The definition of a fabric print
The process of making color pastes or pigments into pastes and applying them to fabrics for printing is called fabric printing.
Two common printing methods
• Flat screen printing
The patterned silk screen is tightly laid on the frame, and the paste is printed on the textile to form a pattern through the function of a printing blade.
The advantage of flat screen printing is that the size and color of the unit pattern are limited, and the flowers are rich in color. It is suitable for easily deformable fabrics. The disadvantage is that the straight pattern is easy to print, and the output of the shift is low.
• Rotary screen printing
Rotary screen printing machine is based on the automatic flat screen printing machine, the flat screen into a cylindrical metal nickel mesh, color paste pumped into the round net, under the role of the blade through the pattern at the mesh Printed on the fabric, the output is high, the printed pattern without joints printed, the printed color rich.
(3) Copper roller printing
It is a gravure printing. When printing, the color paste is embedded in the concave pattern of the printing plate, and the color paste is transferred to the fabric under the pressing to complete the printing. The pattern is clear and the yield is high, but the number of printed colors and the width of the fabric are limited.
Three printing post-processing equipment
• Steamer
After the printing process, the dye on the fabric is fixed on the fiber at a certain humidity and temperature, and the equipment is completed in this process.
(b) Drying equipment.
Some printing products do not need to be steamed, and are fixed by heat, such as paint printing, commonly used roller type baking machine.
(III) Washing equipment
Removes fabric sizing and unfixed dye wash soaping equipment
Printing paste
Printing paste is a macromolecular compound that thickens in printing paste. It is usually first dissolved in water to make a thick colloidal solution (printing paste), and then added to the printing paste.
• The role of the original printing paste in the printing process
(1) As a printing paste thickener, to ensure the contour of the pattern finish.
(2) Disperse the dyes, chemicals, and auxiliaries in the original paste uniformly at the required concentration.
(3) As a transfer agent for the diffusion of dyes from the fabric surface to the interior, it acts as a carrier.
(4) It is used as an adhesive to prevent the printing paste from falling off the fabric during processing.
(5) As a moisture absorption agent during steaming
(6) Stabilizers and protective colloids as printing pastes
• Performance of commonly used printing pastes
(1) Starch
Commonly used in printing is wheat starch and corn starch. The color paste produced has a high color amount and the printed pattern is clear. However, it has poor printability and uniformity, is not easily washed after printing, and is often mixed with other pastes to improve printing. System performance.
(2) etherified plant paste
Commonly used hull and soybean meal milled by the etherification reaction. Commonly used, such as synthetic dragon rubber, printing performance, good pattern leveling, high rate of paste, easy washing, good acid resistance, hold water Good, often used for chemical fiber printing and paint printing, and can be used with other pastes.
(3) Etherified cellulose derivatives
By the textile mill cellulose fiber left scrap. Commonly used carboxymethyl cellulose (CMC), the original paste was negative charge, can be used for reactive dye printing.
(4) Dextrin
It is an intermediate product degraded from starch. After the paste has high solid content and high water-holding property, it can be used for chemical fiber fabrics, especially cationic dye printing, to obtain fine and clear patterns; Yellow dextrin and dyeing and printing glue penetrate Excellent in dyeing, leveling and plasticity, high in solid content, excellent in dye-resistance, commonly used in vat dye printing.
(5) Natural rubber
It is produced from the liquid juice secreted by plants. Long rubber and gum arabic are commonly used. Long glue has high paste ratio, good water holding property, high color amount, easy washing performance, and is used for printing of soluble vat dyes and too cyanine dyes. , Often used in combination with starch paste. Gum arabic is generally made of 50% concentration of the original paste, its high solid content, good water holdup, adhesion, easy washing, acid and alkali resistant, suitable for wool, silk, chemical fiber fabrics printing.
(6) Seaweeds
The most commonly used is sodium alginate, which is derived from Sargassum and kelp. The original paste has good chemical stability and compatibility, good printing performance, good levelness, and good washability. It is ideal for reactive dye printing. Paste, suitable for printing chemical fiber fabrics and tight fabrics.
(7) Synthetic paste
Paint printing is not suitable for the application of natural thickeners. Commonly used emulsification paste thickening and synthetic thickener thickening. Emulsive paste for paint printing, bright color, smooth pattern, but causing volatile oil vapor pollution. Synthetic thickening The agent has a very low solid content and a good thickening effect. It is an ideal paste for flat screen and rotary screen printing. It has clear print lines and can be used for chemical fiber fabric printing.
Paint printing is the use of polymer compounds (binder) to paint (coloring agent) printed on the fabric, the high temperature treatment, the formation of a certain degree of elasticity and wear resistance of the transparent film, the coating fixed on the fiber printing method.
• The advantages of paint printing
(1) It is simple to use, simple in process, no need to wash after printing, and reduces waste water discharge.
(2) It can be applied to various fibers and various fabrics. In particular, blended fabrics are used with uniform coloring and no flash coloration occurs.
(3) Wide color spectrum, easy color matching, clear outline, strong three-dimensional appearance.
• Composition of paint printing paste
(1) Coating
Paint is a colorant for paint printing. It is in paste form. It is made by adding inorganic pigments or organic pigments after adding emulsifiers, wetting agents, etc. It is required to have good coloring power and hiding power, excellent chemical stability, and particles. Be fine and even.
(2) Adhesives
Most adhesives are polymer compounds made by copolymerizing two or more monomers. After post-treatment, they can form a wear-resistant, colorless, transparent, strong adhesive film on the fabric. Requires excellent chemistry Stability, filming feel soft, smooth and elastic.
• Non-crosslinking adhesives
Refers to the absence of reactive groups in the structure of the polymer, the need to add cross-linking agents. To improve the film fastness to rubbing. Such as: adhesive BH, adhesive 104
• Crosslinking adhesives
The binder polymer molecule contains reactive groups that react with cross-linking agents and fibers to increase the fastness. For example: Acramming FWR
• Self-crosslinking adhesives
The adhesive molecule contains a group capable of forming a cross-linking reaction by itself and undergoes a cross-linking reaction by itself to form a firm film. For example: Dongfeng self-crosslinking adhesive RFN
(3) Crosslinking agent
Also known as fixing agent or bridging agent, its purpose is to improve the wet processing and rubbing fastness of paint printing, reduce the baking temperature of the adhesive and shorten the baking time.
• Thermosetting resin
Commonly used trimethylol melamine (TMM) dimethylol dihydroxy cycloethylene urine (DMDHEU)
• Lively multifunctional compound
Such as: AccraFix FH Crosslinker 101
(4) Thickener
Emulsifying paste and synthetic thickener are pastes for paint printing and color mixing. Emulsified paste is a white paste obtained by emulsifying white oil and water with high speed and has good printing performance. After printing, it is baked. Dry emulsification paste is volatile; Synthetic thickener is a polymer compound, it has a convenient slurry, low solid content, clear printing profile, no need to wash after printing, etc., can replace the emulsification paste.
(5) Catalyst
The pigment is added to the paint printing paste to accelerate the cross-linking reaction rate of the adhesive and reduce the baking temperature after printing. The common catalysts are ammonium sulfate and magnesium chloride.
(6) Hygroscopic agent
Can maintain the color paste surface wetting, no skinning, improve the color paste stability at high temperatures, commonly used urea.
(7) Softener
Can make the fabric surface smooth, soft to the touch, improve the friction fastness. Common silicone softener.
Duvet Set,Duvet Cover Set,Duvet Cover Sets,White Duvet Cover
Changxing Xingang Textile Co.,Ltd , https://www.xingangtextile.com