Flash, also known as burr, is typically caused by the following reasons:
Poor closure of the parting line with gaps present.
Weak mold strength, resulting in local deformation of the mold cavity due to internal pressure during the molding process, creating gaps.
Poor balance of the mold, leading to tilting and deformation.
High injection pressure and insufficient clamping force.
Excessively high material and mold temperatures, coupled with excessively fast injection speed.
Solutions:
Increase the clamping force and adjust the precision of the mold closing surface to ensure a tight fit.
Adjust process parameters to minimize internal mold pressure as much as possible.
Repair the mold to ensure its balance.
Adjust the injection pressure and clamping force.
Replace with a material with appropriate fluidity and adjust to suitable material temperature, mold temperature, and injection speed.
