VOLUME 60, ISSUE 2/2019

The research project "Emission and impact measurements of odours in a plant of the wood-based panels industry", which was awarded by the German Federal Environmental Agency (FKZ 3715 51 307 0) within the framework of the German Federal Ministry for Environment, Nature Conservation, Building and Nuclear Safety, is intended to explain the correlation between increased emission concentrations with simultaneously reduc-ed emergence of complaints, and thereby contributing to a specification of a control system for odour emissions from facilities of the wood-based panels industry. To sum it up, there is a good conformity between the odour impact prediction (dispersion calculation) on the basis of the emission measurements and the measured values of the odour in ambient air. Despite the fluctuation in the measured odour emissions, it was possible to make comprehensible and plausible predictions about the actual facility-related odour pollution in the investigated area of the plant chosen for the analysis by means of odour impact predictions.

The component testing of wood constructions for mechanical engineer-ing applications is an essential part of the development and optimization process. Due to the wide scattering of the mechanical characteristics and the many influencing factors on the mechanical properties of wood veneer composites, a reliable calculation is often inadequate. Test methods with high information density are advantageous in order to minimize the number of samples and the time of the tests. The analysis options and essential results of a static-dynamic component test by load-increase test are shown on the example of a load handling device made of wood veneer composite.

For an optical embellishment, design elements are taped onto furniture’s surfaces. To prevent these elements from falling off, a sufficiently high surface energy of the finish-lacquers is needed. The influence of the process parameters on the curing and the pressing process on the durability of the taped design elements was investigated on two electron beam-cured lacquers. The dependence of these parameters was discussed and compared to the properties of four acid-hardening systems. For this comparison, the surface energy was considered as the main criterion. The pre-trial, in which the process parameters were gradually varied, showed that the surface energy is independent from the crosslinking-level and the curing parameters. However, the durability was influenced by the curing parameters, which leads to the assumption that the curing-level has an essential influence on the durability of taped design elements on electron beam-cured lacquers.

Nowadays, alternatives to fresh wood and urea-formaldehyde resins as a synthetic adhesive system and other fossil origin adhesive systems are required. Wood waste materials are normally used for biofuel production or waste incineration. From environmental perspective, it is favorable to recycle wood material and use the concept of multiple sequential use than just burning it for short-term energy production. The objective of this study was to investigate the feasibility of manufacturing animal’s albumin-protein resin-bonded particleboard from wood waste comply with the European standard EN 312 (2010). In this study, untreated wood waste material (type AI) was used to produce three-layered particleboards bonded by animal’s albumin-protein resin. The particleboard was produced with a target density of 640 kg/m³ and the mechanical and physical properties were analyzed and in addition, the extractable formaldehyde content and formaldehyde release of the particleboards were characterized as well. The results point out that it is possible to manufacture three-layered animal’s albumin-protein resin bonded particleboard based on recycled untreated wood waste material (AI) that complies with the European standard EN 312 (2010) where the mechanical and physical properties as well as extractable formaldehyde content of particleboards achieve the requirements of European standard EN 312 (2010) for particleboards almost fully type P2 and type P1. Furthermore, the formaldehyde release (3 h and 24 h) of particleboards achieve the requirements of European standard EN 312 (2010) for particleboards emission class E1. Moreover, animal’s albumin-protein resin-bonded particleboard based on wood waste can be considered as ultra-low formaldehyde release particleboard.

Interest in utilization of hardwoods for glued structural timber products like glued laminated timber and cross-laminated timber is increasing due to external factors such as shifting availability of softwoods and hardwoods and rising demand for timber in the building sector and favourable mechanical properties of hardwoods. In an orienting study, 83 beech boards sawn from 17 logs and 109 ash boards originating from 14 logs were examined. Dynamic measurement of modulus of elasticity for the logs as well as for the boards at different processing stages was performed, and the boards were visually strength-graded according to DIN 4074-5 (2008) and tested in tension according to EN 408 (2012). With regard to pre-grading of logs by dynamic measurement, the results seem promising for both tested hardwood species, with good correlations between log and board stiffness observed. In contrast, the relationship between tensile strength and static modulus of elasticity in tension was found to be lower compared to spruce. For the beech sample it was still moderately strong, but for the ash boards only a weak correlation was observed. The frequent occurrence of pith strongly affected the result of visual grading and the pith might even have more adverse influence on the yield of high-strength boards than the knottiness. The application of internal log scanning for sawing optimization might be a key to an efficient production of structural boards from hardwoods.

3D printing using renewable resources can provide opportunities to produce individual parts made from bio-based materials. A variety of raw materials such as wood flours from different sources and materials similar to wood, such as Miscanthus and apricot stone flour are processed in combination with a suitable binder. Several applications are emerging from this, for example packaging of fragile prototypes with an individual package made from Miscanthus. A further potential application is the production of models such as architectural models from wood flour. Using renewable raw materials, which are partly even waste materials of industrial processes, guarantees sustainability of the created parts.