When Bradford Stewart & Company wanted to put Kipp Stewart’s designs on a fast track to production prototypes, they looked to Jim Lemke of Innovative Surfacing in Fremont, California, to create the chair seat/back components of CORIAN^®.

Challenge: Designs to prototypes in 30 days. On a limited budget.

"They brought us a wish list of 15 pieces," Lemke says."They’d done their homework. We had refined, full-size plans, elevations and perspectives to work with."

Then a four-step, fast-track process began.

1. Value Engineering
Fifteen designs were evaluated on the basis of yield of material, waste and engineering factors and narrowed down to the current line.

2. Mold for Thermoforming
Molds were built from Baltic birch plywood, medium density fiberboard (MDF) and Medite™, similar to MDF but made with more environmentally friendly adhesives. "The cost of creating molds for thermoforming CORIAN^® is 25 percent or less of the cost of creating molds for die-casting aluminum or injection-molding polymers," Lemke says. "And it takes about one-sixth the time."

3. Test Prototypes/Design Refinement
Initial prototypes were tested and design refinements were made, such as repositioning the mounting points of the seat/back for greater strength.

4. Cutting/Molding Finished Production Prototypes
Intricate cutouts were made on a three-axis CNC router on flat sheets of CORIAN^® before thermoforming."Kipp Stewart could have created these shapes in plywood, by first molding wood in stack laminations, then cutting the patterns on a five-axis CNC router," Lemke explains. "Yet plywood couldn’t begin to deliver the performance of CORIAN^® in outdoor applications."

When the CORIAN^® prototypes came out of the mold, no further finishing was required. "CORIAN^® is a through-body material," Lemke says. "What you see is what you get."