BioMatNet Item: FAIR-CT97-3606

FAIR-CT97-3606
Stresses in beech

To find similar Items, click on a keyword below:
FAIR Area 1.3 - Forestry-Wood Chain : Solid Wood Products : Wood (Lignocellulose)

	Type of Project	Shared Cost
	Contract No	FAIR-CT97-3606
	Total Cost	858,641 ECU
	EC Contribution	765,875 ECU
	Start Date	01/07/1998
	Duration	36 months

Stresses in beech

Objectives

Stress develops during formation of wood as a result of internal biological, physical and mechanical phenomena that take place during longitudinal and radial growth. Internal stress can also be induced as a response to external influences such as gravity, wind, change of competition of neighbouring trees, etc.

Stress is partly released during felling and cross-cutting of a tree, often resulting in end-splitting of logs. Residual stress has serious negative effects on further processing and on the quality of the final products. European beech (Facus silvatica L.), the most important broad leave tree of Central Europe, is known to be extremely sensitive factors that cause internal and residual stresses. This is of increasing technical and economical importance, because there is a trend in the beech timber market towards use in high quality, sophisticated products with high added value, e.g. furniture, joinery, plywood and veneer.

The growing reluctance of European customers to use tropical timber contributes to this trend, because beech is a suitable alternative for many of these woods. National silvicultural programmes throughout Central Europe favour broad leaves and especially beech due to its favourable ecological profile, but there is a deficit of specific beech-related wood quality research.

Significant scientific work has been done in the field of wood anatomy and physiology to understand the phenomena that lead to the development of internal stress. However, there is a lack of comprehensive information about the relation between silvicultural treatment and the tendency of beech trees to develop stress, and practicable strategies to assess and detect stresses in the early stages are also lacking. Furthermore, a clear picture of the technical and economical consequences of residual stresses in the different sectors utilising high value beech timber is not available. Nor is there reliable experience relating to how the negative effects for production and products could be minimised or even overcome through adapted technical treatment and processing through-out the forestry wood chain.

This activity aims to close the gaps in knowledge by an integrated approach on a European level.

Technical Approach

Laboratory analysis of small wood samples and experimental industrial-scale processing will be carried out on well-defined experimental trees showing stress phenomena coming from stands with significantly different site conditions and silvicultural history.

High quality sawn timber, rotary cut and sliced veneer will be produced under controlled conditions. The detection, evaluation and prevention of stress and its negative impacts on the quality of beech timber and related products will be investigated, analysed and evaluated at all stages of the chain from forest to the end products.

Through the exchange of data, methods and material, the variance of the beech resource throughout central Europe will be investigated.

Expected Results

The results will help to minimise the negative effects in the short-term by stress-adapted treatment and processing, and in the long-term by modifying silvicultural practise, aiming at a reduction of growth stresses.

Cracked stem of beech wood (as a consequence of internal stresses)

Sliced veneer with split, a problem that occurs
when working with stressed beech wood

Contacts

Coordinator

Albert Ludwigs Universität Rektorat GERMANY

EC Scientific Officer

Alexandros ARABATZIS / European Commission DG Research Theme 1 Key Action 5.3 / BELGIUM

Participant