Increasing Cleaner Efficiency

MetoKote Corporation is head-quartered in Lima, Ohio. It also has a number of production plants in the Midwest and South that offer electrocoating and powder coating, as well as other coatings. Cathodic electrodeposition is a MetoKote specialty. Electrocoating and powder coating are done at the company's Sheffield Village, Ohio, plant.

Continual engineering of fixturing has yielded numerous methods of racking customer parts. Using square transfer and monorail equipment, the company can coat almost any size, shape and volume of parts to most specifications.

The company's pretreatment process features many options. However, MetoKote knew it had picked a winner shortly after installing a coalescing oil separator on one of its specialty pretreatment coating lines at the Sheffield Village plant.

After two months, reports indicated the coalescer unit was cutting cleaning time in half. It also saved the company more than $4,000 over the previous system. Significant improvements in waste treatment and environmental processes were other benefits.

"We are estimating that it will save us well in excess of $10,000 annually, figuring in the environmental factors as well as the basic operational ones," said Mary Ellen Wise, MetoKote's quality systems manager. "The system has paid for itself in six to eight months."

Designed to extend cleaner bath life by removing nonsoluble oils from process cleaners, the coalescing unit has significantly reduced the number of times the cleaning tank has to be dumped. "We are looking at possibly once a year for dumping the tank with the coalescer," Ms. Wise said. "Before, we were dumping every six to eight weeks."

The Sheffield Village facility is a quality paint finishing shop running both electrodeposition and powder coating operations. Various size parts used in automotive and appliance applications, as well as general industrial and commercial, are processed at the facility. The five-year old, 105,000 sq ft plant coats approximately 60 million pieces annually. Typical turnaround time is less than three days. When necessary, jobs can be turned around in an eight-hr shift.

"We are running state-of-the-art systems," MetoKote plant manager Robert Stoll pointed out. "In addition to the cleaning line, we recently installed a monorail electrocoat line. Our new powder coat line will include pretreatment and cleaning capability. That stage is presently handled offline," Mr. Stoll said.

Coalescer streamlines cleaning process. The Parker Amchem three gpm coalescing oil separator has been installed on a line dedicated to pipe product used in industrial, commercial and residential gas riser applications. "The pipe comes to us on a daily basis coated in grease, oil and other materials. When the pipe leaves, it must pass a stringent series of performance tests. So getting the pipe clean is crucial," Ms. Wise emphasized.

The coalescer unit is installed on a Parco® 2076 alkaline cleaner bath. It is used with oleophilic coalescing media. The unit settles suspended particles and separates and removes a high percentage of dispersed oils contained in the process cleaners.

In the cleaning process, the pipe is put through selective tanks with the full bath cycle consuming approximately 30 min. Initially it goes through the cleaner and then into a rinse. This is followed by an acid bath for rust/scale removal and a third rinse. The next step involves an iron phosphate bath followed by another rinse. The final stages include a chrome sealer followed by two rinses.

After phosphating, the pipe is blasted to retain the iron phosphate coating on the inside diameter and to make certain all of the iron phosphate is removed from the outside diameter.

"The blasting provides a pattern for the powder to adhere," Ms. Wise said. "This is a highperformance line. Since the pipe is used as gas risers, it has to withstand 1,000 to 2,000 hours of salt spray and some nasty environmental testing."

"Just consider how crucial the cleaning process is to this industry," Mr. Stoll commented. "If you do not clean it, you cannot coat it. It is that simple. Therefore anything that we can do to improve the process and increase our cleaning efficiency is a big plus for us."

In addition to time and labor savings, the oil coalescing separator has simplified the cleaning process for MetoKote and enabled the company to drastically reduce waste handling procedures.

"We have had some major problems with oils and cleaning parts that arrive with various solvents," Mr. Stoll noted. "One of the nice things about the pipe cleaning line, since installing the coalescing unit we can clean virtually any substrate just by turning different tanks on and off. It has greatly improved our efficiency, and reduced our downtime all of which contributes to our bottom line savings."

Several factors help cut costs. "Lower costs are a combination of how much we save in chemicals, less tank dumping, and the costs to putting the materials through our wastewater treatment facility," Ms. Wise explained. "Labor savings are another important factor, as well as reducing any potential hazards for employees."

After approximately eight to nine months, MetoKote dumped the tank for the first time since installing the coalescing oil separator. "We estimate that this is the dumping frequency we will maintain," Ms. Wise pointed out.

Before the coalescer unit was put into use, rapid soil buildup in the cleaner degraded cleaning performance and often required a second bath, adding processing steps. According to Ms. Wise, at a certain point, the cleaner would stop performing, necessitating a bath dump and generating a new bath.

To monitor the cleaning bath, MetoKote ran Babcock1 tests to determine need for dumping and installing a new bath. Prior to putting in the coalescer unit, when oil content reached four pct, which occurred about every six to eight weeks, the bath had to be changed. Since turning on the coalescer, tests have shown the bath retaining a constant two pct level. "That is what the oil coalescer will do," Chris Hollingsworth, MetoKote's laboratory technician said. "It will not pull 100 pct, but it pulls enough oil out that it allows you to operate at an optimum level without overdoing it."

Mr. Hollingsworth worked closely with the supplier to monitor the coalescer operation. "We checked oil split results, ounces per gallon, chemical additions, operating time, amount of oil collected and cleaning effectiveness," he explained.

Simplified maintenance. "Maintenance of the coalescing oil separator is limited to removing and cleaning the coalescing media and removing accumulated sediment," Ms. Wise emphasized. "With the coalescer, we are not pushing limits anymore in the cleaning process. We are actually cleaning better," she added.

"Cleaning times," said Bob Rogers, "have been cut by more than half. With the old system, the cleaning process took more than 25 minutes. Presently it runs between eight to 10 minutes. I pulled a cage with oleophilic materials while I was a line operator and pressure washed it, which took 20 minutes. Removing contaminants would take anywhere between two and three hours."

"This also simplifies our wastewater treatment process," Mr. Rogers pointed out. "It is hard and expensive to treat the cleaner in the wastewater. But the coalescer is hooked up to our 2,700 gal tank, which makes it very cost effective."

Environmental impact. "There has been a real reduction in environmental risks and a real improvement in quality," Mr. Rogers said. "We had a carryout problem before putting the coalescer online. Oil dragging down the line resulted in problems in other stages of the system. That is no longer a concern."