(Polyethylene)
Specific gravity: 0.94-0.96 g/cm3
Mold shrinkage: 1.5-3.6%
Molding temperature: 140-220℃
Material performance
Corrosion resistance, excellent electrical insulation (especially high-frequency insulation), can be chlorinated, modified by irradiation, and can be reinforced with glass fiber. Low pressure polyethylene has a melting point, rigidity, hardness and strength, low water absorption, and good The electrical properties and radiation resistance of high pressure polyethylene; the flexibility, elongation, impact strength and permeability of high pressure polyethylene are good; UHMWPE has high impact strength, fatigue resistance and wear resistance. Low pressure polyethylene is suitable for making corrosion resistance Parts and insulation parts; high-pressure polyethylene is suitable for making films, etc.; ultra-high molecular weight polyethylene is suitable for making shock-absorbing, wear-resistant and transmission parts.
Forming performance
1. The crystalline material has low moisture absorption, does not need to be fully dried, and has excellent fluidity. The fluidity is sensitive to pressure. High pressure injection should be used when molding, the material temperature is uniform, the filling speed is fast, and the pressure is fully maintained. Direct gates are not suitable to prevent shrinkage Uneven, internal stress increases. Pay attention to choosing the gate position to prevent shrinkage and deformation.
2. The shrinkage range and shrinkage value are large, the directionality is obvious, and it is easy to deform and warp. The cooling speed should be slow, and the mold should be equipped with a cold material cavity and a cooling system.
3.The heating time should not be too long, otherwise it will decompose and burn.
4. When the soft plastic part has a shallow side groove, it can be forced to demould.
5. Melt rupture may occur, and it is not suitable to contact with organic solvents to prevent cracking.