Picking motion (A primary loom motion):-
Picking motion (A primary loom motion):-
Picking motion is a primary motion that comes after shedding. 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 is many kinds of picking motions are used to weave a fabrics.
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 bobbins in handloom (fly shuttle ).
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 shuttleless Picking, the Picking motion is performed the non-conventional mechanism.
Types of picking motion:-
There are the following in kinds of picking motions are used to weave a fabric,
1) Negative picking.
2) Semi-positive picking.
3) Positive picking.
4) Under-pick picking motion.
5) Over-pick picking picking motion.
(1) Negative picking motion:-
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 example of negative picking. In this kind of Picking, there is no control over the weft carriers or shuttle ( having weft in it) after throwing them. The shuttle can fly out from the shed too.
(2) Semi-positive picking motion:-
In this kind of picking, the weft carrier travels into the shed through a weft carrier guide. The weft carrier can fly out from the loom, projectile loom in an example of semi-positive picking.
(3) Positive picking motion:-
In this picking 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 the 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 start 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.
Ref:-https://www.textileadvisor.com
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