Printing and dyeing process

In the printing and dyeing industry, according to different raw materials, different yarn types, different fabric structure, different printing and dyeing requirements, the process flow is not a completely fixed mode, such as chemical fiber textile printing and dyeing, wool textile printing and dyeing, silk industry silk Weaving and dyeing, the difference is quite large, and even they can hardly learn from each other. Then, we first understand the routine processes in the three industries of spinning, weaving, printing and dyeing, etc., to have a simple understanding of the spinning and dyeing industry, and also have an overall impression of the source of bedding fabrics.
Main processes of the spinning process: cleaning, carding, combing, drawing, roving, spinning
Main processes of weaving process: winding, warping, sizing, piercing, weaving, finishing
These are the main processes, and each company will have a slightly different process depending on the product and its needs. Let's take the cotton as an example to share the conventional cotton textile printing and dyeing process.
Cotton textile printing and dyeing process:
Blender - seam head - singeing - cold rolling car - retreating and bleaching - mercerizing - pre-fixed tenter - pulping - printing (flat or rotary screen printing) - steaming machine - -Soap washing machine--Finishing and setting--Pre-shrinking machine--calender--inspection packaging

Singeing

Usually, after the grey cloth enters the printing and dyeing factory, it first needs to be inspected, turned, batched, and the blank (the blank: the front and back sides of the two grey fabrics, the same surface) and the seaming process, and then the singeing process.
Singeing: The process of singeing looks very magical. At the scene, you will see that the fabric is flat and fast through the high temperature flame, and the cloth slides quickly on the blazing flame, but it does not burn. It is a bit "there is no leaf in the flowers." The realm of "stained".
This is because the cloth body is relatively tight and the temperature rises slowly. When it is not raised to the fire point, it has left the flame or the red hot metal surface, so as to achieve the purpose of burning the fluff without damaging the fabric.
Reason: The unsmoldered cloth has too many fluffs, different lengths, poor finish and easy staining. It is easy to fall in the subsequent dyeing and finishing process, resulting in printing and dyeing.
Significance:
1. The purpose of singeing is to burn the fluff on the cloth surface to make the cloth surface smooth and beautiful, and to prevent uneven dyeing and printing plague due to the presence of fluff during dyeing and printing. Improve the gloss of the fabric and improve the finish;
2. Improve anti-pilling performance (especially chemical fiber fabric);
3, improve the style, singeing will make the fabric become crisp.

Cold rolling car: a process after singeing, the fabric needs to be cooled for more than 20 hours

Boiled and rinsed

De-cooking, that is, desizing, scouring, bleaching.
Desizing: The slurry on the grey fabric should be removed before scouring. This process is called desizing.
In order to increase the abrasion resistance, smoothness and antistatic property of the warp yarn in weaving, the strength is improved, the woven property is improved, and sizing processing is performed before weaving. The slurry on the grey cloth affects the water absorption performance of the fabric, and also affects the quality of the dyeing and finishing product, and increases the consumption of dyed chemicals. Therefore, the slurry should be removed before scouring. This process is called desizing. It is about to be removed from the fabric.
Scouring: Refining, also known as scouring, is designed to remove fiber impurities (natural impurities, artificial impurities) and improve fabric processing properties, especially wetting properties.
When cotton fibers are grown, natural impurities (pectin, waxy substances, nitrogenous substances, etc.) are accompanied. After the cotton fabric is desizing, most of the slurry and some natural impurities have been removed, but a small amount of slurry and most of the natural impurities remain on the fabric. The presence of these impurities makes the fabric of the cotton woven fabric yellower and has poor permeability. At the same time, due to the presence of cottonseed hulls, the appearance quality of cotton fabric is greatly affected.
Therefore, it is necessary to scouring the fabric in a concentrated alkali solution at a high temperature for a long time to remove residual impurities.
Bleaching: After being scoured, cotton fabrics are not white enough due to the presence of natural pigments on the fibers. They are used for dyeing or printing, which will affect the vividness of the color.
The purpose of bleaching: removing the pigment and improving the whiteness for the main purpose of bleaching.

Mercerizing

Mercerizing: The cotton woven fabric is treated with a concentrated alkali solution, the surface of which is silky luster, and more importantly, the dimensional stability is improved, that is, the cotton woven fabric is shaped.
This process is called Mercerization or Mercerizing, and Chinese is translated as Messer or simply as Mercer.
The meaning of mercerizing:
1. The dimensional stability is improved and the shrinkage rate is reduced;
2. Mechanical mechanical properties such as breaking strength are reduced;
3. Adsorption improvement;
4, the appearance of silky luster.

The tenter

Stretching is to elastically process the warp and weft of the fabric again, so that the warp and weft width of the fabric is uniform, the density is uniform, and the dimensional stability of the fabric is increased.

Pulping and stereotypes

The jacquard varieties are sizing to varying degrees before calendering, so that the slurry is attached to the surface of the fiber to prevent the cloth door from retracting. The sizing has a softening effect and promotes the friction between the fibers and the fibers.

Printing

At present, there are two widely used printing methods, round net and flat net printing. Due to the small tension, it is not easy to be deformed, the color of the flower is bright, the color is full, and the screen printing is less, which is especially suitable for multi-variety production. The rotary screen and the flat screen printing require a screen from the device. It originates from the type printing, and is a printing method for printing a paper plate, a metal plate or a chemically carved hollow pattern.
The round mesh uses a nickel round metal mesh, while the flat mesh stretches the mesh onto a metal or wooden rectangular frame. Flat screen printing is divided into manual (platen printing) and mechanical (flat screen printing). Due to the different printing methods, the size is relatively limited, and the flat mesh size is 305~1200mm. Generally, the circumference of the net-printed net has a circumference of 640 mm 820 mm 1018 mm. The circumference is a multiple of the pattern of the pattern.
The characteristics of the rotary screen are the pattern connection, and there is no printing.
The net of the flat screen printing is square, so that his cycle is not restricted, and the flat net has a position.
In general, rotary screen printing output is the most, generally 3,500 yards per hour, depending on the difficulty of the pattern to determine the speed of the speed. The flat screen printing fineness and flower return size are superior to the rotary screen, but the production efficiency is not as fast as the rotary screen. In the actual choice, it is necessary to choose the round net or the flat net according to the use of the fabric, the size of the flower, the fabric and the like.

Steamed, soaped

Steaming: After printing textiles, in addition to ice dyes and soluble vat dyes, the dyes are generally steamed.
OBJECTIVE: To make the printed textiles absorb moisture and heat up the fiber and color paste film, accelerate the reduction of the dye and dissolve on the fiber, and diffuse the dye into the fiber and fix it on the fiber to diffuse into the fiber to produce solid color. The process conditions for steaming vary with the nature of the dye and fiber.
Soaping: It is a very necessary and important process after steaming. In the soaping process, the soaping agent can improve the soaping fastness and anti-staining by the physical and chemical action between the dyeing agent and the dispersing, suspending and complexing of the soaping agent, so that it is no longer applied to the fabric. the goal of.

Pre-shrinking

During the printing and dyeing process, there is internal stress in the tensile process of mechanical tension. When the fabric is wet, the internal stress is relaxed, which will cause shrinkage effect. Therefore, in the actual production, the fabric must be mechanically pre-shrinked to reduce the cotton fabric. The shrinkage rate makes the finished product stable in size, keeps the fabric width neat, and increases the added value of the product.

Calendering

Also known as calendering. A process of finishing fabrics. The finishing process of the fabric gloss is increased by the physical plasticity of the fiber under high pressure or high temperature conditions to flatten or roll the surface of the fabric. Similar to ironing, the surface is flattened and ironed to give the fabric a special luster, which enhances the brightness of the fabric and makes the fabric feel good and flat.

Product inspection packaging

At this point, the printing and dyeing of the cloth is completed. Quality inspection and scrolling. If the pattern is leaky, it needs manual decoration and packaging.

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Edit by Invelychem