Post-finishing is a technical treatment method that endows fabrics with color effect, morphological effect (smooth, textured, crisp, etc.) and practical effect (impervious to water, non-felting, non-ironing, non-moth, flame resistance, etc.). Post-finishing is a technological process that improves the appearance and feel of fabrics, enhances wearability or endows special functions through chemical or physical methods, and it is the processing process of textile "icing on the cake".

The purpose of post-finishing

Post-finishing methods can be divided into two categories: physical/mechanical finishing and chemical finishing, which can be divided into basic finishing, appearance finishing and functional finishing according to the purpose and effect of post-finishing. The purpose of finishing:

1. make the width of textile uniform and stable in size and shape. Such as setting (stretching) width, mechanical or chemical shrinkage prevention, wrinkle prevention and heat setting, etc.

2. Improving the appearance of textiles: including improving the luster and whiteness of textiles and strengthening or weakening the surface fluff of textiles. Such as whitening, calendering, electro-optic, sub-culture, sanding, shearing and shrinking.

3. Improve the hand feeling of textiles: mainly use chemical or mechanical methods to make textiles obtain comprehensive touch feeling such as softness, smoothness, fullness, stiffness, lightness or thickness. Such as softness, stiffness and weight gain.

4. Improve the durability of textiles: mainly adopt chemical methods to prevent the damage or erosion of fibers caused by sunlight, atmosphere or microorganisms, and prolong the service life of textiles. Such as moth-proofing and mildew-proofing finishing.

5. Giving textiles special properties: including making textiles have certain protective properties or other special functions. Such as flame retardance, antibiosis, water repellency, oil repellency, ultraviolet protection and antistatic property.

The development of fabric finishing technology is towards the functional, differentiated, high-grade products, and diversified and deep processing technology, with emphasis on improving the wearability of products and increasing the added value of products. In recent years, various new technologies (such as low-temperature plasma treatment, bioengineering, ultrasonic technology, electron beam radiation treatment, ink-jet printing technology, microcapsule technology, nano-technology, etc.) have been continuously introduced from other technical fields to improve the processing depth and obtain good finishing products. With the concern about environmental pollution and destruction, people pay more and more attention to health, and advocate "low-carbon" economy. The finishing technology requires environmental protection and "green" processing to produce "clean" and "low-carbon" textile products.

The basic finishing methods of fabrics include: stabilizing size, improving appearance, improving hand feeling optimization, making fabrics multifunctional and with high added value, making fabrics advanced, and meeting special requirements. Various finishing processes are as follows:

01 preshrinking Pre-shrinking is a technological process to reduce shrinkage of fabrics after soaking in water by physical methods. Mechanical preshrinking is to wet the fabric by steam spraying or spraying, and then apply mechanical extrusion in the warp direction to increase the buckling wave height, and then dry it loosely.

02 tentering Tenting is a technological process that makes use of the plasticity of cellulose, silk, wool and other fibers under wet conditions, and gradually broadens the fabric width to the specified size for drying, so as to stabilize the fabric shape, which is also called sizing finishing.

03 sizing Sizing refers to the finishing process in which the fabric is dipped with slurry and dried to obtain a thick and stiff hand feeling.

04 heat setting Heat-setting is a technological process that makes thermoplastic fibers and blends or interwoven fabrics relatively stable. It is mainly used for processing synthetic fibers such as nylon or polyester and their blends which are easy to shrink and deform after being heated. Heat-set fabrics can improve dimensional stability and feel stiff.

05 whitening Whitening is a technological process of increasing the whiteness of textiles by using the complementary color principle of light, also known as whitening. There are two whitening methods: bluing and fluorescent whitening.

06 calendering, electro-optic and embossing Calendering is a technological process that uses the plasticity of fiber under wet and hot conditions to flatten the surface of fabric or roll out parallel fine twill, so as to enhance the luster of fabric. Flat calendering is a hard rolling point composed of a hard roll and a soft roll.

After the fabric is rolled, the yarn is flattened, the surface is smooth, the luster is enhanced, and the hand feel is stiff. Soft rolling is a soft rolling point composed of two soft rolls. After the fabric is rolled, the yarn is slightly flat, with soft luster and soft hand feeling. Electro-optic is the use of electrified rollers to polish fabrics. Rolling grain is a rolling point composed of steel roll and soft roll engraved with embossed pattern. Under hot rolling condition, the fabric can obtain shiny pattern.