What are the differences between different plastic materials in Injection Molding?
Publish Time: 2024-06-22
In the Injection Molding process, the selection of plastic materials is crucial, which directly affects the performance, appearance and production cost of the product. Different plastic materials show significant differences in the Injection Molding process.
First, the fluidity and melting temperature of plastics are key factors to distinguish different materials. For example, PP (polypropylene) has high fluidity and a wide processing temperature range (160-175℃) due to its semi-crystalline characteristics. In contrast, although PS (polystyrene) has good fluidity, its heat resistance is poor (60-80℃), and the processing temperature is usually set at 185-215℃.
Secondly, the hardness and toughness of plastics are also important distinguishing points. ABS (acrylonitrile-butadiene-styrene copolymer) is known for its comprehensive properties of "hard, tough, and steel", and its hardness and toughness are better than PS. Although PS has high hardness, it is brittle and prone to internal stress cracking.
In addition, the hygroscopicity of plastics and the drying requirements before processing are also different. For example, PS and PP have low hygroscopicity and usually do not require drying, while ABS must be fully dried and preheated before molding due to its hygroscopic properties.
During the injection molding process, the shrinkage and molding shrinkage of different plastics will also vary. For example, the molding shrinkage of PS is generally between 0.004 and 0.007, while the shrinkage of ABS is lower (0.60%).
Finally, the application fields of different plastics are also different. PP is widely used in water supply pipes, household pipes and other fields due to its excellent chemical resistance and insulation; while ABS is widely used in automobiles, electrical appliances and other fields due to its good comprehensive performance.
In summary, different plastic materials show significant differences in injection molding, which are not only reflected in physical and chemical properties, but also in processing and application fields. Therefore, when selecting injection molding materials, it is necessary to make comprehensive considerations based on specific product requirements and process conditions.
