TY - JOUR
T1 - Visualization and numerical analysis of adhesive distribution in particleboard using X-ray micro-computed tomography
AU - Evans, Philip D.
AU - Morrison, Olivia
AU - Senden, Tim J.
AU - Vollmer, Stephan
AU - Roberts, Ray J.
AU - Limaye, Ajay
AU - Arns, Christoph H.
AU - Averdunk, Holger
AU - Lowe, Adrian
AU - Knackstedt, Mark A.
PY - 2010/12
Y1 - 2010/12
N2 - X-ray micro-CT is used here to visualize the distribution of melamineureaformaldehyde adhesive in the wood composite, particleboard, and examine changes in adhesive distribution on wood particles (flakes) before and after pressing. CT and scanning electron microscopy of unpressed, wax-covered, wood flakes reveals that adhesive is evenly distributed on flakes, although it does not completely cover all surfaces. Adhesive on these wood flakes migrates during pressing forming more continuous glue-lines in areas of the composite where flakes are pressed closely together and more discontinuous glue-lines where inter-particle contact is poorer. Adhesive accumulates in small, but not very large voids, and also in cracks in wood flakes and around very small wood particles. These observations accord with previous observations of adhesive distribution in pressed wood composites. In addition, CT reveals that resin accumulates in capillary channels within the splintered ends of wood flakes and at the base of composite samples. The orthogonal variation in volume of the composite occupied by adhesive, wood and void space was quantified using maximal sphere modelling, and anisotropy in the distribution of these phases in the x, y and z directions was quantified using chord length analysis. These numerical techniques reveal that adhesive is more closely associated with wood flakes than void space, despite its tendency to migrate during pressing. As a result, adhesive is mainly aligned in the same xy direction as wood flakes forming an anisotropic discontinuous network. We conclude that X-ray micro-CT is a powerful tool capable of providing new insights into the distribution of adhesive in wood composites.
AB - X-ray micro-CT is used here to visualize the distribution of melamineureaformaldehyde adhesive in the wood composite, particleboard, and examine changes in adhesive distribution on wood particles (flakes) before and after pressing. CT and scanning electron microscopy of unpressed, wax-covered, wood flakes reveals that adhesive is evenly distributed on flakes, although it does not completely cover all surfaces. Adhesive on these wood flakes migrates during pressing forming more continuous glue-lines in areas of the composite where flakes are pressed closely together and more discontinuous glue-lines where inter-particle contact is poorer. Adhesive accumulates in small, but not very large voids, and also in cracks in wood flakes and around very small wood particles. These observations accord with previous observations of adhesive distribution in pressed wood composites. In addition, CT reveals that resin accumulates in capillary channels within the splintered ends of wood flakes and at the base of composite samples. The orthogonal variation in volume of the composite occupied by adhesive, wood and void space was quantified using maximal sphere modelling, and anisotropy in the distribution of these phases in the x, y and z directions was quantified using chord length analysis. These numerical techniques reveal that adhesive is more closely associated with wood flakes than void space, despite its tendency to migrate during pressing. As a result, adhesive is mainly aligned in the same xy direction as wood flakes forming an anisotropic discontinuous network. We conclude that X-ray micro-CT is a powerful tool capable of providing new insights into the distribution of adhesive in wood composites.
KW - Composites
KW - Microscopy
KW - Wood
KW - X-ray micro-computed tomography
UR - http://www.scopus.com/inward/record.url?scp=77957705834&partnerID=8YFLogxK
U2 - 10.1016/j.ijadhadh.2010.08.001
DO - 10.1016/j.ijadhadh.2010.08.001
M3 - Article
SN - 0143-7496
VL - 30
SP - 754
EP - 762
JO - International Journal of Adhesion and Adhesives
JF - International Journal of Adhesion and Adhesives
IS - 8
ER -