COST Action E37: Sustainability Through New Technologies For Enhanced Wood Durability STATE OF THE ART IN ROMANIA

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1 COST E 37 Ljubljiana 4-6 June 2004 NATIONAL INSTITUTE OF WOOD BUCHAREST STATE OF THE ART IN ROMANIA by Dr. eng. Octavia Zeleniuc National Institute of Wood Prof. dr. Maria Cristina Timar - University Transilvania Brasov Dr. biologist Livia Bucsa - University Lucian Blaga Sibiu ABSTRACT This document is structured to offer contact information for participants and an introduction to their principal interests and research activities within the scope of the COST Action E 37. There are three Institutions involved in research and activities in the field of wood preservation participating at this COST Action. The second section within this report gives some details on specific activities related to the three working groups within CA INTRODUCTION One important advantage of wood compared to other materials is its renewability within a biologic ecosystem. Because wood, as a biological resource, owns a high variability in its inherent material properties, more maintenance and special treatments are necessary to guarantee a long-lasting service. The use of preservatives treatments is a possible alternative to substitution of durable timber or non timber products but the public concern for the environment increase pressure on industry to focus on pollution reduction. In this context it is necessary to pay attention on the development of a newer durability enhancing products and technologies. Extensive research, especially in the last 20 years, has demonstrated that chemical modification of wood elements enhances some of wood properties, including the resistance at biodeteriogens. 2. WOOD COMPOSITES The solid wood industry is changing. Traditionally, much of the raw material used was large diameter, old-growth timber. This type of resource afforded much clear, tight-grained wood that was well suited for production of high-strength structural lumber and panels. That resource has largely disappeared and is increasingly unavailable from public forests. In this case the industry has to turn to second-growth timber to ensure the necessary quantity and quality. However, this material needs different processing methods for making commodities that perform as well as those made from old-growth timber. 1

2 In this way the production of wood composites increased and diversified. We can define as composites: plywood, hardboard, particleboard, medium density fibreboard (MDF), oriented strandboard (OSB), laminated veneer lumber (LVL), which are often labelled as engineered because their mechanical properties can be controlled during manufacture and are not solely determined by nature. Despite their large diversity, these composites still need to improve their durability and stability in time. The problem of improving natural durability and service life in outdoors utilisation can be approached starting with the improvement of dimensional stability of wood. Negative behaviour related to these properties can be improved by:! Chemical modification of wood, meaning the chemical reactions between OHgroups of wood and different chemical reagents, leading to formation of steady covalent bonds.! Wood impregnation with resins or reactive monomers or oligomers that will harden within the wood structure, both in the cell lumen and the cell wall, blocking the water access towards active centres of swelling and shrinkage of wood.! Physical insulation of wood surface by finishing and treatment with hydrophobic products. The researches made in order to improve the wood composites performance competence, for biological and physical durability are referring to:! Estimation of inorganic additives effects on some physical and mechanical properties of lingo-cellulose composites (density, water absorption, swelling, static bending strength.! Development of a new composite board with flat surfaces, low density, self supporting, designed especially for wood buildings. The board is made from small particle of lingo-cellulose materials bonded with synthetic resin binders or mineral binders (cement, gips) with or without adding filling materials, which can be synthetic or mineral (slag, ash); the board has pierced perforations.! Development and testing of new composites based on wood and synthetic polymers obtained by solid wood impregnation with monomers afterwards in situ polymerised using gamma radiation.! Development a novel type of wood-fibre plastic composites in that the partial melting of the chemically modified wood is the matrix and the remaining unmelted wood functions as a reinforced material. Plastic like composites were obtained from the compression moulding of the thermoplasticised Aspen sawdust.! Impact damage in composite laminates (damage named BVID Barely Visible Impact Damage ). Numerical solution.! Study concerning the utilization of polyamides in obtaining new composites.! Improvement of decay resistance of Aspen by esterification with maleic anhydride (MA) and subsequent oligoesterification with ma and glycidyl methacrylate (GMA) or allyl glycidyl ether (AGE). Tests were made on veneer and solid wood.! Fitotoxicity tests as a possible method of evaluating the ecological impact of different wood treatments (chemicals)! Ecological wood preservation using waterborne polymers modified with fungicide vegetal derivatives 2

3 ! Dimensional stabilization of wood by chemical modification (maleic anhydride treatment, acetylation)! Properties of modified wood and chemically modified wood composites. Despite the great number of studies concerning new composites there is no methodology available for industrial applications. It is essential that correct test procedures to be used, knowing that only after product testing the new material can gain access onto market. The traditional treatment technologies are still used in a large extend and we must not forget that they are the basic procedures for wood conservation and restoration of historical monuments and art objects. Cultural Heritage represent a testimony of human history, it is a document and it is our duty to keep his value and integrity during time. In this case also it is important to develop new non-biocidal technologies for sterilization and conservation historical monuments and art objects and analysing the physical and mechanical wood properties in order to develop a strategy for restoration and maintaining of Cultural Heritage Infrastructure. This will lead to the preservation and salvaging of cultural heritage components with the further development of a standard procedure for damage control and monitoring techniques. 3. CONCLUSIONS The scope of Cost Action E37 is of considerable relevance and interest in Romania taking account that preservation is oriented in the following directions: lumber antisapstain, treatment of wood used in buildings, conservation and restoration of historical monuments in the view of improving their durability and maintain their integrity. It is important to have information about the interaction between old and new conservation materials and methods on structural or on surface interventions and to develop methods to control and monitor the wood biodegradation. The Romanian participation to the COST E 37 is of considerable importance for the following themes: WG1 - Principles! Newer environmentally more sensitive heavy metal free wood preservatives. WG2 - Performance! Methods of physical as well biological laboratory and field tests.! Promotion of non-biocidal methods.! Evaluation of different traditional treatment technologies and non-biocidal measures with respect to the durability requirements for different commodities.! Quality characterisation and uniform performance classification of modified wood products! Coating systems for modified wood WG3 Properties! Reduction of hazardous waste and pollution! Direct and indirect release of substances from treating processes to asses the possible environmental impact! European regulation and legislation and approval schemes 3

4 4. SELECTED REFERENCES 1. Bucsa, L. Macromycetes which degrade the wood in construction. PhD thesis Univ. Al. Ioan Cuza, Iasi, Bucsa, L., Bucsa,C. Insecticide and fungicide treatments and specific compatibility issues of timber within construction. 11 th bienal International Conference on Built Heritage Conservation, Tusnad, Romania,,p , Dogaru, F., Terbes, N., Popa, S. Concerning BVID type damage of laminates plates due to low velocity impact. Numerical simulation. Proceedings of the National Conference 4. Milos, I., Enescu, L. Effects of some inorganic additives on the properties of lingocellulosic composites. Proceedings of the International Conference-Wood Science and engineering in the third millennium p , Brasov, November Timar, M.C. (1998) Chemically modified wood for thermally formed composites. PhD thesis, Brunel University, UK. 6. Timar, M.C., Zamfira, S., Mihai, M.D. (2001) Assessing thermoplastic properties of chemically modified wood composites by dielectric analysis. Proceedings of the International Conference BRAMAT Braşov, pp Timar, M.C. chemical modification of wood a new ecological concept of wood preservation. Proceedings of the International Conference-Wood Science and engineering in the third millennium p , Brasov, November Timar, M.C., 2003: Assesing the thermoplastic properties of chemically modified wood composites by a simple thermomehanical analysis method. Proceedings of the International Conference BRAMAT 2003, Braşov, martie 2003, pg. 9. Timar, M.C., 2003: Monitoring wood weathering phenomenon by colour measurements and optical microscopy, Proceedings of the International Conference BRAMAT 2003, Braşov, martie Beldeanu, E., Timar, M.C., Mihai, M.D., 2002: Influence of surface resin treatment of wood on dimensional stability, Proceedings of ICWSE 2002, ISBN , pg Voina, S. Ligno-cellulosic perforated particleboard. Proceedings of the International Conference-Wood Science and engineering in the third millennium p , Brasov, November Zeleniuc, O. Bucsa, L. Elaboration of products and methods for the preservation and restoration of wood used in cultural-historical monuments. Research contract 5B03/2003 INL Bucharest,

5 5. PARTICIPANTS AND RESEARCH ACTIVITIES National Institute of Wood, Bucharest Contact persons: Dr. eng. Octavia Zeleniuc Chemist Mariana Pruna Research themes:! Traditional wood preservatives! Study of efficacy of wood preservatives (National and European standard)! Surface stabilization of wood products! Performance of wood preservatives in ground contact and above ground -Field tests! Sapstain and mould prevention! Chemical modification! Non-biocidal treatments! New products for conservation and restoration of wood! Biological decay of timber from historical monuments, open air museums. Control and monitor. University Transilvania Brasov Contact persons : Prof. Dr. Maria Cristina Timar timar@artimar.ro Research themes:! Chemically modified wood and products testing! Thermoplasticizasion of wood flour and solid wood! Surface treatment and dimensional stabilization! Novel products. Ecological chemicals for wood modification.! Performance of modified wood.! Properties of modified wood and chemically modified wood composites.! Anhydride modification University Lucian Blaga Sibiu Contact persons : Dr. biologist Livia Bucsa Dr. biologist Corneliu Bucsa Rest. Valeriu Olaru istorie@ulbsibiu.ro 5

6 Research themes:! Biological decay of timber from historical monuments, open air museums.! Diagnosis of damage produced by fungi in buildings! Testing the compatibility of some protective treatment of timber with artefacts.! The study and monitoring of microclimate for predicting risk of biodeterioration.! Monitoring the wood protecting measures in open air museums and restored monuments.! Traditional technics of timber! Development of building techniques to diminish the risk of biological attack of timber structure ANNEXES Annex 1 lists the Organisations who responded to the request for information, together with details about their contact persons and co-ordinates. Annex 1 ORGANISATIONS ACTIVE IN ROMANIA IN THE COST E 22 FIELD OF WORK AND THEIR PRINCIPLE CONTACTS National Institute of Wood Wood Preservation Laboratory Dr. Octavia Zeleniuc 7, Sos. F-ca de Glucoza street PO Box 30, code Bucharest Tel: Fax: office@inl.ro Web: University Transilvania Brasov Faculty of Wood Industry Prof. Dr. Maria Cristina Timar 29 Eroilor street, Brasov Tel/fax : Tel: cristinatimar@unitbv.ro timar@artimar.ro University Lucian Blaga Sibiu Faculty of History and Heritage Dr. biologist Livia Bucsa 10 Victoriei street, Sibiu istorie@ulbsibiu.ro 6