: Buchholzer, P.

Abstract
It is supposed that the acid hydrolysis taking place during the thermal-mechanical disintegration is accelerated by the use of recycling water influencing the fibre properties and as a result also the bonding quality of the MDF. Thus, mainly the influence of the recycling of condensation products at the fibre production on the properties of MDF made from different wood species (poplar, beech, spruce, pine) was investigated. The properties of MDF bonded with urea resin were hardly influenced by the recycling of condentation products. The differences in the chemical fibre properties are too slight as to significantly influence the bonding quality of the boards. Therefore, recycling water can be used for the fibre production without any negative effect on the quality of MDF.