Göran Grubbström
Göran Grubbström

Göran Grubbström

Thesis

Reactive extrusion of wood-thermoplastic composites.

Supervisor

Professor Kristiina Oksman

Research

Wood-thermoplastic composites (WPC) are a type of wood composites made of wood flour/fibers and thermoplastics. Using wood to reinforce the plastic leads to a higher stiffness compared to the neat plastic and it may also strengthen the plastic. The WPC have good resistance to moisture since the hydrophobic plastic encapsulates the wood reinforcement and WPCs can by this relatively high thermoplastic content be manufactured using traditional methods for thermoplastics, like extrusion and injection moulding.  

My research is about improving properties of WPCs by reactive extrusion. Crosslinking the composite can be done by reactive extrusion and this result in better strength and stiffness of the material. The long-term properties of the material are also improved by crosslinking. The creep response is lowered.  

The reactive extrusion process has a narrow processing window and several aspects of crosslinking the WPC are investigated to optimize the process in terms of crosslinking density and processability, for different types of thermoplastics and wood flours.  

This project is funded by Skellefteå Kraft and Nordea-stiftelsen.