How to increase the brightness of injection products from process and mold
How to increase the brightness of injection products from process and mold
1. If the mold cavity is poorly processed, such as scars, micropores, wear, roughness and other deficiencies, it will inevitably react to the plastic parts, resulting in poor luster of the plastic parts. For this, it is necessary to carefully process the mold, so that the surface of the mold cavity has a small roughness, and if necessary, it can be polished and chrome plated.2. If there is oil stain or water stain on the surface of mold cavity, or too much mold release agent, the surface of plastic part will be dark and lusterless. For this, oil stain and water stain shall be removed in time, and mold release agent shall be used in limited quantity.
3. If the demoulding slope of the plastic part is too small, it is difficult to demould, or the force is too large during demoulding, so that the surface luster of the plastic part is better, the demoulding slope shall be increased.
4. If the mold exhaust is poor, too much gas stays in the model, which also leads to poor gloss. Therefore, check and correct the mold exhaust system.
5. if the cross-sectional area of the gate or runner is too small or suddenly changed, the melt will flow in a turbulent dynamic state under the action of shear force, resulting in poor luster. Therefore, the cross-sectional area of the gate and runner should be appropriately increased.
2、 Injection molding process
1. If the injection speed is too small, the surface of the plastic part is not dense and shows poor luster, the injection speed can be increased appropriately.
2. For thick wall plastic parts, if the cooling is not sufficient, the surface will be hairy and the luster will be dark. Therefore, the cooling system should be improved.
3. If the holding pressure is insufficient and the holding time is short, the density of the plastic part is not enough and the luster is not good, the holding pressure and holding time should be increased.
5. If the melt temperature is too low, the fluidity is poor and the gloss is easy to be poor. Therefore, the melt temperature should be properly increased.
6. For the plastic parts made of crystalline resin, such as PE, PP, POM, etc., if the cooling is not uniform, the gloss will be poor. Therefore, the cooling system should be improved to make it cool evenly.
7. If the injection speed is too high and the cross-sectional area of the gate is too small, the area near the gate will be dark and glossy. Therefore, the injection speed can be appropriately reduced and the cross-sectional area of the gate increased.
