Gray fabric printing and dyeing process

1. Inspection and seaming of gray fabrics:

A. The gray fabrics are sewn one by one into a large roll or box, called a cylinder. The number of a cylinder varies depending on the type of fabric processed.

B. Gray fabric inspection is mainly to control the quality of gray fabrics to see if there are any abnormalities such as drawing, weft stops, dead folds, yellow spots, mildew spots, etc. At the same time, attention should be paid to checking whether the fabric type is consistent with the requirements. Under normal circumstances, a batch number is required for inspection.

　2. Desizing:

A. In order to make the yarn lint-free during weaving, the yarn is sizing, so it needs to be desized before dyeing to facilitate coloring.

B. If the desizing is not clean, defects such as color flowers and pulp spots will appear on the cloth after dyeing.

C. After desizing, it generally needs to be washed with water, otherwise the PH value of the fabric will be high and abnormalities such as poor dyeing may occur.

D. There are generally two desizing methods: in-cylinder desizing and long car desizing. Generally, the former has better desizing effect, but has low efficiency.

3. Dyeing:

(1) Chemical fiber dyeing method:

A. Normal temperature jig dyeing: 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 jig dyeing: The temperature is generally around 130°C. It is mainly used to dye polyester taffeta, N66, nylon matt cloth, polyester Oxford (filament), etc. This method is prone to color difference between the head and tail, left, center and right. Abnormalities such as color difference, creases, and color spots.

C. Overflow dyeing: The temperature is about 100℃ to 130℃. It is mainly used to dye polyester such as pongee, peach skin, polyester Oxford, Taslon, nylon-polyester interweaving, etc. Polyester spinning is also Overflow dyeing can be used, and this method is also used for nylon and other products that require dyeing and wrinkles. This method is easy to produce abnormalities such as color flowers, chicken claw marks, and straight strips of dyeing and folding. D. Beam dyeing: suitable for all kinds of fabrics, but it must be used reasonably according to quality requirements. The dyeing temperature can be controlled above 100°C to 130°C. This method is prone to abnormalities such as shallow edges and layer differences.

(2) Dyeing methods of other fabric types:

A. Cotton dyeing: Generally, long machine dyeing is used (Large batches are required), pad dyeing (can be large or small batches), overflow dyeing (medium and small batches). Reactive dyes (good fastness), direct dyes (poor fastness), and vat dyes (good fastness) can be used.

B, N/C, C/N dyeing: Generally, overflow dyeing is used, cotton is dyed first and then nylon is dyed. Reactive dyes are used to dye cotton, and acid dyes (with better fastness) are used to dye nylon. Direct dyes are also used for one-time dyeing (poor fastness).

C, T/C, C/T dyeing: Generally, overflow dyeing is used. Polyester is dyed first and then cotton. Disperse dyes are used for polyester and reactive dyes are used for cotton (with better fastness). There are also long lathe dyeing methods, which are dyed in one go, and direct dyes (poor fastness) are used.

(3) Dye classification:

A. Acid dyes: used for dyeing nylon fabrics. Generally, the color must be fixed to improve the color fastness. Attention must also be paid to the selection of dye combinations and the adoption of reasonable dyeing processes. Improper selection of fixative or too high a dosage will result in a hard feel.

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 use of reasonable dyeing processes. Disperse dyes pay special attention to dye migration problems and sublimation fastness problems.

C. Reactive dyes and direct dyes: belong to low-temperature dyes.

4. Drying:

(Generally divided into two types: drum drying and non-contact drying) A. Non-contact drying includes non-contact dryers and setting machines. There is no contact between the fabric and the heater, and the hot air is sprayed onto the fabric. Come up to achieve the purpose of drying. Mainly used for drying overflow dyed products to maintain the fluffy and rich feel of the fabric. The cost is higher than that of drum drying. B. Drum drying: The cloth and the drum are in direct contact, and the drum is heated to achieve the purpose of drying the cloth. Mainly used for jig dyeing and beam dyeing products (such as nylon yarn, polyester yarn, nylon Oxford, polyester filament Oxford, etc.), Taslan can also be dried in a drum dryer first (but only first Bake it to 60% to 70% dryness to avoid it feeling too hard), and then go to the setting machine for water-splashing processing to increase the degree of water-splashing. Drying costs are lower.

5. Central inspection:

A. The intermediate inspection should test various color fastnesses of fabrics, and also pay attention to check the quality of the cloth surface, such as: creases, color difference (color difference, cylinder difference, patch difference), color flowers, color spots, dirt, Oil stains, drawn yarn, weft bars, warp strips, etc. B. Control defective products from entering the lower work section to prevent an increase inThe cost is increased because after the fabric is finished and processed, some abnormalities cannot be repaired or repair is very difficult, so mid-inspection is very important. C. The fabrics must be rearranged and sewn before entering the final section.

6. Finalization:

A. After the fabric is shaped, its physical and chemical properties are relatively stable. For example, 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 shaping section, such as water repellent (waterproof), softness, resin coating, flame retardant, antistatic, super water repellent (Teflon treatment), moisture wicking, antibacterial and deodorant, etc. . B. Because the setting temperature is high, you should pay attention to the color changes before and after setting, especially some sensitive colors, such as gray, military green, light khaki, etc. Products generally require the color to be aligned after finalization. C. Styling can control the width, warp and weft density, shrinkage, etc. of the cloth. Especially the control of shrinkage directly affects the processing cost, so special attention should be paid to it. (Our company’s order shrinkage requirement is generally 3% washing shrinkage, and strict requirements are 2% washing shrinkage). The three main factors that affect the setting effect are setting temperature, speed and overfeeding. D. Introduction to several types of shaping processing:

① Water splashing makes the fabric waterproof and dustproof;

②Soft styling makes the fabric feel soft and smooth, but pay attention to whether the fabric will slip. Water repellency and soft styling can be done at the same time to make the fabric both waterproof and soft, but the softener will affect the degree of water repellency.

③ Resin shaping is mainly used to fix the yarn of the fabric and make the hand feel stiff. Some resins contain formaldehyde, so be careful when selecting them; water splashing and resin shaping can be done at the same time, and the resin can promote the water splashing agent.

④ Flame retardant styling has an auxiliary effect on the flame retardant function of the fabric. Flame retardant can also be water-repellent styling at the same time, but special attention should be paid to the selection of water-repellent agent, otherwise the flame retardant effect will be too great.

⑤ Antistatic styling makes the fabric antistatic and can be done at the same time as water-splashing styling, but it will have an impact on the water-splashing effect.

⑥ Moisture-wicking and perspiration shaping allows the fabric to quickly absorb sweat, making sportswear more comfortable to wear. It cannot be done at the same time as splashing water.

　⑦ Antibacterial and deodorizing processing mainly makes fabrics have antibacterial functions and is mainly used in medical facilities.

⑧Super water-repellent styling (also called Teflon treatment): It has better waterproof and dust-proof effects than ordinary water-repellent styling, and it also has oil-proof function. Generally speaking, customers will ask for a DuPont hangtag.

7. Calendering and gluing:

A. The functions of calendering ① Soften the feel ② Make the calendered surface of the fabric smoother, narrow the gaps between the fabric fibers to prevent velvet effect or achieve higher water pressure when applying glue ③ Make the glued surface smoother More smooth and 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, velvet-proof, windproof and other functions. It can also fix the fabric, increase the look and feel, and thicken the feel, making the fabric more valuable. 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, colored glue, pearlescent glue, excellent glue, etc. Corresponding raw materials can also be added to the glue to make it anti-ultraviolet, flame retardant, and anti-yellowing.

E. When applying glue, pay attention to controlling the water pressure, feel (thickness, softness and hardness), glue uniformity, glue peeling strength, water washing resistance (whitening), whiteness, etc. Also pay attention to the rubber particles, glue marks, and whether it is dry on the rubber surface. Pay attention to the effect of applying waterstop strips (PVC strips/PU strips) on the rubber surface.

8. Laminating PVC: Pay attention to the thickness and feel of the lamination, the peel strength of the lamination, the quality of the adhesive surface, etc.

9. Other processing: dry PU (release paper), composite, PU leather, etc.

10. Washing: Some cotton, N/C, and T/C also need to go through the washing process. There are three types of washing: ordinary washing, soft washing, and enzyme washing (to remove floating hair on the surface of cotton cloth).

22. Finished product inspection: Inspect the quality of finished products, classify them into grades, and package and organize them for shipment. Generally, inspection records and matching discrepancies must be posted. If you have any questions, please report them to the salesperson promptly so that you can communicate with customers in a timely manner.