Introduction
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Alkali (caustic or soda ash) is used in processing almost all cotton products.
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Alkali sticks to cotton (like a magnet).
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The cost of the water, energy and time needed to remove all the alkali is significant.
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Residual alkali is one of the major causes of quality problems in cotton products.
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Some experiments were run to demonstrate the problem and the importance of thorough rinsing or neutralization.
Resin Formulation |
| Component |
% OWB* |
| Wetting Agent (10% Solution) |
0.73 |
| DMDHEU Resin |
8.72 |
| Catalyst |
2.18 |
| Polyethylene Softener (Cationic) |
2.18 |
| Aminofunctional Silicone |
2.18 |
| *OWB, On Weight of Bath, WPU - 90% |
Process Conditions |
| Spray on chemicals |
| Tumble for 30 minutes for equilibraion |
| Tumble dry to low moisture (10-15%) |
| Press |
| Cure at 300F (149C) for 15 minutes |
Fabric Alkalinity |
| Total, % |
| Sample ID |
Alkalinity (%), Total |
| Control |
0.063 |
| Padding 1 |
0.150 |
| Padding 2 |
0.190 |
| Padding 3 |
0.340 |
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FABRIC PHYSICAL PROPERTIES |
| Resin Finished |
| |
Tensile |
Tear |
Flex |
|
|
| Sample ID |
Warp |
Fill |
Warp |
Fill |
Warp |
Fill |
Crease |
DPRating |
| Control, No Resin |
165.8 |
111.0 |
4.5 |
5.0 |
287 |
370 |
N.M.* |
N.M. |
| Control, With Resin |
71.4 |
51.8 |
3.9 |
3.9 |
191 |
366 |
2.6 |
3.0 |
| Padding 1 |
92.2 |
54.0 |
5.2 |
5.0 |
263 |
342 |
3.0 |
3.2 |
| Padding 2 |
89.6 |
62.4 |
5.1 |
5.3 |
1369 |
727 |
2.3 |
3.0 |
| Padding 3 |
112.8 |
74.1 |
6.4 |
7.1 |
3471 |
1905 |
1.4 |
2.0 |
| *N.M. = Not Measured |
FABRIC WHITENESS vs. ALKALINITY |
| Sample ID |
Alkalinity, % NaOH |
CIE Whiteness |
| Control, No Resin |
0.063 |
78.3 |
| Control, No Resin (Cured) |
0.063 |
69.6 |
| Control, With Resin |
0.063 |
68.1 |
| Padding 1 |
0.150 |
63.4 |
| Padding 2 |
0.190 |
64.5 |
| Padding 3 |
0.340 |
59.9 |
|
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