Services and Equipment

Identification of wood species

Based on physical, mechanical and mainly macroscopical and anatomical analysis (light microscope, SEM, µCT,…) wood species can be identified. This service also relies on reference material available at UGent-Woodlab and e.g. also at the wood collection of RMCA (http://www.metafro.be/).

Analysis of decay and testing efficacy of wood preservatives

Until further notice, we do not identify decaying wood organisms (both wood rot and insect damage) or perform large scale fungal testing.

Structure: X-ray tomography

Nanowood is the latest multi-resolution X-ray tomography setup developed at UGCT. It consists of a stage combined with two X-ray tubes and two X-ray detectors, specifically designed to permit very high resolution scans as well as scans of larger objects. Reconstructed voxel size can be chosen arbitrarily ranging from 200μm to 400nm with maximal scan-efficiency. The combination of both tubes and two detectors covers all resolutions in an optimal way. The system offers a large range of operation freedom with an 8-axis motorized stage for sample rotation/magnification/positioning, tube and detector selection and tiling; all combined in versatile acquisition routines (standard or fast scanning, tilling, helix,...). This scanner can be used in any field of wood biology and technology. In the publication list of the lab, several papers refer to X-ray tomography. More information can also be found on the website of UGCT, the consortium of X-ray tomography UGent-Woodlab belongs to.

Structure: Cryo-SEM and SEM

The goal of cryo-SEM (Scanning Electron Microscope) is to vitrify the liquid phase with all the constituents thus preserving them in their natural and original state. Liquid N₂ (-210°C) is used for the fast freezing to minimize any damage ice crystals may cause. The sample can be fractured, etched and coated to expose internal microstructure. Cryo-SEM imaging with high resolutions (<100 nm) at UGent-Woodlab includes the study of ultrastructural wood cell features, which is highly relevant in tree biological (growth analysis), wood technological (material research) and biological degradation (both bacterial as well as fungal) contexts. The cryo-SEM also allows elemental imaging using a state-of the-art EDX detector. As such it is very complementary tool to our other set of imaging instruments, such as light microscopy, fluorescence microscopy and X-ray tomography. The cryo-SEM is available at the Department of Food Technology, Safety and Health within the Bio-imaging consortium, of which UGent-Woodlab is a partner.

An older JEOL JSM-T330A SEM Scanning Electron Microscope is available as well at UGent-Woodlab, for fast screening of samples.

Structure: Wood anatomical research

Wood is composed of different cell types and tissues. Wood anatomy is the discipline where different shapes, dimensions and functions of wood cells and tissues are examined. Particularly, wood anatomy is applied to identify woody species. To do so, small wood samples are pre-treated (cooked, impregnated...) and mounted on a sled microtome with a stainless steel knife. Next, thin sections are trimmed, dehydrated (alcohol) and fixated in synthetic or natural resin between two glass slides. Sometimes, thin sections are stained with colour agents before fixation in order to accentuate specific cell types. Finally, these thin sections are studied using transmitted light microscopy and fluorescence microscopy. UGent-Woodlab is equipped with a mechanic sled microtome, an electric sled microtome, reusable and non-reusable microtome knives, a knife sharpener, more than a dozen transmitted light microscopes (Leitz, Zeiss, Nikon), a fluorescence light microscope (Olympus Vanox), a reflected light microscope (Leitz Laborlux) and a large range of pre-treatment agents, colour agents and resins. UGent-Woodlab also has a modest xylarium, with a range of species from all around the world. The samples are conveniently stored in Milletia laurentii cabinets.

Structure: Dendrochronology

Dendrochronology or tree-ring dating is the scientific method of dating based on the analysis of patterns of tree-rings. It is an important discipline delivering information on tree growth and development, ecophysiology of trees, etc. The relation with climate is studied in what is called the research field of dendroclimatology, contributing to ourknowledge of how trees and tree communities react to a changing environment as trees can be considered as long-term archives of environmental changes. UGent-Woodlab disposes of a Lintab measuring system for cores or discs, with the accompanying TSAP software for recording, synchronisation and interpretation of results. The X-ray tomography scanner, discussed in this paper, is also used for dendrochronological purposes to quantify density at the microscale (microdensitometry), as such delivering valuable data. This last technique is especially useful when dealing with tropical trees with growth rings which are very difficult to discern. We also have an in-house imaging system for large surfaces (~60cm x 60cm) at high resolution (~5µm).

Service Life: Fungal testing

The resistance of solid wood or wood based materials against white rot and brown rot is tested according to European standards (CEN/TS15083-1/EN113, ENV12038). Preconditioning such as leaching (EN84) or evaporation (EN73) can be performed. UGent-Woodlab is equipped with two CTS cabinets. Test Basidiomycetes fungi as Coniophora puteana, Trametes versicolor, Poria placenta, Pleurotus ostreatus, Lentinus cyathiformis and Gloeophyllum trabeum are available.
Soft rot testing is also performed on a laboratory scale according to CEN/TS15083-2/ENV807. 
Field testing is performed with focus on EN 252 in ground and EN330 related accelerated above ground testing.
EN152 and an adapted version of BSI3900-G6 are applied to evaluate the susceptibility of wood coating systems, treated and untreated solid wood and wood based materials to blue stain (Aureobasidium pullulans) and moulds respectively. All fungi are maintained as required to retain their virulence.

Service Life: Accelerated ageing

To assess aesthetical changes and/or resistance against weathering of wood coating systems (EN927-6), solid wood or wood based materials artificial weathering is performed by means of an UV2000. Condensation cycles and specimen spray induces water initiated erosion or thermal shock. Different cycles can be programmed to mimic outdoor conditions in an accelerated way. Several research projects in the past have searched for the optimal settings in order to approach outdoor conditions as close as possible, avoiding to induce different damage patterns. Currently, the UV2000 is not operational, but can be re-initiated if need for longer term testing.

Service Life: General outdoor testing

The proof of the pudding is in the eating, which is the same for wooden materials. If wood is intended for outdoor use, there is need for outdoor testing and assessment. This is an example of an outdoor test-house consisting of a series of different wood species as well as different treatments (see a.o. the EU Life+ Silex project) that shows the potential of outdoor testing. The house is located in an urban area and is exposed to sun, rain and wind.

Materials: Bioenergy - Parr bomb calorimeter

The Parr bomb calorimeter with 1108 style oxygen bomb is a microprocessor controlled, isoperibol oxygen bomb calorimeter used for determination of the higher heating value (HHV) on samples weighing maximum 1,5g. The sample is put in a capsule and touched by a 10 cm long fuse wire. This is installed in the bomb, which is filled with oxygen, hung in a jacket with cooling water and connected with the ignition wires. The temperature change caused by ignition and sample burning is detected and used to calculate the HHV using the energy equivalent of the bomb and the sample mass. The HHV is corrected for nitric and sulphuric acid formation and the heat produced by the heating wire. The robust set-up of this equipment allows a straightforward analysis of the energetic content of a material and is therefore vital in research regarding bioenergy from lignocellulosic biomass.

Materials: Moisture dynamics 

Climatic test cabinets (CTS) or rooms are used to condition wood (solid, lignocellulosic fibres) using saturated salt solutions. 
Dimensional changes are measured using several tools from Mitutoyo (digital callipers, indicators, gauges, gage blocks,…).
This equipment is used to study moisture dynamics of wood species in relation to application and to qualify modified wood.

Materials: Treating plant (not active - future upgrade commissioned)

The laboratory treating plant of UGent-Woodlab consists of a standard vacuum pressure unit (30 cm diameter, 1.5 m long) complemented by smaller units for treatment with gas or developed to treat fibres. This equipment can be used for modification of wood or other lignocellulosic materials and for assessing treatability of timber and wood based panels.

Materials: Wood based panels laboratory press

For the production of (wood) composites a 60 by 60 cm programmable laboratory press is available at UGent-Woodlab (De Mets – Valmet).