The process by which the yarn or fiber is elongated by passing
it through a series of pair of rollers, each pair moving faster than the
previous one is called drawing. It is a system which removes stable/weak and brittle
properties of filaments.
Objects of drawing/stretching:
1. To increase strength.
2. To reduce creepe properties
3. To increase orientation and crystallinity
4. To remove brittleness
Condition of drawing: Three factors are considered for
drawing:
1. Drawing ratio: During drawing the ratio of speed of front
roller to the back roller is called drawing ratio.
Drawing
ratio = (V2/V1) ; where, V2>V1
2. Draw temperature
3. Draw speed:
A
|
8.4m/min
|
B
|
36
m/min
|
C
|
116
m/min
|
D
|
170
m/min
|
E
|
258
m/min
|
