Abstract:

Objective At present, the warp knitted shoe fabrics on the market are mainly single- and double-jacquard shoe fabrics. However, due to the limitation of the number and configuration of the jacquard guide bars, it is difficult for single- and double-jacquard shoe fabrics to form the mesh structure both on the front layer and the back layer, and the color effect is singular. Therefore, by analyzing the process difficulties of knitting the target shoe fabrics with double-jacquard guide bar configuration, a three-jacquard bar arrangement scheme was proposed. The three-jacquard knitting process was further studied, and the three-jacquard shoe fabrics with both three-dimensional (3-D) mesh structure and three-jacquard color effect were created, which enriches the product variety of warp knitted shoe fabrics, and a design method reference for the development of other three-jacquard shoe fabric was provided.

Method By analyzing the jacquard guide bars configuration schemes of RDPJ6/2 and RDPJ7/2 warp knitted jacquard machines, the knitting function of every jacquard guide bar and general guide bar was studied, the technical difficulty of knitting the 3-D mesh structure and three-jacquard color effect was explored, and the configuration scheme of three-jacquard guide bars was proposed. Based on the RDJ6/3 guide bar configuration scheme, the jacquard process principle of three-dimensional mesh structure was studied, including the design of jacquard structure and jacquard offset information. At the same time, the process principle of using polyester, cationic modified polyester and polyamide to form three-jacquard color effect was studied, and the raw material piercing scheme and specific jacquard effect were analyzed in combination with the guide bar configuration of RDJ6/3. By using WKCAD design software and RDJ6/3 warp knitting machine, the three-jacquard spacer shoe fabrics with 3-D mesh structure and three-jacquard color effect were knitted on the machine according to the jacquard structure design, raw material threading design and lapping process design of shoe fabrics.

Results The configuration of three-jacquard guide bars are able to obtain three-layer shoe fabrics with double layers jacquard effect with the new configuration scheme RDJ6/3(Fig. 1). Among them, a back layer with mesh structure could be formed by GB1 and JB2, the spacer layer could be formed by GB3, and the three-jacquard color effect could be formed by JB4 and JB5 with different yarns, with a front layer with mesh structure could be formed by JB5. On the RDJ6/3 warp knitting machine mentioned above, the first jacquard guide bar (JB2) was designed to form a back layer mesh in the front needle, the third jacquard guide bar (JB5) was designed to form a front layer mesh with the same position and size as the first jacquard. The spacer guide bar GB3 was located in the middle of the first and third jacquard guide bar, connecting the non-mesh area of the both layers to form a 3-D mesh structure. The jacquard principle of three-jacquard color effect was to use the difference of dyeing properties of polyester, cationic modified polyester and polyamide into different half-size jacquard guide bars, and then form color patterns through the change of jacquard stitch.

Conclusion Combined with WKCAD software, the drawing of jacquard pattern and the design of jacquard structure were achieved, and 111.11 dtex(36 f)polyester, 111.11 dtex(48 f)cationic modified polyester, 33.3 dtex polyester monofilament and 77.78 dtex(48 f)polyamide were selected as yarns. The knitting of shoe fabrics with three-dimensional mesh structure with double-sided mesh and white, blue and black three-jacquard color effect was realized on RDJ6/3 warp knitting machine, which truly integrated structural functionality and color decoration with new warp knitted shoe fabrics. The breakthrough of the key technology of three-jacquard was achieved, the product style library of warp knitted three-jacquard shoe fabric was expanded, and theoretical and practical reference for the further development of three-jacquard shoe fabric was provided.

Key words: knitting technology, warp knitted spacer shoe fabric, double needle bar warp knitting machine, three-jacquard color, three-dimensional mesh structure