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Upgrading a Nickel-Chromium Plating Line, While Operating

Appears in Print as: 'Continuous Improvement at Fleet Design'


Fleet Design, a member of the Imperial Group, has been fabricating and chromium plating exhaust tubing for the heavy truck industry for almost 20 years.

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Fleet Design, a member of the Imperial Group, has been fabricating and chromium plating exhaust tubing for the heavy truck industry for almost 20 years. The beauty and corrosion protection offered by duplex nickel under chrome is the major drawing card for customers such as Peterbilt Motors and Kenworth Trucks which have made chrome products a significant part of their product line-up.

The trucking industry has grown since Fleet started. In 1987, Fleet Design moved its operations from Oakland, CA, to its present site in Gainesville, TX. Throughout this time, the business cycle has gyrated from one extreme to the other, creating drastic swings in product demand and placing tremendous strains on the business. During the past 12 months this trend has accelerated, as the business cycle has rapidly expanded creating demand that has exceeded the company’s plating capacity. As one of the few QS 9000 certified nickel-chromium plating suppliers to the heavy-duty trucking industry, it was imperative that Fleet Design find a way to meet the customer demand and develop a cost-effective, flexible system to meet ongoing demand fluctuations. The trucking industry has grown since Fleet started. In 1987, Fleet Design moved its operations from Oakland, CA, to its present site in Gainesville, TX. Throughout this time, the business cycle has gyrated from one extreme to the other, creating drastic swings in product demand and placing tremendous strains on the business. During the past 12 months this trend has accelerated, as the business cycle has rapidly expanded creating demand that has exceeded the company’s plating capacity. As one of the few QS 9000 certified nickel-chromium plating suppliers to the heavy-duty trucking industry, it was imperative that Fleet Design find a way to meet the customer demand and develop a cost-effective, flexible system to meet ongoing demand fluctuations.

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One constraint to meeting the demand fluctuations was that any system brought on-line would have to be without investment in brick and mortar. The other was that customer delivery times could not be compromised in the short term to create a long-term benefit. With these two constraints, the plant manager and superintendent put together a 6-month plan to overcome the seemingly contradictory demands.

Prior to the upgrades, the plant was plagued with many shortcomings. One shortcoming was the tank sizes and combinations on the plating line. Plating tank depth varied from 42 to 72 inches with tanks ranging from 10 to 12 ft in length. With non-standard tank sizes, there was no way to optimize the rack package. Another shortcoming was the bussing configuration. Most of the rectifiers were only bussed from one leg, thus limiting the amount of amperage that could be fed to the plating cells. Four other capacity limitations were the polishing shop capacity, antiquated electric hoists, an undersized blower and the wastewater treatment system.

With the constraints and the line shortcomings documented, one of the design criteria and key success factors was to create a standard tank size to maximum line density. Since production had to be maintained throughout the project, the time and money to do this task was daunting. To purchase all new tanks was time and cost prohibitive, so an alternative was developed. The alternative was to proceed based on the purchase of two new polypropylene tanks of the correct size, to rebuild three waste treatment tanks into plating tanks, to retrofit three of the existing plating tanks and to modify three pretreatment tanks by extending their height to a standard depth of 72 inches. Tanks were installed in groups of two to three tanks over 3-day weekends spaced about 4 weeks apart. This created a constant hardship on the plant, but production was maintained and capacity grew.

A second success factor was to reduce utility costs through improved electric efficiencies and water reduction. Improved electric efficiency occurred by moving and rebussing all the rectifiers. Before the tank changes, the rectifiers were inefficient because of the long distance to the plating tanks, the fact that only one of the two legs was used and there were numerous spliced connections that were corroded and poorly contacted. After optimizing the buss size and configuration, the rectifiers were able to plate twice the square footage of surface at roughly the same electric use as before.

To impact costs associated with water use, the plant implemented spray rinsing, counterflow rinsing and a rotary evaporator in the nickel and chrome rinse stations. Each of these changes not only helped reduce the amount of water per part consumed, they all had a notable impact on increasing the quality of the plated parts by improving the rinse water quality. Make-up chemicals and wastewater treatment frequency were both reduced using these water-conserving techniques.

One interesting piece of technology in lowering water use was the addition of a chrome reduction system. The chrome reduction unit operates by pumping water from the last rinse tank through a specialized media. This media selectively removes the chrome and discharges the cleaned water to the rinse tank. This unit maintains the final rinse water purity to less than 10 ppm of chrome for virtually no secondary cleaning requirements. These water conservation techniques allowed the plant to process twice the amount of part area at a higher quality level while reducing the load on the wastewater treatment system.

As demand for polishing and plating continued to grow, the electric hoist system became a bottleneck. It was plagued by slow lifting speeds, high downtime, insufficient lifting capacity and too few hoists to meet the workload increase. To counteract this problem, one of the plating specialists from the Fleet Design plant in Portland, TN, where class VIII steel and aluminum bumpers and grilles are polished and plated, stepped in. He designed and built an air hoist system that operated about 30% faster, cost half of what an electric hoist would cost and increased up-time due to the reliability. With the new hoists, the bottleneck operation had been broken and the plant was able to produce at a greater number of rods per day than ever before with only modest capital expenditures. The number of work bars was increased from 80 to more than 135 bars per day for the same number of plating hours.As demand for polishing and plating continued to grow, the electric hoist system became a bottleneck. It was plagued by slow lifting speeds, high downtime, insufficient lifting capacity and too few hoists to meet the workload increase. To counteract this problem, one of the plating specialists from the Fleet Design plant in Portland, TN, where class VIII steel and aluminum bumpers and grilles are polished and plated, stepped in. He designed and built an air hoist system that operated about 30% faster, cost half of what an electric hoist would cost and increased up-time due to the reliability. With the new hoists, the bottleneck operation had been broken and the plant was able to produce at a greater number of rods per day than ever before with only modest capital expenditures. The number of work bars was increased from 80 to more than 135 bars per day for the same number of plating hours.

One place where new technology combined with good manufacturing engineering to overcome a bottleneck was the polishing shop. As customer demand grew and plating output was increased, the polishing shop became overburdened trying to meet the increased demand. Purchasing additional equipment alone would help the backlog, but the lead-time to get more equipment and the human investment to bring new associates up to speed was too long to meet the immediate need at hand. To have a significant impact on demand required not doing more of the same old thing but getting ahead of the learning curve with new technology. Working with 3M’s new Trizact® abrasive technology, the polishing operators were able to eliminate one of the polishing steps. Although the net cost of the Trizact belt is more than a standard belt, the cost is mitigated by eliminating the one step and the higher throughput. Also, there is an increase in belt life. The net result of the change in abrasives was more pieces per hour with virtually the same staff size.

Another significant change that increased output was realized when the hand jacks used to polish the tubes were upgraded. Machine downtime of the hand jacks was a major factor that reduced polishing shop material throughput. The primary cause of this downtime was from bent shafts and spent bearings. Rather than propagate the ongoing downtime from these problems by simply repairing the broken machines, maintenance technicians studied the problem and put together a program to increase the shaft size and install improved bearings whenever a machine went down for one of these causes. Since completing the retrofit program, the hand jack breakdown downtime has been virtually eliminated. A few additional pieces of equipment have been added and more associates hired, but this has been minimal compared to the gains experienced with the new abrasives and better use of current resources.

Results from this conservative approach to creating capacity have been impressive. Part quality has improved with reductions for roughness, pits and stardust and other plating-based rejections going down. Output has jumped from 80 work bars per day with an average of 3.5 pieces per work bar to 180 work bars per day with an average of 6.5 pieces per work bar. Sales have jumped almost 100%, and delivery performance has drastically improved.

Recent market studies and leading producers of fabricated pipe for the heavy-duty truck industry such as Northern Tube and TriCounty Tube indicate the demand for high-quality polished and chrome plated exhaust tubing for the heavy trucking industry will continue to grow. Fleet Design has positioned itself as the leader in the market because of the “I Care” quality policy adopted by all associates as demonstrated by this successful continuous improvement project.

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