Problems and solutions of textile

How to Control Loop Length in Knitting Machine

How to Control Loop Length in Knitting Machine

Rana Sohel
B.Sc. in Textile Engineer
Cell: +8801912-420118

Loop Length Control:
In a knitting m/c, V.D.Q. Pulley is used to supply the specific length of yarn. There are two or more adjustable pulleys which are known as V.D.Q. Pulley. By adjusting the V.D.Q. pulley we can control the speed of accumulator which supply the required amount of yarn. V.D.Q. pulley is very important to set up the correct loop length. The amount of yarn wound on accumulator by one revolution of cylinder is called the course length of fabric.
Fig: Passage Diagram of V.D.Q Pulley.
Course length= 1 × (A/B) × (C/D) × (E/F) × (G/H) × πd, Where d is the diameter of accumulator.

Course length =K × G

K = Constant = (A/B) × (C/D) × (E/F) × πd

K = Course length/ G

Course length =K X G

N × l = K × G

=>l = ( K× G) / n

= (K/n) × G

= MG   (M=K/n Which is fixed for a specific cylinder)

Sometimes, for a specific loop length, the required V.D.Q pulley is needed more or less than the numbered V.D.Q pulley value. For this condition, we have to change the constant value ‘k’. For change the ‘k’ we have to change E,F,E’,F’ gear.