Martin Gadsby, VP of Optimal Industrial Automation, looks at how industrial automation can support the creation of a circular economy for medical plastics.
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Pill boxes inside a trash bin
Plastic can be found everywhere in medical and healthcare settings – in fact, we probably cannot imagine sanitary practices in the sector without it. Given that the material is so ubiquitous, it is no surprise that hospitals and other health centres generate large volumes of plastic waste. However, using data-driven chemical recycling strategies, this can be turned into a valuable resource, supporting circularity while potentially reducing costs.
However, the sector uses massive volumes of disposable medical plastics. It has been estimated that these represent approximately 25%-30% of landfilled medical solid waste. When looking at the UK National Health Service (NHS), 133,000 tonnes of plastic are disposed of every year, with only about 5% of this currently being recovered.
As these products are rarely recyclable at their end of life, they contribute to plastic pollution. Moreover, as most components are made from oil-based virgin raw materials, they are advancing the depletion of non-renewable sources. How can healthcare professionals overcome this?
Good chemistry
Currently, mechanical recycling is the most widely used strategy. However, this comes with key limitations in terms of the types of polymers that can be processed and produced as well as end product quality. Materials produced in this way typically feature inferior physicochemical properties, due to the presence of impurities and other contaminants, the popularity of mixed polymer blends, the presence of multilayer materials and the heterogeneity of the initial waste.
Chemical recycling methods, which are typically based on pyrolysis, depolymerisation or solvent-based selective polymer recovery, offer a valid alternative to address these challenges. They can address feedstock variability, remove coatings, dyes and other substances from medical equipment as well as separate the components of mixed materials. As a result, advanced chemical solutions can deliver high-purity monomers and polymers with virgin-like properties.
An obvious strategy for recycling facilities is to adopt robotic and/or machine vision systems to perform rapid and accurate sorting of large volumes of waste. When looking at the chemical reaction, separation and purification stages, automated process control strategies should be applied to optimise the operating conditions.
On the PAT watch
A highly effective solution is setting up self-regulating processes driven by Process Analytical Technology (PAT). More precisely, this framework consists of univariate and multivariate analysers that monitor the physicochemical properties of the plastic feedstock and process conditions, preferably via real-time, on-line measurements. Among the most suitable analytical devices that can be used are Raman and mass spectrometers, and nuclear magnetic resonance (NMR) instruments.
The data generated by these analysers is then shared with a PAT knowledge management platform, such as synTQ from Optimal Industrial Technologies. This platform combines the information via data fusion strategies and feeds chemometric and other predictive models to provide in-depth insights. These include determining the expected physicochemical properties of end products, when processes are complete and can move on to the next stage, as well as how the process can be optimised to meet quality and efficiency targets.
Enabling medical plastic circularity
Ultimately, smart chemical recycling plants can set up automatic feedback and feedforward closed-loop control. This can maximise yield, throughput, recovery rates and product purity while minimising cycle times, energy usage and solvent utilisation, if the recycling route requires it, as well as reduce waste and reworks. As a result, it is possible to limit the environmental impact of recycling activities and make them commercially viable, delivering monomers or polymers at a cost that can compete with virgin-based counterparts.
A skilled automation specialist with experience in implementing PAT-driven solutions, such as Optimal Industrial Automation, is a key ally in the creation of successful, future-oriented processing facilities for medical plastic waste. By partnering with an expert in the industry, companies can drive forward financially feasible circularity in the sector and benefit customers with economical, high-quality, greener products.