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paper ripped over plastic medicakl waste with the label 'single use only'

Paper injection moulding and medical devices: a plastic alternative?

Published: January 2024
Updated: March 2024

Jimmy Mower

Jimmy Mower, Design Consultant

The damaging environmental impact of plastic waste has prompted our industry to seek sustainable alternatives.

Medical device designers face the challenge of finding the right balance between creating robust and reliable components and delivering eco-friendly designs. Choosing alternative materials and processes can reduce environmental impact while ensuring the necessary functionality and performance.

This is why Shore has been working with industry on the development of products that utilise more sustainable materials and technologies.

What technologies are available?

One good example is paper injection moulding (PIM), a technology developed to be an alternative to traditional injection moulding. It involves the injection moulding of paper (pulp) instead of plastic, creating 3-dimensional structural parts.

The material is made from 100% renewable sources, made from pulp, starch, and water. Its process allows great design freedom, enabling the production of complicated geometries, thin walls, undercuts, and precise thicknesses.

close up of paper injection moulding

Paper injection moulding. Photo credit: Nissha

Advantages of paper injection moulding

Firstly, these materials are environmentally friendly and fully biodegradable, naturally dissolving within approximately six months. They are non-toxic, ensuring safety during disposal.

The components offer the advantage of being lightweight and exhibit high heat resistance, making them suitable for applications where elevated temperatures may be a concern.

However, the benefits of pulp extend beyond its eco-friendly properties. The manufacturing process is also cost-effective and energy-efficient, making it an attractive option for various industries, including medical devices. Pulp mouldings can also be used with glucose-based adhesive labelling which is also recyclable, further enhancing their sustainability credentials.

With a reduced carbon footprint and the potential for multi-functionality, it demonstrates great promise as a sustainable alternative to traditional plastics in medical devices and other industries.

Use in medical devices

Within the disposable goods sector, moulded pulp products have witnessed widespread adoption owing to their cost-efficiency, biodegradable properties, and disposability.

Notably, the clinical healthcare product segment, encompassing items such as urine bottles, bedpans, kidney dishes, and bowls, represents a burgeoning application area for these materials.  

The COVID-19 pandemic also highlighted the issue of single-use plastic waste, particularly in the context of plastic-based tests, which have become a significant source of environmental concern.

COVID 19 lateral flow test plastic

COVID-19 highlighted single-use plastic waste

In the pharmaceutical industry, especially in high-volume single-use medical devices, there is scope to explore renewable materials and introduce a carbon-neutral alternative.

Nissha, a key player in the development of PIM technology, is making remarkable progress in this area. The company recently showcased its expertise at Pharmapack, unveiling autoinjector components moulded from pulp.

They have developed a concept prototype for a self-injection pen cap and it not only grabbed attention on the exhibition floor but also earned Nissha the Packaging Innovation Award at the show’s award ceremony. The concept is now undergoing further process optimisation to achieve even better surface and mechanical quality.

Paper injection moulded component. Self-injection pen cap.

Paper injection moulded self-injection pen cap. Photo credit: Nissha and CPHI

Consumer and patient preference

The growing environmental consciousness among consumers and patients is a significant influence in the industry. Through human factor studies we’ve observed a clear preference for sustainable options, along with appreciation for manufacturers’ efforts to adopt more environmentally considerate designs.

This shift in consumer preference not only aligns with global environmental goals but also enhances the overall perception of medical devices. Many patients are more inclined to embrace technologies when they perceive them both as beneficial for their health and environmentally friendly.

Recycling in manufacturing

Pulp and paper materials offer a versatile solution for advancing sustainability in manufacturing. Firstly, they significantly contribute to circular design principles. Manufacturers can benefit from ease of disassembly compared to plastic, as it simplifies the process of breaking down products at the end of their life cycle.

Additionally, paper-based materials are simpler to “rip open,” allowing manufacturers to remove the outer housing and retrieve internal components for re-use or recycling, thereby supporting the use of recycled materials in manufacturing.

Challenges to overcome

While pulp boasts numerous advantages, the material has a lower perceived quality compared to plastic, so the industrial design challenge is to make a device which looks high quality, robust and disposable at the same time.

Depending on the design, components may exhibit weakness under high humidity, affecting their performance in specific environments. For example, living hinges have limited durability, with a lifespan restricted to one or two folds. Additionally, certain intricate details components may necessitate post-moulding trimming, adding complexity to the manufacturing process.

However, given its prevalence in high-end consumer goods packaging, users are already familiar with these materials. This familiarity helps break down the initial intimidation associated with handling sterile, precise medical instruments.

Collaborative efforts between material scientists, designers, and manufacturers play a vital role in addressing these challenges and increasing the potential of paper & pulp as an eco-friendly and innovative alternative to traditional plastics.

What's next for plastic alternatives?

These new processes and materials are a potential game-changer, offering the possibility of replacing traditional plastics with fully biodegradable materials that naturally dissolve. However, it’s important to recognise that there will be scenarios where they may never fully replace existing materials. One such example is medical syringes where the requirements for sterility and durability make it challenging to replace plastics entirely.

Nonetheless, the reduced environmental impact, combined with comparable geometry and strength to traditional plastics, makes them a promising path for medical device manufacturers seeking greener alternatives.

As technology continues to advance, collaborative efforts between material scientists, engineers, and medical professionals will be instrumental in overcoming challenges and expanding applications in medical devices.

If you’re keen to explore alternative sustainable materials for your medical designs, then contact us and we’d love to discuss.

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