What are the post-processing technologies of jeans?

Jeans are usually washed with the following basic technological processes: hand sewing, edge grinding, desizing, fermentation, chlorine bleaching, dechlorination and dehydration, drying, washing with potassium permanganate and oxalic acid, dyeing and dehydration, drying, resin spraying, scraping, drying and subsequent finishing.

1 bottoming process

Background painting usually includes hand sewing, edge grinding, desizing, enzyme washing and grinding, chlorine bleaching, spraying potassium permanganate and oxalic acid.

1. 1 Hand sewing and hemming

Sewing/hand sewing process is to use daily manual needles, and try to use thinner threads to avoid leaving larger pinholes after washing; Hand sewing is an attractive, effective and safe crease replacement process. Because wrinkles need to be treated with resin and high temperature, resin is easy to damage yarns, and improper treatment is easy to cause clothes to break and damage during wearing; Hand sewing only needs to sew the position that needs wrinkle effect with manual needle and thread before washing water. After washing, the wrinkle position will also have a natural washing effect and wrinkle effect, so don't worry about breaking it, because there is no need to use resin to shape it. SPAN & gt

Edge grinding is the first consideration in washing jeans. If hand sewing is needed, it should be done after desizing and fermentation grinding, and edging should be done before desizing or after dyeing.

1.2 desizing

Desizing is the process of removing the size from the fabric with clear water. Most warp yarns of cotton, viscose and synthetic fibers are sized before weaving. Size will affect the wettability of fabric in dyeing and finishing process, and hinder the contact between chemicals and fibers. So fabrics are generally desized first. Desizing process conditions: 50-60℃, 65438 00 minutes.

Pay special attention to the problem of blisters when desizing, that is, to avoid stripes and water marks. When this crease passes through post-fermentation grinding, it is particularly easy to be damaged due to the friction between pants, between pants and enzyme, and between pants and washing machine, forming white marks!

Solution: the speed of the washing machine should be high, and the clothes can't be thrown away if it is too low; There should not be too many clothes, and there should be enough rolling space; Use lubricant.

1.3 expander

The methods of fermentation grinding can be cellulase grinding, biological enzyme grinding, stone grinding (dry grinding) and so on. Among them, biological enzyme grinding and washing, also known as wet grinding, is a special cellulase fermented by non-pathogenic microorganisms in water. Cellulase is an enzyme that can degrade fibers. The process of action on cellulose is firstly enzyme adsorption, and then cellulose begins to hydrolyze. Enzyme molecules cannot penetrate into the fabric, and hydrolysis only occurs on the surface of the fabric. The specific process conditions depend on the wear degree of jeans required by the order. Generally, the dosage of biological enzyme is about 100g, 40-50℃, 15 min.

The general dosage of cellulase milling is about 100g/ machine, and the temperature is generally about 50℃. The specific time depends on the wear degree of jeans required by the order. If the action time of cellulase is prolonged too much, the fabric will be damaged or even worn. Compared with pumice mill, the old jeans washed by cellulase are softer, shallower in apparent depth, whiter and brighter, and the strength of all parts of the clothing drops evenly, without fluff, smooth in surface and partially damaged.

The outstanding advantage of cellulase milling and washing is that it is particularly easy to wash, unlike stone mill washing, which is extremely difficult to wash, and it makes the pattern delicate, the white part is not gray, the drape is greatly increased, and the wearing comfort is greatly improved. It is an upgrading process instead of stone mill washing. Its functions are as follows: (1) Cellulase has an imitation effect on cellulose fabrics printed and dyed by any process; It can reduce the weight of cellulose fabric and has a permanent soft feeling; The drape of the fabric is greatly increased, the feel is heavy, and the surface will produce fluff, so that the product has a warm feeling and attractive luster; It can remove dead cotton and neps and make the cloth surface smooth. The grain of twill fabric is clearer and the concave-convex feeling is obviously increased; Denim fabrics do not need to be washed by stone mill, and the style of denim washed by stone mill can make sodium hypochlorite not fade.