After weaving, refining, dyeing, finishing and other processing and treatment processes, the fabric is subjected to strong mechanical tension, and is prone to deformation phenomena such as weft contraction and warp elongation. If the deformed fabrics are used to process the garments, the deformation of the fabrics will be gradually recovered after ironing or washing, resulting in the deformation of the garments or the size of the garments become smaller and other problems. In order to make the fabric before processing to maintain a stable size and shape, must be pre-shrinkage of clothing materials before cutting to eliminate or ease the deformation of the fabric of a variety of adverse factors. Fabric pre-shrinkage is an important measure to ensure the quality of clothing, through the pre-shrinkage finishing can be sewn into the garment in the washing, ironing to maintain a stable shape and size.
1.Natural pre-shrinkage
For fabrics with small shrinkage rate, the fabrics should be disassembled and shaken before cutting, and then placed under tension-free condition for about 24 hours to make the fabrics shrink naturally and eliminate tension. For the lining and interlining materials can also be used in this way.
2. Wet pre-shrinkage
For larger shrinkage rate of fabrics or quality requirements of higher clothing, such as woven cotton and linen fabrics, cotton and linen fabrics, etc., the fabric can be soaked in water for a period of time, and then flattened and dried. For tweed fabrics, can use water spray ironing method of pre-shrinkage, ironing temperature can be controlled at about 160 ~ 170 ℃. For the shrinkage rate of large accessories can also be used in this way.
3. Heat pre-shrinkage
For some fabrics with large shrinkage under the action of temperature, dry heat pre-shrinkage can be used to moderate the thermal stress inside the fabric. Simple heat pre-shrinkage can be used directly with the surface of the fabric ironing iron contact heating, to achieve the effect of pre-shrinkage. Can also be used in the drying room, drying tube, oven, hot air or infrared radiation heat and other ways to pre-shrink.
4. Steam pre-shrinkage
This is a kind of wet heat pre-shrinkage method. Fabric in the steam to give wet and hot action to restore the yarn balance bending state, to achieve the purpose of pre-shrinkage, pre-shrinkage time can be decided according to the material properties, and then, through the drying or drying method of drying treatment.
In addition, the knitted fabrics of rolling and shaping, chemical fiber material stenter finishing, color fabrics desizing, rinsing, burning, sand washing and other finishing processes, can also play a natural pre-shrinkage effect.