The plastics processing industry is caught up in the challenges of the energy transition and the circular economy. The search for the most sustainable polymers is on [we will be leading with a PhD on the topic]. But what are sustainable polymers?
To orient ourselves in this changing world, we spoke with Marco Scatto, an industrial chemist specialised in polymer science and author of 23 publications and 5 patents in this field. With Stamplast, Scatto conducted a series of refresher courses for all areas of the company to standardise and develop skills in sustainable polymers.
It is easy to say ‘plastics’, but there is a world of very different materials behind this word. How to get your bearings?
“Behind the word plastic there are a myriad of polymers. In particular, the ones we mainly encounter in everyday life are thermoplastic polymers, i.e. polymers that can be processed at their melting temperature with technologies such as extrusion, injection moulding, etc., i.e. all secondary polymer processing technologies. They can melt at temperatures around 200°C such as polyolefins (PP, PE) or above 250°C (polyesters) up to the 300°C of polycarbonate (PC)’.
What makes one plastic material more sustainable than another?
“What makes one plastic more sustainable than another can be both the origin of the monomers that characterise it (whether biobased, i.e. of biological and non-fossil origin) and the end-of-life (whether recyclable or compostable biodegradable). Today, we can have polymers that are biobased but not biodegradable and compostable, which we count among the sustainable polymers, as well as polymers that are biodegradable and compostable that are totally, partially or not biobased.
The best way to give an objective assessment of the sustainability of certain polymeric materials is to carry out Life Cycle Assessments (LCA) on polymeric items. This can show the real reduced environmental impact of articles made from sustainable polymers such as biopolymers or polymers from recycling (mechanical or chemical) compared to polymers from fossil sources”.
What challenges are faced by those who, like Stamplast, want to invest in their ability to process more environmentally sustainable materials?
“Injection moulding today can also involve sustainable polymers. Today, the leading manufacturers of bioplastics and recycled polymers also offer so-called ‘injection grades’, i.e. polymers with rheological characteristics suitable for processing with injection moulding machines such as Stamplast’s”.
What scenarios do you see ahead for the plastics industry?
“The plastics industry is facing a scenario of momentous change. Never before have consumers and end customers in a wide variety of sectors, from cosmetic packaging to sports systems and food packaging, been interested in using more sustainable polymers than traditional ones. Sustainable polymers make it possible to achieve sustainability goals that also have an impact on sales’.