COLOGNE, GERMANY (Dec. 8, 1:25 p.m. ET) — The polymer used in wood plastics composites (WPC) is usually polypropylene or PVC. But Evonik Industries AG has worked with machinery supplier Reifenhäuser GmbH & Co. KG to develop an acrylic-based Plexiglas Wood brand.
The new material is compounded and extruded into 50-75 percent reinforced WPC profiles on a Reifenhäuser direct extrusion line.
Carlo Schütz, manager innovative projects at Evonik, says the idea of acrylic-based WPC arose from using acrylic products as protective coatings on conventional wood product surfaces. This led to the question: Why shouldn't natural fibers be combined directly with acrylic binders in one material, namely with one of the most weather-resistant polymers of our times?
Evonik went on to develop colorless and colored modified acrylic containing binder and adhesion additives. These ensure optimal coupling between the acrylic and cellulose components of the reinforcing wood fibers. Additional expensive stabilizers are not required, as shown in 10,000 hours of artificial weathering on acrylic- and PP-based WPC profiles, says the company.
Schütz has presented a table showing that natural and colored Plexiglas Wood has a flexural modulus of 8,800MPa and 10,000MPa. Although below some tropical woods, these values are close to or slightly higher than beech, spruce and red cedar.
Flexural modulus was found to be much higher than for PVC-WPC (6,500MPa) and two different PP-WPC formulations (3,200 and 4,500MPa).
Plexiglass will present the material at the Nova Institut's 4th WPC Congress in Cologne, Germany, scheduled for Dec. 13-14, where it is one of six finalists in the innovation awards. The material will then be launched on the market in 2012.