Determining the effect of synthetic-based varnish and impregnation on wood’s shear strength under cold climate conditions

Abstract

Glue shear strength and wood preservatives play an important role in the longevity of engineered wood products. The effects of factors such as UV rays, humidity, and temperature on wooden materials are known. However, it is not known what effects sub-zero temperatures have on wood material and how wood preservatives play a role. This study determined the effects of synthetic-based varnish and impregnation on shear strength in cold climatic conditions. Variables including glue type, ambient temperature, tree type, and process type were investigated. Wood laminate test samples were produced for this purpose, and water repellent impregnation material and synthetic-based varnish were used as wood preservatives. Experimental samples were kept in a cold air cabinet at (-15 °C) and (-30 °C) temperature for 90 days. Samples kept in different temperature conditions were subjected to a pull experiment in a parallel (//) direction to the fibers under static load. As the ambient temperature decreased, the shear strength decreased (-15 °C: 8,960 N/mm2 ,-30 °C: 8,025 N/mm2 ) . When the performance of wood preservation elements were examined, it was determined that the varnish process (8,875 N/mm2) and the impregnation process (8,691 N/mm2) were not statistically significant, at 12% and 10%, respectively.