Saturday, 11 October 2008
Process Control in Sizing-1
The process consists of laying warp yarn parallel and sizing the yarn with a mixture to strengthen it to withstand the rigours of weaving.
Warp yarn is withdrawn in sheet from from warp beams which are placed at the back of the sizing machine. The yarn is then passed through sow box. Size solution is applied by immersion. After removing surplus solution that occurs at this state, the yarn is dried and arranged on a loom beam.
The objective of sizing is RESISTANCE to ABRASION
This objective is achieved by applying on the yarn a unifrom and smooth protective film of suitable sizing material.
We also want that in the sized yarn there should be
- Some increase in tensile strength in the yarn
- Minimum loss of extensibility in yarn ( about 4.4-4.6% elongation at break is required for cotton)
-Required moisture content ( 8-10% of cotton)
- Good quality of sized beam (neither too soft nor too firm + free from yarn defects)
- Good productivity and efficiency
- Reduced Cost
Process Control in Sizing
The process control programme in sizing should, therefore, comprise of the following aspects:
1. Selecting the correct size receipe and size pick -up level
2. Ensuring correct preparatio of size paste
3. Control of
- size pick up
-quality of beam
-a method to calculate the expected level of productivity