Co-Injection Moulding Bioplastics: Investigating Procedure and Performance

To help combat environmental issues like climate change and landfill waste, bioplastics are being developed to provide renewable and/or biodegradable polymer options. Compostable, corn-based polylactic acid (PLA) is strong and stiff, but brittle. Polycaprolactone (PCL), a petroleum-based compostable polymer, is very tough but has poor strength. Combining these plastics by melt blending is an established method to create a new material that balances their complementary properties; however, alternative processing methods have the potential to be more successful. Co-injection moulding is a manufacturing technique that combines polymers in a layered structure; it can help to produce more aesthetically pleasing products, reduce processing steps, and may result in improved mechanical performance. Determining operating parameters for optimal co-injection conditions for PLA and PCL will be investigated and final products will be compared to similar melt blended samples. Emphasis will be placed on proper part formation and impact resistance in evaluating a successful co-injected material.

Acknowledgement: The financial support from the Natural Sciences and Engineering Research Council (NSERC), Canada for the Discovery grants individual (to Mohanty) and the Ontario Ministry of Agriculture & Food and Ontario Ministry of Rural Affairs (OMAF-MRA) to carry out this research is gratefully acknowledged.