EXPERIMENT 3: STUDY ON V.D.Q PULLEY.

MACHINE PARAMETERS 1. V.D.Q Pulley. 2 Machine Gauge3 Machine Diameters.4. Needle Gauge.

1. V.D.Q Pulley

VDQ pulley (Variable Dia for Quality Pulley): It is a very important part of the machine. It controls the quality of the product. Altering the position of the tension pulley changes the G.S.M. of the fabric.

Fig.VDQ Pulley

If pulley moves towards the positive directive then the G.S.M. is decrease. And in the reverse direction G.S.M will increase.

Pulley Belt: It controls the rotation of the MPF wheel.

Brush: Its clean the pulley belt.

V.D.Q pulley is a pulley which drives several smaller pulleys by a tooted belt. These smaller pulleys are at the driven position and drive a clutch device which engages

V.D.Q pulley constant There is a relation of V.D.Q number, stitch length and needle number. It is, Constant,

Kv =This constant is dependent mainly on the M/C. Different machine type, brand; diameter can vary the value of the constant. For a given machine the constant is same. For Single jersey fabric the V.D.Q pulley constant is 41.20825 & for Rib fabric the V.D.Q pulley constant is 68.76084. With these values a better selection of VDQ number can be obtained for a particular stitch length. VDQ pulley is control the GSM of stitch. The main function of VDQ pulley is increase and decrease of the GSM. If the single jersey GSM 120-130 it’s for needed 30/32 Ne yarn.

2. Machine Gauge

No. of needles per inch present in a needle bed of a knitting machine is called machine gauge for that knitting machine. Selection of machine gauge depends upon the following: Yarn count, Fiber type, Yarn twist, Yarn finished.

3. Machine Diameter

Machine diameter is mainly diameter of m/c cylinder. It is important for fabric width. Only diameter does not fetermi-with the yarn wheel. By varying the dia of the V.D.Q pulley, which is at the driver position, the amount of the yarn feeding can be controlled. This variation in the yarn feeding varies the stitch length and the G.S.M.

V.D.Q a Stitch length (when needle is same)

V.D.Q a No. of Needle (when stitch is same)

From the above two expression we get, V.D.Q a Stitch length X Needle

Constant, Kv=

This constant Kv varies with the diameter of the machine, type of the machine (single or double jersey), different brand of machines.

4. Needle Gauge

Thickness of needle express by the needle gauge. It is important for selection of machine gauge