British Timber Seminar
The evening of 29th November 2017 saw the WTS host an event about the developments in British timber and subsequent products.
The audience consisted of students from nearby UCL, WTS members, and colleagues from architecture and engineering, who were welcomed by John Park - Chair of the Wood Technology Society.
Three speakers, photographed above, (from left to right) Dan Ridley-Ellis, Morwenna Spear and Martin Ansell, gave extremely enlightening and stimulating presentations.
Dr Dan Ridley-Ellis, Associate Professor at Edinburgh Napier University, started the proceedings with a presentation on "Home Grown Timber - Now and In The Future."
Dan's summary is as follows: "We are not only changing what we can do with wood – we are changing the characteristics of the wood too. Trees grow wood according to their own needs, but we influence this through forest management, tree breeding and by climate change. British forests in the future will be different – not just because we are beginning to plant a wider range of species, but also because we are changing the familiar species too. We have good reason to be optimistic about improving British timber quality, but we should also look with fresh eyes at what we currently have. The commonly heard dismissal of British timber as too fast grown, too low density, and unsuitable for construction simply isn’t an accurate reflection of reality. There are many opportunities to better use the timber we already grow. This presentation covered what we mean by wood quality, what properties are important for different applications, how we affect them through silviculture, and how confusion arises from terms like ‘rate of growth’. This presentation drew on many years of previous research projects at Edinburgh Napier University and ‘Strategic Integrated Research in Timber’ partners, including Forest Research. And, using preliminary data from ongoing research projects looked to the future – at species with potential for more diverse planting, and more resilient forests."
Dr Morwenna Spear, Research Scientist at the BioComposites Centre, Bangor University, presented the second lecture on “New products from UK timbers”.
The aim of the presentation was to review recent and ongoing progress in the timber sector, in product development within the UK. Two main fields were discussed: structural elements (CLT and glulam) and wood modification. Both technologies potentially hold benefits for UK timber species – increasing stability by lamination or by modification respectively. However both technologies also present challenges to the timber industry in the UK, such as grading of less-used species of wood; improvement in drying; and highlighting the permeability issues of many species. This is a very interesting time for the wood technologist, and for those seeking to invest in development of the emerging technologies.
The talk highlighted several current investments and expansions, and reported the status of interest in UK-based manufacturing of new wood products. The timber sector has shown steady growth, now ranking in the top ten UK manufacturing sectors, and confidence in the wood based panels sector is strong, as demonstrated in the two recent announcements of expansion at Norbord and Chirk. These greatly help the volume of home grown timber in domestic construction. In the CLT arena, the potential of the product is increasingly well recognised, and imports of CLT from the DACH region are steady. Helped by the rise of many high profile tall timber buildings, market projections indicate strong growth in CLT production within Europe. The big questions are when and who will seek to demonstrate the same growth in the UK, and will they do so using home grown timber?
The wood modification sector has also shown expansion in the UK. Demonstration projects in thermally modified timber, and the establishment of the Brimstone brand by Vastern are one example. This is particularly noted for its Grown in Britain status, and is the best example of product development from home grown timber. The other significant investment is the development of a modified wood production facility by Fibre 7 at Barry in South Wales. This resin modified timber shows great potential in exterior and interior applications, in particular relating to dimensional stability, durability, hardness. Application to domestic timbers is being considered by the company and research is underway with Bangor and Coventry Universities in this field.
Dr Martin P. Ansell, Reader in Materials in the Department of Architecture and Civil Engineering, University of Bath, completed the evening by presenting a lecture on “Wood composites – microscopic to macroscopic”.
The presentation was in three parts and began with an exploration of the composite structure of the wood cell wall. The orientation of the stiff cellulose molecules (microfibrils) arranged in spirals in the thickest S2 layer of the wood cell wall determines the elastic modulus and strength of the wood. Small microfibril angles (MFAs) result in stiffer cell walls and therefore wood with a higher MOE. The SilviScan-3 system is able to determine the density profile across a section of annual rings and can precisely determine MFAs in the earlywood and latewood of each annual ring. Results were presented for Douglas fir grown in the south west of England. In the latewood of sapwood MFAs lie in the range of 15 to zero degrees meaning that the cellulose microfibrils are close to parallel with the axis of the wood cell, whereas in the heartwood MFAs are significantly higher.
The second part of the talk was concerned with novel carbonized and mineralized wood composites. Pyrolyzed wood scaffolds may be infiltrated with molten silicon to form silicon carbide composites for use as heat sinks for solar panels and microwave transmitters. Carbonized wood has also been used as a substrate for the growth of titanium carbide crystals, retaining a porous, cellular structure which could be used for high temperature resistant exhaust gas filters, catalyst carriers, waste water treatment and structures for acoustic and heat insulation. Infiltration with molten aluminium alloy converts a carbonized wood scaffold into metal fibre reinforced composite where mechanical properties can be determined by the wood porosity.
The final section of the presentation was concerned with macroscopic hybrid wood composites including First World War fighter planes, wind turbine blades and the construction of skis. Examples of hybrid timber buildings were reviewed encompassing the superstructure of the Thames Barrage, the Savill Building in Windsor Great Park, the Richmond Olympic Oval in Vancouver and Curtain Place and the BSKYB Believe in Better Building in London. It can be concluded that wood is a composite material in its own right but may also be a scaffold for composite structures or a key element of hybrid composite buildings.