a, owe note

failure analysis and elimination method:

(1) the improper control of technical conditions. It should be adjusted appropriately.

(2) The injection capacity of the injection molding machine is less than the weight of the plastic part. The injection molding machine with larger specifications should be replaced.

(3) The runner and gate sections are too small. They should be appropriately enlarged.

(4) The flow distance of molten material in the mold cavity is too long or there are thin-walled parts. Cold hole should be set.

(5) The mold exhaust is poor, and the residual air in the mold cavity leads to underinjection. The exhaust system of the mold should be improved.

(6) The flow performance of raw materials is too poor. The resin with better flow property should be changed.

(7) The temperature of the barrel is too low, the injection pressure is insufficient or the injection time of the feed is too short will also cause underinjection. The control amount of relevant process parameters should be improved accordingly.

2, flash flash

failure analysis and elimination method:

(1) insufficient clamping force. The injection molding machine with larger specifications should be replaced.

(2) The pin hole or guide pin of the mold is badly worn. It should be repaired by machining methods.

(3) There are foreign impurities on the closing surface of the mold. It should be removed.

(4) The molding die temperature or injection pressure is too high. It should be lowered appropriately.

3, surface porosity

failure analysis and elimination method:

(1) the thick wall runner and gate size of the mould is small easy to produce surface porosity. Should be appropriate to enlarge the size of the runner and gate.

(2) The wall of the plastic part is too thick. The wall thickness should be reduced as much as possible in the design.

(3) The molding temperature is too high or the injection pressure is too low will lead to porosity on the surface of the plastic part. Should be appropriate to reduce the molding temperature, increase the injection pressure.

4, flow mark

failure analysis and elimination method:

(1) melt and mold temperature is too low. The temperature of the barrel and the mold should be properly high.

(2) The injection speed is too slow. The injection speed should be appropriately accelerated.

(3) The nozzle aperture is too small. A nozzle with a larger aperture should be used instead.

(4) No cold hole is set in the mold. Cold hole should be added.

five, silver bar wire

failure analysis and elimination method:

(1) forming moisture and volatile matter content in the raw material is too high. The raw materials should be pre-dried.

(2) mold exhaust is poor. The exhaust hole should be increased to improve the exhaust performance of the mold.

(3) The nozzle is in poor contact with the mold. The position and geometric size of both should be adjusted.

(4) When the silver wire always appears in a certain part, it should be checked whether the surface of the corresponding mold cavity has surface scars. If there is a recurrence of surface scars, machining methods should be taken to remove the surface scars of the mold cavity.

(5) Silver streaks will occur when different varieties of resin are mixed. Mixing of dissimilar resins should be prevented.

6, welding scar

failure analysis and elimination method:

(1) melt and mold temperature is too low. The temperature of the barrel and the mold should be increased.

(2) Gate location setting is not reasonable. The gate position should be changed.

(3) The content of volatile substances in raw materials is too high or the mold exhaust is poor. The volatile substances in the raw materials should be removed and the exhaust system of the mold should be improved.

(4) The injection speed is too slow. It should be properly accelerated.

(5) No cold hole is set in the mold. Cold hole should be added.

(6) There are foreign impurities on the surface of the mold cavity. It should be cleaned.

(7) The gating system design is not reasonable. The mold filling performance of the pouring system should be improved to make the molten material flow smoothly in the mold cavity.

7, article black and scorched

failure analysis and elimination method:

(1) injection molding machine specification is too big. The injection molding machine with smaller specifications should be replaced.

(2) The flow performance of the resin is poor. An appropriate amount of external lubricant should be used.

(3) The injection pressure is too high. It should be lowered appropriately.

(4) mold exhaust is poor. The exhaust system of the mold should be improved, the Joe hole should be increased or the Mosaic structure should be adopted, and the clamping force should be appropriately reduced.

(5) Gate location setting is not reasonable. The gate position should be changed so that the molten material in the mold cavity flows evenly.

8, bubble

failure analysis and elimination method:

(1) the sprue and runner size is too small. It should be appropriately increased.

(2) Injection pressure is too low. It should be raised appropriately.

(3) The moisture content in the raw material is too high. The raw materials should be pre-dried.

(4) The wall thickness of the plastic part changes too much. The shape structure of the plastic parts should be reasonably designed to avoid sudden changes in wall thickness.

9, cracks and bleaching

failure analysis and elimination method:

(1) melt and mold temperature is too low. The temperature of the barrel and the mold should be increased.

(2) The structure design of the pouring system of the mold is unreasonable. The flow channel and gate structure of the mold should be improved so that the molten material does not produce turbulence when filling the mold.

(3) Cooling time is too short. The cooling time should be extended appropriately.

(4) The ejector device design of demoulding is unreasonable. It is best to use pneumatic ejection device.

(5) The injection speed and pressure are too high. It should be lowered appropriately.

10, bending deformation

failure analysis and elimination method:

(1) the mold temperature is too high or insufficient cooling. Should be appropriate to reduce the mold temperature or extend the cooling time, for slender plastic parts can be taken after the fixed cooling method.

(2) Uneven cooling. The cooling system of the mold should be improved to ensure uniform cooling of the plastic parts.

(3) Gate selection is not reasonable. Should be based on the specific situation, choose a reasonable gate form. Under normal circumstances, multi-point gate can be used.

(4) Mold core. Should be checked and corrected.

11, stripping bad

failure analysis and elimination method:

(1) injection speed and pressure is too high. Should be appropriate to reduce.

(2) The surface finish of the mold cavity is too poor. The surface finish should be improved by grinding and electroplating.

(3) Improper control of mold temperature and cooling conditions. When the plastic parts stick to the mold at the mold core, the mold temperature should be increased and the cooling time should be shortened; If the plastic parts stick to the mold at the surface of the cavity, the mold temperature should be reduced and the cooling time should be extended.

(4) The ejecting area of the ejecting mechanism is too small. The ejecting area should be increased.

12, contraction deformation

failure analysis and elimination method:

(1) the holding. The injection time of the feed should be appropriately extended.

(2) Insufficient injection pressure. It should be appropriately raised.

(3) Mold temperature is too high. It should be lowered appropriately.

(4) The gate cross-sectional area is too small. It should be appropriately enlarged.

(5) The processing temperature is too low. The barrel temperature should be appropriately raised.

13, vacuum hole

failure analysis and elimination method:

(1) the holding. The injection time of the feed should be appropriately extended.

(2) Mold temperature is too low, the barrel temperature is too high. The mold temperature should be properly increased and the barrel temperature should be reduced.

(3) Insufficient injection pressure. It should be appropriately raised.

(4) The flow performance of raw materials is too good. A resin with a lower melt index should be used.