into the spiral wrapping structure. The aim is to enhance the yarn's auxetic performance and expand its range of applications.

Method Composite yarn was spun on a modified ring spinning machine to create a helical auxetic yarn based on the wrapping structure, with cotton and polyester filaments wrapped around a spandex filament. Besides, the double-filament helical auxetic yarn without cotton was also produced. The auxetic performance characteristics of these two types of yarns were analyzed and compared. Based on the spinning parameters, the effect of the yarn construction parameters on the negative Poisson's ratio was further investigated.

Results In this study, the negative Poisson's ratio of the new developed three-component and conventional two-component helical auxetic yarns was compared and analyzed. The maximum negative Poisson's ratios of the two yarns were similar, both less than -2, and the negative Poisson's ratio of two-component yarn was slightly better. In addition, the three-component helical auxetic yarn achieved a maximum negative Poisson's ratio at less strain compared with two-component yarn. Furthermore, after achieving the best negative Poisson's ratio, the Poisson's ratio of the three-component helical auxetic yarn was maintained below -0.5 with a tensile strain of 5% to 15%. However, after the two-component yarn reached the maximum negative Poisson's ratio, the negative Poisson's ratio effect of the yarn showed the weaking tread, flattening and approaching zero after 13% tensile strain. The influence of structural parameters of the helical auxetic yarn on the negative Poisson's ratio effect was discussed based on the spinning process parameters. Firstly, at a twist factor of 325, i.e., a helix angle of 27.4°, the negative Poisson's ratio effect was most obvious and its peak is at a 3% tensile strain. As the yarn twist factor increased, the negative Poisson's ratio effect diminished and larger tensile strain was required for reaching the maximum negative Poisson's ratio. Secondly, when the draft ratio of the wrapping filament was higher, the maximum negative Poisson's ratio of the helical auxetic yarn was initially increased and then decreased. When the draft ratio of the wrapped filament was 1.03, the negative Poisson's ratio was -3.24 which was the highest value among all the types of yarns. Thirdly, the draft ratio of the elastic core filament has negative effect on the maximum negative Poisson's ratio of the yarn. When the draft ratio of elastic core filament was 1.01 and 1.02, the negative Poisson's ratio of helical auxetic yarn was the best and similar, both less than -3.

Conclusion The enhancement of ring spinning machinery has facilitated the fabrication of a three-component auxetic yarn incorporating cotton fibers, thereby introducing an innovative approach to the design of auxetic yarns. The spinning process parameters, encompassing the twist factor as well as the drafting ratios of the core filament and the wrapping filament, exert a pronounced influence on the auxetic performance of the yarn. A comparative analysis of the auxetic properties of yarns manufactured under varying process parameters has yielded critical insights for optimizing the production process. This has led to the development of yarns that exhibit superior and consistent auxetic characteristics, thereby expanding the horizons and potential applications of auxetic materials within the textile industry.

Objective Rotor spinning belongs to airflow spinning, the airflow in each spinning machine affects the movement of the fiber. The study and comparison of the accuracy and difference of the airflow field can provide reference for the improvement of the spinning mechanism, so as to improve the yarn quality. To investigate the accuracy and differences of airflow field produced in combing and trash removal zone of rotor spinning simulated by two-dimensional (2-D) and three-dimensional (3-D) model, the numerical simulation results of 3-D model is compared to that of 2-D model. It is expected to express the suitable application of numerical simulation in guidance of structure and parameters modification in rotor spinning.

Method COMSOL simulation software was used to build the 2-D and 3-D geometric models of the combing and trash removal area. The model included combing chamber, sliver entrance, debris removal area and fiber transport channel. Model Ⅰ was a 2-D model, and Model Ⅱ and Ⅲ were 3-D models with different wedge shape of fiber transport channel. The "frozen rotor" in COMSOL multiphysics simulation was a special "steady-state" study dedicated to calculation of the velocity, pressure, and turbulence fields of flow in rotating machinery. The rotation was analyzed by introducing centrifugal forces.

Results The numerical simulation results of 2-D and 3-D models were similar in general, but differed in some results. The velocity at the exit of the fiber transport channel of 3-D model was higher than that of 2-D model, therefore, velocity distribution of 3-D model indicated a better improvement of fiber straightness. The energy of the turbulent flow in the 2-D model was basically below 10 J. The airflow is relatively stable, and only two large turbulent flow were generated near the entrance wall. In Model II, the turbulent flow was floated at the air filler due to a vortex, but it gradually became smaller as the cross section of the fiber transport channel got smaller, and the airflow was slowly stablized. The airflow stability in Model Ⅲ was obviously poor with many vortices, and the turbulent flow changed greatly. The velocity, pressure and turbulent energy distribution associated with the 3-D model was slightly more uniform than that of 2-D model, and the airflow and turbulent energy distribution in the trash removal area with the 3-D model was more accurate than that of 2-D model.

Conclusion The variation in velocity and pressure gradient at the outlet of the fiber transport channel of 3-D model is significantly larger than that of 2-D model. The airflow velocity, pressure and turbulent kinetic energy distribution in the lower half of the carding chamber of 3-D model is more uniform than that of 2-D model. The turbulent kinetic energy at the junction of the carding chamber and the debris removal area of three models illustrated large fluctuations due to intersection of airflow, but the airflow direction distribution demonstrated by 2-D model is not conducive to the exclusion of impurities with small volume and mass. Although there is a low-speed vortex in the trash removal area of 3-D model, there is airflow to the trash removal port, which is conducive to the exclusion of impurities. The wedge symmetric Model II has a slightly higher exit velocity maximum in the fiber transport channel than Model III, and the gradient change of pressure is more obvious and the turbulent kinetic energy change area is small. The movement of impurity particles in the 3-D models are better than that in the 2-D model, most of the impurity particles will be eliminated in time with the movement of the airflow, and only a small portion of the impurities will enter the fiber transport channel. Therefore, the geometric structure of wedge symmetric 3-D model II has better carding and separating effect on fiber bundles, which is beneficial to transfer of single fibers and straightening of hooked fibers. By comparison, the 2-D model simulation lacks accuracy besides small computational time and easy operation. The simulation results of the 3-D model are better than those of the 2-D model, and the 3-D model can show the numerical results on different levels, and the simulation of the details of the flow field and particle distribution is more accurate and intuitive, which is suitable for guiding the actual production and optimising the design of the rotor spinning mechanism.

Objective Traditional anti-slip chains have drawbacks such as bulkiness, loud noise, and susceptibility to tire damage, which can cause damage to the vehicle, discomfort to passengers and other inconvenience during use. An initiative product which can overcome these shortcomings is urgently needed to improve the anti-slipping performance of vehicles. This research aims to develop a new type of tire chains with advantage of lightweight, low damage to vehicles, low noise and comfortable to passengers.

Method A new cloth-made tire anti-slipping chain based on three dimensional (3-D) orthogonal woven fabric structure was proposed in this research. Ultra-high molecular weight polyethylene (UHMWPE)fiber was used to supply high wear resistance of the tire chain. UHMWPE fiber is a high-performance organic fiber with the best wear resistance Although the friction coefficient of UHMWPE fiber is small, through the conversion of dry and wet friction and the design of the concave-convex shape of the fabric surface, the anti-slipping sleeves show good anti-slipping performance in the test. Therefore, the UHMWPE fiber can effectively improve the wear resistance of the tire anti-slipping sleeves without affecting its anti-slipping performance. High moisture absorption fiber Ramie was selected to absorb the water film on the snow or ice road, transforming the wetting friction to dry friction between the tire and snow road. The UHMWPE fiber and ramie were hybridized in making 3-D woven structure to provide the tire chain with excellent anti-slipping and wear resistance. 3-D woven fabrics with different hybrid structures were prepared to determine the optimal parameters.

Results When the car is in motion, the water absorbed by the fibers is thrown out due to centrifugal force, forming a complete anti-slip mechanism. 3-D woven structure fabric would satisfy the requirement of high strength and wear resistance to tire chain. Because the ramie fiber would absorb partial water in the road, the braking distance of vehicle was decreased by 20.5% when equipped with UHMWPE fiber/ramie anti-slipping chain. The friction coefficient of UHMWPE fiber/ramie cloth chain was found 116% higher than current commercial product. The moisture absorption ability of fabric plays a significant role in its anti-slipping performance. Due to the highest volume fraction of introduced ramie fiber, fabric with interlayer spacer structure shows higher moisture absorption compared to the other two structures. Under the state of spinning and throwing water, the moisture absorption rate was 3.4%, 2.6% and 2.4% for interlayer spacer structure, inner-layer spacer structure and sandwich structure, respectively. The surface of the fabric is ultra high molecular weight polyethylene, which has a certain barrier effect on water. Subsequently, interlayer spacer structure presents the highest fabric friction coefficient, which is 12.4% and 150.8% larger than the inner-layer and sandwich structure, respectively. In addition, the more introduction of ramie fiber in interlayer spacer fabric formed a tighter fabric structure. This increases the binding force between the yarns,weaving resistance,and provides higher wear-resistance to the fabric. Three hybrid woven fabric structure all shows desirable dehydration property.

Conclusion Adding moisture absorbing fiber can absorb water film on the snow or road, which can gradually transform wet friction into dry friction, and improving tire anti slip performance. The wear-resistance of the fabric can be improved by reasonably designing the hybrid structure of UHMWPE fiber/ramie. The actual road test verifies the desirable anti-slip performance of fabric prepared in this manuscript. However, the wear resistance of the anti-slip fabric still needs further testing. The results of this research provide a new method of wire anti-slip mechanism with higher anti-slip performance. which have important practical value.

Objective The electrode of the sensor is placed in the external environment, and the surface conductive material is prone to oxidation and spalling to a certain extent during long-term use, thus affecting the performance of the sensor. Moreover, the air permeability of the packaging material is poor, which reduces the comfort of the human body. Knitting technology can knit conductive yarn into fabric structures, playing a role in improving the comprehensive performance of the sensor. This paper proposes a knitted capacitance sensor with integrated surface insulating electrode and dielectric layer.

Method The sensor electrode was designed by double-yarn knitting technology, and cotton yarn and silver-plated yarn were selected for knitting. The cotton yarn always covered on the surface of the silver-coated yarn, so that the electrode was placed inside the sensor, avoiding direct contact with the external environment. Nylon monofilament was used to knit dielectric layer, which was combined with fabric electrode to form capacitive sensor. The spacer fabric capacitive sensor was further placed in the middle of the indenter of the Mark-10 tension/compression meter. A conductive yarn was drawn from each of the upper and lower fabric surfaces of the sensor to connect the positive and negative collets of the precision LCR digital bridge TH2830, making it a complete conductive path. During the test, the digital bridge monitors and recorded the capacitance change of the sensor in real time. By analyzing the relationship between capacitance and pressure, the influence of different spacer fabric thickness and spacer wire diameter on the sensor performance was investigated.

Results The mechanical properties, insulation properties, sensitivity, hysteresis, response time and repeatability of the sensor were studied and analyzed. With the increase of thickness, the pressure required to achieve the same strain decreases, and the fabric was more easily compressed. The surface insulation performance of the sensor was further characterized. When the electrode pen was placed in the inner layer of the spacer fabric, the digital multimeter would detect the resistance value, indicating that the surface layer was conductive and acted as the electrode layer of the sensor. However, when the electrode pen is placed on the fabric surface layer, the multimeter would not read the resistance value of the fabric surface correctly. During the whole compression process, sensitivity showed different values in different compression strain ranges. The general trend was that as the compressive stress of the fabric increased, the capacitance change rate of the sensor was positively correlated with it. As the thickness of the spacer fabric increased, the sensitivity of the sensor increased gradually. According to the hysteresis error calculation principle, the maximum hysteresis error occurred at the stress of 6.49 kPa, and the value is 2.24%. The response time curve of the sensor showed that the response time was less than 150 ms. From the the trend of capacitance change rate with time during 2 000 cycles, it can be seen that the sensor maintained stable input and output electrical characteristics during the initial compression stage. To further verify its practical application value in the real application scenario, the capacitive sensor designed was used for the monitoring and recognition of hand movements. Based on the curve peak characteristics, the sensor was able to easily distinguish fingertip press and boxing movements.

Conclusion It is found that the sensor with larger thickness and smaller diameter of spacer wire has better overall performance, in which the sensor with thickness of 8.0 mm and spacer wire diameter of 0.15 mm has the best performance with sensitivity being 0.033 kPa^-1. Moreover, it has low hysteresis and fast response time, good resolution and response ability to input signals of different properties (different compression distances and different compression frequencies), and repeated stability within 2 000 cycles, showing good pressure sensing ability in hand motion recognition and liquid weighing scenarios. The sensor reduces the production cost, and the signal is stable during the application process, showing great application potential in wearable, medical monitoring and human-computer interaction interface.

Objective Deep learning models have poor generalization performance when faced with cross-scene fabric defect detection, and there is relatively little research on dynamic cross scene transfer methods. Due to the influence of camera type, parameters, environmental lighting and other image acquisition conditions, there are significant differences in the distribution of fabric image data. How to accurately extract target domain data under various imaging conditions and achieve effective detection of fabric defects across scenes is an urgent problem to be solved. To this end, a hybrid algorithm based on the Beetle global search algorithm(BAS) was constructed by adding local search capabilities to the global search capability of BAS to tackle the complexity and diversity in fabric images during fabric defect detection.

Method This research constructed a hybrid algorithm based on the Beetle algorithm by adding local search capabilities to the global search capability of BAS. Gabor filters were used to select the optimal parameters and establish a fabric detection scheme. In order to solve the optimization problem of the Beetle algorithm, local search capability was added to the global search capability of BAS. In order to obtain accurate binarization detection results, the image underwent threshold segmentation based on the use of low-pass filtering to convolution the results again.

Results In order to verify the effectiveness of the BAS model, the method proposed in this paper was compared with the methods in references. It was seen that the accuracy curve of this method was improved fastest and took the shortest time to reach the maximum accuracy, but the loss function curve fluctuated greatly. To verify the accuracy of the proposed method, the T-SNE method was used to visualize the features of fabric defects using the improved BAS method and the methods used in references. The method in this article showed a smaller distance in the embedding space, but the feature similarity extracted from defects and hole defects at the edge of the image was higher. To verify whether the proposed method extracted the features of defects, the Grad CAM method was used to visualize the defect features extracted by the model. The focus of this method was more concentrated within the range of fabric defects, and it was less affected by the background area. This verified that this method could effectively identify defect areas and has good generalization performance for cross-scene fabric defect detection. The optimal Gabor filter was used for fabric defect detection, and the defect detection effect of the proposed algorithm was evaluated in the form of binary images. The results show that the fabric defects detected by this algorithm are clear and accurate.

Conclusion The loss function curve of the method in this paper converge quickly, and the accuracy curve convergence value is high. The space for extracting all defect features of defects is closer, and the distance between each defect is larger. This proves that the features extracted from fabric defects in this paper are classified differently, and are less affected by the background. It verifies that the method in this paper can effectively identify the defect area with good generalization performance for cross-scene fabric defect detection. In practical applications, obtaining fabric images is influenced by lighting and fabric texture, which can affect the applicability of the model across-scenes, such as camera angle, fabric type, and camera parameters. The next step is to conduct research on other influencing factors such as camera angle and fabric type to further improve the model's generalization ability across scenes.

Objective Due to their snug fit, versatile fabric functionalities and other characteristics, seamless warp-knitted products are gaining gradual applications across various fields such as apparel, healthcare, and interior decoration. With the improvement of computer-assisted technology, the demand for online design and real-time simulation of seamless fabrics is becoming increasingly significant. This research mainly explores the knitting principle of seamless warp-knitted fabrics, discusses the special loop structure at the welt stitch locations, and focuses on the simulation research of simple seamless fabrics with double welt stitches.

Method Based on the principle of welt knitting in weft-knitted fabrics, the structure of double-layer welt was analyzed, and a knitting diagram model was established. To deal with the opposite directions of double-layer loops, a top-down grid division and a bottom-up grid division were proposed, and the corresponding loop grid model was established based on the relationship between model points and grid points. Combining the corresponding yarn parameters in the threading model, the three-dimensional loop structure was drawn using WebGL technology.

Results Based on an in-depth study of the loop structure of weft-knitted tubular seamless products a loop geometric model, an upper tuck loop geometric model and a lower welt loop geometric model have been established based on the classic Pierce loop model and the actual shape of the loops. Considering the unique double-layer loop structure of the welt in weft-knitted tubular seamless products two loop mesh models of the same size but opposite directions and a welt loop mesh model were constructed. By combining the loop geometric models, the mathematical relationship between the type value points and the mesh points was constructed to obtain the loop mesh parameters, and the z-direction of the special transverse row loop type value points was adjusted.

An upper welt knitting pattern model, a garment body knitting pattern model, and a lower welt knitting pattern model were established. Through the process, the corresponding loop mesh model was determined using an algorithm, where the direction of loops in the front half of the lower welt and the back half of the upper welt runs from top to bottom, utilizing the welt loop mesh model. For the garment body and the back half of the lower welt and the front half of the upper tuck, the direction of loops runs from bottom to top, using the gridf loop mesh model. By integrating the yarn parameters from the threading model, the three-dimensional loop structure was rendered using WebGL technology.

Examples were presented to demonstrate the simulation effects of typical weft-knitted seamless products in both tubular and flat unfolded forms, clearly showing the interlocking relationship of loops and the double-layer structure characteristics at the welt stitch areas. Examples also showcased the effect of the garment on a human body, with the simulation image of a tube top closely fitting the surface curves of the body, hiding the back welt stitch structure in a way consistent with the actual fabric.

Conclusion The implementation of three-dimensional simulation for seamless warp-knitted products bypasses processes such as machine trials, directly obtaining the finished fabric effect from the pattern design, reducing product development steps, and improving product development efficiency. By comparing the simulation results with the actual fabric, it is demonstrated that using this method to simulate seamless warp-knitted products with double welt stitches is scientifically feasible. It can perform three-dimensional planar, cylindrical, and curved simulations for simple seamless warp-knitted tube tops, laying a foundation for further research into the simulation of complex seamless warp-knitted products.

Objective Textiles are widely used in the field of acoustic absorption due to their porous texture, lightweight and formability. Due to the viscous inertia and thermal dissipation mechanisms in acoustic absorption of textile materials, the Johnson-Champoux-Allard(JCA) acoustic model is believed suitable for characterization their acoustic property. However, few studies were conducted on the acquisition of acoustic parameters in JCA model and the relations between acoustic parameters and fabric structure remains vague. This paper proposes a method to quickly acquire JCA acoustic model parameters and predict the acoustic absorption of weft-knitted knitted fabric. The particle swarm algorithm was chosen to obtain the JCA acoustic model parameters by inverse analysis. The relations between fabric structure and acoustic parameters were explored, and the sound absorption coefficients of knitted fabrics with different structures were predicted.

Method Particle swarm algorithm was chosen to inversely analyze the acoustic absorption coefficient of weft-knitted fabrics, to obtain parameters of JCA acoustic model, including porosity, flow resistance, tortuosity, viscous characteristic length and thermal characteristic length. By adding inertia weights and learning factors, the inverse analysis process was restricted, thus reducing the number of iterations, avoiding the local optimal solutions, and improving the accuracy of the parameters obtained from the inverse analysis. Based on the results of the inverse analysis, the relations between the structural parameters of the weft-knitted fabric (unfilled coefficient) and the structural parameters of the JCA acoustic model (porosity, flow resistance) were established, and the JCA acoustic model parameters of knitted fabrics with different structures were obtained quickly for acoustic absorption coefficient calculation. The accuracy of the obtained JCA acoustic parameters of fabrics with different structures was verified by the finite element method.

Results The acoustic parameters such as porosity, flow resistance, tortuosity, viscous characteristic length and thermal characteristic length were inversely analyzed by the particle swarm algorithm. After 100 iterations, the iteration speed slowed down and gradually stabilized, reaching the globally optimal solution. The final iteration number was less than 200, with a minimum value of 0.19. Comparison of the numerically calculated sound absorption coefficient with the experimentally measured curves showed that the particle swarm algorithm was able to accurately inverse-analyze the JCA acoustic parameters in the range of 500-5 000 Hz. When the structure was changed, the material parameters, including tortuosity, viscous characteristic length and thermal characteristic length, were empirically obtained from the inverse analysis. Porosity was determined by the unfilled factor according to the global optimal solution. Flow resistance was obtained by fitting the porosity and the flow resistance using the exponential function in the least squares method with known inverse analytical parameters. The coefficient of determination R² was 0.994 6, indicating the effective fitting. The accuracy of JCA acoustic parameters obtained by above method was verified by finite element method. The sound absorption coefficient curves obtained from the finite element calculations for the weft flat-needle tissues fitted well with the inverse analysis and experiments. The coefficient of determination R² was 0.809. The sound absorption coefficient curves obtained from finite element calculations of the double inverse organization fitted the inverse analysis and experiments well. The coefficient of determination R² was 0.852. The work proves the accuracy and reliability of the fabric structure parameters deduced from the JCA acoustic model.

Conclusion The particle swarm method was optimized to inversely analyzing the sound absorption coefficient of weft knitted acoustic-absorption material, and the number of iterations is less than 200, achieving the rapid acquisition of the parameters in the JCA acoustic model. For different textile structures, by directly obtaining the porosity and flow resistance coefficients and combining them with known material parameters, the sound absorption coefficients at different frequencies can be calculated quickly and with less error. This method provides new ideas for the acquisition of acoustic parameters and the prediction of sound absorption performance of acoustic-absorbing material.

Objective In the general trend of the development of flexible protective equipment, people have higher and higher requirements for protective clothing, flexible puncture-proof material requiring protective materials to be able to simultaneously achieve light weight, good protective effect, and to enhance comfort. High-performance fiber materials are lightweight and textile processable. However, when multiple layers of textiles are stacked up to achieve puncture-proof performance, the final product materials show heavyweight and poor wearing comfort. While high-performance fabric composites effectively improve the puncture resistance, this study aims to improve the puncture resistance of high-performance fabric composites and to investigate the application of composites.

Method Multiphase shear thickening fluids (MSTFs) were prepared by dispersing monodisperse phase SiO₂ particles in polyethylene glycol (PEG) 200 and adding multi-walled carbon nanotubes (MWCNTs). The shear thickening solution was stored under open exposure, sealed exposure and sealed from light, and the ageing properties of the shear thickening solution were investigated based on the rheological properties. After that, the aramid fabric was impregnated with MSTFs (S), and multilayer composites with different stack structures were prepared by combining silicon carbide/polyurethane (SiC/TPU) coated aramid fabric (T) and untreated aramid fabric (N), and quasi-static stapling and dynamic knife-puncture behaviors were investigated.

Results The study investigated the effect of interfacial interaction on the puncture resistance of the composites. It was found that the critical shear rate of MSTFs with the addition of multi-walled carbon nanotubes decreased, the maximum thickening viscosity was increased, and the thickening effect was improved. In this circumstance, the rheological properties of the shear-thickened solution under open exposure storage conditions were decreased more in a short period of time and were easily affected by air humidity. Due to the better water absorption of PEG, indicating decreased number of hydrogen bonds between PEG and silica and after moisture absorption, the viscosity of the system was decreased, and the interaction force between the particles was enhanced, hence not easy to produce more particle clusters. Regression analysis was performed with storage time as the variable thickening rate as the dependent variable, and it showed that y_STF=31.695xSTF-0.278 and y_MSTFs=29.115xMSTFs-0.262, with a strong correlation between the variables. In addition, from the results of quasi-static nail testing, it was clear that the three-layer composite prepared by shear-thickening solution impregnating aramid fabric (S) + pure aramid fabric (N) + coated aramid fabric (T) laminate structure exhibited the best puncture resistance, and the SSNNTT laminate structure illustrated better puncture-proof performance than the six-layer composite with SNTSNT laminate structure. Due to the friction between long spike and MSTFs-impregnated fabrics increased, and the MSTFs composite fabric can be bonded with pure fabric to more tightly to limit the slip of pure fabric yarns and fibers, which driving more yarns to resist puncture. Therefore, when the long nails wrapped around the fabric pierced the coated fabric, it need for greater puncture force to pierce the coated fabric, the number of yarn and fiber breaks at the puncture opening increased, the anti-puncture performance is improved. while in SSNNTT laminated structure, the friction between double-layer MSTFs composite and long spike is greater, and the sandwiched pure fabric has more yarns involved in the puncture process, thus absorbing more puncture energy. According to the change curve of impact force and impact energy corresponding to the puncture process. The dynamic puncture performance of the composites is consistent with their performance in static puncture resistance behavior, with the 5S5N5T(S N T with 5layers each) structural composites providing the best knife puncture resistance. During the piercing of the tool, the impact force of the instant composite material punctured by the knife tip reaches the maximum, and the impact energy of the tool is rapidly reduced at this time. So the consumption of impact energy by puncture-resistant materials is mainly concentrated in the puncture process before the impact force reaches its maximum value, and it shows that the impact energy of multi-layer composite decreases more than that of the tool before the material is punctured, which exhibits better anti-stabbing performance. From the duration of the energy begins to drop to the minimum impact energy, the duration of the multi-layer composite is longer than that of the multi-layer pure fabric, indicating that the multi-layer composite has more resistance to impact energy. However, the pure fabric deforms more during the puncture process and can play a certain role in buffering, while the composite material is strong and can play the strength advantage of high-performance materials faster, absorbing energy faster and showing better protection performance.

Conclusion In the study, the isolation of moisture can effectively maintain the rheological properties of the shear thickening solution and the anti-stab performance of its composites, and the design of the laminated structure of different anti-stab composites can maximize the anti-stab performance of the multilayer composites due to the effect of interfacial friction. And take advantage of the performance of different materials to realize the synergy of materials to reduce the weight of composite materials to improve the anti-stabbing performance, and provide a theoretical research basis for the structural design of anti-stabbing layer materials for anti-stabbing clothing.

Objective It is well known that natural starch exhibits insufficient adhesion to fibers and strong film brittleness, due to numerous hydroxyls and cyclic structure on its chains. As concluded, the alkyl carboxylate monoester groups introduced onto starch chains by chemical esterification can improve the properties of starch. The groups include acetate, propionate, butyrate, and caproate groups. However, the effect of the alkyl chain length of these alkyl carboxylic acid monoester substituents on the properties of starch has not been explained. Therefore, the main purpose of this study is to ascertain the effect of the alkyl chain length of these alkyl carboxylic acid monoester substituents on the properties, in order to identify the starch alkyl carboxylic acid monoester with the best sizing properties for polyester warp yarns.

Method To ascertain the effect of the alkyl chain length of these alkyl carboxylic acid monoester substituents on the sizing properties of starch, four types of starch alkyl carboxylic acid monoester samples with a similar degree of substitution of 0.018 were prepared by the esterification of acid-converted starch (ACS) with vinyl acetate, propionic anhydride, butyric anhydride, and caproic anhydride as esterifying agents, respectively, under the weakly alkaline and low-temperature conditions, in aqueous medium. The surface morphology of their granules was observed and analyzed by a scanning electron microscope, and the modification levels of starch alkyl carboxylic acid monoester samples were determined by titration analysis. The effects of the alkyl chain length of these alkyl carboxylic acid monoester substituents on the adhesion to polyester fibers, film properties, and apparent viscosity were investigated, and the adhesion was investigated by a standard method (FZ/T 15001—2008) in China via measuring the bonding force of slightly sized polyester roving. The measurement of film properties mainly contained tensile strength, breaking elongation, and bending endurance. The apparent viscosity was determined on an NDJ-79 rotary viscometer at a shear rate of 1 850 s^-1.

Results SEM results revealed that the starch samples were still in a granular state, but some damages were produced on granular surfaces, which was mainly attributed to the modifications occurred under alkaline conditions and at the free hydroxyls on the granular surfaces. The starch alkyl carboxylic acid monoester samples with an esterification level of about 0.018 were prepared, by the esterification of ACS with the 9 g of vinyl acetate, propionic anhydride, butyric anhydride, and caproic anhydride, respectively. The adhesion of the samples to polyester fibers and size film elongation and endurance were found higher than that of ACS. The introduction of alkyl carboxylic acid monoester substituents on the starch chains played an internal plasticization on the starch adhesive layers and films, promoting the bonding force to polyester roving and film elongation and endurance. Increasing the alkyl chain length of the alkyl carboxylic acid monoester substituents produces gradually increased bonding force, and film elongation and endurance. The tensile strength of the size films was reduced. The esterification modification with a low degree of substitution had no obvious effect on the apparent viscosity of the starch paste, making it still have good flowability and beneficial for the adhesion between starch and fibers.

Conclusion This study concluded that the esterification could improve the adhesion and film properties of starch, thereby favoring the promotion of its sizing quality to warp yarns. The alkyl chain length of the alkyl carboxylic acid monoester substituents showed an important correlation with the properties, and along with the rise in the length, the adhesion, and film elongation and endurance were gradually increased. It is identified that the use of caproate starch(CS) in polyester warp sizing leads to best sizing properties.

Objective Functionally modified polyester textiles with high added value have significant development value in the fields of both domestic and industrial textiles. Cationic dyeable modified polyester fabrics are often endowed with enhanced functionality by coating and cross-linking with polymers. However, these modifications can compromise their breathability and adversely affect their apparent color and luster. This study aims to synthesize a novel photo-functional benzo[a]phenoxazine cationic dye, aim to achieve an integrated construction of both color and functionality on cationic dyeable modified polyester fabrics via a streamlined dyeing process.

Method Two dyes, 5-ethylenediamino-9-(diethylamino)benzo[a]phenoxazine ammonium chloride (N1) and 5-propylamino-9-(diethylamino)benzo[a]phenoxazine ammonium chloride (N2), were synthesized via nucleophilic substitution reactions. The structural characterizations of these dyes were accomplished using proton nuclear magnetic resonance (¹H NMR) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. Additionally, 5-amino-9-(diethylamino)benzo[a]phenoxazine ammonium sulfate (Nile Blue sulfate, N3) was selected as the comparative dye. The photophysical and chemical properties of these dyes, along with their dyeing performance on cationic dyeable modified polyester fabrics, were investigated using a color matching instrument, UV-visible spectrophotometer, and fluorescence spectrophotometer. The fluorescence emission and photodynamic properties of the dyed fabrics were also examined.

Results This study was focused on two photo-functional benzo[a]phenoxazine cationic dyes for dyeing cationic dyeable modified polyester fabrics.¹H NMR and FT-IR confirmed the successful synthesis of 5-ethylenediamino-9-(diethylamino)benzo[a]phenoxazine ammonium chloride (N1) and 5-propylamino-9-(diethylamino)benzo[a]phenoxazine ammonium chloride (N2). The maximum absorption wavelengths (λ_max) of the three dyes in water were 648 nm, 639 nm, and 635 nm, respectively, presenting a blue color. In DMF, both λ_max and the maximum emission wavelengths (λ_em) of the three dyes exhibited a blue shift, with the solution color changing from blue to red and displaying orange-yellow fluorescence under a 365 nm ultraviolet lamp, which may be caused by the molecular deprotonation. Dye N2, with a propyl amino group at the 5-position, achieved a dye-uptake of 99.65% on cationic dyeable modified polyester fabric, demonstrating rapid dye uptake with good levelness. The a^*(green-red axis) and b^*(blue-yellow axis) values of the fabrics dyed with these dyes were all negative, while the lightness (L^*) values were positive, indicating that the dyed fabric exhibited a bright blue with a greenish tint. Due to the enhanced π-π^* transition caused by the propyl amino group in dye N2, fabric dyed with 1% (o.w.f) dosage exhibited strong red fluorescence, while the increasing dye dosage led to fluorescence self-quenching on the fabric. The photodynamic properties of the dyed fabrics were investigated. The bleaching rate of 1,3-diphenylisobenzofuran on fabric dyed with N3 (6%, o.w.f) reached over 80% after 40 min of red-light exposure. Under the same condition, the bleaching rate for fabric dyed with N1 was 63.5%, demonstrating that these dyed fabrics have the ability of photoinduced singlet oxygen generation. Additionally, color fastness tests indicated that the fabrics dyed with these three dyes (1%, o.w.f) achieved excellent rubbing and washing fastness which is over level 4, and the light fastness were in the range of levels 3 to 4.

Conclusion In this work, two benzo[a]phenoxazine-based functional dyes (N1 and N2) were developed and characterized. N1 and N2 exhibit solvatochromic behaviors, and they have excellent dyeing performance on cationic dyeable modified polyester fabrics with high dye-uptake rate and good color fastness. The dyed fabrics show red fluorescence emission and photodynamic¹O₂ generation ability. Dye N1 with an ethylenediamine group at the 5-position has better photodynamic¹O₂ generation performance than the dye N2. This offers a novel approach to the development of multicolor textiles for health and safety protection. In future research on benzo[a]phenoxazine cationic dyes, further modulation of molecular structure could enhance the photodynamic generation of reactive oxygen species by the dyes and the antibacterial activity of the dyed fabrics, thereby enriching the color palette and functional versatility of health protection textiles.

Objective Polyester (PET) fabrics attracted much research attention in textile fields for its high yield and excellent performance. At present, a variety of methods have been developed to modify polyester fibers with antibacterial, flame retardant, electrostatic, and hydrophobic properties. In addition, hydrophobic modification of polyester fiber plays an important part in applications of medical treatment, filtration, separation, and sanitation. However, PET fabrics with many ester linkages are easily hydrophilic, and can be easily polluted, which seriously limits its applications in ocean envrionment. In order to solve the problem of poor hydrophobicity caused by polar ester groups in the main chain structure of polyester fiber, a fluorine modification strategy is proposed.

Method The simple and efficient hydrophobic modification of the surface of polyester fabrics was carried out by using alkaline solution as etching reagent and trichlorosilane (1H,1H,2H,2H-perfluorooctyl trichlorosilane) as fluoridation modification reagent. The chemical structure, melting point, thermal stability, contact angle, microstructure morphology, and element distribution on surface were characterized by infrared spectroscopy, differential scanning calorimeter, thermogravimetric analyzer, contact angle tester, and scanning electron microscopy-energy disperse spectroscopy, respectively. Moreover, the possible hydrophobic mechanism was analyzed, and the adsorption experiment of petroleum ether by polyester fabrics was also carried out.

Results The results showed that the polyester fabrics demonstrated similar chemical structure and melting point (around 250 ℃) before and after modification. The high thermal stability of polyester fiber before and after modification was beneficial for the adsorption of oil spill at high temperature. The fluorinated polyester fabrics were successfully modified by perfluorosilane, as evidenced by the increased presence of fluorine elements and silicon elements on the surface of the polyester fiber fabrics. In addition, due to the low surface energy of fluoro-silicon polymers, marine fouling organisms would be difficult to aggregate and would fall off the surface of fabrics easily. The maximum thermal decomposition temperature for all samples was found around 448 ℃ after thermogravimetic analysis. Water droplets were absorbed quickly prior to fluorine modification. The hydrophobicity of the fluorinated polyester fabrics was greatly improved, and the water contact angle was as high as (120±5)°. After 1 h of hydrophobicity treatment, the water contact angle was basically constant. Moreover, the hydrophobic mechanism of the fluorinated PET fabrics was revealed in detail. Firstly, perfluorosilane hydrolyzes in ethanol and a large amount of —OH is formed at the end. The polyester fabric after treated with alkaline solution exposes a large amount of —OH and —COOH. The hydrolyzed perfluorosilane works on the surface of the polyester fiber fabrics to form hydrogen bonds, and the small molecular water was removed under heating conditions. In this case, the modifiers containing fluoro-functional groups are chemically bonded onto the surface of polyester fiber fabrics to obtain fabrics with a low surface energy. The polyester fabrics possessed high adsorption capacity for organic solvents, and the adsorption capacity of polyester fabrics for petroleum ether was found to be 8 g/g within 1 min.

Conclusion The development of multifunctional PET fabrics with superhydrophobic properties is considered necessary and urgent. In response to this need, a simple and efficient hydrophobic modification method was conducted on polyester fabrics using an alkaline solution as an etching reagent and trichlorosilane (1H,1H,2H,2H-perfluorooctyl trichlorosilane) as a fluorinated modification reagent. This fluorination process resulted in a significant improvement in the hydrophobicity of PET fabrics, as evidenced by larger water contact angles. The research work conducted in this study provides insight into the mechanism of hydrophobic modification of polyester fabrics, which holds great significance for future studies in this field. In a word, the fluorosilane-coated PET fabrics exhibited several advantages, including a simple preparation process, low cost, and effective performance. Consequently, these fabrics have promising applications in large-scale production and utilization for multifunctional purposes such as antifouling and oil-water separation. Overall, the development of superhydrophobic PET fabrics through fluorosilane coating holds immense potential and offers various benefits for the textile industry.

Objective As a high-end fabric coating agent, water-based polyurethane holds vast development potential. In-depth research along this line will not only help improve the quality and performance of domestic coating products but also promote technological progress and innovative development in the textile coating industry. Compared to traditional solvent-based polyurethanes, water-based polyurethanes are more environmentally friendly, with lower VOC emissions, aligning with current green and sustainable trends. Additionally, the water-based polyurethanes can add more functionalities and value to textiles, enhancing the market competitiveness of products.

Method Using polyethylene glycol monomethyl ether (MPEG) and itaconic acid (IA) as the raw materials, itaconic acid polyethylene glycol monomethyl ether ester (IM) containing C=C double bonds was synthesized via esterification reaction, and IM was characterized using infrared spectroscopy and nuclear magnetic resonance spectroscopy. After mixing IM with hydroxyethyl methacrylate-terminated water-based polyurethane (HWPU), a water-based polyurethane fabric coating agent terminated with itaconic acid polyethylene glycol monomethyl ether ester (WPU-IM) through UV grafting was obtained. The properties of the WPU-IM film and fabric coating were analyzed using infrared spectroscopy, water absorption tests, tensile tests, hydrostatic pressure resistance tests, and water vapor transmission rate tests.

Results With the increase in the mass fraction of WPU-IM, the water absorption rate of the film rose from 6.8% to 17.9%, and the water contact angle was decreased from 90.4° to 78.1°, indicating an enhanced hydrophilicity of the film. Meanwhile, the water vapor permeability of the coated fabric rose on the increase in WPU-IM content, demonstrating that the introduction of polyethylene glycol segments can improve the moisture permeability of the waterborne polyurethane fabric coating agent. When the mass fraction of IM is 2.1%, the water vapor permeability of the fabric coating reached 4 086.3 g/(m²·d), consistent with the moisture permeability mechanism of hydrophilic non-porous membranes. When increasing the mass fraction of WPU-IM, the elongation at break of the film was gradually increased, reaching 325% when the mass fraction of IM is 2.1%, which indicated improved ductility of the film. However, the tensile strength of the film and the hydrostatic pressure resistance of the coated fabric demonstrated a decrease with the increase in the mass fraction of WPU-IM, with the tensile strength dropping from 12.63 MPa to 5.49 MPa and the hydrostatic pressure resistance decreasing from 27.12 kPa to 17.31 kPa.

Conclusion The synthesized WPU-IM, using IM as a biomass raw material and by introducing polyethylene glycol hydrophilic chain segments into the polyurethane chain through free radical polymerization, can effectively improve the moisture permeability of water-based polyurethane fabric coating agents and enhance the ductility of the coating film. However, it is also found that excessive introduction of WPU-IM is not conducive to the water resistance and mechanical strength of the fabric coating.

Objective Smart textiles are a new type of textile material that highly integrates flexible electronic devices with fabrics, which has great application potential in medical health and sports monitoring. The fabrication of flexible piezoresistive sensors, which enable the interaction between the human body and external information, is crucial for achieving smartness in textiles. Addressing the challenges posed by the intricate preparation process of flexible piezoresistive sensors and the integration of conductive materials with fabrics, this study presents a fabric-based approach to overcome these limitations.

Method Polydimethylsiloxane-multi-walled carbon nanotubes/carbon black (PDMS-MWCNTs/CB) was used as a conductive composite material for coating non-woven fabric, aiming to fabricate a piezoresistive layer. Microdrop injection technique was utilized to pattern fork-finger metal electrodes directly on the fabric surface, thereby facilitating the construction of flexible piezoresistive sensors based on fabric. Characterization and analysis of the fabric metal electrodes, conductive composites, piezoresistive layers, and sensors were carried out using an RTS-4 four-probe tester, field-emission scanning electron microscope, tensiometer, digital bridge, and a self-assembled cyclic recirculation device.

Results Conductive composites with different mass ratios of CB and MWCNTs were prepared, and the piezoresistive properties of the conductive composites with varying ratios of mass were investigated. The results showed that the resistance increment (R₀-R) of conductive composites tended to increase and then decrease with the increase of CB content under the same pressure. When the mass ratio was 3∶2, the conductive composites exhibited superior piezoresistive response characteristics. Conductive composites and pressure-sensitive layers, incorporating MWCNTs with varying filling contents, were fabricated and investigated. The study encompassed morphological examination of the conductive composites and microstructural analysis of the pressure-sensitive layers. The findings revealed that MWCNTs could be uniformly dispersed within PDMS, with a denser conductive network emerging as the filling quality increased. A synergistic conductive network, characterized by a "grape cluster"-like arrangement, was observed to interconnect MWCNTs and CB within the conductive network. The conductive composite material was uniformly deposited on both the surface and within the nonwoven fabric. Flexibility tests demonstrated that the conductive composite material could be securely adhered to the fabric, with no separation of the conductive material from the nonwoven base. Sensitivity quantifies the ability of the sensor to reflect external stimuli accurately. Sensors with varying MWCNT fillings were prepared and tested to assess sensitivity. The results revealed that the resistance change rate escalated with increasing pressure. The sensor exhibited its highest sensitivity of 0.353 kPa^-1 when the MWCNT filling mass fraction reached 2.5%. The comprehensive performance of the sensor was examined, focusing on aspects such as hysteresis, response/recovery time, repeatability stability, and resolution. The sensor, filled with 2.5% MWCNTs, demonstrated a hysteresis rate of approximately 31.2%, attributed to the inherent structure of the nonwoven material. Its response/recovery time was 150/200 ms, with a minimum detection limit of approximately 49 Pa and excellent repeatability stability (about 1 600 times). Furthermore, the responsiveness of the sensor to human motion signals, including pressure signals from finger presses and finger/wrist flexion, was tested. The results indicated that the sensor could detect and provide feedback on finger pressure, finger bending angle, and continuous wrist bending signals, rendering it suitable for applications in human health and motion signal monitoring.

Conclusion This research addresses the difficulty in achieving efficient integration between conductive materials and textiles. The textile-based flexible piezoresistive pressure sensors demonstrate superior sensing capabilities, rendering them appropriate for monitoring human motion signals. These sensors exhibit considerable potential for further development in applications related to human health and movement tracking. Enhanced sensing performance can be achieved by optimizing conductive composite preparation techniques and developing flexible sensors. This sensor may be further enhanced by exploring and incorporating additional fabric substrates.

Objective Superhydrophobic materials have a wide range of applications with their unique properties. However, the preparation often involves fluorine-containing materials, organic solvents, an so on, which are expensive and cause pollution, seriously limiting their applications. Therefore, it is important to develop environmentally friendly and low-cost materials to prepare superhydrophobic materials through simple preparation processes.

Method Porous carbon based on bagasse was prepared by high-temperature carbonization and activation. After pretreatment (80 ℃, drying for 12 h), bagasse was calcined at 650 ℃ for 20 min under N₂ flow to obtain carbonized bagasse (CB). Different proportions of CB and KOH were mixed and grinded, and the mixture was then heated in a nitrogen atmosphere to activate CB. The obtained black particles were washed with HCl and deionized water and dried at 80 ℃ to prepare bagasse-based porous carbon (BPC). The prepared BPC and low surface energy substance polydimethylsiloxane (PDMS) were applied to cotton fabric, which is a process known as BPC/PDMS treatment of cotton fabric.

Results The BPC was fabricated via a high-temperature carbonization method, achieving a remarkable specific surface area of 1 614.25 m²/g. Notably, the BPC-800 ℃ exhibited a high degree of graphitization with an I_D/I_G ratio of 0.76. When the activation temperature was set at 700 ℃ and the BPC to KOH ratio was 1∶4, the BPC surface displayed an optimal rough structure with an abundant microporous network. By employing a simple impregnation method, the prepared BPC and the low surface energy substance PDMS were coated onto the cotton fabric, resulting in the BPC/PDMS treatment of cotton fabric. The influence of varying BPC and PDMS concentrations on the hydrophobic properties of the finished fabric was investigated and the results revealed that the surface contact angle of the BPC/PDMS cotton fabric peaked at 162.2° when the PDMS concentration was 3% and the BPC concentration was 0.2%. The combination of BPC and PDMS imparted the fabric with a rough surface, crucial for achieving superhydrophobic properties. Additionally, due to the adhesive nature of PDMS, it was observed that the BPC particles were firmly encapsulated on the cotton fabric surface by PDMS, successfully constructing a superhydrophobic surface. The TGA curve revealed that when the temperature reached 700 ℃, the residual percentage of the BPC/PDMS treatment of cotton fabric was 16.59%, 40 times higher than that of untreated cotton fabric. This was primarily attributed to the incomplete decomposition of BPC and PDMS, confirming the successful preparation of the superhydrophobic cotton fabric. As a result, the BPC/PDMS treatment of cotton fabric exhibited water repellency and a "silver mirror" effect. The water contact angles of the untreated and BPC/PDMS cotton fabric were 0° and 162.2°, respectively. Furthermore, water, cola, juice, milk, and coffee droplets remained spherical on the surface of the BPC/PDMS treatment of cotton fabric, while they spread rapidly on the untreated fabric. These results indicate that the BPC/PDMS treatment of cotton fabric achieved remarkable water and stain repellency. When the fabric was placed onto a slide and positioned inclined, methyl blue and purple chalk powder were uniformly sprinkled on the fabric surface followed by rapid rolling water droplets. Notably, both the methyl blue and purple chalk powder were completely removed from the surface, leaving no trace of contaminants. This outstanding performance demonstrates the excellent self-cleaning capabilities of the superhydrophobic cotton fabric.

Conclusion The preparation of bagasse-based porous carbon (BPC) was thoroughly examined. Notably, when the activation temperature was set at 700 ℃ and the ratio of BPC to KOH was 1∶4, the resulting BPC achieved a significant specific surface area of 1 614.25 m²/g, along with a high degree of graphitization. Furthermore, its surface exhibited a coarse texture with a substantial micropore distribution. To impart superhydrophobicity to cotton fabric, BPC and polydimethylsiloxane (PDMS), a low surface energy material, were applied to the fabric. This combination of microscopic roughness and low surface energy materials is crucial for achieving superhydrophobicity. The successful loading of BPC and PDMS onto the cotton fabric was confirmed. When the PDMS concentration was set at 3% and the BPC concentration at 0.2%, the water droplet contact angle on the BPC/PDMS treatment of cotton fabric reached an impressive 162.2°, demonstrating excellent superhydrophobicity. Additionally, cola, water droplets, milk, and fruit juice remained spherical on the surface of the BPC/PDMS treatment of cotton fabric, indicating its remarkable self-cleaning, stain resistance, and water repellency properties.

Objective Under the background of digital economy, the popularity of individual needs promotes the diversified development of clothing styles, which brings new opportunities and challenges to clothing production. At present, the clothing market as a whole presents a "multi-variety, small batch, short cycle" production mode. In order to reduce production difficulty caused by excessive style changes and to reduce production costs, industrial customization is oriented to customer demand while taking into account the production speed and economic benefits, in which modular production is one of the effective means to achieve this production mode.

Method Using the fuzzy clustering of equivalence relation, the method of building module group of shirt processing components was achieved. The typical shirt styles produced in recent years were taken as the research object, the common styles in production were sorted and classified. The main shapes and processing methods were summarized, the processing modules and stitch types were classified and coded, and the shirt modules were divided under the production situation of short flow.

Results After the basic module group and processing technology are summarized, the classification of clothing modules is quantitatively analyzed and studied. First of all, the complex process is preliminarily screened. Processing examples of different modules : 0 indicates that the module does not use this process, 1 indicates that the module will use this process for processing. The truncated matrices under different λ thresholds are established by fuzzy hierarchical matrix. The modules are clustered from large to small, and different truncated matrices are divided into different truncated matrices. A total of 19 kinds of clustering results were obtained for all types of parts (parts) modules, with a total of 42 parts (parts). On the basis of preliminary screening, fuzzy F-statistic formula was used to calculate the corresponding values of different clustering results. The optimal solution is obtained when the module group of shirt production process is divided into 11 classes. According to the results of F-statistic quantitative analysis, the division of the final module group clustering results is obtained.The final clustering results are basically consistent with the actual production, and the module processing technology in the same module group is basically similar.

Conclusion The theoretical method of this research is extended to cost accounting, wage payment, quality assessment and other aspects, and provides certain reference value for the production of clothing production arrangement, construction period forecast and other production links. In the following research, we will focus on the research direction of module family time prediction based on BP neural network and the optimization application of module production scheduling for mixed mode components.

Objective To improve the fitness of customized cheongsam pattern and realize rapid generation of customized pattern, a customized cheongsam pattern generation scheme based on human body size differences was discussed.

Method Firstly, a standard body sample and 27 samples covering various body types were selected from 118 initial screened participants through anthropometric experiments. Then complete the drawing of the standard pattern and evaluate the fitting of the sam-ple clothes,based on the size differences between 27 subjects of various body types and the standard body, a pattern adjustment rule was developed, and the adjusted pattern were evaluated for fitting to verify the feasibility and universality of the adjustment rule. Finally, based on the rules of pattern adjustment, a mathematical model is established. Using Visual Basic programming software, an automatic generation system for cheongsam pattern is established to realize the automatic generation of customized cheongsam pattern.

Results Through human experiments, 27 experimental samples and standard body were selected from 118 initial screened partic-ipants According to the standard body size, draw the basic cheongsam pattern. The sample clothes were made and evaluated for the standard system, and the sample clothes had good try-on effect. According to the characteristics of human body size, 24 anthropometric items are formulated. On the basis of the basic pattern, the pattern adjustment rules are formulated based on the data difference of an-thropometric items between samples, and the pattern adjustment rules are explained from four parts : vertical direction, horizontal direc-tion, shoulder adjustment and armhole adjustment. After 4 steps of adjustment, the adjustment of the experimental sample pattern was completed, and the adjusted 27 patterns were made and evaluated. All the sample effects were consistent with the standard body sample. According to the pattern drawing method and the principle of cubic spline curve, the reference point of the pattern curve is confirmed, and the curve structure line on the pattern is fitted, and the development of the automatic generation program of the custom cheongsam pattern is completed. The human body data of 10 experimental samples were randomly selected and input into the program. The pattern automatically generated by the program was compared with the artificial CAD pattern. The pattern obtained by the two methods showed consistent results in both size data and pattern types.

Conclusion 24 anthropometric items were selected from the three aspects of circumference, length and angle. Based on the size difference of anthropometric items between the experimental sample and the standard sample, the cheongsam pattern adjustment rules were formulated, and the sample clothing experiment was carried out. The results show that the 24 anthropometric items meet the needs of custom cheongsam pattern adjustment, and the pattern adjustment rules based on the data difference of anthropometric items are fea-sible and universal. According to the established pattern adjustment rules, the automatic pattern generation system of customized cheongsam based on Visual Basic can realize the intelligence of individual customized pattern, and the pattern generation effect is con-sistent with CAD drawing. The results show that the automatic pattern generation system developed based on Visual Basic according to the adjustment rules is feasible. This system provides a new approach for large-scale intelligent pattern customization.

Objective Human morphology characterization and quantification play an important role in garment fit, pattern generation and body type classification. The characterization and differential analysis of human morphology under the same number of sizes deserves to be explored in depth. To characterize the morphological differences in body surface shapes under the same size category, this study is focused on the shoulder, chest, and waist horizontal-sections related to the prototype pattern.

Method The three-dimensional point cloud data of 145 young women aged 18-25 years were obtained through [TC]². Samples with the highest proportion of size 160/84 A were selected. K-means clustering was used to quantify the morphological characterization after subdividing the body types that accounted for the largest proportion of the body type, extracting the horizontal circumference cross-section curves of the shoulder, upper bust, bust, under bust, and waist of each classified intermediate body. Due to minor movements or variations in standing posture during 3-D scanning, coordinate system discrepancies may be appeared between the characteristic cross-sections and the system coordinate system. To address this problem, the smallest external rectangle method was applied to align the x and y axes of the characteristic cross-sections in the system coordinate system. Then, each horizontal cross-section was aligned with the mass center as the origin. Subsequently, the cross-section polar diameters based on each body shape morphology were used to plot the centroid-curve for morphological quantification and analysis.

Results The body type of 160/84 A was divided into round-thick body, wide-flat body and medium body, accounting for 7.69%, 53.85% and 38.64%, respectively. The average chest circumference and waist circumference of three types of 160/84A sub-body types were (83.70±0.56) cm and (66.84±5.57) cm, respectively. The shoulder width of the three sub-body types was found to follow the order of wide-flat body > medium body > round-thick body, with a maximum range of 3.82 cm at the shoulder point. The round-thick body has the thickest upper bust circumference, bust circumference, and under bust circumference, followed by the medium body, while the wide-flat body has the thinnest bust circumference, with maximum ranges at the front center of 3.22 cm, 3.62 cm, and 2.97 cm, respectively. The shoulder position of the wide-flat body was 10° away from the anterior-middle direction than that of the round-thick body and medium body, and the chest position of the wide-flat body and medium body was 10°-20° away from the lateral suture direction than that of the round-thick body.

Conclusion The results showed that although the data of height and chest circumference of the same national standard model were similar, there were morphological differences. For the wide-flat body type, the most notable differences occur at the shoulder point and where the cross-section intersects with the lateral suture. In contrast, the round-thick body type shows significant differences at the intersections of the cross-section with the anterior and posterior midpoints. Then, each cross-section was analyzed, revealing that shoulder morphology shows the greatest variation at the shoulder peak. Additionally, the upper bust circumference, bust circumference, and under bust circumference display the most significant differences at the anterior midpoints. Girth morphology differences are most pronounced at the lateral midpoints for each body type.

Objective Aiming at the existing problems of multi-needle electrospinning and needleless electrospinning, petal shaped electrospinning nozzle with multiple tips is proposed and used as the emitting electrode. In the electrospinning process, the structure of the emitting electrode has a great influence on the intensity and distribution of the electric field, and has been an important research object. Therefore, it is necessary to design a new electrospinning emitting electrode and optimize the specific parameters of the new emitting electrode.

Method The nozzle was designed as a semi-closed structure. The upper part was divided into a cylindrical straight pipe multi-channel structure, using the method of equal cross-sectional area of each channel, so as to divide the flow evenly while slowing down the flow speed. The lower part was divided into petal shaped flow channel expansion structure. The curve of petal shaped flow channel was designed by Bezier curve, and the end of the petal was the tip to stimulate multiple jets under low energy consumption. COMSOL finite element analysis software was used to simulate the three-dimensional electric field and find the improved methods of increasing the field intensity and reducing end effect. Finally, experiments were carried out validate of the model.

Results The distribution and change of electrospinning electric field of the new type of electrospinning nozzle were simulated. With the increase of the number of petals, the average electric field intensity of the petal tip decreases from 4.446×10⁶ V/m to 3.336×10⁶ V/m due to the fact that the coulomb repulsion interaction between petals became more obvious, suggesting that the number of petals should not be too many. By comparing the electric field intensity and CV value at the tip of different petal lengths, the field was most uniform when there were four pairs of petals. When the length of the outer petal was fixed, the electric field intensity CV value of the petal tip all showed a trend of decreasing first to a certain value and then increasing with the length of the inner petal changing from short to long. Compared with the parameter models with the best electric field CV value in each group, under the condition that the droplet was fully spread and formed normally, the electric field CV value was the best when the inner petal length was 20 mm and the outer petal length was 21 mm, and the value was 6.74%. The capillary effect was used to widen the petals and the distance between each petal was 4 mm, in order to drain the liquid supply and prevent the solution from leaking in the gap between the petals. After the petal dislocation arrangement, the average electric field intensity became 5.441×10⁶ V/m, and the electric field intensity CV value reached 5.58%, indicating that increasing the average distance between petal tips can effectively improve the uniformity of the electric field intensity. Finally, the metal 3D printing nozzle was used for experimental verification, and the fiber film was obtained. Surface morphology and fiber diameter distribution were examined by Hitachi Flex SEM1000 cold field scanning electron microscope, and the average diameter of the fibers was 258.69 nm with CV value being 15.54%.

Conclusion Petal shaped electrospinning nozzle with multiple tips is proposed in this paper. The optimal structural parameters are 4 pairs of petals, 21 mm length of inner petals, and 20 mm length of outer petals, together with the dislocation arrangement of inner and outer petals. The finite element analysis shows that the new nozzle can effectively combine the advantages of needle and needle-free electrospinning, produce high field intensity and uniform distribution of electrostatic field and can effectively avoid solution volatilization and environmental pollution. The experimental results show that each tip of the petal-like multi-tip electrospinning nozzle can produce a stable and continuous jet, and the total spinning area is large, and the generated fibers are fine and uniform.

Objective Nanofibres have been widely used in many scientific fields due to their excellent characteristics such as large specific surface area and high porosity. Currenly, the electrospinning efficiency of the traditional electrospinning equipment is low, failing to meet the requirement for practical applications. Researchers worked to improve the electrospinning efficiency by increasing the number of nozzles, but there is an "edge effect" problem in multi-nozzle electrospinning. The "edge effect" is generally manifested in the uneven distribution of electric field strength at the nozzle, which leads to electrospinning instability. This study aims to solve the "edge effect" problem through electric field intensity simulation analysis and to design a corresponding multi-nozzle device.

Method Three nozzles were used as the basis for simulation. By changing longitudinal spacing and transverse spacing of nozzles, COMSOL Multiphysics software was employed to analyze the change of the electric field intensity. Following the three-nozzle space electric field intensity simulation analysis, five-nozzle and nine-nozzle simulation analysis of electric field intensity distribution were carried out, the results of which were used for designing multi-nozzle devices.

Results In the three nozzles space electric field intensity simulation, the electric field intensity values of the three nozzles appeared to be the same when increasing transverse spacing, where the transverse spacing was kept to 9.45 cm. However, excessive transverse spacing was found not conducive to the structural design of the multi-nozzle device. The effect of increasing the voltage of the middle nozzle on the electric field intensity was much smaller than the effect of changing the transverse spacing on the electric field intensity. Among them, when the transverse spacing was 5.0 cm, the electric field intensity value was only 2 170 kV/m, which is not conducive to spinning experiments, and the additional high-voltage power required for smaller transverse spacing would cause resource waste in the simulation experiment of changing the transverse and longitudinal spacing. In order to make the three nozzles have the same electric field intensity, the longitudinal spacing of the nozzles was decreased with increased transverse spacing, at 5 cm/0.5 cm (transverse/longitudinal spacing), when the same electric field intensity was 4 394 kV/m. Designing a multi-nozzle structure based on 5 cm/0.5 cm (transverse/longitudinal spacing) not only effectively alleviated the "edge effect" problem, but also facilitated the structural design of multi-nozzle. With 5 cm/0.5 cm (transverse/longitudinal spacing) as the basic parameter setting, under the same conditions, the electric field intensity distribution of the nine nozzles was more uniform than that of the five nozzles. A multi-nozzle device was designed based on simulation results. In the electrospinning verification of the multi-nozzle electrospinning device, the nine nozzles device not only stabilized the electrospinning process, but also improved the electrospinning efficiency by 422.3% compared to the single nozzle device within the same electrospinning time.

Conclusion By changing the relative position of multi-nozzle in space, it can effectively solve the "edge effect" problem in multi-nozzle scenario, make the electric field intensity distribution at the nozzles more uniform, and increase the electrospinning efficiency, and also ensure the stability of the electrospinning process. The method is mainly to adjust the transverse and longitudinal spacing of the nozzles to reduce the influence of the nozzle voltages on each other, so as to make the jet smoother in the deposition process. These results show that changing the relative position of the nozzle space can effectively solve some problems in the multi-nozzle electrospinning process, and also provide some help for the improvement of the multi-nozzle spinning device in the future.

Objective In the textile industry, fabric color is a critical factor affecting the final product's appearance and quality. With the dynamic shifts in fashion trends and increasing diversity in consumer demands, the production pace in the textile sector has accelerated, necessitating more diverse and rapidly updated color options. Consequently, developing a convenient and efficient textile color measurement system is vital to meet the industry's evolving demands. This system is designed for scenarios such as offline trading where traditional measurement system may not be feasible, thereby facilitating accurate color assessment and transactional decisions in the textile domain.

Method In this research, a portable fabric image color measurement system compatible with multiple devices was developed, which comprises a foldable, enclosed image acquisition device and an algorithm for color measurement. The design of image acquisition device incorporated a detachable and collapsible structure, enhancing the system's portability. To ensure accurate color measurement, the study integrated polynomial regression and K-Means clustering algorithms to devise a categorical approach to color measurement. This method involved applying different polynomial regression models based on the specific color categories of the fabrics, thereby facilitating precise color measurement.

Results The process began with capturing images of Datacolor SpyderCheckr24 color swatches using a smartphone. Subsequently, these images underwent processing through a classification correction algorithm developed in this study. The analysis of color differences after correction indicated that the performance of this system closely matched that of the Digieye color measurement system, suggesting that smartphone-captured images, when processed through this system, can approximate actual colors. Furthermore, the system was applied to a set of 25 solid-color woven fabrics. The color measurements obtained from these samples were then compared with the results from the Digieye system. The comparisons revealed a significant degree of consistency, as measured by the ΔE₁₉₇₆ metric and ΔE₀₀ metric, demonstrating the system's efficacy in fabric color measurement,, demonstrating the system’s efficacy in fabric color measurement. To explore the generalization capabilities of the system across various devices, same-color measurement exercises were conducted using smartphones from different brands, including multi-color fabric samples and the aforementioned solid-color woven fabrics. The color differences between the measurements taken from these different devices and those obtained from the Datacolor650 were analyzed. The results of this analysis consistently showed the adaptability of the system in processing images from different smartphone brands, and its ability to provide accurate and reliable color measurements, were irrespective of the device used.

Conclusion The system was applied for color measurement of woven fabric images, including those captured by smartphones from various brands, encompassing both solid and multi-colored fabrics. The results demonstrated that the color measurements from this system align closely with the Digieye system. For model training in this study, Datacolor Spyde Checkr24 color swatches were used. Compared to the dedicated calibrated color cards of the Digieye system, the number of training samples in this study was limited, impacting the measurement accuracy. Future research will focus on expanding the training sample pool and enhancing the color measurement methodology to increase accuracy and extend the practical application of the system in color-related fields.

Objective The production efficiency of a hot-air bonding could be low and not efficient in energy consumption because of uneven temperature and flow field inside the oven. In order to improve the performance of the oven and reduce energy consumption, this research aims to analyze the flow field and temperature field inside the hot-air bonding oven and optimize its structure to enhance the uniformity of the temperature and flow field inside the oven.

Method The internal flow field of the oven was simulated and optimized using the finite element analysis method. A three-dimensional model of the oven fluid domain was established using SolidWorks, and the boundary conditions for simulation calculation were set according to the working conditions of the oven. The flow resistance value of the fiber network was obtained through experimental measurement, and a porous medium model with the same flow resistance was set to replace the actual model of the fiber network, and the Fluent software was used to simulate and calculate the fluid domain model inside the oven. The correctness of the simulation modeling and calculation was verified through experiments.

Results The simulation results of the original oven model showed that the internal flow field had a large flow rate in ducts 1 and 3, and a small flow rate in ducts 2 and 4. There were severe vortices in ducts 1 and 3, causing irregular airflow and significant overall flow field non-uniformity. The lowest temperature on the surface of the fiber network was 130 ℃, with the overall uniformity of 86.43%, and a total standard deviation of 6.97. The data indicates that the temperature distribution on the surface of the fiber network was relatively scattered, and the temperature uniformity was poor. It was found from the optimized oven simulation results that the flow rates in each duct were basically the same. After installing a deflector in the upper duct, the deflector guided and directed the airflow, resulting in a stable airflow in the upper duct and the disappearance of vortices. This significantly improved the uniformity of the internal flow field in the oven. The lowest temperature on the surface of the fiber network was 150 ℃, The minimum temperature was increased by 20 ℃. The worst temperature uniformity at characteristic points was 90.1%, the temperature difference in different areas decreases, the overall uniformity was 93.6%, and the overall temperature standard deviation was decreased from 6.97 to 3.72, and the overall uniformity coefficient increased from 86.43% to 93.06%, indicating significant improvement in temperature field uniformity.

Conclusion After the optimization of the inlet channel structure and the upper duct, the uniformity of the flow field and flow rate inside the oven has been improved, and the generation of vortices in the upper duct has been reduced, resulting in a more uniform airflow. The standard deviation of the temperature on the fiber surface is decreased, the uniformity coefficient is increased, and the uniformity of the temperature field and flow field has been significantly improved. It is recommended to set the temperature at the oven inlet to around 165 ℃, at which the temperature on the surface of the fiber network inside the oven can meet the requirements for the temperature of the dual-component hot-melt fibers. This not only helps to improve the performance of the oven but also achieves the goal of energy saving and consumption reduction.

Significance The application of bone tissue engineering (BTE) techniques to repair bone injuries and defects arising due to trauma, infection, tumors, or pathological fractures remains a major challenge. Silk fibroin (SF) is a natural biomaterial with excellent biocompatibility and controllable biodegradability, and can be a mineralization template to induce the growth of hydroxyapatite (HAp). Recently, SF has received more attention for the application in bone regeneration. Although the development of SF-based bone repair materials has achieved surprising results, many SF-based bone scaffolds with excellent functionality are still in the laboratory stage. Therefore, in the present article, the latest research progress of SF-based materials in bone repair was reviewed, in particular, the strategies and methods to improve the mechanical properties and osteogenic performance were highlighted, in order to promote the innovative development of SF-based bone regeneration scaffolds.

Progress SF is usually prepared into films and hydrogels due to the good film forming and sol-gel transformation properties, and it can also be constructed into porous scaffolds by biomimetic design. Generally, SF films are prepared by casting or electrospinning, then the post-treatments make films insoluble. The softness and flexibility of SF films induced by physical treatment using alcohol reagents are poor, but can be significantly improved by chemical crosslinking or increasing the molecular weight of SF. In addition, combination with sericin can not only improve the softness of the films, but also promote the deposition of HAp. SF hydrogels are typically formed by self-assembly using physical methods like concentration, shearing, ultrasound and electric fields, and also can be prepared by chemical crosslinking. The SF hydrogel yielded by the horseradish peroxidase (HRP)/H₂O₂ reaction system shows impressive viscoelasticity and biocompatibility. Nevertheless, the stability of SF hydrogel is poor in vivo, its mechanical properties and stability can be further improved through double-crosslinking. Freeze-drying, salting-out and 3D printing are commonly used to prepare SF porous scaffolds. Regarding the freeze-drying method, the pore characteristics and mechanical properties of the SF scaffolds can be adjusted through freezing temperature and solution concentration. It is also possible to design a temperature gradient to induce the directivity of the pores. However, it cannot accurately pre-design the internal structure. Salting-outing method can stably control the pore structure, but it is easy to produce more salt residues if the pores connect incompletely. 3D printing allows for pre-designing the internal structure of the scaffolds, but the technology still faces great challenges due to the fluidity of the SF ink. Throughout decades of researches, the mechanical properties of SF materials have been far from satisfactory for the application in BTE. Inspired by the composition and structure of natural bone, inorganic materials such as HAp have usually been considered to modify SF to improve the mechanical properties of the SF scaffolds. Moreover, growth factors and cells are usually incorporated into the SF/HAp composite scaffolds to further enhance osteogenic capacity.

Conclusion and Prospect SF is a natural biomaterial with remarkable biomedical properties. No matter which form of SF material is used for bone defect repair, it shows promising application prospects. However, current researches indicate that the mechanical properties of pure SF-based materials are insufficient, and still have a significant gap compared to natural bone. These deficiencies and osteogenic potential of SF scaffolds can be significantly improved by changing preparation strategies or incorporating inorganic reinforcement materials such as HAp. Furthermore, adding growth factors or cells to SF/HAp composite materials can achieve the repair of critical-size bone defects. In the future research of SF-based bone repair scaffolds, studies focusing on mechanical conduction, neovascularization and matched material degradation need to be considered. Maintaining the activity of growth factors or cells during bone repair is also an urgent problem. These are pivotal for the precise design of SF scaffolds or composite scaffolds that align with guiding bone regeneration and functional recovery. With the development of regenerative medicine and tissue engineering, SF materials are promising candidates to create osteogenic niches with multiple cues and develop different medical devices used in clinical bone regeneration.

Significance Polyphenylene sulfide (PPS) fiber serves as the main material for filter bags, a crucial core component of baghouse dust collectors. It is widely applied in the dust removal of high-temperature industrial flue gas, such as coal-fired boiler plants, municipal waste incineration plants, and power plants. With the increasingly stringent atmospheric emission standards in recent years, the mandatory implementation of ultra-clean flue gas emissions for certain industrial enterprises, as well as the application requirements for high performance, long service life, differentiated and multifunctional, there have been higher requirements for PPS fiber. However, to the best of our knowledge, no comprehensive overviews focused on the continuous development of PPS fibers for filter bag have been reported. For a more comprehensive understanding of the present development status of PPS fibers, this review provides a systematically investigation for the development history and current production capacity of it both domestically and internationally, the research progress and existing issues in the development of PPS fibers for baghouse dust removal. This paper aims to provide insights and guidance to promote the research, production, and application of differentiated functional PPS fiber for high-temperature dust removal in China.

Progress To meet practical application requirements, PPS fiber is developing towards finer and ultrafine deniers, profile fiber, and with antioxidant, catalytic and more functions. At present, the fineness of PPS ultrafine fibers can reach the micron or even nanometer level, and the fabrication methods mainly include melt-blown spinning, melt electrospinning, and sea-island melt spinning. Among them, melt-blown spinning is the most widely used method for the production of PPS ultrafine fibers due to its advantages of larger production output, shorter process, and lower cost. Although profiled PPS fibers include trilobal, Y-shaped, and split shapes currently, only trilobal PPS fibers are commercially available, with Japan's Toyobo being the sole manufacturer. The antioxidant modification of PPS fibers is aimed at addressing the problems of fiber fracture, mechanical strength degradation, and service life shortening of PPS filter when it is exposed to the gaseous components at high temperatures, and further enhance its structural stability in a harsh environment. Currently, the main approaches reported to improve the thermal and oxidation resistance of PPS fibers include surface film-forming method and direct addition method. The surface film-forming method refers to the surface treatment solution prepared by antioxidant, nanoparticle or high-performance resin dipping or spraying it on the surface of PPS fibers or nonwoven material to formulating an antioxidant protective layer. The direct method refers to melt spinning after blending the antioxidant, nanoparticle or high-performance resin with PPS resin directly. PPS-based filter bags with catalytic function are fabricated by loading catalysts such as manganese oxide (MnO₂, Mn₂O₃) and cerium oxide (CeO₂) to decorated PPS fibers or its needle-punching fibrous felts by using in-situ deposition, impregnation calcination and directed coating. It is aimed to achieve a novel integrated filtration material with compact structure and low cost that can provide both harmful gas purification and fine dust removal functions.

Conclusion and Prospect Study on key preparation technologies for differentiated and functional PPS fibers in China commenced relatively late. There are still some problems such as inadequate follow-up in fundamental research, imperfect and immature production processes, and poor product quality stability. Breakthrough in the key research areas and industrial production of differentiated functional PPS fibers such as fine/ultrafine deniers, profile, antioxidant, catalysis, is not only an urgent need for market applications, but also the requirements for the high-quality development of high-performance fiber during the "14th Five-Year Plan" period. Hence, to achieve independent production of differentiated functional PPS fibers, it is imperative for enterprises, universities, and research institutes to collaborate on fundamental raw materials, key equipment, production processes, and other aspects in a joint effort to overcome these challenges.