Developing Highly Dimensionally Stable Multi-Layered Oriented Strand Board from Acacia Mangium Willd. Impregnated with Low Molecular Weight Phenolic Resin
This study was carried out to investigate the effectiveness of pre-treatment of wood strands with low molecular weight phenol formaldehyde (LPF) resin to improve the dimensional stability of oriented strand board (OSB). The origin and extent of thickness swelling (TS) in OSB made from A. mangium...
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| Format: | Thesis |
| Language: | English English |
| Published: |
2002
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/10107/1/FH_2002_13_A.pdf http://psasir.upm.edu.my/id/eprint/10107/ |
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| Summary: | This study was carried out to investigate the effectiveness of pre-treatment of
wood strands with low molecular weight phenol formaldehyde (LPF) resin to improve the
dimensional stability of oriented strand board (OSB). The origin and extent of thickness
swelling (TS) in OSB made from A. mangium Willd. were also investigated. Three- and
five-layered OSBs were fabricated with 5% resin solid based on oven dry weight of wood
strands (w/w) of phenol formaldehyde (PF) resin as a binder.
The origin of TS was determined by using coating method where the edges and
surfaces of the panel were coated with oil-based pigmented paint. To assess the degree of
TS, the OSB specimens were sliced/sectioned into four layers through the thickness
direction of the panel and were subjected to 24 hours of cold water soaking. The results
showed that the water uptake by the panel occurred mainly through the four edges. The
board surfaces absorbed 20% more water than those in the core. The distribution of TS
and water absorption (WA) for the sectioned layers were found to resemble that of the vertical density profile of the OSB panel. The surface layers of the panel had relatively
higher density, thus contribute significant influence over the TS of the board. The
Pearson ratio showed a very high correlation between the board density and TS (R2 =
0.87 and 0.96 for three- and five-layered OSB, respectively). The untreated five-layered
OSB (control) was found to be more stable than that of three-layered due to the presence
of higher resin content in the surfaces (fine particles). |
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