Knitting process, according to different process characteristics, knitting production is divided into two categories: weft knitting and warp knitting. In weft knitting production, after the raw material has been wound, the package yarn can be directly put on the machine for production. Each yarn is sequentially placed on each knitting needle of a weft knitting machine in the weft direction to form a weft knitted fabric. In warp knitting production, the raw materials are wound and warped, and the yarns are arranged in parallel and wound into warp beams, which are then produced on the machine. The yarns are unwound from the warp beam, and each yarn is placed on one or at most two knitting needles of a warp knitting machine in the longitudinal direction to form a warp knitted fabric. There is also a method of combining weft knitting and warp knitting on some knitting machines. At this time, two sets of yarns are arranged on the knitting machine, one set is covered by the warp knitting method, and the other set is covered by the weft knitting method. The loops formed by the same yarn are arranged in the weft direction in weft knitted knitted fabrics and in the warp direction in warp knitted knitted fabrics.