While the use of recyclates in packaging is becoming ever more commonplace, when it comes to higher value-added applications brand owners and companies are more hesitant.
Batch variations have, in the past, made it difficult to obtain consistency regarding such aspects as strength, odour and appearance. Material properties not only differ from recyclate batch to recyclate batch, but also from those of newly made plastic.
As a result: “There is still a lack of trust in recycled materials,” said Dominik Spancken, a scientist at Fraunhofer Institute for Structural Durability and System Reliability LBF, in Darmstadt.
Seeking to demonstrate the potential of recyclates for use in higher-end applications and to generate more trust in these materials, researchers at the institute collaborated with Bosch GmbH and Bosch-Siemens-Hausgeräte GmbH (BSH) to investigate what recycled plastic could actually achieve, said Spancken.
Bosch first optimised recyclate derived from car starter battery housings, using additives to enhance the visual properties and increase the material’s strength. The research team then analysed whether the material was suitable for use in manufacturing dishwasher case bottoms, a component, weighing approximately two kilograms, forming the base structure of a dishwasher. It holds the side walls and housing ancillary components, such as the pump, status sensors and salt reservoir.
Based on a production figure of three million dishwashers per year, using recyclate instead of virgin plastic would save around 2500 tons of crude oil annually – equivalent to the amount of oil transported on a 110-meter-long barge. However, said the researchers, it needs to be processed before it can achieve properties that match those of virgin plastic.