Abstract:

This project work deals with the behavior of weft yarn in terms of twist during airjet weaving. The twist in the yarn decides its structure and strength, and when it is in the fabric as a weft, its twist has an impact on fabric properties like strength, drape, dye uptake, etc. The trials are conducted for analyzing the effect of single hole and shower-type relay nozzle on the twist of the weft yarn for 13.12 Tex (45S Ne) (CVC-Chief Value Cotton) yarn and the same construction of fabric. The multi-hole relay nozzle results in higher twist loss than the single-hole relay nozzle. The effect is also observed for the weft-way tensile properties at the left and right side of the fabric. On the right side of the fabric, lesser strength has been found than on the left side of the fabric. It is found that the air pressure of the nozzles is directly proportional to the twist in the weft yarn.

The package from the loom shed has been tested for actual twist in the weft. Afterwards, the weft is extracted from the fabric and tested for twist on both the left and right sides of the fabric. Similarly, the left and right sides are used for measuring the tensile properties of the fabric.

Introduction:

Airjet weaving is a type of weaving in which the filling yarn is inserted into the warp shed with compressed air. Upon release of the filling yarn by the stopper, the filling is fed into the reed tunnel via tandem and main nozzles. The tandem and main nozzle combination provides the initial acceleration, where the relay nozzle provides high air velocity across the weave shed. Profiled reed provides guidance for the air and separates the filling yarn from the warp. The insertion medium mass to be accelerated is very small, relative to the shuttle, rapier, or projectile machines, which allows high running speeds.

A typical timing diagram of main and relay nozzles is shown in the following chapter. The timed groups of relay nozzles blow air on the tip of the yarn across the machine width. As a result, the yarn is pulled by the air at the tip (rather than pushed from behind) throughout the insertion, minimizing the possibility of buckling which may cause weaving machine stops. This also assures the lowest possible air consumption.

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The authors are associated with the Centre for textile functions (CTF), NMIMS MPSTME Shirpur campus, Shirpur Dist- Dhule, Maharashtra.