Automotive supplier Prince and tooling material supplier Ciba Specialty Chemicals Corp. have developed a composite board that can shorten time-to-market cycles for injection molded engineered thermoplastic prototypes.
A user can develop a mold-tool core and cavity on any standard computer numerically controlled milling machine with minimal setup time and without buying specialized equipment.
As conceived, the new bridge tooling can run as many as 250 parts in a design-intended material. That gives customers an earlier opportunity to evaluate prototypes and validate design concepts.
Ken Filipiak, Prince's lead tool engineer, introduced the composite board in a May 20 technical paper at the Society of Manufacturing Engineers' Rapid Prototyping and Manufacturing meeting in Dearborn, Mich. A Ciba Specialty Chemicals unit exhibited the material under the trade name Cibatool-Express.
Ciba owns the technology and will manufacture the aluminum-reinforced polymeric board at its 110,000-square-foot facility in East Lansing, Mich.; Prince will draw royalties on the basis of sales. Both companies are listed on pending worldwide patent applications.
Formulated with thermosetting resin and aluminum filler, the material cannot survive volume production runs and is not capable of generating a 90-degree inside corner, typically requiring electrical discharge machining. Neither disadvantage may matter to the prototype world.
The total project began in April 1997, when Prince was ``looking for a high-speed-machinable material that would allow us to fully cut cores and cavities,'' Filipiak said in a telephone interview. He also is toolroom manager in Holland, Mich., for Prince, a subsidiary in Johnson Controls Inc.'s automotive unit.
Prince asked three major board manufacturers about cultivating the idea and, in July, selected Ciba, Filipiak said.
The new entry becomes the 16th in Ciba's family of Ren Shape, Polyboard and Cibatool board materials, said Bill Geresy, marketing manager in East Lansing with the North American tooling business unit of Ciba's performance polymers division.
The team isolated its first compound in October and achieved a material with dimensional stability in late December.
The team met its goal of producing 250 prototype parts, using polypropylene, ABS and polycarbonate for a range of processing characteristics, ``from low-temperature and sticky to brutally hot and very coarse,'' Filipiak said.
Ciba is establishing beta test sites to use the composite boards for automotive, medical, business machine and electrical/electronic tooling to make prototype parts such as housings and bezels.
Geresy envisions the board costing about the same as a comparable piece of cast aluminum. A decision remains to be made about whether to price by the linear foot, as in the model-making niche, or by stock sizes and weights, as in the industrial market.
In his paper, Filipiak described Prince's machining of composite boards to mold prototypes initially of an automotive visor bracket cap, a visor track extender and a visor backbone.
``By combining high-speed CNC milling with the new composite board, we have been able to produce core and cavity injection mold inserts in 15-20 percent of the time required to manufacture the molds from traditional methods and materials,'' Filipiak wrote.