Toolmaker Triangle Tool Corp. of Milwaukee never had built tools as large as it made for the John Deere 8000-series hood assembly, molded by Bemis Manufacturing Co. of Sheyboygan Falls, Wis.
The injection molded and coinjection molded project took two awards in the SPI Structural Plastics Division's new-products competition, for best agricultural component and best single part. The single part honor focused on the structural glass-filled polybutylene terephthalate space frame beneath the hood panels that also routes cooling air and electrical wiring, and serves as a heat shield between the engine and thermoplastic body.
Bemis launched a 6,600-ton coinjection machine to mold the parts, requiring it to expand its building. The company worked with material suppliers and designers to come up with a custom polycarbonate/polybenzimidazole resin for the panels.
``What may not have been attempted 10 years ago was made possible with advances in [computer-aided-design] mold flow, tool manufacture, machine controls, material formulation and processing knowledge,'' Bemis said.
The 56 different parts submitted for consideration in SPD's competition, held during its April 14-16 annual meeting in Dearborn, represented gas-assisted, coinjection and reinforced injection molding; and structural web and structural foam molding. Some used a combination of processes on just one component.
They also ranged in size, from a sole of a shoe to panels considered the largest of their kind in production. Other winners from the design competition:
* Automotive: Horizon Plastics Co. Ltd. used the capabilities of the structural web process to create a spoiler for Ford Motor Co.'s 2002 Explorer. The company, working with mold maker FGL Precision Works Ltd. of Concord, Ontario, needed to mold a large part with varied wall thickness for the ABS spoiler. It also required a strong Class A surface to ensure minimal post-mold finishing.
* Building and Construction: A structural web process came into play as molder Fort Wayne Plastics Inc. of Fort Wayne, Ind., and toolmaker FGL Precision Works worked with original equipment manufacturer Hancor Inc. of Findlay, Ohio, to reduce the wall thickness in a stronger yet lighter polyethylene envirochamber. An integrated rib design creates a stronger system, which requires less backfill material during installation, saving both material and labor. The entire project can minimize landscape damage.
* Electrical: A RIM polyurethane elastomer frame replaces aluminum on the multipane Impact Innovator glass door for use on grocery-store freezers and molded by OEM Hussman Corp. of Bridgeton, Mo., using a mold from EPW Inc. of Elkhart, Ind. RIM cuts energy loss typical in a metal-frame door by an estimated 25 percent, while also providing access to the center of the three glass panes for an electronic system used to eliminate condensation.
* Environmental: Farmers can harvest the soybeans used in the composite material that makes up the access door on their John Deere harvester combine. Bayer Corp. created a soy-based PU RIM system, which Deere uses in its first commercial application in a high density structural foam system. Deere estimates it could use about 225,000 pounds of soybeans in the material. The composite, called HarvestForm, will go onto body panels on the entire line of John Deere Harvest Works combines starting with this model year. Molder GI Plastek Inc. of Newburyport, Mass., also used its proprietary ProTek in-mold coating system to eliminate painting.
* Industrial and Military: A polypropylene processed through low-pressure structural foam is replacing the metal on natural-gas compressors for refueling. The structural foam, molded by Horizon Plastics with a mold made by FGL Precision Works, offers reduced costs, easier installation and a snap-fit cowl for quick assembly for the units that can work either in a group for a quick refueling or as a single home-based system.
* Judge's Award: GI Plastek adapted its ProTek in-mold decorating process to meet increased demands from Caterpillar Inc. for its Challenger tractor's clear coat on all exterior trim pieces, including metal and plastic components. The resulting improvements exceeded the manufacturers' weathering requirements of three years by a full year. At the same time, Challenger extended its use of RIM to fenders, a heating and air-conditioning cover and outer roof.
* Lawn and Garden: John Deere wanted to borrow from the auto industry to offer various models of lawn tractors based on one platform. Molder Bemis Manufacturing Co., mold maker Delta Mold Inc. of Charlotte, N.C., and Brooks Stevens Design of Grafton, Wis., together created 35 molded components that could be mixed and matched to produce more than 20 distinctive models in four series for two separate brand names based on two chassis. The procedure required a variety of materials and processes. For instance, the alloy developed for the hood would not meet impact criteria, so the team opted to use ABS as a core material. In total, the tractors use more than five materials, while Bemis makes them with injection, gas-assist and coinjection molding.
* Materials Handling: Plastics are going on tour with the Spectralite Case, a 20 percent glass-filled PP case designed to hold musical instruments during transportation. Made through low-pressure structural foam by Horizon Plastics with mold maker FGL Precision Works for Spectrum Manufacturing Inc. of Toronto, the Spectralite replaces plywood. An internal ribbing system permits placement of separators to create different compartments to handle a variety of sizes of instruments and components.
* Medical and Scientific: Thieme Corp. of Teningen, Germany, tackled 12 separate RIM components to produce the computer tomograph - or CT - enclosure, including the largest known single-shot RIM part in production for the rear panel, weighing in at 74 pounds. The structural strength of the low-pressure structural foam components, produced with a mold by Grauer, Form Plus & Golarsky of Endigen, Germany, provides enough support and rigidity so the entire unit can be moved in an assembled position. In-mold assembly aids such as holes, ribs, bosses and metal inserts reduced part, tooling and assembly costs.
* Recreation and Leisure: A mix-and-match series of ladder components for above-ground pools allows users to create a system to their own requirements. The structural foam high density PU system molded by Horizon Plastics with molds from FGL Precision Works and MSI Mold Builders Inc. of Cedar Rapids, Iowa, can adapt to a basic ladder for simple access or one with 36-inch steps.
* Retail Consumer Products: A computer control built into the Petsafe electronic feeder created by Radio Systems Corp. of Knoxville, Tenn., allows dog owners to drop a predetermined amount of food into pet dishes for feeding. The control in the structural foam polyethylene can help pet owners control their pets' access to food. The container can hold up to two weeks' worth of food.
* Transportation: A carbon-fiber/nylon composite from DuPont used in the injection molded racing wheels for off-road, four-wheel, all-terrain vehicles are stronger, more responsive and lighter than a typical aluminum unit. The wheels made by Pressure Plastics of Chesterfield, Mich., for Hiper Technology of Wichita, Kan., are the first carbon-fiber racing wheels for ATVs and are rounder and truer, the makers said. The wheels already have been ridden in competition in national races.