Acquiring the appropriate parts washer – a machine where dirty parts, components and equipment can be cleaned – is not as easy a task as it may seem. As with any piece of shop equipment, not all parts washers are created equally.
Moreover, parts washers are offered in a range of cleaning solutions, specifications and levels of cleanliness, with a host of options. There are also different environmental concerns for the various types of parts washers.
To get the lowdown on parts washers, I contacted Safety-Kleen, a leading North American used oil recycling and re-refining, parts cleaning and environmental solutions company which provides a broad set of environmentally-responsible products and services (www.safety-kleen.com), and spoke with Sean M. Spaziani, the company’s marketing director for environmental services and products.
What are the most common cleaning methods used by parts washers?
Spaziani says the most common cleaning methods used by parts washers are manual, automated, ultrasonic and immersion agitation.
Typically a sink on a drum style or a vat style design.
Manual parts washers are best suited for a low volume of cleaning – generally less than 45 minutes per day, says Spaziani. They are also ideal for smaller parts where the contaminants can be removed with a brush under low pressure flow and the parts do not require a high level of clean.
Automated parts washers are intended for operations where parts are cleaned more than 45 minutes per day. In this case, as a general rule, transitioning to an automated process would actually save money, he says.
Other considerations for automated cleaning:
- The number of parts cleaned per day requires a more automated approach.
- The parts being cleaned have a certain design where they can’t be cleaned effectively through a manual process (i.e., blind holes).
- The level of clean required cannot be achieved in a manual process.
Spaziani says the most common automated parts cleaning methods are:
These are cabinet-style washers that operate like a dishwasher where the parts are cleaned by being hit with high-pressure spray from various angles while the parts rotate on some type of turntable to ensure a complete cleaning. Typically, heated, aqueous-based chemistries are used.
Aqueous-based solvents are water-based solutions and can be composed of detergents, alkaline chemicals, microbes or any combination of these. Instead of dissolving grease or solids, aqueous-based solvents use heat, agitation, soap action and time to break dirt into smaller particles.
High-pressure spray parts washers are “great for the harder-to-get-off stuff that may be baked onto a part, as well as the heavier greases and oils, and are most effective for cleaning exterior surfaces,” Spaziani says.
“One big advantage here is that these units are typically very customizable and you can add conveyor systems, drying cycles, rinse cycles, etc.”
With these vat-style units, parts are immersed into a cleaning bath and hit with ultrasonic energy to produce high energy bubbles that vibrate contaminants off surfaces for a high level of clean. This is the preferred method for cleaning blind holes and crevices, and smaller parts.
“While a bit more expensive than other technologies, this method is chosen typically because the process, the ‘clean’ requirements or the design of the parts to be cleaned demand it,” says Spaziani.
With this type of parts cleaner, also a vat-style, the parts are immersed into the bath and are either agitated up and down or side-to-side on a tray, or hit with high-pressure spray under immersion or a combination of both.
Immersion agitation is “ideal” for both exterior and interior cleaning that spray alone and ultrasonics can’t reach, and for removing contaminants that require soaking to break down effectively for removal.