Gray cloth printing and dyeing process
Blank inspection and sewing gray fabric → desizing → dyeing → drying → intermediate inspection → shaping → calendering and gluing → laminating PVC → other processing → washing → finished inspection
1.Gray fabric inspection and seaming:
A. It is to sew gray cloths one by one into a large roll or a box of cars, which is called a cylinder, and the number of cylinders varies with different types of fabrics.
B. Gray fabric inspection is mainly to control the quality of gray fabric, to see if there are abnormalities such as drawn yarn, weft gap, dead fold, yellow spot, mildew spot, etc. At the same time, pay attention to check whether the fabric type is consistent with the requirements. Under normal circumstances, a batch number is required to pay attention to inspection.
2. Desizing:
A. In order to make the yarn lint-free during weaving, the yarn is sized, so it must be desized before dyeing for coloring.
B. If the desizing is not clean, there will be stains, pulp spots and other defects on the cloth surface after dyeing.
C. After desizing, it is generally necessary to wash it with water, otherwise the pH value of the fabric will be high and abnormalities such as poor dyeing will occur.
D. Desizing methods generally include in-cylinder desizing and long-car desizing. Generally, the former desizing effect is better, but the efficiency is low.
3. Dyeing:
(1) Chemical fiber dyeing method:
A. Jigger dyeing at room temperature: the general temperature is below 100 ℃, mainly used for dyeing semi-gloss nylon taffeta, nylon oxford, nylon twill, etc. This method is prone to abnormalities such as head-to-tail chromatic aberration, left-middle-right chromatic aberration, and creases.
B. High temperature jigger dyeing: the temperature is generally about 130°C, mainly used to dye polyester taffeta, N66, nylon matte cloth, polyester Oxford (filament), etc. This method is prone to color difference between head and tail, left, middle and right, and folding Abnormalities such as marks and color spots.
C. Overflow dyeing: The temperature is about 100°C to 130°C. It is mainly used to dye polyester such as pongee, jeanette, polyester Oxford, Taslan, nylon and polyester interwoven, etc. Polyester spinning can also be used for overflow Dyeing, and this method is also used for nylon spinning and other dyeing and wrinkle requirements. This method is prone to abnormalities such as colored flowers, chicken claw marks, straight dyeing and folding.
D. Warp beam dyeing: suitable for all kinds of fabrics, but it should be used reasonably according to the quality requirements. The dyeing temperature can be controlled at 100°C to above 130°C. This method is prone to abnormalities such as shallow edges and layer differences.
(2) Dyeing methods of other cloth types:
A. Cotton dyeing: Generally, long-car dyeing (requires large batches), pad dyeing (large batches or small batches), overflow dyeing (medium and small batches) are used. Available reactive dyes (better fastness), direct dyes (poor fastness), and vat dyes (best fastness)
B. N/C, C/N dyeing: Generally, overflow dyeing is used, cotton is dyed first and nylon is dyed, cotton is dyed with reactive dyes, and nylon is dyed with acid dyes (better fastness). There are also one-time dyeing with direct dyes (poor fastness).
C, T/C, C/T dyeing: Generally, overflow dyeing is adopted, polyester is dyed first and then cotton is dyed, disperse dyes are used for polyester, and reactive dyes are used for cotton (good fastness). There are also long-term dyeing methods, one-time dyeing, and direct dyeing (poor fastness).
(3) Classification of dyes:
A. Acid dyes: used to dye nylon fabrics. Generally, the color should be fixed to improve the color fastness. Attention should also be paid to the selection of dye combinations and the adoption of a reasonable dyeing process. Improper selection of color-fixing agent or too high dosage will result in hard hand feeling.
B. Disperse dyes: used for dyeing polyester fabrics. Generally, reduction washing is used to improve the color fastness. At the same time, attention should be paid to the selection of dye combinations and the adoption of reasonable dyeing processes. Disperse dyes pay special attention to the problem of migration and fastness to sublimation.
C. Reactive dyes and direct dyes: belong to low-temperature dyes.
4. Drying: (generally divided into two types: tumble drying and non-contact drying)
A. Non-contact drying There are two types of non-contact dryers and setting machines. There is no contact between the fabric and the heater, and the purpose of drying is achieved by spraying hot air onto the fabric. It is mainly used for drying overflow dyed products to keep the fluffy and rich hand feeling of the fabric. The cost is higher than tumble drying.
B. Drum drying: The cloth is in direct contact with the drum, and the cloth is dried by heating the drum. Mainly used for jigger dyeing and beam dyeing products (such as nylon spinning, polyester spinning, nylon Oxford, polyester filament Oxford, etc.), Taslan can also be dried on the drum dryer first (but only first Bake 60% or 70% dry to avoid too hard hand feeling), and then go to the setting machine for water-splashing processing to increase the water-splashing degree. Drying costs are lower.
5. Intermediate inspection:
A. The inspection shall test the various color fastness of the fabric, and at the same time pay attention to the quality of the cloth surface, such as: crease, color difference (color difference, cylinder difference, fit difference), color flower, color point, dirt, oil stain, drawn yarn , weft files, warp strips and so on.
B. Control defective products and prevent them from entering the next section to prevent cost increase. Because after finishing and processing, some abnormalities cannot be repaired or repaired is very difficult, so the intermediate inspection is very important.
C. Before the fabric enters the back section, it needs to be rearranged and stitched.
6. Shape/Setting:
A. After the fabric is shaped, its physical and chemical properties are relatively stable, such as: shrinkage, width, warp and weft density, etc. are not easy to change, and the cloth surface is relatively smooth. At the same time, some functional processing can also be done in the finalizing section, such as water repellency (waterproof), softness, resin coating, flame retardant, antistatic, super water repellency (Teflon treatment), moisture absorption and perspiration, antibacterial and deodorant, etc. .
B. Due to the high setting temperature, attention should be paid to the color change before and after setting, especially some sensitive colors, such as gray, army green, light khaki, etc. Products generally require alignment with the finalized color.
C. Shaping can control the cloth width, warp and weft density, shrinkage, etc., especially the control of shrinkage, which directly affects the processing cost, so special attention should be paid. (Our company's order shrinkage requirement is generally 3% washing shrinkage, and the strict requirement is 2% washing shrinkage). The main factors affecting the setting effect are the three major factors of setting temperature, speed and overfeeding.
D. Brief introduction of several types of processing:
① Water-splashing and shaping make the fabric waterproof and dustproof;
②Soft setting makes the fabric feel soft and smooth, but pay attention to whether the fabric will slip. Water repellency and soft setting can be done at the same time, so that the fabric is both waterproof and soft, but the softener will affect the degree of water repellency.
③Resin setting is mainly used for fabric fixing and making the hand feel stiff. Some resins contain formaldehyde, so pay attention to the selection; water splashing and resin setting can be done at the same time, and the resin can promote water repellent.
④Flame retardant setting has an auxiliary effect on the flame retardant function of the fabric. The flame retardant can also be water-splashing and setting at the same time, but special attention should be paid to the selection of water-repellent agent, otherwise the flame-retardant effect will be greatly affected.
⑤ Antistatic setting makes the fabric have antistatic function, which can be done at the same time as water-splashing setting, but it will affect the water-splashing effect.
⑥Moisture absorption and perspiration shaping allow the fabric to quickly absorb sweat, making it more comfortable to wear as sportswear. It cannot be done at the same time as splashing water.
⑦ Antibacterial and deodorant processing is mainly to make the fabric have antibacterial function, which is mainly used in medical facilities.
⑧Super water-splashing setting (also called Teflon treatment): it has better waterproof and dustproof effects than ordinary water-splashing setting, and it also has oil-proof function. Generally speaking, customers will ask for a DuPont tag.
7. Calendering and gluing:
A. The function of calendering ① soften the handle ② make the calendered surface of the fabric smoother, narrow the gaps between fabric fibers to prevent velvet effect or achieve higher water pressure when gluing ③ make the gluing surface smoother Beautiful ④The calendered surface has a bright effect.
B. The three elements of calendering are temperature, speed and pressure. Calendering changes the color of the fabric.
C. Gluing can make the fabric waterproof, fleece-proof, windproof and other functions, as well as fix the yarn of the fabric, increase the look and feel, thicken the handle, etc., so that the fabric has more use value.
D. Gluing includes acrylic (also known as AC, PA), PU glue, moisture-permeable and breathable glue, which can be processed into transparent glue, white glue, silver glue, color glue, pearlescent glue, Youli glue and so on. Corresponding raw materials can also be added to the glue to make it anti-ultraviolet, flame-retardant, and anti-yellowing.
E. Pay attention to the control of water pressure, hand feeling (thickness, softness and hardness), uniformity of glue application, peel strength of glue, washing resistance (whitening), whiteness, etc. when applying glue. Also pay attention to the rubber particles, glue marks, and whether it is dry on the rubber surface. Pay attention to the effect of the waterstop (PVC strip/PU strip) on the rubber surface.
8. Bonding PVC: Pay attention to the thickness, feel, peeling strength of bonding, and the quality of the rubber surface.
9. Other processing: dry PU (release paper), composite, PU leather and so on.
10. Washing: some cotton cloth, N/C, T/C have to go through washing process. Washing is divided into three types: ordinary washing, soft washing, and enzyme washing (removing the floating hair on the surface of the cotton cloth).
11. Finished inspection: Inspect the quality of finished products, classify them into grades, and pack them for shipment. Generally, inspection records and matching difference tables are required. If there is any problem, it should be fed back to the salesman in time so as to communicate with customers in time.