Injection mold
1. If the mold cavity is poorly processed, such as scars, micro-holes, abrasion, roughness, etc., it will inevitably reflect on the plastic parts and make the plastic parts poorly shiny. For this, the mold must be carefully processed to make the cavity surface more Small roughness, chrome plating can be polished if necessary.
2. If there are oil stains, water stains on the surface of the cavity, or too much release agent, the surface of the plastic parts will be dark and dull. For this, the oil stains and water stains should be removed in time, and the release agent should be used in a limited amount.
3. If the demoulding angle of the plastic part is too small, it will be difficult to demould, or the force applied during demolding is too large, so that the surface of the plastic part has the best gloss. For this, the demoulding angle should be increased.
4. If the mold exhaust is poor, too much gas will stay in the mold, which will also cause poor gloss. For this, check and correct the mold exhaust system.
5. If the cross-sectional area of the gate or runner is too small or changes suddenly, the shear force will be too large when the melt flows in it, and it will flow in turbulent dynamics, resulting in poor gloss. For this, the gate and runner should be appropriately enlarged Cross-sectional area.
Two, injection molding process
1. If the injection speed is too low, the surface of the plastic part is not dense and the gloss is poor. For this, the injection speed can be appropriately increased.
2. For thick-walled plastic parts, if the cooling is insufficient, the surface will be hairy and the gloss will be dark. For this, the cooling system should be improved.
3. If the holding pressure is insufficient and the holding time is too short, the density of the plastic parts is insufficient and the gloss is poor. For this, the holding pressure and holding time should be increased.
5. If the melt temperature is too low, the fluidity will be poor and it is easy to cause poor gloss. For this, the melt temperature should be appropriately increased.
6. For plastic parts made of crystalline resin, such as PE, PP, POM, etc., uneven cooling will cause poor gloss. For this, the cooling system should be improved to make it evenly cooled.
7. If the injection speed is too high and the cross-sectional area of the gate is too small, the pouring product will be dark and poor in gloss. For this, the injection speed can be appropriately reduced and the cross-sectional area of the gate can be increased.
