The quality requirements of the plastic film coating process for the PPGI Colour Coated Sheet are: the thickness directly affects the light transmittance, refraction, film fastness, mechanical strength, etc. According to the film’s performance and the purpose of use, the thickness of the film coating is 0.01-0.01mm Between is appropriate. It must be treated by corona or other methods, and the surface tension inside should reach 4Pa to have better wettability and adhesion performance. The surface treated by corona should be uniform. The higher the transparency, the better to ensure the best clarity of the covered print.
Transparency is expressed by light transmittance, that is, light transmittance, that is, the percentage of transmitted light and transmitted light. The light transmittance of PET film is generally 88%-90%. The light transmittance of several other films are usually between 92% and 93%. Good light resistance, that is, it is not easy to change color under long-term exposure to light and has specific mechanical strength and flexibility. The mechanical strength of the film includes technical indicators such as tensile strength, elongation at break, elastic modulus, impact strength, and folding times.
The geometric dimensions should be stable, which are often expressed by indicators such as hygroscopic expansion coefficient, linear expansion coefficient, and heat distortion temperature. The lamination film should be in contact with solvents and adhesives. It must have specific chemical stability. Appearance The film surface should be flat, without unevenness and wrinkles, and the film should be free of bubbles, shrinkage cavities, pinholes and pitting, etc., and the film surface should be free of dust, impurities, grease, and other pollution. The thickness is uniform, and the vertical and horizontal thickness deviation is slight. Due to the limited adjustment ability of the laminating machine, it is also required that the rewinding be neat and the two ends are tight and tight to ensure uniform glue application.