Wood is a sustainable, renewable and versatile material. When processed, dried and protected correctly it becomes a high quality, stable material. However, the increasing use of environment-friendly coatings can cause problems with rot in wood panels, due to water retention in the coating/wood interface. Moisture ingress into glue can lead to mechanical failure. This project uses recent advances in magnetic resonance imaging techniques (MRI), which allows visualisation of the moisture content in wood at its interface with air, coatings and glue. Moisture profiles in untreated, glued and coated wood, drying and rehydrating, will be measured. A surface-layer drying model will improve electrical impedance moisture sensors used in kiln drying control. Quantitative measurements of coatings and glues as a function of composition will assist in the development of improved products. Economic and environmental benefits are gained through an understanding of wood properties.
The objectives of this project are:
1) to use MRI to measure moisture profiles in wood and wood/coating/adhesive layers
2) to use MRI to parameterise the wood drying profile at the surface layer for a range of samples and conditions
3) to build a model of surface layer drying, and to implement this model in kiln drying control software to achieve a higher performance
4) to use this drying model to improve the methodology of alternate, lower cost electrical impedance moisture measurements
5) to create a formulation template for water-borne coatings and information on durability from measurements on a range of samples with different coating formulations
6) to determine the effect of moisture at the wood/glue interface by measuring mechanical performance related to moisture levels
7) to provide this information to suppliers, manufacturers and end users
8) to assess the possibilities for the use of MRI in the timber process and products industry.
During the first milestone, the wood drying and coatings probes were built and tested, wood moisture calibrations made and preliminary measurements completed for drying, coatings and glues work.
The second milestone centred on drying, coatings, glue and looking at MRI characterisation of wood drying, coatings and glues and the early stages of development of drying models. Work on coatings has moved forward in several ways with projects developing beyond the scope of the original MARWINGA proposal. Considerable interest has been aroused in the project's unique ability to MR profile through coating layers and several commercially funded projects have commenced as a result and papers published. Work on glues was divided into studies of curing and water penetration through glue layers.
The third milestone concerned the achievement of the drying model development, the model testing and the development of the sensor. As a benchmark to gauge success, a commercial product has been developed and will be marketed by Traetek and WSAB once licensing negotiations are complete early in 2003.
The project was disseminated and following meetings, new industrial contacts have been pursued and future sponsored programmes are under active consideration.
FORESTRY, NON-FOOD PRODUCTS, QUANTITATIVE APPROACHES AND MODELLING
Scientist responsible for the project
Mr PETER McDONALD
GU2 7XH Guildford
United Kingdom (The) - GB
Phone: +44 1483 876798
Fax: +44 1483 876781
||The University of Surrey
||01 February 2000
||745 754 €
|Total EC contribution
||514 012 €
|Web address of the project