Thin-walled high impact PLA injection moulding
Biodegradable, recyclable, food-safe and transparent. Until now it was an impossible combination, the thin-walled injection moulding and PLA. Researchers from Wageningen University Food & Biobased Research, SFA Packaging and Rodenburg Biopolymers have developed an innovative PLA compound. This material is ready for production, thin-walled injection moulding and even has a higher impact resistance!
Biodegradable, recyclable, food-safe and also transparent. Until now, it was an impossible combination for thin-walled injection moulding. Researchers from Wageningen University Food & Biobased Research, SFA Packaging and Rodenburg Biopolymers joined forces and developed the solution.
Thin–wall injection moulding with PLA – We did it!
‘Thin-walled injection moulding of PLA is difficult, because it does not flow sufficiently in the mould,’ says Niels L’Abée of SFA Packaging. ‘PP liquefies very thinly under high injection speeds, PLA maintains almost the same viscosity. This so-called “shear thinning effect”, the thin liquefaction under high injection speeds, is necessary to make injection moulded objects with a thin wall. The better a plastic flows, the thinner you can make the object. We have developed and patented an additive that makes PLA as fluid as PP and also retains the desired mechanical properties. This makes it possible to make all kinds of packaging, such as tomato buckets, salad trays, butter tubs and so on. It is even possible to make fully bio–based IML (printed packaging).‘
Biodegradable plastic (PLA): PLA stands for polylactic acid, better known as biodegradable plastic or bioplastic. It is manufactured from 100% renewable resources. It is obtained by fermentation of starch from, for example, maize or sugar cane.
Properties of PLA: PLA is a transparent, relatively brittle material, and similar to PS in terms of gloss and clarity. The strength of PLA is about the same as that of PET. PLA is resistant to fat and prevents loss of flavour and aroma. PLA can withstand temperatures from 0°C to +40°C.
Breakdown process of PLA: PLA can be broken down in biological industrial composting systems. The material is then broken down to lactic acid at high tempratures and humidity over a period of 45 – 60 days, and can then be converted to monomers or polymers. It can also be broken down by micro-organisms into carbon dioxide, water and organic material.
‘With PLA, you create additional end–of–life options. You can compost it and recycle’
Wageningen University & Research