The weld lines in Plastic Injection Molding refer to the surface defect caused by the two streams being welded together. Causes: If there are holes, inserts, or multi-gate injection molding methods in the fabricated parts or the wall thickness of the parts is uneven, weld lines may be generated. Remedies: Material: Increase the fluidity of …
Sink Marks in Plastic Injection Molding is a phenomenon in which the surface of the part is concave at the wall thickness. Causes: (1) Injection pressure or holding pressure is too low (2) The holding time or cooling time is too short (3) Melt temperature or mold temperature is too high (4) Improper design of …
Streaks in Injection Molding are those in which water, air, or char is distributed in the direction of flow along the surface of the part. Causes: (1) The moisture content in the raw materials is too high (2) Air is trapped in the raw material (3) Polymer degradation: the material is contaminated, barrel temperature is …
Flow lines are molding defects that are wavy on the surface of the product known as a kind of frog jump caused by the slow flow of the melt. Causes: (1)Mold temperature and the material temperature is too low (2) Injection speed and pressure are too slow (3) The size of the flow channel and …
A spray trace is caused by the melt flowing too fast in plastic injection molding, generally serpentine. Causes: (1) The gate size is too small, and it is facing the product surface with a large cross-sectional area (2) Filling speed is too fast Remedies: Mold design: (1) Increase the gate size (2) Change the side …
It refers to the surface of the part that can be peeled off layer by layer. Causes: (1) Mixing other incompatible polymers (2) Excessive release agent used during molding (3) resin temperature is inconsistent (4) Excessive moisture (5) The gate and the flow path have sharp angles Remedies: Material: Avoid incompatible impurities or contaminated recycled …
It means that excess plastic is present on the mold parting or ejector part. Causes: (1) Insufficient clamping force (2) The mold has defects (3) The molding conditions are unreasonable (4) Improper design of the exhaust system Remedies: Mold design: (1) Reasonably design the mold to ensure that the mold can be closed when the …
The burn marks in plastic injection molding are that the gas in the cavity cannot be removed in time, resulting in blackening at the end of the flow. Causes: (1) The air in the cavity cannot be removed in time. (2) Material degradation: overhigh melt temperature; overcast screw speed; improper design of the runner system …
Brittleness is that the plastic part is easily cracked or broken in some place Causes: (1) Dry conditions are not suitable; use excessive recycled materials (2) Injection temperature setting is wrong (3) The gate and runner system settings are not appropriate (4) The melting mark strength is not high Remedies: Material: (1) Set appropriate drying …
Air traps are where air is trapped in the cavity to create bubbles in the part during plastic injection molding. Causes: It is caused by the air being unable to escape from the parting surface, the ram, or the vent when the two melt fronts meet. Remedies: Structural design: Reduce thickness inconsistency and try to …
