Your search resulted in 34 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
Biological screening assays of wood samples treated with creosote plus chemical additives exposed to Limnoria tripunctata
1980 - IRG/WP 408
Laboratory methods for exposure of treated wood coupons to Limnoria tripunctata are described. Chemical additions to creosote were screened using this method. Three pesticides, Endrin, Kepone, and Malathion proved particularly effective. The addition of varying percentages of naphthalene to creosote using several treatment methods are currently being assayed. Results to date show that the coupons treated by the empty cell method have better performance than those prepared by the toluene dilution method. The naphthalene coupons treated by the full cell method show no attack after six months' exposure.
B R Richards, D A Webb
Effect of protective additives on leachability and efficacy of borate treated wood
2002 - IRG/WP 02-30290
Borate preservatives have been used extensively in many countries as an effective means for protecting wood against fungal and insect attack especially in interior environments. Under exterior conditions, borate compounds have a main disadvantage as they can be leached from treated wood as a result of their water solubility. In this study, we compared the potential of different additives for reducing the leachability of boron preservatives from treated wood. Scots pine sapwood (Pinus sylvestris) and poplar (Populus trichocarpa x deltoides) test samples were vacuum treated with 1 % BAE (Boric Acid Equivalent) disodium octaborate tetrahydrate (DOT) solutions containing various additives e.g. glycerol/glyoxal, polyvinylpyrrolidone (PVPY), a commercial resin compound and a commercial water repellent. The European Standard EN 84 was used as a leaching test for both coated and uncoated specimens. The results of chemical analysis of leachates taken at different periods showed that the use of protective additives reduces the boron leachability. The glycerol/glyoxal additive applied to treated pine sapwood showed the best performance. The percent of boron retained in uncoated pine sapwood was 26% while coated samples still retained 45% after 14 days of intense leaching. Similar tests on poplar revealed 19% and 34% for uncoated and coated samples, respectively.This represents a gain of 20 to 25% compared to pure DOT treated specimens of both wood species. Preliminary biological tests were carried out on malt agar using a miniblock technique for uncoated pine sapwood and beech, with Poria placenta and Coriolus versicolor, respectively. After six weeks of exposure to fungal attack all boron protective systems tested proved their effectiveness, as none of the test samples exhibited a mass loss exceeding 4%. The reference 1% BAE without protective additives showed an average mass loss of 15%. Finally, test data are reported of standard EN 113 testing in view of a further evaluation of the biological efficacy of combined DOT-additive treatments.
A Mohareb, J Van Acker, M Stevens
Water-repellent additive for CCA
1991 - IRG/WP 3655
Hickson have developed a water repellent additive for incorporation into copper-chromium-arsenate timber treatment solutions. The water repellent emulsion shows good stability in the treatment solution, is easily incorporated and applied in a single stage treatment. No modifications to the additive is safe to treatment schedule are usually needed and use. Weathering of the treated wood is substantially inhibited by the presence of the additive. Adhesion of paints is not affected.
P Warburton, R F Fox, J A Cornfield
Improved PEC preservatives with added biocides
1985 - IRG/WP 3322
Biocidal chemicals have been incorporated into formulations within the broad framework of pigment emulsified creosote (PEC) to provide novel potential multi-purpose preservatives. Preparations of PEC plus TCMTB, Boracol 40, copper ethanolamine nonanoate, Quatramine 80, arsenic trioxide, Troysan Polyphase, and CCA have been formulated and assessed for preserving ability in soil-jar and Accelerated Field Simulator tests. In addition, a cationic oil-in-water emulsion preservative combination of PEC and CCA (PECCA), and an anionic formulation of TCMTB with PEC (PECBUS) have been manufactured in 400 L quantities to treat hardwood pole stubs and pine posts. The results indicate the potential of these improved second generation PEC-based preservatives to provide low-creosote containing treatments able to protect commodities against biodeterioration as well as provide dry, clean surfaces.
H Greaves, C-W Chin, J B Watkins
Long-term performance of a "wax" type additive for use with water-borne pressure preservative treatments
2000 - IRG/WP 00-40159
Field performance results are updated for matched CCA treated decking boards with and without an emulsion water repellent additive incorporated with the initial pressure treatment. Decks have been exposured for over 9 years in Harrisburg, NC. Boards were evaluated for in-service and laboratory performance for water repellent efficacy, as well as additive loadings in the boards after this exposure. All results support that these additives can provide long-term protection against many of the physical defects that develop in pressure treated wood during exposure.
A R Zahora
Biological effectiveness of ground-contact wood preservatives as determined by field exposure stake tests
1984 - IRG/WP 3297
Field exposure tests conducted on stakes treated with different creosotes, mixtures of creosote and waxy oil as well as different CCA wood preservatives over a period of 25 years, gave the following results: The CCA preservatives provided excellent biological protection to treated stakes, especially against fungal attack. The CCA Type I, currently approved for use under South African conditions is not inferior to the CCA Type II during long-term ground-contact exposure if the active elemental contents and effective retentions are taken into consideration. The creosotes provided good protection against termite attack but showed fairly poor fungal resistance during long-term ground-contact exposure under wet conditions. The addition of waxy oil greatly improved the effectiveness of creosotes against fungal attack. The CCA preservatives proved to be a better overall ground-contact preservative compared with the creosotes.
W E Conradie, A Pizzi
The effect of selective additives and conditions on the decomposition of Basamid in Douglas fir heartwood
1992 - IRG/WP 92-3698
Basamid is a solid, powdered chemical used as an agricultural soil fumigant. Decomposition of Basamid isothiocyanate, hydrogen sulfide, methyl amine, and formaldehyde. Basamid has some potential as a wood fumigant, but it decomposes too slowly to be effective. Various additives and conditions were tested for their ability to enhance Basamid decomposition in Douglas-fir heartwood. Higher MC's and temperature, as well as copper sulfate and powdered pH 12 buffer increased decomposition rates with copper increasing the efficiency of breakdown to form MITC.
P G Forsyth, J J Morrell
Bending creep test of plywoods under long term exposure to fungal attack
1981 - IRG/WP 2163
Bending creep test and decay test were coupled in order to evaluate the durability of structural plywoods and preservative efficacy. Experimental blocks, 5.0 x 1.2 cm² section x 35.0 cm length, were impregnated with distilled water and inoculated with mycelial fragments of test fungus. Polyethylene bags stretched with metal frame were used as decay chambers. The chambers containing inoculated blocks and water were plugged with porous silicone plugs. Weight was hanged from the center of block. The deflection at the center of span was measured with a gauge sensor connected with a recorder. The deflection due to fungal attack appeared after 800-1200 hrs incubation. Non-treated plywoods failed by 2400 hrs. Treated plywoods containing 1 kg/m³ of TBP (Tribromophenol) did not fail even after 3800 hrs but deflected continuously. When containing 5 kg/m³ of TBP, only a slight deflection was observed. Based on the assumption that decay advanced uniformly in the parallel direction to the span but wavy like as cosine curve in the perpendicular one, creep deflections were calculated and compared with the experimental ones. It may be concluded from these results that the method is promissing for evaluating the durability of structural board materials and preservative efficacy.
The effect of water-repellent additives on the leaching of CCA from simulated southern Yellow pine decks
2000 - IRG/WP 00-50158
End-matched SYP boards were pressure-treated with CCA or CCA in combination with commercial water repellent additives. After fixation and drying, the boards were placed in plastic boxes and exposed outside in Harrisburg, NC. Plastic supports were used to keep the boards above the water collected. Over a period of five months, rain run-off water from 14 natural rainfalls were collected and analyzed by ICP. Metal leachate level was related to the type and level of water repellent additive present. Two commercial water repellents, which had much better water repellency than the third product, were found to be effective in reducing CCA leaching. Arsenic leaching can be reduced by over 35% in the presence of 1.2% of the two effective water repellents.
F Cui, P J Walcheski
Effect of alkaline phenolic resin adhesive on the stability of preservatives incorporated into the glue-line of plywood
1991 - IRG/WP 3650
Stability of preservatives was determined by gaschromatographic analysis when they were applied to glue-line treatment of plywoods. Among organophosphorous insecticides, emulsified forms of chlorpyrifos, dichlofention and diazinon were more stable than others. Fenitrothion, pyridafenthion and phoxim were not practically acceptable as emulsifieable forms due to the relatively low recovery rates after an accelerated ageing (heat exposure at 60°C after hot-press). IF-1000, an organoiodine fungicide, seemed to be less stable under the influence of heat, although the fungicide was better than the other tested organoiodine chemical (Sunplas).
S Fushiki, Y Katuzawa
The effect of glycol additives on diffusion of boron through Douglas-fir
2000 - IRG/WP 00-30235
Boron is highly effective against a variety of fungi and insects and is able to diffuse with moisture through wood. Diffusion decreases sharply at lower moisture contents, a characteristic that limits the potential use of this material as a remedial treatment for arresting internal decay. One approach to improvi ng boron diffusion is the simultaneous addition of glycol, which is presumed to enhance boron diffusion. In this study, the potential effects of glycol addition were explored by adding glycol plus boron (Boracol 20®, Boracol 40® or BoraCare®) or Timbor® and fused boron (Impel rods®) to produce a desired boric acid equivalent in each pole. Boron movement was assessed by periodically removing increment cores for chemical analysis. All of the supplements improved the diffusion of boron through Douglas-fir wood. Timbor®, which does not contain glycol, resulted in the most even distribution of boron throughout the poles while Boracol 40® seems to have increased boron diffusion to the point of loss from the poles.
C M Freitag, R Rhatigan, J J Morrell
Test methods for wood preservatives against Lyctus: (1) Testing of treated veneer. (2) Testing of glue-line treated plywood. (Laboratory methods)
1977 - IRG/WP 293
Powder-post beetles destroy large quantities of veneer and plywood. Two test procedures are described which can be used to support application-oriented research into veneer and plywood preservatives. These procedures simulate practical conditions on a laboratory scale. Their characteristic feature is that wood species of special susceptibility are used for the tests; the susceptibility of the specimens is ensured via pre-treatment with Lyctus nutrients.
Properties-enhanced albizzia particleboards by incorporating fungicide and insecticide in the glue
1994 - IRG/WP 94-30060
Preservative-treated particleboards were prepared by using tropical fast-growing albizzia and adding fungicides and insecticides to the adhesive-glue. the physical and biological properties of these boards were evaluated. No significant reduction in bending or internal-bond strength due to incorporation of the chemicals was detected. Treated particleboards effectively resisted attack by Coptotermes formosanus at an active ingredient (a.i.) retention of less than 0.5 kg/m³ for chlorpyrifos, dichlorophenthion and propetanphos in laboratory tests. Although decay was unaffected by incorporating the mixed preservative at the retention levels in this study, boards which contained IF-1000 as a fungicide an an a.i. retention of more than 1.0 kg/m³ showed the possibility of decay resistance.
B Subiyanto, S Yusuf, Y Imamura, S Fushiki, T Saito, T Katuzawa
A field trial of water repellents as anti-sapstain treatment additives
1987 - IRG/WP 3417
The assessment of water repellents as anti-sapstain treatment additives has been included in a recent FRI research programme investigating improved surface protection of New Zealand Pinus radiata. Laboratory work has shown variation in water repellent effectiveness with chemical type and subsequently a field trial was established to examine the performance of selected water repellent/anti-sapstain treatments. Three water repellents were tested in combination with either sodium pentachlorophenoxide plus borax, Busan 1009 (methylene bisthiocyanate plus 2-(thiocyanomethylthio) benzothiazole), or Mitrol PQ375 (copper-8-quinolinolate). Although inspection of treated wood packages after 3 months' outside storage showed little variation in performance, inspections after 6 months showed that wood treated with formulations incorporating a paraffin wax emulsion was drier and usually showed less fungal degradation than wood treated with unamended anti-sapstain solutions.
J A Drysdale, D V Plackett
Further progress towards a cleaner creosote treatment - Summarised report
1984 - IRG/WP 3304
This document provides an up-dated progress report on our development of pigment emulsified creosote (PEC) used as a cleaner alternative to conventional high temperature creosote. A range of commodities (both hardwood and softwood) has now been satisfactorily treated in pilot plant and full scale commercial operations. Both brown (PEC 30B) and white (PEC 30W) formulations have been used. In addition a number of biocides have been added to PEC 30B in order that wood may be treated to lower overall creosote levels while still retaining full preservation performance. It is anticipated that PEC will be used to treat a wide range of hardwood and softwood commodities.
H Greaves, C-W Chin, J B Watkins
Comparative field performance of CCA and CCA-water repellent treated Southern pine lumber
1995 - IRG/WP 95-30089
This paper describes the field performance of end-matched southern pine boards treated with either CCA type C or CCA type C containing an emulsion water repellent (WR) additive. Boards were either kiln or air-dried after treatment, constructed into decks, and exposed for over 3 years at Harrisburg, NC. During this exposure, matched boards were monitored for internal moisture content, cupping at midpoint, checking, and degree of nail pull. The CCA-only treated boards display rapid changes in moisture content, check width, and degree of cupping that was directly influenced by rainfall. Although boards treated with CCA and the water repellent additive are starting to lose the characteristic of surface water beading, the boards continue to show greatly improved in-service dimensional stability compared with matched CCA-only treated boards. The effectiveness of the water repellent additive in reducing physical degrade during service exposure is manifested in greatly reduced check development and nail pull when compared to the CCA-only treated boards.
A R Zahora
Interactions between water-borne preservatives and emulsion additives that influence the water repellency of wood
1991 - IRG/WP 2374
Incorporation of non-polar additives into water-borne treatments through of emulsion technology can greatly improve the physical characteristics of wood in service. Of specific interest with these emulsions is their effectiveness in reducing the rate of wood swelling. We have observed that the presence or absence of preservatives can often significantly influence the resultant effectiveness of the water repellents when measured in an immersion swelling test. This paper describes some preliminary results of experiments comparing the relative effectiveness of a water repellent additive when used in combination with CCA-C as well as the effect of preservative concentration on water repellency.
A R Zahora
Preservation of wood-based panels against fungi and insects and and testing its efficiency
1976 - IRG/WP 270
Wood-based panel products which are made of susceptible wood species may be destroyed by fungi under wet conditions and by termites. The glues do not provide sufficient protection unless very high concentrations are applied. Particle boards and fibre boards are not susceptible to beetle infestation, although some species may attack plywood. Various types of preservatives provide sufficient protection of panel products. These are boron, fluoride, copper, and chromium compounds in the category of water-soluble salts and various organic compounds, including contact insecticides, in the category of nonwater-soluble substances. Their application is influenced by their compatibility with the glue and by the different methods of treatment. For the production of fibreboards oil-borne preservatives are preferred. With regard to particle boards and plywood it is recommended to apply the required preservative loadings prior to the pressing operation, to mix them with the glue or to impregnate the particles or plies and with regard to fibreboards to spray the pressed and cooled down panels with the preservative. The fungus cellar test is the most suitable method for testing the efficiency of a chemical treatment of panel products against fungal attack. With regard to beetle species European standard methods of test are available. There are also laboratory and field methods for evaluating the resistance against termites. Treatment standards are controlled by chemical methods of analysis.
G Becker, M Gersonde
Standard and accelerated testing of boron-additive wood protection systems
2005 - IRG/WP 05-30381
The main objective of this research was to determine the effectiveness of boron-additive protection systems for above ground applications by means of field testing. The two field test procedures used are based on the L-joint test described in the European standard EN 330. For the first set up the boron treated timber was coated in accordance with the standard EN 330 system. The second set up is based on an accelerated test simulating uncoated applications and includes an additional moistening of the jointing area. After three years of aboveground exposure, boron preservatives are still providing an adequate protection to coated L-joint specimens. Based on the results obtained it can be concluded that boron-based compounds still provide good protection after three years of natural weathering when protected by a three-coat finish. Similar uncoated L-joints treated the same way show rapid deterioration under the accelerated exposure conditions applied. The mass loss data revealed a significant level of decay for the uncoated specimens even when treated with boron-additive formulations. This is attributed to the high leaching hazard related to the accelerated exposure method used. The latter proves to be too aggressive for all tested boron-based preservatives when unprotected by surface coatings. A treatment with 1 % CCA under the same conditions was still performing adequately after 3 years even under accelerated L-joint exposure of uncoated test samples.
A Mohareb, J Van Acker, M Stevens
Future insecticidal treatments for wood products
1980 - IRG/WP 3140
Protective measures involving chemical treatment of wood use only a narrow range of toxic materials which are divisible into two groups, (i) those that are water-soluble, (ii) those that are soluble only in organic solvents. It is generally true to say that, as far as protection against insects is concerned, the former are stomach poisons while the latter are largely (though not exclusively) contact poisons (i.e., the commonly termed "insecticides"). In both groups, the most frequently used materials are currently under some pressure because of environmental considerations, but economic problems, related to supply of raw materials, also exist. In common with other organisations involved with the preservation of wood products, the N.Z. Forest Research Institute has recently put a lot of emphasis on finding new, or alternative, treating systems and this paper presents the entomological aspects of the work to date.
D J Cross
Laboratory evaluation of water repellents as antisapstain treatment additives
1986 - IRG/WP 3382
Water repellent formulations consisting of five paraffin wax emulsions, three polyethylene wax emulsions, two polybutadiene resin emulsions, a polyester emulsion, and a ß-pinene polymer emulsion were subjected to water repellency tests on radiata pine sapwood. With one exception, the parafin wax emulsions were more effective water repellents than the alternative formulations and one of the paraffin wax emulsions (Paracol 800A) was selected for inclusion in laboratory antisapstain tests. The results showed there was no improvement in fungicidal effectiveness of NaPCP/borax, Busan 1009 (Buckman Laboratories), or Mitrol PQ375 (Kenogard) with addition of this water repellent.
D V Plackett, C M Chittenden
Influence of water-borne preservatives on water repellency and the impact of addition of water repellent additives
1992 - IRG/WP 92-3704
The primary goal of a desirable wood preservative system is to effectively control decay fungi and other biodeteriogens in service. The water repellent nature of a given system may play an important role in the protection of wood. In this study, the water repellency of several water-borne preservative systems has been evaluated by measurements of tangential swelling during immersion. The systems include cuprammonium formulations, such as ammoniacal copper carbonate (AC) and ammoniacal copper zinc arsenate (ACZA), ammoniacal copper quat systems (ACQ) and chromated copper arsenate (CCA). The influence of addition of water repellent emulsions into the above systems has also been examined.
L Jin, D M Roberts, A F Preston
Methods to determine the efficacy of three water repellent additives in waterborne preservatives
1997 - IRG/WP 97-30142
The paper describes the methods used to determine the efficacy of three different water repellent additives in waterborne preservatives. The wooden samples used are pine (Pinus sylvestris) and spruce (Picea abies) that are treated with 9 different waterborne preservatives in retention for hazard class 3 (above ground commodities). There are two sample sizes exposed, cladding boards (19 x 148 mm) with a sawn surface exposed 60 ° facing south, and decking boards (21 x 95 mm2) with a planed surface exposed horizontally. The boards' dimensions have been measured and water repellent properties have been checked three times with water droplets during exposure in 2.5 years. During the winter 1996/1997 and spring 1997 we have logged the temperature and moisture content in eight of the boards for one of the additives; also with and without preservative (CCA). We log every half hour. The RF is also logged. This paper will in addition to describing the methods also give the results after 2.5 years, while a subsequent paper will give the results for the efficacy of the different additives.
F G Evans, B Nossen, K M Jenssen, L R Wilhelmsen, G Fuglum
Glue-line additives for protecting plywood. A review
1978 - IRG/WP 2102
The conclusions of this review are: 1) Insecticidal glue-line additives can be used satisfactorily to protect plywood against insect attack. 2) It is uncertain, in spite of some claims, wether fungicidal glue-line additives can be similarly used to protect plywood against fungi under damp conditiones. There is a need for further work to validate the mycological tests that may be used to investigate this claims. 3) In addition, there is a need to gain experience on the in situ behaviour of glue-line additives and it is proposed that field trials be initiated to determine their ability to protect plywood over a long period.