How to solve the dispersion problem from the masterbatch formula? How does the ABS home appliance industry do it? The main characteristic indicators of ABS home appliance color masterbatch
Index 1. Heat resistance
The temperature of the molten metal during injection molding is relatively high, and the residence time in the high-temperature cylinder is also relatively long. Therefore, in order to prevent the damage caused by high temperature, the colorant used needs to have high heat resistance. Especially for large products, products with complex structures, and products with hot runner cavities, set the injection temperature higher than usual. Therefore, it is necessary to fully consider the different requirements of each product and choose a colorant with a relatively high heat resistance.
Indicator 2. Dispersion
The basic requirements for the appearance of plastic injection molded parts are bright colors, high gloss, and no color spots. Regarding the hue, in addition to the factors of the mold itself, the dispersion of the solids contained in the product formula is also an important factor.
The injection molding machine itself has a very limited dispersing effect on the color masterbatch. Poor dispersibility of the color masterbatch will produce many color spots on the surface of the product, which will affect the quality of the product.
Index 3, resistance to yellowing
Yellowing occurs when the polymer is exposed to sunlight or ultraviolet light for a long time, or the color turns yellow due to heat, oxygen, stress, trace moisture, impurities, improper workmanship and other reasons. ABS resin is a terpolymer of polyacrylonitrile, butadiene and styrene, in which the styrene segment is extremely sensitive to oxygen, and the molecular weight will decrease even in the presence of trace oxygen at the processing temperature; the butadiene chain is more sensitive to oxidation , manifested as crosslinking and decreased elasticity, and color change; acrylonitrile chains are sensitive to thermal stress, forming a conjugated structure, which absorbs visible light and discoloration occurs, and the final result is more complicated due to the interaction of different components of the oxidized chain .
With the development of my country’s home appliance industry, the share of home appliance exports has increased year by year. The export of home appliances generally takes a long time for long-distance transportation. They are not products exported to the Middle East and tropical regions. ABS plastic products are prone to yellowing and other problems.
Indicator 4. Migration
Most ABS home appliances have contact with food and direct contact with other products. Once the problem of transfer occurs, it will cause cross-contamination of color at least, and cause safety problems when using the product. Please do not neglect it. According to the practical needs of the product, for sensitive products, the use of pigment products with migration potential should be avoided.
Index 5, mechanical properties
ABS home appliance color masterbatch also needs to meet the mechanical performance test in the technical index of QB/T2894—2007 “polyacrylonitrile-butadiene-styrene (ABS) color masterbatch”, in which the impact strength retention rate is 88%, and the tensile strength retention rate is 88%. 90%, and some varieties need to be tested for drop hammer impact performance.
Index 6. Security
ABS home appliance injection molding products generally must meet the European Union’s Electrical and Electronic Products Hazardous Substance Control Directive “RoHS Directive”, the US Electrical Equipment Environmental Protection Design Act (EDEE Act, referred to as H.R.2420), China) “Electronic Information Products Pollution Control Management Measures”), ” Restricted use of hazardous substances in electrical and electronic products “).
According to these standards, the content of lead, mercury, hexavalent chromium, polybrominated biphenyls ( PBB ) and polybrominated diphenyl ethers ( PBDE ) in electrical and electronic products shall not exceed 1000 (/kg, and the content of cadmium shall not exceed 100 (/kg). ABS Home Appliance Color Masterbatch
ABS masterbatches for home appliances usually use ABS or AS as the carrier, and should meet the requirements of the technical indicators of ABS masterbatches stipulated in QB/T2894-2007.
