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September 1, 2001

11 Min Read
IMM's plant tour: Radical renovation: A change for the better

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Although Cherry discarded 23 machines, the current lineup of 53 presses is more productive and efficient.

It's human nature to resist change, right? Then why did Cherry Automotive's captive molding operations recently undergo some of the most sweeping changes any plant can experience? "The Cherry Corp. once again became private in 1999, and in that process, made a quantum leap in its thinking about manufacturing," says Alex Semiletow, molding manager. "Until that time, molding operations had not been a primary focus. But Peter Cherry, ceo, realized that, to be competitive, we had to vertically integrate our molding facilities and offer best-in-class products." 

Cherry Corp. is a global supplier to automotive, computer, and consumer OEMs, with products that range from electrical switches, sensors, and computer keyboards to automotive switches and modules. Its automotive division provides worldwide OEMs and their suppliers with switch assemblies used in power windows, seats and mirrors, door locks, and steering wheels. It also builds electronic control modules that help operate power seats, sunroofs, convertible tops, and components for safety systems. 

At the heart of these products are molded parts produced at the Waukegan, IL plant that IMM recently visited. It is this plant that management decided to renovate substantially. "It is the only way to effectively meet customer demands for quality, cost, and delivery," says Semiletow. "Cherry is investing in the right people, equipment, and business practices." 

Before and After 
At one time, the 35,000-sq-ft Cherry Automotive molding plant had 76 machines. Today, the number of machines stands at 53 and staffing has been reduced by 55 percent. Yet, even with these reductions, actual production has increased. Behind this apparent inconsistency is a tale of plantwide improvements that began with the hiring of molding manager Semiletow, who assembled a team that could take on the massive change. 

First, the team began facility renovation, opening up the shop floor and significantly improving working conditions. In addition to the main molding floor, there are additional areas—a toolroom and a Class 100,000 cleanroom that produces microswitches. 

While one of the steps in upgrading the plant involved reducing employees, most of this reduction came from temporary staff. Turnover as high as 50 percent in the past meant that the plant often used temps to fill the gaps. Today, however, turnover for the molding team is less than 1 percent. Scientific molding expert John Bozzelli of IM Solutions regularly provides training, and all floor personnel are required to complete the Paulson Interactive Training program. 

Another employee-related improvement involved combining the job of operator with that of mold setter, adding a higher level of skill to the new position. This setter/operator is responsible for production on four or five presses. The result? An 80 percent reduction in reject rates. 

Renovation itself was hectic, according to Semiletow. "We broke down walls and continued production during the entire project. We got so good at it that we only needed 2 hours to disconnect a press and set it up again elsewhere." 

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Part of the team responsible for instituting changes includes (left to right): Dave Lamberti, general supervisor; John Clasen, senior project engineer; Craig Linhart, lead toolmaker; Kim Erdmann, human resources; Alex Semiletow, molding manager; Greg Krueger, project engineer; Plamen Dimitrov, programmer; and Mike Crawford, senior manufacturing engineer.

In a Class 100,000 cleanroom, strips of switch contacts are lined up waiting to be insert molded into microswitches. They reside on cam-operated insert tables, and are heated to grow to the proper dimension prior to molding.


Machinery Makes a Difference 
Before discarding 23 machines, Cherry conducted an in-house evaluation of five different 110-ton machines for six months. Key factors in the test included accuracy, speed, power consumption, and ease of use. In these categories, the Krauss-Maffei (the only press that wasn't an all-electric) beat the competition by a "margin," says Semiletow. 

So Cherry set about establishing a long-term relationship with K-M. "The current five K-M presses are just the beginning," he says. "As we replace machines, the plant will come to contain a majority of these presses." The schedule for new machine purchases is four to eight per year. 

As important as they are, molding machines aren't the only piece of equipment an efficient plant needs. The team installed several others, including overhead cranes and a central mold storage system that consolidated 13 locations into one. The latter system includes a seat of SDRC I-deas for the mold print document control process. Adding sprue pickers (Yushin and Wittmann) to many of the presses furthered the team's goals of efficiency. 

Another major addition was a new production control and process monitoring system, called Shotscope, that works in conjunction with inmold pressure transducers. This real-time system helps keeps track of part quantity and production, and supports HTML documents for a planned company intranet. 

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Establishing a relationship with Krauss-Maffei came after a six-month evaluation of molding machines from five suppliers.

A Seiko robot automatically loads inserts for a high-volume switch. Because Cherry does so much insert molding, it will implement more such robots in the near future.

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The only vertical insert molding machine in the main plant contains a vertical turntable for an eight-cavity mold that is manually loaded. This press is scheduled for replacement.

In the cleanroom, a 100-ton Arburg takes the contact strips and insert molds the microswitch around it.


No Visible Pellets 
A critical improvement to the plant, its materials handling system, has vaulted the facility onto the short list of the world's largest and most sophisticated materials handling systems. Why the team concentrated its efforts in this area becomes clear when you learn that the plant processes 135 different resins on a regular basis. 

"We used to have more than 50 floor hoppers, and we might have stocked 5000 lb of a resin for a job that only uses 1000 lb per year now," Semiletow says. "Clearly, this was an area that needed upgrading." 

A Nucon Wittmann installation that includes 12 miles of pipe and 76 storage bins now handles and stores all of Cherry Automotive's many resins. It begins with A, B, and C storage bins (for high-, medium-, and low-volume materials). Some resins are sent from these bins to a central dryer that supplies 31 drying hoppers, which in turn send pellets to all 53 presses via overhead vacuum hoses. High-volume material is sent to one of seven dedicated dryers, which process 60 to 70 percent of resin volume. At the press, a Nucon blender mixes virgin resin and automatically reclaims regrind material. 

Driving the system are bar code labels that, once scanned, activate the Nucon system to send a particular type, color, and quantity of pellets. Each molding machine contains a label preprogrammed with this information. Putting pellets into the storage bins requires a bar code label as well. Materials pulled off the storage shelf are scanned, and the system then tells operators how and where to add them. Going from a manual to an automatic system has improved efficiency, so much so that Cherry estimates it will pay for itself in 2 1/2 years. 

Lest one think that this system resulted from off-the-shelf components, think again. "It was a problem-solving effort," says Greg Krueger, project engineer for Cherry. "Planning through implementation took five months overall, and required a customized approach from our supplier." 

The build/install of the new and improved material handling system began on Jan. 9 of this year, and the system was operational by April 17. "We've reduced manpower and increased floor space," says Krueger, "and although there are still some growing pains easing into automation from people power, we're convinced this was the right move." 

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After switches and modules are molded, they are sent to this "Work in Progress" area for assembly.

Work instructions that show how to identify defective parts will be integrated into the Shotscope system in the near future.

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Universal storage bins, part of the materials handling system, are meant to supplement dedicated high-, medium-, and low-volume bins.

One of the largest and most sophisticated materials handling systems in the world, Cherry Automotive's new installation contains 12 miles of pipe and feeds all 53 presses.


It's the Process . . . 
Every day, by e-mail, an Excel spreadsheet goes out to Cherry Automotive employees. It contains data collected automatically from the floor, including cycle, cavity, and mold efficiencies; defective parts rates; utilization rates; overall equipment efficiency; changeover time; and schedule attainment. This molding department efficiency report helps everyone focus on the difference between target levels and actual performance. 

Plamen Dimitrov, an in-house programmer, created the computer program that generates the daily report. He also wrote a program to track production. A unique bar code label, when scanned, tells the operator how many parts need to be produced based on the weight of parts already produced. 

Setting target production levels required that the team evaluate what systems were in place, and then decide what to upgrade. "Procedures were outdated, and work instructions were vague," says Semiletow. "There had been high turnover, so training was not consistent." 

The team created a process map from the time orders were received to the day they shipped out. From this data, they wrote a QS 9000-compliant process workflow document, and then made this into common operating procedure. "It was a lot to ask of employees," he says, "so we focused on making changes only where it made sense, not simply for the sake of change." 

Job descriptions are also now documented, with clearly defined requirements for setter/operators, lead operators, quality inspectors, and material handlers. An 11-year company veteran, Vada Adams, is a lead operator who embraces this change. Says Adams, "We're working smarter now instead of harder. Everyone is doing the same thing, so there is no finger pointing. Now, each of us has a clear picture of what we need to do." 

An example of a work procedure that changed significantly as a result of this process is the elimination of part sorting. Previously, operators were forced to sort a variety of different parts at their workstations. Today, only one type of part is delivered to each operator's workstation. Red totes contain rejected parts, blue totes are for good parts, and yellow totes contain hourly shots for quality sampling. 

. . . and the Tools 
Process development went through a similar metamorphosis. To help improve plant efficiency, the team took a look at its toolroom and its tools. "We took 115 of 600 active tools and optimized each one by performing a 2-hour evaluation. Average cycle time reductions were 30 percent, and that figure is conservative," says Semiletow. 

Effective changes included the conversion of 40 tools from tab gates to subgates to eliminate secondary operations. These jobs also received robotic sprue pickers to further automate production. Future plans include similar optimization to additional tools. 

New facilities were also deemed necessary, including sonic cleaners and a low-pressure carbon grinding room to prevent carbon from migrating throughout the plant. For cavity repair, Cherry purchased a centerless grinder and NC orbiter. The company also went to a triage system for scheduling repairs—urgent work now comes first. There is a procedure for work orders, and a form to track work coming in and out. 

The team identified goals—improve cavity efficiency, utilization, and press downtime due to mold repair. Priorities were assessed by the size of improvement possible. The new system was also designed to promote a team environment, in which toolmakers and technicians solved problems cooperatively. 

VITAL STATS 

Cherry Automotive, Waukegan, IL 

Square footage: 35,000 (molding) 

Annual sales: $100 million (automotive division) 

Markets served: Automotive 

Parts produced: 2.5 million/week 

Raw material used: 2.4 million lb/year 

No. of employees: 127 

Shifts worked: Three shifts, five days/week 

Molding machines: 53 presses, 28 to 290 tons—mostly Nissei, Demag, and Krauss-Maffei; one 100-ton Arburg in a Class 100,000 cleanroom 

Secondary operations: Laser etch, pad printing, painting 

Internal moldmaking: Tool repair and maintenance only 

Capital expenditures: $3.2 million for plant renovation in past 18 months 

Quality: QS 9000, ISO 9000 



Contact information
Cherry Automotive
Waukegan, IL
Alex Semiletow
(847) 662-9200
www.cherrycorp.com
[email protected]

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