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 |
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