Technology with a can-do attitude: ceramic bearings let seam roller tooling performs better. (Technology Update).
From the viewpoint of the can maker, canner and end manufacturer, searching for ways to reduce manufacturing costs and improving production quality have always been high-priority goals. With the introduction of ceramic bearings into the manufacturing equation, there are distinct possibilities of moving further along the path toward achieving these goals.
As the leading independent U.S. manufacturer of can-closing parts, TMI, headquartered in Santa Clara, CA, has produced seamer tooling for the canning industry on a worldwide basis for more than 35 years. Devoted exclusively to the production of replacement parts and related components for the food and beverage industry. TMI's state-of-the art computer-controlled machinery turns out precision ground parts, holding tolerances of lot of 1/10th 1/1000th of an inch. Using more than 60,000 pounds of stainless steel per year, seaming rolls and chucks are manufactured for a variety of can-closing machines from vintage models to today's ultra-modern seamers.
Featuring CERBEC ceramic balls (silicon nitride) manufactured by Saint-Gobain Advanced Ceramics, East Granby, CT, TMI's ceramic bearings have proven to last up to five times longer than traditional bearings because of their lighter weight, smoother surface, lower vibration level and reduced operating temperatures. Because of the novel properties of CERBEC ceramic balls, TMI's ceramic bearings routinely run at considerably lower operating temperatures, the company reports. At the same time, running speeds can be increased by as much as 40 percent to 50 percent while using less lubricant. This reduced lubricant usage translates to additional cost savings.
A common experience is that standard steel bearings develop wear particles over time. Consequently, adhesive wear build-up eventually produces worn contact surfaces. Wear particles generated by adhesive wear are not present in ceramic balls because of the unique properties of silicon nitride, according to Saint-Gobain Advanced Ceramics. Corrosion-resistance, also a feature of ceramic bearings, is a definite plus over steel bearings, which have the capacity to corrode over time. When considering extending bearing life in a seaming roll by changing to ceramic material, it is important to take steps to extend the life of the seaming roll itself so that all elements have approximately the same wear life. One way to do so is to utilize powdered mold steel that is highly corrosion-resistant rather than stainless steel or D-2 tool steel. Secondly, the application of a surface coating, such as titanium nitride (TiN), further extends the life of the seaming roll by increasing lubricity and reducing friction and roll w ear. When all three elements are present--ceramic bearings, high-performance steel and TiN coating--the end user benefits.
Using the technology
The beverage industry has been the first of the canners to embrace the use of ceramic bearings in seaming rolls manufactured with long wearing steel that has been TiN-coated. Because of the dependence on high-speed canners in the beverage sector, which typically close 1,200 to 2,000 cans per minute, ceramic bearings have shown to be effective. It is in the food industry, where low-speed seamers are employed (250 to 600 cans per minute), that the use of ceramic bearings has been slower in gaining acceptance.
Jeff Hess, maintenance supervisor at American Nutrition Inc., a pet food manufacturer headquartered in Ogden, UT, began using ceramic bearing seaming rolls supplied by TMI. Hess comments: "We've been looking for ways to make our tooling last longer on our Angelus 62H seamers. A few years back, our tooling supplier suggested we use titanium nitride coating on our rolls and we've been happy with the improved performance. Then we began using ceramic bearings several months ago and so far have found that the ceramic bearings have lasted much longer than the standard steel bearings. We're still conducting tests to see how much life we can get out of the ceramic bearings."
As with most tooling, the wear life is dependent on a few factors: the type of product canned and the amount of maintenance performed. When foods are highly acidic, tooling tends to wear faster than when low-pH-content food products are canned. The caustic nature of high-pH foods breaks down the surface of the tooling prematurely. The type of maintenance performed during canning can also directly affect the longevity of seaming rolls and chucks. If tooling is not lubricated often enough, then premature wear will take place. If rolls are not installed properly and the bearings are not shimmed correctly, early wear will occur as well.
Citing another productivity example, Phoenix Packaging, based in Canton, OH, is a can end manufacturer specializing in easy-open ends for the food and pharmaceutical industries. Since the company's inception in 1993, Phoenix Packaging has focused solely on designing and developing easy-open ends. Jerry Evans, vice president, is currently putting ceramic bearings to the test with a large-scale food canner in the U.S. "There is a pioneering effort toward gage reduction to lower the cost of easy-open ends in the food industry," explains Evans. "We're interested in using ceramic bearing seaming rolls to help our customers minimize cover wrinkle amplitude and reduce scuffing."
Downgaging the weight of both cans and ends presents the challenge of obtaining a smooth seam without scuffing and wrinkles. Jerry Evans continues: "With thinner ends and thinner can body-stock, complications crop up. A lighter end stock tends to form a high amplitude cover wrinkle during the first operation, where the cover wrinkle can become tall and sharp. It's difficult to iron out that type of wrinkle during the second operation of a double seaming process."
At slow speeds, a seaming roll can stop rotating during the brief moment after one can is seamed and just before the next can comes in contact with the roll. When that happens, the stalling action of the roll can cause friction as the next can comes in contact with the seaming roll. That friction build-up causes heat and can contribute to the deterioration of both the roll and chuck.
"We believe," Evans says, "that cover wrinkle amplitude can be minimized because the seaming roll is less likely to stall with ceramic bearings. The reduced friction contributes to less heat build-up, which adds to the life of the seaming rolls and chucks. Overall, the ceramic bearings enhance the quality of the first operation seam and help reduce scuffing and marring as well."
Over the past several years, seamer tooling technology has been continually moving toward improving the wear life of can closing tools. Along with longer-wearing powdered mold steel and high-tech surface coatings, ceramic bearings may very well be the next important element in increasing the longevity of seamer replacement tools. Saint-Gobain Advanced Ceramics, East Granby, CT, http://www.OneRS.net/108tp-391 or circle 391.
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|Publication:||Tooling & Production|
|Date:||Aug 1, 2001|
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