PERMANENT FIXATION OF COMPRESSIVE DEFORMA TION OF WOOD BY CROSS-LINKING

One of the methods to permanently fix the compressive deformation of w ood is to form crosslinking between the wood components in a deformed state. To confirm this, vapor and liquid phase formalizations were inv estigated. The compressed wood was treated with tetraoxane (cyclic tet ramer of formaldehyde) and SO2 (catalyst) in a dry condition at 120 de grees C for 2 hours. The deformation was fixed perfectly even after bo iling in water for 8 hours. The same results were obtained by the reac tion at 135 degrees C for 20 minutes with SO2 and formaldehyde vapor g enerated from paraformaldehyde. However, the deformation was recovered by soaking in a H2SO4 water solution. From these facts it may be conc luded that permanent fixation through formalization is ascribed to the formation of crosslinking between wood components. By vapor phase for malization, mechanical properties remained almost unchanged. On the ot her hand, the complete fixation was not realized by liquid phase forma lization, although the recovery of set decreased with increasing treat ing time.