Tests show it really saves fuel! Recycling plastic to make dishwasher bases could save 2,500 tons of

       Researchers at the Fraunhofer Institute in Germany recently collaborated with Bosch to find that recycled plastics have similar properties to new plastics and can be used to make parts for dishwasher bases.

        Recycling plastics to make dishwasher bases is expected to save 2,500 tons of crude oil

        The base of a dishwasher weighs about 2 kilograms. It supports the side walls of the dishwasher and houses pumps, status sensors, salt tanks, etc. If the base can be produced with recycled materials, it will help promote the sustainable development of household appliances. According to the production data of 3 million dishwashers per year, if the base is made of recycled materials, about 2,500 tons of crude oil will be saved each year, which is equivalent to the amount of oil transported by a 100-meter-long barge.

        Recycled plastics play a key role in environmental protection. Although some packaging is already made of recycled plastics, technical experts and companies are reluctant to use them in high-end products. In the final analysis, this is mainly because these recycled plastics processed from waste plastics have changed in strength, smell and appearance, which are different from new plastics. "To put it bluntly, people still lack trust in recycled plastics," said Dominik Spancken, a scientist at the Fraunhofer Institute.

        But if recycled plastics are processed effectively, their properties can be adjusted to match those of new plastics. Fraunhofer Institute, in cooperation with Bosch GmbH and Bosch-Siemens-Hausgeräte GmbH, hopes to change the current situation of recycled plastics and prove that recycled plastics are trustworthy.

        Bosch first optimizes the recycled materials from the car battery housing, such as using additives to increase the material's strength and improve its appearance.

        Can it withstand 100,000 pressure loads?

        After the recycled materials were optimized, the researchers made a test sample to test its load capacity for mechanical stress - using an automated program to apply pressure 100,000 times. This number is calculated based on typical applications and load ranges for large white appliances, and it sets the limit for how much pressure the material must withstand without being damaged.

        In addition, the 100,000 cycles of applied pressure mainly take into account the mechanical stresses that the finger-shaped pins at the bottom of the dishwasher housing are subjected to when opening and closing the dishwasher door. It also represents the area at the bottom of the dishwasher housing that is subject to the greatest pressure load. If the dishwasher door is assumed to be opened 15 times a day for 18 years, the dishwasher will be opened 100,000 times during its entire life cycle. Whether the finger-shaped pins made of recycled plastic can withstand these pressures is the focus of the research.

        "Although the strength of the recycled plastic is 15% weaker than that of the new plastic, it still has similar stiffness properties to the new plastic. What's more, the two plastics behave exactly the same in terms of deformation," said Fraunhofer researcher Spancken.

        Are components made of recycled plastics strong?

        To confirm this result, the researchers tested the components themselves in addition to pure material tests. "We calculated the material properties from the material tests. Using these characteristic values, we developed an evaluation method to check whether the finger tips are durable," the scientist explains.

        In other words: The team clamped the base pins made of virgin plastic on a test bench and applied loads to simulate the loads that occur when using a dishwasher, especially when the door is opened and closed. Given that the heat radiation from floor heating and the dishwasher can heat the pins to 50 °C, the team also adjusted the test temperature to 50 °C. At this ambient temperature, the researchers calculated how much force is needed to break the pin and how long it can withstand the opening process. The researchers used the experimental data to create a proven calculation and design method, which was then applied to tests on recycled plastics to infer how pins made of recycled plastic behave under pressure.

        The experimental results showed that the elasticity values of pins made of recycled plastics are only slightly different from those of pins made of new plastic. The Fraunhofer Institute said that the feasibility study shows that recycled materials can be used in the base of dishwashers, which will help increase the use of recycled plastics in household appliance parts.