Can you achieve truly sustainable moulded medical devices?

Sustainability in the life cycle of medical grade plastics

There are many sustainability considerations when it comes to the life cycle of moulded materials such as plastics, including where and how they are sourced, manufactured, reused and recycled, as well as end-of-life considerations.

The following are some key sustainability considerations in the life cycle of plastics, from inception to disposal.

Raw material use

One of the most common considerations around sustainability is that we are running out of raw fossil-based materials. In the context of moulded materials for sustainable moulded medical device development, this means that to maintain supply we need to develop polymers created from an inexhaustible resource.

It’s amazing to see many resin manufacturers moving away from fossil minerals and oils and developing medical products from bio-produced raw materials, such as by-products of the food, paper and timber industries. While moving away from fossil-based oils and fillers may be the ideal solution for longevity of supply, as these raw materials guarantee the ability to grow for decades or centuries to come, this on its own won’t stop the mountains of waste growing. That being said, bio-produced raw materials should still be considered in conjunction with planned reuse or recycling.

Reuse and recycle

Without any shadow of doubt, the climate crisis is the primary cause for the shift in impetus from both the consumer and manufacturer to look for greener alternatives. It’s unsurprising then that this is where the focus of most attention lies. Using less should be the first consideration, and then reusing, recycling and reprocessing the materials we are surrounded by has to be the next key priority. In this space, the range of ‘recycling’ by type and degree is extensive.

Planned material degradation

Compostable, bio-degradable, soluble materials and specialised composting facilities have existed for many years and are still breaking new ground in development. These materials can break down into their chemical elements naturally over time, but only in the specific conditions in industrial composters. We have already seen these materials widely applied in consumer applications such as food waste bags or teabags. However, in the medical sector, bio-degradable product properties are highly likely to be mutually exclusive to their essential requirements. Many products are expected to suffer no degradation during their shelf life of at least two years and thus need to withstand varying temperatures, humidity and environmental conditions without affecting their mechanical integrity. This can prove challenging in your device development, when attempting to use materials designed to break down over time.

Selecting the right plastic manufacturer for your medical device

With so many interpretations of what constitutes a sustainable product, how do you select the right manufacturing partner to align with your sustainability needs? This is where regulatory standards come into play.

ISCC

The International Sustainability and Carbon Certification (ISCC) board certifies companies who claim they meet sustainability goals at a product level with regards to bio-based and recycled materials, as well as traceability throughout their supply chain. It also verifies that manufacturers meet social and environmental standards.

A product with ISCC Plus ® certification verifies that the manufacturer has demonstrated:

• Substitution of fossil raw materials
• Protection of land with high biodiversity / carbon stock
• Environmentally friendly production to protect soil, water and air quality
• Reduction of greenhouse gas emissions
• Traceability of supply chains
• Respect for human, labour and land rights
• Compliance with laws and international treaties

What are the qualifying attributes for ISCC compliance?

In order to achieve ISCC compliance, manufacturers must follow a number of processes, from ensuring renewable sources to enabling recycling.

Sustainable medical device manufacture - renewable attributed polymers

Renewable attributed polymers utilise bio-feedstock, which are raw materials produced from non-fossil sources such as the oils, fibres and fillers which are a by-product of other vegetable-based industries. First-generation bio-sources are harvested as a by-product of food crops, while second-generation are by-products of wood and non-edible crops. Finally, third-generation are from microalgae and other microorganisms, such as cyanobacteria.

Producing plastics as a by-product is nothing new. Polymers have historically been a by-product of the fossil oil industry, so it makes perfect sense to use the raw materials and oils that are not required for food production, formally waste products, to create plastics.

Land use is another key consideration for producing the materials needed for bio-based polymers. No sustainable products can be allowed to negatively impact the food chain, meaning any land used for purely bio-mass farming must be negligible. This is to avoid having any effect on the land, natural resources, or energy used for growing food.

Currently, the area of usable farmland taken up for bio-mass specific crops worldwide is thought to be less than 0.02%. Agricultural waste is therefore used to avoid contributing to land use pressures, as the use of bio-feedstock scales up.

Some polymers lend themselves well to bio-feedstock due to the chemistry of the materials. For example, there are manufacturers claiming 100% bio-feedstock for their high-performing engineering polymers, manufactured from 100% green energy – a high accolade indeed. But while this is an important advance, without a carefully planned route for reuse or recycling, this alone is not the sole answer to sustainability.

Post Industrial Recycled (PIR)

PIR feedstock is the reused material from manufacturing. This includes material such as moulding sprues and runners, short-shots, defective parts and purged material from the start and end of moulding runs. Unfortunately, by the nature of manufacturing economics, these materials are not in plentiful supply and therefore PIR doesn’t feature highly in many grades of recycled content materials. Generally, it gets ground up and reused in the same place it was produced. It’s also both used in and sourced from inter/intra-industrial packing, such as component trays and other manufacturing in-process parts, which cannot be reused or have a limited lifespan.

‘Downcycling’ is a term used for plastics that have been deemed not recyclable for the same purpose and so are downgraded from their current form. Examples of this are textiles and tapestry from PET (bottles). These lower grade plastics are also compressed into rigid board and used in a variety of applications, such as speed bumps and park benches, or ground into fragments for road fillers and rolled into table mats. Some might argue these processes actually represent ‘upcycling’, as they have dramatically prolonged the life expectancy of so-called single use products.

Chemical recycling

Chemical recycling is a term used for processes which break down materials into their component monomers and other substances, including fuel from hydrocarbons. One of the most prevalent processes in this category is pyrolysis, which uses heat at varying degrees and durations to break polymers into constituent monomers. This then enables the recreation of polymers so that the end products are indistinguishable from the virgin material.

This rapidly growing operation is much more complex and costly than re-grinding. Because of this, it’s generally targeted at materials that are hard to mechanically recycle, such as mixed materials and engineered polymers. None-the-less, this is hugely important as more and more products are being manufactured using composite plastics.

Composites are heavily used in medical devices and pharma products, including multilayer blister film and over-moulds for soft-shells, grips and seals, as well as insert mouldings and multi-material welded primary containers, among others. Although this is sometimes driven by aesthetics, more often in medical applications the composites are paramount for function, reliability, sterility and other essential requirements.

Another sustainability consideration is the energy fuelling the manufacturing processes in polymer production. More and more polymer processing plants have achieved, or are aiming to be, carbon neutral or even negative, for energy consumption. Much of the manufacturing lends itself well to being powered by fuel produced as a by- product of the process and is therefore self-sufficient. Others use wind or solar generated electricity. Some products have a sustainable label based solely on them being produced using renewable or scavenged energy.

Identifying solutions for sustainable moulded medical devices

As described, there are many options to consider when trying to create medical devices that have less of an environmental impact. Sustainable, compostable, recycling and more – there are now many options to consider in achieving a more sustainable medical device. Clearly identifying what you would like to achieve will help set the path for some of the new “greener” solutions on offer in our regulated industry.

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This article was taken from Team Consulting’s Insight magazine. Sign up for your own copy here.