Oxidáciu papiera na razenie za tepla po razení za horúca ovplyvňuje najmä substrát na razenie za tepla. Vo všeobecnosti je pH substrátu príliš vysoké a papier na razenie za horúca je pokrytý kovovou hliníkovou vrstvou. Reakcia medzi hliníkom a kyslou-zásadou je pomerne rýchla, takže je dobrá po lisovaní za tepla. , po určitom čase sa zafarbí a zoxiduje a čím vyššia je teplota, tým je to vážnejšie.
Z hľadiska štruktúry možno bronzovací papier rozdeliť na:
1. The base layer
The main function is to support the coatings on it, which is convenient for continuous hot stamping during processing. The base layer of the hot stamping paper is made of 12um or 16um thick PET film, which has the characteristics of tensile strength and high temperature resistance. During the hot stamping process It will not be deformed or broken due to hot stamping heating. The base layer determines the thickness.
2. Peel layer
The peeling layer is generally formed by coating with a silicone resin or the like. The main function is that after hot stamping (heating and pressing), the color material, aluminum and adhesive layer can be quickly separated from the polyester film and be transferred and bonded on the surface of the hot stamped object. The peeling layer must have good shedding performance, otherwise the hot stamped graphics will be blurred, exposed, white, etc., which will affect the quality of the hot stamped product. The peel layer determines the size of the hot stamping area.
3. Color layer
The main components of the color layer are synthetic resins and dyes with suitable film-forming properties, heat resistance and transparency. Commonly used resins are polyurethane, nitrocellulose, melamine formaldehyde resin, modified rosin resin, etc. During production, the resin and dye are dissolved in an organic solvent to form a color paste, which is then coated and dried. There are two main functions of the color layer, one is to display the color; the other is to protect the aluminized layer graphics and text stamped on the cover or other surfaces from being oxidized.
The color of anodized aluminum foil is golden, orange, gray, red, blue, green, etc. The color of the color layer is given luster after passing through the aluminized layer, and the color changes to a certain extent, such as yellow after aluminized to gold, gray After plating, it becomes silver, etc. The coating requirements for the color layer are fine and without any small particles, so as to avoid trachoma, and the coating is uniform and consistent. For the parts that are prone to color difference, the way to check the color difference is to stick it with transparent tape and look at the back. At this point, the bronzing paper is very rich in color, full of color and no color difference.
4. Galvanizačná vrstva
The film coated with pigment is placed in the vacuum chamber of the vacuum continuous aluminum plating machine. Under a certain degree of vacuum, the aluminum wire is melted and continuously evaporated onto the color layer of the film through resistance heating to form an electroplating layer. The main function of the electroplating layer is to reflect light, change the color of the color layer, and make it appear metallic.
5. Glue layer
The glue layer is generally a fusible thermoplastic resin, such as methyl methacrylate (ester ethyl, butyl ester) and acrylic copolymer. Other resins such as Cuban glue, shellac, rosin, etc. can also be used according to the different materials to be stamped. . The resin is dissolved in an organic solvent or made into a water emulsion, which is coated on the aluminum layer and dried to form an adhesive layer. The main function of the glue layer is to bond the hot stamping material to the object to be hot.
