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 too high; insufficient injection volume
Remedies:
Mold design:
Check if the exhaust position is sufficient Process:
(1) Choose the right injection molding machine and mold
(2) When switching materials, clean the old materials completely from the barrel
(3) Improve the exhaust system
(4)Reduce melt temperature, injection pressure or injection speed
