DETERMINATION OF THE FRACTURE-TOUGHNESS O F MDF BOARD

Fracture toughness is a measure for the crack resistance of a material . This paper presents the results of an analysis on the influence of d ensity and moisture content on fracture toughness of MDF. Fracture tou ghness was measured using ASTM E 399 with CT-specimens (parallel to th e board direction). Acoustic emission analysis and scanning electron m icroscopy (SEM) were used to assess the kind of fracture and the fract ure surface. Higher fracture toughness values were found with increasi ng density. An increase in moisture content caused a decrease in fract ure toughness. Acoustic emission analysis showed no clear results rega rding the kind of fracture of MDF. According to SEM fibres were nearly torn out of the MDF board. Fractures of fibres, as they occur in part icleboard, were not observed.