1, Present problem: plastic is wavy.
Cause: due to the narrow gate or other parts, when the molten plastic pushes the solidified plastic part forward, the surface will produce ripples.
Solution: 1. Increase injection diameter 2. Increase injection nozzle and mold temperature 3. Increase barrel height 4. Speed up injection 5. Slow down injection 6. Change mold cooling water inlet to keep it away from Gate 7. Expand gate.
2, Present problem: the plastic part is in the shape of silver grain.
Cause: due to the moisture content of plastic, uneven mixing, air entrainment during injection, excessive additives or release agents.
Solution: 1. Strengthen the back pressure 2. Slow down the injection speed 3. Clean the barrel 4. Increase the mold temperature 5. Change the gate position 6. Expand the flow channel and gate 7. Dry the material 8. Install infrared light in the gate.
3, Problem: poor plastic interface.
Cause: because the plastic temperature is too low to melt, or because of insufficient gas discharge, more than two strands of shunt mix, resulting in hairline or bubble.
Solution: 1. Increase the material temperature 2. Increase the injection temperature 3. Increase the injection speed 4. Set a cold material pool outside the seam line 5. Set a vent 6. Change the gate position or gate 7. Do not use mold release agent 8. Switch to low viscosity raw materials that are easy to flow.
4, Present problem: the plastic part presents void.
Cause: the surface of the plastic contacts the low-temperature mold wall during the solidification of the melt, and the shrinkage is concentrated in the thick wall section, resulting in the cavity, or the cavity is made by air entrainment.
Solution: 1. Increase injection pressure (and secondary pressure) 2. Extend injection time 3. Reduce solidification temperature of barrel 4. Reduce die wall thickness to less than 6 mm, if necessary, set equal wall thickness assistant line, and remove excess wall thickness 5. Expand gate 6. Shorten flow channel 7. Adjust die temperature 8. Change gate position and eliminate air entrainment.
5, Problem: plastic parts are under noted or short of material.
Cause: due to the insufficient mechanical injection and plasticizing performance, poor material flow, too thin gate section, too thin mold wall or poor air release.
Solution: 1. Increase injection rate. If it is still insufficient, heavy machinery should be replaced. 2. Install leak proof injection valve type screw. 3. Increase injection pressure. 4. Increase solidification of barrel, injection nozzle and mold temperature. 5. Check whether the hot wire is broken. 6. Check whether the injection nozzle is blocked and increase circulation speed. 7. Improve the mold air release capacity. 8. Increase the gate section. 9. Increase the product wall thickness. 10. Add auxiliary lines and improve the material flow. 11. Select low viscosity raw materials. 1 2. Add lubricant.
6, Present problem: extrude plastic while closing die.
Cause: too high material temperature and injection pressure, or insufficient clamping force.
Solution: 1. Reduce injection pressure and curing temperature of cylinder 2. Shorten injection time 3. Reduce injection speed 4. Use high locking force machine 5. Transform the surface of the mold and clean the surface of the mold 6. Use low viscosity material.
7, Present problem: the surface of the plastic part is dented.
Cause: the surface of plastic parts is cooled when it is wrong, because of its surface dent.
Solution: 1. Increase the injection rate 2. Increase the internal pressure (secondary pressure) of the mold slot 3. Reduce the curing temperature of the cylinder 4. Increase the injection flow 5. Increase the injection rate 6. Extend the injection time 7. Make the mold temperature uniform 8. Change the gate position 9. Expand the gate 10. Shorten the mold channel.
8, Problem: the plastic part is distorted.
Cause: deformation and distortion of plastic parts caused by residual stress relaxation of injection molding.
Solution: 1. Reduce injection pressure 2. Reduce the curing temperature of the cylinder 3. Extend the cooling time 4. Adjust the wall thickness of the material part and the action of the demoulding lock 5. Add demoulding lock 6. Change the gate position 7. Adjust the mold temperature.
