Denim is a garment that can be worn all year round and has been loved by consumers since its birth. It is different from casual pants. The fabric of jeans needs to be washed before wearing. Therefore, washing is an important process in making denim. So, what are the washing processes for denim? Xiao E will help everyone understand.
Common denim washing process
1
GARMENT WASH
General washing is ordinary washing. It just changes the washing we are familiar with to mechanization. The water temperature is about 60°-90°C. Add a certain amount of detergent. After about 15 minutes of ordinary washing, Just add softener to clean water to make the fabric softer, more comfortable, and visually more natural and cleaner. Usually, based on the length of washing time and the amount of chemicals used, general washing can be divided into light general washing, general washing and heavy general washing. Usually light general washing lasts about 5 minutes, general washing lasts about 15 minutes, and heavy general washing takes about 30 minutes (the time is not precise). There is no obvious boundary between the three washing methods.
2
Stone wash/stone grinding (STONE WASH)
Stone washing is to add a certain size of pumice stone to the washing water to polish the pumice stone with the clothes. The water level in the polishing tank is set to a low level where the clothes are completely soaked, so that the pumice stone can be in good contact with the clothes. General washing or rinsing can be carried out before stone grinding, and rinsing can also be carried out after stone grinding. According to the different requirements of customers, yellow stone, white stone, AAA stone, artificial stone, rubber balls, etc. can be used for washing to achieve different washing effects. After washing, the cloth surface will appear gray and old, and the clothes will be slightly to severely damaged. .
Stonewash: Stonewash uses physical methods to fade denim and increase the color contrast. Put a roll of cloth 20 yards long and 62 inches wide into a 250-pound washing tank with pumice stone for stone washing (the washing effect is best when it accounts for 35% of the tank capacity). Denim and stones are mixed and tumbled in the washing tank, rubbing against each other. The length of the tumbling time determines the depth of the color of the denim after washing. The longer the washing time, the lighter the color and the stronger the color contrast. After denim is washed, it is rinsed, softened and dried.With its softness and rich colors, denim has become the fashionable fabric of choice for the home textile and clothing industries.
3
Enzyme Wash (ENZYME WASH)
Enzyme is a kind of cellulase, which can degrade the fiber structure at a certain pH value and temperature, so that the cloth surface can fade and lose hair (producing a “peach skin” effect), and Get long-lasting softness. Stones can be used together with or in place of stones. If used together with stones, it is usually called ENZYME STONE WASH.
Enzyme washing: Enzymes, like enzymes, can be used to degrade cellulose in cotton fibers. Since the color of denim is actually attached to the outer layer of the yarn, through enzyme washing, the fiber and the indigo dye attached to it can be washed away. When the desired color is obtained, the enzyme wash can be stopped by changing the alkalinity of the water or raising the water temperature. Then proceed to the next step of rinsing and softening. Enzyme washing is gentler than stone washing because no sharp-edged stones are used in the enzyme washing process. Enzyme-washed denim has uniform color and soft feel, and is suitable for home textiles and clothing.
4
SAND WASH
Some alkaline and oxidizing additives are often used in sand washing to make the clothes have a certain fading effect and a sense of staleness after washing. If it is combined with stone grinding, a layer of soft frosty white fluff will be produced on the surface of the cloth after washing, and then add Some softeners can make fabrics softer and softer after washing, thereby improving wearing comfort.
Sand washing: This post-finishing process uses a row of horizontally placed rollers, which can be wrapped with sandpaper or chemically treated abrasives. The denim is put on a roller and the bulges are frosted. This finishing method will partially fade the denim and create a velvet feel on the surface of the denim, giving it a soft, delicate feel. The sand washing treatment method can also produce fashionable appearance effects such as wrinkles and whiskers on denim.
(1) Sand washing agent
a) Bulking agent: According to the type of fiber , the puffing agent and concentration, temperature, time and other puffing conditions are selected according to the structure and tightness of the fabric. Sand washing of pure cotton clothingAlkaline puffing agents such as soda ash can be used for puffing treatment.
b) Sand detergent: After the clothes are puffed, the fibers are loosened, and then special sand washing is used for friction to make the loose surface fibers plump and soft. In order to make the suede full, sand powders of different shapes and hardnesses must be used. For example, diamond-shaped sand (to make the loose fibers produce fluff), polygonal sand (to make the fluff stand upright), and round sand (to make the fluff full) can be used. ).
c) Softener: Softener used for sand washing. It is required to be soft and waxy, so that the fabric can gain weight and the drape should be significantly improved. Therefore, this type of softener should have a long carbon chain and be cationic, so it can be adsorbed on the fabric to achieve the purpose of weight gain.
(2) Sand washing equipment
At present, industrial water washing machines are generally used for puffing , sand washing and softening treatment, using a centrifugal pump dehydrator to dehydrate, and drying using a rotary drum dryer used in knitting factories to dry goose down.
(3) Sand washing process
Cotton clothing can determine the type, dosage, temperature and time of the bulking agent, as well as the dosage of sand washing powder and softener, as well as the processing temperature and time, based on the tissue structure, warp and weft density, yarn count thickness, and twist strength. Generally speaking, the sand washing effect of yarn fabrics is better than that of line fabrics, coarse count yarns are better than high count yarns, low twist is better than high twist, and products with long floating points are better than products with short floating points.
5
Chemical wash (CHEMICAL WASH)
Chemical washing mainly achieves the purpose of fading by using strong alkali additives (NaOH, NaSiO3, etc.). After washing, the clothes will have a more obvious sense of staleness. Adding softeners will make the clothes soft and plump. If stones are added to chemical washing, it is called fossil washing (CHEMICAL STONE WASH), which can enhance the fading and wear effects, making the clothes have a strong sense of distress. Fossil washing combines the effects of chemical washing and stone washing. After washing, it can achieve an imitation and fluffing effect.
6
Rinse (BLEACH WASH)
In order to make the clothes have a white or bright appearance and a soft feel, the clothes need to be rinsed, that is, after ordinary washing in clean water, they are heated to 60°C and bleached according to the color of the clothes. For different shades, add an appropriate amount of bleaching agent and make the color consistent with the board within 7-10 minutes. During operation, the direction of adding bleach should be consistent with the direction of the rotating cylinder to prevent the bleach from falling directly on the clothes because it cannot be diluted with water quickly, causing partial bleaching.
Before bleaching, the water level in the tank should be slightly higher to facilitate dilution of the bleaching water. After the clothes are bleached, use large (baking) soda (Na2CO3, NaHCO3) to neutralize the residual bleach in the water to completely stop bleaching. After it has been washed with clean water, add detergent, fluorescent whitening agent, hydrogen peroxide, etc. to the water temperature of 50°C for post-washing to neutralize the PH value, fluorescent whitening, etc., and then soften it.
Rinsing can be divided into oxygen bleaching and chlorine bleaching. Oxygen bleaching uses the oxidation of hydrogen peroxide at a certain pH value and temperature to destroy the dye structure, thereby achieving the purpose of fading and whitening. Generally, the bleached cloth surface will be slightly red. Chlorine bleaching uses the oxidation of sodium hypochlorite to destroy the dye structure, thereby achieving the purpose of fading. Chlorine bleaching has a rough fading effect and is mostly used for rinsing indigo denim. After bleaching the boards, sea waves should be used to neutralize the residual chlorine in the water and clothing to stop the bleaching. After bleaching, stone grinding is performed, which is called BLEACH STONE WASH.
7
DESTROY WASH
After the ready-made garments are polished with pumice and treated with additives, certain parts (bones, collar corners, etc.) will be damaged to a certain extent, and the clothing will have a more obvious dilapidated effect after washing.
8
SNOW WASH
Soak the dry pumice with potassium permanganate solution, and then polish it directly with the clothes in a special rotating cylinder. Polish the pumice on the clothes so that the potassium permanganate oxidizes the friction points and makes the cloth surface uneven. Fades regularly, forming white spots that resemble snowflakes.
The general process of snowflake washing is as follows: pumice soaked in potassium permanganate – pumiceDry polish the clothes – match the snowflake effect – take out the clothes and wash them with clean water in the washing tank to remove the stone dust on the clothes – neutralize the oxalic acid – wash with water – apply softener.
9
Cat’s whiskers (MOUSTACHE EFFECT)
Cat’s whiskers are WHISKER, but WHISKER is more professional. Cat whiskers are a type of hand sand (HAND BRUSH), which is just ground into the shape of cat whiskers.
Cat whiskers are a common and complex process in the craft, which can be divided into ordinary cat whiskers, three-dimensional cat whiskers, hand-sewn cat whiskers, and horse whiskers. , hand-grabbed cat whiskers, resin cat whiskers, etc., the first ones are conventional cat whiskers, and the latter resin cat whiskers are true three-dimensional cat whiskers.
Steps of process production:
1: The semi-finished denim enters the process department for hand rubbing. Grinding, ordinary cat whiskers and other processes;
2: The washing department will check whether there are any deviations in the process, and if qualified, perform background color rinsing and drying;
3: Wash the denim with the background color and send it to the liquid medicine department, where the resin proportioning master will conduct a sample test. After the formula is determined, the liquid denim will be soaked and dried;
４: The resin-impregnated denim that has been dried to 80% is sent to the creasing department for a creasing test by the creasing master. If there are any problems, they can be immediately returned to the washing department for clean water. In severe cases, a lighter ratio can be used. Clean the Tianna water and then reconstitute the potion. Until the potion is not enough to damage the fabric;
5: The wrinkled pants should be put into a high-temperature furnace. The furnace should be supervised by a dedicated person, which will take about twenty minutes. If necessary, you can wipe it by hand and spray it with maliu;
６: Pass the water, and the washing master will perform corresponding color matching and cleaning, and then all the processes will be completed. !
10
SPRAY STONE WASH
Also called SAND BLAST, it uses special equipment (a kind of large electric toothbrush, just a roller type) to polish the cloth, usually with an inflatable model.
22
MONKEY WASH
The essential difference between sandblasting and sandblasting is that the former is a chemical effect, while the latter is a physical effect. Sandblasting is to use a spray gun to spray potassium permanganate solution onto the clothing according to the design requirements, and a chemical reaction will occur to cause the fabric to fade. The concentration of potassium permanganate used And the amount of spray is used to control the degree of fading. In terms of effect, spray maliu fades evenly, both the surface and the inner layer, and can achieve a strong fading effect, while sandblasting only fades on the surface, and the fibers can be seen.
12
Pigment wash / pigment dyed wash
Also called “single-sided coating / “Paint dyeing” means that this washing method is specially designed for clothing that has been dyed with paint. Its function is to consolidate the original bright color and increase the softness of the hand.
denim washing operation requirements
The washing and finishing process of denim clothing has evolved from traditional rinsing and stone grinding to enzyme washing, stone grinding, etc. The more popular ones today include cellulase stone grinding finishing, bio-polishing finishing of denim clothing, and non-ironing of pure cotton clothing. Finishing, etc. The process formulas and operation requirements of each process are described below.
1
Desizing
The purpose of desizing is to remove the sizing on the clothing to facilitate post-processing and have good production conditions. Since most denim uses starch or modified starch sizing, amylase can be used for desizing. Commonly used desizing processes Formula (per liter): 1~2g of BF-7658 amylase, 2~5g of salt, 1~2g of penetrant, 0.5~1.5mL of glacial acetic acid, 0~2g of softener. Process conditions: pH value. 6～7, liquor ratio 1:10-15, temperature 50～60℃, time 30min due to denim.There is usually residual alkali in the desizing bath, and acetic acid is added to the desizing bath to adjust the pH value to 6 to 7, so that the BF-7658 amylase can perform optimally. Softeners are added to prevent streaks in some heavy denim fabrics during the desizing process.
2
Cellulase stone grinding finishing
Cellulase is fermented by a single mold species. It can hydrolyze the surface of cellulose and partially generate short-chain polysaccharides and water-soluble products such as glucose. Since denim dyeing and finishing only dyes the fiber surface, cellulase partially hydrolyzes the cellulose surface and removes the dye attached to the fiber surface. According to the pH value requirements of the water bath during the stone mill water washing process, cellulase is divided into acid cellulase and neutral cellulase. The best pH value of acid cellulase is 4.5 to 5.5 (more sensitive to pH value and sold at a lower price). The optimal pH value of neutral cellulase is 6 to 8 (more stable to pH value and priced at a higher price).
Process conditions: cellulase 1.0% to 1.5% (weight of clothing), pH value 4.5 to 5.5 (acid enzyme), 6 to 8 (neutral enzyme), treatment time 45~120min, temperature 50~60C, the pumice dosage is 0~0.5kg/kg of clothing (depending on the degree of wear and tear), the bath ratio is 1:10~15. Using cellulase for stone-washing can greatly reduce the amount of pumice used (only about 25% of the original amount of pumice is used), or even eliminate the need for pumice. At the same time, it can increase the washing capacity of the washing machine and reduce environmental pollution. Due to the reduction of pumice grinding on the clothes, the clothes feel noticeably softer, more natural and brighter in color after washing.
During the stone-washing process, the indigo dye that falls off in the water bath has obvious back-staining when the pH is below 6, causing the denim to fade. The fabric seams including welts and the inner pocket material turn blue, and the blue/white contrast style is reduced after finishing. When the pH in the water bath is above 7, the back-staining phenomenon will be significantly reduced. Therefore, neutral cellulase is suitable for high-grade clothing finishing. Acid cellulase can be used in low-grade and various stone grinding rinsing processes.
3
Biopolishing finishing
Polishing enzyme can be used for polishing. It is a protein that plays a special catalytic role on the 1,4-β-glucose bond of cellulose. Its enzyme molecule is more than a thousand times larger than water molecules, so Cannot penetrate into the fiber. Hydrolysis can only occur in cellulose fibersIt is carried out on the 1.4-p-glucose bond on or near the surface.
Biopolishing finishing prescription: biopolishing enzyme 0.5% ~ 2.0% (weight of clothing), temperature 45 ~ 55℃, time 30 ~ 60min, penetrant 0.5 g/L, pH value 4.5~5.5 (adjusted with 0.5mL 98% HAc and 0.5g sodium acetate per liter), liquor ratio 1:10~15. On clothes treated with biopolishing enzymes, surface fluff is almost invisible and less prone to pilling. The hygroscopicity, drape, and feel of the clothes are significantly improved. Use the method of controlling the weight loss of clothing to 3% to 5% to judge the smooth effect without excessive damage to the strength. However, after biopolishing, some colors may change significantly, so please pay attention during use.
4
No-iron finishing of pure cotton clothing
Before the no-iron finishing of pure cotton clothing, the clothing must be thoroughly desized, washed, neutralized, and washed again to remove residual alkali on the clothing, because alkali can cause the catalyst to lose its effect. .
Non-iron resin finishing process formula: LF–2 resin (product of American Rising Sun Company) 100~130g/L, 531 (magnesium chloride catalyst) 25g/L , Bis-amino silicone emulsion AV–910 40-60g/L, non-ionic penetrant 2~4g/L, liquor ratio 1:5~10, room temperature 10-20min.
Process flow: clothes are dehydrated after soaking (liquid carrying rate 70%-80%) → dried (dried below 65°C until the moisture content is 5%-10 %) → ironing and shaping → rack baking (150-160℃, 5-15min). Clothes after non-iron finishing can meet customer needs in terms of feel, elasticity, wrinkle resistance and residual formaldehyde content (below 100mg/kg).
denim washing finishing – resin washing
The meaning of resin: resin usually It refers to an organic polymer that has a softening or melting range after being heated, and has a tendency to flow under the action of external force when softened. It is a solid, semi-solid, or sometimes liquid organic polymer at room temperature. Broadly speaking, any polymer that can be used as a raw material for processing plastic products is called resin.
Resin can be divided into natural resin and synthetic resin. Natural resin is made ofAmorphous organic substances derived from animal and plant secretions in nature, such as rosin, amber, shellac, etc. Synthetic resin refers to a resin product obtained by chemical synthesis of simple organic matter or chemical reaction of certain natural products.
Classification of resins: There are many ways to classify resins. In addition to dividing them into natural resins and synthetic resins according to their source, they can also be divided into synthetic reactions and main resins. Chain composition to classify.
1. Classification according to resin synthesis reaction
According to this method, resin can be divided into additive polymers and condensation polymers. Addition polymers refer to polymers produced by addition polymerization. The chemical formula of their chain link structure is the same as the molecular formula of the monomer, such as polyethylene, polystyrene, polytetrafluoroethylene, etc.
Condensation polymer refers to a polymer produced by condensation polymerization. The chemical formula of its structural unit is different from the molecular formula of the monomer, such as phenolic resin and polyester resin. , polyamide resin, etc.
2. Classification according to the main chain composition of the resin molecule
According to this method, the resin can be divided into They are carbon chain polymers, heterochain polymers and elemental organic polymers. Carbon chain polymers refer to polymers whose main chain is composed entirely of carbon atoms, such as polyethylene, polystyrene, etc.
Heterochain polymer refers to a polymer whose main chain is composed of atoms of two or more elements such as carbon and oxygen, nitrogen, and sulfur, such as polyoxymethylene, Polyamide, polysulfone, polyether, etc.
Plastic organic polymers refer to polymers that do not necessarily contain carbon atoms in the main chain, but are mainly composed of silicon, oxygen, aluminum, titanium, boron, sulfur, phosphorus and other elements. Made of atoms, such as silicone.
The resin used for denim is a finishing process. Resin finishing is the finishing of non-crystalline, amorphous organic compounds that are easily soluble in alcohol and ether. It acts as an anti-wrinkle, color-fixing and shaping agent.
The composition of resin: referred to as resin powder + water (resin water), which is prepared in a certain proportion and plays a role in shaping.
Advantages: Improved anti-wrinkle ability, crisp, easy to wash and quick-dry, no need for ironing, change and reduce the pilling phenomenon of chemical fiber fabrics, improve elasticity and shape retention ;
Disadvantages: The fabric’s breaking strength is reduced and its abrasion resistance is poor. Some resin treatments give the fabric a fishy odor. If not handled properly, the fabric will become yellowed and damaged.
The process of resin process: Soak clothes in liquid solution for about 15 minutes → Dehydration (liquid carrying rate 70%-80%) → Drying (drying below 65°C to moisture content 5%-10%) → Ironing and shaping →Rack baking (150-160℃, 5-15min). Clothes treated with no-iron treatment can meet customer needs in terms of feel, elasticity, wrinkle resistance and residual formaldehyde content (below 100mg/kg).
Notes (PS):
1. The resin in two parts (simple resin) can be sprayed with a spray gun (such as As shown in the picture); and multiple resins must be soaked in water
2. When drying, the drying time of thick fabrics and thin fabrics must be controlled ( Thick fabrics: 45 minutes Thin fabrics: 30 minutes)
3. When drying clothes, do not put clothes of different fabrics together and separate the fabrics (denim, linen, elastic)
4. When drying, use hot air for about 30 minutes, then cold air for 5 minutes
Extended reading: https://www. alltextile.cn/product/product-64-655.html
Extended reading:https://www.tpu-ptfe.com/post/7.html
Extended reading:https://www.tpu-ptfe.com/post/7734.html
Extended reading:https://www.china-fire-retardant.com/post/9659.html
Extended reading: https://www.alltextile.cn/product/product-37-335.html
Extended reading: https://www.alltextile.cn/product/product-13-878.html
