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Grinding's future is something to behold; options, new products light the way.

The future of grinding remains promising. Though most market studies label abrasive technology as a mature part of the manufacturing industry, it's far from a static business. In fact, the range of abrasive methods is still growing. Finishing applications, for example, benefit from new micro finishing films that bring new technology to an old art. Still, it's apparent that film won't successfully replace the uses of setup wheels, on which an artisan applies glue and loose abrasives to the periphery of a cotton wheel using age-old methods.

It's going to be a tougher business for smaller companies, says Ken Dixon Jr, Research Abrasives, Wickliffe, OH, commenting of the trend for large companies to limit the number of vendors. Manufacturing's outsourcing and more attention to productivity have already shifted more business to small specialty grinding shops, a trend likely to continue.

"The next five years should reveal incredible growth in grinding technology at the firms one or two notches below the biggest companies. Greater focus upon cycle-time reduction to maximize capacity of equipment should lead to softer, more open-structured and larger grit wheels," Mr Dixon says. At the same time, alternative technologies will continue to challenge traditional grinding processes and spur new product and process developments.

Material evidence

The foundation for grinding's future begins with raw materials. While breakthrough developments like the discovery of CBN are unlikely, manufacturers will continue to refine existing abrasives such as seeded gel grains, creating varieties with characteristics tailored for specific applications. Norton Co's new Targa abrasive grain with its very fine rod-like crystalline structure bonds well to resins, promising better grinding wheels. Also, future grain makers will create and select grain more precisely to make grinding wheels with more consistent composition.

The result is more choices of abrasives grains. Unfortunately, don't expect to see products next week. The introduction of a new bonded product takes time because wheel makers must find suitable bonds and applications.

Many new varieties of abrasives are destined for nonabrasive applications. The same properties that make them useful as abrasives make them valuable for wear-resistant coatings. Most new CBN grain types, for example, are targeted at nonabrasive uses such as polycrystalline materials for machine tool inserts.

Forecasters often predict the demise of conventional abrasives because of the introduction of superabrasives. But trends show the prediction is only partially correct. Uses of superabrasives are limited by economics, practical matters such as ease of handling, and the way that performance is often closely tied to interaction between abrasives and workpiece materials (e.g., the chemical reaction between iron and diamond). Yet consumers will still see more superabrasives especially for high production applications or in machining of new composite materials.

Machines, coolants

With the introduction of new grains, machinists have discovered limitations and weaknesses of older machine tool technology. Benefits from new abrasives in the past have been limited because machines weren't stiff enough, lacked accuracy in wheel and dresser movements, and had poor vibration damping. New machine technology, however, is available to handle the most advanced abrasive materials. Unfortunately, the majority of machines used by industry are still more than 20 years old.

Discussions on the status of the machine tool industry earlier in this decade yielded many programs that brought together government agencies, universities, and private industry. Results, for example, include the new Viking centerless grinder from Cincinnati Milacron, Cincinnati, OH, that joined with the National Center for Manufacturing Sciences and the Oak Ridge National Laboratory to alter the basic machine structure for maximum stiffness. Similarly, Weldon Machine Tool Inc, York, PA, called on the expertise of Alex Slocum of the Massachusetts Institute of Technology (MIT), Cambridge, MA, to reduce vibration in its Gold 130 grinders.

Other changes will be in response to manufacturers' demand for equipment that fits the production strategies for faster production, just-in-time (JIT) scheduling, short production runs, and multipurpose applications. Expect more speedy machines like Edgetek Machine Corp's, Meriden, CT, new superabrasive turning machine, a grinder that replaces hard turning with high speed superabrasive grinding for significantly shorter cycle times, or universal machines like Studer's new grinders promoted with capabilities of "complete machining."

Similarly, new Quickpoint CNC grinding technology from Erwin Junker Machinery, Chickopee, MA, performs multiple machining operations for crankshafts and camshafts in a single clamping. Edgar Obert, vice president, reports its new Jucam and Jucrank machines use a single high-speed CBN wheel just 4mm thick to grind cam profiles and bearing journals in a turning-like operation, with one setup and without the use of mechanical cams.

The crystal ball also shows machines with more sensors, easier-to-use control software, and simulation software that reduces development time and improves troubleshooting. Future controls are illustrated by Robert Hahn's unit for internal grinding that measures forces, anticipates quill deflection, and adjusts wheel positions for greater accuracy and faster cycle times.

"We see a lot of new interest in creepfeed grinding due to the resurgence of the aerospace industry and use of advanced materials," says John Besse of the Norton Co, Worcester, MA. Traditional practices that include turning or milling can't be used with tough new materials, leaving grinding as the only option. Growth in use of creepfeed grinding will be led by the uses of superabrasives, some of which is spearheaded by OEMs who are making smaller machine tools designed for superabrasives.

Gear manufacturing is a niche technology for grinding that can anticipate growth. Consultants in gear technology expect American automobile makers to grind more gears. The push is fueled by successes with CBN and ceramic aluminum oxide and better gear designs made possible with CNC-controlled grinders. The changeover will come because of demand for quieter, longer-lived gears for the automotive industry.

The picture for grinding wheels is clouded somewhat by the growing success of alternate finishing methods, however. New coated abrasives promise equivalent performance at a fraction of the investment costs in machine tools. Companies like Grinding Equipment and Machinery, Youngstown, OH, are combining CNC controls with microfinishing abrasives to make machines for cylindrical and centerless grinding at a fraction of equipment cost. Advances in lapping film promise to reduce the mess-and-cut processing time considerably.

Belts will last longer, give highly consistent finishes, and cut cooler, says John Gagliardi Sr, research specialist for 3M Co, St Paul, MN. "Contrary to the old tradeoff of either materials removal or finish, new 3M coated abrasive products like Multicut or Trizact can provide both." The appearance of more products containing superabrasives will give the cool-cutting characteristics users want. The result is a greatly expanding number of options that calls for a new approach to cost accounting. "The initial cost of an abrasive product is only one small part of the picture. The real 'cost of ownership' for a belt or other product comes from the total picture: environmental issues, worker wages, cost per part, etc."

Others agree. Paul Miekstyn, manager robotic systems, Acme Mfg, Madison Heights, MI, says: "The advent of 3M's new structured abrasive is the most significant finishing product of the decade."

More options

Competition, product development, and new methods mean a lot more choices. Both inside and outside machining operations, abrasive users can expect to see a wider range of options among products and product lines. For handtools, fiber disks, flap disks, and nonwoven products are infiltrating markets previously held by grinding wheels.

Anticipate higher quality products among nonbonded products as manufacturers improve their manufacturing methods. The improvement of nonwoven products during the last decade is a good example of the trend with dramatic increases in quality. Now better suited for metalworking applications, nonwoven products are appearing increasingly among offerings of coated abrasive converters who make them into belts, discs, pads, and other products. Standard Abrasive, Chatsworth, CA, recently installed its own maker of nonwovens (surfacing conditioning abrasives). Weiler Corp, Cresco, PA, changed its name from Weiler Brush Co to reflect a wider range of products that includes nonwoven products.

A worldwide trend toward less expensive, better performing handtools and the introduction of new abrasive products will give other options for surface finishing, according to Glenn Knowlton, manager of Norton Co's new AVOS line of products. These new products have a longer abrasive life, make jobs easier, and demand less from operators because they can see the workpiece through the grinding disc. "With better vision of the work area during grinding, handgrinders can be placed at a lower 5-deg angle, using more of the fiber disc face and allowing the abrasives to work the way they were designed," Mr Knowlton points out.

Jim Elving, product/market manager of metalworking at Norton Co, Troy, NY, anticipates more use of coated abrasive products as consumers become aware of products with Norazan Plus aluminum zirconia, grinding aids, and stronger backing. Users of coarse grits will find products that cut faster and cooler, while those using finer grits will find finishing products that last longer with a uniform finish. These developments give manufacturers the tools for automating operations that have more consistent finishes and are easier to control (less reliance upon the changing skills of operators). The growth industries for coated abrasives include golf clubs and investment casting and aerospace industries that use new harder-to-machine materials. "In changing from stainless steel to titanium, golf club manufacturers need a cool-cutting product that new coated abrasives can provide," Mr Elving explains.

Manufacturing changes

Manufacturing engineers have been seeking more controllable grinding processes, and grinding wheel companies and machine tool-builders are responding. To engineers, the future will give a highly predictable process using software like Cincinnati Milacron's Predicta-Grind. To Frank Savel, TRW Inc, Cleveland, OH, simulation software takes the mystery out of grinding technology and leads the way to processes that are focused on engineering principles. Though current software is not perfect, Mr Savel asserts that continued work combining theoretical and empirical data has so improved its accuracy, that it is useful for standardizing processes, predicting machine maintenance, and many other management applications.

Mr. Elving also says that the shrinking number of staff experienced in abrasives technology means that suppliers of abrasives will be called upon for technical assistance. A trend for large companies to rotate employees among manufacturing operations to increase individual awareness and sense of responsibility will require processes that are easier to learn and will rely less upon operator experience. Trends for companies to outsource grinding operations are shifting the technology from larger manufacturers to small job shops.

Trends to reduce accumulated trauma by repetitive hand motions has led the way to use of more robotics. Experts agree that robotic systems are still far from human capabilities, but development will continue in evolutionary steps toward easier-to-use and faster grinding systems with automation.

The future of grinding technology is continually evolving through development of new products and methods spawned by innovation, international competition, and research. With many new ideas yet to be fully tested by manufacturing, success lies in continued work on specific applications and fundamental studies. Government funding for research will become increasingly sparse and cooperative ventures among companies, research centers, and federal laboratories will be the key to further development. Results will be reserved for companies who participate.
COPYRIGHT 1997 Nelson Publishing
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Copyright 1997 Gale, Cengage Learning. All rights reserved.

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Author:Giese, Ted
Publication:Tooling & Production
Date:Sep 1, 1997
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