The structural design of medical molds adheres to the principle of "minimalism," eliminating crevices and corners where contaminants could accumulate.
1. Dead-Zone-Free Runner Design
Hot runner systems are the primary choice: Unlike traditional cold runners, which carry a risk of residual solidified material, hot runner systems utilize precise temperature control (accuracy of ±1°C) to keep the plastic in a molten state, preventing the formation of "stagnant material" within the runner. For instance, a medical three-way connector mold using a hot runner and valve gate leaves ≤0.01g of residual melt after the gate closes, requiring only a surface wipe for cleaning.
Mirror-polished runner walls: With a surface roughness of Ra ≤0.05μm (near-mirror finish), flow resistance for the molten plastic is reduced by 30%, and residual melt is ejected along with the main runner, eliminating the risk of material adhesion.
2. "Hygienic" Design for Cavities and Ejection Mechanisms
Preference for integral cavities: This minimizes seams; for example, medical Petri dish molds are milled from a single block of steel, avoiding the bacterial accumulation associated with the crevices found in traditional assembled (insert-based) structures. Tests show that integral molds result in 92% less microbial growth compared to assembled molds.
Concealed ejector pin layout: Ejector pin holes feature a "tapered fit" (5°–8° taper) with a clearance of <0.005mm between the pin and the hole, preventing melt seepage and flash formation. Additionally, the ejector pins are hard-chrome plated (20μm thickness) for wear resistance and ease of cleaning.
3. Detachable Modular Design
For complex structures (such as molds for medicine bottle caps with spiral grooves), a "modular quick-release" design is employed:
Components such as cores and sliders can be disassembled within 10 minutes;
When paired with an ultrasonic cleaner (40kHz frequency), deep cleaning of crevices is achieved, increasing cleaning efficiency fivefold compared to traditional manual wiping.