Tuesday, September 10, 2019

PICKING MOTION ( A PRIMARY LOOM MOTION)

PICKING MOTION ( PRIMARY LOOM MOTION) :

Picking motion is a primary motion that comes after shedding motion. When the shed gets almost opened, the pick ( weft yarn is inserted into the shed from one selvedge to another selvedge. Fabric weaving is not possible without picking motion. There, many kinds of picking motions are used to weave a fabric. 



1 - The pick is inserted through the shed by hands in frame weaving. 

2 - The pick is inserted into the shed by hitting the shuttle carrying weft bobbin in handloom weaving. 

3 - In the power loom weaving, the pick is inserted into the shed mechanical hitting of shuttle carrying weft yarn. The power loom is operated by electricity. 

4 - In shuttle less picking, the picking motion is performed through the non-conventional mechanism. 

Types of picking motion: 

There are the following kinds of picking motions used to weave a fabric:

Negative picking: 

The picking mechanism has no control over the journey of weft yarn till the end of picking motion. The power loom and handloom, air jet loom, water jet loom picking are examples of negative picking. In this kind of picking, there is no control over the weft carrier or weft yarn after throwing them. The shuttle can fly out from the shed too. 

Semi-positive picking: 

This kind of picking, the weft carrier travel into the shed through a weft carrier guide. The weft carrier can not fly out from the projectile loom is an example of semi-positive picking. 

Positive picking: 

In this kind of mechanism, the complete journey of the weft carrier is controlled mechanically. Inserting weft carrier and receiving weft carrier start to travel at the same time from both ends of the loom. The inserting of the receiving weft carrier reaches first at the middle of the weft path. This weft carrier waits to reach the inserting weft carrier. As the inserting weft carrier reaches the middle of the shed, the receiving weft carrier starts to return after weft transfer. The inserting weft carrier also gets returned in its initial position. This mechanism has full control over the journey of picking motion. The rapier loom and frame weaving ( hand picking) are examples of positive picking. 

You may also be interested in the following articles:


Let - off motion, secondary loom motion

Take - up motion, a secondary loom motion

Shedding motion, a primary loom motion

Picking motion, a primary loom motion

Beating motion, a primary loom motion

Schematic diagram of loom

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