Textile knowledge——Why does cotton fabric shrink

Cotton has better hygroscopicity, higher moisture retention, good heat resistance, stronger alkali resistance and hygienicity, which are the reasons why you are willing to buy cotton bedding. As for the cotton that everyone cares about, will it shrink? The answer is yes. But why does cotton shrink? Do you know?

　　Cotton material

　　The fabric of pure cotton is composed of plant fibers. When the fabric is infiltrated, the water molecules will enter the inside of the cotton fiber, causing the fiber to expand. When the weft (or warp) of the fabric expands and becomes thick, the fabric will shrink, so the impregnation The longer you stay in the water, the shrinkage will be relatively larger. Of course, this is only relatively speaking, and will not shrink endlessly.

　　Textile processing

　　In the process of dyeing and finishing of pure cotton fabrics, the fibers must be stretched by a certain external force. After finishing, this stretching will temporarily be in a "stable" state. When immersed in water for washing, the moisture will gradually weaken the connection between the fiber molecules, the friction on the fiber surface will be reduced, and the temporary "stable" state will be destroyed, and the fiber will return to or close to the original equilibrium state. Generally speaking, in the process of weaving, weaving, dyeing and finishing, it needs to be stretched many times, and the shrinkage rate of the fabric with large applied tension is large, and vice versa.

　　Fabric weaving

　　Everyone should know that the yarn weaving of cotton bedding products can be roughly divided into 1288*68, 130*70/13372/40 satin/60 satin/80 satin, etc. The higher the yarn weave, the higher the fabric, and the treatment of the fabric. The same (such as pre-shrinkage treatment or steam pre-shrinkage, etc., to eliminate the potential for shrinkage of the fabric in advance, after the pre-shrinkage treatment, the fabric generally will not have larger shrinkage).

　　Fabric classification

　　Commonly used cotton bedding can be divided into four types: ordinary cotton four-piece set, combed cotton four-piece set, mercerized cotton four-piece set, brushed four-piece set, ordinary shrinkage rate can only be seen by personal luck, Generally speaking, a good manufacturer's products can still be assured. Combed cotton and mercerized cotton are generally processed at the factory, and the problem is not big. I can only say that the cheaper the shrinkage rate is, the more the same thing. Cheap? Insufficient size reduces the post-processing process.

　　Shrinkage of cotton

　　For cotton fabric products, the national standard shrinkage rate is: less than or equal to 5% (that is, 95cm is normal after 100cm fabric is washed). After washing the cotton bedding, it will be dried when it is about to dry. When it is entangled, it will be useless. If your quilt is really much larger than the quilt, shrinkage is useless. The general cotton quilt cover shrinks to 10cm, which is a standard 200*230 quilt. The size after shrinkage is 190*220cm.

　　Correct washing and maintenance of cotton

　　Do not use hot water for washing, the water temperature should be controlled below 35 ℃, can not be soaked in the detergent for a long time, cannot be ironed at a temperature higher than 120 ℃, can not be exposed to the sun, and can not be dried. Proper washing and drying should be paid attention to in a cool place, using a tile or a garden stick type drying rack. Washing is best done by hand.

　　Conclusion

　　Objectively speaking, the problem of shrinking and fading of cotton fabrics is more or less. The key is the finishing. Therefore, the fabrics of home textiles have been pre-shrinked. But after pre-shrinkage treatment does not mean not shrinkage, but means that the shrinkage rate is controlled within 3%-4%% of the national standard.