Most finishers regard parts cleaning as a process that can be dirty, time-consuming and fraught with headaches (such as dealing with EPA regulations) that ultimately eat up a lot of the time they would rather spend finishing parts.
A new venture called MPW Recovery Technologies is hoping that those headaches are enough to drive finishers through the doors of its facility in Fairborn, Ohio. Recovery Technologies is actually an offshoot of MPW Industrial Services, based out of Hebron, Ohio. Some finishers may already be familiar with the parent company, as it provides a variety of cleaning and plant management services for industries ranging from automotive, power, chemical, petroleum and pulp and paper. It has made a name for itself in the metal finishing industry by offering paint booth cleaning services.
Recovery Technologies is the brainchild of Tom Brooks, the Director of Facility Management and Support Services of MPW Industrial Services. In talking with finishers at the Coating 2001 show in Orlando, Mr. Brooks found that many of them were frustrated by the fact that they were spending too much time and money on cleaning, depriving themselves of the ability to focus on their core competencies.
Mr. Brooks surmised that finishers would welcome the opportunity to do away with the problems associated with parts cleaning. And while the outsourcing of parts for cleaning is not a unique concept, he theorized that by introducing fast turnaround of parts into the mix, MPW could carve a niche for itself in the industry.
Mr. Brooks approached MPW Management about his concept, and the idea was eventually approved. Now, less than two years after the idea was conceived, MPW Recovery Technologies is up-and-running, offering parts cleaning services to finishers in Ohio, Indiana, Michigan and surrounding areas.
In order to meet the expectations of its customers, MPW explored a variety of cleaning and stripping technologies. Factors considered included:
- Cleaning time
- Ability to clean a diverse array ofsubstrates
- Environmental and waste disposal regulations
- Quality of cleaning
- Diversification of service offerings
Turning to Kolene Corporation (Detroit, MI) for assistance, MPW elected to base its operations around two core cleaning technologies. The first is a molten salt bath, used primarily for cleaning racks, fixtures, tooling and other components of paint and powder coatings. The second involves the use of Kolene’s RecoverTM Technology, ideal for use on a wide variety of temperature-sensitive substrates.
Once MPW and Kolene began working together, the relationship between the two companies evolved well beyond the traditional customer/vendor relationship into a strategic partnership. Mark Neiswander, a Sales Representative for Kolene who was instrumental in developing the new association, actively participates in helping the company maximize its use of the Kolene cleaning technologies. Both companies understand that the market is moving towards outsourcing philosophies, and that there is a need for high-end service to an ever-demanding customer base. By cleaning parts more quickly, MPW is able to offer overnight, same shift, or "while you wait" services, depending on customer need and schedule.
Great Balls of Fire!
Many of the parts that come to MPW for cleaning are racks, crossbars, hooks and other accessories. Typically, these parts have little aesthetic value and have been coated hundreds—if not thousands—of times over. MPW decided that the best way to manage the cleaning of these types of parts was with the use of a molten salt bath using Kolene's No. 5 process, which enhances cleanliness and reduces maintenance of parts.
Molten salts are a class of inorganic chemical compounds, heated to a temperature above their melting points to form a working fluid. By combining the building blocks of inorganic salt compounds, a variety of melting points, chemical reactives and degrees of stability can be achieved for a working bath. While molten salt baths are commonly used in organic stripping applications, they also can be used for casting cleaning, engine remanufacturing and descaling.
As parts come into MPW, the are unloaded from a truck, loaded into baskets and weighed. After being weighed, the parts are immersed in the molten salt, where a “cocoon” of solidified salt forms on the cold workload. As the load heats up in the 900F bath, the solid salt remelts and the reaction between the soils and salts begins. Low boiling point/high vapor pressure organics will vaporize and react with the salt; depending on the amount present, some of the vapor will escape from the bath and ignite above its surface (due to the introduction of oxygen). Unignited vapors condense upon cooling and are removed in an air exhaust wet scrubber.
Upon exiting the molten salt bath, parts are immersed in cold water quench and then a hot water rinse. MPW is currently planning to introduce to the line a citric acid bath, which will be used to brighten up select parts. (See our sidebar article, “The Sludge Factor,” for more information about the molten salt bath.)
Recovering Parts… and Profits
The most recent addition to MPW's facility is a cleaning system designed for use on temperature-sensitive substrates that would not be able to withstand the heat and other factors associated with the molten salt bath. These materials include ferrous alloys (including galvanized steels), pot metals, aluminum, magnesium and other substrates. The system’s primary component is Kolene’s Recover™, technology.
RecoverTM is a low temperature cleaning process designed for compatibility with a variety of substrates. Used full-strength in specially designed process equipment, it is heated to between 250F – 350F, depending on the substrate. Once at operating temperature, components are simply immersed into the liquid for stripping and/or cleaning. Cleaning time ranges from several minutes to an hour of more, depending on the substrates and coatings involved. After removal from the Recover™ bath, parts are submitted to a simple water rinse to complete the cleaning process.
Because Recover™ is a gentle cleaning process, MPW considers it an ideal process for reclaiming parts and components, which may have paint blemishes or coating defects.
MPW Plant Manager Ron Klenk also sees the introduction of the Recover™ technology as a move that is consistent with MPW’s focus on quality cleaning with speedy turnaround time. “The one step cleaning process completely removes organic coatings from a variety of substrates, so there’s no need to follow-up the initial cleaning with additional processes to assure proper cleaning. This leads to quicker turnaround and better quality.”
Assuming that MPW Recovery Technologies proves to be a hit with finishers, the company hopes to expand its depot-style cleaning facilities across the United States. According to Mr. Brooks, the prospects for growth are very good. “By combining quick turnaround with a sense of professionalism and our logistical abilities,” he says, “We think we can fill a hole in the market in a lot of places.”
The Sludge Factor
These byproducts settle out of the working bath by gravity and are accumulated in a sludge pan located in the bottom of the saltbath. Because the bath has a high pH, the byproduct will also have a high pH and must be neutralized to lower the pH to an acceptable level for the city of Fairborn to accept at their treatment plant
The sludge pan in the bottom of the salt bath is removed from the salt bath using a hoist. After the excess molten salt drips off, the hot sludge is moved over to a hopper where it is allowed to cool. The sludge pan has a false bottom in it, so when it is set down, the bottom opens, allowing the sludge to go into the hopper. Once emptied, the sludge pan is put back into the bath to be re-used.
The sludge cools in the hopper for about one day. Afterward, a hoist carries the material (now a solid block of sludge) over to a 2,000 gallon dissolving tank. The sludge dissolves in the water and from there it is treated with sulfuric acid to bring the pH down. Once neutralized, the material is filtered through a filter press. The solid material, now a non-hazardous waste, is put into a roll-off dumpster and transported to an appropriate landfill. The water is discharged to the Fairborn water treatment plant.