Aeroboy

Driving JIT with new technology implementation

Wouldn’t it be great if you could buy all of the high-tech equipment your heart desired? Imagine all the problems that could be solved. Your molding operation would practically run itself, right? Of course, to be successful molders must plan and implement that new technology in an intelligent way, taking human factors and specific applications into account.

That’s the conclusion World Class Plastics Inc. (WCPI) reached when it set out to add optical gauging, automotive degating, and a sophisticated SPC system to its 32,500-sq.-ft. plant in Russells Point, OH. WCPI is a privately held custom molding operation that has grown in seven years from one press and one customer to a $10 million-plus molder producing 10 million close-tolerance parts/month.

This plant specializes in JIT production for customers in the automotive, medical, appliance and industrial markets (see “JIT on Steroids,” July 2000 IMM, p. 14). Many products go directly from floor to truck in this scenario, so the need for automation, tracking, and accuracy is obvious. Yet, before implementing any new technology, WCPI first explored the benefits it wanted to achieve and then looked for the best solution and implementation method to support those goals.

DEGATING OPTIONS

“We strive to minimize variation in the process,” says David Disniewski, engineering and R&D manager. This is why the company decided to install CNC degating systems (Aeroboy SK-250 from >SAS< Automation). WCPI has 25 Sumitomo presses ranging from 18 to 350 tons, each of which is serviced by Yushin servo robots and sprue pickers. The degating systems were placed on the end of the servo robot traverse beam.

“Using CNC degating instead of doing it manually produces more consistent results, and the quality goes up,” explains Wisniewski. In addition, the system helps molding technicians, each of whom are generally responsible for running five to six machines, to manage the process and consistently get good parts.

To help ease the installation of the systems, WCPI purchased a modular system. “The quick-change end-of-arm tooling (EOAT) system slide in and clamp rather than screw down,” explains Wisniewski. “As a custom molder, we are always changing jobs. We have two dedicated presses, but the rest can run jobs from two to three days down to 6 hours. So we needed a flexible system.”

A recent visit to the plant illustrated this concept. In a workcell with a 160-ton press, instrument cluster bezels for the PT Cruiser were automatically degated and trimmed. The tool that WCPI inherited wasn’t designed for ease of manufacture, according to Wisniewski. It should have been hot-edge gated; instead, there were two small subrunners coming off the hot manifold. “we have to nip the subrunners and flush trim the gates. On runner is situated behind a rib so we needed a reach-around cutter. JDV Products built a custom nipper blade from WCPI specifications.

PUMPED-up SPC

Another component of the WCPI strategy involved having each workcell take responsibility for its production and quality goals. To that end, the company purchased a 2-bit SPC software package called Synergy 2000 (Zontec) so named because it consists of three parts that work together.

One part is used by production technicians for real-time data collection and input. Data inputs automatically into the system through calipers micrometers, and height gauges. Another capability helps quality managers and engineers establish control and spec limits to analyze data. A third component lets managers monitor the processes in real time from a single screen and create reports.

Brett Johnson, director of quality, explains how this new technology was introduced. “Rather than forcing this system on our employees, I went to a trainer’s workshop first, and then shard what I learned with representatives from all three shifts. Over a weekend, we completed associated training and went into production on a Monday. The process was seamless.”

In the near future, the system will allow selected customers the ability to review actual data through a secured Internet connection. This eliminated an additional QC check normally performed when the parts are received.

The new system was also flexible enough to incorporate a suggestion from molding technician Greg Postle. He noticed that manually entering part numbers introduced unacceptable levels of human error. He asked if parts could be assigned bar codes for keyless entry. “We produce about 400,000 part and shipping labels per year,” says Johnson, “so the idea was immediately investigated.”

A bar code containing the part number is now printed on each job card. Technicians scan the code with a pen, which then prompts the system to enter the part number. In another version of the job card, scanning the code produces a bar code label for shipping. Both systems have reduced error throughout the plant.

AUTOMATED MEASURING

Right-tolerance, visually critical parts are the order of the day at this facility. WCPI produced, for example, several tiny components found within every GE refrigerator around the world. These parts have tolerances of +30pm.

To ensure that parts meet dimensional requirements, WCPI added a video measuring system (Avant Zip 600 from OGP) for quality checks. Target dimensions are first input into the system along with a part number. The automated probe then does the measuring.

“We needed something that could inspect anything we mold, and after extensive research, we knew that this was the system,” says Johnson. Cost savings on inspection alone are estimated at $100,000 annually. – Michelle Maniscalco.

Reprinted with permission from Injection Molding Magazine;  © 2001 by Canon  Communications Inc.