Structural design and thermal-moist comfort of weft knitted knee pads

Objective In order to improve the traditional knitted knee pads that are reported with poor heat and moisture performance and lack of clear structural partitioning, this research was set to study the structural design of weft knitted shaped knee pads and methods to improve heat and moisture comfort from the perspectives of pad processing and pattern design. Method Firstly, the morphological characteristics and thermal and humidity characteristics of human legs were analyzed, and 14 different structured samples were prepared from yarn materials aiming to achieve good thermal and humidity properties, and air permeability and liquid water management tests were carried out. The partition structure designs of the knee pads combined with the characteristics of the legs were studied. Finally, the knitted knee pads were tested by thermal imaging, and temperature and humidity related performance were comparatively studied. Results The leg structure was studied according to the grid line division ( Fig. 1) , and the leg was divided into different heat and moisture density areas by combining human body heat with moisture characteristics (Fig. 2) . The prototype knee pad structure was designed according to the leg shape (Fig. 6) , and the functional partitioning design was carried out through the heat and moisture characteristics to establish the functional partitioning structure of the knee pad (Fig. 7). Through the experiments related to thermal and moist comfort, it was concluded that air permeability data graph, the air permeability of the mesh structure and the set circle structure only differ by about 80 mm/s, which was 26. 7% higher than the air permeability of the ribbed structure (Fig. 4) . In addition, in the thermal imaging pictures, after 20 min, sweat was discharged through the coil structure, and then the air took away the moisture to achieve the cooling effect. Because of this, the overall temperature decreased fast, and the difference between the thermal imaging temperatures before and after situations was small. In the overall rating table of the moisture management test, the rib sample and the composite sample scored lower than the mesh sample by 0. 75 and lower than the imitation rib sample by 0. 33 (Tab. 2) . The mesh sample and the loop sample scored close to each other, both of which had better moisture management performance. In the graph of temperature and humidity change, the sample knee pads reached the maximum humidity at 25 min and then dropped rapidly after 5 min, the commercial knee pads reached the maximum humidity at 21 min and then started to decrease only after 10 min (Fig. 12). Conclusion The various fabrics with thermal humidity function prepared by using weft knitting forming principle and single guide moisture principle are better than other samples in terms of thermal humidity performance of mesh and collector loop samples, and are suitable for thermal humidity comfort research of knee pads. By analyzing the morphological characteristics of human legs and thermal and humidity characteristics, the functional partitioning of knee pad structure was designed, and a weft knitted shaped knee pad partition matching the thermal and humidity needs of legs was established on the basis of satisfying the curved surface of legs, and the partitioned designed knee pad has better thermal and humidity comfort than the traditional knitted knee pad. Compared with knitted knee pads with a single structure and vague partitioning, knee pads with heat and moisture partitioning have better heat and moisture comfort, which can increase the comfort of the wearer during sports and improve sports performance. © 2023 China Textile Engineering Society. All rights reserved.