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New applications of silafluofen to termite control
2001 - IRG/WP 01-30274
Silafluofen-based termiticides are widely used for soil and timber treatments in Japan, as silafluofen possesses advantageous properties of low fish toxicity and high chemical stability (to light, in soil, in alkaline environments, etc) in addition to high termiticidal activity and low mammalian toxicity. As new applications of silafluofen to termite control, we have developed another type of products in the forms of practical anti-termitic plastic sheets and anti-termitic plastic heat insulators which are free from the exposure risk of termite control operators and inhabitants to the sprayed chemical. Anti-termitic plastic sheets containing silafluofen in ethylene vinylacetate copolymer film have already been put into practical use, showing a high anti-termitic effect. Plastic heat insulators made of such materials as polystylene and polyurethane have the problem of the decrease in their insulating effect due to termite damage, although they have been widely used as building materials. To solve this problem, we prepared anti-termitic plastic heat insulators by impregnating silafluofen at concentrations of 0.1 ~ 0.3% into plastic foam. As a result of anti-termitic efficacy tests against Coptotermes formosanus Shiraki, these plastic heat insulators were found to be effective in suppressing the termite damage.
K Nakayama, Y Minamite, S Koike, Y Katsuda, K Nishimoto


Plastic-coated marine piling in Los Angeles Harbour
1984 - IRG/WP 4105
G Horeczko


Effects of heat treatment on water repellence and anti-swelling efficiency of beech wood
2002 - IRG/WP 02-40223
The heating of solid wood to higher temperatures is the simplest and the cheapest means for stabilizing its dimensions. For the investigation of the effect of thermal treatment on water repellency effectiveness and anti-swelling efficiency of beech wood (Fagus orientalis Lipsky), air-seasoned samples of beech wood were heated in presence of air at temperatures of 130 C, 150 C, 180 C and 200 C for different periods (2, 6, 10 h). Subsequently, the heated samples and their controls were immersed in water at 20 C, 65 % relative humidity for various periods. Percent of the tangential swelling and rate of the water absorption values of the test and control samples were determined for 2, 4, 8, 24, 48, 72 h on basis of oven-dried measurements. The heat treatment brought about a considerable reduction in water absorption and tangential swelling of the beech wood.
S Yildiz


Properties of hot oil treated wood and the possible chemical reactions between wood and soybean oil during heat treatment
2005 - IRG/WP 05-40304
Thermal treatment with hot oil as the heating media based on the original idea from oil-heat treatment in Germany was investigated. The treatment was mainly carried out at 200ºC and 220ºC for 2 hours and 4 hours, and the wood species were mainly spruce and fir. This paper focuses on the difference between soybean oil and palm oil and the possible chemical reactions between wood and soybean oil. Generally palm oil was slightly better than soybean oil in improving the moisture resistance properties of heat-treated wood. But soybean oil treated wood appeared to have better decay and mould resistance. The mass loss of wood treated in soybean oil at 220ºC for 4 hours was below 20 % after exposure to Gloeophyllum trabeum in a soil block test, so the treated wood can be classified as “Resistant” according to ASTM D 2017 standards. Natural weathering exposure also shows that soybean oil treated wood is more mould resistant than palm oil treated wood. In order to investigate the effects of absorbed oil on the properties of treated wood and the possible reactions between wood and oils, extraction of different vegetable oil treated wood with chloroform and other solvents was carried out. The results suggest that part of the soybean oil could undergo chemical reactions with wood that renders it of low extractability.
Jieying Wang, P A Cooper


Controlling marine borer attack of timber piles with plastic wraps
1981 - IRG/WP 479
Plastic films 20 to 40 mils thick have been used for many years to wrap creosoted timber piles in service to protect them from attack by marine borers. As long as the wrap remains undamaged, this procedure provides complete protection to the pile. Properly applied, wraps generally provide protection for 25 yeara or longer. Polyvinyl chloride (PVC) and polyethylene (PE) films are specially formulated for long service, especially in the intertidal zone where they are exposed to sunlight, wave action and abrasion. Carbon black and other inhbitors are used to prevent degradation from the sun's actinic radiation and embrittlement. The Port of Los Angeles requires a minimum carbon black content, film weight basis, of 1.5% for PVC and 2% for PE. The films differ in handling characteristics in water. PVC is tougher and more flexible than PE but tends to sink whereas PE lends to float. Initially PE is less flexible than PVC but, with time, PVC can lose its plasticizers becoming harder and more brittle than PE. PVC wraps have been in service about 25 years and PE wraps for 5 years with only scattered reports of polads (Martesia) penetrating PVC in Hong Kong, Panama and Brazil. The extent of attack appears slight. Films 10 mils or less in thickness can be damaged by crabs and other marine animals capable of grasping and tearing the film. Usually a diver wraps the film around and fastens it to a pile in place. A diver and a support crew of one or two persons wrap up to 250 linear feet of piles per day at a labor cost of over $900. Depending on diving conditions, the labor cost for wrapping piles ranges from $4.50 to $10.00 per linear foot of pile.
F Steiger, G Horeczko


Investigation of the suitability of silver fir (Abies alba Mill.) for thermal modification
2004 - IRG/WP 04-40275
In this study the suitability of silver fir (Abies alba Mill.) was examined for thermal modification. Comparative experimental investigations were performed with silver fir and Norway spruce (Picea abies Karst.) after thermal treatments. Besides properties, which characterize the quality of heat treatments, like dimensional stability and resistance against fungal attack, strength properties of the heat treated material were tested, i.e. bending strength, modulus of elasticity (MOE), impact bending strength and resistance to abrasion. Silver fir was found to be slightly more suitable for thermal modification than spruce, when treated at 180 °C, whereas thermal modification at 220°C showed a comparable suitability for both species. Advantages of silver fir were found for its impact bending strength, durability, and formation of cracks after weathering.
C Brischke, A O Rapp


Information from the COIPM Wood Group
1988 - IRG/WP 4146
Abstract from the COIPM minutes: Wood in marine environment: Mrs Gambetta stated that the main item discussed by the Group was the collaborative work to test the durability of heat shrinkable polyolephin sheating materials for the protection of wood against marine organisms. The work began last year when wood samples were sent out to the participants. Three samples of Pinus sylvestris wrapped in polyolephin supplied by Raychem were sent to the following participants: Mr. RASMUSSEN who put three stations at the disposal of the group: one in Denmark, one in Spain and one in India; Prof. RELINI with two stations: Rapallo and Loano in the Gulf of Genoa; Prof. GARETH JONES: Langstone station in England; Dr. GUEZENNEC: Tahiti Station; Dr. GAMBETTA and Dr. ORLANDI: Follonica station (Tyrrhenian Sea). The information regarding the physical and chemical characteristics of the stations as well as the most damaging marine organisms has been recived. The inspections regarding good or poor condition of samples have not yet been made but those in charge of the test would send the results as soon as possible. Dr. HABAL is also going to take part in the work and the samples would be sent out to him for exposure at his station. There was a second part in the collaborative programme: a study on the resistance to marine organisms of pressure treated wood with polymers. The tests with styrene are being undertaken. Preliminary tests were made at Follonica station but the bad results achieved prevented the group from extending the trials to other stations. The second item dealt with was the IRG/COIPM cooperative programmes. The first one regards different species of wood treated with CCA and CCB (Pinus, Alstonia, Fagus). The work already started nine years ago. Now it can be said that the two saline products gave results somewhat similar and chemical analyses have shown that Boron and Arsenic had a strong leaching therefore seems that a better protection is ensured by copper and chromium. The second one aims at studying the efficacy of polyurethane coatings on wood samples against marine organisms. The group also discussed the work in progress in the various member laboratories. Dr. HABAL informed on his tests on the behaviour of wood samples treated with TBTO and TBTF and also on the incorporation of antifouling materials into elastic paint like commercial preparation that can be applied as a thick layer onto wood pilings. He was also participating in the heat shrinkable plastic cooperative programme. Mr. DE PALMA was continuing his tests on polyolephin sheatings at his two stations and at other stations: Italy, Spain, India (stations of Follonica and Cadiz). He was also taking part in the IRG/COIPM collaborative programmes. Dr. GAMBETTA reported her tests carried out at Follonica on wood treated with organotins which were exposed in the marine environment during twelve years. She was also taking part in the IRG/COIPM cooperative programmes.
A Gambetta


Wood plastic composites from modified wood; Part 1 - Conceptual idea, mechanical and physical properties
2006 - IRG/WP 06-40338
Wood plastic composites, WPCs, are rapidly taking shares from preservative treated wood on the decking market. However, the long term performance of the WPC products in this application is uncertain. Therefore, in an attempt to increase the long term performance and durability, the substitution of the unmodified wood component with modified wood has been studied in the work presented in this paper. WPCs, with 70% wood content, from modified wood were successfully produced in semi-industrial scale. The wood component originated from acetylated and heat treated wood. WPCs from unmodified wood were also produced and used as references. Both acetylated wood and heat treated wood exhibits high durability and dimensional stability. Using modified wood in the WPC would not only increase the long time durability, but also enable a higher wood content, in high quality WPC products for exterior applications. The moisture sorption was significantly reduced for WPC with acetylated wood compared with WPC with unmodified wood. Also, for the WPC samples from heat treated wood, a reduced moisture sorption was observed. Microscope analysis clearly demonstrated the formation of cracks in the interface between unmodified wood and polymer matrix after water soaking and drying. No cracks were formed in the acetylated WPC samples. Improvements were also observed for the WPC samples from heat treated wood.
P Larsson Brelid, B K Segerholm, M Westin, M E P Wålinder


Wood plastic composites from modified wood. Part 2 - Durability in laboratory decay tests
2006 - IRG/WP 06-40353
The decay resistance of wood plastic composites, WPCs, was tested according to modified versions of AWPA E10 (soil-block test) and ENV 807 (tests in three un-sterile soils, terrestrial microcosms, TMCs). The WPC materials were conically extruded profiles with 30% polypropylene content. The 70% wood content was untreated Scots pine sapwood, acetylated pine and heat treated Norway spruce, respectively. In the first set of soil-block test control WPC with 70% untreated pine performed poorer than the pine sapwood controls. The fungal preference for the WPC material could be seen in the soil-jars where the WPC blocks were covered with more mycelium than the solid pine blocks. However, the WPCs with 70% acetylated wood were highly resistant to decay. In the TMC tests, the WPC materials with unmodified wood performed better than in the soil-block test but poorer than the two types of WPCs from heat treated spruce and acetylated pine particles. Again, the WPC with 70% acetylated pine particles was practically unattacked.
M Westin, P Larsson Brelid, M L Edlund, G Alfredsen


Relationships between heat treatment intensity and some conferred properties of different European softwood and hardwood species
2012 - IRG/WP 12-40593
Effect of treatment intensity on conferred properties like elemental composition, durability, anti swelling efficiency (ASE) and equilibrium moisture content (EMC) of different European softwood and hardwood species subjected to mild pyrolysis at 230°C under nitrogen for different durations has been investigated. Independently of the wood species studied, elemental composition is strongly correlated with the mass losses due to thermal degradations which are directly connected to treatment intensity (duration). In all cases, an important increase of the carbon content associated with a decrease of the oxygen content was observed. Heat treated specimens were exposed to several brown rot fungi and the weight losses due to fungal degradation determined after 16 weeks, while effect of wood extractives before and after thermal treatment was investigated on mycelium growth. ASE and EMC were also evaluated. Results indicated important correlations between treatment intensity and all of the wood conferred properties like its elemental composition, durability, ASE or EMC. These results clearly indicated that chemical modifications of wood cell wall polymers are directly responsible for wood decay durability improvement, but also for its improved dimensional stability as well as its reduced capability for water adsorption. All these modifications of wood properties appeared simultaneously and progressively with the increase of treatment intensity depending from treatment duration. At the same time, effect of extractives generated during thermal treatment on Poria placenta growth indicated that these latter ones have no beneficial effect on wood durability.
M Chaouch, S Dumarçay, A Pétrissans, M Pétrissans, P Gérardin


Proposal for further work on accelerated ageing
1988 - IRG/WP 2314
M-L Edlund


A practical method to evaluate the dimensional stability of wood and wood products
1990 - IRG/WP 2342
This paper presents a new simple method to evaluate wood and wood products for their resistance to swelling and to assess wood preservatives for their ability to dimensionally stabilize treated wood exposed to water. Permeable wood of various dimensions and treated with different preserving chemicals have been measured for swelling in the radial and tangential direction during immersion in liquid water. The results indicate that a simple exponential function describing the dimension of the samples during immersion can be used to evaluate both the water-repellency and anti-swelling effectiveness of wood preserving chemicals. The results can be achieved in reasonable time, and the parameters of the function can be determined by a commercial desk-top computer program.
J P Hösli


Effectiveness of "Gang-Nail" plates in preventing splitting of Eucalyptus poles and Brazilian hardwood sleepers
1984 - IRG/WP 3262
This paper presents the results of some tests carried out with an anti-splitting device, placed on the end surfaces of Eucalyptus spp utility poles and Brazilian hardwood sleepers at the beginning of an air-drying period. The type of device used, a "Gang-Nail" plate, reduces significantly the splits at the end-surface of poles, but reduces only a little the splits occurring in sleepers.
A M F Oliveira, J A C Sodré, O B Neto


Thermal treatment of wood: European Processes and their background
2002 - IRG/WP 02-40241
Recent efforts on thermal treatment of wood lead to the development of several processes introduced to the European market during the last few years. The total production capacity of heat treated wood in 2001 is estimated as approx. 165.000 m3. In the paper the different heat processes are presented. The general technology as well as scientific data on the chemical transformation of the cell wall polymers, on the biological performance, on the physical and mechanical properties of the treated wood are presented and discussed
H Militz


Durability of pine modified by 9 different methods
2004 - IRG/WP 04-40288
The decay resistance was studied for pine modified by nine methods of wood modification: 1) Acetylation, 2) Treatment with methylated melamine resin (MMF), 3) Acetylation followed by post-treatment with MMF-resin, 4) Thermal modification, 5) Furfurylation, 6) Maleoylation (using water solution of MG or ethanol solution of maleic anhydride), 7) Succinylation, 8) NMA-modification and 9) modification with reactive linseed oil derivative (UZA), Wood blocks of Scots pine (Pinus sylvestris L.) sapwood were modified in pilot plants. Methods 1-5 were performed by the authors at Chalmers University of Technology or at BFH in Hamburg. Methods 5-9 were part of a European research project (the Chemowood project, FAIR-CT97-3187) and therefore each of these modifications was performed by the project participant responsible for the method. For laboratory testing in TMCs (modified European standard ENV 807) and pure basidiomycete culture bioassays, smaller test specimens were cut from the modified wood blocks. Most of the modification methods were applied on test specimens for marine field testing (EN 275) and some methods to produce mini-stakes for field tests in five Swedish fields. Some modification methods result in modified wood with poor durability, whereas other methods (acetylation, furfurylation and MMF-treatment) seem to provide excellent resistance to microbial decay.
M Westin, A O Rapp, T Nilsson


Commercially available anti-sapstain chemicals in New Zealand - An update
1987 - IRG/WP 3416
Six anti-sapstain chemicals or mixtures (NaPCP plus borax, Haipen 5F, Mitrol PQ375, Busan 1009, Protek S, Pinefol 50W) are available as commercial treatments in New Zealand. A further two (Hylite 20F and Isothon-35) have shown potential in field and mill trials and will be available for use. A number of other formulations are under evaluation.
J A Drysdale


Nouvelles techniques de lutte anti-termites à faible impact environnemental
1995 - IRG/WP 95-50040-32
P Martinet


Mould resistance of lignocellulosic material treated with some protective chemicals
1984 - IRG/WP 3294
Effectiveness of preserving lignocellulosic material against moulding by treatement with water solutions of commercial wood preservatives and mixtures of various inorganic salts was investigated and compared with the effectivenes of sodium pentachlorophenoxide and boric acid.
K Lutomski


Field trials of anti-sapstain products. Part 1
1991 - IRG/WP 3675
The results obtained in two field tests of anti-sapatain products, carried out in four locations in Portugal, are presented. Boards from freshly cut logs were hand-dipped, close staked and left to dry for periods from four to six months. The results obtained seem to indicate that some of the products tested performed at least as well and sometimes better, than a 3% NaPCP solution which was used as control product.
L Nunes, F Peixoto, M M Pedroso, J A Santos


In search of alternative antisapstain chemicals for use in Papua New Guinea
1988 - IRG/WP 3472
The paper presents results of antisapstain field trials from three locations in Papua New Guinea as part of the Research Centre's programme to find suitable antisapstains to replace the hazardous sodium pentachlorophenate. Effectiveness of seven tested chemicals varied between indigenous pines (Araucaria cunninghamii, Araucaria husteinii) and white coloured hardwoods (Alstonia scholaris, Pterocymbium beccarii) but not between sites. The indigenous pines required lower chemical concentration for same level and period of protection than white coloured hardwoods like amberoi and white cheesewood. Period of protection ranged from four weeks to a maximum of 16 weeks depending on chemical concentration and species of timber. Potential chemicals recommended for use as antisapstain include Celbrite T, Busan 1009, Penacide and Woodguard E.S. and Woodguard E.C.
A Oteng-Amoako


Observations on the colonization of freshly-felled timber treated with prophylactic chemicals by mould and sapstain fungi
1989 - IRG/WP 1394
Field tests using freshly felled pine sapwood were set up to determine the effectiveness of a range of antisapstain compounds and to study the problems of colonization by mould and sapstain fungi. Differences were recorded both in the overall performance of the compounds and also their selectivity in controlling specific fungal types. These results were found to be useful in gaining a better understanding of biocide - fungal interactions.
G R Williams, D A Lewis


Proposed standard laboratory method for testing fungicides for controlling sapstain and mould on unseasoned lumber
1977 - IRG/WP 292
This laboratory method is for determining the effective concentration, or concentration for zero growth (CGo), for fungicides or preparations of fungicides which are potentially useful in protecting packaged or unseasoned lumber in storage and shipment from biodeterioration by sapstain fungi and moulds. The test is rapid and may be completed in three weeks and gives a good indication of the toxicity of a chemical against sapstain fungi and moulds.
A J Cserjesi


Selective adsorption of antisapstain actives from two aqueous suspensions, and movement of actives into wood
1996 - IRG/WP 96-30103
Green-off-saw rough sawn Pinus elliottii (slash pine) boards were dipped in aqueous suspensions of two antisapstain formulations, NeXgenâ and Busanâ Sap Stain Preventative (Busan 1009), at three product concentration levels. Concentrations of active ingredients (NeXgen: CTL (chloro-thalonil) and MTC (methylene bisthiocyanate); Busan 1009: TCMTB (2(thiocyanomethylthio)-benzothiazole) and MTC) were monitored with respect to the amount of material dipped. Selective adsorption (removal of actives from the suspension at greater than simple volumetric transfer rates) varied with formulation and active ingredient, and increased with decreasing product concentration. Movement of active ingredients into dipped boards was monitored for 30 days after dipping. Mobility order was MTC >> TCMTB > CTL. Surface depletion characteristics were obtained for each active ingredient.
M J Kennedy, T L Woods


Corrosion of fasteners in heat-treated wood – progress report after two years’ exposure outdoors
2005 - IRG/WP 05-40296
The corrosion of common fastener materials now in use - mild steel, zinc-coated steel, aluminium and Sanbond Z-coated steel – has been evaluated after two years’ exposure outdoors in untreated and heat-treated spruce (Picea abies) respectively. Spruce from South-western Sweden was used. The heat-treatment was carried out in Finland according to the ThermoWood process at a maximum temperature of 220 °C for five hours. The results so far show that the corrosion of fasteners in heat-treated wood according to the particular specification is more severe than in untreated wood. Mild steel and zinc-coated steel has been most susceptible. Stainless steel is hardly attacked at all.
J Jermer, B-L Andersson


Evaluation of the effectiveness of three microbiocides in the control of sapstains
1982 - IRG/WP 3212
Results of field test on the effectiveness of BUSAN 30, CAPTAN, FOLPET against mould and sapstain in Pinus elliottii are presented. The viability of use of FOLPET in Brazil as an alternative to sodium pentachlorophenate is also discussed.
S Milano, J A A Vianna Neto


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