Properties of high density fiberboard mixed with poplar bark

Abstract

Formaldehyde in the indoor air is one of the chemicals which can cause health risk; therefore, researchers have strived to reduce formaldehyde emissions from different wood products. There are many chemical compounds in bark, including tannins, which can react with formaldehyde. The aim of this study was to reduce the formaldehyde emissions from HDF by mixing poplar bark powder into the raw material. 2, 4, 6, and 8 % (based on dry weight) Populus×euramericana bark was mixed with fibers, and HDF panels were manufactured with urea-formaldehyde resin. Mechanical properties, color change, and formaldehyde release were measured. Contrary to expectations, the mixed bark did not reduce formaldehyde emissions, but the mechanical properties deteriorated due to the bark powder. Formaldehyde emissions were reduced only in the case of 2 % added bark; in cases of 4, 6, and 8 %, the emissions increased.