Optimizing the utilization of harvested wood products for maximum greenhouse gas emission reduction in a bioeconomy: A multi-objective optimization approach.

Climate change mitigation in a bioeconomy can be attained by increased use of harvested wood products. Thereby, substitution effects can contribute to reducing the Global Warming Potential, and storage effects can prevent direct carbon emissions to the atmosphere. Substitution and storage effects are often only considered as marginal changes.

Oak wood drying: precipitation of crystalline ellagic acid leads to discoloration.

Oak heartwood usually darkens during and after drying. This darkening can be heterogeneous, leaving noncolored areas in the wood board. These light discolorations have been linked to heterogeneous distribution of tannins, but compelling evidence on the microscale is lacking.

Facile preparation of superhydrophobic wood surfaces spraying of aqueous alkyl ketene dimer dispersions.

The prevention of excessive water uptake in wood in order to avert discoloration, swelling and decay is a major challenge for wood-based applications. We developed a facile surface treatment to protect wood from liquid water uptake that does not require harsh process conditions or toxic solvents. Water-based and surfactant-free dispersions of sub-micron alkyl ketene dimer wax particles were prepared and sprayed onto wood substrates.

Simultaneous change of wood mass and dimension caused by moisture dynamics.

An investigation of simultaneous dynamic mass and length change measurement for wood is presented. In contrast to the equilibrium in moisture content and swelling and shrinking, where extensive data exists for different wood species, less information is available for the dynamics of moisture changes in direct comparison to the related dimensional changes during the sorption process. This is due to a lack of methods.

Suitability of Different Variants of Polyethylene Glycol Impregnation for the Dimensional Stabilization of Oak Wood.

The common method to impregnate wood with polyethylene glycol (PEG) is to store the samples for several weeks in aqueous PEG-solution, allowing for diffusion of PEG into the wood. As this method is poorly suited for industrial application, an alternative approach based on vacuum-pressure treatment is evaluated in the present study. Using European oak wood and three variants of PEG, including silane-functionalized PEG, impregnation experiments at different PEG concentrations were performed.

Strain Measurements within Fiber Boards. Part I: Inhomogeneous Strain Distribution within Medium Density Fiberboards (MDF) Loaded Perpendicularly to the Plane of the Board.

Internal bond strength testing is a widely used approach for testing quality traits of wood based panels. Generally, failure of internal bond specimens is due to adhesion and/or wood failure in the specimen. It has been reported that a composite product with a large variation in the vertical density profile fails in the center part of the board which is either the middle of the core layer or the transition zone between core layer and face layer.

Digital image analysis of radial shrinkage of fresh spruce (Picea abies L.) wood.

Contact-free digital image analysis was performed of the radial shrinkage of fresh, fully saturated small spruce wood beams. An experimental test set-up was developed to ensure constant distance from the charge-coupled device camera to the sample surface as well as constant climate and light conditions during the whole experiment. Dimensional changes were observed immediately after the drying process began.

Cellulose nanofibrils as filler for adhesives: effect on specific fracture energy of solid wood-adhesive bonds.

Cellulose nanofibrils were prepared by mechanical fibrillation of never-dried beech pulp and bacterial cellulose. To facilitate the separation of individual fibrils, one part of the wood pulp was surface-carboxylated by a catalytic oxidation using (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) as a catalyst. After fibrillation by a high pressure homogenizer, the obtained aqueous fibril dispersions were directly mixed with different urea-formaldehyde-(UF)-adhesives.