The use of wood and wood products as building material strongly depends on their material, processing and use properties. The group «Wood Technology/Surface Technology» is involved in the analysis and the improvement of these properties in the fields of wood physics and mechanical technology as well as regarding weathering protection and adhesive bonding. A special focus is put on the wood surfaces, where the primary interaction with other materials and the environment takes place. The activities range from «forest oriented» wood research (forestry – wood chain, interface forest – wood processing) to the use characteristics of assembled wooden components and thus cover the wide area from raw-material to end-use applications.

Flyer (PDF)

Properties and utilisation of native wood species

• Physical and mechanical properties of wood and wood products (wood quality, grading)
• Properties and potential use of less-exploited (native) wood species or grades (e.g. Sweet chestnut)
• Modified wood (e.g. Thermowood, Bioincising)
• Improvement of wooden components and products (e.g. windows, façade cladding, flooring elements)

Weathering protection

• Protective surface treatments of wood and wood products (effectiveness, durability, environmental impact)
• Nanotechnology for surface protection / Functionalised wood surfaces (e.g. hydrophobisation)
• Moisture-related processes in (weather exposed) wooden components

Adhesive bonding

• Moisture- and temperature resistance (reliability)
• Application of coupling agents for the adhesive bonding of wood
• Effect of wood extractives on bond quality
• Rehabilitation of adhesive joints
• Quality control

• Mechanical and moisture-related material tests (solid wood, wood-based materials, composites)
• Microscopy of biological materials (light microscopy, SEM, TEM, UV-microscopy, partly with elemental analysis)
• Surface characterization:
  - visual assessments, microscopy
  - Colour, gloss
  - Topography, roughness
  - Hardness
  - Wetting behavior (contact angle, surface energy)
• Coatings:
  - Film structure, film thickness
  - Adhesion
  - Natural und artificial weathering tests (EN 927)
• Adhesive bonding:
  - Mechanical tests of bond line integrity (e.g. EN 205, EN 302-1, EN 392)
  - Delamination (e.g. EN 302-2, EN 391)
• Special methods:
  - Dynamic vapour sorption (DVS)
  - Dynamic mechanical analysis (DMA)

• R&D projects
• Material tests / characterisation
• Damage analysis
• Expert's reports
• Consulting

Contact: Martin Arnold

Weathering protection of wood surfaces

Modern wooden constructions require - particularly for façades - visually attractive and durable surface coatings. However, various problems regarding the surface protection of weather exposed wood are still not satisfactorily solved and the durability is principally limited. In several research projects in cooperation with industrial partners new concepts and functionalized treatments (partly based on nanoscaled components) for an improved moisture, UV and biological protection are developed and their long-term durability is tested.

Currently three specific surface-related projects are running within the frame of NRP66 'Resource Wood': www.nfp66.ch

- Modified nanofibrillated cellulose in surface coatings (Link to project description http://www.nfp66.ch/E/projects/wood-material-for-components/cellulose-nanofibrils-wood-coatings/Pages/default.aspx )

- Wood surface functionalisation using photoinitiators (Link to project description http://www.nfp66.ch/E/projects/wood-material-for-components/wood-surface-functionalisation-photoinitiators/Pages/default.aspx )

- Development of a natural UV-protection of wood surfaces by cellulose-rich layers (Link to project description http://www.nfp66.ch/E/projects/wood-material-for-components/natural-uv-protection-wood-surfaces/Pages/default.aspx )

We also participate in the running COST-Action FP1006 'Bringing new functions to wood through surface modification'. (Link: http://cost-fp1006.fh-salzburg.ac.at/ )

Contact: Martin Arnold, Tina Künniger

Properties and utilization of modified wood

Wood as a 'natural' material exhibits properties, which depending on the application are unwanted (e.g. hygroscopicity, limited durability). By various modification processes it is possible to purposefully change selected wood properties. Thus, new types of wood based materials emerge, whose properties markedly differ from the starting material. For successful applications of modified wood, its distinct properties have to be studied and considered.
Currently the heat treatment of wood is a particularly popular method, which can considerably improve the dimensional stability and durability. While in Scandinavia mainly softwoods are heat treated, in middle Europe also hardwoods are used. In a series of projects we particularly explore the properties of heat treated beech wood.

Wood quality, conservation and utilisation of windblown timber

Two hurricans within the last 15 years have caused considerable damage in the Swiss forests. Several research projects were dealing with the susequent timber utilization problems, particularly regarding log conversation and mechanical damages in the harvested timber. The overall objective of the projects was to compile decision helps to cope better with future damage events.

Contact: Martin Arnold
Detailed Information (in German only)