The Impact of Engineering Plastics on the Medical Field

1. Major Engineering Plastics and Their Applications in the Medical Field

1.1 PEEK (Polyetheretherketone)

PEEK maintains excellent mechanical strength and chemical resistance at high temperatures up to 260°C, making it widely used in spinal fixation devices, artificial joints, and dental restorations. Its low moisture absorption and resistance to steam sterilization ensure long-term stability and biocompatibility of implantable components produced through medical injection molding.

1.2 PPSU (Polyphenylsulfone)

PPSU exhibits outstanding chemical stability and high-temperature sterilization resistance, commonly used in manufacturing surgical instrument handles, catheter connectors, and respiratory mask components. Utilizing medical device molding processes enables consistent molding of intricate designs and withstands multiple sterilization cycles.

1.3 POM (Polyoxymethylene)

POM offers high rigidity, low friction, and excellent wear resistance, suitable for producing micro gears, pulleys, valve cores, and other precision transmission components. Its low viscosity facilitates filling of small cavities, and when combined with high precision plastic injection molding technology, it achieves dimensional tolerances within ±0.05 mm.

1.4 PC (Polycarbonate)

PC is naturally transparent, possesses high impact strength, and resists various sterilization methods (EO, gamma radiation, steam). It is commonly used in infusion pump housings, display windows, and optical lens components. Through medical injection molding, high-gloss transparent parts can be obtained in a single molding process, eliminating the need for secondary polishing.

2. Material Properties and Product Advantages of Engineering Plastics

• High-Temperature Resistance: PEEK and PPSU have heat resistance temperatures up to 260°C and 190°C, respectively, ensuring device performance remains unaffected after steam, chemical, or radiation sterilization.

• Chemical and Biocompatibility: These engineering plastics are non-toxic and non-irritating to human tissues, complying with ISO 10993 and other biocompatibility standards, making them suitable for long-term implantation or contact with blood environments.

• Mechanical Strength and Dimensional Stability: POM's low moisture absorption and PC's high rigidity ensure geometric stability of precision parts during humid and thermal cycles, reducing subsequent assembly errors.

• High Precision and Consistency: Utilizing high precision plastic injection molding technology with precise temperature control and screw design maintains consistent dimensions and performance of each part in mass production.

3. Key Considerations in plastic mold design and Molding Processes

1. Runner and Gate Design: Due to the high melt viscosity of engineering plastics, it is recommended to use rectangular or side gates, and appropriately widen runners to reduce pressure loss and shear heating.

2. Mold Material and Heat Treatment: Select high wear-resistant and high-strength steels like H13, and perform vacuum nitriding or PVD coating treatments to extend mold life and enhance cavity surface finish.

3. Cooling System Layout: Given the low thermal conductivity, design denser cooling channels or use high thermal conductivity metal inserts to ensure uniform cavity temperature, reducing warpage and internal stress.

4. Ventilation and Ejection Structures: For micro features or deep cavities, arrange micro venting grooves in the mold and adopt sliders or side ejection structures to prevent surface defects and product cracking.

4. Conclusion and Call to Action

The extensive application of engineering plastics in medical devices relies not only on their superior material properties but also on advanced medical injection molding, medical device molding, and high precision plastic injection molding technologies, as well as appropriate plastic mold design. By optimizing material selection and process schemes, medical manufacturers can obtain highly reliable and high-performance medical components that meet stringent regulatory and clinical requirements. For more information on solutions or customized services, please contact JSJM immediately to jointly promote innovation and development in medical devices!