Sweater manufacturers believe that the process of using light’s complementary color principle to increase the crystal whiteness of textiles is called whitening finishing, also known as whitening. After bleaching textiles still contain yellowish substances, enhanced bleaching will damage the fibers. The use of brighteners can make blue and yellow complement each other, and can improve the whiteness of textiles when there is no damage to the fiber. There are two whitening methods: blue and fluorescence. The former applies a very light blue dye or pigment on the bleached fabric to offset the yellow color. Due to the increased absorption of light, the brightness of the fabric will be reduced and slightly darker. The fluorescent whitening agent is an organic compound with close to five colors. After being dyed on the fabric, it is excited by ultraviolet rays to produce blue and purple fluorescence, which complements the reflected yellow light and increases the whiteness and brightness of the fabric. The effect is better than that of blue. Fluorescent whitening can also be combined with bleaching, sizing or anti-wrinkle finishing in the same bath.
Calendering is a process that uses the plasticity of the fibers under humid and hot conditions to flatten the surface of the fabric or roll out parallel fine diagonal lines to enhance the luster of the fabric. The calender consists of a number of hard and soft rolls with smooth surfaces. The hard roller is a metal roller, the surface is highly polished or engraved with dense parallel lines, and a heating device is often attached. The soft roll is a fiber roll or a polyamide plastic roll. After the fabric is rolled by a combination of softer and soft rollers, the yarn is flattened, the surface is smooth, the luster is enhanced, and the hand feels stiff, which is called flat calendering. After the fabric is pressed by the combination of two soft rollers, the yarn is slightly flat, the luster is soft, the hand is soft, and the mineral b is soft calendering. Different gloss can be obtained by using different combinations of sodium smith rolls and changes in pressure, temperature and threading method. Calendering finishing is a mechanical treatment, and its fabric gloss effect is poor in durability. If the fabric is first dipped with resin shrinkage and pre-baked and stretched, a more durable gloss can be obtained after calendering.
The sweater factory believes that using the plasticity of the fiber, a pair of hard, soft, concave and convex rolls with a certain depth of pattern are used to press the fabric at a certain temperature to produce a concave-convex pattern effect. The process is called embossing. Also known as ginning finishing. The dyed or printed cotton or polyester/cotton blended fabric can form a durable embossing effect if the resin working fluid is impregnated in the embossing finishing. Synthetic fiber fabrics can be embossed directly after dyeing and printing. The process of embossing the fabric with a copper roller engraved with grooves as a hard roller and a high-elastic rubber roller with a flat surface as a soft roller is called embossing.
The process of using a sanding roller (or belt) to grind a layer of short and dense fluff on the surface of the fabric is called sanding finishing, also known as sanding finishing. The sanded fabric has the characteristics of being thick, soft and warm, which can improve the wearability of the fabric. Textured yarn or high shrinkage polyester knitted fabric or woven (shuttle) fabric can be made into a suede-like fabric after sanding. The base fabric with superfine synthetic fiber as raw material, through padding polyurethane emulsion and sanding, can obtain artificial suede with simulation effect. The effect of sanding (or sanding) finishing is similar to the principle of raising (or brushing), both of which produce fluff on the surface of the fabric. The difference is that metal card clothing is generally used for raising finishing (wool spinning also uses thorns), mainly the weft yarns of the fabric are raised, and the hairs are sparse and long. The velvet finishing can make the warp and weft yarns produce fluff at the same time, and the fluff is short and dense. For the velvet finishing, the strength of the fabric should be controlled, and its quality should be the short density and uniformity of the fluff as the main indicator.
In the process of dyeing and finishing, textiles are often deformed by wet heat treatment with various chemical auxiliaries and subjected to mechanical tension, and can cause stiffness and rough hand feeling. Soft finishing is a processing process that compensates for this defect and makes the fabric soft to the touch. There are two methods of soft finishing, mechanical and chemical. The mechanical method uses techniques such as pounding cloth to loosen the yarns or fibers to obtain a softening effect. The chemical method uses a softening agent to reduce the coefficient of friction between fibers to obtain a softening effect.
Different softeners adapt to different fibers and produce different softening effects and influence on other properties. Chemical methods are more commonly used, sometimes supplemented by mechanical methods.
The process of dipping the fabric with slurry and drying to obtain a thick and stiff effect is a finishing method for the purpose of improving the feel of the fabric. It uses a slurry made of a natural or synthetic polymer material with a certain viscosity to form a film on the fabric, so that the fabric has a smooth, stiff, thick, and plump feel, and improves its strength and abrasion resistance, and extends its service life. . Since the polymer material used in finishing is generally called slurry, it is also called sizing finishing. The stiffening slurry is mainly made up of slurry and a small amount of preservatives, and softeners, fillers or fluorescent whitening agents can also be added. According to the amount of sizing, there are light pulp and heavy pulp. The cotton fabric is impregnated with cellulose sodium zincate slurry, and then treated with dilute acid to coagulate the cellulose on the fabric, which can obtain a more wash-resistant and stiff linen-like finishing effect.
Weight gain finishing is a process that uses chemical methods to increase the weight of silk fabrics. In Europe in the 18th century, in order to compensate for the weight loss of real silk after scouring, a heavy finishing method was used to maintain commercial profits and use value. Weight gain finishing mainly includes tin weight method and tannin weight method. The proportion of silk fabrics finished by the tin-weighting method increases, the hand feels thick, smooth, the luster is rich, the drape is increased, and the shrinkage after moisture absorption is reduced. B treatment can increase the weight by 20% once, and the weight can be increased by 100% after repeated treatment. However, the strength, elongation and abrasion fastness of the silk fabric after weight gaining treatment are all reduced, and it is not good for storage, and it is more brittle and damaged after sun exposure. For example, after finishing, treated with soap or synthetic detergent to remove the tin salt attached to the surface, it can reduce embrittlement. The method of adding tannins is not suitable for the finishing of white and light-colored silk fabrics because the tannins turn black when meeting iron salts.
The sweater supplier believes that the weight reduction finishing is to use the hydrolysis of polyester fibers in a higher temperature and a certain concentration of caustic alkali solution to gradually dissolve the fibers and reduce the weight of the fabric (the weight loss is generally controlled at 20% to 25%), and the surface A number of depressions are formed to diffuse the reflected light on the fiber surface and form a soft luster. At the same time, the gap between the fibers in the yarn increases to form a silk style (appearance and feel) process, also known as weight reduction or alkali reduction Volume sorting. After finishing the polyester filament fabric, the luster is soft, light and soft, and the drape performance is greatly improved. It can be made into silk-like products such as georgette and crepe de chine. After finishing, the fabric of polyester staple fiber and its blended yarn and weft filament is smooth and smooth, and similar effects can be obtained.
At present, weight-reducing finishing mainly refers to reducing the weight of polyester fiber in the fabric. In fact, the partial dissolution of other fiber fabrics with appropriate chemical crystals also belongs to the category of weight reduction finishing. For example, polyester and cotton or viscose blended fabric, treated with a cold sulfuric acid solution of more than 65%, will completely corrode the cotton or viscose, and also make a significant change in the style of the product. This kind of weight reduction is customarily called acid weight reduction.