Precautions for the production of heat transfer printing film

The heat transfer printing film can be printed on the printing machine after the materials are fully prepared. Generally, the release layer, printing layer and adhesive are coated and printed on a unified gravure printing machine. Unwinding: Mount the base film in the center of the unwinding roller, pass it between the printing roller and the printing plate cylinder, and then pass through the constant tension traction roller and enter the rewinding roller.

Adjust the paper feeding force according to the diameter of the roll, and set different drying temperatures according to the different materials to be coated. Distribute the release agent first, pour it into the coating tank and stir evenly. Turn on the gravure printing machine for coating. The coated substrate film is dried on the drying equipment. The drying temperature can be based on the temperature required by the release agent or Set according to the data provided by the manufacturer. The release agent has a very short curing time on the surface of the base film, but to achieve a better transfer effect, the solvent must be allowed to evaporate completely before preparing to apply the ink. Therefore, the drying temperature can be appropriately higher, or in 2-4 colors. The group is boring. The coating thickness of the release agent should be controlled at about 5 μm. It should not be too thick or too thin. If it is too thick, the release layer will easily fall off the base film. If it is too thin, the printing layer will not be completely transferred during thermal transfer.

 The printing layer of thermal transfer film is generally gravure printed. Pass the base film roll coated with release agent through the middle of the impression roller and the printing plate roller. The printing plate roller rotates in the ink tank to print out the graphics and text, and then passes the drying equipment to the printed The ink layer is dried to accelerate the drying speed. The drying temperature of thermal transfer ink is selected according to its solvent. If the solvent is fast-drying toluene, the drying temperature can be appropriately lowered; if it is slow-drying xylene, the drying temperature should be increased. At the same time, please note that the printing color sequence of the thermal transfer film is opposite to the general printing color sequence, that is, the ink with high transparency is printed first, then the ink with low transparency is printed, and finally a layer of white ink is printed as needed. The function of opaque white ink is to cover the color of the substrate itself, so that the level and color of the graphics and text transferred to the colored object are not affected.

To avoid damaging the graphics and text on the printed layer, the adhesive layer should be applied when the printed layer is completely dry. The adhesive layer can be directly coated on the last color group of the gravure printing machine. The coated substrate film is then dried. The drying temperature is determined according to different substrate films. It is controlled by the rewinding air shaft and the paper release The axes are the same, and the winding force is controlled by the winding motor to control the traction force of the traction roller, which is generally the same as the tension at the paper release point, so that the machine can operate normally. When one reel is finished, it can be cut and then rolled onto another reel. Thermal transfer film rolls will be cut into products of different widths as required. In order to save costs, thermal transfer graphics and text are usually evenly distributed on a printing plate according to size, and then cut when used. At the same time, it is important that the cutting machine must have automatic correction equipment, otherwise it will affect the overall effect of the graphics and text.

 During the printing process, release agent, ink and adhesive must be replenished at any time, and the roll film must be placed on the paper feeding mechanism in time to ensure continuous and normal printing. It is also necessary to regularly check the coating status of each material of the thermal transfer printing film, whether there are white spots, dirt, streaks and other defects on the printed sheet, and to promptly remove rough printing defects.