Weaving Technology | Weaving process

In order to interlace warp yarn and weft yarn to produce fabric on any type of weaving machine, three operations are necessary. Shedding separating the warp yarn which run down the fabric, into two layers to from a tunnel known as the shed. Picking passing the weft yarn, this traverses across the fabric, through the shed. Beating up pushing the newly yarn insert length of weft, known as the pick, into the already woven fabric at a point known as the fell.

These three operations are often called the primary motion of weaving. These motions must occur in a given sequence, but their precise timing in a relation to one another is also of extreme importance on a power loom. Two additional operations are essential if weaving is to be continuous Warp control let of this motion delivers warp to the weaving area at the required rate and at a suitable constant tension by unwinding if from a flanged tube known as the weavers beam. Cloth control this motion withdraws fabric from the weaving area at the constant rate that will give the required pick spacing and then winds it onto a roller. After these operations took place a weaving cycle is completed. Weaving cycle is repeated over and over again until the cloth reaches the desired length.

The warp unwound from the weaver’s beam passes round the back rest and comes to the held frames which are responsible for separating the warp sheet for the purpose of shed formation. It then passes through the reed, which holds the threads at uniform spacing and is also responsible for beating-up the last inserted pick. All this yarn unites again in the fabric at the point of cloth fell. The cloth then passes over the front rest, round the take up roller, and is wound onto the cloth roller. A drop wire signals the loom to stop immediately after a warp end breaks off.

Bottom closed shed this kind of shed is produced by giving motion only to yarn that are to from the under the upper line. Under this condition the warp is level on the bottom line. Hence in order to from a top shed, it is necessary to move some threads through a space equal to twice the depth of a shed, once up and one down before a frees selection is made.

Centre closed shed is produced by imparting an upward movement to those yarn which are to form the top line and a downward movement to the threads which are two forms the bottom line. Then after insert a pick, both the lines meet at the centre between the highest and lowest line of a divided warp.

Open shed in this types of shed, the ward threads from two stationary lines, one at the top and another at the bottom. After inserting a pick change are made by carrying yarn from one fixed line to the other. So some yarn are lowered from the top line and some are raise from the bottom line during the change, raising and lowering of the yarn occurred simultaneously.

Semi open shed this is formed under both open and closed principles. Here a stationary bottom line is retained, but yarn from the top line either passes to the bottom at one movement, or are arrested midway and again carried to the top.