Specific gravity:0.94-0.96g/cm3
Molding shrinkage:1.5-3.6%
Molding temperature:140-220℃
Material performance
Corrosion resistance, electrical insulation (especially high frequency insulation) excellent, can be chlorinated, irradiation modified, available glass fiber reinforced. Low pressure polyethylene has high melting point, rigidity, hardness and strength, low water absorption, good electrical properties and radiation resistance; high pressure polyethylene has good flexibility, elongation, impact strength and permeability; ultra-high molecular weight polyethylene has high impact strength, fatigue resistance and wear resistance.
Low pressure polyethylene is suitable for making corrosion resistant parts and insulating parts; high pressure polyethylene is suitable for making films, etc.; UHMWPE is suitable for making shock absorbing, wear resistant and transmission parts.
Molding performance
1、Crystalline material, small moisture absorption, do not need to fully dry, excellent fluidity, fluidity is sensitive to pressure. High-pressure injection is suitable for molding, uniform material temperature, fast filling speed and sufficient pressure-holding. It is not suitable to use direct gating to prevent uneven shrinkage and increase of internal stress. Pay attention to the choice of gate location to prevent shrinkage and deformation.
2、Shrinkage range and shrinkage value is large, the direction is obvious, easy to deformation and warpage. The cooling speed should be slow, and the mold should have cold cavities and cooling system.
3、Heating time should not be too long, otherwise decomposition will occur and burns.
4、When the soft plastic parts have shallow side grooves, the mold can be forced off.
5、Rupture of the melt may occur and should not be in contact with organic solvents to prevent cracking.
Specific gravity:1.18-1.20g/cm3
Molding shrinkage:0.5-0.8%
Molding temperature:230-320℃
Drying condition:110-120℃ 8 hours
Material performance
High impact strength, good dimensional stability, colorless and transparent, good coloring, good electrical insulation, corrosion resistance and abrasion resistance, but poor self-lubrication, stress cracking tendency, easy hydrolysis at high temperature, poor compatibility with other resins.
It is suitable for making small insulating and transparent parts of instruments and impact resistant parts.
Molding performance
1, amorphous material, good thermal stability, wide range of molding temperature, poor fluidity. Small moisture absorption, but sensitive to water, must be dried. Molding shrinkage is small, prone to melt cracking and stress concentration, so the molding conditions should be strictly controlled, and the plastic parts should be annealed.
2, high melting temperature, high viscosity, more than 200g plastic parts, it is appropriate to use the heating type extension nozzle.
3、Fast cooling speed, mold pouring system to coarse, short as the principle, should be set up cold material well, the gate should be taken large, mold should be heated.
4, the material temperature is too low will cause lack of material, plastic parts without luster, the material temperature is too high easy to overflow edge, plastic parts blistering. When the mold temperature is low, the shrinkage, elongation and impact strength are high, while the bending, compression and tensile strength are low. When the mold temperature exceeds 120 degrees, the plastic parts are slow to cool and easy to deform and stick to the mold.