Plastic packaging materials to replace the traditional material has become a reality, plastic packaging from the quality, color, sealing and other aspects are constantly improving, and plastic packaging of environmentally friendly ink are demanding, we analyze together, on the plastic packaging fade problem is how of:
Lightfastness of the coloring agent directly affect the fade of products, by the strong light of outdoor products, the colorants used in light (light) grade requirements is an important indicator, poor light level, the product will be used soon fade. Weathering products used in light-resistant grade should not be less than six, the best choice of seven, eight, indoor products optional four or five. The photographic properties of the carrier resin also have a great effect on the color change, and the molecular structure of the resin after UV irradiation is faded. The addition of a light stabilizer such as an ultraviolet absorber to the masterbatch improves the light resistance of the colorant and the colored plastic product.
The thermal stability of the heat-resistant pigment refers to the degree of thermal loss, discoloration and discoloration of the pigment at the processing temperature. The composition of inorganic pigments is metal oxide, salt, good thermal stability, high heat resistance. While the organic compounds of the pigment at a certain temperature will occur in the molecular structure of the changes and a small amount of decomposition. In particular, PP, PA, PET products, processing temperature above 280 ℃, in the selection of coloring agent on the one hand to focus on the heat resistance of pigments, on the one hand to consider the heat-resistant pigments.
Antioxidant Some organic pigments are oxidized after oxidative degradation of macromolecules or other changes occur. This process is the high temperature oxidation in the process and the second is the oxidation of the strong oxidants (such as chromate in chrome) The Lakes, azo pigments and chrome yellow mixed use, the red will gradually diminish.
Acid-resistant coloring of plastic products and coloring of the chemical resistance (acid and alkali resistance, redox resistance). Such as molybdenum chromium red resistant acid, but sensitive to alkali, cadmium and yellow is not acid, these two pigments and phenolic resin on some colorants from the strong reduction effect, seriously affect the colorant heat resistance, weatherability and fade.
