Printing and dyeing is an important part of textile processing, involving the application of color, pattern or chemical treatment to the surface of the fabric to give it the desired appearance, function or texture. Printing and dyeing includes not only dyeing the fabric, but also printing, pulp dyeing, finishing and other technical means. Below I will explain in detail the basic printing and dyeing process of cloth and common printing and dyeing methods.
First, the basic printing and dyeing process of cloth
The basic printing and dyeing process of fabric can be divided into several key steps, covering the whole process from the preparation of fabric to the completion of printing and dyeing.
1. Pre-treatment (preparation)
Before the fabric is dyed or printed, a series of pretreatment steps must be carried out to ensure that the dye or printing is better and to make the fabric more suitable for dyeing.
Open: The fabric is spread out from the roll to allow for even handling.
Washing: Remove impurities, grease, wax and dust from the surface of the cloth to make it cleaner and avoid affecting the adsorption of dyes.
Degreasing: For fibers containing natural oils (such as cotton, wool, etc.), degreasing treatment is to remove plant or animal oils and ensure that the dye adheres better.
Bleaching: In order for a cloth to achieve a pure white color, it is sometimes necessary to remove its surface color with bleach, especially when natural fibers are treated before dyeing.
Finishing: This includes sizing, shaping, and removing residues in preparation for dyeing or printing.
2. Dyeing
Dyeing is the process by which dyes are introduced into the fabric fibers to give the fabric the desired color. The method of dyeing varies according to the type of fabric, the type of dye, and the production needs.
Common dyeing methods include:
Bath Dyeing: This method is to completely soak the cloth in a dye solution, the dye penetrates into the fabric fiber through diffusion and adsorption, the whole dyeing process can be divided into mild dye penetration stage and thermal curing stage. Immersion dyeing method is suitable for mass production, especially mass dyeing (such as fabric dyeing, towel dyeing, etc.).
Pad Dyeing: The fabric is passed through a series of dye baths, and the dye is applied to the surface of the fabric through a roller or printing table, and the dye is then heated and fixed to penetrate into the fiber. Roller dyeing is suitable for dyeing methods with specific requirements, such as uniform dyeing of large areas.
Spray Dyeing: This method is to spray dye to the surface of the fabric in a spray way, often used for dyeing processes with special texture or pattern requirements.
Jet Dyeing: Use a pressure jet system inside the dyeing machine to spray a dye solution evenly onto the fabric. This method is suitable for a variety of fibers and allows for precise dyeing results.
Pre-dyeing and post-dyeing: Pre-dyeing refers to dyeing the yarn before weaving; Post-dyeing means dyeing the fabric after weaving it. Post dyeing is usually suitable for color changes and batch dyeing.
3. Print
Printing is the process by which dyes or pigments are applied to the surface of cloth through specific techniques to form patterns. Printing is suitable for fabrics that need pattern decoration, such as clothing fabrics, home textile fabrics, etc.
Common printing methods are:
Screen Printing: Screen printing is the printing of pigment onto the surface of the fabric through screen printing technology (usually Screen Printing). According to different screens, you can make different colors, different patterns of printing effects. This method is suitable for mass production and can achieve high quality and high precision pattern printing.
Flexographic Printing: Printing using an elastic offset plate (usually a rubber material), the offset plate is coated with ink, and the pattern is transferred to the fabric by embossing technology. Offset printing is low in cost, suitable for mass production, and printing speed is fast.
Heat Transfer Printing: The printed pattern is transferred to the cloth by a hot press. The transfer method can achieve high detail pattern transfer and is suitable for a variety of fiber types.
Digital Printing: The use of digital printing technology, the pattern is directly printed on the surface of the cloth by inkjet. This method is flexible and suitable for small batch production, enabling fine pattern details.
Foam Printing: The use of foam printing ink for printing, printing patterns have a three-dimensional sense, often used in fashion or unique effects of fabric.
4. Styling and post-processing
Dyed and printed fabrics usually need to be shaped to ensure color fastness, gloss, and stability.
Setting: Setting treatment is to heat, stretch and compress the dyed or printed fabric to stabilize its shape, avoid shrinkage and deformation, and ensure the final dimensional stability.
Color fixing: The color fixing treatment is to make the dye firmly fixed on the fiber by chemical methods to avoid fading in daily washing or friction.
After finishing: including waterproof, anti-fouling, antibacterial, anti-UV and other functional treatment, as well as soft treatment, make the fabric more comfortable and durable.
Second, common printing and dyeing methods
Dyeing method
Water bath dyeing: The cloth is soaked in the dyeing solution for a long time, suitable for mass production.
Airflow dyeing: Suitable for efficient, fast dyeing, usually used for synthetic fibers.
Polymer dyeing: A special method of dyeing synthetic fibers, often used in polyester fibers.
Printing method
Reactive printing: The use of reactive dyes for printing, suitable for natural fibers, bright and strong color.
Disperse printing: The use of disperse dyes, suitable for synthetic fibers such as polyester.
Pigment printing: Pigments do not chemically react with fibers, but adhere to the surface, suitable for a variety of fibers, bright colors.
Functional printing and dyeing: Modern textile printing and dyeing is not limited to colors and patterns, many technologies also involve functional treatments, such as waterproof, fireproof, antibacterial, etc., to meet specific market needs.
Summary
The printing and dyeing process of a fabric consists of several steps, from pre-treatment to dyeing, printing, setting and post-treatment, each of which has an important impact on the final fabric. The choice of printing and dyeing method depends on the material of the fabric, the required effect, the production volume and the cost. With the development of technology, more and more innovative methods and environmentally friendly dyes are applied to the printing and dyeing industry to improve production efficiency, ensure environmental friendliness and meet the diverse needs of consumers.
