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Weaving looms can range from quite simple to very complex. Looms have been used to produce cloth for thousands of years, and while technology has improved the loom, the basic strategies and practices remain much the same. Understanding the parts of the loom can help you learn to weave or simply learn a bit more about how weaving works.
There are three major types of shedding mechanism’s namely tappet, dobby, and jacquard. Based on their technical and operational characteristics on should decide which shedding mechanism to be used
Woven fabrics are made by using two or more sets of yarn interlaced at right angles to each other. Much variety of fabrics are produced by weaving.
Selvedges, often spelled as “selvages,” refer to the finished edges of woven fabrics. These edges are an integral part of the fabric structure and serve several important purposes in the weaving process and the final textile product.
The weft stop motion controls the correct insertion of the weft into the shed. Warp and weft stop motions will stop the loom most immediately when a warp end or a pick breaks off. It avoids the faults disturbing the fabric surface. It helps not degrading the fabric quality. The feeders are supplied together with various outfits and adjustment possibilities, which vary according to the yarn type and count and to the insertion system used.
Weft feeders are feeding devices, which are also called weft storage feeders or weft accumulators, play an important role in the weaving machines where the weft is unwound overhead from the cone and is subjected to abrupt accelerations due to the drawing-off tension exerted by the insertion element. The balloon which is formed at each insertion can cause coil sliding and snarls, owing to the difficulty of braking adequately the yarn and to the high unwinding speed of the yarn from the cone.
Special equipments to improve efficiency and accuracy of weaving machines, reducing manual work are required. With a view to increase the efficiency and the flexibility of the weaving machines, the manufacturers have made considerable efforts to find solutions capable of simplifying and speeding up the operations and the machine settings at style changing and to permit coping better with particular production requirements.
The latest weaving machines are equipped with microprocessor or PLC units which ensure continuously the control, the drive and the monitoring of the various machine members and of the various functions. One of the ways to increase production is to design and manufacture particular weaving machines which can offer very high weft insertion rates.
The angle which is formed by the raising threads with the threads remaining in low position is called shed. The shed must be as wide open as to permit the easy passage of the weft insertion element. The shed can be obtained by either moving the heald frames or by directly moving the heald frames through. The machines used to form the shed are cam machines, dobbies, and Jacquard machines.
Warp let-off system has a frequency converter, which is intended for letting off from warp beam or feeding unit. The drive is mounted either on the weaving machine or on a frame positioned behind the weaving machine. The let-off starts with a machine running signal; the speed of the let-off motor is controlled by a proximity switch mounted on the whip roller system and an internal speed memory. An alarm signal switches the weaving machine off in case of over tightened warp or any other error.