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Insulation materials have the potential to alter the fire resistance of timber frame assemblies. At present. Eurocode 5 Part 1-2 provides a model for the fire design of the load-bearing function of timber frame assemblies with cavities that are completely filled with stone wool. An extension of this model for glass wool in a post-protection phase has been published in the European Technical Guideline for Fire Safety in Timber Buildings. However, very little is known about the protection afforded by other insulation materials. This paper provides an overview of a study whereby model scale tests were performed with nine different insulation materials. The results of model scale furnace tests showed that the development of a 300° C isotherm on wood-insulation interfaces could be an indicator of the fire protection given by these insulations. Based on these findings, three different levels of fire protection with batt-type insulation materials are proposed. In this paper the most sensitive parameters that describe the protection against charring given by different insulations are analysed. The study offers some important insights into the concept of a new design model for the fire resistance of timber frame assemblies. [ABSTRACT FROM AUTHOR]

Thermally modified (TM) wood production has significantly increased in the last decade. The trend for TM wood residues should be similar – rapidly increasing, which has prompted this research on the possible efficient uses of these residues, such as sawdust. One of the possibilities could be the production of wood plastic composites (WPCs). In this work, three different hydrothermal modification regimes were used to modify birch boards. Modified and unmodified birch boards were milled to obtain sawdust. WPCs were made with a two-roll mill, and they consisted of 50 wt-% wood fibres + 50 wt-% polypropylene. Melt flow index (MFI), flexural properties, impact strength, microhardness water absorption and dimensional stability were tested. WPCs with TM wood showed improvement in flexural properties, MFI and other properties, however there was a decrease in impact strength. Scanning electron microscopy pictures of impact strength samples fracture surfaces were taken. [ABSTRACT FROM AUTHOR]

This paper presents the European initiatives, strategies, and directives that must be considered in future development of thermally modified timber and when optimising the existing, commercialised processes and discusses the next steps in developing thermally modified timber needed to meet the requirements of the European low carbon economy. The standards for assessment of environmental impacts of processes and products with the focus on Environmental Product Declarations (EPDs) for materials used in the built environment are presented and followed by discussion about the need to consider the environmental impacts on sustainably aspects of thermally modified timber. This includes: determination of environmental impacts of processing and resulting products; design of processes and products towards minimal environmental impacts; and acquisition of EPDs and of Product Category Rules (PCR) for products of thermally modified timber. [ABSTRACT FROM AUTHOR]

A large number of different heating technologies has been put into use for industrial scale thermal modification of wood. A useful classification of these processes is by the level of water vapour pressure, which ranges from vacuum to high saturated steam pressures. Only high water vapour pressure systems can maintain a finite moisture content during the heat treatment, but little is known about the water vapour pressure dependence of the thermal modification chemistry and the resulting modified wood properties. It is concluded from our analysis that the thermal wood reaction chemistry at the molecular functional group level is quite independent of the process and wood species. Wood properties that are strongly determined by wood chemical composition, such as the fungal durability and the equilibrium moisture content (EMC), can hence be equally achieved by all processes and for all wood species. This finding cannot be transferred to every other thermally modified wood property. [ABSTRACT FROM AUTHOR]

Oligomers of lactic and glycolic acid (OLA, OGA) and poly(butylene succinate/adipate) (OBS, OBA) were impregnated and heated into wood for dimensional stabilisation. These bio-polyesters variously provide bulking and lumen filling treatments. Solvent extraction of treated wood showed that ca. 50% of the polymer remains in wood with in situ polymerisation evidenced by GPC. OGA readily penetrates the wood cell wall, which occurred only on heating OLA, whereas OBS/OBA was lumen filling with any cell wall penetration only evident after water soaking. Stability of OLA/OGA treated wood was improved, but did not withstand extended leaching, whereas OBS/OBA treated wood presented higher stability once leached. Bending resistance was influenced by OLA/OGA treatments, but original MOE values were recovered after leaching. Overall, the results show the bio-polyester treatment can confer specific properties of the modified wood to suit selected end use applications. [ABSTRACT FROM AUTHOR]

This paper examined the effect of temperature of pressing on the strength of width glued elements during the process of production of solid wood panels. It has been used the polyvinylacetate D3 adhesive and solid beech wood ( Fagus silvatica ). Time of pressing has been determinate separately for each level of temperature of bonding, which amounted to (30 o , 40°, 50°, 60°, 70 o C). For each level has been formed 20 samples in order to determinate the value of the shear strength of bonded joint. The results were processed using the Student's t -test. This research showed that with increasing the temperature and pressing time increases the shear strength of the bonded joint, but non-linear. [ABSTRACT FROM AUTHOR]

The work presented in this paper reports on the water sorption properties of thermally modified wood, densified wood and wood modified using a combination of the two methods. The paper presents new findings concerning the sorption isotherms and sorption kinetics behaviour. The sorption kinetics is analysed in terms of the parallel exponential kinetics (PEK) model which has recently been introduced to the wood science community as a better alternative to the often used Fickian models, at least where cell wall sorption behaviour is considered. The PEK model comprises two exponential sorption kinetic terms which are termed fast and slow sorption processes. The PEK model is then interpreted by using a relaxation-limited kinetics model consisting of two series-coupled Kelvin-Voigt elements. [ABSTRACT FROM AUTHOR]

A study was carried out to investigate the effect of thermal treatment on biological resistance of Populus tremuloides wood against four decay fungi, including T. versicolor, P. placenta, G. trabeum and C. puteana. The weight loss data showed that degradation of untreated wood by the white rot fungus T. versicolor resulted in higher weight loss (571%) compared to those by brown rot fungi G. trabeum (21•9%), P. placenta (36•7%) and C. puteana (7 1%). When this species was heat treated at 220°C, the weight loss was reduced to <10%. Increasing temperature and the holding time appeared to affect the resistance against I versicolor, P. placenta and G. trabeum attacks, but the effect on the resistance against C. puteana was not significant. The humidity during thermal modification affected the degradation of wood against I versicolor attack, but it did not have a significant effect on the other fungi. [ABSTRACT FROM AUTHOR]

The moisture content of wood is known to have a significant influence on the wood's mechanical properties. Using wood as an energy absorber in impact limiters of packages for the transport of radioactive material, it is of particular importance to ensure the moisture content and thus relevant mechanical properties to be in specified limits. The paper surveys the influence of wood moisture content on the mechanical properties of wood. Different measuring methods are discussed with respect to in situ applicability, accuracy and effort. The results of an experimental analysis of the accuracy of hand held moisture metres using the electrical resistance method are discussed. Conclusions are drawn regarding the measurement of moisture content of wood upon delivery as well as of complete impact limiter assemblies. Requirements for quality surveillance during manufacturing of wood filled impact limiters are derived and it is exemplified how to meet them. Construction, manufacturing and inspection of impact limiter encapsulation with regard to leak tightness are addressed. [ABSTRACT FROM AUTHOR]

In this study, the qualities of dimensional change and adhesion resistance of moulded concave plywood material after being exposed to water vapour have been investigated. To this end, for the production of moulded concave plywood material, Oriental Beech (Fagus orientalis) was used as the wood material; and Urea formaldehyde was used as the adhesive. The moulded plywoods were exposed to water vapour for 2, 6, 12, 24, 48 and 96 according to TS 3639 standards and their dimensional stabilisations according to TS 318 standards and adhesion resistances according to BS EN 205 standards were determined. As a result; average exact dry density has been established as 0,708g/cm³ and air dry density has been established as 0,814g/cm³. The dimensional increases are found to be % 1,03 in wideness, % 8,08 in thickness, % 5,08 in arc openness, % 3,21 in arc and environment longitude. In the adherence resistance, the highest value is stated in the control group paralel to the fibres with 4.07 N/mm²; the lowest one is stated as 1.19 N/mm² in the examples which are vertical to the fibres and were exposed to hot water vapour for 96 hours. According to this: moulded concave plywood can be used in the areas prone to be exposed to water vapour for 48 hours or less. [ABSTRACT FROM AUTHOR]

Variations of relative humidity and temperature result in moisture and temperature gradients in wood, which induce stress perpendicular to grain and may even cause cracking of the wood. To address the problem, a sequentially coupled three-dimensional (3D) finite element procedure was developed for investigation of hygrothermal stress in glulam beams, in which moisture and heat transfer were taken into consideration, and the hygrothermal deformation, creep, and mechanosorption were also included. The moisture content, temperature, and stress distributions in glulam beams were modelled successfully. The study provides insight into the mechanism of hygrothermal stress in glulam and also provides useful reference to the design of glulam structures and the design of lamina stacking sequence in production of glulam. [ABSTRACT FROM AUTHOR]

The article investigates the effect of the digester kappa number on the bleachability of softwood extended modified continuous cooking kraft pulp. In laboratory bleaching, the physical properties of the bleached pulp models were predicted based on the digester kappa number and the CIO2; charges in the D stages. The most cost-effective targets below 88 percent International Organization for Standardization (ISO) is required for the final brightness. However, for a targeted brightness of 90 percent ISO, kappa 21 acts the highest degree for cost-effective delignification.

An introduction to the journal is presented which introduces several articles within the issue on topics including insight on the mode of action of brown rot decay of modified wood based on DNA and gene expression studies, steps in developing thermally modified timber, and modification of wood with biopolyesters.

An introduction to the journal is presented which features several articles from the Seventh European Conference on Wood Modification on topics including thermo-hydromechanical wood behaviour and processing and performance of bio-based building materials.