软化处理对桉木刨切单板质量的影响

为改善刨切厚单板质量,减少水热处理时间,采用带实时喷蒸加热功能的刨切试验装置,在冷水浸泡、冷水浸泡再喷蒸加热、水煮软化和水煮软化再喷蒸加热4种条件下对桉木进行刨切试验,刨切厚度为1~6 mm。结果表明:单板表面粗糙度为4.29~14.30μm,随刨切厚度的增加而增加,其中横纹方向表面粗糙度大于顺纹方向,但都能满足GB/T 13010—2006的要求;单板背面裂隙度在刨切厚度为2~6 mm时变化幅度不大。相对于未喷蒸加热的情况,采用实时喷蒸加热刨切的单板横纹表面粗糙度、顺纹表面粗糙度和背面裂隙度的最大降低百分率分别为11.55%、23.12%和28.06%,表明采用实时喷蒸加热处理对改善单板质量效果明显;其中,在水煮软化再喷蒸加热的条件下,刨切单板表面粗糙度和背面裂隙度最小。

Effect of Softening Treatment on the Quality of Eucalyptus Sliced Veneer

In order to improve the quality of sliced thick veneers and to reduce the hydrothermal treatment time,a veneer slicer with the function of real-time steam injection heating was used for slicing experiment of eucalyptus.This experiment was conducted under the four kinds of softening conditions,namely,soaking in cold water,steam heating after soaking in cold water,water-boiling and steam heating after water-boiling.The surface roughness of veneers were 4.29-14.30 μm,and increased gradually with the increase of slicing thickness,the surface roughness perpendicular to grain was larger than that parallel to grain,but all of them could meet GB/T 13010-2006.The change of back clearances tended to be smooth when the slicing thicknesses were 5-6 mm.Compared with the condition of non-steam heating,the quality of veneers sliced with real-time steam heating could be improved obviously,and the maximum reducing percentage of surface roughness perpendicular to and parallel to grain and back clearance were 11.55％,23.12％ and 28.06％,respectively.The surface roughness and the back clearance of veneers were both the smallest under steam heating after water-boiling.