Tuesday, September 10, 2019

PICKING MOTION ( A PRIMARY LOOM MOTION)

PICKING MOTION ( PRIMARY LOOM MOTION) :

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



1 - The pick is inserted through 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 non conventional mechanism. 

Types of picking motion: 

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

Negative picking: 

The picking mechanism which has not any kind of control over the journey of weft yarn till the end of picking motion. Power loom and handloom, airjet loom, water jet loom picking are the 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: 

Theis kind of picking, the weft carrier travel into shed through weft carrier guide. The weft carrier can not fly out from the the projectile loom is the example of the 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 same time from both ends of the loom. The inserting 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 in the middle of the shed, the receiving weft carrier start to return after weft transfer. The inserting weft carrier also gets returned in its initial position. This mechanism has full control over journey of picking motion. The rapier loom and frame weaving ( hand picking) are the examples of the positive picking. 

                                   The end






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