The Decay Resistance Properties of P. Ussuriensis Kom Lumber Impregnated with Preservative by Roller-Compression

Abstract

Waterborne preservative of DDAC and boride are used to impregnate P. ussuriensis Kom lumbers by roller compression under compression rates ranging from 10 percent to 50 percent. Results showed that the cranny in intervascular pit membranes appeared, and the cell wall of vessel element and fiber segment displayed drape and cranny due to roller compression. With the rise of compression rate, both the penetration depth of preservative and the retention quantity of preservative in the experimental lumber increased, while the mass loss rate decreased.The penetration depth perpendicular to the grain was more than 3.9 mm, while that parallel to the grain of wood was more than 20 mm when the compression rate was greater than or equal to 30 percent. Under the compression rate of 30 percent, the retention quantity of preservative in the experimental lumber impregnated with DDAC (thickness of 1 percent) was 8.743 kg/m3 and the mass loss rate was 14.36 percent, while those with boride (thickness of 2 percent) are 3.322kg/m3 and 9.92 percent.