Cleaners – and often forgotten key in machine maintenance

Cleaning fluids are a vital part of the maintenance process in all industry. They’re used to remove oil, grease and solid contaminants from components and machine parts. The right fluids and settings can save energy and money by extending the life of machining fluids, reducing corrosion and ensuring more reliable processes. But cleaning and cleaners rarely come up in conversations about maintenance and production. Even so, they certainly deserve more attention.

In this blog post, I’d like to share a few facts that make it easier to understand how cleaning works, what affects the results, and why small details can often make a big difference.

It’s about the big picture

To understand industrial cleaning, it might help to think about your own kitchen. Imagine you’re washing up a frying pan after frying something in fat. What will work best? Cold water won’t get you far. But add heat, washing-up liquid and a dish brush, and now you’re getting somewhere. The same principle applies in industry: the results depend on the interaction between time, temperature, mechanical processing, concentration and the type of detergent. This also means that cleaning never comes down to the cleaning fluid alone. 

If a cleaner is to work, it has to be appropriate for the type of contamination, material and process. A cleaner that works great on grease in one process, may not work as well in another. The principle of ‘like dissolves like’ explains why some contaminants respond readily to one chemical character, whereas others require different properties entirely. Fat dissolves fat, polar substances dissolve polar substances, and so on. If the cleaner’s chemical structure is not right, the process won’t get clean however much you wash it.

Cleaning is rarely simply a case of ‘running a cleaner through the system’ or ‘immersing the parts in a bath’. The choice of cleaning method is also a factor (spray, immersion, ultrasound?), as are the individual stages of the cleaning process – wash, rinse, dry, etc. So you not only have to know what’s being washed, you also need to know what contaminants need removing and what kind of washer is being used.

What is contamination?

Rust protection, oil, limescale, paint, adhesive, rust, soot, water, old detergent residues… You name it, contamination can be anything. All kinds of substances and conditions can be contaminants, whether they’re in the wrong place or present at the wrong time. It’s usually pretty easy to do something about visible dirt and contamination. It’s the stuff you can’t see that’s far harder to detect and deal with. The problem with contamination is of course not only whether or not it’s visible; it also affects the customer’s process. Moisture and particles can cause corrosion beneath the surface, a thin patch of oil can reduce adhesion when painting or coating, and so on. The wrong kinds of residue can affect subsequent processes, even if the machining has been done perfectly.

Small things can ruin the whole

Sometimes the results don’t live up to expectations, even though conscious choices have been made for the process. It’s worth bearing in mind that cleaning issues rarely arise because a single major error suddenly causes problems. In most cases it’s down to a number of minor deviations which jointly pull the whole process off course. Perhaps the temperature’s a little low, a nozzle or two start getting blocked or are misaligned, there might be leaked oil or particles could be building up in the system, or maybe an oil separator isn’t doing its job…

You may only notice that minor details are affecting the overall system when you see a slightly lower level of cleanliness, or more foam than usual. But not long afterwards there will be knock-on effects like rust, longer drying times, an increased risk of microorganisms, poorer stability in the process, a shorter service life for the cleaning fluid and other unpleasantness.

And if the cleaner is also affected by other fluids in the process, such as cutting fluids, hydraulic oils or rust inhibitors, it’s also important to know how compatible they are. Even good products can produce poorer results if they’re used in the wrong place or mixed with products they simply don’t go with.

Clean cleaners, clean parts

The good thing about problems that arise from minor details is that they generally don’t take too much effort to put right and get your results back on track. What you must do, though, is keep a close eye on your cleaning routines and take even the slightest signs seriously. 

One key is to make sure the cleaning fluid itself is clean, otherwise it will gradually stop serving its purpose. The washing machine itself also needs to be kept clean. After all, the cleaning fluid has to take care of particles and oil – but filters, magnetic bars, strainers and oil separators also have to function correctly to prevent contaminants from accumulating in the system. Whether your cleaning is based on spraying, immersion or ultrasound, it really has to get at the surface in question if it’s to do its job properly. 

The earlier you detect a change, the easier it usually is to make adjustments. So I would definitely recommend regular checks on both the washing machine and the cleaning fluid. What does the fluid look like? Does it smell different? Is it different in any way to how it was before? By keeping tabs on the smell, appearance, particle content, pH, concentration and cleaning equipment, you can detect problems in time and keep your cleaning fluid working longer. Minor adjustments can make a major difference to your systems' cleanliness and operating reliability, and also your finances.

Sustainable cleaning – but hazardous waste after use?

A lot of cleaning fluids today are designed to be sustainable and contribute to a healthy work environment. One question I’m often asked is, why is an eco-friendly, sustainable cleaning fluid always classed as hazardous waste after it’s been used? The answer lies not in the cleaning product, but rather in the kind of contamination it has dealt with. In operation, the cleaner gathers up oils, metals, particles and other contaminants from the various stages of the process. This is what produces cleaner parts, but it’s also why, under national legislation, the fluid is considered hazardous waste after it has been used. 

This is one reason why it’s important to ensure the fluid lasts as long as possible, without compromising the results. Other reasons are functionality and, of course, company finances. A fluid that works stably over time reduces the need for regular changes, process downtime and unnecessary waste.