Monday 13 October 2008

Choice of Size Receipe



Choice of Size Receipe

The suitability of size receipe for the type of yarn should take into account, fabric construction, and end use as follows:

1. Cotton Yarn- Starch Based
Polyester etc.- Polyvinyl Alcohol (PVA) based

2. Fine and Superfine cotton- thin boiling Starches
Coarse Count- ordinary starch

3. Heavy Fabrics- Modified starches
Light and Medium- Ordinary starches

4. conventional sizing Machines- Low viscosity starch
High speed sizing machines- High viscosity starches

5. Unlbleached calendered sort of fabrics- More weighting agents, antiseptic softners etc. are used.
Bleached sorts- ordinary starches

6. Finer Counts and Heavier Constructions- More size pickups
Coarse counts- Less size pickups

7. Plied yarns- low size pick up or nil even

Ingredients for water Based Sizes

1. Adhesives- Potato starch, starch from cereals ( corn, wheat, rice etc0, carboxy methyl cellulose (CMC), Polyviny alcohol (PVA), Polyviny Chloride (PVC)

2. Lubricants- Mineral Waxes, vegetable waxes, animal fats, mineral oils, vegetable oils

3. Additives- Salicylic Acid, Zinc Chloride, Chloride emulsifiers.

Suggested Size Receipe

Ordinary starch=100
Gum= 2
Mutton tallow= 7.5

Preparation of Size Receipe

1. Ingredients

Water= 18.5"
Modified Starch = 50 kg
CMC= 5 kg
PVA= 10 kg
Gum = 1.5 kg
Softner= 1.2 kg
Antistat= 0.8 kg

Mixing: Took 17" water. Added Starch, Gum, CMC and PVA slowly and one by one as the slurry is stirred. Softner and antistat added in storage kettle.

Cooking

1. cold stirring at 50 rpm = 12 min
2. Transfer into pressure cooker through sieve=== 45 deg C
3. Stirrer rpm in cooker== 55
4. Close lid, open steam inlet, open air vent
5. Close air vent valve when steam is seen escaping through it, temperature = 96 deg C, Pressure = 10 PSI
6. time between point 3 and 4 == 15 min
7. Cooking starts, steam continued till temperature = 130 deg c, Pressure = 40 PSI
8. Time for getting 130 deg C after closing air vent valve = 25 min
9. Stem in-let closed
10. 10 minutes after closing steam, Temp= 124 deg C, Pressure = 32 PSI
11. Total cooking time after getting 130 deg C= 35 min
12. Flow time of paste taken through sample valve= 24 seconds
13. Transferred to storage beck
14. Final volume = 18.5 "
15. Stirrer RPM in storage beck = 20
16. Temperature after 10 min. of transfer = 100 deg C
17. Refrectometer reading= 16

Lab Data

1. Size add on = 18 %
2. Increase in strength % = 5.2
3. Elongation at break % os sized yarn = 6.8%



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