Collapse-type Shrinkage in Plantation-grown Eucalyptus Cells When Subjected to Heat-steam Treatment

摘要

Collapse-type shrinkage in plantation-grown Eucalyptus cells is a bottleneck to severely restrict its high-effective utilization as environment-friendly solid-wood products. So, measurement of collapse-shrinkage parameters on seven species of Eucalypts (Eucalyptus urophylla, E.grandis,E.urophyllaxgrandis, E.grandis xurophylla, E. dunnii, E. cloeziana and E. pellita) have been carried out under three kinds of treated patterns (heating, steaming and combined treatment) by means of image analysis technique. The results indicated that the total shrinkage and residual collapse increase obviously with heating temperature and steaming time for five species of low-density eucalypts(E.urophylla, E.grandis, E.urophyllaxgrandis, E.grandis xurophylla and E. dunnii), while increase slightly for other two species of higher-density Eucalypts (E.cloeziana and E.pellita).Combined treatment has not made the total shrinkage and residual collapse take on the additive trend, especially for higher-density Eucalyptus. Therefore, the results will provide the important practical significance for the reasonable processing of plantation-grown eucalypt wood.