Cotton is the most consumed material in natural fiber. It has a good hand touch, excellent water absorption, breathability, heat retention, and hard to charge. It is also characterized by good dyeability and strong strength on wet.
It is mainly used for everyday items that touch skin such as clothing and towels, T-shirts, jeans. Also, because cotton is a natural product, it contains inorganic substances such as pigment, lignin, pectin, cotton wax, metal content as primary contaminants. Removing those contaminants adequately will improve the quality (texture, coloring, water absorption) of the final product.In here, we introduce representative processing examples for each organization and solutions from NICCA CHEMICAL.
The greige cotton fabric includes sizing chemical such as starch, PVA wax etc. on warp yarn by preparation process before weaving, which are secondary contaminants. In the scouring process, these secondary contaminants and primary contaminants are mainly removed by continuous range.
In the scouring process of cotton fabrics, desizing by enzymes or oxidant then scouring then bleaching. This process is 3 stage.
Desizing and scouring together then bleaching, this process is 2stage.
On the other hand knit will make scouring, bleaching in a batch process at the same time.
Selection of scouring agent and prescription will be greatly affecting the quality of the final product according to the equipment etc.
Cotton knit is mostly dyed by reactive dyestuff after scouring and bleaching in the bath. Exhaustion ratio of reactive dye is about 60%. The disadvantage is highly impacted waste water by unexhausted dye and large amount of Glauber’s salt.
Cotton woven is generally dyed with continuous range. This is different from synthetic fabrics.
When dyeing is finished, removes unexhausted dyestuff on fiber surface by soaping after cold water rinse.
Soaping agents are required to remove unexhausted dyestuff from fibers and to prevent redeposition.
Although reactive dyes could obtain good wash fastness by removing unexthausted dyes on the fibers. However, due to the influence of humidity and temperature, the dye and fiber bonds are disconnected, so the fastness decreases with the over time. Fixatives are used to prevent this decrease in fastness and to prevent discoloration due to chlorine contained in tap water. Main component of fixatives is cationic polymer.
In general, medium to dark shade are used fixatives. Usage of fixatives is adjusted from color concentration.
It is the process of adding to hand feeling and functional performance for the final product.
Continuous pad process is common, required of finishing process is pad bath stability.
Functional property, such as add soft feelling, water repellent and quick dry.
Back to the Products Top