Abstract:

Objective In order to explore possibilities of developing whole garment knitted products with computerized flat knitting machines, different design methods and forming processes of whole garment products were explored. Taking the knitted sports knee pads as the research object, the design method of the one-piece local multi-layer structure was established by local structure manipulation, leading to the development of various fully formed products with required functionalities.
Method The knee data was obtained by the three-dimensional scanning system, the two-dimensional paper sample size of the knee pads was determined, and the dimensions of the process parameters were substituted into the two-dimensional paper sample to obtain the knitting process parameters for the one-piece knee pads. Local change stitch for knee pads was experimented and designed, and the one-piece partial multi-layer structure was developed by the double needle bed computerized flat knitting machine and the SDS-ONE APEX3 software system. Different loop structures were designed in the patella part and sides of the knee pads to achieve the required protection.
Results With the cooperation of the special yarn self-propelling mouth of the double needle bed computerized flat knitting machine, density triangle and elastic yarn feeder, a three-layer loop structure was knitted at the knee patella (Fig.6), to knit a section of knitted fabric with certain thickness and good elasticity to replace the conventional protective materials.High elastic rubber band and camel hair (Fig.10) were used to increase the elasticity of the overall and local multi-layer structures of the whole garment motion knee pad. Through orthogonal test, the best knitting scheme was determined, and the knee pads with the highest elastic recovery rate (Tab.2) was obtained.
Using the double needle bed computerized flat knitting machine, a section of plain/ring/plain local multi-layer structure was knitted in the knee pad to replace the silicone protective sheet of the conventional sports knee pad. On both sides of the knee pad, and the lower end of this section of air layer was closed and the upper end was open. A section of air layer structure with two ends connected and the middle separated was knitted to fix the spring strip (Fig.12).
The three-layer patella protective layer knitted by the whole garment method was found 68.2% lighter than the conventional silicone patella protective sheet (Fig.13). In addition, the whole garment method eliminated the necessity for cutting and sewing after knitting, and avoided the loss of raw materials in the cutting process, resulting in benefits in saving labor costs, shortening production process, and reducing the loss of raw materials.
Conclusion This paper explores a local multi-layer knitting method of a double needle bed computerized flat knitting machine. By structural design and technological practice, three layers of three-dimensional spacer tissue are used as the patella protective layer at the front of the knee instead of the conventional sports knee pad. A double-layer air layer structure is knitted at the side to fix the spring strip, changing the conventional fixation method of hot-melt adhesive bonded cloth. Sports knee pads knitted with whole garment technology have greatly improved the comfort, shortened the processing flow in production, reduced the consumption of raw materials, and met the requirements of current green development.The development of one-piece sports knee pads expands the application direction of whole garment technology. The experimented knitting method of one-piece partial multi-layer structure can be applied for more applications, with required functionality and high added value.

Key words: one-piece, double-needle bed computerized flat knitting machine, sports knee pad, multi-layer structure