Abstract:

Objective Warp knitted jacquard mesh structures for shoe making are mostly created using tricot stitch, satin tricot stitch and chain stitch. The stitches are generally elliptical and lack three-dimensional structural features, and mesh structures are simple in style. Based on the characteristics of the double needle-bed jacquard stitching with "1×8" offset signals, the two-dimensional (2-D) and three-dimensional (3-D) jacquard mesh mechanisms for shoe application were further analyzed, and a 3-D mesh structured shoe fabric was designed and developed on RDPJ6/2 warp-knitting machine, aiming to improve the wearing comfort and fashion appearance of shoe fabrics.

Method The formation principles of double needle-bed jacquard stitches with 8 offset signals were studied. By analyzing the rules guiding the overlap and underlap, the stitches were categorized as single needle-bed jacquard stitch and double needle-bed jacquard stitch, and the 3-D loop structure and jacquard effect were further studied. The design mechanisms for diamond, rectangle and hexagon of 2-D mesh structure were explored based on the analysis of the underlap of single needle-bed jacquard stitch. Through the combination design of the jacquard structures, the design mechanisms for the single-mesh, double-mesh separation and double-mesh connection for 3-D mesh structures were studied. By selecting the raw material and jacquard stitch, a shoe fabric product with 3-D mesh structure was knitted on the RDPJ6/2 warp-knitting machine.

Results The results showed that single needle-bed jacquard stitch could be looped on either the front needle bed or the back needle bed to create four jacquard effects, i.e., the thick effect, thin effect, mesh effect and floating line effect (Fig. 2). The underlap of thick/thin/mesh-birdeye point connection jacquard stitch was in the middle layer and it had double-layer jacquard effect, forming a thick, thin or mesh effect on one layer and a birdeye effect on the other layer (Fig. 3). The underlap of birdeye point-birdeye point connection jacquard stitch was also located in the middle layer, and single or multiple birdeye effects were formed on both layers (Fig. 4). The combination design of warp knitting chain stitch, tricot stitch, miss-lapping stitch and two-needle stitch would form 2-D mesh structures with different shapes such as diamond, rectangle and hexagon (Fig. 5). The 3-D mesh structure was classified into two types of 3-D mesh structure on single layer, 3-D mesh structure with two separate meshes on double layers and 3-D mesh structure with underlap-connective meshes on double layers (Fig. 6, Fig. 8, and Fig. 10). The double-layer mesh structure not only increased the three-dimensional diversity of the mesh structure, but also brought better air circulation for the shoe fabric, supplemented by the product of 3-D mesh structure jacquard shoe fabric for verification (Fig. 11).

Conclusion The double needle-bed jacquard process with 8 offset signals can significantly improve the diversification and 3-D effect of the mesh structures. Innovation in the 3-D mesh structure helps promote the fashion and functionality of warp knitted jacquard shoe fabrics. The three-dimensional mesh structure could have intelligent application prospects by virtue of its good air permeability and three-dimensional structure. In the future, testing experiments on the air permeability and bursting performance of the mesh structure can be carried out to further analyze the intelligent application scenarios of different mesh structures.

Key words: warp knitted shoe fabric, double needle-bed warp-knitting, jacquard technology, double needle-bed jacquard stitch, two-dimensional mesh structure, three-dimensional mesh structure