Working principle of large circular knitting machine

The yarn forms a loop during the process of forming a circle, which becomes a knitted fabric through longitudinal threading and transverse connection. So forming circles is the basic process of knitting. The process of forming a coil can be decomposed into the following stages in order: rewinding - moving the newly formed coil (called the old coil) from the needle hook to the needle rod; Pad yarn - feeding the yarn onto the knitting needle; Bending yarn - bending the yarn into a coil shape; Carrying yarn - move the newly padded yarn or newly bent coil into the needle hook; Closed - closing the needle opening of the knitting needle; Collar - trap the old thread onto the closed needle hook

Loop connection - the new yarn or coil meets the old coil inside and outside the needle hook; Detachment - Remove the old coil from the needle hook and place it on the new coil; Circling - forming a closed and predetermined size new coil of yarn; Pulling - Pull the new coil away from the coiled area. This new coil will become the old coil in the next winding cycle. The process of forming circles can be divided into two types: needle weaving and knitting. In the process of knitting, the various stages of knitting are carried out in the order mentioned above. In the process of weaving into loops, the bending of yarn begins with the shedding of loops and occurs simultaneously with the looping stage. On some knitting machines, each needle completes the process of forming circles in sequence; There are also some knitting machines that perform the process of forming loops with only one needle in a row simultaneously

Knitting production can not only weave various types of raw fabrics, cut and sew them into various knitted fabrics, but also directly weave and shape products on machines to produce fully formed or partially formed products. The use of forming technology can save raw materials, simplify or eliminate cutting and sewing processes, and improve the wearability of products. Knitting production has developed rapidly due to its short process, strong adaptability of raw materials, fast variety modification, wide product range, low noise, and low energy consumption. Since the 1970s, the productivity of knitting machines has greatly improved. For example, circular weft knitting machines (tongue knitting machines) can weave about 3000 horizontal loops per minute, while most warp knitting machines have a weaving width of 427 centimeters and can weave up to 2000 horizontal loops per minute. The maximum speed of a single needle cylinder sock machine can reach 1000 revolutions per minute

The use of electronic technology to control the operation of knitting machines has further improved machine efficiency. Installing various active yarn feeding devices on the machine can improve product quality. Attaching some mechanisms to the machine can weave knitted fabrics with various organizational structures and different purposes: for example, using a needle selection mechanism to make the needles work according to a pre arranged program to weave jacquard knitted fabrics; Using a combing mechanism to feed loose fibers into knitting needles to weave long plush knitted fabrics; Using warp and weft lining devices to weave warp and weft lining knitted fabrics. There are a wide variety of knitting machines, with over 350 types. With the development of new varieties of chemical fibers and post-processing techniques, the properties of knitted fabrics such as scratch resistance, no ironing, and wear resistance have been improved. The application of finishing techniques such as carding, grinding, shearing, embossing, and pleating has expanded the variety of knitted fabrics