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1995
Journal Article
Titel
Zerstörungsfreie Festigkeitsuntersuchungen an Spanplatten mit Ultraschallmeßtechniken
Alternative
Nondestructive strength evaluations of particleboards using ultrasound measuring techniques
Abstract
The wood properties (high damping, anisotropy) play an important role for the ultra-sonic examinations of wood and wood-based materials. Ultra-sonic examinations of strength and defects are possible for solid wood but complicated due to the difficult coupling of probes to specimen. Informative investigations were carried out on three-layer laboratory particleboards with a modified ultra-sonic test device (type: USIP, manufacturer: Krautkrämer) as well as on an appropriate plant for the detection of defects (delamination) (type: UPU, manufacturer: GreCon). There, correlations turned up between the tensile strength and the sound velocity when coupling the probes to specimen in contact. Non-contacting scanning of boards with the fault (delamination) detection plant revealed a certain influence of pressing time and board temparature on the signal amplitude in the ultra-sonic receiver, however, it did not show meaningful correlations with the internal bond strength.