Gas-assisted injection moulding: In certain medical device applications, gas-assist moulding can provide solutions that conventional injection moulding can’t. The process consists of injecting a pressurised gas into the mould cavity after the initial plastic injection, expelling the molten plastic and forming hollow areas within the final product. It is suited to the manufacturing of complex parts without visual blemishes, for instance, tube- or rod-shaped parts which typically include handles and foot pedals, as well as large, cover-shaped structural parts e.g. side panels and covers for medical devices.

Liquid silicone injection moulding: This produces pliable, durable parts in high volume, and is used in fabricating tubes and respiratory masks requiring high levels of hygiene and chemical resistance.

Japan’s Polyplastics says POM and PP can replace the likes of higher-cost PPS, which is typically used to channel coolant in internal combustion engines.

Perhaps intriguingly is the fact that 3D printing and injection moulding are not exclusive of one another. Injection moulding is frequently preceded by 3D printing, which assists with prototyping and even helps create moulds for the injection moulding process.

Thin wall moulding: A specialised form of conventional injection moulding that focuses on the mass production of ultra-thin (less than 1mm) and light plastic parts to make material cost savings. This is used to create portable medical devices enabling clinicians and patients to transport and operate them more easily - such as wearable devices, micro surgical tools, and invasive equipment like catheter ablation tools and endoscopes.

The indelible imprint of injection moulding in medical manufacturing underscores its pivotal role in delivering efficient, high-quality, and cost-effective solutions to the industry. As the medical field continues to evolve, the synergy between injection moulding and emerging technologies like 3D printing is poised to drive innovation further, ensuring the continual enhancement of patient care and medical advancements.

Luke Smoothy, founder and director, Get It Made, delves into why injection moulding still holds the sceptre in the medical industry and highlights the key benefits it brings.

An expansive range of materials are available with injection moulding, making it easier to produce medical equipment that adheres to the strict biosafety and chemical stability criteria of the medical sector. Techniques such as thin wall moulding and gas-assisted injection moulding enable the production of both practical and aesthetically appealing parts.

BEVs do not have engines as heat sources and, therefore, require an LLC temperature of 100°C or lower to cool the battery. This allows for the use of less heat-resistant materials for BEV-specific components.

The Polyplastics Group, a global supplier of engineering thermoplastics, has introduced an approach for using less heat-resistant plastics for battery electric vehicle (BEV) cooling components. Polyplastics sees strong potential for plastics such as polyacetal (POM) and polypropylene (PP) for the production of EV cooling components.

Internal combustion engine (ICE) automobiles use a long-life coolant (LLC) that is primarily made of ethylene glycol. The coolant in engines is typically maintained at a temperature of 70° to 100°C but can rise to 120°C or higher if the engine overheats. Therefore, metals or high-heat-resistant plastics like polyphenylene sulfide (PPS) are used in the cooling components and lines.

Stephen has been with PlasticsToday and its preceding publications Modern Plastics and Injection Molding since 1992, throughout this time based in the Asia Pacific region, including stints in Japan, Australia, and his current location Singapore. His current beat focuses on automotive. Stephen is an avid folding bicycle rider, often taking his bike on overseas business trips, and is a proud dachshund owner.

When the temperature of an LLC is 100°C or lower, general-purpose engineering plastics like POM or PP can be used instead of metals or high-performance engineering plastics. In the case of PP, Polyplastics sees potential for PP-LGF (long glass fiber) instead of short glass fiber to increase strength, dimensional accuracy, and overall performance. It also offers Duracon bG-POM made with biomass as an eco-friendly option.

Well-suited for products with straightforward shapes, injection moulding delivers unrivalled precision and finish quality. For medical applications such as moving machine parts or implantable devices, the procedure gives a vital smoother finish.

Since the need for devices and components in the medical sector is always increasing, injection moulding stands out for its effectiveness and capacity to handle large-scale orders. The method is best suited for high-volume production, making it the preferred method for mass-producing medical components. That said, even though 3D printing is hailed for having cheaper initial costs in small-scale production, its cost advantage diminishes as production volume rises.

As the automotive industry moves from traditional ICE vehicles to BEVs, OEMs and part manufacturers are re-imagining the types of materials that can meet the new thermal management needs. Polyplastics believes that less-heat-resistant plastics like POM and PP have significant potential in the manufacture of EV cooling components.

In the realm of medical device manufacturing, the tussle between traditional injection moulding and modern 3D printing technologies continues. However, injection moulding has held its ground firmly, especially when high-volume production, cost-effectiveness, and precision are all paramount.

Replacing highly heat-resistant plastics such as PPS with POM and PP not only reduces material costs but also helps reduce the carbon footprint of materials and energy consumption during molding.