Tension and Alkali removal of NaOH Solution.

Shenze County Cinye Textile is a professional manufacture of polyester and poly / cotton woven fabric. Our main products include twill fabric for Uniform Fabric poplin for pocketing fabric and shirt, T R baby twill for shirt, yarn dyed poplin and flannel for shirt, flannel fleece for blanket, canvas fabric and home textile artworks. 

1. Alkali solution concentration: main factors influencing the mercerizing effect
(1) change of length and diameter of cotton fiber after treatment with caustic soda solution of different concentrations: > 8% concentration, increase diameter and shorten length to the maximum
(2) shrinkage and dyeing force of cotton yarn in NaOH solution with different concentration
When C=177g/L, the barium value is 150, C=245g/ L, and the barium value is the highest.C=240~280g/l, and the contraction tends to be stable.
Therefore, the optimal caustic soda concentration of mercerizing is about 245g/l. Considering the alkali absorption of the fabric itself and alkali consumption of acidic gas in the air, the mercerizing alkali concentration of cotton cloth is 260 ~ 280g/l.In actual production, the quality of semi-finished products and finished products can be selected.
2, tension
(1) effect of tension on fabric luster: when cotton fabric is treated with concentrated alkali, only appropriate tension can be added to show a good sheen. From the effect of tension on the properties of cotton yarn after mercerization, it can be seen that: high tension and good gloss.
(2) effect of tension on fabric mechanical property and adsorption property: that is, in the condition of weakness, the strength of cotton yarn has been improved. If appropriate tension is applied, the strength can be further improved, but the gloss is not increased much, and the fracture elongation and adsorption property have declined.
(3) effect of tension on fabric shrinkage: when mercerizing, the warp and weft tension plays an extremely important role in fabric shrinkage.In actual production, the warp and weft shrinkage of various fabrics is unbalanced.For fabrics with higher warp density, such as khaki and iatu, the warp shrinkage greatly exceeds the zonal shrinkage, so the meridional tension is preferred.The opposite is true for thin fabrics such as plain cloth.

3, temperature,
The function of caustic soda and the cellulose fibre is exothermic reaction, so increase the temperature of the lye have weakened the effect of fiber swelling, thereby reducing mercerizing effects, performance on the shrinkage rate and barium value decreased, so the mercerizing alkali at low temperature is good, but given the economic benefits in the process of production, as well as the temperature is too low alkali liquor viscosity increases, make internal to the yarn and fabric, reducing fluid impermeable have enlarge picture is more difficult, so often used groove interlayer ventilation with cold water cooling of the lye.
4, time,
Mercerization is to make caustic soda quickly and evenly permeate into the inside of the cotton yarn or fabric and cause the fiber to act, so a certain time must be guaranteed.
The cotton yarn was mercerized with 280g/lNaOH under no tension. It was found that the yarn shrinkage and dye absorption rate reached the maximum at 20s, and the prolonged time had no significant effect on increasing mercerization.In addition, time is related to alkali concentration and temperature. When the concentration is low, the time should be extended appropriately.Generally adopt 50 ~ 60s.
5, to alkali
Alkali dealkali has a great influence on the finalizing effect of mercerization. If there is more than 5% alkali on the fabric after the tension is relaxed, the fabric will still shrink, thus affecting the gloss and zonal condensation rate.The process of alkali removal can be carried out in two steps: first, under the condition of amplification, the hot-dilute alkali leaching fabric will be washed with the suction device;After relaxing the zonal tension, stretch into the alkali removal chamber and steam with light alkali.