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Preliminary laboratory bioassay to evaluate engineered Fibre-boards against subterranean termites C. acinaciformis (Isoptera: Rhinotermitidae)
2012 - IRG/WP 12-10768
In Australia, laboratory bioassays with subterranean termites typically contain groups of workers and soldiers in a substrate of moist mound material. This termite substrate may affect termite consumption, and the test materials create a favorable termite condition for the test. The main purpose of this test is to examine the effect of a melamine formaldehyde treatment of wood panels to evaluate the resistance against subterranean termites compared to untreated wood panels in the test. The orphaned termite populations were exposed to treated and untreated wood panels for over eight weeks. All the different treatments of wood panels were placed into 1 lt glass jar containers half filled with moistened mound material and five grams of foraging C. acinaciformis (~ 8% soldiers). The results were very conclusive with significant mass loss of the treated and untreated wood panels. Untreated panels and water treated panels showed high mass losses (40 – 60 %), whereas MF treated panels were barely attacked (5-7 % mass loss).
B M Ahmed (Shiday), H Militz, B Ozarska, I Ali, L Kloeser


Nondestructive Evaluation of Oriented Strand Board Exposed to Decay Fungi
2002 - IRG/WP 02-20243
Stress wave nondestructive evaluation (NDE) technologies are being used in our laboratory to evaluate the performance properties of engineered wood. These techniques have proven useful in the inspection of timber structures to locate internal voids and decayed or deteriorated areas in large timbers. But no information exists concerning NDE and important properties of wood composites exposed to decay fungi. For our pilot study on several types of wood composites, we examined the relationship between nondestructive stress wave transmission, decay rate and the bending properties of OSB exposed to the brown-rot fungus, Gloeophyllum trabeum (MAD-617). The following measurements were taken: stress wave transmission time (pulse echo test method), static bending test (ASTM D3043-95), and decay (expressed as percent weight). Stress wave measurements correlated with strength loss and with increasing rate of fungal decay. Stress wave NDE has great potential as a method for inspection of wood composite load-bearing (in-service) structures, detection of decay in laboratory tests, assessment of chemical additives to improve wood composite durability, and prediction of long term composite performance.
B Illman, V W Yang, R J Ross, W J Nelson


Ultra-structural observations on the degradation of wood surfaces during weathering
1987 - IRG/WP 2280
Radiata pine (Pinus radiata D. Don) sapwood was converted into blocks with a transverse face about 5 mm square and measuring 8 mm longitudinally. Transverse (T.S.), Radial (R.L.S.) and Tangential (T.L.S.) surfaces were prepared and specimens exposed to the weather inclined at 45° facing equatorially for periods of between 20-60 days. After 30 days exposure erosion of the middle lamella was observed followed after 40 days exposure by extensive separation of individual fibres at the interface of the middle lamella and secondary wall. Degradation of the S2 layer of the cell wall revealed corrugations orientated parallel to the fibre axis suggesting preferential removal of cell wall components. Further degradation proceeded by progressive delamination and checking of the S2 and erosion of the S3 cell wall layer. In addition to the above changes preferential degradation of the rays was observed in radial (R.L.S.) and tangential (T.L.S.) longitudinal surfaces.
P D Evans, S Thein


Mycological testing of plywood and board materials. Part 1: Review of information supplied by IRG members
1978 - IRG/WP 284
In December 1975 IRG members were asked for published information, information of current work in progress and views on mycological test methods for board materials. The object was to stimulate discussion and possibly establish a joint research effort within IRG in order to establish a meaningful test with reproducible results.
C R Coggins


Results on termite resistance of building materials against Coptotermes formosanus by choice test
1998 - IRG/WP 98-10275
Various building materials, included wood species, wooden board materials, thermal insulation materials and fire-protection materials, were tested for grading of termite resistance against Coptotermes formosanus. The dimension of most specimens were 2x2x2cm3. Ten repeats were prepared. The specimens were put between Akamatsu sapwood control specimens on a laboratory cultured mound colony of termite, Coptotermes formosanus. After 1 month of attack to termite, the specimens were removed from the mound colony and cleaned up. Then these final mass were weighed. The grading of termite resistance was initially estimated by mass loss of specimens. This grading was corrected by visual observation. Japanese 3 domestic species, cypress pine, Alaska- ceder, kapur and mahogany were indicated rather high termite resistance. In the case of Siberian red pine and Gmelina, the valued of termite resistance were shown variable. Tropical species plywood, inorganic board and radiata pine MDF, were shown rather high termite resistance. Other board materials were shown rather less termite resistance. Most of commercial soft wood plywood and OSB were very sensible against termite. Most common thermal insulation materials in Japan were estimated very sensitive against termite. In the case of fire protection materials, expanded concrete was rather good against termite but plaster board was very sensible against termite.
K Suzuki, K Hagio


Contribution to the testing of wood based board material
1982 - IRG/WP 2176
R G Lea


A summary of tests and practical experiences with the Pilodyn wood testing instrument
1980 - IRG/WP 282
This paper presents a summary of the reports, tests and practical experiences with the Pilodyn wood tester not only, however, concerning poles but also in other fields such as standing trees, sawn timber etc. The principle of the Pilodyn is a spring-loaded pin which is fired into the object and the depth to which the pin penetrates is correlated to physical and mechanical properties of the object.
H Friis-Hansen


Field testing of soil insecticides as termiticides
1986 - IRG/WP 1294
This paper reviews field methods used to evaluate soil insecticides as termiticides by the U.S. Department of Agriculture, Forest Service, Gulfport, Mississippi. Field tests are conducted on a minimum of five "nationwide sites" in the United States to determine the efficacy of chemicals in various soil types and against different termite species. Test results of selected insecticides are presented.
R H Beal


Use of the Pilodyn to assess deterioration of treated aspen waferboard after 30 months of outdoor exposure
1986 - IRG/WP 2254
Samples of preservative treated aspen waferboard exposed outdoors for 30 mo. were compared using pin penetrations of the 6 Joule Pilodyn. These results correlated well with rankings of treatment performance based on more laborious standard mechanical tests, and demonstrate the potential for use of the Pilodyn as a tool to evaluate wood composites in test exposures with minimal destruction.
E L Schmidt, M G Dietz


The effect of storage or simulated internal use on the durability of wood based panels to decay fungi
1997 - IRG/WP 97-20106
Wood based panels such as particleboard and medium density fibreboard are experiencing a steady increase in use, in areas from structural to decorative applications. Understanding the "natural" durability of these panel products against basidiomycete fungal decay is therefore of great importance. Various methods have been proposed or are under development to test the durability/susceptibility of various panel products to decay. Our research has shown that if the fungal exposure methods detailed in the current European pre-standard (DD-ENV 12038:1996) are used to test boards fresh from manufacture, the susceptibility ratings observed are significantly lowered by the buildup of inhibitory substances in the test vessels. The effects of storing the boards before testing, in order to remove this effect have been studied with repeat biological tests carried out at intervals of 6 months. Our results show that even after 6 months storage the effect is reduced but not totally removed. The time after manufacture and the storage conditions are clearly significant variables affecting the "durability" of test specimens taken from the boards and therefore the incorporation of an appropriate preconditioning stage into the test is essential so that the effect is avoided.
S F Curling, R J Murphy, J K Carey


Decay resistance of high performance biocomposites based on chemically modified fibres
1998 - IRG/WP 98-40120
Different partners within the framework of a European research project produced high performance biocomposites aiming at the utilisation of board materials as durable products both in dimensional and biological degrading circumstances. This paper summarises test data, which indicate the potential of board materials produced with modified fibre material. The chemical modifications applied cover a range of technologies, which were selected for scaling up experiments. Acetylation, as well as alternative methods like maleiation, phthalylation, succinylation, oxidation and silylation were investigated. Fibre source, density variation and the use of several types of glues were parameters of the total set-up. Basidiomycete testing was carried out using specific methodology for board materials elaborated in CEN standardisation committees.
V Rijckaert, J Van Acker, M Stevens


Degradation of the normal fibre walls of rubberwood (Hevea brasiliensis) by the tropical blue-stain fungus Botryodiplodia theobromae
1998 - IRG/WP 98-10286
Rubberwood was examined by light microscopy and transmission electron microscopy (TEM) after exposure to the common tropical sapstain fungus Botryodiplodia theobromae for four weeks to study hyphal colonisation of wood cells and to determine if this fungus also degraded lignified normal fibre cell walls in addition to the walls of non-lignified elements. Light microscopy revealed relatively large diameter hyphae to be abundantly present in parenchyma cells. The hyphae were also present in other types of wood cells, including fibres. TEM provided evidence of fibre wall degradation in the normal rubberwood in the form of lumen wall erosion (type-2 soft rot decay). These observations suggest that the ability of B. theobromae to degrade lignified wood cells walls should be viewed with concern when utilising rubberwood which has been severely sapstained, particularly after prolonged exposure to this fungus.
A A H Wong, A P Singh


Sustainability Through New Technologies for Enhanced Wood Durability. COST Action E37 – A New Action in the Forestry Domain
2004 - IRG/WP 04-40293
The main overall objective of the action is to concentrate on the contribution of wood durability on the sustainability through the development of systems for quality assurance and perfoamance of modified wood and wood products as alternatives to wood treated with traditional preservatives. By this means it seeks to improve and consequently increase the cost-effective use of sustainably produced European timber, wood-based fibre, and recycled raw materials. The action will seek to optimize methods for testing and characterizing durability performance against physical as well as biological factors. This will exploit relevant selected results from specific aspects of the preceding COST Action E22 on “Environmental optimization of wood protection” and in the EU thematic network for wood modification. It will also exploit specific achievements from COST Action E18 “High performance in wood coating”.
R-D Peek


Decay, decayed wood and the Shigometer
1980 - IRG/WP 281
A L Shigo


Durable fibre for durable MDF – testing Tricoya®
2015 - IRG/WP 15-40704
The chemical modification of wood has been a commercial reality for a decade on release of technologies for the modification of solid wood including Accoya®. A challenge and an opportunity for the modification technologies which typically impart dimensional stability, water stability and enhanced biological durability was the adaptation of the technology to wood based panels. This paper presents a summary of the development of Tricoya®, its testing and performance and examples of applications.
E Suttie, J Alexander, M Maes


Biodegradation of acetylated southern pine and aspen composition boards
1994 - IRG/WP 94-40020
This objective of this study was to investigate the influence of the acetylation treated wood fiber, Phenol-formaldehyde resin content level, two wood fiber species, three fungi species on the dimensional stability and decay resistence of high density composition boards. A standard ASTM method was used to evaluate weight loss and thickness change. The linear shrinkage and expansion of each species were also determined. All specimens were exposed to decay chambers for 16 weeks. Test results indicated that most of the main factors significantly influence the thickness and length changes and the decay resistance of the high density composition boards.
P Chow, T Harp, R Meimban, J A Youngquist, R M Powell


The evaluation of the occurrence of soft rot in creosoted wooden poles
1988 - IRG/WP 1368
The occurrence of soft rot decay in creosoted wooden poles for overhead power lines was investigated by collection of field samples, their subsequent microscopic examination and statistical analysis of the data collected. Examination of samples collected from 296 poles revealed that approximately 15% of the pole population studied (Eastern Electricity Board) showed the presence of soft rot decay. Further, it was found that of undated poles, (those emplaced before 1953,) 17% displayed soft rot attack.
A Wylde, D J Dickinson


Health and safety aspects of the use of wood preservatives in Sweden
1977 - IRG/WP 396
The Act on products Hazardous to Health and to the Environment (Swedish Code of Statutes SFS 1973:329) came into force on 1st July 1973. The Act cancelled and superseded the Poison Act, the Pesticides Act and the PCB Act from 1962, 1962 and 1971 respectively. Regulations for the implementation of the Act are contained in the Ordinance on Products Hazardous to Health and to the Environment (SFS 1973:334) and also in an Amendment of the Ordinance (SFS 1973:1050). A comprehensive summary of the Act and the Ordinance prepared in common by the Swedish Ministries of Agriculture and Foreign Affairs has been deposited in the IRG/WP Secretariat. Much of the information given below as regards the Act is derived from this booklet.
B Henningsson


Treatment of wood-based panel products with volatile borate
1990 - IRG/WP 3616
The paper presents recent developments in the use of volatile borate esters for the preservative treatment of wood based board materials. Several advances on previous reports are discussed. In laboratory studies, treatment times of approximately ten minutes at 20°C on boards at equilibrium moisture content provided full penetration and retentions of 1% wt/wt boric acid. Biological tests have been conducted on a wide variety of boards treated by the vapour boron method. In all cases a retention of 0.7% wt/wt boric acid gave complete protection from decay. These results are considered with regard to parallel studies on solid wood by colleagues at the Forest Research Institute, Rotorua. The advantages of vapour boron treatment for wood based board materials are discussed.
P Turner, R J Murphy, D J Dickinson


Worldwide in-ground stake test of acetylated composite boards
1997 - IRG/WP 97-40088
Acetylated wood composite stakes are being tested in ground contact (graveyard test) in seven fields around the world. Three types of acetylated wood composites were prepared: spruce fiberboard in Sweden, aspen fiberboard in Madison and rubber wood particle board in Indonesia. Two levels of acetylation were used, a high level of ~20% acetyl content and a low level of 10% acetyl content. Control boards of unmodified wood fiber/particle were also included. Stakes for the in-ground testing were taken from the boards and the size of each stake was 5x30x1.25 cm3. The stakes were put out in four continents: one test field in USA, one in New Zealand, two in Indonesia and three in Sweden. After three years of testing, results show that acetylation of wood provides excellent protection against fungal attack and minimizes swelling.
R M Rowell, B S Dawson, Y S Hadi, D D Nicholas, T Nilsson, D V Plackett, R Simonson, M Westin


Properties of plywood and Oriented Strand Board manufactured with an organic insecticide incorporated in the adhesive formulation
2000 - IRG/WP 00-40174
The efficacy of Fipronil as an insecticide has been established by laboratory and field experiments and commercial use against a broad range of insect pests for various crops. It can be used by either foliar or soil application. Development is underway for the non-agricultural uses of fipronil. Research is ongoing for the control of ants, cockroaches, fleas, ticks, houseflies, mosquitoes, termites and other pests. Several countries in the world have experienced extensive termites damage. The protection of structural and non-structural cellulosic products against termites may be required in the near future. With the increase uses of wood composites in wide ranging applications, protection against termites will represent one of the criteria of material selection. Fipronil was added in the formulation of adhesive during the laboratory manufacture of plywood and oriented strand board. The average MOE and MOR from of plywood was about 1.1 to 1.2 million psi and 8000 to 9100 psi, respectively. Shear strength and wood failure varies from 191.6 to 239.9 psi and 73% to 92%, respectively. Analyses of variance showed that statistically there were no significant different of all properties tested between fipronil concentration (0 - 375 ppm) at 5% level. This study indicates that fipronil has no affect on MOE and MOR under bending regime, and on the shear strength and the wood failure. After 18 months above and ground contact exposure in Gainesville, Florida, a level of 150 to 200 ppm successfully control the termite attack.
D P Kamdem, J H Hope, A Jermannaud


Formation of soft rot cavities in relation to concentric layers in wood fibre walls
1983 - IRG/WP 1185
A large number of timber species attacked by soft rot have been examined using light microscopy. The S2 layers in a large number of the timbers exhibited special structural features in the form of thin concentric layers. Several observations indicate that these layers may be characterised as "weak" zones by being more easily degradable than the surrounding wall layers. The chemical structure of the concentric layers is not known although some suggestions regarding their composition are given. It was observed that soft rot cavities regularly formed in the thin concentric layers. A hypothesis is put forward suggesting that T-branching occurs as a response to a chemical stimulus, possibly by sugars released by penetrating hyphae when they transverse the thin concentric layers.
T Nilsson, G F Daniel


Preservative effect of cellulose insulation material against some mould fungi and brown rot fungus Coniophora puteana in pine sapwood
1991 - IRG/WP 1484
The influence of mineral wool and loose-fill cellulose wool on biodeterioration of pine sapwood was studied. The test fungi were mould fungi Aspergillus versicolor, Cladosporium sphaerospermum, Penicillium sp. and Aureobasidium pullullans and brown rot fungus Coniophora puteana. Cellulose wool inhibited the growth of mould fungi on the face of wood contacted with insulation material at RH of 97 and 100%. During 6 months' incubation boron compounds added in cellulose wool diffused into the wood. No growth of brown rot fungus was detected in "treated wood". Mineral wool had no preventive effect on the growth of mould fungi and brown rot fungus Coniophora puteana.
H Viitanen


Soft rot
1978 - IRG/WP 179
Soft rot decay of treated wood is examined with special reference to hardwoods treated with CCA. Factors which adversely affect the chances of protection of hardwoods against soft rot are discussed. The ratio of the volume of the fibre cell wall to the volume of the fibre lumen is presented as a major factor influencing final preservative concentration in the fibre cell wall, the major strength contributing unit in wood. It is proposed that hardwoods are not necessarily more susceptible to soft rot than are conifers and that 0.2% Cu.wt/wt on gross wood will give control of soft rot in permeable hardwoods. Present and potential soft rot problems of treated conifers in North America are examined.
C R Levy


Effect of vapour boron treatment on mechanical properties of wood based board materials
1992 - IRG/WP 92-3727
The mechanical properties of Medium density fibre board, Chipboard and Oriented strand board were investigated after treatment to two retention levels of boric acid applied as a vapour phase system. A range of mechanical properties were investigated. The vapour boron treatment does not have any significant effect on most of the mechanical properties of the boards. The exception is a reduction in impact strength especially at the higher retention level.
R Hashim, D J Dickinson, R J Murphy, J Dinwoodie


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