Causes and countermeasures of injection molding failures of large thin-walled parts

Undernote
(1) Melt temperature is too low. The temperature of the barrel and nozzle should be properly raised.
(2) The nozzle hole is blocked. It should be removed.
(3) The injection pressure is too low. It should be properly improved.
(4) The injection speed is too slow. It should be accelerated appropriately.
(5) The injection and pressure holding time is too short. It should be extended appropriately.
(6) The material supply is insufficient. The material supply should be increased.
(7) The screw back pressure is low. It should be properly improved.
(8) Improper gate setting. The number of gates and the sectional area of gates shall be appropriately increased.
(9) The mold exhaust is poor. Mold exhaust should be increased.
(10) Die strength is insufficient. The rigidity of the mold should be improved as much as possible.
(11) The mold temperature is too low. It should be properly improved.
Vacuum hole
(1) Poor drying of raw materials. It shall be further pre-dried.
(2) The injection pressure is too high. It should be properly lowered.
(3) The injection speed is too fast. It should be slowed down appropriately.
(4) The mold exhaust is poor. Mold exhaust should be increased.
(5) The barrel temperature is too high. It should be properly lowered.
(6) The mold temperature is low. It should be properly improved.
(7) The screw back pressure is too low. It should be properly improved.
(8) The raw material is mixed with foreign matters. The raw materials shall be removed or replaced.
(9) Screw speed is too fast. It should be appropriately reduced.
Sprue shrinkage
(1) The material supply is insufficient. The material supply should be increased.
(2) The injection pressure is too low. It should be properly improved.
(3) The barrel temperature is too high. It should be properly lowered.
(4) The mold temperature is too low. It should be properly improved.
(5) The injection speed is too fast. It should be slowed down appropriately.
(6) The injection holding time is too short. It shall be appropriately shortened and extended.
Weld mark
(1) Melt temperature is too low. The barrel temperature should be properly raised.
(2) The injection pressure is too low. It should be properly improved.
(3) The injection speed is too slow. It should be accelerated appropriately.
(4) The material supply is insufficient. The material supply should be increased.
(5) Poor drying of raw materials. It shall be further pre-dried.
(6) The injection and pressure holding time is too short. It should be extended appropriately.
(7) The mold exhaust is poor. Mold exhaust should be increased.
(8) Improper gate setting. The number of gates and the sectional area of gates shall be appropriately increased.
Material flow mark
(1) The injection speed is too slow or too fast. It should be adjusted appropriately.
(2) Poor drying of raw materials. It shall be further pre-dried.
(3) The barrel temperature is too low. It should be properly improved.
(4) Improper gate setting. The number of gates and the sectional area of gates shall be appropriately increased.
(5) The screw back pressure is insufficient. It should be properly improved.
(6) The mold exhaust is poor. Mold exhaust should be increased.
(7) The raw material is mixed with foreign matters. It should be cleared.
Silver filigree
(1) Melt temperature is too high. It should be properly lowered.
(2) The mold temperature is too low. It should be properly improved.
(3) The raw material is mixed with foreign matters. It should be cleared.
(4) Poor drying of raw materials. It shall be further pre-dried.
(5) The mold temperature is too low. It should be properly improved.
(6) The injection speed is too fast. It should be slowed down appropriately.
Surface discoloration
(1) The barrel temperature is too high. It should be properly lowered.
(2) The injection speed is too fast. It should be slowed down appropriately.
(3) Screw back pressure is too high. It should be properly lowered.
(4) The mold exhaust is poor. Mold exhaust should be increased.
(5) Screw speed is too fast. It should be appropriately reduced.
Shrink impression
(1) The injection pressure is too low. It should be properly improved.
(2) The injection speed is too slow. It should be accelerated appropriately.
(3) The barrel temperature is too high. It should be properly lowered.
(4) The material supply is insufficient. The material supply should be increased.
(5) Improper gate setting. The number of gates and the sectional area of gates shall be appropriately increased.
(6) The mold temperature is too low. It should be properly improved.
(7) The injection and pressure holding time is too short. It should be extended appropriately.
(8) The nozzle hole is blocked. It should be removed.
Peeling and delamination
(1) The injection pressure is too high. It should be properly lowered.
(2) The barrel temperature is too high. The barrel temperature shall be properly reduced.
(3) The injection speed is too fast. It should be slowed down appropriately.
(4) The mold temperature is too high. It should be properly lowered.
(5) Uneven or insufficient cooling. The cooling time shall be appropriately extended or the products shall be placed in the mould for molding and cooling.
(6) Screw speed is too fast. It should be appropriately reduced.
(7) Too much release agent. It should be appropriately reduced.
(8) The nozzle hole is blocked. It should be removed.
(9) The raw material is mixed with foreign matters. It shall be thoroughly removed.
Warpage deformation
(1) Improper gate setting. The number of gates and the sectional area of gates shall be appropriately increased.
(2) Uneven or insufficient cooling. The cooling time shall be appropriately extended or the products shall be placed in the mould for molding and cooling.
(3) The injection pressure is too high. It should be properly lowered.
(4) The injection speed is too fast. It should be slowed down appropriately.
(5) The mold temperature is too high. It should be properly lowered.
(6) Melt temperature is too high. The barrel temperature shall be properly reduced.
(7) The mold exhaust is poor. Mold exhaust should be increased.
(8) Screw back pressure is too high. It should be properly lowered.
Unstable size
(1) Melt temperature is too high. The barrel temperature shall be properly reduced. However, it should be noted that if the melt temperature is too low, it will also cause dimensional instability.
(2) The injection pressure is too low. It should be properly improved.
(3) The screw back pressure is too low. It should be properly improved.
(4) The injection and pressure holding time is too short. It should be extended appropriately.
(5) Poor drying of raw materials. It shall be further pre-dried.
(6) Improper mold temperature control. If the mold temperature is too high or too low, it will cause dimensional instability, and should be adjusted appropriately.
Die Adhesion
(1) The barrel temperature is too high. It should be properly lowered.
(2) Improper material supply. The material supply shall be adjusted reasonably.
(3) The injection pressure is too high. It should be properly lowered.
(4) The injection speed is too fast. It should be slowed down appropriately.
(5) The injection and pressure holding time is too long. It should be shortened appropriately.
(6) Insufficient cooling. The cooling time should be appropriately extended.