Swedish compounders Hexpol TPE, a company specialising in thermoplastic elastomers and Polykemi, a producer of thermoplastic compounds, have collaborated on developing material combinations with a reduced carbon footprint for two-component injection moulding applications.
Selecting two materials for a 2K part is not doubling the difficulty; it is squared, the two compounders noted.
Solutions were created to demonstrate the possibilities of reducing the product carbon footprint, as well as of increasing recyclability and optimising adhesion.
The two companies have done substantial work in the field of sustainability, Hexpol via its Sustainable Materials Lab and Polykemi with its Materialsmart life cycle analysis project. This enabled them to provide cradle-to-gate Product Carbon Footprints (PCF) and calculate the Global Warming Potential (GWP) per kg of material.
”Making an informed choice is key when decarbonising, and making the consequences clear is the first step on this journey,” said Henrik Palokangas, a sustainability specialist at Polykemi.
The PCF data shows that switching from a combination using fossil fuel-based ABS from Polykemi, that is overmoulded with a fossil fuel-based TPE from Hexpol TPE, to a recycled PP and TPE with bio-circular attributed content, can yield a 77% reduction in carbon dioxide emissions. The companies say this combination can also provide end-of-life and recycling compatibility benefits.
Combinations using mechanically recycled ABS with bio-circular attributed TPE were also tested, resulting in a 57% reduction in carbon dioxide emissions compared to the fully fossil-based equivalents. The TPE has bio-circular attributed content via the mass balance principle from 2nd generation feedstocks.
“To bring real change and deliver the needed transition of the plastics industry, we must collaborate. This project is about taking our collective know-how to enable combinations with the lowest carbon footprint and highest recyclability possible, while also giving assurance on the materials' adhesion performance and durability," concluded Klas Dannäs, sustainability director at Hexpol TPE.
