Increasing permeability of spruce sapwood with enzymatic treatment

In this thesis, spruce wood (Picea orientalis L.), known as one of the refractory wood species, was treated with Bioprep 3000 L, Viscozyme L, Texazym BFE, and Texazym DLG, which are commonly used in the textile industry to increase permeability. Wood samples were treated with 0.5 %, 1 %, and 3 % concentrations of enzymes for 7, 14 and 28 days. The effects of the enzymatic treatment on the wood properties were examined with scanning electron microscopy (SEM) and light microscopy (LM). The changes in wood pore volumes were determined by mercury intrusion porosimetry. The retention and penetration values of wood samples impregnated with Celcure AC 500 were measured. The copper content in the wood was determined by means of inductive coupled plasma (ICP). The ICP analysis results showed that enzymatic treatment increased copper retention in the wood. In particular the copper retention of samples treated with 1 % concentration of enzymes for 7 days were significantly higher. The investigation by scanning electron and light microscopes revealed that pectin material on the pit surface was degraded through the enzymatic treatment. Accordingly, the opening of aspirated pits considerably increased wood pore volumes, retention and penetration. When the negative effects of enzymatic treatment were investigated, it was determined that the mass losses of the wood samples were negligible. Additionally, there was no noteworthy decrease in the enzyme treated wood's mechanical properties. Key Words: Celcure AC 500, Enzymatic treatment, Impregnation, Mechanical resistance, Pectinase enzyme, Wood permeability