The principle of jacquard of large jacquard. There are […]
The principle of jacquard of large jacquard. There are two differences between the production of large jacquard fabric and small jacquard fabric. One is that the large jacquard does not use a brown frame, but uses a more complex combination of faucet + through wire + eyepiece + brown silk; the second is large Jacquard pattern curtains are generally very long. If there are N wefts in a jacquard position, N pattern patterns must be equipped. There must be a special bracket for hanging the pattern curtain. If the front and back sides are mistaken or the left and right ends are adjusted, the wrong flower shape will be knitted. It is also very troublesome to find the wrong pattern. The bracket of the pattern curtain is usually arranged above the loom with the jacquard faucet. A small jacquard plate usually has a maximum of 24 pits, which are used to control the lifting and weft selection of the brown frame. A large jacquard plate will have thousands of pits, which correspond to the number of pins on the jacquard faucet. The hole is aligned with a needle, and whether the hole is punched to control whether to raise the brown. A hole controls the movement of several warp yarns, which are one or more of each flower on the fabric. The root is the principle that warp yarns with the same trajectory can be hung on a dragon hook through their respective through wires. If the number of roots exceeds the load capacity of the dragon hook, a few more hooks can be shared. In many cases, one hook is shared. The number of hanged wires is the number of flowers in the whole cloth. Their information transmission process is pattern board --- pin --- dragon hook --- through wire --- heald --- warp.
The advanced computer jacquard faucet big jacquard machine can save the trouble of making patterns and arranging a bunch of patterns to run. At the same time, the time from design to driving is greatly shortened, and it is easy to modify. The efficiency has been greatly improved, but the equipment investment is much higher, often ten times or more than that of ordinary machines.
Jacquard fabrics can be made with limited yarn counts and densities like ordinary fabrics, and not all patterns can be lifted. Because it is a large jacquard, warp yarns have many different weaving structures and may have different weaving tightness. , So that the warp yarn tension unevenness phenomenon occurs during the weaving process. If the tension unevenness is slight, it can be produced, the cloth surface has some unevenness, or it is prone to star jumping. If it is severe, weaving is not possible, or the weaving efficiency is very low, there are many defects. This requires that the feasibility of production be fully considered when designing the jacquard process, which mainly depends on the organization of the flower and ground parts, the size of the block surface of the jacquard part, and whether the flowers are evenly distributed on the cloth surface.