Key considerations include traceability, biocompatibility, chemical resistance, sterilization capability, and supply reliability.
Selecting the proper plastic material for a medical application can be complex and challenging. For example, COC plastics are favored in diagnostics for their transparency and biocompatibility. Economical plastics such as PP, PE, and PS are suitable for disposable items, provided they meet necessary mechanical requirements. High-strength components such as insulin pens often use engineering thermoplastics such as POM, PA, or PPA. Plastics reinforced with fibers can replace metal, while impact-resistant materials like ABS, PC/ABS, polyamides, or PBT are often preferred for housing components.
Tips and Tricks for Processing
Achieving optimal injection molding results requires processing experience, skill, and finesse. Micro components require specialized equipment and transparent COC plastics require a nitrogen-rich environment to prevent yellowing and special demolding undercuts to prevent stress cracks. Products requiring bonding of different materials such as a plastic cartridge with sealing film, depend on proper material compatibility and a hot stamp thermobonding process with optimized bonding temperature, pressure, and time.
Special Multi-Component Injection Molding Expertise
RKT has extensive experience in multi-component injection molding, a process that combines different materials, often rigid and flexible resins, into a single component. This can streamline assembly, simplify logistics, and reduce production costs. Challenges of multi-component molding include effective product design, process temperature management for different plastics, and ensuring reliable adhesion despite varying shrink rates.
Compromises in Esthetics and Design Freedom
Plastics offer many advantages but also come with certain limitations. For example, their transparency does not quite match the optical clarity of glass and their designs must consider injection tool requirements, incorporating details like draft angles and radii for proper ejection. Considering and addressing these aspects early in the design process enhances the likelihood of successful, cost-effective high-volume production later.
Bottom Line: Plastic Injection Molding Is Efficient and High-Quality
