Asia Billion is a precision (Acrylonitrile Butadiene Styrene) ABS plastic injection molding company in Hong Kong and China , after 10 years development, we equip with high quality imported mould making and injection molding machine. we also have the high skilled engineering team and workers. it can help our customer realize their project with faster lead time , stable excellent quality and competitive price. If you want to want to long time excellent plastic injection molding supplier, please contact us freely.
Asia Billion Plastic Injection molding plant overview:
Asia Billion Injection Moulding quality control:
Here Asia Billion would like to share our decades years' experience for the ABS plastic molding processing key points
1. Product and mold design
The product wall thickness requirements are uniform, and the wall thickness difference of ABS products should be controlled within 25% to prevent local stress concentration caused by excessive wall thickness difference. The root of the weaker column needs to be increased by the R angle or additional ribs to prevent the column from breaking.
Buckle design, the root of the buckle needs to be inverted R angle, the size of the R angle depends on the wall thickness of the product, the R angle and the wall thickness ratio should be above 0.3, as the ratio increases, the internal stress gradually decreases, but also Consider the shrinkage of the surface of the product. The design of the mold cooling channel should ensure the uniformity of cooling and avoid the internal stress caused by uneven cooling and shrinkage.
2. Material drying
Generally, ABS resin absorbs moisture in the air during storage and transportation. The water absorption rate varies with the humidity of the air, generally between 0.2 and 0.4%. Therefore, the material must be sufficiently dried to reduce the moisture content of the material to less than 0.05%. It is better to be below 0.02%, otherwise surface defects such as water splash and silver wire may occur. The heat-resistant ABS resin has a drying temperature higher than that of ordinary ABS, usually 80-95 ° C, and a drying time of 3-4 hours.
3. Injection molding temperature
The molding temperature is a parameter that needs special attention during the processing of heat-resistant ABS. The setting is based on ensuring the full plasticization of the heat-resistant ABS. The range of the ABS plastic injection molding temperature recommended by the supplier should be used as much as possible. The increase will significantly reduce the viscosity of the heat-resistant ABS, increase the fluidity of the resin, and make the flow distance longer, to ensure that the material has sufficient filling ability.
4. Holding pressure and time
For ABS, the setting of holding pressure and time is reasonable, which directly affects the internal stress of the part. The increase of holding pressure will make the molecular gap smaller, the range of the segment movement will be reduced, the volume of the melt will be reduced, the density will become larger, and the force between the molecules will increase, which can improve the shrinkage and internal quality of the product, but it will lead to internal pressure. The stress becomes large, so the lower holding pressure should be selected as much as possible under the premise of ensuring the appearance quality of the product.
The holding time is set according to the time when the gate is solidified by cooling, and the screw is pushed forward to no longer apply pressure to the molded article. If the holding time is too long, the material is easily filled too much, the molecular gap becomes small, and the internal stress becomes large; the holding time is too short, the product is prone to shrinkage, and the size is unstable. The holding time setting should be the best holding time when the product weight does not change any more.
5. Mold temperature
It is recommended to use a mold temperature machine to control the mold temperature during molding of ABS. The recommended mold temperature is 60-80 °C. Higher mold temperatures tend to produce good flow, higher weld line strength, and lower product internal stress, but the molding cycle is prolonged. If the mold temperature is lower than the recommended one, it will lead to excessive stress in the product, which will reduce the performance of the product, and may cause undesirable phenomena such as cracking of the product, cracking of the screw hole or cracking of the paint.
If you want to find a good partner for ABS plastic injection molding and injection mold project, please contact us freely for any RFQ or question.