Future-proofing parts cleaning

Louise Smyth

Assessing the trends – and the new challenges – in industrial parts cleaning

The cleaning of industrial parts is now widely acknowledged as a key value-adding step in the overall production chain.

But new trends are posing new challenges for the cleaning of industrial parts and surfaces.

It’s the same story in the automotive industry, the component supply industry, mechanical engineering, aviation, precision engineering and many other sectors of modern industry: the cleaning of parts and components is essential to preventing quality issues further downstream – eg, at stages such as coating, adhesive bonding, welding, tempering and assembly – as well as for the proper functioning of the finished product.

The cleaning of industrial parts and surfaces has thus gained the recognition as a value-adding step in manufacturing chains, and a major factor in staying competitive.

Trends impacting cleaning technology

In many industries, the main emphasis after machining and forming processes used to be on the removal of particulate contaminants using wet chemical cleaning methods.

The removal of film-type contaminants has been a priority, notably when preparing parts and surfaces for coating, welding, tempering or adhesive bonding. The need for these cleaning steps is unlikely to change in the future. But new trends are posing fresh challenges for the cleaning of parts.

One example is the trend towards ever smaller and more complex parts and components expected to perform better and last longer.

Other trends, such as shorter product life cycles, smaller production runs (including one-offs), the use of new materials and combinations thereof (typically in lightweight construction), new production processes and the onward march of globalisation, all have a direct impact on parts cleaning.

Not to mention major technical developments such as electromobility, autonomous driving, and the reconfiguration of production processes in line with Industry 4.0.

More adaptable systems

Wet chemical cleaning will undoubtedly remain the most common technology used.

However, to be prepared for changing market needs and shifting technical demands, flexibility regarding the future viability of parts and surface treatment facilities is becoming increasingly important.

The parts cleaning industry is already anticipating emerging needs by designing plants with built-in adaptability to handle different types of parts, different standards of cleanliness and alternative cleaning methods.

This means installing more efficient ultrasound systems, pressure pumps and filtration systems, and also incorporating technical developments that enable plant operators to adjust the cleaning parameters to match the specific size and geometry of the parts passing through the system.

The ability to quickly and easily swap out cleaning tools such as spray units is one such development, along with the separation of cleaning and drying operations in the case of water-based cleaning.

Growing demand for fine and ultra-fine cleaning

The requirement for components meeting ever-higher standards of cleanliness is coming on the one hand from established high-tech fields such as semiconductors, micro technology and electronics.

The task here is to remove surface contaminants in the form of particulates and films, as well as water stains and discoloration, while biological and ionic contaminants are also an issue in some fields.

On the other hand, new types of components such as those used in the electrification of drivetrains or in driverless cars are posing new challenges for the parts cleaning industry.

Such components come with a range of exacting performance requirements: the ability to conduct electricity and support continuous current flow; good coatability; and, in the case of optical sensors, 100% guaranteed functionality. To remove particulates and surface films and achieve the requisite degree of cleanliness, manufacturers are increasingly turning to fine and ultra-fine cleaning processes.

Alongside the basic design and configuration of the cleaning plant (number of treatment stations and drying facilities) plus appropriate process technology (e.g. multi-frequency ultrasound), cleaning chemistry and process design, other technical aspects also need to be considered. These include such things as flow optimisation, parts carriers, piping, conveyor automation and air management.

Inegrated and adaptive processes

The trend towards intelligent, networked production processes – enabling manufacturers to achieve greater productivity, improved product quality and flexibility while at the same time reducing their costs – is also driving changes in industrial parts cleaning.

Already available now are fully automated inline plant solutions that can clean and dry bulk goods such as screws, and then transport them onwards to the next processing stage.

The latest intelligent generators for use in ultrasonic cleaning can now configure themselves and then monitor and optimise their own operation. This means, for example, that the optimum operating frequency can be automatically determined and set before the ultrasonic pulse is triggered.

The continuous monitoring and logging of plant and process parameters in wet chemical cleaning plants is now a common feature.

Plants can now be equipped with sophisticated instrumentation for the continuous inline monitoring and control/adjustment of cleaning baths.

These systems not only permit accurate documentation of operating parameters during cleaning, but can also be used to inject additional cleaning agent into the bath as required, and the process is fully automated, needing no intervention by the machine operator. Initial solutions for the inline monitoring of cleaning results are also now available; these typically use fluorescence measurement technology to check for the presence of any film residue.

Selective dry cleaning

Selective dry cleaning of functional surfaces and designated areas of components prior to adhesive bonding, sealing or laser welding, as well as pre-assembled parts, using CO2 snow blasting, laser cleaning or plasma cleaning techniques, has hitherto been something of a niche specialty.

However, the selective cleaning of functional surfaces is set to become more mainstream in the future, given that a single workpiece can present a range of different cleaning challenges, depending on the degree of surface cleanliness required for selected areas destined for further processing, or on the use to which the component will be put.

The fact that inline-capable processes are easily automated has also helped to drive this trend.

Now becoming much more widespread, lightweight construction – which typically uses aluminium, composites and new combinations of materials – is another area where dry cleaning processes have become increasingly important. One example is the use of CO2 snow blasting by the manufacturers of electric cars to clean plastic body panels and moldings prior to painting.

Meet the parts cleaning experts

Answers to the questions raised here and many other questions on all aspects of industrial parts cleaning can be found at parts2clean.

The leading international trade fair for parts and surface cleaning takes place from October 24-26, 2017 at the Stuttgart Exhibition Center in Germany.

The show provides comprehensive information about cleaning systems, alternative cleaning technologies, cleaning agents, clean room technology, quality assurance and test procedures, cleaning baths and tanks, the disposal and conditioning of process media, handling and automation, services, consultancy, research and trade publications. The three-day parts2clean Forum is also a valuable source of know-how on various aspects of industrial parts and surface cleaning.

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