Lightweight Construction and Long Fibers Save Energy With the Help of Simulations

In the project »DigiLaugBeh«, which is funded by the German Federal Ministry of Economic Affairs and Climate Action, our researchers are facing challenges on several levels at once: Digital twins are helping to optimize the caustic tank of washing machines in terms of materials. By simulating the components made of fiber-reinforced plastics, those involved in the project are finding out what a component must look like that will last a long time and at the same time make the appliances more energy-efficient as well as more resource-efficient.

Fiber-reinforced plastics and lightweight construction have become indispensable in the production of vehicles, but also in the choice of materials for household appliances. In washing machines, injection-molded components made of short-fiber-reinforced thermoplastics (SFT) have been used most often to date. They have fiber lengths of between 200 and 350 micrometers. New environmental labels have been in force throughout the EU since March 2021. These divide all washing machines into efficiency classes from A to G. Better and better appliances are coming onto the market and people are paying more attention to the certificates when buying. Labels with A and plus signs no longer exist.

Nothing Easier Than Washing – It’s the Plastic in the Tub That Counts

The demands on equipment and production have increased. Previous concepts using short fibers can no longer cope with this. The project shows that long-fiber-reinforced plastics are a good alternative. »DigiLaugBeh« focuses on a demonstrator on which we repeatedly validate and test the methods for digital design optimization. It simulates the caustic tank of a washing machine, which enables drying and washing in one device. This is already being produced in large numbers.

The process places high demands on the material in the tub – not only in terms of mechanical properties and service life, but also in terms of energy balance. Not every plastic can cope with caustic in the long term, and at the same time faster spinning and lightweight construction with long fibers are seen as the solution when it comes to saving energy. This also requires robust material. The tough plastic polypropylene is one way to solve this. The increasing fiber length (two to three millimeters in the component) extends the service life of the material.