Author: MULAN -Plastic Molding Manufacturer
Many products in our life are made by blow molding. Blow molding products have various colors. So what conditions will blow molding products cause the blow molding products to fade? The following is proficient in blow molding Plastic furniture custom manufacturers share with you the reasons for the fading of blow molded products! 1. Acid and alkali resistance; The fading of colored blow molded products is related to the chemical resistance (acid and alkali resistance, redox resistance) of the colorant. For example, molybdenum chrome red is resistant to dilute acid, but is sensitive to alkali, and cadmium yellow is not acid resistant. These two pigments and phenolic resin have a strong reducing effect on some colorants, which seriously affect the heat resistance and weather resistance of the colorant and cause fading. 2. Light fastness; 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) grade of the colorant used is an important indicator. If the light fastness is poor, the product will fade quickly during use. The light resistance grade selected for weather-resistant products should not be lower than grade six, try to choose grade seven or eight, and indoor products can choose grade four or five. The light resistance of the carrier resin also has a great influence on the color change, and the molecular structure of the resin caused by ultraviolet light will change and fade. Adding light stabilizers such as ultraviolet absorbers to the masterbatch can improve the light resistance of colorants and colored blow-molded products. 3. Heat resistance; The thermal stability of the pigment refers to the degree of thermal weight loss, discoloration and fading of the pigment at the processing temperature. The components of inorganic pigments are metal oxides and salts, which have good thermal stability and high heat resistance. The pigments of organic compounds will undergo changes in molecular structure and a small amount of decomposition at a certain temperature. Especially for PP, PA and PET products, the processing temperature is above 280°C. When selecting colorants, we should pay attention to the heat resistance of the pigment on the one hand, and consider the heat resistance time of the pigment on the other hand. Usually, the heat resistance time is required to be 4-10rain . 4. Oxidation resistance; Some organic pigments undergo macromolecular degradation or other changes after oxidation and gradually fade. The first process is high-temperature oxidation during processing, and the second is oxidation that occurs when encountering a strong oxidant (such as chromate in chrome yellow). After mixing lakes, azo pigments and chrome yellow, the red color will gradually fade. Proficient in blow molding 23 years experience in blow molding customization. The supporting equipment is complete, with multiple blow molding machines, injection molding machines, mold opening equipment, printing equipment, and packaging machines, which can meet the customization of different complex and special-shaped blow molding parts. The self-owned warehouse is 2000㎡, and raw materials are stored all year round, which can be quickly put into production. Long-term cooperation with brand raw material manufacturers, strict control of loss in the production process, and high cost performance.