The MART Corporation

| Home | Contact |

MART Articles

Articles - How to Select a Washing Machine



PRESENTED at CleanTech 2000 in Las Vegas on June 5, 2000
by Gary Minkin, MART President

There are such wonderful opportunities and benefits that are possible with the washing process but Industry most often does not avail itself of these benefits and opportunities. There are two reasons for this. First is that most people believe that the washing process is severely limited and that moderately or extremely difficult cleaning jobs cannot be handled with washing. The result is that people often reject washing as the solution to a cleaning problem without investigation, opting for other methods and technologies.

The second reason why industry often misses the mark is that the selection and purchase of a washing system is usually regarded as a commodity issue – simple and straightforward. I will share three examples with you that demonstrate my point.

The first issue is the limitations of the process. The reality is that incredible results can be consistently achieved with washing. To demonstrate the capability I share with you an extremely difficult cleaning problem that was resolved with washing, the cleaning of jet engine turbine blades.

The blades rotate 30,000 RPM and are in service for up to 22,000 hours before refurbishing. The first stage blades are air-cooled. Small ports allow the air into the blade, a convoluted pathway inside cools the blade, and extremely small holes discharge the air. In service the blades will become impacted with airborne particulate that can set up like rock in the cooling pathways. Discarding a blade that is heavily impacted is not an option because the replacement cost is between $7,000 and $11,000 per blade.

Washing is one method of cleaning the blades. These are the parameters of the wash process for a complete set of 64 or 80 first stage blades: a high concentration of potassium hydroxide in solution, a wash temperature of 300 degrees F, a flow of 6 GPM per blade, an impact pressure of 600 PSI, and a cycling time of two hours per load. Each blade is blasted with hot caustic at 600 PSI impact pressure and 700 gallons of solution, and the blades are clean. The cleaning results are verified by x-ray. Cycling time is between 1-1/2 to 2 minutes per blade.

I know of no competing technology that cleans more thoroughly in one step, at the speed and low operating cost of washing. Note also that the capital investment is lower than competing processes, the equipment is maintained at low cost, and the process is easily maintained as well.

The curious question is this: Why does the process exist at all? The answer is that, of the thousands of engineers and technicians involved in blade reclamation worldwide, one person asked the question: Can jet engine turbine blades be cleaned in a washing system? The event that piqued this gentleman's curiosity was a visit to his son's diesel repair shop where he observed that carbon, scale, paint, sludge and road soil were removed from engine blocks and heads in a washing machine.

I share this example with you in case you are working to resolve a difficult cleaning problem. My suggestion is that, along with other technologies and methods you will investigate, ask the question: Can washing solve this cleaning problem?

Now to the selection and purchase of a washing machine as a commodity. As you will see, clearly it is not. At MART we receive RFQs at the rate of two to four or more each week. I have personally reviewed more than 4,000 RFQs over the past 29 years and bid on about 1,800. In all cases MART had the machine models and could have bid them all, but we were locked out of bidding on the rest. I will explain why in a moment.

First I will share two typical RFQs with you that demonstrate my point. Consider a newly manufactured 8-cylinder EMD engine crankcase that has machining oils, grindings, fines and, possibly, graphite stain. The RFQ will not state what is being cleaned or the dimensions or weight of the part. It will call out a turntable diameter, working height and table load capacity. Next will be a pump callout, most often a 10 horsepower pump that, as we know, is not a pump spec and provides no detail of the performance of the pump system. Nor is it a motor spec. The RFQ may call for stainless steel construction and a fine micron filter. A micron size will be given. And, finally, the RFQ will have one or several details copied from the brochure of a washing machine maker. The RFQ packet might be 2-1/2 inches thick, but the actual machine specs will be less than three pages at most.

My next example is the same engine block coming back for rebuilding. It will have carbon, sludge, paint, scale, road soil and varnish. As with the first example, the RFQ will not state the part being cleaned, or the dimensions or weight of the part. It will give a turntable diameter, working height and table load capacity. Next it will have a pump callout, most likely a 10 horsepower. Mild steel construction and an oil skimmer round out the specs, and it will also have one or more callouts provided by a washer manufacturer.
The first thing we note is that the specs are basically the same for both applications, yet we see how different the cleaning requirements are. The washing machine might meet the requirements of the first application but would definitely be insufficient for the second.

These examples are typical of 95% of the RFQs I have reviewed over time. It's what you would expect when a commodity is being purchased. Price becomes the only issue and only consideration. If a washing machine purchase based on such RFQ is successful, then it is more by good fortune than by design.

I said earlier that MART had received over 4,000 RFQs during the past 29 years and only bid on 1,800 or so. The callouts copied from washer makers' brochures prevented MART from bidding on the rest, even though we had the models and could have met the requirements. Every washer maker has experienced similar frustration at being locked out of the bidding. The buyers lose out as well because they don't get the advantage of reviewing competing bids.

Here are some typical callouts that prevent washer makers from bidding. "Washing machine will have 135 spray nozzles." The spec writer, when asked why, will say that 135 nozzles will ensure complete washing coverage of the wash envelope and that fewer nozzles are not acceptable. MART and many others no-bid the RFQ. "Turntable drive shall consist of a chain wrapped around table with shear pin for overload protection." The spec writer would say that, "When the table drive breaks, it's easier to repair: Bid the specs." Only two or three washer makers use the bicycle chain drive and shear pin, and the rest will no-bid the RFQ. "Washer shall have plastic door seals." Several manufacturers use plastic seals, and the rest have other methods of sealing their doors and, again, are forced to no-bid.

The next problem is that the RFQs always provide some detail on the design of the washing machine, but no information is provided on the application or requirements.

CYCLONE 30 Dual Door Automated Pass Thru
Commodity buying derives none of the benefits from the models, options, accessories and configurations that are available from washer makers. Consider the MART line with 34 pass thru, turntable, clamshell, singleand dual lift door, and tumbler-style models. Each model is available as a batch or fully automated system. Machine sizes range from small systems to washers that will clean a 60 thousand-pound load with a pump system that delivers over three tons of solution a minute at high pressure. MART also offers 104 engineered options so each washing machine can be configured to the specific application and requirements. The average MART machine will have eight options, and some will have 20 options or more. A simple calculation shows that, with 34 models and 104 options and all the mix-and-match possibilities, MART can build over 5 million different washing machines without a single duplication.

Now consider that there are 55 washer makers in America. Each has its own unique product line with models that MART doesn't make, and options MART doesn't offer. The ability of the washer industry to precisely meet a cleaning application and all its requirements, no matter how stringent or unique the requirements might be, is almost a certainty. None of these product lines would exist if washing machines were commodities. Washing machine manufacturers want successful installations that meet the expectations and requirements of the application. No manufacturer, however, can operate in a vacuum. As in industry, here's what we need.

We must know all the parameters and requirements of the application. My recommendation is that you don't call out any design details and, especially, that you don't design a washing machine. The 55 washer makers have already done the designs and engineering, and their models and options are tried and proven. If your RFQs encourage the washer makers to bid, then you will receive excellent responses and the bases for analysis and comparison.

Lets suppose that you generally find a bid response but are not satisfied with a particular component or system they propose. Ask the washer maker if it can offer an alternative or are willing to increase the warranty on this component or system. They might require a nominal charge or may provide the longer warranty at no cost.

Many washer bids are sealed and prevent contact between the manufacturers and buyers. It is important to have dialog between the buyer and the washer makers during the bid process so I suggest that, unless the circumstances are most unusual, you never have sealed bids. No matter how detailed an RFQ might be, an exchange of information would enable the washer makers to be more responsive and also allow the buyer to ask questions of the manufacturers.

What kind of information should be included in the RFQ? First on the list are details of what’s being cleaned. Sizes, shapes and weights are crucial. If the parts are common parts that any washer maker will know, then identifying the parts is sufficient. Otherwise drawings should accompany the RFQ. If the drawings are proprietary, then review the responses and narrow the field down to several washer makers. Require that the remaining manufacturers sign non-disclosure agreements, and furnish drawings to this group with the understanding that the drawings could change their responses and price quotes.

Next the washer makers must know how the parts will be oriented: Hung on hooks? Fixtured? If fixtures will be used, do these fixtures exist and are they already used throughout the plant or will they be designed specifically for the washing machine? If the fixtures exist, then drawings must be included in the RFQ.

Photos of loaded fixtures, empty and with parts loads, are also useful. If fixtures are to be designed, then who will design them and, once designed, who will build them? Because the operating characteristics of washing machines vary so widely, you might want the washer makers to recommend the fixture design.

Note also that, if fixtures will be used, there will always be shaded areas so that some surfaces are not exposed to direct blast from the nozzles. If the manufacturer responds that it can wash a fixture load of parts, then your question in the RFQ is this: How does your process ensure that the shades areas will come clean?

Or will the parts be set directly on the turntable or conveyor, or on pallets? Or in baskets? A basket load of parts is the most difficult load to wash because each basket is random loaded and the parts are nested. Each basket load is unique. It will have blind surfaces and hidden recesses that are not accessible to direct spray from the manifold. How will the washer machine clean to the heart of the load? That is the question for the RFQ: Describe the process.

A related issue is material handling. If the plant has material handling methods that are generally used throughout the plant, then it can be a requirement that the washing machine utilize the same material handling process whether conveyor, overhead, fork truck or other method. Identify the method and ask how the manufacturer will incorporate this method in its process.

Next, washer makers must know the substrates. Iron or steel? Note that iron and steel wash differently. Or aluminum or zinc die cast? Titanium? Bronze or brass? How about plastic? And if plastic, will it be high temp plastic or not. It makes a big difference because plastics clean differently. If you wash a standard plastic in a high temperature process you will end up with a lot of very clean, very warped plastic.

The next issue is the soils to be removed. It is not enough to identify the soils generally, such as carbon, grease and hydrocarbons because the characteristics are different and so is soil removal. Gasoline carbon in an aluminum head requires a different process from the same carbon in an iron head. Diesel carbon is different from gasoline carbon. The question in the RFQ is this: Can you remove this specific carbon and, if so, what is your process? Another type of carbon is the carbon dust embedded in aircraft wheels. The source is the carbon dust is the brake discs when the brakes are applied. Note that aircraft wheels will also have rubber bead and possibly mastic bonded to the rim. The question in the RFQ: Can you remove the carbon dust, bead and mastic and, if so, what is your process?

Grease and oil soils must also be specifically identified. Synthetics, as we know, are standard hydrocarbons with the addition of a clay or synthetic compound. Synthetics remove differently and waste management is a different issue as well. The question: Can you remove synthetics, and what is your process? And the second question: What is your method of managing the solution and removing the waste?

Washing can remove scale and paint but, by my experience, coatings such as epoxy and polyurethane that are impervious to chemicals, heat and higher impact pressures cannot be removed. When paint or scale removal is a requirement, identify the soil specifically and ask the question: How does your process remove these soils?

Next is throughput. How many loads or piece parts will be washed in an eight-hour shift? This will establish the cycling time per load.

Your RFQ should also address rinsing of the parts and storage once the parts are cleaned, if these are issues. Washer makers can provide rinsing and RP cycles if required.

Now to the most important issue of all, the cleaning standards. You may find it remarkable that no more than 50 of the RFQs I have reviewed over time actually had cleaning standards. I say this is remarkable because cleaned parts are the reason for purchasing a washing machine or any cleaning system. How clean must they be?

At MART, when a customer does not have a cleaning standard, which is most of the time, we suggest a standard that will meet the customer's needs. When the customer agrees with the standard, it becomes a part of the specifications and warranty. We warrant that the washing machine we configure will meet the cleaning standards.

I have an interesting question for you. Who picks the chemical? Your knee jerk reaction is that you do. In fact, it's likely that you already have a chemical in mind for the process. But that's not the answer. The washer maker picks the chemical. It's included in their response, along with the MSDS for the recommended chemical. You may not use it, but their chemical is your fall back. If your own chemical doesn't work, then the chemical they recommend must meet the requirements in the RFQ including the cycling time, cleaning standards and all the rest. One such example that comes to mind is hydrogen embrittlement. When washing such parts as aircraft wheels and landing gear, the question to the washer maker is: Can you clean these parts to our standards without causing hydrogen embrittlement? In order to respond, the washer maker will warrant that the process and chemical it recommends will be safe for this application.

Your RFQ identifies all the parameters and requirements of the application, and the washer maker configures its machine accordingly. It is up to the washer maker to present its process, and the chemical is an integral part of the process. If you don't require them to specify a chemical, then you have let the washer maker off the hook with respect to the results.

This is the reason I am so set against the callouts. Every time you make a callout, whether it's a pump size or table drive method or anything else, you have let the washer off the hook with respect to that component or device. If it doesn't work, you have little recourse because you asked for it.

The RFQ should state all constraints and limitations. If floor space and ceiling height are issues, then these should be listed. If necessary, furnish layout drawings for the installation site. Identify the turntable or conveyor height above floor level, and state whether or not a pit in the floor is acceptable. If services to the machine are limited, such as size and location, these should also be noted. Chemical limitations should be noted as well.

What other issues must be included in the RFQ? The washing system must meet the Federal OSHA and EPA regulations that are in force at the time the machine is ordered.

The warranty policy should also be required with the response. It is not sufficient that the RFQ calls for a one-year warranty because each washer maker will treat the one-year term differently. Some may want to inspect failed parts before supplying replacements. Consider the cleaning time lost while waiting for replacement parts. Other washer makers send its customers back to the manufacturer of the components. Still others might make the one-year warranty so conditional that you will never get satisfaction on a warranty claim.

You might also require a warranty that is longer than one year, or a warranty based on operating hours rather than years of service. In this event you should call out that an hour meter be supplied with the washing machine. An hour meter is an excellent idea anyway because you can set a maintenance schedule based on operating hours.

Assuming that the washing machine is not a custom system, the RFQ should also require that an operating manual be included with the reply. An operating manual cuts through the sales rhetoric and explains, in simple language, how the machine operates, the maintenance required, and the results you can reasonably expect. As part of your review you should compare manuals. This also tells you the manufacturer's knowledge with respect to your industry and requirements, and the cleaning process.

The final document you should require with the response is a Performance Warranty. This simply states that, if the washing machine does not meet the requirements of the RFQ when operated according to the operating manual, it can be returned to the manufacturer without recourse to your company. A Performance Warranty - sometimes called a merchantability agreement - is implied with everything that we buy today, whether it's a fast food hamburger or a computer or a jet plane. The agreement formalizes and makes explicit what is already implied. The manufacturer, by signing the warranty, guarantees that its machine will meet all the parameters of the process and application.

I have covered much ground in our brief 40 minutes, and will be pleased to answer your questions now or by phone, fax or e-mail as they arise.

Also note that MART has been furnishing the private sector and government agencies with generic-type bid specs for washing machines for the past 15 years. These bids do not favor MART or any other washer maker, but rather the cleaning process itself, and all the elements that affect the installation. The bids we provide are complete and cover all the details I have discussed this morning. MART will be pleased to provide such bid specifications or assist you in developing your own. This service is free and I encourage you to take advantage of it. Let MART help you maximize the benefits of your washing machine purchases .. every time.

Thank you.

Industry Leader in Aqueous Parts Washer Technology

©2003 The MART Corporation. All Rights Reserved.

| About MART® | Industries & Application | Products | Technology | Owner Services | Articles | Contact |