What is Sublimation Printing Process all about?
Sublimation transfer printing firstly uses a printing method to print a special dye on a transfer paper, and then heats and pressurizes it to transfer the dye to the fabric. Specifically, it is based on the sublimation characteristics of disperse dyes. It selects disperse dyes with a temperature range of 180 ~ 240 ° C, mixes them with the paste to make color inks, and prints the inks, according to different requirements of patterns, onto the transfer paper, the transfer paper printed with patterns is then in close contact with the fabric, and processed on a transfer printing machine at 200 ~ 230 ° C for 10 ~ 30s. The dye is then transferred from the printed paper to the fabric, and enters the interior of the fabric through diffusion, finally achieving the purpose of coloring.
In summary, the sublimation transfer technology has the following four characteristics:
The printing effect is good.
The sublimation fabric printed with sublimation transfer technology has fine patterns, bright colors, rich and clear layers, high artistry, and strong three-dimensionality. It is difficult to print by ordinary methods, and it can print photographic and painting style patterns.
Prints are soft to the touch and have a long life.
The biggest feature of sublimation transfer is that the dye can diffuse into polyester or fiber, and the printed product feels very soft and comfortable, and the presence of the ink layer is basically not felt. In addition, because the ink is dried during the transfer process, the life of the image is as long as the life of the garment itself, and there will be no wear and tear on the printed graphics, affecting the beauty of the fabric.
The process is simple, the equipment investment is small, the flexibility is strong, and the rate of certified products is high.
During sublimation transfer process, multiple sets of patterns can be realized without alignment. According to the personalized needs of customers, samples can be printed in a short time to meet the personalized needs of customers.
Save resources and protect the environment.
Unlike traditional fabric printing, thermal sublimation transfer printing does not require the post-treatment processes such as steaming and washing, which saves a lot of water resources and no sewage discharge, which can save resources and protect the environment.
Factors affecting the quality of thermal sublimation transfer?
Sublimation transfer ink is the key material of sublimation transfer technology. It is mainly composed of disperse dye, linker, solvent and a small amount of additives. Dyes require good sublimation transfer and permeability to achieve a certain fastness index. The molecular weight is 230 ~ 380 and the temperature is 180-240 ℃. The main feature of thermal sublimation transfer is that the dye can diffuse into the fabric fibers and adhere well to the fabric fibers. Therefore, good quality sublimation inks have vivid colors, strong stability, and good transfer effects.
The sublimation transfer process requires that the temperature be controlled within the range of 180 ~ 230 ° C, and the transfer time is about 10-30 seconds. At the same time, reasonable allocation of temperature and time must be paid attention to.
Pressure is also one of the important parameters of the thermal sublimation transfer process. Taking fabric sublimation transfer printing as an example, If the pressure is too small, the gap between the fabric and the transfer paper is large, the yarn is round, and a large number of ink gas molecules collide with the air. At the same time, the ink is also easy to bleed, the lines become thicker, the patterns are blurred, and the visual effect becomes worse; if the pressure is appropriate, the yarn is flat and the gap between the fabric and the transfer paper is suitable and the transfer effect is good, the pattern is clear, and the lines are smooth and fine; if the pressure is too large, it is easy to cause deformation, fluff and morphological changes of heavy fabrics, causing shortcomings such as rough feel. Therefore, it is very important to control the transfer pressure for the printed fabrics with clear visual effects and beautiful fabrics.
In addition to ink, temperature, time, and pressure, which will affect the quality of thermal sublimation transfer, in the actual production process, there are some considerations that deserve our attention. The first is the selection of transfer paper. Suppliers with stable quality and high credibility should be the first choice. Secondly, the color after printing is very different, the dye ink generally looks dark and matte before the transfer. It needs high temperature of about 200 ℃ to reduce the color. In this way, it is necessary to proof before printing. Finally, during thermal transfer, make sure that the hot-pressed surface, the transfer paper, and the surface of the substrate are in close contact with each other without gaps, otherwise the phenomenon of blurred transfer graphics may occur.