Component cleaning

Hayley Everett

When considering the production of an aircraft or vehicle, component cleaning is rarely the first thing that comes to mind, despite being essential for their reliable and safe function. So, how are cleaning solutions being optimally adapted to ensure quality, efficiency and sustainability?

In both the aviation and automotive industries, component cleaning is one of the production steps that is relevant to quality and safety. The requirements to be met in terms of technical cleanliness vary greatly. In heavy trucks, for example, the combustion engine is still the preferred drive system, while battery and fuel cell-based electromobility is increasingly gaining momentum in the passenger car sector. In aviation, the trend is also toward more energy-efficient engines. As a result, components, manufacturing technologies and processes are changing. When it comes to cleaning the various components, this leads to modified and new requirements with frequently higher cleanliness specifications. In addition to particulate contamination, filmic contamination is increasingly coming into focus.

As a full-range supplier of future-oriented, globally available equipment for industrial component cleaning, surface treatment and automation, Ecoclean and UCM - the division of the SBS Ecoclean Group specialising in ultra-fine and precision cleaning - develop and manufacture cleaning solutions that are optimally tailored to applications within the very different tasks in the aviation and automotive industries.

Wet chemical cleaning

Optimally adapted solutions for wet chemical cleaning include standard and special processes for batch and individual parts cleaning with water-based media and environmentally compatible solvents. Batch processes, in which the workpieces are cleaned in batches as set goods or as bulk material, are usually used for turned, stamped, and bent parts of brake, steering, injection and sensor systems, as well as transmissions. When selecting the cleaning medium, the chemical principle “like solves like” provides guidance. This means that polar contaminants such as cooling emulsions, polishing pastes, salts, abrasion and other solids are normally removed using water as the polar cleaning medium combined with pH-neutral, acidic or alkaline cleaners. For mineral oil-based (organic, non-polar) contaminants such as machining oils, greases and waxes, solvents such as non-halogenated hydrocarbons or chlorinated hydrocarbons are usually used. Modified alcohols (3-butoxy-2-propanols) have lipophilic and hydrophilic properties and are therefore able to remove both non-polar and polar impurities to a certain extent.

In order to achieve the given cleanliness specification quickly and effectively, and thus to minimise the proportion of cost per part cleaned, the cleaning effect of the medium is supported by various physical process techniques. Commonly used technologies are spraying, immersion cleaning, ultrasonic and injection flood washing, and in solvent cleaning, vapor degreasing. For single-piece cleaning, for example powertrain, engine and turbine components, in short cycle times, transfer systems and robot cells which can be individually adapted to the application are available. By combining spray treatment with injection flood washing and, in some cases, high-pressure applications, specified cleanliness specifications are achieved quickly, reproducibly, and economically.

Deburring and cleaning in one process

The increasing requirements for burr-free and clean hydraulic and pneumatic systems, motor, pump and valve housings, nozzles, gear parts and other mechatronic components can be met efficiently and reliably with the EcoCvelox. The system combines 5-axis high-pressure waterjet deburring with various processes for component cleaning and drying.

Effective surface treatment

Ecoclean’s EcoCbooster technology has been developed for tasks such as surface activation prior to thermal coating (e.g. of cylinder liners or brake discs), roughening, de-coating, de-rusting, and paint stripping, as well as for selective cleaning of weld seams. Compared to other solutions for applications in the ultra-high-pressure range, significant savings in energy and maintenance costs can be realised. This is made possible by this patented process technology: By using ultrasound, the prestressed water column becomes an ultrahigh-frequency pulsating water-jet after exiting the nozzle. As a result, it has significantly higher kinetic energy, so that treatments can be carried out in the medium pressure range (300 to 700 bar) without adding abrasives.

Full or partial surface dry cleaning

New products and changes in manufacturing and joining technologies are making dry cleaning processes increasingly important, whether it is to remove filmic contamination from joints, clean electronic components and assemblies, remove powder residues from additively manufactured components, or for assembly-integrated cleaning. For these and many other applications, the plant manufacturer has developed a special toolbox for cleaning processes with atmospheric pressure plasma, laser, CO2 snow, processed vacuum air, as well as saturated and dry steam. The removal of particles produced during the manufacture of stators during the processing of hairpins and the assembly of electric motors are among the classic tasks of dry cleaning with compressed air and vacuum technology. Solutions optimally adapted to the task at hand, which can also be subsequently integrated into the assembly lines, ensure the reliable operation of these components. This type of dry cleaning is also used for power electronics components and assemblies.

Laser technology can be used both to partially clean a surface and to partly roughen or structure it as required, for example for a subsequent bonding process.

Regardless of whether wet chemical or dry cleaning is used, process development and validation should always be carried out through cleaning trials with original parts. Ecoclean has its own extensive test centres for this purpose.

Doris Schulz is a Journalist at Schulz Presse