Why does cotton shrink? Why is it normal for fabrics to shrink?

Pure cotton fabric is composed of plant fibers. When the fabric is soaked, water molecules will enter the interior of the cotton fiber, causing the fibers to expand. When the weft (or warp) direction of the fabric expands and becomes thicker, the fabric will shrink. Therefore, the longer it is immersed in water, the greater the shrinkage will be. Of course, this is only relative, and it will not shrink endlessly.

During the dyeing and finishing process of pure cotton fabrics, the fibers are stretched by a certain external force. After finishing, this stretching will be temporarily in a “stable” state. When cleaning in water, the moisture will gradually weaken the connection between fiber molecules, reduce the friction on the fiber surface, destroy the temporary “stable” state, and the fiber will return to or be close to its original state.� Equilibrium state. Generally speaking, during the weaving, dyeing and finishing process, it needs to be stretched many times. The fabric with greater tension will have a greater shrinkage, and vice versa.

Everyone should know that the yarn weave of Cotton bedding 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 quality of the fabric, and the processing of the fabric is also Different (such as pre-shrunk treatment or steam pre-shrinking, etc., the potential of fabric shrinkage is eliminated in advance, and the fabric will generally not shrink significantly after pre-shrinking treatment).

Commonly used Cotton bedding can be roughly divided into four types: general Cotton four-piece set, combed cotton four-piece set, silk finished cotton four-piece set, and brushed four-piece set. The general shrinkage rate can only depend on personal luck. , Generally speaking, you can rest assured about the products of good manufacturers. Combed cotton and silk-finished cotton are generally processed before leaving the factory, and the problems are not big. Regarding sanding, I can only say that the cheaper the product, the greater the shrinkage. The same Why are things cheap? Insufficient size and reduced post-processing steps.

For pure cotton fabric products, the national standard shrinkage rate is: less than or equal to 5% (that is: 100cm of fabric is normal after washing). Pure cotton bedding should be stretched when it is about to dry after washing. . Once the quilt cover is dry, stretching is useless. If your quilt cover is really much larger than the quilt core, shrinking it is useless. A general pure cotton quilt cover shrinks to 10cm, which is a standard 200*230 quilt cover. The shrunk size is 190*220cm.

Do not use hot water for cleaning. The water temperature should be controlled below 35°C. It cannot be soaked in detergent for a long time, ironed at a temperature higher than 120°C, exposed to the sun, or dried. Proper cleaning and drying should be carried out in a cool place. Lay it flat or use a stick-shaped drying rack. It is best to wash it by hand.

Objectively speaking, Cotton fabrics have some shrinkage and fading problems. The key is post-processing. Therefore, most home textile fabrics have been preshrunk. However, pre-shrinking does not mean that it does not shrink, but it means that the shrinkage rate is controlled within the national standard 3%-4%%.