What are the factors that affect the fading of EVA products? I believe that many people are very worried about such problems with EVA products. In fact, EVA appears in home life as the core material now. It often acts as sound insulation material, floor material, cushioning material, etc. in decoration projects. EVA material has many advantages as a carpet, such as good earthquake resistance, waterproof, anti-electric, etc. So today Dongyang Yirong Luggage will summarize the four major reasons for the fading of plastic EVA products:
Factors that affect the fading of plastic EVA products. The fading of plastic colored products is related to the light resistance, oxygen resistance, heat resistance, acid and alkali resistance of pigments and dyes, as well as the characteristics of the resin used. According to the processing conditions and use requirements of plastic products, the above-mentioned properties of the required pigments, dyes, surfactants, dispersants, carrier resins and anti-aging additives should be comprehensively evaluated when producing masterbatches before they can be selected.
Four major reasons for the fading of EVA products:
1. Acid and alkali resistance The fading of colored plastic products is related to the chemical resistance of the colorant (acid and alkali resistance, oxidation and reduction resistance)
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 resin have a strong reducing effect on some colorants, which seriously affects the heat resistance and weather resistance of the colorant and causes fading.
2. Antioxidant properties Some organic pigments gradually fade after oxidation due to macromolecular degradation or other changes
This process is high-temperature oxidation during processing and oxidation when encountering strong oxidants (such as chromate in chrome yellow). After the color lake, azo pigment and chrome yellow are mixed, the red color will gradually fade.
3. The thermal stability of heat-resistant pigments 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. However, 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℃. When selecting colorants, on the one hand, we should pay attention to the heat resistance of the pigment, and on the other hand, we should consider the heat resistance time of the pigment, which is usually required to be 4-10rain.
4. Light resistance The light resistance of the colorant directly affects the fading of the product
For outdoor products exposed to strong light, the light resistance (sun resistance) level requirement of the colorant used is an important indicator. If the light resistance level is poor, the product will fade quickly during use. The light resistance level selected for weather-resistant products should not be lower than level 6, preferably level 7 or 8, and level 4 or 5 for indoor products. The light resistance of the carrier resin also has a great influence on the color change. After the resin is irradiated by ultraviolet rays, its molecular structure changes and fades. Adding light stabilizers such as ultraviolet absorbers to the masterbatch can improve the light resistance of the colorant and colored plastic products.
The four major reasons for the fading of plastic EVA products are shared here. Paying attention to the above points can avoid adverse factors such as fading of EVA products; due to the advantages of EVA materials, it is now more and more widely used in daily life.
Post time: Sep-26-2024