Researchers at the German applied research organization collaborated with the Germany tech maker Bosch and the German home appliance maker Bosch and Siemens Hausgeräte (BSH) in a move that they hope will help make household appliances more sustainable.
The research partners were able to demonstrate that PP recyclates can be used in higher value-added applications beyond packaging.
They tested material recycled from automotive starter batteries that was suitable for manufacturing two kilo dishwasher case bottoms and a case bottom pin subject to mechanical stress when the dishwasher door was opened and closed.
The research calculated material characteristics by subjecting the case bottom test pins made from virgin and recyclate material to a set test force applied 100,000 times.
This volume of repetitions is roughly equal to the lifespan of the component in the application, according to the Fraunhofer. Additives were used to increase the strength and visual properties of the recyclate.
While the recycled parts were found to be 15 percent weaker than virgin plastics, nevertheless they demonstrated stiffness properties similar to the virgin material. A feasibility study concluded that the recyclate could replace virgin material in the application.
“While the recyclate is less strong – 15 percent weaker – it has similar stiffness properties to that of virgin plastic,” said Dominik Spancken, a research scientist at Fraunhofer LBF in Darmstadt. “More importantly, however, both materials behave exactly the same way in terms of plastic deformability. In summary, it is fair to say that the recyclate can handle the same stresses as virgin material.”
Switching to recycled case bottoms for dishwashers could have a significant positive impact on sustainability according to the institute’s own findings.
According to the Fraunhofer, based on a production figure of three million dishwashers produced annually the use of recyclates could save around 2,500 tonnes of crude oil annually, equivalent to the amount of oil transported in a 110-metre long river barge.