Injection Molding Process of PC Plastic

As we all know, PC is commonly known as polycarbonate and has very good mechanical properties, so it is commonly known as bulletproof glue. PC has the characteristics of high mechanical strength, wide operating temperature range, good electrical insulation performance, good dimensional stability, and transparency. Can be used in many occasions. For example, it is widely used in electrical products, electrical instrument housings, and electronic product structural parts. On the other hand, there are many modified PC products, usually adding glass fiber, mineral fillers, chemical flame retardants, and other plastics. Another point is that PC has poor fluidity and high processing temperature, so the processing of modified materials requires a special plasticized injection structure. This is one of the characteristics of the PC.

Normally, the water absorption rate of plastic is relatively high. It must be preheated and dried before processing, and pure PC must be dried at 120°C, and the drying time must be accurate. Modified PC is generally dried at 110°C for more than 4 hours. However, the drying time cannot exceed 10 hours. It can also be viewed by other methods. Generally, the air extrusion method can be used to judge whether the drying is sufficient. The use ratio of recycled materials can reach 20%. In some specific cases, 100% recycled materials can be used, and the actual amount depends on the quality requirements of the product. Recycled materials cannot be mixed with different masterbatches at the same time, otherwise it will seriously damage the properties of the finished product. Pay more attention to this point.

Selection of injection molding machine. On what basis are raw materials usually selected? Due to cost and other reasons, PC products now use modified materials, especially electrical products, but also have to increase fire resistance, which mainly solves the characteristics of fire prevention. When molding flame-retardant PC and other plastic alloy products, the requirements for the plasticizing system of the injection molding machine are good mixing and corrosion resistance, which is difficult for conventional plasticizing screws. Therefore, it should be taken seriously when selecting products.

Design of injection mould and gate. The design must be optimized at all times. The mold temperature of common injection molded parts is 80-100℃, and glass fiber is 100-130℃, which is a very suitable temperature. Needle-shaped gates can be used for small products, and the gate depth should be 70% of the thickest part. Other gates are ring-shaped and rectangular. This is a requirement in terms of shape. The larger the gate, the better, to reduce defects caused by excessive shearing of the plastic. Efforts should be made in the gate to avoid defects. The depth of the vent hole should be less than 0.03-0.06mm, and the runner should be as short and round as possible. Only in this way can the optimization be in the best state.

The injection molding process of PC can be seen from this. Regardless of its mechanical properties, or temperature range are very superior. PC also has the characteristics of good insulation and dimensional stability. It can be used in many situations. Of course, the fire performance of PC is also good. The mold temperature of PC is also very mild and stable, and the size of the gate is also an important part. The larger the gate, the better. Huanke Precision is committed to the plastic injection processing transformation of PC performance, which fully reflects the professionalism of the dedicated injection molding factory.


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