Saturday, December 24, 2016

Loop Transferring Process in Weft Knitting

What is loop transfer in knitting?
A loop that is displaced after being formed so that it combines with an adjacent loop, or so that it appears in a different wale, is said to have been transferred.

Transferring a full or part of a needle loop or sinker loop on to an adjacent needle, either in the same bed or in an opposing bed is called stitch or loop transfer. The stitch which is formed by this loop transfer is called loop transfer stitches.

Objects of loop transfer:

The object of loop transfer is to achieve shaping, produce a design, or change the stitch structure. Transferring is used to generate holes in the fabric to form lace-like effects. Transferring can be used, to produce structural effects by inclining wales of both plain and rib fabrics. This is also used to produce cables by exchanging two or more groups of wales with one another. In addition, loop transfer is used in ladies stockings, when producing the double-thickness, plain fabric, in-turned welt. It also used in running-on and doubling rib loop fabric on to the needles of a straight bar frame to form the rib border of a garment part. Loop transfer is used when running the loops of two separate fabrics onto the points of a linking machine for linking these fabrics together.

Loop Transferring Process:
There are two types of loop transferring process. One is manual loop transferring process which is transferred by hand. And another is automatic loop transfer process.

Loop transfer by hand-controlled points is a tedious and skilled operation, but automatic loop transfer requires a specific arrangement of specially shaped needles or transfer points. The following description relates firstly to manual transfer, then to automatic transfer on the sweater knitting machine.

Manual loop transfer or Transfer by hand:
The transfer by hand is executed by means of a narrowing handle or transfer needle of which the size of the point varies according to the machine gauge. To transfer a stitch of one needle to a neighboring needle by means of the narrowing handle.

Automatic loop transfer:
The process of automatic loop transfers on V-bed knitting machines and the working mechanism taking part in loop transfers are shown in the following figures. For loop transfer an auxiliary element must be brought in action and it is the transfer unit. The latch needle has a recess, 'a' which accommodates the transfer unit for loop transfer. The process of loop transfer is fulfilled in the following steps:

Automatic loop transfer
Fig: Automatic loop transfer
  • Needle Selection for loop transfer (a);
  • Rising the needle to such a position that the loop remains on the open latch (a);
  • The transfer unit 1 lowers onto the needle recess (b);
  • The needle rise, coupled with the transfer unit, and the transfer unit takes over the loop (c);
  • The rising transfer unit releases the needle which lowers into the needle bed (d & e);
  • Now, the transfer unit is shifted by one needle spacing to the needle which is to take over the loop carried by the transfer unit (e);
  • New needle takes the transferred loop over (e & f).