Some preparations before printing for heat transfer printing film manufacturers

The heat transfer film is generally composed of four layers: the substrate (blank transparent film) layer, the release layer, the printing layer, and the adhesive (glue) layer. Base layer: refers to the carrier coated with release agent, ink, and adhesive, which requires temperature resistance, pressure resistance, and small tensile deformation. Generally, PET and OPP films are commonly used. Release layer: It is a layer of release agent coating that maintains a solid state at room temperature and can melt at a certain temperature. It can quickly detach from the substrate layer without any adhesive residue. The release agent is the key to separating the printing layer from the substrate layer and transferring it to the surface of the substrate. It requires good wear resistance, which can protect color ink, reduce the intensity of ultraviolet radiation, reduce the invasion of unfavorable factors in the air on the ink, extend the service life of the ink, and buffer the adhesion between the substrate film and the printing layer.

Printing layer: This layer is the fundamental foundation for the aesthetic texture of transfer products. The printing layer has various colors and patterns. Especially the images and texts obtained through intaglio printing can effectively reflect the delicate graphics and texts, making their packaging and decoration more effective. Adhesive layer: Its basic performance is to have a high bonding force with the surface of the substrate, ensuring a solid bonding between the printing layer and the substrate surface. This layer of adhesive must match the printing material. Different adhesives, due to their different chemical composition, have a significant difference in adhesion to the substrate. Selection should be based on different substrates.

Before starting the heat transfer printing process, it is necessary to carefully analyze and study the customer's requirements, and then proceed according to the printing process steps. Before starting heat transfer printing with patterned film, it is necessary to carefully analyze and study according to the requirements, and then proceed according to the printing process steps. Preparation of substrate film: There are various carriers for heat transfer printing, with PET being widely used. It has the characteristics of good dimensional stability, uniform tension, good heat resistance, and good release performance. Especially in the reproduction of color gradient manuscripts, it has obvious advantages. The specifications of the film, such as width, thickness, size, and brand, shall be selected according to the manufacturer's requirements. At the same time, it is necessary to check the flatness of the film and whether there are any "protruding ribs" or "ruffled edges" in the cylinder that do not meet the quality requirements.

Low viscosity transparent resin with release, film-forming, and adhesive properties. Due to the fast solvent evaporation rate in the release agent, attention should be paid to controlling the viscosity during the coating process, that is, controlling the solid content of the release agent. The solid content is generally controlled at around 23%. If the solid content is below 19%, the heat transfer printing effect of the release agent after coating is not ideal. At the same time, pay attention to the transparency of the release agent, otherwise it will affect the effect of the printing layer.

Heat transfer printing ink belongs to gravure printing ink, and the drying of the ink mainly depends on the volatilization of the solvent. After determining the substrate film, appropriate ink is selected based on the purpose of the printed product and the properties of the printing material or according to the requirements of the construction order. Check the fineness, viscosity, hue, coloring power and other indicators of the ink to see if they all meet the printing quality requirements for the ink. The adhesive used for heat transfer printing is hot melt adhesive, which is a colorless transparent or light yellow viscous liquid. After coating and drying into a film, the film is transparent. It has excellent composite fastness and superior flexibility on the surface coated with release agent and ink, abrasion resistance, water and acid resistance