Why does cotton fabric shrink

Update:12 Apr 2021

  Cotton has good moisture absorption, high moistu […]


Cotton has good moisture absorption, high moisture retention, good heat resistance, strong alkali resistance and sanitation are all the reasons why you are willing to buy cotton bedding. But many friends have such a question, "Why does cotton shrink?" So I summarized the relevant knowledge about cotton shrink, and now I will share it with you.

        1. The material of cotton

The quilt cover of pure cotton is composed of plant fibers. When the fabric is infiltrated, water molecules will enter the cotton fiber, causing the fiber to puff. When the weft direction (or warp direction) of the fabric puffs and becomes thicker, the fabric will shrink, so The longer the time in the water, the larger the shrinkage will be. Of course, this is only relatively speaking, and will not shrink endlessly.

   2. Textile processing

   In the process of textile dyeing and finishing of pure cotton fabrics, the fibers have to be stretched by a certain external force. After finishing, this stretching will temporarily stay in a "stable" state. When soaking and 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, dyeing and finishing, it needs to be stretched many times, and the shrinkage rate of the fabric with larger applied tension is larger, and vice versa.

  3. Yarn weaving of fabrics

Everyone should know that the yarn weaving of cotton bedding can be roughly divided into 1288*68, 130*70/13372/40 satin/60 satin/80 satin, etc. The higher the yarn woven, the more high-end fabrics, and the processing of the fabrics is not Same (such as pre-shrinking treatment or steam pre-shrinking, etc., to eliminate the potential for fabric shrinkage in advance. After pre-shrinking treatment, the fabric will generally not shrink again)

   4. Classification of fabrics

Commonly used cotton bedding can be roughly divided into four types: ordinary cotton four-piece suit, combed cotton four-piece suit, mercerized cotton four-piece suit, and brushed four-piece suit. The normal shrinkage rate can only be determined by personal luck. Generally speaking, the products of good manufacturers can be assured. Combed cotton and mercerized cotton are generally processed when they leave the factory, and the problem is not big. I can only say that the cheaper the brushing, the greater the shrinkage rate. Why is the same thing Inexpensive? Insufficient size, reduced post-processing procedures.

   5. The shrinkage rate of cotton

  For pure cotton fabric products, the national standard shrinkage rate is: less than or equal to 5% (that is, 95cm of 100cm fabric is normal after washing). After washing, pure cotton bedding should be stretched when it is about to dry. When the quilt is dry, it's useless to stretch it. If your quilt is really much bigger than the quilt, it’s useless to shrink. A normal pure brocade quilt is shrunk to 10cm, which is a standard 200*230 quilt, and the shrunk size is 190*220cm.

   6. The correct washing and maintenance of cotton

  Do not use hot water for washing. The water temperature must be controlled below 35°C. It cannot be soaked in detergent for a long time, ironed at a temperature higher than 120°C, cannot be exposed to the sun, or dried. Correct washing and drying should be done in a cool place. Use flat or round stick-type drying racks. Washing is best done by hand.

   Objectively speaking, all cotton fabrics have the problem of shrinking and fading. The key is the finishing. Therefore, the fabrics of general home textiles have been pre-shrinked. However, the pre-shrinking treatment does not mean that the shrinkage rate is controlled within 3%-4%% of the national standard.