Your search resulted in 48 documents. Displaying 25 entries per page.
Management of the wood and additives wastes in the wood processing industries: Problematics and technical answers review
1996 - IRG/WP 96-50073
Management pathways for pure wood subproducts are well known and used; but as soon as additives like preservatives, glues, varnishes or coatings are present within the wood wastes, their disposal or valorization becomes more tricky. The different kinds of mixed wood wastes of the wood processing industries, from the sawmill to the furniture manufacture, are identified herewith and their diversity is examined. These wastes can be classified according to their danger characteristics, taking into account the type of additives, their concentration, their availability for the environment, the physical state of the waste. Different disposal pathways are then considered. Combustion, with the possibility of energetic valorization seems the best answer for a major part of these wastes. But this is only possible if good combustion conditions are defined, so that no harmful products are emitted. Moreover, these conditions must be affordable on the technical and economical point of view. Then, some wastes cannot be burned in such a simple way, and need a larger approach, which is presented in this document.
S Mouras, G Labat, G Deroubaix
Possible regulatory status of treated wood waste and implications
1998 - IRG/WP 98-50101-07
In relation to the European Community or the French regulations, treated wood waste can get two different regulatory status: <<recycled product or fuel>> or <<waste>>. Then, into the waste status, two categories are possible for these residues: <<domestic waste and assimilated>> or <<hazardous waste>>. These different status and categories are important for the environmental issue of treated wood waste management. But they also can have strong economical implications, linked to the waste management cost on one hand and on the materials image on the other hand. On the basis of the EC regulations, up to now, no treated wood waste is namely quoted as <<hazardous waste>>. However, through the classification criteria defined by different EC directives, creosote or heavy metals treated wood waste could be to considered that way. The technical arguments for such a classification and the practical implications are discussed.
The biological natural durability of timber in ground contact
1994 - IRG/WP 94-20051
The BRE ground contact field trials for the determination of the biological natural durability of different timber species have recently been reviewed. The data obtained from these trials have been used to appraise the different ways in which natural durability may be expressed. It is concluded that the use of the mean as a method of assigning the timber to one of five durability classes may be acceptable where general recommendations are required, for instance in association with the use of wood preservatives to enhance durability, but that the median provides a better indication in this context. Where a specifier requires more detailed information on timber performance, the mean (or median) is inappropriate and a system of percentile values would be more informative.
G A Smith, R J Orsler
The present classification of wood degradation factors
1994 - IRG/WP 94-10071
The revised version of classification of wood degradation factors is presented after discussion and remarks sended by IRG-Members. The classification contains the biotic and abiotic factors in two aspects: etiological and symptomatical.
Practical consideration in developing an international hazard class standard: The hazards and risks
1996 - IRG/WP 96-20091
This paper discusses the concept of hazards and risks in relation to the way in which the hazard class philosophy may be used for international standardization. The difference between hazard and risk is considered as a basis for a simple classification of biological hazards for timber in use based upon its service environment. The paper proposes that the moderating influences within a service environment may be regarded as risks and used to classify the severity of hazard. These risks depend principally upon geographical location (climate) and design features controlled by the specifier. It is concluded that a pragmatic and simple approach could provide the best opportunity for an international agreement.
R J Orsler
The present classification of wood degradation factors
1993 - IRG/WP 93-10031
Contemporary classification of biotic and abiotic wood degradation factors is presented in two aspects: etiological and simptomatical one.
A method of predicting the average life of field tests on preservative-treated stakes
1977 - IRG/WP 297
The paper presents an analysis of the results of completed field stake tests on untreated and preserved timber, and develops a method of predicting the average life of incomplete stake tests on wood preservatives from the failures that have occurred so far.
D F Purslow
Results of field tests on the natural durability of timber (1932-1975)
1976 - IRG/WP 3105
This paper describes a continuing field stake trial to determine the natural resistance of different species of timber to decay. Data are presented for about 180 timbers, covering over 6000 stakes, and the results are discussed in terms of a natural durability classification.
D W Purslow
Japanese Classification of Wooden Building Members for ISO Use Classes according to the Building Code in Japan.
2006 - IRG/WP 06-20337
Because of the international approve of use class system for the biological degradation of wood by ISO/DIS 21887 and ISO/DIS 21892, Japanese committee of ISO/TC165/SC1 asked to the JWPA for classify the wooden commodities by use class of these draft ISO. The JWPA was prepared a draft use class model in Japan. Japanese building code systems are described and Japanese draft use class system is also described.
Survey of conditioning treatment practices in India
1978 - IRG/WP 3127
India has 75.3 million hectares (ie about 24% of total land area) under forests out of which the area of productive forests, from which industrial wood is available, is about 60 million ha. The Task Force on Forest Resources Survey has tentatively estimated that the total growing stock in Indian Forests is 24,000 million cubic metres (m³). The total recorded production of wood in the country is roughly estimated as 25 million m³ annually of which approximately 10 million m³ is demanded by various industries and the remaining is used as fuel. India, with developing economy needs very large resources of timbers for diverse purposes. There is already shortage of timber in the country for various wood based industries and it is expected this will progressively increase with the rapid pace of industrialisation. However, suitable measures are being taken to bridge the gap between demand and supply. The entire 10 m³ of industrial wood requires some sort of protection against wood-destroying agencies. Timber awaiting conversion during storage needs prophylactic treatment while for use as poles, fence posts, sleepers, building material, in cooling towers, boats, ships, in mines, in sea-water, etc., timber should be adequately treated with suitable wood preservatives to obtain satisfactory service life. Both heart and sapwood of non-durable species and only sapwood of durable species need protection against wood-destroying agencies. Wood Preservation on scientific and modern lines was introduced in India by Sir Ralph Pearson of the Indian Forest Service in the year 1908. In India, the first wood preservation plant was established at Bally in Howrah in 1854. Of the total timber extracted in India, only a very small proportion, estimated at about 5% is treated. This amounts to 0.45-0.50 million m³ of wood per annum. The total annual capacity of 140 preservation units, existing in the country at present, is estimated at 0.43 million m³ on single shift basis. IS: 401-1967 (Indian Standard - Code of Practice for Preservation of Timber) covers types of preservatives, their brief descriptions, methods of treatment, and the type and choice of treatment for different species of timber for a number of uses. This standard includes only such preservatives and methods of treatment which have given satisfactory results under Indian condition of service. According to this standard, whatever process of treatment is adopted, timber for treatment should be sound and should be dried to an appropriate moisture content (generally not more than 15% for open tank and 25% for pressure processes). All the wood working etc should be done prior to treatment. In case of timbers, specially some conifers having non-durable heartwood which is refractory to treatment, when treating thick members like railway sleepers, beams, piles, etc, incision of all the surfaces, other than the ends, to a depth of 12-20 mm is necessary.
M C Tewari
Natural durability of eight tropical hardwoods species from Africa
2005 - IRG/WP 05-10563
Current forest inventory results reveal that there are more than 700 hundred-hardwood species in tropical forests, of which less than 10 percent are harvested and used for commercial purposes. The increased use of lesser-known species can decrease the pressure on current commercial species, increase the value of the forest and lead to better management practices. However basic information on physical, mechanical, treatability, and durability properties of these lesser-known species are necessary before they can be advertised as suitable replacements for current species. This project investigates the natural durability to brown rot and white rot fungi of eight tropical commercial and secondary hardwood species: Ayous (Triplochiton scleroxylon), Acajou (Khaya ivorensis), Frake (Terminalia superba), African padauk (Pterocapus soyauxii), Amouk (Microberllinia brazzavilensis), Ilomba (Pycnanthus angolensis), Iroko (Chlorophora excelsa) and Parassolier (Mussanga cecropioides). The soil block test procedure was conducted according to ASTM D2017-81 standard. A classification scheme based on above ground and ground contact end uses was developed. In addition the eight species were ranked using a Wilcoxon matched pair statistical test on SAS. Seven of the eight species investigated were susceptible to white rot fungi, while Iroko and African padauk were the only species highly resistant to brown rot fungi. Based on the end use classification scheme, Amouk, Frake, African mahogany, African padauk and Iroko all showed potential for above ground applications, while only African padauk and Iroko showed potential for ground contact applications.
P Nzokou, K Wehner, D P Kamdem
Natural Durability Classification Systems Used Around the World
2009 - IRG/WP 09-10694
Around the world natural durability is classified in different ways. The nature and rigor of the tests used to measure durability, the method of classification based on these data, and use of these classifications to specify end uses or predict service life all vary. This can lead to confusion among people not familiar with the various systems used. This review describes the methods used to classify naturally durable wood around the world.
Chapter 6 - Preservatives of bamboo
2007 - IRG/WP 07-10635-06
Almost all currently available oil-borne, water-borne and compound types of preservatives suitable for the preservation of bamboo or wood have been described along with their classifications, applications, formulations, merits and demerits, history of invention or discovery and development. The preservatives suitable for wood are also considered suitable for bamboo.
A K Lahiry
Development of an Australasian protocol for assessment of wood preservatives
1994 - IRG/WP 94-20043
The Australasian Wood Preservation Committee (AWPC) is currently developing a suite of assessment procedures (protocols) for the biocidal efficacy of wood preservatives for approval in Australasia (Australia, New Zealand, Papua New Guinea, Fiji). Protocols are being prepared for the six hazard levels recognised in the relevant standards of member countries and represent the minimum procedures required to provide biocidal efficacy data which may be needed to obtain preservative approval and registration by the appropriate regulatory authorities. The protocols cover a combination of laboratory and/or field testing. This document presents a brief outline of the proposed format of the protocols.
W D Gardner, H Greaves, M E Hedley, K J McCarthy, J Norton
CCA treatability of 100 timbers of Bangladesh
1996 - IRG/WP 96-40069
CCA treatabilities of 100 timber species grown in Bangladesh have been compared with the treatability of Pole pine (Pinus caribaea) grown in Bangladesh which revealed new five treatability grades. Sapwood of 48% species and heartwood of 9% species was found to be treatable with CCA under grade (++++) having 100% penetration. Like softwood where CCA penetrates completely in cell lumens and cell walls effectively, the timbers under grade (++++) are usable for long term best utilization in contact with soil and water. The service life of timbers under treatability grade (+++), (++), (+) and (-) having 75%, 50%, 25%, and 00% penetration respectively would be proportionately lower if used in contact with soil and water. The heartwood of 61% timbers was found to be refractory to CCA treatment even at higher impregnation pressure (12.5-18 kg/cm²), higher initial vacuum (500-830 mm Hg) and pre-treatment moisture content of 10%. Revealed that the highest treatability was limited within whitish wood and the highest impermeability was limited within deep couloured wood (e.g. reddish, blackish, brownish etc.).
A K Lahiry
The natural durability story
1997 - IRG/WP 97-20119
Wood species with superior natural durability were in use since the beginning of timber utilisation. Their importance decreased with increasing industrial timber impregnation. In recent time, however, they gained worldwide new interest due to environmental problems involved with treated timber. In Europe a special Standard (EN 350) has been published and a multinational research project on testing procedures is in progress. This paper refers to former investigations as well as to actual research work and tries to summarize the problems of investigation and classification of the phenomenon known as natural durability. By this the urgent demand on international co-operation regarding sampling, test procedure and classification systems is demonstrated.
H Willeitner, R-D Peek
Statistical evaluation of 'micro-bending' samples for classification of wood attacking fungi
1992 - IRG/WP 92-1544
Micro-specimens from both hardwood and softwood were exposed to selected species of field isolated fungi. The strength reduction and weight loss caused by these fungi were determined. A statistical procedure was then developed to classify the fungi into brown-, white-rot, or non-decay fungal categories based on these data. The procedure reveals the extent of hazard a fungus poses to wood members. Using established base criteria as described herein, the procedure can be used to classify unknown field-isolated fungi to a pre-specified degree of certainty. Although this approach to fungal classification is not novel, it has not been used previously for decay classification. Implementation of similar classification procedures employing additional parameters would help to refine the approach allowing laboratories other than those specializing in fungal taxonomy to conduct accurate decay analyses on field samples.
B Goodell, Jing Liu, A Homola, J Jellison, J Shottafer
Is laboratory testing of decay resistance questionable as a single criterion for natural durability?
1996 - IRG/WP 96-20096
In a laboratory test set up over 20 hardwood species were evaluated according to the European Standard EN 350-1 including Basidiomycete and soft rot testing. Half of the species used were of a known natural durability. The Basidiomycete testing was carried out using Coriolus versicolor, Gloeophyllum trabeum and Coniophora puteana in a malt agar test similar to EN 113. From this test it was not possible to rank the wood species according to known natural durability, only a distinct differentiation between species belonging to the group of durability classes 1 to 3 and the ones of durability classes 4 and 5 was noted. Since most wood species with little information on durability are so-called lesser known species belonging to the tropical hardwoods, it seems that only limited additional information is gained from brown rot tests supplementary to white rot tests. Both types of laboratory soft rot tests according to ENV 807 (vermiculite and soil) are able only to identify significantly the durability classes 1 to 4 from class 5, although somewhat better indications are obtained from the soil test. It is evident that other types of fungal attack like blue-stain in service, being an important parameter for window joinery, is not correlated at all with natural durability data obtained from soil testing. It is concluded from this research that durability testing would be better hazard class oriented in order to identify functionality of the end products derived.
J Van Acker, M Stevens, T Van Cauwenberghe, T Seynaeve
Laboratory tests on the natural durability of timber methods and problems
1984 - IRG/WP 2217
In literature a large variety of test methods is mentioned to examine the natural resistance of timber against fungal attack. This concerns the kind of sampling as well as the test procedure, the test fungi, the duration of test, and the classification of the resistance according to the test results. These variations, however, are of great influence on the test result. Long term exposure will lead to a further differentiation of timber species to be generally known as "resistant".
Revised South African standards for wood preservation: Protocols for approval of wood preservatives
1995 - IRG/WP 95-20072
In 1994 the South African timber treatment industry completed its revision of the South African Bureau of Standards (SABS) Code of Practice for the preservative treatment of timber. These revisions were undertaken in parallel with changes to the SABS specifications for preservative treated timber. As a result of shortcomings in the previous wood preservative classification system which was based on exposure conditions for treated timber, the hazard classification for wood preservatives in force in South Africa has changed. The paper details the newly adopted classification system and its role within the current legislation requirements. Specific reference is made to the performance and toxicological data required for registration of a wood preservative in South Africa. Requirements in terms of an industry-approved South African Bureau of Standards (SABS) standard "product" specification and compliance with the SABS standard "treatment" specification are also discussed in more detail. Existing test requirements, protocols and procedures for approval of new wood preservatives are summarised. In addition, the paper identifies possible changes that could lead to more appropriate testing and acceptance procedures which reflect the real preservative needs of the various hazard classes.
D Conradie, P Turner, W E Conradie, A D Currie, I S J Burger
Possibility and problems of characterizing treated wood after service with regard to disposal
1993 - IRG/WP 93-50006
For the disposal of wood waste under ecological conditions, information about its hazardous potential and the logistic aspects for its handling is needed. The main criterion to evaluate the hazardous potential besides the determination of the type and quantity of active ingredients in the wood will be the degree of mixture with different treated or untreated timber. Assortments can be homogeneous (e.g. creosoted ties), partial homogeneous (e.g. poles with various chromium containing types) and mixed (e.g. wood from demolition of buildings). To improve the possibilites of re-using, recycling or disposal, a comprehensive survey on the structure of ownership, the kind of accumulation and the quantities of waste wood will provide with basical information. The evaluation of these logistical aspects can help for example to avoid mixed assortments, to decide whether separation as well as concentration may be useful and possible and to choose a suitable disposal method. As conclusions unsolved problems are identified.
A Voss, H Willeitner
Termite resistance classification of some tropical and temperate species based on the laboratory choice test results against formosan termite, Coptotermes formosanu
2004 - IRG/WP 04-20291
The results of classification of termite durability were varied. We carried out laboratory evaluation of the classification of termite durability on various species by the choice test against formosan termite, Coptotermes formosanus. We classified five grades (very sensitive to very resistant). According to our results, azobe, ipe, keruing, intsia, kapur, yellow meranti, jarraah, malas, cypress pine, alaska-cedar, hinoki and hiba, were indicated rather high termite resistance and four species, siberian red pine, teak, terminalia and gmelina, were shown very variable termite durability.
Differentiation of Scots pine heartwood and sapwood by near infrared spectroscopy
2003 - IRG/WP 03-10459
In Scandinavia Scots pine heartwood has, in recent years, gained popularity as material for external structures exposed to moderate risk of decay. As non-durable sapwood surrounds the heartwood in pine trunks it is of crucial importance to separate this wood from the heartwood during log processing into heartwood products. Heartwood and sapwood can be differentiated by visual evaluation of colour differences, since the heartwood become darker when exposed to sunlight for some time. However, in many cases it can be very difficult to identify heartwood and sapwood visually, for example on wood surfaces not exposed to sunlight or on surfaces only containing one of either heartwood or sapwood. This paper presents a method for non-destructive classification of Scots pine sapwood and heartwood based on near infrared (NIR)-spectroscopy and multivariate data analyses.
P O Flæte, E Ystrøm Haartveit
International standards - can we make them simple? Stage 2: Reflection arising from the discussion at IRG 27
1996 - IRG/WP 96-20103
For the purpose of the ISO FAST TRACK project on preventive wood protection and durability, one shall refer to the 3 following stages: Hazards: (for wood in service), a review of biological agencies defining the scope; Exposure: a review of local, geographical parameters influencing the virulence of biological agencies towards wood in service (i.e climate indexes); Risks: as a combination of hazards and exposure. Risks vary considerably with exposure for an occurring biological agency (hazard) and can only be managed locally on the basis of local assessment. Local levels of prescription, associated to service life, need be listed to harmonize prescriber procedures. They may be recorded as informative annexes on the basis of local declarations. How can we make them simple ? A proposal: 1 standard 4 chapters informative annexes: Part 1: Wood biological hazards Inventory Part 2: Wood protection parameters Inventory Part 3: Wood preservative specifications Part 4: Treated wood specifications Insertion of TC 38 standards: Part 1, annex 1 = EN 335 Part 2, annex 1 = EN 350 + EN 460 Part 3 = EN 599 Part 4 = EN 351
Information from the COIPM wood group. (With Appendix: Préserver les matériaux en milieu marin sauvegarder l'environment marin telles sont la vocation et la mission du C.O.I.P.M.)
1989 - IRG/WP 4156
During the last COIPM Meeting, up to date information on cooperative work to test the resistance of plastic wrapping for pilings were submitted and discussed. In 1986 untreated wood samples wrapped with shrinkable polyolefin sleeves were submerged in 9 stations, situated in temperate and tropical waters. After 1 or 2 years of immersion the samples showed no sign of penetration by marine borers and the surface of wraps was intact. The samples showed moderate to extensive fouling on their surface The control samples in Mediterranean Sea were destroyed within a year. The degree of attack by marine borers and the characteristics of the sites (temperature, salinity, pH) are reported in Tab.1. A study on the biodegradation of waterlogged archeological woods from a 2,500 year old shipwrech was presented. The shipwrech, probably a Greek merchant boat, was detected many years ago near the Isola del Giglio in Tyrrhenian Sea and partly brouht up. The wood samples recovered belong to the ship-planking and to some tools and instrumets, even musical instruments such as flutes. The woods show a severe marine borer attack. At the moment the wood specimens are preserved in water with a fungicide solution. The various decay patterns of the cell wall were illustrated by photos and dias. This study is carried out by Wood Institute of Florence in collaboration with the Archaeological Museum and includes the identification of wood species (three sofwoods and ten hardwoods), their biodegradation and the conservation treatments. A classification on the wood natural resistance against marine borers in Mediterranean Sea and in temperate waters was discussed. This classification was prepared by the Chairman for the Working Group 2 "Natural durability" of CEN/TC 38.