A process for injection molding a contact lens PP case
By preheating the mold and using a bidirectional convection cooling pipe structure and heating the contact point of the ejector pin, the quality problem of the plastic part at the contact point between the mold and the ejector pin was solved, the surface smoothness and dimensional accuracy of the contact lens PP case were improved, and the toughness and consistency of the plastic part were enhanced.
Patent Information
- Application Number
- CN202610664302.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-05-14
- Publication Date
- 2026-07-10
AI Technical Summary
In the existing injection molding process for PP contact lens cases, quality problems in the plastic parts caused by the contact between the cold mold and the high-temperature melt include defects such as whitening and indentation at the ejector pin contact area.
The system employs a mold preheating and bidirectional convection cooling pipe structure, combined with slight heating at the ejector pin position. Mold preheating is achieved by setting up heat exchange chambers and preheating branch pipes inside the mold, and uniform cooling is achieved using nested inner and outer cooling pipes. The ejector pin contact position is heated before ejection to reduce ejector pin marks.
It improves the surface smoothness and dimensional accuracy of plastic parts, reduces ejector pin marks and uneven cooling, enhances the toughness and consistency of plastic parts, and avoids defects caused by uneven mold cooling.
Smart Images
Figure CN122353864A_ABST