Adaptive Conformal Cooling of Injection Molds Using Additively Manufactured TPMS Structures.

Area of Science:

• Materials Science
• Manufacturing Engineering
• Polymer Science

Background:

• Traditional injection molding uses straight cooling channels, leading to inefficient cooling in curved molds.
• Conformal cooling channels offer improved uniformity but struggle with localized hot spots.
• Existing methods lack efficient cooling for specific heated regions in complex molds.

Purpose of the Study:

• To develop an adaptive conformal cooling method for localized-yet-uniform cooling in injection molds.
• To investigate the use of micro-cellular cooling structures, specifically triply periodic minimal surface (TPMS) structures, as an alternative to conventional channels.
• To optimize TPMS designs for enhanced cooling performance in additively manufactured mold cores.

Main Methods:

• Injection molding simulations were used to identify locally heated regions.
• Two biomimetic TPMS structures (Schwarz-diamond and gyroid) were designed and fabricated using digital light processing (DLP) additive manufacturing.
• Mold cores with optimized TPMS designs were manufactured using powder-bed fusion (PBF) metal additive manufacturing for experimental validation.

Main Results:

• The developed TPMS-based conformal cooling system achieved a cooling time of 15 seconds, meeting dimensional tolerances.
• This represents a 40% reduction in cooling time compared to conventional cooling methods (25 seconds).
• Various TPMS design parameters, including shape and base coordinates, were evaluated for their impact on cooling efficiency.

Conclusions:

• The adaptive conformal cooling method using TPMS structures significantly enhances cooling efficiency in injection molding.
• Additive manufacturing enables the fabrication of complex micro-cellular cooling structures for improved mold performance.
• This technology offers a viable solution for reducing cycle times and improving part quality in injection molding processes.