The Formation Process Of Cavitation And It'S Solution For Thick Wall Parts Mould

The formation process of cavitation and its solution
Research on the injection molding process of the thick-walled transparent part of the car light guide strip mold
Cavitation is the defect that gas cannot be discharged from the mold cavity in time during the final filling process of injection molding, and remains in the inside or surface of the product. Or when the wall thickness of the product is large, the uneven volume shrinkage makes the outer surface cooler than the center part. of
Quickly, the center part produces vacuum bubbles formed by insufficient filling.
(1) Causes of cavitation
Reasons for product design: The ratio of thin to thick in product design is too large, resulting in unsmooth material flow.
Raw material problems: the raw materials are relatively moist or too much volatile matter; the melt will degrade and produce gas when heated at high temperature;
Material fluidity is poor or shrinkage does not meet the requirements, etc.
Mold design issues: poor mold venting conditions, too small vent holes, insufficient number or inappropriate location; no design
Set a reasonable thimble or insert to enhance exhaust.
The influence of injection molding process conditions: low injection pressure, insufficient holding pressure, and excessively fast injection speed will cause large shearing of molten plastic
It decomposes to produce decomposition gas; air is mixed into the barrel; the melt temperature or mold temperature is too low to reduce the melt fluidity.
(2) Solutions to cavitation
Select injection molding materials with shrinkage and fluidity that meet the requirements, and fully dry the materials; rationally adjust the structure of the injection molded parts
Design, try to make the wall thickness uniform, improve mold exhaust, increase cavity exhaust ability, adjust gate size or position;
High injection pressure and screw back pressure, appropriately extend the holding time, and reasonably control the injection speed.
The above is the injection technology process of thick-walled light guide strip mold, thick-walled transparent part auto lamp mold, and transparent thick-walled car light guide strip mold