April 2009 / Volume 61 / Issue 4|
By Bill Kennedy
| Quality Mould Inc., a maker of molds for glass products such as lamps and headlights, thrives by leveraging its skills and using advanced technology.
U.S. moldmaking has been hit hard by overseas competition. Makers of molds for glass products face added pressure because alternate materials—mostly plastics—are replacing many glass applications.
Quality Mould Inc., one of a handful of independent glass mold shops remaining in the U.S., machines molds for pressed-glass products. The shop combines traditional craftsmanship with CNC machining and CAM technology that set its products apart from those of overseas competitors. Quality Mould is also leveraging its longtime skills to diversify its customer base.
Founded in 1983 in Greensburg, Pa., and now located in Latrobe, Pa., Quality Mould has produced molds for pressed-glass products ranging from
Courtesy of B. Kennedy
Changes in material application have affected the glassmaking business. Bruce Stephens, president of glassware manufacturer Chromaglass Inc., Delmont, Pa., and a Quality Mould customer, said, “Obviously foreign competition has hurt,” but added that alternate materials have also had a significant effect. Chromaglass manufactures clear and colored heat-resistant borosilicate glass.
Stephens cited the move to light emitting diodes that has increased the use of plastic lenses. “LEDs don’t
Quality Mould takes full advantage of that market. For example, the company makes glass molds for highly contoured, precision glass lenses for landing lights and other applications on commercial and military aircraft. Tough, long-wearing molds for large-volume applications, such as headlight and spotlight lenses, are another specialty, as are molds for large specialty glass products.
“We probably do more big stuff than little stuff,” said Quality Mould President D.J. Danko. “Everybody is sending us huge parts to cut, because we can. We just made a mold for a 24 "-dia. lens for lights on a movie set.”
The shop recently purchased two machines to cut larger workpieces, a Mazak VTC 300 vertical machining center with X-, Y- and Z-axis travels of 65 ", 30 " and 26 ", respectively, and a Doosan Puma VT900 vertical turning center for parts up to 40 " in diameter. Many mold components, such as those for lighting applications, are round and involve turning. “Then, if it gets holes or slots, it will go into the mill,” Danko said.Reverse Engineering
Danko said one of Quality Mould’s strengths is reverse engineering. “We can take a piece of glass, reverse engineer it, design a mold and copy it,” he said.
For smaller pieces, the shop often uses digital scanning to create 3-D electronic files. Those files are exported to a SURFCAM CAD/CAM system to create mold machining programs. For larger complex parts, however, Quality Mould often collects dimensions by physically measuring plaster molds of the part.
One example is the process for a 28 "-dia., 8 "-tall mold for a glass light shade.The first step was making a plaster cast of the inside of the shade and cutting the cast in half vertically through the center. The resulting half-dome was centered on a large piece of paper. Scribing around the periphery, technicians measured and recorded the radii, angles and diameter of what would be the mold’s plunger. Smaller casts also were made of the major details and measured.
“We can tell the programmer that a scallop is so deep, so wide, a certain height and a certain radius,” said Barry Beveridge, vice president. “We can get the dimensions off a piece of paper as close as 0.005 " to the original piece.”
A CAD/CAM programmer created a 3-D file of the part and generated machine code to cut the plunger. By measuring the thickness of the glass in the original shade, the shop calculated the dimensions of the mold cavity and translated them into a CAM program.
For other reverse engineering jobs, the shop makes a plaster mold of a part, casts a positive replica of the item, then casts a mold master from the replica in hard silicon-carbide-reinforced plastic. The plastic master mold is then traced with a vintage Deckel pantograph duplicating machine. The Deckel has two heads connected in parallel, one with a tracing probe and one with a milling spindle. As the operator traces the hard plastic mold master with the probe, the machine spindle, equipped with the appropriate cutting tool, cuts the metal mold that will form the glass product.Nearness Counts
Beveridge said one of Quality Mould’s clear advantages over offshore competition is proximity. “We work directly with the customer,” he said. “We know exactly what is going to withstand the heat, what mold thicknesses are appropriate and what is going to press the best. If the customer makes changes in the middle of the process, we can do that immediately.” In many cases, Quality Mould keeps semifinished molds in inventory and can finish them to customer specifications and deliver in a few days.
Hugh Reed, director of technical services at Kopp Glass, Pittsburgh, said the glassmaker shares many of Quality Mould’s challenges and its approach to customer service. Kopp Glass focuses on low-volume, specialty glass products and colored glass products, serving a variety of markets from aerospace to industrial lighting applications and utilizing a wide range of colored and technical glass options. Kopp manufactures most of its molds in-house, “but for molds larger than our equipment can handle or for expedited delivery requests, we use Quality Mould,” he said.
Reed said interaction with customers throughout the design and glassmaking process is crucial. “We prefer customer involvement as early as possible in the design stage of the project. When possible, we can tweak the shape, the thicknesses, the tolerances or some of the design characteristics to give them the best price possible. There are many features of a glass lens that can be slightly modified to improve the glass flow and the forming process in general,” Reed said. “Preferably, a customer supplies us with a basic 2-D drawing and an IGES file with a preliminary concept. Then we tweak it a bit and work with them to make it a manufacturable piece,” he said. The staff at Quality Mould, he added, “understands what we are looking for and can help work out the details.”
Danko reported that an unintended result of the offshoring trend is growing demand for repair and remanufacturing of faulty foreign molds. He said his shop generally “doesn’t like to touch” such remedial work, but will handle it for a premium price. For example, Quality Mould attempted to rework a set of inaccurate molds that a glassmaker outsourced to an Asian supplier, supposedly to save $10,000. “We went to recut them and I checked the hardness; they weren’t heat treated,” Danko said. “They were supposed to be Inconel; we had them analyzed and they weren’t even close to Inconel. Thirty thousand dollars worth of molds went into scrap.”
Cost pressures drive Quality Mould to continuously boost productivity and minimize labor costs. The shop has 10 CNC mills and seven CNC lathes run by four operators on the first shift and three on the second shift. Operators are cross-trained to set up, program and run multiple machines and handle initial part checking. The shop typically programs parts off machine. “We download the programs to the machines through an Ethernet,” said Danko. “That way, when machining is done, the operators have the program, the tools and the fixtures ready. It speeds throughput.”New Opportunities
Fundamental changes in Quality Mould’s business, such as the declining use of glass, can’t be overcome by excellent customer service or productivity initiatives. As a result, the shop is finding new ways to apply its equipment and well-developed skills.
Quality Mould recently started handling overflow of general machining for another shop that makes military parts. A typical job is a ¾ "×53 "×17 " A-656 steel axle plate for a Humvee that involved drilling and tapping 12 holes and machining a curved slot and a large hole. “The military part work is actually a step down for us,” Danko said. “It is easy, because we are a multiaxis shop doing a lot of design work.” The key to handling contract work, he said, is quickly developing a process within a target price.
Its enhanced ability to machine large parts also helps Quality Mould handle big jobs more efficiently. In processing large drive gears for Caterpillar Tractor Co., the shop’s new large machines boost productivity. Before acquiring the Doosan VTL, Danko said, “We were machining the gears horizontally and only grabbing about 0.800 " of the part. We couldn’t rip into it; it might throw the piece out of the machine. On a vertical lathe the weight of the part helps hold it down. More secure workholding enabled the shop to increase cutting parameters. “We pretty much cut the cycle time in half on the drive gears,” Danko said.
Finish machining and fine polishing are key moldmaking skills, and Quality Mould has applied those capabilities in a new way: drilling and polishing high-end automotive accessory wheels. Danko said the wheel makers “supplied us with a forged blank and we machined the different patterns.” The wheels were then mounted on a chuck, sanded with progressively finer sandpaper grits and polished to a mirror finish with a buffing compound.Work Is Where You Find It
Expanding the shop’s customer base is a constant effort, said Danko. “We get hooked up with a lot of people through word of mouth; cutting tool salesmen and other suppliers go out and really push for us. They tell other manufacturers that our shop can do complex parts and offer a lot of throughput.” Opportunities the shop is exploring include making power generation, mining and railway parts. Through a contact met at a military manufacturing trade show, the shop landed a contract to make parts for revamped naval vessels.
Manufacturing success is not determined by simply making good parts. Quality Mould is a prime example of a shop responding on a variety of fronts to survive and thrive in a global economic and technological landscape. CTEAbout the Author: Bill Kennedy, based in Latrobe, Pa., is contributing editor for Cutting Tool Engineering. Contact him at (724) 537-6182 or by e-mail at email@example.com.
The pressed-glass process: fast, precise and inexpensive
Carved by Hand
skill is hand carving of mold masters. Working from a 2-D sketch or a customer’s idea, Quality Mould’s Barry Beveridge hand carves a 3-D item from a plaster blank. A master mold is then made of the item, and that master is then traced to machine the actual mold. Beveridge said he began carving as a child, apprenticed in a mold shop hand carving bottle molds then was hired by a mold shop (his former employer) to work in the engineering department carving models. About 4 years ago, he said, demand for hand carving “came to a screeching halt,” mostly due to the increasing accuracy of laser scanning and CAD programs. “Every once in a while, we still get jobs where I have to do some model work,” he said, adding that it remains a satisfying and productive pursuit.
Kopp Glass Inc.
Quality Mould Inc.
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