Keywords: thermal transfer technology development and application introduction: thermal transfer technology is mainly to print patterns and other patterns on heat-resistant adhesive paper, and through technical measures such as pressure and heating to print the patterns and patterns of the oil film layer on the finished product A new type of technology in materials. Thermal transfer technology is a kind of special technology. At present, this technology has been widely used in textiles, porcelain, containers, commodity labels, packaging and other logos for printing, transfer printing and other fields. This article mainly introduces thermal transfer technology briefly, and specifically analyzes the development and application of thermal transfer technology.
1. Introduction to thermal transfer technology
Thermal transfer is also called in-mold decals, in-mold labels, in which the label thermally bonds the functional layer and carrier layer of the label to each other under the action of the molding pressure of the hot-melt plastic and the heat energy, and adheres to the substrate Surface, and there will be no detachment.
(1) Classification of thermal transfer technology
Thermal transfer technology can be divided into sublimation transfer and hot press transfer according to the type of oil film used. Hot press transfer is mainly a technical measure that uses a plastic molding machine to fully use heat pressure and thermal energy to achieve printing during the plastic molding process, and this heat transfer technology is concave inlaid on the substrate after the transfer of the label. Inside the surface of the object. Sublimation refers to the phenomenon that solid matter is directly transformed into gaseous state under certain conditions of pressure and temperature. Dye sublimation transfer mainly refers to the process in which the dye in the sublimation ink directly transforms from the solid state to the gas state, and the dye is condensed after sublimation. Hua is transformed into a solid state on the surface of the substrate. Dye-sublimation transfer technology is also realized by heating and pressurizing heat transfer methods. Dye-sublimation transfer technology is also called vapor-phase transfer.
Thermal transfer technology can be divided into flat printing, screen printing, embossing, gravure ribbon printing and inkjet printing from the printing method [1]. The transfer material can be divided into plastic film, plastic board, ceramic, fabric and metal coating layer. From the substrate can be divided into thermal transfer plastic film and thermal transfer paper.
(2) Features of thermal transfer technology
The pattern and logo on the transfer film are transferred to the surface of the product by the heat transfer machine, so that the formed oil film layer and the surface of the transferred product are fused together, which not only has good adhesion, but also wears resistance. The light fastness is very good, and it plays an important role in improving the grade of the product. The characteristics of the thermal transfer technology are as follows:
①The thermal transfer technology has fewer processes, simple equipment, high production efficiency, low cost, and high added value of the product.
②Heat transfer technology has no environmental pollution, green printing technology, and meets international non-toxic standards.
③The products produced are not only bright in color, high gloss, strong adhesion, but also good in corrosion resistance, alcohol resistance, aging resistance, impact resistance and abrasion resistance [2].
2. The development of thermal transfer technology
As early as the early 1960s, thermal transfer technology began to be used in the textile industry and footwear industry. Then, with the rapid development of high technology, thermal transfer technology has become more and more widely used.
The thermal transfer ink is usually printed on paper or plastic film by screen printing to make a thermal transfer sheet. The printed transfer sheet and the textile are heated and pressurized together, and the dye on the transfer sheet will be sublimated and transferred to the textile in a gas phase. In addition to textiles, it can also be transferred to ceramics, metals and other products.
Nowadays, the new technology of digital transmission has injected a new meaning into the thermal transfer. Thermal transfer technology and level have been further expanded and improved. Thermal transfer technology widely uses computers for image processing and design. It allows you to take a small order, that is, 1-20 pieces (direct screen printing costs are too high to be considered). With the development of digital sublimation transfer printing, thermal transfer has opened up a new personalized clothing market, such as mouse pads, cups, T-shirts, ceramic tiles, glass and a wide variety of hard surface decorations and even 3D pattern products.
Third, the application of thermal transfer technology
The development of society and the advancement of science and technology have made thermal transfer technology no longer unique to large-scale mass production factories. Self-designed and self-expression personalized image art is entering the common people's life with the help of thermal transfer technology. Life, from wear to daily necessities, household goods, and art supplies, it can be said that wherever there are products, you can see the shadow of heat transfer technology.
However, not all products can be printed with thermal transfer, which involves factors such as the heat resistance, smoothness,... and other factors of the product. Due to the continuous advancement of technology, the main applications of thermal transfer are currently:
1. Heat transfer printing of clothing decoration cloth, curtain cloth, sofa cloth, umbrella cloth, handbag, carpet cloth, toy cloth, etc.;
2. High temperature resistant plastic materials or surface thermal transfer decoration of plastic materials treated by spraying, baking varnishing, electrophoresis, etc.;
3. Metal decorative panels, security doors, metal molded doors, aluminum profiles, metal ceilings, curtains, rails, metal pipes, handicrafts, hardware furniture and other metal surface heat transfer decorations after spraying, baking, electrophoresis and other treatments;
4. The front and back of various natural leathers, PU or PVC surfaces, such as PU or PVC coated fabrics.
Finally, take the flatbed machine used in life to transfer images to clothes as an example to illustrate the specific production steps and processes of thermal transfer products:
The first step: Print the image through a color inkjet printer.
Step 2: Put the printed pattern aside first, and start the transfer after about 15-20 minutes. When transferring, when putting the printed image on the clothes, the pattern should be facing down, and then adjust the time according to the transfer requirements of the thermal transfer equipment (usually 20 seconds), and close the heating plate of the equipment ( Note: The cotton T-shirt should be sprayed with a little darkening agent on the printing part before transfer, and it must be dried before thermal transfer. Its function is to change the color of the ink through thermal pressure and improve the bright effect of the ink on the clothes. ).
The third step: In order to prevent the clothes from turning yellow due to the high temperature, a piece of interlining cloth can be put on the clothes for thermal transfer. After the time alarm of the thermal transfer equipment, lift up the heating sheet, quickly uncover the pattern paper, take out the clothes, and turn off the power supply of the equipment.
Fourth step: Finally, when the temperature of the clothes cools down, fold the bag, and then the entire heat transfer printing can be completed, and the finished product can be made.
Fourth, summary
Thermal transfer technology has been widely used in various fields. Thermal transfer technology can not only solve the problems existing in the traditional printing process, but also has production efficiency, cost saving, long storage time, strong adhesion, and has great influence on the production management of products and workpieces. Important role. And with the rapid development of science and technology, thermal transfer technology will quickly move towards the era of digital printing, which will further promote the development of thermal transfer technology. Therefore, this technology will win the attention of the market, and this technology will have a wide range of application prospects.
