Material and process development for the production of wood-biopolymer sandwich panels based on renewable resources

Background and Objective

For the production of sandwich panels a continuous process has been developed. The plastic granulate, loaded with a propellant, is scattered between two layers of agglutinated wood particles. By heat and pressure the cover layers are compacted and the adhesive cures. Subsequently, the polymer phase softens, followed by the activation of the blowing agent. To allow the expansion of the polymer, the hot press opens to a predefined distance. By expansion the lightweight foam core bonds to the facings and forms a three layered sandwich panel.

The project aims at the development of an innovative bio-based composite material based on wood and foamed bio-plastic derived from cellulose. The goal is to create a sandwich panel with a light, foamed core structure and high density wood-based facings.

Approach

Based on a cellulose derivative a new expandable granulate will be developed in the project. This opens the possibility to substitute the so far used fossil based polystyrene. A parallel, critical observation by means of life cycle analysis (LCA) evaluates the product and eventually adjusts the project.

Through the project new approaches for the use of wood, as well as new possible uses for by-products of the timber industry can be developed. By substitution with bio-plastics instead of well-known polystyrene for the production of a foam core, an environmental friendly, resource efficient and lightweight material will be estab-lished.