Principle And Process Of Thermal Sublimation Transfer Printing

Transfer printing refers to the printing process in which the dye is transferred to the fabric by transfer paper. According to the sublimation characteristics of some disperse dyes, the disperse dyes sublimated at 150-230 ° C are selected and mixed with the slurry to make "color ink", and then according to the requirements of different design patterns, the "color ink" is printed on the transfer paper (this is a special paper, so called transfer paper), and then the transfer paper with pattern patterns is closely contacted with the fabric Under pressure and time, dyestuff It is transferred from the printing paper to the fabric and diffused into the interior of the fabric to achieve the purpose of coloring.

Transfer printing is not only suitable for synthetic fabrics, but also for natural fiber pure and blended fabrics. It has the following advantages: (1) no water, no sewage; (2) The process flow is short, and after printing is the finished product, without post-treatment processes such as steaming and washing; (3) Fine patterns, rich and clear levels, high artistry, strong three-dimensional sense, which is better than common printing methods, and can print patterns of photographic and painting styles; (4) The printing color is bright. During the sublimation process, the tar in the dye is left on the transfer paper, which will not pollute the fabric; (5) High rate of authentic products, multiple color patterns can be printed at one time when transferring, without the need for double printing; (6) It is flexible and can be printed in a short time after customers select patterns.

The sublimation method is to use Disperse dye The ink is made of disperse dyes with molecular weight of 250-400 and particle diameter of 0.2-2 μ m, water soluble carrier (such as sodium alginate) or alcohol soluble carrier (such as ethyl cellulose) and oil soluble resin. The ink is processed on a transfer printing machine at 200-230 ° C for 20-30 seconds to transfer the disperse dyes to synthetic fibers such as polyester.

The sublimation process generally goes through three processes: before the transfer process occurs, all dyes are in the printing film on the paper and are Printed fabric And the concentration of dyes in the air gap is zero, and the size of the air gap depends on the fabric structure, yarn count and transfer pressure; In the transfer process, when the transfer temperature is reached, the dye begins to volatilize or sublimate, and forms concentration volatilization between paper and fiber. When the printed fabric reaches the transfer temperature, the dye adsorption starts on the fiber surface until a certain saturation value is reached. Since the transfer of dyes from paper to fiber is continuous, the adsorption rate depends on the rate of dye diffusion into the fiber. In order to make the dye diffuse directionally, vacuum is often pumped at the bottom side of the dye to make the dye diffuse directionally; After the transfer process, after the dye is dyed, the dye content on the paper decreases, and some of the remaining dyes migrate to the inside of the paper. The amount of the remaining dyes depends on the vapor pressure of the dyes, the affinity of the dyes to the pulp or transfer paper, and the thickness of the printing film. Sublimation method generally does not require wet treatment, which can save energy and reduce the load of sewage treatment.

Heat sublimation transfer printing process: heat transfer paper is produced through computer design - computer color separation - electroengraving - wheel intaglio printing - heat transfer processing to polyester chemical fiber fabric, TC cloth, plush fabric, artificial leather and other different materials through computer design - computer color separation - electroengraving - wheel intaglio printing - heat transfer processing. Compared with traditional silk screen printing and dyeing printing, this process printing has more abundant patterns, In terms of clarity, the brightness and fidelity of colors, as well as environmental protection, washability, sun resistance and hand feel, have been greatly improved. It is a popular printing and dyeing process that is currently respected and the products move towards high-end.