BRE's new state-of-the-art research kiln (Supplied by Kiln Services Ltd. of Essex)

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1 BEST UTILISATION: Issue 4, Winter 2002/03 News of BRE-CTTC's work on UK Timber Editors: Mr. Keith Maun Tel: Dr. Richard Thompson Tel: Introduction We are pleased to send you Issue 4 of our newsletter, which summarises our UK timber related activities in the Centre for Timber Technology and Construction at BRE. The information provided follows on from Issue 3, presenting new projects and updating the progress on others. The newsletter provides a brief insight into the projects. If you would like to learn more about any project, or would like to become more involved, please do not hesitate to contact us. Drying (EU, DTI, FC and Ind.) The EU and DTI drying research programmes are both going very well. To date five packs of UK material have been delivered to research organisations in Finland, France and The Netherlands for wood drying trials involving high temperature and novel top-loading methods. The results are very encouraging and changes are being made to subsequent schedules to further improve distortion and reduce drying times. The industrial partners have received a report on the trials undertaken to date. The Forestry Commission supported project on improving and accelerating the conventional kiln drying of UK spruce, was initially delayed by the need for BRE to install a fourth kiln that is representative of those used by the UK's major softwood mills. The new kiln complements BRE s older side fan kilns which are still representative of many UK sawmills. The installation of the new stateof-the-art kiln gives BRE the capability to dry timber at temperatures far exceeding current industry practice, with high velocity air flow, using one of Europe s most up-to-date control systems. This will enable us to assist the sawmillers to get the most out of their current kilns and to help them define the future direction of kiln drying in the UK. We are pleased to announce that the new kiln has been fully operational since the summer and the initial packs of timber (reference and experimental) have been dried successfully. The initial results from these trials were presented to the softwood drying group during a dissemination meeting at the end of November, along with results from several other projects. BRE's new state-of-the-art research kiln (Supplied by Kiln Services Ltd. of Essex) For more information on timber drying R&D please contact Keith Maun (above) or Geoff Cooper. Tel: , cooperg@bre.co.uk. UK Spruce for joinery (SE & Ind.) Following a successful feasibility study on the use of Scottish spruce for joinery, BRE has now started a new project to put these findings into practice. Falling boards and battens have been selected from BSW to meet the growth rate requirements for joinery. This material has been finger jointed and, where necessary, laminated to produce joinery blanks. These will be converted into prototype window frames by Jeldwen, the UK's largest joinery producer. The windows will then be assessed in service at BRE. The project will also evaluate the use of Scottish spruce for door core. A successful outcome to this part of the project could offer immediate opportunities for Scottish grown spruce to replace imported Scandinavian whitewood. Abbreviations: DTI - Department of Trade and Industry EU - European Union FC - Forestry Commission HIE - Highlands and Islands Enterprise Ind. - Industry SE - Scottish Enterprise UKFPA - UK Forest Products Association

2 Re-engineering "Boxed pith" battens (DTI & Ind) BRE has shown that battens containing pith are the main cause of badly twisted timber (shown below). 16 Twist (mm) requirements for C35. The stiffness of 90% of the laminated studs achieved C16 and over 50% achieved C24. This means that the stiffness and density of the studs will determine their strength class rather than the strength. There are real opportunities for value adding to falling boards. Twist (mm) Boxed Pith B tt Battens with Boxed Pith Absent Laminating of UK grown timber (DTI & Ind) Work is well underway in designing and manufacturing a series of gluelam beams up to 7m long made from UK-grown larch. These will be load tested to demonstrate the effectiveness of the design process. 2 0 The project aimed to improve the straightness of battens sawn from close to the pith. This was achieved by cutting boxed pith battens, deep sawing them and laminating them back together using green gluing. The industrial trials were carried out at John Gordon and Sons sawmill, Nairn. The distortion of the re-engineered battens produced was measured after drying to 18% moisture content then again after conditioning to 13% moisture content. This reinforced the considerable improvements that can be achieved through re-engineering battens containing pith. Testing of the sets of re-engineered battens containing pith versus reference battens showed almost no influence (good or bad) from the glue line on either the strength or the stiffness. At the request of the sawmilling partners a further industrial trial was carried out at John Gordon and Son Ltd. The aim was to evaluate the laminating of green falling boards (thin boards sawn from the outside of the logs) to produce studs and joists. The engineers at Gordon s mill designed and built a laminating press, which was used to produce all of the prototype studs and joists. There were some difficulties in drying the centre board of each laminated batten, but it is felt that this could be overcome through drying optimisation. There were also some pieces which were badly bowed due to the presence of compression wood. Commercial implementation would require the sorting of falling boards to exclude compression wood. This is being addressed in another BRE project. However, if these two issues can be overcome then the strength and stiffness results were excellent. The strength of all of the laminated studs exceeded the Laminated structural timber has been manufactured from Sitka spruce falling boards to produce generic stud / joist products, and I-beam flanges. Initial test results have been very good and will be verified using a subsequent batch of timber. Results from machine grading trials indicate that it should be possible to machine grade the laminated timber once it has been manufactured as current structural timber; though the current machine settings will need addressing. Scanning (DTI & Ind.) The aim of this project is to improve the utilisation, value and fitness for purpose of UK grown timber through the use of scanning technologies. The previous newsletter described: the state-of-the-art report, initial true log data collection, optimal simulation of the sawing pattern for a particular market and actual sawmill conversion. The next stage with the newly collected true log shape data is to simulate the conversion yield assuming the logs were measured with a 2 axis scanning system, a 1 axis method and no scanning. Comparisons will then be made between the optimal simulated conversion and the actual sawing. This will give a strong indication of the benefits of optimising the conversion using 3D true log crosssections describing the logs. In practice, the results of the comparison will be restrained by customer orders. An absolute comparison of the scanning systems will be carried out using computer models / simulations. A set of log conversions will be simulated for a range of products and the maximum volumetric yield from the true shape log data will be calculated. In preparation for the simulated conversions BRE has developed a series of computer routines to handle the data and has modified existing programmes which simulate

3 different scanning procedures. Test simulations have been carried out using real log data collected in the past by BRE s LOCAS system (which is no longer serviceable). These have indicated 2%-5% increases in volumetric yield when the sawing conversion based on 3D scanning is compared with other scanning systems. This confirms the results published in North America. A programme which re-constructs the measured log and orientates it to any sawing position, as well as calculating the position of maximum bow, has been developed. Sawing simulation runs have commenced. Compression Wood (EU, FC and Ind.) Compression wood is a type of reaction wood that can cause major problems in the wood processing industry, resulting in deterioration in both mechanical properties and distortion (bow and spring). This project, led by the Forestry Commission s Northern Research Station, aims to produce advanced decision support tools in the form of predictive models linking silvicultural practice with raw material properties and end product performance. A further set of 150 logs have been scanned by James Jones and Son Ltd on their log sort line. The logs were subsequently converted by James Jones and Son Ltd. There are a few 3D scanning systems being used by the UK sawmilling industry for log sorting and conversion. The high capital cost of equipment and a lack of data on potential increases in yield tends to inhibit more systems from being installed. Therefore BRE, based on experience with its LOCAS system, is carrying out development trials on a laboratory 3D scanner using off the shelf components. The future intention is to trial this at a sawmill. Work has commenced on scanning and analysing growth rate of battens and boards. Systems for measuring the slope of grain of logs on the log sort line are also being investigated. Scanning opportunities A new proposal has been being prepared on the subject of scanning. This will deal with the topics mentioned above in more detail, as well as measuring sawing accuracy, knots and other factors for on-line assessments. Sawing accuracy is particularly important for efficient kiln drying under weight and for presentation. But sawing accuracy becomes even more important when the wood is going to be reengineered by laminating If your organisation is interested in scanning technology and its application to the wood processing industry, and you would like to become involved, please contact Keith Maun. Tel: , maunk@bre.co.ik Contributions to the project are only required in kind. Compression wood (darker area) on UK spruce" Distortion caused by compression wood Detailed analysis and testing (including machine grading, bending tests to derive MOE/MOR, X ray imaging and conditioning to in-service moisture content) is underway at BRE on two large batches of timber from stands that were specially selected and categorised. Fieldwork has been carried out on two batches of logs, including 3D scanning, at Adam Wilson s sawmill, Troon. A principal aim of the project is to maintain an industrial focus. The project partners welcome additional industrial participation and have set up an End User/Industrial Participation Group.For information contact Keith Maun or Tim Reynolds. Tel: , maunk@bre.co.uk. Tel: , reynoldst@bre.co.uk OR visit the Compression wood project website:

4 Machine grading - a guide (FC) The draft report was completed and sent to volunteers in the sawmilling industry for their comments. The report is now in the process of final technical editing. The most appropriate dissemination route for this document is currently being considered. Grading X ray machine (FC) UK timber has been graded in France using the French X-ray grading machine and returned to BRE, and copies of the grading data have been received by BRE. The same timber has been passed through the Cook-Bolinder strength-grading machine at BRE and will now be tested to determine its strength. Cladding UK larch and Douglas fir (DTI) A range of comparative testing is under way to benchmark UK-grown Douglas fir and larch against western red cedar for cladding. The durability testing has indicated that UK-grown Douglas fir is nondurable and will require preservative treatment for use as an external cladding. Larch is moderately durable but preservative treatment should be considered. The testing to determine mechanical properties has been completed and has shown that both Douglas fir and larch have better impact resistance and hardness than imported western red cedar. The natural exposure weathering trails have been completed. The Douglas fir and larch showed slightly higher overall dimensional movement than western red cedar, and (unlike western red cedar) were prone to surface checking and resin bleeds. The visual appearance of the western red cedar was better than either the Douglas fir or larch. However, all three timbers were equally successful at forming a shield to the weather. With improved detailing the visual appearance of cladding made from the homegrown species could be improved. The project is nearing completion and the results are being placed on the project web-site. (projects@bre.co.uk/cladding) UK Spruce for cladding (FC, SE & Ind.) This project has recently started and a scoping document is being produced evaluating the opportunities and barriers to using UK spruce for cladding. This will be followed by benchmarking tests, and technical work to help facilitate the use of UK spruce as cladding. Pine Quality (HIE & Ind.) The project has been established to determine the quality of Scots pine from Scotland with the aim of accessing higher value added markets where possible. The project will provide the growers with a better understanding of the quality of the timber that can be produced from their trees. Incising of spruce (FC, SE & Ind.) Incising offers an opportunity to enhance the durability of UK spruce through improving the penetration of preservatives into the timber. This project will evaluate the opportunities for UK spruce. Oak beams from small diameter logs (DTI, Ind) The aim of this project is to improve the utilisation of a natural UK resource by utilising small diameter, low value, UK grown oak stems, to produce reengineered components of standard dimensions using a novel cutting and jointing technique. By using Green gluing technology (bonding wood whilst the timber is wet ) small diameter oak stems will be converted using a star cutting pattern (cut into four equal quarters), machined, inverted and bonded together to form a square. This process allows a much larger percentage of the main stem to be utilised, and ensures the less durable sapwood is completely enclosed in a solid heartwood envelope. Wood modification (DTI, EU, FC & SE) The work focuses on opportunities for UK timber through Wood Modifications. Based upon the findings from a comprehensive review, BRE has made arrangements for UK timbers to be modified at commercial and pilot plant facilities around Europe. Some of these processes were presented to the softwood drying group at the latest meeting at BRE. Following on from the promising prototype samples treated using the Dutch hot oil process, collaborative work has been established to take this forward. An initial meeting has been held with the Dutch partner to plan the work programme. A startup meeting with the industrial partners will be held in February.

5 Densification UK grown timber (FC, Ind) This project has just started, and will investigate the potential of an innovative process to add cellulose to timber thereby increasing its bulk mass and as a result its density, hardness and wear resistance. The process has been developed in New Zealand and has successfully been used on Radiata pine. The Forestry Commission, BRE and Indurite (the licensing company for the process), have established a project to evaluate the process on UK timber. The aim of the project is to establish how successful the process is on UK timber and demonstrate the potential for lower density timber to be treated and used in joinery, furniture, flooring and other value-added end uses currently not supplied by UK grown timbers. Initial tests are currently being carried out to determine the most appropriate formulation of the active solution for a range of UK timbers. Once this has been established full scale trails will commence. Modelling wood quality (FC & EU) This project aims to establish the growth characteristics that significantly influence machine grade stiffness and drying distortion of timbers, so that the information can be given to tree breeders and forest managers to help produce better crops. The models are very important and are an integral part of the EU Compression Wood and Mefyque projects, and future development work will use data collected in these projects. Innovative wood based composites (DTI & Ind.) Improved products are being developed that make more efficient use of the raw wood fibre and wood waste, and so improve performance and reduce production costs. The previous research at BRE was very successful, not only in the type of novel materials developed, but also in the improvements made in the properties of conventional wood-based products. Further requirements to maximise the research outcomes are to take the developed materials closer to market and to improve the tailoring for end use. For innovative composites with the greatest potential for further exploitation (e.g. long plant fibre reinforced oriented strand board, plant glass fibre hybrid composite, durable medium density board and Ecoboard), a comprehensive study (laboratory manufacture and testing to optimise candidate materials, prototype product manufacture and testing) is currently being carried out to determine their fitness for purpose, and to identify optimum parameters for manufacturing efficiency and the ultimate properties of the products. The project teams are actively seeking industry partners to take up the technologies developed, and have been in discussion with four major companies that are interested in commercialising the products developed in this project. Timber 2010 The "Timber in Construction 2010" initiative was launched at a workshop held on 12 June 2002 at BRE. The initiative aims to increase the use of timber in UK Construction. We have received very positive feedback from many of the workshop participants. Feedback from the break-out session enabled us to capture delegates thoughts and suggestions on how to take the 2010 Initiative forward. These views have now been brought together and used to determine the optimum way forward to maximise the success of Timber We have been in discussions with the various organisations and companies and, without exception, these discussions have been very positive. We have recently launched our new multi-storey timber frame design and construction guidance document (a key output from the TF2000 project), a BRE/ UK Timber Frame Association Digest on timber frame and the new Building Regulations dealing with thermal performance, and a BRE Digest on the environmental impacts of using timber in construction. The launch received authoritative support from the Office of the Deputy Prime Minister (ODPM) and from the Department of Trade and Industry (DTI). The launch was supported by Wood for Good, the UK timber Frame Association, the Forestry Commission, Wood Focus, Storaenso, UPM and Finnforest. The launch also included a state of the art timber frame manufacturing visit for the delegates. For more information contact Dr. Vahik Enjily, Director of the Centre for Timber Technology and Construction. Tel: , enjilyv@bre.co.uk

6 Innovawood European Research Database (EU) BRE is a partner in a European project which is developing a European web-based database of research relating to timber. The database will be searched using keywords and will include research summaries and contact details for European and nationally funded research projects from most EU countries. Each of the summaries will be provided in English as well as the national language of the lead organisation. The structure of the web site is in place and summaries are now being entered onto the system. It is anticipated that a working version of the web page will be available in the spring. More summaries will be added once the site is up and running. We will provide the web address in the next issue of this newsletter. BRE news New MD of Construction Division We are pleased to inform readers that Dr. Peter Bonfield, previously director of the Centre for Timber Technology and Construction (CTTC), has been promoted to Managing Director of BRE s Construction Division. Peter now has overall responsibility for nine of BRE s centres including CTTC. New Director of CTTC We are also pleased to inform readers that Dr. Vahik Enjily has been promoted Director of the Centre for Timber Technology and Construction. This extends Vahiks previous responsibilities to include all of the centres activities. Other news European Commission Funded Research The next generation of European research funding referred to as Framework 6 has now started. There are real opportunities for UK companies, especially Small and Medium Enterprises, to access new technologies and processes through this type of funding. If you have an idea that needs to be developed we would be happy to help you to access the funds and expertise to make this happen. We are also keen to hear from companies that have a general interest in new technology and opportunities through research and development. Conferences and Work shops August 24 th -29 th, th International IUFRO Wood Drying Conference Brasov, Romania. This gives an opportunity to get up-to-date information on drying advancements world wide. October 2 nd - 3 rd, 2003 Conference Drying Timber for Value Added Products, Athens, Greece. This is the final Workshop for COST E15. We hope that you find this newsletter helpful and look forward to providing you with updates in due course. BRE recruits wood modification expert Dr. Dennis Jones has joined BRE's Centre for Timber technology and construction from SHR (the Dutch Foundation for timber research). Dennis is an expert is wood modification and is the co-ordinator of the European Thematic Network for Wood Modification, which has twenty eight partners from fifteen European countries. Dennis also has expertise in wood and plant fibre based composites, and adhesion. He has a Ph.D in organic chemistry, and has worked for The Danish Technical University, The Biocomposites Centre, Bangor, and the School of Agriculture and Forest Sciences (SAFS), Bangor University.