Heat transfer printing film refers to the special functional printing film with adhesive, which is separated from the carrier film together with the release layer under the combined effect of temperature and pressure, and firmly bonded on the substrate surface.
Heat transfer film is generally composed of four layers: substrate (blank transparent film), release layer, printing layer and adhesive (glue) layer
Substrate layer: the carrier coated with release agent, ink and adhesive, which is required to be temperature resistant, pressure resistant and small tensile deformation. Pet and OPP films are commonly used.
Release layer: it is a layer of release agent coating, which can keep solid state at normal temperature, melt at a certain temperature, and can be quickly separated from the base layer without adhesion residue. The release agent is the key to complete the separation of the printing layer from the substrate and the transfer to the substrate surface. It is required to have good wear resistance, protect the color ink, reduce the UV radiation intensity, reduce the invasion of adverse factors on the ink in the air, extend the service life of the ink, and buffer the adhesion of the substrate film and the printing layer.
Printing layer: this layer is the basis of the aesthetic quality of transferred products. The printing layer has various colors and patterns. In particular, the image and text obtained by intaglio printing can well reflect the delicate image and text, and make the packaging and decoration effect more perfect.
Adhesive layer: its basic performance is to have a high adhesive force with the substrate surface to ensure that the printing layer and substrate surface are firmly combined. This layer of adhesive must match the substrate. Different adhesives, due to the different chemical composition, and substrate adhesion is very different. It should be selected according to different substrate.
Before the start of printing, the heat transfer film printing should be carefully analyzed and studied according to the requirements of customers, and then carried out according to the printing process steps.