The effect of cyclic relative humidity exposure, sanding and grooving on the dimensional stability of solid wood parquet

Abstract

In this study, the effect of cyclic relative humidity changes, sanding and grooving on the dimensional stability of solid wood parquet were evaluated. The experiments were carried out on oak (Quercus petraea) and sapele (Entandrophrag-ma cylindiricum) wood species. Firstly some physical tests (density, shrinkage, and swelling) were carried out on 20×20×30 mm specimens obtained from these two species. After the physical tests the parquet size specimen groups were obtained both in radial and tangential section directions and in two sizes; narrow (250×50×15 mm) and wide (250×90×15 mm). One group of parquet size specimens was sanded and the other group was grooved. There was also a group of specimen for control. After being conditioned to equilibrium moisture content at 65% relative humidity, specimens were placed in a climate chamber and exposed to cyclic relative humidity changes. The dimensions of the specimens were measured between different environmental conditions and the dimensional change was evaluated by taking into consideration the mentioned physical properties. The results show that cyclic relative humidity changes mainly resulted with an increase in the dimensional stability of sanded and cyclic conditioned specimens. There was not a significant change in the dimensional stability of grooved specimens.