Company Upgrades Blackening System To Improve Coupling Finish Quality

Product recognition in the marketplace is important to most companies. For Lovejoy Inc. (Downers Grove, Illinois), a manufacturer of power transmission couplings including curved jaw, elastomeric, rubber-in-shear, gear, grid, torsional and specialty models, a blackened hub and vivid orange label serve as its calling card in the industry.

The company recently implemented a series of changes to its blackening lines, which not only improved coupling quality and its recognizable appearance, but also saved the company thousands of dollars. The changes are helping Lovejoy achieve ISO 9001 compliance.

Ed Zdanowski, the Lovejoy quality manager who coordinated the blackening system evaluation and upgrade, reports that the new process finishes parts in half the time of the old method with much better quality finishes.

Lovejoy's blackening line was originally installed in Downers Grove in the early 1980s and utilized a heated (285° F) black oxide process. The system initially did the job, but as production volume grew and pollution regulation became more stringent in the 90s, it was evident that quality and pollution problems were increasing.

Mr. Zdanowski and his team identified several issues that needed attention. The process was increasingly difficult to control as production volume increased. Chemical solutions drifted out of balance frequently and had to be dumped. New solutions had to be mixed and re-heated to maintain correct blackening conditions, causing expensive unscheduled downtime and production delays. Finishes were not up to the quality level Lovejoy wanted, and finish consistency was difficult to maintain. Customers were demanding higher quality and Lovejoy saw that it had to deliver that quality. The process line produced an increasingly large volume of sludge and waste that had to be drummed up and sent outside for expensive waste treatment.

"In 1993, we hit an all time high, generating 126 drums of hazardous flammable and corrosive wastes from the black oxide line. Disposal costs that year exceeded $28,000," reported Mr. Zdanowski, "which was excessive for our operation." About the time Lovejoy evaluated its hot oxide line, the company was also preparing for ISO 9001 certification. Together, these factors mandated a better finishing process, and Mr. Zdanowski, who wanted to keep the finishing process in-house, was the designated team leader for getting it done.

When Mr. Zdanowski was asked to describe the ideal finish and process, he had four primary criteria: (1) a high quality, clean black finish; (2) corrosion resistance from creation to service; (3) the process itself should be safe and easy to operate, with simple bath control techniques; (4) the process should not pose an environmental hazard, and it must be easy to justify to Lovejoy's neighbors and board of directors.

After investigating several blackening options, Mr. Zdanowski's team chose the Birchwood Casey (Eden Prairie, Minnesota) Presto Black system for its Downers Grove facility. Lovejoy sent sample parts to Birchwood Casey's labs for development of the optimum process parameters. When the parts were returned, Lovejoy found the black finish to be very satisfactory in terms of appearance, corrosion resistance, thickness and uniformity.

Mr. Zdanowski then planned a production scale test to further analyze costs and performance. The new cold blackening process was installed right next to the old line and a two-week test was run without dismantling any of the existing equipment. For this test, Birchwood Casey provided the required process chemicals and a factory technician to train the operators. These tests proved conclusively that finish quality was higher and operating costs were lower in the Presto Black process. Mr. Zdanowski then decided to go forward with the full-scale retrofit of the existing tank line utilizing the new cold blackening process.

"We were on our way with the new system in a very short time with the help of Birchwood Casey technical personnel. Once installed, results were even better than in the production trials," Mr. Zdanowski stated. "One of the best features of the process was that the solutions operate as permanent baths with no dumping required. The bulk of the hazardous waste collection and disposal was eliminated. Instead of 126 drums of waste a year costing $28,000 to dispose of, we now generate only four drums of spent filter tubes annually, which cost just $700."

Following the success at the Downers Grove plant, Lovejoy installed a second process line in its South Haven, Michigan, facility. Both use Birchwood Casey's customer assistance program, whereby process solutions and rinse water samples are regularly sent in for chemical analysis at no charge. This ensures ongoing chemical balance for top quality and economical part finishing for both operations while meeting environmental regulatory standards. "Not only are we saving on disposal costs," says Mr. Zdanowski, "we're able to gain important EPA regulatory relief by qualifying as a small quantity generator. Needless to say, we're very pleased with the results because our part productivity has been doubled and our quality standards met while saving money doing it."