Medical plastic mold production must meet stringent requirements for high precision, high cleanliness, biocompatibility, and long-term stability, spanning material selection, mold design, manufacturing processes, production environment, quality inspection, and regulatory compliance. Below are the specific production requirements:

1. Material Selection: Balancing Biocompatibility and Performance

1.1 Mold Materials

• Must exhibit high corrosion resistance, excellent polishing performance, and robust mechanical strength. Common materials include:
• S136 Stainless Steel: After solution treatment (1050°C) and aging treatment (450°C), it achieves a hardness of HRC 45-48, complies with ISO 10993-1 biocompatibility standards, and resists rust after 20 cycles of 121°C sterilization.
• 718H Pre-hardened Steel: With a hardness of HRC 32-36, it offers superior wear resistance (wear ≤0.002 mm per 100,000 injection cycles) and is suitable for non-direct-contact mold components (e.g., reagent bottle molds).

1.2 Plastic Resins

• Prioritize medical-grade materials compliant with ISO 10993, such as:
• Polycarbonate (PC): Used for syringe barrels and IV connector molds, requiring 12 biocompatibility tests (e.g., cytotoxicity, sensitization, pyrogenicity).
• Polyphenylsulfone (PPSU): For surgical instrument handles and endoscope housings, with a narrow molecular weight distribution (<1.8) to ensure batch consistency.
• Polyetheretherketone (PEEK): For orthopedic implant molds, often reinforced with carbon fiber to enhance mechanical properties (tensile strength increased by 50%-80%).

2. Mold Design: Precision and Functional Synergy

2.1 High-Precision Tolerances

• Dimensional Accuracy: Mold manufacturing tolerances must be controlled within ±0.005 mm, with critical dimensions (e.g., syringe barrel inner diameter) held to ±0.02 mm.
• Surface Finish: Mold cavities require mirror polishing to Ra ≤0.2 μm, with some implant molds receiving hard chrome or DLC coatings for wear resistance.

2.2 Functional Optimization

• Gate and Runner Systems: Hot runner systems minimize weld lines, while cold runners are shortened (<3 mm diameter for soft PVC) to prevent material degradation.
• Ejection Mechanisms: For undercut features (e.g., artificial joint molds), angled lifters (3°–6° angle) ensure precise ejection without surface damage.
• Cooling Systems: Conformal cooling channels reduce mold surface temperature variation to ±1°C, minimizing thermal stress-induced distortion.