Component cleaning for changing requirements in the automotive industry

The changes in the automotive industry are also presenting parts manufacturers with new requirements in component cleaning. A holistic view of the process chain is required in order to meet them in a technically and economically optimal and sustainable manner.

The change in mobility has an impact on industrial component cleaning. Modified and new components, for example, have to meet stricter requirements in terms of particle cleanliness. "Depending on the component, this not only includes stricter specifications regarding the number and size of particles, but also, for example, specifications regarding fibers in workpieces for traction batteries, as these can cause short circuits when wet," reports Kerstin Zübert, application engineer at Hermann Bantleon GmbH. "The use of other production technologies, such as adhesive bonding and modern welding processes, also places higher demands on surface cleanliness. Residual film contamination plays an important role in this area," adds her colleague Julian Fischer. Another aspect that requires adapted cleaning processes are changes in materials. Examples of this include parts that were previously made from cast steel now having to be cast from lighter aluminum materials or components for hydrogen drive injection systems having to be replaced with stainless steel instead of cast iron. "We are also noticing that more and more companies are expanding their value chain in order to be able to supply fully assembled and, in some cases, coated assemblies instead of individual components. The technical cleanliness of production and assembly lines as well as production equipment is also coming more into focus, i.e. topics that are dealt with in VDA 19, Part 2," explains Kerstin Zübert.

Seeing component cleaning as the sole solution for this task does not work in most cases - at least not in an economical and resource-saving way. This is because upstream processes have a significant influence on the cleaning effort and result. It is therefore advisable to look at the entire process chain. As a globally active system partner to the metalworking industry, Hermann Bantleon GmbH supports this holistic approach in close cooperation with customers and, if necessary, cleaning system and filter manufacturers. The Ulm-based company develops, produces and distributes lubricants for the machining and forming industry as well as cleaning and corrosion protection media worldwide. This product portfolio is complemented by a wide range of services, which always include sustainability aspects.

Regardless of the cleaning task, it is important to avoid or minimize contamination. After all, anything that is not applied to a component does not need to be removed. This is not a new insight, but it is still often neglected. "If you go through the production process together with the customer with this process idea in mind, there are often starting points in the upstream processes to improve the cleaning result," says Julian Fischer from experience. It is often comparatively easy to implement measures that can reduce the cleaning effort or ensure that the required cleanliness specification is achieved with the existing cleaning equipment. Customers often benefit from the company's excellent network with other industrial cleaning technology providers. "If, for example, the particulate cleanliness is insufficient, we may go to the customer together with a filter manufacturer to find a solution that retains the particles during the production process and prevents them from reaching the component," explains Kerstin Zübert.

Using a different approach, a large automotive supplier was able to eliminate a particulate cleanliness problem during cleaning with an existing solvent system. Instead of placing the components in the cleaning system after production, they are rinsed with a dewatering corrosion protection product during the production process. This is sufficient to meet the particle requirements for this component. The previous cleaning process can be dispensed with and with it the effort involved in collecting, feeding and discharging the parts. In addition, the thin corrosion protection layer allows the parts to be stored for a certain period of time without impairing the subsequent joining process. This has also eliminated previous corrosion problems and reduced rejects to zero.

Whether the decisive factor for process optimization is higher cleanliness requirements, changed materials or the demand for reduced production costs, the solution can also be an adapted cleaning medium. Often contradictory requirements have to be reconciled. This is demonstrated by an application in which large quantities of formed parts with particulate cleanliness specifications have to be cleaned as bulk material. "Due to the contamination to be removed, this would actually be a task for aqueous cleaning. However, as this cannot ensure that all parts come out of the system dry, we have developed a new solvent formulation that meets both requirements - particulate cleanliness and drying," reports Kerstin Zübert. In water-based cleaning, lower cleaning temperatures are one of the current topics for reasons of economy and sustainability. For example, instead of the classic 65 °C, an identically good result must be achieved at 45 °C with the same process. "To ensure this, it is essential to take a close look at the customer's existing cleaning technology and test the possibilities together. This is the only way to rule out negative effects such as increased energy consumption during drying," notes Julian Fischer.

Both when redesigning and optimizing cleaning processes, it is ideal for an efficient and sustainable solution if the customer involves the media manufacturer and, if necessary, the cleaning system manufacturer in the planning at an early stage. (OM-10/24)