The formation mechanism and solutions of light guide strip mold shrinkage marks
Research on injection molding process of light guide mold
Sink marks in the injection molding process of light guide mold are local depressions on the surface of injection molded products caused by volume shrinkage. They are common in places with sudden changes in flesh thickness or wall thickness.
(1) Causes of shrinkage marks in optic light guide mold
  Reasons for product structure: unreasonable product design, excessive wall thickness or sudden and uneven wall thickness, resulting in uneven product shrinkage.
Material problems: The shrinkage rate of the material is too large or the flow performance is too poor, as well as insufficient lubricant or wet raw materials, which will cause
Causes depressions and shrinkage marks on the surface of plastic parts.
rear light guide strip mold design impact: the cross-section of the runner and gate of the mold is too small, the position of the feed port is unreasonable, and the mold exhaust is poor.
Mold filling resistance is too large, which affects material supply, feeding and cooling. Mold wear causes pressure relief, which will lead to concavity on the surface of the plastic part.
Sinks and shrinkage marks.
light guide strip mold injection molding machine reasons: the nozzle hole is too large, which reduces the injection force and makes filling the mold difficult; the check ring, screw or plunger are seriously worn,
Injection pressure cannot be transmitted to the cavity.
light guide strip mould molding process reasons: injection pressure or holding pressure is too low; injection time is too short or holding time is too short, the gate is not
During curing, the holding pressure ends; when the temperature is too high during demoulding, the plastic part is not cooled enough, and the temperature at the insert is too low, it will cause the plastic part to
Dimples or orange peel-like slight unevenness appear on the surface.

(2) Solutions to common sink marks in light guide strip mold
Improve product design so that the wall thickness of the product should be as uniform as possible; try to use materials with small shrinkage and low viscosity, as needed.
An appropriate amount of lubricant can be added to improve the fluidity of the melt; improve the gate design, appropriately expand the gate and runner cross-section, and
Try to set the location at or near the problem area; improve the design of the mold exhaust system; correctly control the holding pressure and
Holding time to compensate for shrinkage, appropriately extend the cooling time of plastic parts in the mold, and appropriately reduce melt temperature and mold temperature