Journal
WOOD MATERIAL SCIENCE & ENGINEERING
Volume 6, Issue 4, Pages 219-227Publisher
TAYLOR & FRANCIS LTD
DOI: 10.1080/17480272.2011.622411
Keywords
HEMI test; microscopy; resistance to impact milling; scanning electron microscopy; thermally modified timber
Categories
Ask authors/readers for more resources
Heat treatment of wood is an effective method by which to improve the dimensional stability and biological durability, but the mechanical strength is decreased at the same time. Besides chemical modification of cell-wall constituents, physical weakening of the microstructure owing to heat-induced defects may also contribute to strength loss. Therefore, anatomical properties of heat-treated beech (Fagus sylvatica L.) and spruce (Picea abies Karst.), studied by light microscopic and scanning electron microscopic analysis, and their interrelation with strength properties and structural integrity were investigated. For determination of structural integrity, the high-energy-multiple-impact (HEMI) test was applied. Microscopic analyses showed frequent formation of radial cracks in heat-treated beech close to the rays as well as tangential cracks in the latewood of spruce. In addition, the modulus of rupture was more affected by the heat treatments than the resistance to impact milling (RIM) determined by the HEMI test, because RIM is based on multiple fractures on the microlevel that are not affected by the formation of intercellular cracks or other defects due to the heat treatment. It was concluded that heat-induced defects in the wood microstructure contribute to the substantial strength loss of thermally modified timber.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available