The technology, licensed from Michigan Technological University, enables the production of curved molded furniture parts with higher design flexibility, reduced assembly costs, and greater strength than many conventional parts.  The plant is the first to move oriented strandboard technology beyond OSB flat panels and into industrial products requiring compound curves and a high strength-to-weight ratio.

Similar to manufacturing OSB, the product starts as narrow strands of aspen wood.  A heated metal die compresses a loose mat of aspen strands at high pressure for three to five minutes to form the molded product.  The dies are milled from cast iron or aluminum at a fraction of the cost of tooling for injection molded plastic.  The process is carried out in an enclosed environment to ensure safeworking conditions. 

Strandwood Molding is initially focusing on producing chair backs, seats, armrests, and shells (one-piece units forming an integral seat and back). Strandwood's customers cover these hidden parts with foam and fabric in upholstered seating.  With a density of 42 lbs/cu ft (673 kg/cu m), the material has weight, machining, stapling and mechanical properties equivalent to medium density hardwood.  The molded contours serve in ergonomic designs to more closely fit the body.  End customers appreciate that MDI adhesives eliminate the problem of formaldehyde release into the office environment, which can be an issue with composite wood products based on urea formaldehyde systems.

The company has worked with Huntsman Polyurethanes to develop formulations that optimize MSB processing.  Strandwood also allies with furniture designers and engineers to create seating applications with channels, deep recessions, and molded flanges not possible with other wood products.  One customer design won a Gold Best of Show Award at a recent office furniture tradeshow.  Another achieved cost savings of $15 per chair back – and obtained a more attractive look – by substituting molded strandboard for several pieces of plywood previously combined with metal brackets.

"By milling special features into the dies, we can mold enhancements into the finished part that would otherwise have to be accomplished by machining," says Bruce Haataja, president of Strandwood Molding and one of the technology's inventors. 

"We can mold bosses for better mating with attachment bases.  We can incorporate rolled edges, channels and ridges to stiffen parts," says Bruce.  "We can even mold holes and centerlines."  He notes that Strandwood has eliminated any shaping operations by pinch trimming some products in the molding dies.

Bruce says that his company is as likely to compete with injection molding plastic designs as conventional wood products.  "We can offer a wood component with much of the same design flexibility and stability as plastic, but at much lower product volumes."  He adds that MSB technology in the office furniture industry is only a start.  The product can be used in many other applications that require a high strength-to-weight ratio and curvaceous surfaces.

Bruce Haataja, Strandwood Molding, Inc. USA
Phone +1 906 487 9768
Fax +1 906 487 9770
www.strandwood.com

MAR 2001