Influência do diâmetro e umidade no tratamento preservativo de moirões de Eucalyptus

Abstract

The aim of this study was to assess the effects of diameter class, general moisture and sapwood moisture over the retention of CCA-C (Chromated Copper Arsenate type C) on a Eucalyptus urophylla clone wood preserved in autoclave. 36 fence posts were used, belonging to the diameter classes of 7, 9, 11 and 13 cm, which were separated and exposed to three outdoor drying times: 20, 40 and 70 days. The pre-treatment moisture values, general and only sapwood, were determined by diameter class and drying times. After the preservation in autoclave, the treatment quality control was made by analyzing the CCA-C retention. Retention in fence posts of the 7 cm class was higher than those of 9, 11 and 13 cm classes, which did not vary statistically amongst each other. The increase in drying time from 20 to 40 days resulted in significant increase in average retention from 5.70 to 6.67 kg A.I.*m-3. The mean variations of the general moisture and the sapwood were significant with variation of retention, showing good correlation between the factors. The correlation between the fence posts general moisture and retention of CCA-C (r = -0.86) was stronger than the correlation between sapwood moisture and retention (r = -0.70).