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.
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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.
Efficiency and scalability
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.
Precision and finish quality
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.
Versatility in material and design
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.
Real-world applications
Below are examples of various types of injection moulding which are employed to create a myriad of medical devices:
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.
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.
Bridging with 3D printing
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.
The future role of injection moulding
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.