Why does cotton shrink?

One: cotton material

The pure cotton fabric is composed of plant fibers. When the fabric is infiltrated, water molecules will enter the cotton fiber, causing the fiber to expand. The longer the time in the water, the larger the shrinkage. Of course, this is only relative, and it will not shrink endlessly.

Two: Textile processing

During the textile dyeing and finishing process of pure cotton fabrics, the fibers are stretched by a certain external force. After finishing, this stretch will temporarily be in a "stable" state. When soaking in water for washing, the water will gradually weaken the connection between fiber molecules, reduce the frictional force on the fiber surface, and destroy the temporary "stable" state, and the fiber will return to or approach the original equilibrium state. Generally speaking, in the process of weaving, weaving and dyeing and finishing, it needs to be stretched many times, and the shrinkage rate of the fabric with higher tension is larger, and vice versa.

Three: 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 and so on. The same (such as pre-shrinking treatment or steam pre-shrinking, etc., to eliminate the potential of fabric shrinkage in advance, after the pre-shrinking treatment, the fabric will generally not have a large shrinkage).

Four: classification of fabrics

Commonly used cotton bedding can be roughly divided into four types: ordinary cotton four-piece sets, combed cotton four-piece sets, mercerized cotton four-piece sets, and sanding four-piece sets. The ordinary shrinkage rate can only depend on personal luck. Generally speaking, good manufacturers' products can be assured. Combed cotton and mercerized cotton are generally treated when they leave the factory, and the problem is not big. Regarding sanding, I can only say that the cheaper the shrinkage, the greater the shrinkage. Why is the same thing? Cheap? Insufficient size and reduced post-processing steps.

Five: 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, the pure cotton bedding should be stretched when it is about to dry. When the quilt is dry, it is useless to stretch it. If your quilt cover is really much bigger than the quilt, shrinking is useless. The general cotton quilt cover shrinks to 10cm, which is a standard 200*230 quilt cover, and the shrunk size is 190*220cm.

Six: the correct washing and maintenance of cotton

Do not use hot water for washing, the water temperature should be controlled below 35°C, it should not be soaked in detergent for a long time, and it should not be ironed at a temperature higher than 120°C, and it should not be exposed to the sun or dried. Correct washing and drying should pay attention to the shade, use flat laying or use a garden stick-type drying rack, and washing is best done by hand.

Epilogue

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, pre-shrinking treatment does not mean no shrinkage, but means that the shrinkage rate is controlled within the national standard 3%-4%%.