Factors affecting the fading of plastic products

According to the data and practice proved that there are many factors affecting the fading of plastic products, the fading of plastic products with color and pigment, dye light resistance, oxygen resistance, heat resistance, acid and alkali resistance and the characteristics of the resin used. In the production of masterbatch of pigment, dye, surfactant, dispersant, carrier resin and anti-aging additives for the above performance of a comprehensive evaluation, can be selected, the following is the conventional influence of product discoloration reasons and logistics performance, for dear friends reference.

1. Light fastness

The light fastness of colorants directly affects the fading of products. For outdoor products exposed to strong light, the light fastness (light fastness) grade of colorants used is an important index. If the light fastness grade is poor, the products will quickly fade in use. So this is why such as the anti-dazzle board on the highway, water horse, etc., after a few years after the sun exposure color will become pale, but generally in the blow molding, will add a quantitative anti-UV ingredients, to ensure the durability of the product color retention time.

2. Heat resistance

The thermal stability of pigments refers to the degree of thermal weight loss, discoloration and fading of pigments at the processing temperature. Inorganic pigments are composed of metal oxides and salts, with good thermal stability and high heat resistance. Organic pigments, on the other hand, change their molecular structure and decompose a little at a certain temperature. In fact, we need in the production process, if the plastic products need to be heated at high temperature, we need to choose more heat-resistant pigments to ensure the color change, fade, and ensure the overall appearance of the product.

3. Antioxidant

Some organic pigments gradually fade due to the degradation of macromolecules or other changes after oxidation. This process is one of high temperature oxidation in processing and the other of oxidation when it encounters strong oxidants (such as chromate in chromium yellow). When lake and azo pigments are mixed with chrome yellow, the red color will gradually fade.

4. Acid and alkali resistance

Colored plastic products fade and colorant chemical resistance (acid and alkali resistance, oxidation resistance reducibility) related. For example, molybdenum chrome red is resistant to dilute acid, but sensitive to alkali, and cadmium yellow is not acid-resistant. These two pigments and phenolic resins have strong reducing effect on some colorants, which seriously affect the heat resistance, weather resistance and fading of colorants.