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IMM's Plant Tour: A multimaterial molding makeover

March 5, 2001

10 Min Read
IMM's Plant Tour: A multimaterial molding makeover

If you ask automotive industry insiders if they've ever heard of a 50-year-old full-service Detroit-area custom molder named Motor City Plastics that specializes in compacts, chances are you will probably get a blank stare. That's because, despite its name, Motor City Plastics Co. Inc. (MCP) does not mold a single automotive part. The "compacts" MCP produces are another name for makeup cases. However, if you ask cosmetics industry insiders about MCP, you still may get a blank stare. 

Motor City Plastics (Dundee, MI) is one of a select few suppliers single-sourced by the top brand names in the demanding $50 billion-plus global market for cosmetics. The company has been molding makeup cases as stock products since the 1950s. When the market began to boom in the 1980s and competition increased, marketers at the cosmetics industry's volume leaders decided it was advantageous to add more decorative pizzazz to packaging in an effort to differentiate their products and to heighten consumer appeal. At that point, MCP diversified into custom molded compacts. It has since equipped itself with the best design and manufacturing technologies it can find to provide agile art-to-part support. 

So why the blank stare? MCP officials admit that manufacturing is something that their cosmetics customers rarely care to acknowledge publicly as being an important part of their sales and marketing efforts. Just look at the advertising for new cosmetics. It is highly unlikely that you will ever see anything about lights-out manufacturing in fully automated multimaterial molding, decorating, and assembly cells. 

Regardless, MCP has achieved its elite status in this exclusive marketplace by using advanced technologies to reduce part costs while producing glamorous, high-quality products. Want to see why the big names in cosmetics are so hush-hush about MCP? Please, powder your nose first, and let's tour. 

Cosmetics Market Snapshot 
"It's a beautiful industry," says Keith R. Ruby, president and ceo at MCP's administrative HQ in Dundee. High-volume personal care packaging is a steady market, he explains, one nearly as recession-resistant as medical. But it's also a market that's almost as technically demanding as medical, and about as price sensitive, as well. 

"Part aesthetics are more important than anything else, although functional performance is critical. Compacts have to close firmly, but they must also be able to be opened without breaking a fingernail," he says. "We have to hold to extremely tight-tolerance specifications, some down to ±.005 to .003 inch." 

Ruby continues, saying, "Time to market also is extremely important, and personal care also is very price sensitive. If a job involves something special that a technical or creative project director wants, the customer will pay for it. But it is still a competitive market. Every job goes out for quotes. It keeps you honest." 

Ruby credits his retired partner, Donald Harkness, for inspiring the company's devotion to advanced design technologies, automation, and equipment standardization. Harkness saw these solutions as the best means of establishing competitive credentials with customers over the long term as volume leaders began demanding more. "We jumped into robots and were 100 percent Reed-Prentice back in the early '80s," recalls Ruby. MCP also had begun using hot runner systems from Husky around that time. 

In early 1996, a customer wanted a compact with a new look—one with a lens in the middle of the cover. The design, however, posed problems. Its cosmetic and functional requirements obviated the possibility to ultrasonically weld the lenses in place. And the idea of molding the lenses in one material on one machine, and molding the covers and bases in another material and machine conjured up images of floor space management, material handling, and scrap problems. 

Kurt D. Kendall worked the region for Husky back then. Kendall had a better idea. To make a long story short, MCP installed its first fully automated multimaterial molding system from Husky in November 1996. Thirty days later it ordered 10 more Husky injection molding systems. By May 1997 all but one of its 18 Reeds had been replaced. 

Of the 14 Huskys it has on the floor today, 12 do the same amount of work all of its Reeds once did. MCP's main manufacturing facility in Dundee has undergone a head-to-toe Husky-style makeover. Kendall says MCP made a 20- to 25-year technological leap in six months. Kendall is now MCP's executive vp and director of operations. 

VITAL STATS

MOTOR CITY PLASTICS CO. INC., DUNDEE, MI

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No. of employees:

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Molding machines:

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Internal moldmaking:



Supplier Partnering 
Upstairs at its HQ is MCP's well-equipped design center, featuring the latest and fastest Unix-driven hardware from Silicon Graphics. MCP runs I-deas Master Series design software. In fact, this forward-thinking company was a beta site for SDRC's I-deas. Flow analysis and FEA software also are used. 

MCP gets involved early in its customers' projects and helps them design parts for manufacturing. It also designs all of its molds. The molds are built by a network of three moldmakers. Most of them come from Basilius Inc. of Toledo, OH. 

In addition to early-on partnering with its CAD/CAM supplier, MCP also was a beta site for Husky's latest S Series presses. "I think we got the first one out of the Husky lab," Ruby says. 

"We have a very good relationship with Husky," adds Kendall. "It is nonexclusive, but we haven't found anything to beat what it has." As an example, he cites the fact that even though the Huskys cycle faster than the old Reeds, the Huskys have reduced mold repairs by about 40 percent. Husky has also helped expand MCP's global sales and marketing reach by exposing the molder to potential customers. The HQ and the manufacturing plant are in Dundee. MCP also operates a small assembly plant in Milan, MI. 

This one-machine, next-generation cell, running a 36-cavity family mold on a press with two injection units, produces just as many finished compacts as the two-machine cell shown below, while consuming just half the floor space.

MCP relies heavily on the use of CAD/CAM/CAE resources to help its customers speed new products to market. It was a beta site for SDRC's I-deas Master Series CAD/CAM software, used here to model the cup handle pictured above.

Family molds dominate at MCP, making this cup handle mold among the exceptions. The company designs molds in-house and outsources tooling from three preferred suppliers.

At its 45,000-sq-ft manufacturing facility MCP operates with minimal human intervention. Standardized cellular molding systems are supported by servo robots and servodriven decorating and assembly auxiliaries, all designed and integrated in-house.



An Automation Supermodel 
MCP's impeccable molding plant is a picture-perfect supermodel of modern cellular manufacturing technology and systems engineering. Fully sprinklered and air-conditioned, it sports banks of bright Halite lights that are suspended from its towering 50-ft-high ceiling. A 40-ton overhead crane spans the entire length of the glistening epoxy-finished floor below. All 14 of the Husky machines operate with the assistance of three-axis Husky servo robots and other standardized automated auxiliaries. Machine utilities are from overhead. 

All of the systems design and integration work, including robot EOATs, is done in-house at MCP. No manual trimming is performed anywhere in the plant. The entire plant hums along with only one maintenance engineer, who also sets molds and oversees the performance of the automated finishing systems. Its internal scrap rate is less than 1 percent. In 1998, MCP shipped 45.4 million compact assemblies, consisting of about 100 million parts. Customer rejects were .0038 percent. In 1999, customer rejects were zero. 

A highlight of the cellular multimolding systems running at MCP is a third-generation cell for compacts built around a 500-ton, two-barreled multimolding machine. The machine runs a sophisticated 36-cavity hot runner family mold for producing snapfit lenses, covers, and bases that are automatically assembled, hot stamped, and packaged in the cell. In another single-machine cell, mirrors are automatically glued into molded compacts with cold-melt and hot-melt adhesives. The lenses, covers, and bases are molded in a six-cavity family mold. Covers are automatically hot stamped at an automated rotary station. 

Yet another cell bears witness to MCP's proficiency in adapting to new manufacturing technologies. Working with gas-assist systems supplier Bauer Plastics Technology Group, MCP developed the cell to mold handles for a new type of plastic cup that reportedly has been well received in the marketplace. MCP cores out the PP handles using gas assist to reduce part weight and cycle times. Then it overmolds them with TPE on another machine in the cell. 

MCP's plant is a work in progress. This two-press cell is designed to manufacture makeup compacts. The compacts consist of snapfit lenses, covers, and bases that are automatically molded in two materials, assembled, and decorated. It replaced a three-machine cell.

In the cup handle cell, the parts, cored out by gas assist, are robotically removed and transferred to a cooling/shrink fixture that strengthens them for overmolding. They are then automatically transferred to a computer-controlled vision system that manipulates a Scara robot to properly orient the handles for robotic pickup and overmolding.



Space-saving automated parts handlers remove, cool, and strengthen the handles prior to overmolding. A vision system monitoring the presence of the molded handles on a conveyor controls an Adept Technology Scara robot downstream. This robot then orients the handles for automatic transfer into the overmolding machine. (Trying to overmold the handles on the same press would have blown the cored-out handles to pieces.) The cell's 12-cavity mold is equipped with three zones of gas-assist control and is capable of producing about three million parts/year. 

Company officials agree that MCP's success in developing core competencies in such specialty areas as multimolding and gas assist for serving its cosmetics clientele was directly responsible for the company's decision to diversify into other high-volume markets, like telecom and consumer products. Such markets rely on similar specialties from an exclusive number of single-source suppliers. Still, MCP has no intentions of abandoning personal care. 

Ruby says managing growth while diversifying is the company's biggest challenge. "We are building on our growth in cosmetics and are looking at different available markets and technologies to which we can apply our tricks. We've begun looking into PIM, for instance. We have a five-year expansion plan in progress. I believe that a 10 to 15 percent growth rate over the next five years is manageable." 

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