Objective In order to bypass the limitation of the number of heald frames on the preparation of three-dimensional woven fabric and improve the design-ability of three-dimensional woven fabrics and weaving process, a weaving method of three-dimensional spaced jacquard fabric with variable spacer core structures is proposed. Method An electronic jacquard loom was modified for weaving spacer fabrics. The ground warp is controlled by two groups of heald frames with different heald eye positions to form double sheds and the longitudinal warp was controlled by jacquard together with the use of weaving CAD. With the aid of the support rod, the longitudinal warp was interwoven with the weft to form the ground fabrics. When the movement direction of the support rod was changed, the longitudinal warp would cross between the two ground fabrics and connect the ground fabrics into one three-dimensional structure, so as to complete the weaving of three-dimensional spacer Jacquard fabric. Results A three-dimensional spacer fabric is composed of three groups of yarns, where the ground weave warp yarn constitutes the fabric length direction, the surface weft yarn forms the width direction of the fabric, and the longitudinal warp yarn constitutes the fabric thickness direction. The weaving structure suggested that the longitudinal warp yarns are divided into two groups, and the yarns are interlaced with the upper and lower weft yarns in turn to form a three-dimensional spacer fabric with solid core. The longitudinal warp yarn is controlled by jacquard. According to the jacquard CAD design, with the assistance of the support bar, the weft yarn can be interweaved in different ways, forming a three-dimensional spacer fabric with variable hollow core structure. The longitudinal warp can be evenly divided into two groups with the help of the supporting shaft, and the yarn can be interwoven with the upper and lower weft separately. The longitudinal warp can also move vertically with the supporting stem between the ground tissues. When the supporting rod changes the direction of movement, the longitudinal warp will also move with it, completing the exchange of longitudinal positions, connecting the upper and lower layers of ground tissues into a whole. The surface texture of the test fabric is plain weave structure, the side section is hollow core structure and solid core structure are interlaced (Fig.5(c)), and the hollow part is square structure(Fig.5(b)). Through the tensile test of solid/hollow three-dimensional spacer fabric, as shown in Tab.2, the breaking strength of hollow fabric is reduced by about 20%, and the breaking elongation is increased by about 8% compared to the solid fabric, because there are fewer longitudinal warp junction points in the hollow fabric. Moreover the hollow structure makes the fabric bear uneven force when being stretched, resulting in a decrease in strength. The hollow structure also enhances the deformability of the spacer fabric. Conclusion This paper proposed a production process of three-dimensional spaced jacquard fabric with variable hollow core structure. In actual production, the spacing distance of three-dimensional fabric can be adjusted by the warp let off of longitudinal warp and the movement height of the supporting rod. Using this weaving method, healds of different heights can be adopted to design the weaving process of three-shed or multi-shed, so as to complete the weaving of multi-layer spacer hollow core fabric. Compared with the strength of solid core spacer fabric, the strength of hollow core spacer fabric in both warp and weft directions decreased, and the strain increased slightly. This process can produce three-dimensional fabric with variable hollow core structure under the premise of less strength damage, and increase the designability and application field of three-dimensional spacer fabrics. © 2023 China Textile Engineering Society. All rights reserved.
