Coolant filtering system delivers a clutch performance

One of the world’s premier suppliers of clutch housings and transmission components to the automotive industry, FCC (Indiana) Manufacturing LCC — a subsidiary of the worldwide FCC Company Ltd. (producers of automatic and manual transmission clutch housings, torque converter components, CVT starting clutches, and 4WD clutches) — is well attuned to the pressures of being a world-class, responsive production supplier to automakers. Facing challenges from global competition and ever-demanding customers, the firm and its parent company are continually investigating and implementing improvements to their operations and processes. This helps to optimize just-in-time delivery schedules, extend research and development programs for materials and design, enhance part and component quality, and advance ergonomic issues and efficiency throughout the enterprise.


Such was the case recently when FCC (Indiana) began a review of its manufacturing process for clutch plates at its Portland, Ind., facility. The particular plates in question are first stamped from a mild steel plate, then deburred to knock down the sharp edges, and finally sanded on both sides through a complex system resembling a large belt sander.


According to Gabe Dann, a senior staff engineer at FCC, the sanding process accomplishes three basic steps in the clutch plates’ manufacture. “First, we achieve the necessary plate thickness, held to a very tight tolerance,” Dann says, “and second, the sanding results in the required surface finish for each side of the plates. The third outcome is that the process produces large amounts of sanding sludge. The sludge, a mixture of metal dust from the plates and grit from the sanding belt, permeates the entire process and, if not properly filtered from the coolant, jeopardizes productivity and quality.”


The previously existing system Dann describes consisted of eight sanding machines, each equipped with its own magnetic separator and coolant holding tank. After the dirty, contaminated coolant was passed over the magnetic surface, the so-called “clean” liquid was recycled back into the process. The sludge on the magnetic separator was scraped off and conveyed out to a separate holding container.


“The process left so much sludge in the ‘clean’ tank that each sanding machine had to be shut down twice a week for two hours each time to clean the tanks and associated equipment,” Dann says. “Additionally, the floor in the surrounding area required constant cleaning because of spillage and overflows. Four hours per week per machine of lost production, plus the additional labor hours for cleaning, was unacceptable, not to mention the fact that the job was unpleasant … as were the additional costs.”


The costs Dann refers to include using 48 gallons of coolant formula and upward of 2,800 gallons of water per week, along with the environmentally controlled disposal of 2,400 gallons of contaminated wastewater per week. 


“It was costing us nearly $9,000 per year in labor just to clean the machines, and in excess of $112,000 to properly dispose of the wastewater,” Dann says. “There had to be a better way. We first found the solution at the machine tool show (IMTS) in 2006.”


The 2006 IMTS show is where Mayfran International of Cleveland introduced its VacuFilter coolant cleaning system. The VacuFilter can be used with virtually all types of cutting fluids and lubricants, and is ideally efficient for applications such as grinding, honing, lapping and polishing, gun drilling, and parts washing — and sanding — where filtration of fine particulate from the coolant is required.


The VacuFilter is a compact system that can be installed either on the floor or pit-mounted below the floor, and works with single or multiple machine tools. At the FCC installation, each filter unit is set upon the floor between the two sanding machines it services. In operation, the unit draws contaminated fluids through a disposable paper filter media (optionally available with permanent or a combination of the two) that is supported by a septum plate to capture the solids. A conveyor is used to pull and elevate the media, with its netted sludge and particulate, to a discharge area for disposal. Indexing of the media is actuated automatically via a sensor that monitors the vacuum created by the pump. The pressure differential between the clean coolant side and contaminated side increases due to particulate buildup on the filter media as it reaches a predetermined level. A signal is then sent to the VacuFilter control unit to initiate an index. Importantly, during an index cycle, there is no interruption of coolant flow to the sanding machines.


VacuFilter’s efficient design, using just a single pump, means fewer parts and reduced maintenance, plus long service life and durability. The media is selected based on the application parameters such as fluid type, workpiece materials and process/particulate form. Plus, unlike the magnetic separator units, all particulates – including the non-ferrous media grit – are filtered from the coolant.


Since the installation of the first VacuFilter system and subsequent completion of the final four units, FCC has reduced the cleaning time and downtime of the sanding machines significantly.


“We now spend about two hours cleaning the Mayfran units every three months, instead of twice a week, with virtually no cleaning needed for the sanding systems,” says Dunn. “And the level of coolant cleanliness between the old system and the new VacuFilter systems is remarkable. Because most of the sludge adheres to the paper filter media, handling and disposal is easier. The spent filter material is put in a then-sealed drum and dispatched for proper disposal, making the task of cleaning the machines a much more pleasant job. Also, with the Mayfran units, the surrounding work area and floor space has remained cleaner and safer, with virtually no spillover and less manual handling of the sludge.”


In addition to the labor and times savings, including overtime expenses for emergency servicing, Dann reports that the installation of the VacuFilter systems has resulted in FCC reducing its water usage by as much as 80 percent and its wastewater production by 80 percent. It has seen similar cuts in disposal costs. The site has been able to increase the service life of each sanding belt by eliminating the buildup of sludge on the surface and within the grit of the media, and has slashed the amount of coolant chemicals used by the approximate 80 percent rate.


“With the reduction of sludge and grit in the coolant, and working its way into the moving parts of the machines and wearing on components, we also expect our maintenance and servicing costs to plummet over the long run and with an overall improvement to the condition of the coolant handling system,” he says. “We were also able to eliminate one of our holding tanks previously needed for storing contaminated wastewater, thus freeing up valuable floor space.”


The VacuFilter units are also offered with a series of optional and auxiliary equipment to optimize the performance and efficiency for a variety of application conditions. This list includes a disposable media re-winder that recoils the spent media, and the permanent media option consists of a woven polyester belt. In some applications, it may be beneficial to combine both a permanent belt for normal operation and a finer disposable media style filter for periodic higher level filtering. The VacuFilter can use one in conjunction with the other to achieve needed filtration levels.


Additional options include high-pressure packages, media carrier belt mechanisms, temperature control chiller units, a tramp oil handling package and the supplemental security of adding Mayfran’s AT-Cleaner filtering system for extremely fine particles produced by operations such as polishing.


About Mayfran International
Mayfran is a global manufacturer of conveyor, filtration and separator units for chip and coolant handling in metal cutting and grinding operations, along with scrap handling for stamping operations and for paper and waste recycling industries. For additional information, visit www.mayfran.com.

Two beakers at the FCC (Indiana) facility provide a side-by-side comparison of coolant cleanliness. On the left is nearly translucent coolant processed through the Mayfran VacuFilter system. The right glass contains coolant that was passed over a magnetic separator system. The discoloration demonstrates a large quantity of particulates still in suspension.

At the FCC (Indiana) plant producing automotive clutch plates, spent filter media, with sanding sludge adhering, is discharged from the Mayfran VacuFilter in a clean, continuous film.

Loose sludge being discharged into the bin (and surrounding areas) after processing by previously used magnetic separators.