Post-finishing is a technical treatment method that gives fabrics color effects, shape effects (smooth, suede, crisp, etc.) and practical effects (impermeable, non-felting, non-ironing, non-wormy, flame-resistant, etc.). Post-finishing is a process that uses chemical or physical methods to improve the appearance and feel of fabrics, enhance wearing properties or give special functions. It is the “icing on the cake” of textiles.
Post-finishing methods can be divided into two categories: physical/mechanical finishing and chemical finishing. According to the purpose of post-finishing and the effects produced, it can be divided into basic finishing and appearance finishing. and functional organization.
Purpose of post-finishing:
1. Make the textile width uniform and the size and shape stable . Such as (stretching), mechanical or chemical anti-shrinkage, anti-wrinkle and heat setting, etc.
2. Improve the appearance of textiles: including improving the gloss and whiteness of textiles, and enhancing or weakening the fluff on the surface of textiles. Such as whitening, calendering, electro-optical, subtext, sanding, shearing and shrinking, etc.
3. Improve the feel of textiles: Chemical or mechanical methods are mainly used to make textiles obtain comprehensive touch feelings such as soft, smooth, plump, stiff, light or thick. Such as softness, stiffness, weight gain, etc.
4. Improve the durability of textiles: Chemical methods are mainly used to prevent damage or erosion of fibers by sunlight, atmosphere or microorganisms, and extend the service life of textiles. Such as moth-proofing, mildew-proof finishing, etc.
5. Giving textiles special properties: including giving textiles some protective properties or other special functions. Such as flame retardant, antibacterial, water repellent, oil repellent, UV protection and antistatic, etc.
The development of fabric finishing technology is developing towards product functionality, differentiation, high-end, diversification and depth of processing technology, and emphasizes improving The taking performance of the product increases the added value of the product. In recent years, various new technologies (such as low-temperature plasma processing, bioengineering, ultrasonic technology, electron beam radiation processing, inkjet printing technology, microcapsule technology, nanotechnology, etc.) have been continuously introduced and borrowed from other technical fields to improve processing Depth to get a good finishing product. As humans pay more and more attention to environmental pollution and damage, they pay more and more attention to health, and advocate a “low-carbon” economy. Post-finishing technology requires environmentally friendly “green” processing to produce “clean” and “low-carbon” textile products.
The basic finishing methods of fabrics are: finishing methods to stabilize size and improve appearance, finishing methods to improve hand feel and optimize performance, and finishing methods to make fabrics multifunctional and high added value. , finishing methods to make fabrics more advanced, and finishing methods to meet special requirements.
Various finishing processes are as follows:
1 Pre-shrinking
Preshrinking is a process that uses physical methods to reduce the shrinkage of fabrics after being soaked in water to reduce the shrinkage rate. Mechanical preshrinking means that the fabric is first wetted by steam or spray, and then mechanically squeezed in the warp direction to increase the buckling wave height, and then dried by loosening.
2 Tenting
Tentering uses cellulose and silk Due to the plasticity of fibers such as wool and wool under humid conditions, the width of the fabric is gradually widened to a specified size for drying, so that the shape of the fabric can be stabilized. It is also called finishing.
3 Sizing
Sizing means that the fabric is dipped in slurry and dried Finishing process that results in a thick and stiff feel.
4 Heat setting
Heat setting It is a process that makes the shape of thermoplastic fibers and blends or interwovens relatively stable. It is mainly used for the processing of synthetic fibers such as nylon or polyester and their blends that are prone to shrink and deform after being heated. Heat-set fabrics can improve dimensional stability and have a stiffer feel.
5 Whitening
Whitening is the use of the principle of complementary colors of light The process of increasing the whiteness of textiles is also called whitening. There are two whitening methods: bluing and fluorescent whitening.
6 Calendering, electropolishing and embossing
Calendering is A process that uses the plasticity of fibers under hot and humid conditions to flatten or roll out parallel fine twills on the surface of the fabric to enhance the luster of the fabric. Flat calendering is a hard rolling point composed of a hard roller and a soft roller. After the fabric is rolled, the yarn is flattened, the surface is smooth, the gloss is enhanced, and the feel is stiff. Soft calendering is a soft calendering point composed of two soft rollers. After the fabric is calendered, the yarn is slightly flat, with a soft luster and a soft feel.
Electro-optical calendering uses electrically heated rollers to calender the fabric.
Rolling is a rolling point composed of a steel roller engraved with a positive pattern and a soft roller. Under hot rolling conditions, the fabric can obtain a lustrous pattern.
7 Sanding and sanding
Use a sanding roller ( (or belt) The process of grinding a layer of short and dense velvet on the surface of the fabric is called sanding, also known as sanding. Sanding finishing can make the warp and weft yarns produce velvet at the same time, and the velvet is short and dense.
8 Fluffing
Raising is a process in which dense needles or thorns are used to pick up the fibers on the surface of the fabric to form a layer of fluff. It is also called brushing. Raising is mainly used for woolen wool fabrics. , acrylic fabrics and cotton fabrics, etc. The pile layer increases the warmth of the fabric, improves its appearance and makes it feel soft.
9 Shearing
Shearing is a process in which a shearing machine is used to remove unwanted hair on the surface of the fabric. Its purpose is to make the fabric texture clear and the surface smooth, or to make the pile or suede surface of raised or raised fabrics neat. Generally, products such as wool, velvet, artificial fur, and carpets require shearing.
10 Softness
Softening finishing includes mechanical finishing and chemical finishing. In this method, mechanical softening is achieved by rubbing and bending the fabric multiple times, but the softening effect after finishing is not ideal. Chemical softening finishing is to apply softening agent to the fabric to reduce the friction coefficient between fibers and yarns, thereby obtaining a soft and smooth feel, and the finishing effect is significant. </p
