Martin Gadsby, director at Optimal Industrial Technologies, looks at how Process Analytical Technology (PAT) can slash the environmental impact of medical plastic manufacturing activities whilst creating valuable opportunities for process improvement.
Growing ecological awareness and stricter environmental regulations are driving positive changes towards greener, more sustainable practices when it comes to manufacturing with plastics. PAT offers a key tool to keep up with these trends and realise even the most ambitious green manufacturing initiatives.
Design flexibility, light weight, biocompatibility and the ability of some plastics to undergo sterilisation processes without downgrading their physicochemical properties are some of the many reasons why plastic is widely used in medical and drug delivery devices. However, this material has recently come under scrutiny due to its environmental impact.
PAT can improve the efficiency of raw material production, manufacturing and recycling processes whilst increasing the quality of the final products. This is a system for designing, analysing, and controlling Critical Process Parameters (CPPs) in manufacturing through timely measurements of Critical Quality Attributes (CQAs) defining Quality Target Product Profiles (QTPP).
Ultimately, by using MultiVariate Analysis (MVA) and chemometric models to link CQAs and CPPs, PAT aims to optimise industrial processes by offering an in-depth understanding of the manufacturing processes involved. This PAT process knowledge is presented in an easily accessible manner to plant operators via software platforms, such as Optimal’s synTQ knowledge management suite, allowing on-the-fly adjustments of CPPs to meet CQA targets.
The result can be greener manufacturing with lower energy usage, and less waste.
Solvent use
Key targets of PAT-led process improvement include reducing energy consumption, waste generation and substandard material production. These goals are some of the main objectives of green chemistry, a movement founded in the 1990’s1. As a result, businesses producing plastic-based medical and drug delivery devices can leverage this methodology to develop a system that promotes built-in quality as well as sustainability.
In addition to the general resources being used in the manufacturing of medical plastic, there are other resources whose use, and waste treatment, can be heavily reduced by PAT-led production, such as hazardous chemicals and solvents
Consequently, by using lower amounts of these chemicals, manufacturing facilities can minimise the environmental impact of their processes.2
Greener processes
Process optimisation also means shifting from batch processing to continuous flow, and PAT acts as the ideal gateway to continuous processing. This is inherently more sustainable than batch manufacturing, due to lower energy expenditure. For example, a number of pieces of equipment, such as extruders, do not need to go through cycles of heating at the beginning of every batch process and cooling at the end of it.
Advanced PAT knowledge management platforms, such as synTQ, also offer ‘digital twin’ functions. These further reduce the volume of resources used, waste generated, and energy consumed, by allowing medical plastic manufacturers to develop, run and test a process data flow before an actual, physical process is started up.
Greener quality testing
PAT’s contribution to developing a cleaner industrial environment does not solely influence the medical plastic manufacturing process, but also encourages the development and implementation of eco-friendly analytical practices in quality control.
The in-line testing procedures at the core of PAT greatly simplify the testing workflow. By doing so, test sample packaging, transport, storage and preservation activities are no longer taking place, as analysis is performed in-line. As a consequence, waste production and energy usage resulting from these tasks are completely eliminated.
Re-calibration is also heavily reduced when performing in-line measurements, further limiting reagent and energy consumption, as well as waste generation, by avoiding the use of calibration solutions, standards and reference materials.
The nature of the analytical techniques utilised in PAT-led quality assurance also contributes to lowering their environmental impact. Much of the analysis performed is non-destructive. Therefore, it does not generate any of the waste associated with material testing. Moreover, they do not require solvents for sample preparation.
A green way ahead
A substantial decline in waste formation, as well as resource and energy use, also results in substantial cost reduction, making PAT an interesting tool for businesses in any manufacturing sector. It is therefore clear how medical plastic manufacturers that have not yet implemented a PAT strategy are missing out not only on an opportunity to improve the environmental profile of their production processes and quality testing, but also the associated economic benefits resulting from resource and waste minimisation or avoidance.
References
1. Original “manifesto”: Anastas PT, Warner JC. Green Chemistry: Theory and Practice. New York: Oxford University Press; 1998
2. Hosam El-Din Mostafa Saleh and M. Koller (February 28th, 2018). Introductory Chapter: Principles of Green Chemistry, Green Chemistry, Hosam El-Din M. Saleh and Martin Koller, IntechOpen, DOI: 10.5772/intechopen.71191. Available from: https://www.intechopen.com/books/green-chemistry/introductory-chapter-principles-of-green-chemistry