Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

Sustainable and renewable reactive oil based resin systems for timber preservation. - NF0604

Description
This project will demonstrate the use of a bioderived reactive vegetable oil as an alternative chemical for timber preservation. Wood preservation chemicals are an important market sector with over 1,9676,000 m3 of softwood treated per annum in the UK. It now faces a significant challenge as the existing CCA and creosote systems are phased out. Preservation treatments relied on the utilisation of heavy metals and the growing concerns relating to possible toxic effects have led to a world-wide ban. This market is demanding in terms of environment and health issues. As an end application it will demonstrate to consumers the benefits of using a bio-derived technology and this will help develop other markets for non-food crop technologies in the UK.

Softwood timber production is set to increase up until 2020 whilst the coniferous standing sales index (price per cubic metre) has continually fallen since 1995. Therefore a means for improving the quality and increasing the range of end uses available for softwood timber is urgently needed. Meanwhile new materials are required in the offsite construction sector and new construction techniques are promoting the increased use of wood through timber framed housing. In meeting the demands of these new markets there are two principle challenges for UK grown softwood; dimensional stability and resistance to decay. The heat treatment of wood with a bio-derived vegetable oil resin system can be used to improve the dimensional stability and preserve the timber.

The use of an oil-heat treatment offers a solution to both of these problems. Oil heat-treated wood shows greater resistance to fungal decay, and has better dimensional stability than untreated wood. Oil impregnation allows the fast application of the heat to the wood, and excludes air during the treatment phase thus reducing the scope for strength loss seen in other heat treatment systems. Past traditional timber preservation techniques have included the treatment of wood through simple oil impregnation at ambient temperatures. However these methods although effective, involve repeated top up treatments. In more recent hot oil treatments there is a tendency for the oils to bleed from the wood. New developments in bio-derived oil based resin technologies has provided an opportunity to introduce a curing step in the timber treatment process that will combine the benefits of heat treatment with the formation of a durable chemically bonded surface layer. This would reduce the problem of oil bleed from the timber and provide a protective surface coating.

The key objectives of this proposal are therefore to:
· Provide a detailed technical assessment of the processing and properties
· Demonstrate this approach on industrial products in the wood decking and playground furniture sector
· Assess and map the opportunities and barriers to exploitation of this technology in this sector

In achieving these objectives the results of the project will be widely disseminated in partnership with the 2 industrial collaborators, BSW and Clifford Jones Timber. BSW is the largest sawmilling business in Great Britain. BSW sawmills are located throughout the UK, with sites in Scotland, England and Wales. BSW supply a range of domestic and industrial timber products for the construction, packaging, fencing and decking markets. Clifford Jones Timber, based in Wales, is one of the leading manufacturers of Machine Round Timber in the UK. They supply the market leaders in adventure playgrounds, construction, utilities and retail sectors. Both companies pressure treat their products with preservatives to enhance service life. In this project a series of products will be pressure treated using the existing method with the bio-treatment oil and placed on display at retailers, trade fairs and shows. Two product applications will be considered, the wood deck and playground equipment sectors. These markets are high profile and will provide good examples that are easily understood by the consumer.
Objective
1 Impregnation Protocol
1.1 Develop impregnation method on small test samples for 3 species of woods with bioderived system.
1.2 Optimise bio-derived oil for impregnation with Cambridge BioPolymers.
1.3 Develop heat treatment process to cure systems with and without the presence of a nucleophile

2 Test and Evaluate Specimens
2.1 Measure strength properties of heat treated oil impregnated wood samples
2.2 Test samples of impregnated wood for biological decay resistance
2.3 Test samples of impregnated wood for weathering, leaching and dimensional stability
2.4 File new IPR for this application

3 Dissemination
3.1 Scale up process on component products selected for decking and playground furniture applications with support from Cambridge BioPolymers and BSW
3.2 Provide technical data sheets on treatment process and properties of treated products
3.3 Display products at 2 dissemination events organised with sawmilling collaborators.
Project Documents
• Final Report : Sustainable and renewable reactive oil based resin systems for timber preservation.   (447k)
Time-Scale and Cost
From: 2005

To: 2006

Cost: £70,890
Contractor / Funded Organisations
Clifford Jones Timber Ltd, University of Wales, Bangor, Cambridge Biopolymers Ltd, BSW Timber Ltd
Keywords
Agri-Industrial              
Agro-Forestry              
Arable Farming              
Crops              
Farming              
Forestry              
Oilseed Rape              
Fields of Study
Non-Food Crops