WOOD WISE
DELAMINATION
Both the CCA and boron treated delamination test blocks met the requirements of EN 14080 ( 2013 ), as the average total delamination did not exceed 10 % in length in any of the groups ( Figure 2 ), with 4 % CCA showing the highest total delamination out of all the concentration levels tested ( Figure 3-left ). The 1.68 % boron treated samples were found to have a better
resistance to delamination in comparison to 4 % CCA treated samples . As expected during impregnation cycles it was observed that boron leached out of the test blocks ( Figure 3-right ). This was due to the high-water solubility of boron , which limits the use of DOT as it cannot be used to treat wood products exposed to exterior conditions or frequent wetting or areas of high moisture content .
Figure 2 : The total delamination of CCA and boron ( DOT ) treated blocks was far lower than the 10 % limitation according to the European standard EN 14080 .
Figure 3 : CCA treated delamination sample , after three impregnating cycles ( left ), leaching out of boron ( DOT ) in delamination test sample ( right ).
CONCLUSION
The results highlight that South African pine timber treated with CCA ( 2 % and 4 %) and DOT ( 1.67 % and 3.3 %) and bonded with a one-component PUR adhesive can be successfully used to produce engineered wood products as the shear strength and delamination test results met the EN 14080 ( 2013 ) standard requirements .
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