Views: 111 Author: Site Editor Publish Time: 2022-10-10 Origin: Site
You can see the colors of various cosmetic plastic bottles on the market. Do you know how difficult it is for manufacturers to overcome the problem of fading cosmetic plastic bottles?
Product fading is often encountered when making cosmetic bottles. There are many factors that affect the fading of cosmetic plastic bottle products. The fading of plastic colored products and the light resistance of pigments and dyes, oxygen resistance, heat resistance, acid and alkali resistance, and The characteristics of the resin used are related. In the production of color masterbatch, the required pigments, dyes, surfactants, dispersants, carrier resins and anti-aging additives can be used after comprehensive evaluation. The following are the factors that conventionally affect the discoloration of cosmetic plastic bottles during production.
The fading of colored plastic products is related to the chemical resistance of the colorant (acid and alkali resistance, oxidation-reduction resistance). For example, molybdenum chrome red is resistant to dilute acid, but is sensitive to alkalis, and cadmium yellow is not acid resistant. These two pigments and phenolic resins have a strong reducing effect on certain colorants, which seriously affects the heat resistance and weather resistance of the colorants and causes fading.
The thermal stability of a pigment refers to the degree of thermal weight loss, discoloration, and fading of the pigment at the processing temperature. Inorganic pigments are composed of metal oxides and salts, with good thermal stability and high heat resistance. The pigments of organic compounds will undergo molecular structure changes and a small amount of decomposition at a certain temperature. In fact, we need in the production process. If it is a plastic product that needs high temperature heating, we need to choose a more heat-resistant pigment to ensure color change and fading, and to ensure the overall appearance of the product.
Some organic pigments undergo macromolecular degradation or other changes after oxidation and gradually fade. This process is high temperature oxidation during processing, and oxidation when encountering strong oxidants (such as chromate in chrome yellow). After the lake, azo pigment and chrome yellow are used in combination, the red color will gradually fade.
The light fastness of the colorant directly affects the fading of the product. For outdoor products exposed to strong light, the light fastness (light fastness) level requirement of the colorant used is an important indicator. The light fastness level is poor, and the product will quickly fade during use. So this is why, for example, anti-glare boards on highways, water horses, etc., after a few years of use, the color will fade after exposure to the sun, but generally when blow molding, a certain amount of anti-UV ingredients are added to ensure Persistence of product color retention time.