What Factors Affect Machined Parts Cleaning?

Whether you’re having difficulty obtaining clean components, or want to improve cleaning efficiency, Turbex explains what factors affect cleaning and the variables to consider.

Once components come off your machine tool, it is important that they are cleaned of any residual oils, swarf and other contamination before advancing to the next process. Dirty components can have a big impact on the final assembly and, in some cases, are unacceptable for critical products. Whatever cleaning methods you require, it’s important to consider what factors affect cleaning. This will allow you to maximise the efficiency of your cleaning time and avoid any unnecessary rework or defective products that result in lost time and lost profits. Whether you’re having difficulty obtaining clean components, or want to improve cleaning efficiency, read on to find out what factors affect cleaning and what variables to consider with an industrial cleaning machine.

1. Components cleaning time

Spending extra time cleaning components can have a negative impact on production times. However, more time cleaning means longer agitation of the surfaces and longer chemical contact. This increases the likelihood of breaking up dirt and residues at the surface, ensuring a cleaner component.

Additionally, a longer cleaning time ultimately leads to higher costs. To minimise these issues, it’s generally desirable for the cleaning time to be kept reduced. To be more accurate, a balance must be achieved with the other factors that can impact cleaning quality.

2. Cleaning temperature

Many manufacturers keep their cleaning temperatures as low as possible to save fuel costs, but this can cost more money as it increases the time spent in the wash cycle. Higher machine temperatures increase the efficiency of your cleaning medium because they allow chemical reactions to occur much easier and faster. Additionally, the viscosity of dirt and residues will reduce with higher temperatures – causing them to be more easily penetrated and removed by your cleaning medium. 

Additionally, in spray wash systems, the wash temperature needs to operate above the temperature for the cloud point of the detergent.  If running below this cloud point, non-ionic surfactants (a constituent within the detergent) tend to have reduced cleaning ability and also foam heavily.

However, just as you have to do a balancing act with cleaning time, you must also do so with temperature. Higher temperatures can lead to higher operating costs, but lower temperatures can lead to poor cleaning performance.

3. The role of mechanical actions

To deepen your understanding of what factors affect cleaning, here’s an analogy: When you wash up in the kitchen at home, you don’t simply soak the dishes in soap to remove pesky grime – you also scrub the dishes. The same applies to machined component cleaning. Physically agitating your part in a cleaning solution cleans much faster than merely immersing it in said solution. Different mechanical actions, such as ultrasonic or spray cleaning, can accomplish cleaning of a much higher quality than a simple spray and wipe.

Ultrasonic cleaning can clean hard-to-reach spaces, such as blind and tapped holes where dirt and residue lurk. Ultrasonic cleaning uses sound waves to create microscopic bubbles (cavitation) that scrub the surfaces of your component when immersed in a cleaning solution. Spray cleaning uses an array of nozzles to clean the surface.

Machines that clean using these methods are highly effective. However, too much agitation, especially to delicate components with special coatings or platings, can cause damage. Therefore, you need to know what degree of cleaning you are trying to achieve.

4. Solution chemical reactions

The type of cleaner and its chemistry dictates the aggression of your cleaning process. Depending on your needs, a simple “soap” and water solution may be sufficient – or you may require something more complex, like aerospace-certified cleaners. Following many machining processes, components remain coated with coolant. Water-based (aqueous) cleaning solutions are best for components machined with a water-soluble coolant, so you’ll likely gravitate towards them in this case. However, more complex parts manufactured using cutting oils may require more sophisticated, solvent-based solutions.

When cleaning components machined with water-soluble coolants, an aqueous cleaning chemical that matches the pH of the component’s material should be used. Chemicals with higher alkalinity can discolour or etch softer metals, whereas harder metals may require a chemical with higher pH to effectively remove coolant residue. Additionally, it may be important to use softened or deionised water to avoid unwanted contaminants. In contrast, solvent-based chemicals are best for components machined with neat oil-based coolants or made with metals that react badly with aqueous solutions. Industrial cleaning machines are generally used with cleaning solutions that are tailored to be used with specific materials to accomplish the best possible clean.

In summary

All things considered, component cleaning is a much more complicated process than meets the eye. It can be an enduring and expensive process – but it doesn’t have to be. If you know your expectations regarding quality and cost, then we know the optimal solution for you. Our precision component cleaning machines – whether you need a single ultrasonic or spray cleaning machine or an entire automated chemical cleaning line – are manufactured to the utmost quality. Reach out to a Turbex representative today.