Bleaching treatments for blue-stained lodgepole pine affected by the mountain pine beetle Dendroctonus ponderosae

Abstract

A range of bleaching agents were screened to determine the bacteria that is most effective at removing the blue stain of the pine timber and then the most efficient bleaching agent was optimized. Kiln dried, blue stained lodgepole pine wood was screened and bleached by sodium hypochlorite, sodium hydroxide, followed by 30% hydrogen peroxide, sodium chlorite, and urea. Solutions were blushed onto the sapwood and heartwood of 6 replicate samples at a level of 0.012mL/cm2, and the samples were then conditioned at 20°C and 65% rh for 1 week. The samples were air dried for 24 hours, rinsed with 400mL of water and then conditioned for 48 hours. The color of the bleached wood was measured with a spectrophotometer and is expressed using CIElab parameters. The results show that the sodium hypochlorite is effective at removing the blue-color from blue-stained wood, and there is a positive relationship between solution concentration and effectiveness of the treatment. Show more