Anmerkungen:
Besteht aus Sonderabdrucken aus verschiedenen Publikationen
Beschreibung:
As solid wood, Norway spruce (Picea abies (L.) Karst.) is used in a wide range of applications for interior and exterior situations. Due to its low natural durability against wood decay fungi, a treatment with wood preservatives is necessary for certain applications. In addition, there is a growing interest for treatment with waterborne surface modification substances that specifically improve selected wood properties of Norway spruce such as UV-resistance, hydrophobicity, hardness and fire resistance. The impregnation with such substances requires often a wood permeability that allows a sufficiently deep and homogenous distribution of the substances in the wood in order to obtain an efficient wood property improvement. However, Norway spruce wood is known to have a low permeability which is related mainly to the aspiration of bordered pits during wood drying. In the living tree, permeability is mainly determined by the bordered and half bordered pits that constitute the interconnecting voids between the tracheids and the xylem ray parenchyma. During wood drying, most of these pits get irreversibly closed due to the aspiration of the flexible pit membranes. The resulting low impregnability complicates treatment of Norway spruce with liquid preservatives or wood modification substances ...