A new cascade process for cleaning aluminium parts saves resources – around half of the required energy and fresh water as well as about a quarter of the CO2 emissions.
If vehicles are lighter, they consume less energy per kilometre. This is why components made from the lightweight metal aluminium are being used more and more frequently – their share has doubled over the past 20 years. Lightweight construction thus contributes to reducing CO2 emissions during the use phase. However, the entire life cycle must be considered for a vehicle’s CO2 balance. This also includes the emissions generated during production.
Link to the original article – ressource-deutschland.tv: Efficient surface technology in lightweight construction – Cleaning of aluminium parts
After casting, the surfaces of the aluminium parts are heavily soiled. Before they can be further processed in the automotive industry, dirt must be removed from their surfaces. This cleaning requires large quantities of water, chemicals and energy. To reduce this, Holder GmbH Oberflächentechnik has developed a new resource-saving process for cleaning aluminium parts.
Cleaning is carried out in a cascade process across several baths. Degreasing takes place in the first bath using surfactants, salts and ultrasound. The parts are then rinsed in three further tanks. The water displaced during immersion is collected and fed back into the cleaning process. This reduces the amount of fresh water required and the amount of wastewater that needs to be treated. Chemicals are also saved, as they are returned to the degreasing bath together with the water from the first rinsing stage. During drying, a dehumidifier and a convection dryer were combined for higher energy efficiency. The air flowing in from one side of the dehumidifier is extracted again on the other side and recirculated. All the energy for the baths and the dehumidifier is generated in a combined heat and power plant.
With this process, the medium-sized company from Baden-Württemberg saves around 13,000 m3 of fresh water, 20 tonnes of chemicals and 770 tonnes of CO2 per year. The payback period is estimated at 3 to 4 years.
The development of the new plant was funded by the Federal Ministry for the Environment as part of the Environmental Innovation Programme (UIP).