News - Technical Articles

Lovejoy, Inc. Upgrades Blackening System to Improve Coupling Finish Quality. Reduces Chemical Disposal by 97%.

Product recognition in the marketplace is important to most companies. For Lovejoy brand couplings, a blackened hub and vivid orange label serves as its calling card in the industry.

improved Blackening System

Lovejoy Couplings are available in torque capacities ranging from 1.35 to 54,390,000 in-lbs.

Presto Black process

Many coupling components require blackening and are finished in large quantities using the Birchwood Technologies Presto Black® process.

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 and have gained major EPA (Environmental Protection Agency) regulatory relief.

deep black finish

Ed Zdanowski, Lovejoy Quality Manager, demonstrates the deep black finish with no rub-off produced by the Birchwood Technologies Presto Black process.

Ed Zdanowski, 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 is a world leading manufacturer of power transmission couplings covering the full application range including curved jaw, elastomeric, rubber-in-shear, gear, grid, torsional, plus specialty models such as variable speed, universal joint, sheaves and more. These couplings are used in virtually all industries from agriculture and paper processing to steel mills, machine tools and off-highway applications. Some of these couplings are painted, others electroplated, while a large percentage require blackening for corrosion protection without dimensional change, and to enhance their appearance.

Volume Growth Forces Finishing Line changes

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

Zdanowski and his team identified several issues which needed attention: (1) 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; (2) 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; (3) the process line produced an increasingly large volume of sludge and waste which 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 Zdanowski, "which was excessive for our operation. We took steps in succeeding years to reduce those hazardous materials and disposal costs but it wasn't until we converted the process line to the Presto Black system that we were able to all but eliminate the waste disposal problem and reduce those costs to under a $1000 a year." 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 Zdanowski was the designated team leader for getting it done.

Outsource Versus In-House Finishing

Preparing for Lovejoy's ISO audit, Zdanowski saw the advantages of keeping the finishing process in-house. "Anytime you send parts out for finishing, you give up some of the control over the quality, scheduling and cost of the operation. Lovejoy's leading position in the market demanded that we be a leader in quality control too. Giving up part finishing control by having it done outside wasn't compatible with ISO requirements or with market leadership."

When Zdanowski was asked to describe the ideal finish and process, he had four primary criteria:
  1. The black finish had to be a high quality, deep black color with no signs of red or brown off-colors or salt leaching streaks. The finish had to be a clean black to the touch with no excessive ruboff;
  2. Corrosion resistance was equally important. Even though Lovejoy had no established salt spray specification, finished hubs and parts had to withstand normal handling and warehouse storage through to its dealer network without rusting. After purchase and in service, the finishes were expected to provide adequate corrosion protection and an attractive appearance;
  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. It must be easy to justify to Lovejoy's neighbors and board of directors.

Lab and Production Scale Tests Lead to a Decision for the Cold Blackening Process

After investigating several blackening options, Zdanowski's team chose the Birchwood Technologies Presto Black® system for its Downers Grove facility. The evaluation began when Lovejoy sent sample parts to Birchwood Technologies' labs for development of the optimum process parameters. Once finishing and testing were completed successfully on a lab scale, the parts were returned to Lovejoy for evaluation and testing. The black finish was very satisfactory in terms of appearance, corrosion resistance, thickness and uniformity.

Zdanowski then planned a production scale test to further analyze costs and performance. By utilizing two of Lovejoy's existing process rinse tanks, the new cold blackening process was installed right next to the old line and the test was run without dismantling any of the existing equipment. For this test, Birchwood Technologies provided the required process chemicals and a factory technician to train the operators. The test was run for two weeks, generating a sufficient quantity of finished parts for accurate evaluation. Special attention was given to monitoring bath concentration, process parameters and operator training. These tests proved conclusively that finish quality was higher and operating costs were lower in the Presto Black process.

Zdanowski then decided to go forward with the full-scale retrofit of the existing tank line utilizing the new cold blackening process. Since this choice did not require a significant capital expense, it was carried out immediately.

"We were on our way with the new system in a very short time with the help of Birchwood Technologies technical personnel. Once installed, results were even better than in the production trials," 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.

Lovejoy's new blackening process steps are as follows:
  1. Clean and degrease parts to remove all cutting and fabricating oils using Safe Scrub® ST cleaner at 150°F; 5 minute soak.
  2. Rinse in clean water; 20 seconds at room temperature.
  3. Prepare Surface for blackening using Safe Prep® surface conditioner; 1-1/2 minutes at room temperature.
  4. Rinse in clean water; 20 seconds at room temperature.
  5. Blacken in Presto Black® PBR solution; 2 - 3 minutes at room temperature
  6. Rinse in clean water; 20 seconds at room temperature.
  7. Seal in Dri-Touch® Plus water displacing rust preventative.

Presto Black Finishing Line

Lovejoy's Michigan facility Finishing Line, designed and built by Birchwood Technologies, has seven 100 gallon capacity tanks. The Presto Black® process itself takes just 10 to 15 minutes from start to blackened part.

insured ongoing finish quality

Birchwood Technologies technician, Don Carter, is shown doing a simple bath test to verify solution balance, insuring ongoing finish quality.

Two Lovejoy Plants Utilize Birchwood Technologies' Free On-Going Chemical Analysis

Following success with the retrofit at the Downers Grove plant, Lovejoy installed a second process line in its South Haven, Michigan facility. Both now operate the process lines on a daily basis and take advantage of Birchwood Technologies' 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 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."