Taking Up Tooling Boards

Tooling boards, modeling boards, machinable slabs — all are common terms for tried-and-true materials used to produce master models and prototype tooling. Developed decades ago to replace traditional wire and plaster master model techniques, tooling board is made from filled polymer materials. Tooling boards can be bonded together to form larger blanks and large blocks from which models or tools can be CNC-machined.

Currently, demand is high for tooling boards. A number of companies (listed in alphabetical order, below) produce a wide variety of tooling board stock in varying densities that are suitable for creating models, low-run prototype tools or production fixtures. While coefficient of thermal expansion (CTE) can be quite high, up to 30 to 40 in/in/°F x 10-6, ease of machinability and relatively high strength makes the material suitable for many applications. Glass microspheres are commonly used as a filler to reduce weight and help control dimensional stability.

Airtech International Inc.(Huntington Beach, Calif.) sells Modelmaster B182 epoxy tooling boards, designed for use with tooling prepregs that cure at 250°F/121°C. The product is formulated to be compatible with the company's tooling prepregs for customers making composite tooling. airtech.gocomp.biz/34

Axson (Cergy, France and Eaton Rapids, Mich.) supplies machinable epoxy tooling slabs along with epoxy laminating and casting resins. LAB 973 is a high-temperature, low-CTE tooling system, complete with boards, the company's Mastercoat tooling surface coating and a bonding adhesive for creating large work pieces. A noted sports car racing team has used Axson's product to make low-run production tooling for carbon/epoxy parts cured in the autoclave at 125°C/257°F and a pressure of 4 bars/58 psi, says Axson's North American representative Tom Budd. axson-na.gocomp.biz/5

Coastal Enterprises Co. (Orange, Calif.) manufactures a range of polyurethane tooling board products: the basic Precision Board (PB); PBHT (or High Temperature) for 300°F/150°C applications; and PBLT (or low temperature) for applications around 200°F/93°C. Polyurethane chemistry is typically less expensive than epoxy, says president Chuck Miller, and the product is available in densities from 4 lb/ft3 to 40 lb/ft3 in thicknesses up to 20 inches/500 mm. The company can custom-bond blocks to customer specs for making special shapes or large tooling plugs, with fast turnaround time. precisionboard.gocomp.biz/41

Elliott Co. of Indianapolis Inc. (Indianapolis, Ind.) manufactures large sheets and blocks of its trademarked ELFOAM polyisocyanurate foam, up to 24 inches/600 mm thick, in a continuous process. ELFOAM is available in densities from 2 lb/ft3 to 6 lb/ft3 for carving or shaping models or basic plugs intended for low-temperature, nonautoclave applications. elliottfoam.gocomp.biz/4

General Plastics Mfg. Co. (Tacoma, Wash.) manufactures rigid, high-density polyurethane foams for a wide variety of applications, including tooling, prototyping and vacuum-forming fixtures. The company's FR-4500 polyurethane tooling board has a glass transition temperature of 225°F/107°C and is reportedly suitable as a layup model for low-temperature-cure prepregs, says Ted Hile, the company's market development manager. The proprietary additives include an antistatic material that ensures shavings fall away during machining rather than sticking to the cutter. generalplastics.gocomp.biz/31

Goldenwest Manufacturing Inc. (Cedar Ridge, Calif.) has been producing polyurethane tooling board products since 1970, including Butter-Board, a glass microsphere-filled syntactic urethane developed for easy machining and paintability. Cliff Stewart, the company's business manager, says that its R1/HG3000 urethane product is well suited to aerospace master models and tooling, thanks to good dimensional stability and the fact that large blocks can be custom cast to customer size specs. goldenwestmfg.gocomp.biz/1

Huntsman Advanced Materials (The Woodlands, Texas), developed Space Block tooling boards years ago in conjunction with NASA, during design of the Space Shuttle. Today, the company offers in the U.S. a wide range of RenShape polyurethane boards as well as metal-filled fixture boards, and an epoxy tooling board — intermediate-temperature RenShape 5008 — (additional epoxy board products are available in Europe). The company says it employs special processing while casting its epoxy boards to prevent warping during machining and shaping. Italian automotive fabricator ATR Group (Colonnella, Italy) recently used RenShape 5055 epoxy board to produce all of its models for a new Italian micro-car, the k200. Tools built on the models were autoclave-cured from 60°C to 90°C (140°F to 194°F). Composite material supplier Advanced Composites Group Ltd. (ACG, Heanor, Derbyshire, U.K.) is a major distributor of Huntsman model materials and has collaborated with Huntsman on a new epoxy board, termed TB750, a derivative of the 5055 material. huntsmanadv.gocomp.biz/12

Founded in 1952, Tool Chemical Co. Inc. (Madison Heights, Mich.), a division of CASS Polymers Inc., manufactures a suite of epoxy tooling planks, including The Red Stuff, designed to form foundry patterns and dies, says the company. toolchemical.gocomp.biz/1