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  1. Major Loom Systems
  2. Standard Properties of Woven fabrics

Major Loom Systems

Tappet Shedding System

The tapping shedding system is a motion of tappets and cams that cause shafts to be raised to form the shed. The mechanical arrangement of this system occupies so much of space that it can accomodate maximum of eight shafts and that is why its eight shafts represent maximum size of its weave repeat. This limits to the weaving of plain weaves, simple twills and simple sateen and satin weaves. Incase, the repeat of the desired design require more than eight shafts, then a dobby loom has to be used. Fig. shows tappet shedding with roller reversing.

Dobby Shedding System

A mechanism for controlling the heald shafts of a loom. It is required when the number of heald shafts or the number of picks in repeat of pattern or both are beyond the capacity of tappet shedding This is a shedding system capable of having upto 32 shafts. Being able to accomodate up to 32 shafts, a much greater weave repeat and complicated design is possible.

Jacquard Shedding System

This shedding system has no shafts. A harness consisting of as many cords as there are ends in the warp sheet connects each end individually to the Jacquard machine situated high above the loom. Therefore, each warp can weave independently of all the others. Since each warp yarn can be controlled individually, the greatest weave repeat is possible . This enables most intricate designs to be woven.

Standard Properties of Woven fabrics

Weight Range

Very heavy > 13 oz/yd2
Heavy > 6 - 13 oz/yd2
Medium > 4 - 6 oz/yd2
Light > 2 - 4 oz/yd2
Very light < 2 oz/yd2

Width range

Broadloom 108”
Medium or average 45, 54, 60, 72”
Narrow 27 - 36”
Very narrow < 12”