Wednesday, May 12, 2021

Parallel picking or parallel weft insertion systems

 Parallel weft insertion method:

The weft insertion process comes after shedding motion. When the shed gets almost opened, the weft yarn is inserted into the shed through any type of picking mechanism. 

When two or more picks are inserted simultaneously during one picking cycle in a shed, this kind of weft insertion method is called the parallel weft insertion method.  In simple words, first of all, the shed gets opened. Now two or more picks are inserted at a time in this created shed. 

The productivity of the loom gets increased if we use a parallel weft insertion system. The cost of production also gets decreased.

There are some limitations with parallel picking. 
If weave demands a single pick, the parallel picking is not usable.

The parallel picking is not usable when very coarse weft yarn is used. 

The parallel weft insertion can be achieved in conventional picking as well as in non-conventional picking systems.

Parallel weft insertion with conventional picking system:

There is only one way to apply parallel picking in a conventional picking system. As we know that the picking motion is performed by shuttle in a conventional picking system. Two ends of the weft yarn are wound together on the weft pirn. If we wind two ends together on the bobbin during pirn winding, some difficulties occur during winding. If we combine two ends of the weft yarn together on a parallel winding machine and transfer this parallel yarn on the pirn, the difficulties are resolved. The yarn preparation cost gets increased slightly.

Now, these pirn bobbins are used in the parallel weft insertion method on shuttle loom and parallel weft insertion gets achieved.

Non-conventional parallel weft insertion system:

The parallel weft insertion can be efficiently achieved in rapier looms and air-jet looms. 

In the rapier looms, Two or more yarns of very fine to medium count yarn can be inserted in parallel picking. You can insert two or more picks at a time in the same shed by combining two or more ends of weft yarn or directly without combining.

If we use combined weft yarn, there weft wise fabric defects may occur. Extra doubling cost also occurs.

If we use two or more weft packages without combining, The fabric quality doesn't affect and the cost of production also decreased. There is required a suitable weft detection system to support parallel picking.

If we insert two or more wefts in the air-jet loom, we can use fine count yarn only. Parallel picking is achieved by yarn doubling or without yarn doubling. Probably, parallel picking is performed without doubling in air-jet looms to reduce the cost of production. The quality doesn't affect in any way.

Please click on the below video link to watch the full topic in Hindi:

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