Spring-back of Wood after Longitudinal Compression

Longitudinal compression of natural wood makes it easier to bend. Fixation after compression results in improved changes in the properties of this environmentally friendly material. The usage of this modified wood helps to make curved wood products with much less waste, without chemicals. Using 20% compression ratio followed by fixation for 1 minute results in optimal properties for laboratory investigations. As a result of this treatment, oak wood is shortened averagely by 3.84% due to its natural spring-back ability. The aim of this study is to determine not only the level, but the duration of spring-back of wood after its longitudinal compression. Wood remains always a living organism with a natural structure, actively responding to environmental conditions such as temperature and humidity of the air. Its moisture content follows the circumstances and changes its properties, for example, it shrinks when its moisture content decreases. Longitudinal compression (aka pleating) multiplies the dimension change of wood in its longitudinal direction, compared to untreated wood. In this study, the remaining shortening of pleated wood was averagely 5.50% after spring-back and drying shrinkage.