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IRVINE, CALIF. — The sheer number of gas-assisted injection molded parts entered in the SPI Structural Plastics Division's annual design contest sparked interest, but when the judges were done, diversity ruled the day.

The big winner, in the form of the Conference Award, was a complex, 36-part, heavy-truck instrument panel for Freightliner Corp. that incorporates parts made using four different processes, including gas injection. The component was produced by Consolidated Metco Inc.'s Plastic Division in Cashiers, N.C.

The Single-Part Award went to a Deere & Co. lawnmower chassis compression molded from sheet molding compound.

Of 74 products, 21 featured some application of gas injection — nearly double the previous high of 11 for that process registered in each of the previous three years' contests, according to the organizers of the April 13-16 meeting in Irvine. The Society of the Plastics Industry Inc. is based in Washington.

Solid-wall injection molding was the most popular process, finding use in 23 of the product entries, while 21 entries employed low-pressure structural foam molding, previously the contest's dominant process.

Here is a summary of this year's winners in their respective categories.

MEDICAL: Hewlett Packard Co.'s ImagePoint Enclosure, featuring 10 pressure formed parts made by Arrem Plastics Inc. of Addison, Ill.

CONSUMER PRODUCTS: A coinjection molded, polypropylene drinking mug designed and manufactured by Co-Mack Technology Inc. of Vista, Calif. Incorporating a proprietary core material made by San Diego's Phase Change Laboratories, the mug keeps the liquid inside at a stable hot or cold temperature for a long time.

MATERIALS HANDLING: A pair of polyurethane motor compartment panels for a pallet truck, reaction injection molded by GI Plastek's RIM Business Unit in Marysville, Ohio, incorporating a two-color, in-mold coating process. Produced for Baker Material Handling Corp. of Summerville, S.C., these 61/2-pound panels are made of 18 percent glass-filled RIM PU in cast kirksite tooling developed by Pattern Guild in Auburn Hills, Mich. In addition to the two-color aesthetics, the panels' impact resistance and insulating properties helped them to replace the previous metal panels. Incorporation of an innovative hinge also lowered costs by eliminating metal inserts.

INDUSTRIAL: The Gerber Bristle Square, an injection molded nylon base unit with 2,450 nylon bristles that serve as a base for supporting fabric being cut by a cutting cam mechanism. Alliance Precision Plastics Corp. of Rochester, N.Y., did the tooling and molding for Gerber Garment Technology Inc. in Tolland, Conn. The lightweight, corrosion-resistant bristle block also features 1,021 tiny holes in the base that serve as vacuum holes, allowing the machine to draw the cloth tightly to the cutting surface.

AGRICULTURE, LAWN & GARDEN: A one-piece SMC chassis and suspension system for a rear-engine riding mower, compression molded for Deere & Co. Technical Center by Bailey Corp.'s PreMix unit in Lancaster, Ohio. The piece also got the best Single-Part Award.

RECREATION: A PP flexible pool panel with living hinge, made using the low-pressure structural foam process by Cobourg, Ontario-based Horizon Plastics Co. Ltd. for Kafko Manufacturing. The living hinge allows pool fabricators to make in-ground pools of virtually any shape using identical, patented Multi-Flex panels, which come in heights of 42 and 48 inches. A number of strips drilled in different lengths set the curvature of the panel, which are made using aluminum tooling from Canada's K&K Tool Ltd. The panels also nest together, facilitating shipping.

BUILDING & CONSTRUCTION: Series of sledgehammers featuring colorful plastic handles injection molded by Avtech Plastics of Fraser, Mich., using a glass-filled olefinic/styrenic Hivalloy resin alloy from Montell Polyolefins. These striking hammers from Lifetime Tool Co. of Madison Heights, Mich., come with drop forge steel heads weighing 8, 10 or 12 pounds. The handles dampen vibrations, eliminate splinters and are guaranteed against breaking, cracking or separating from the integrally molded steel head for at least five years.

TRANSPORTATION: Intake duct made by Japan's Bando Chemical Industries Ltd. for Fuji Heavy Industry Ltd., using a novel gas-assisted injection molding technique to produce a smooth, large-diameter inner core-out surface. Bando makes these solid-wall ducts out of 40 percent glass-filled nylon.

BUSINESS EQUIPMENT: Three-part printer chassis injection molded by All Service Plastic Molding Inc. of Dayton, Ohio, for Lexmark International Inc. Made of highly filled polyphenylene oxide/polyphenylene ether material using tooling from Minco Tool & Mold Inc. of Dayton, these parts are positioned precisely by means of mating features molded into each part. The three parts contain more than 65 machine interfaces and combine to provide structural rigidity for the entire machine.

PEOPLE'S CHOICE: Selected by popular vote of many of the meeting's 323 attendees, this award ended in a tie between the previously noted Freightliner Corp. truck instrument panel and a multilevel telecommunications power array molded by Reiss Corp. of Englishtown, N.J. The latter, made with tooling from Model Die & Mold of Grand Rapids, Mich., includes a 20-pound counterpressure structural foam enclosure of 10 percent glass-filled polycarbonate. Each of the unit's seven levels supports 150 pounds of subsystem components. The modular array allows for numerous configurations, employs regular and gas-assisted injection molding, and allows for insertion and removal of hot-swappable modules.

ENVIRONMENTAL AWARD: Horizon Plastics Co. Ltd. garnered a second award with its compost bin, which blended 5 percent crumb from scrap car tires with reprocessed high density and linear low density polyethylene. Horizon, using multicavity aluminum tooling from Concord, Ontario-based FGL Precision Works Ltd., molds the part in one cycle in a 300-ton, multinozzle, low-pressure structural foam machine.