Your search resulted in 81 documents. Displaying 25 entries per page.
Properties and potential use of Irvingia gabonensis and Irvingia wombolu kernel extracts as natural wood adhesives: Towards formaldehyde free wood composite products
2018 - IRG/WP 18-40832
Irvingia species are widely distributed in central and West Africa as well as parts of Asia and are earmarked for domestication due to the multitude of potential products that can be obtained from them. With renewed interest in renewable sources, the current study establishes the feasibility of utilizing extracts from Irvingia gabonensis and Irvingia wombolu kernels as wood adhesives. Proximate an...
A O Alawode, S O Amiandamhen, M Meincken, L Tyhoda
Paintability and gluability of wood treated with arsenic-free and chromium free preservative treatments
2006 - IRG/WP 06-40342
The objective of this project was to study, in comparison with traditional CCA treatment, the paintability and gluability of wood treated with arsenic-free and chromium-free preservative treatments.
Four formulations, all certified CTB P+, were selected in accordance with their representativeness of the preservative product market: one CCA reference formulation and three chromium and arsenic free...
L Podgorski, G Legrand
Fungal decay resistance and mechanical properties of plywood panels made from maritime pine (Pinus pinaster) and bonded with cornstarch-quebracho tannin-phenol formaldehyde adhesive
2010 - IRG/WP 10-40490
The aim of this work is to demonstrate the performances of cornstarch-quebracho tannin-based resins designed as adhesive in the plywood production. In this way, the cornstarch and quebracho tannin was introduced in the classic adhesive formulation in order to supply a part of phenol-formaldehyde (PF). In order to evaluate the mechanical performances of optimal cornstarch-quebracho tannin-PF, plywo...
F Charrier, A Moubarik, A Allal, A Pizzi, B Charrier
Biological and mechanical performances of particleboard panels made from maritime pine (Pinus pinaster) and glued with cornstarch-mimosa tannin-urea formaldehyde adhesive
2011 - IRG/WP 11-40542
The objective of this work was to demonstrate the utility of cornstarch-mimosa tannin-based resins designed for application as an adhesive in the particleboard production. Bond qualities of cornstarch-mimosa tannin- urea formaldehyde (UF) (10:4:86, weight ratios) resins and commercial UF resin were assessed by using an automatic bonding evaluation system, prior to production of particleboard panel...
A Moubarik, F Charrier, A Pizzi, A Allal, B Charrier
Curing kinetics of nano cupric oxide (CuO) modified PF resin as wood adhesive: Effect of surfactant
2013 - IRG/WP 13-40620
The effect of nano cupric oxide (CuO) in combination with surfactants on the curing kinetics of phenol formaldehyde (PF) resin, as well as the bonding strength of plywood prepared using the modified resin were investigated in this study using dynamic and isothermal differential scanning calorimetry (DSC). The result showed that the incorporation of nano CuO along with alkane surfactant made in the...
Wei Gao, Guanben Du
Lignin-Based Adhesive for Engineered Wood Products
2016 - IRG/WP 16-50319
Lignin as a naturally occurring polyphenolic compound has an excellent potential to replace petroleum-based phenol in formulation of phenol-formaldehyde adhesive that are used in manufacturing of engineered wood products. However, there are three major obstacles in application of polymeric lignin as phenol replacement: 1) low reactivity toward phenol, 2) high molecular weight, and 3) high polydisp...
I Kalami, M Arefmanesh, E Master, M Nejad
Physical and biological properties of albizzia waferboards modified with cross-linking agents
1995 - IRG/WP 95-40043
Chemically-modified low-density waferboards with cross-linking agents were produced using a fast-growing species of hardwood albizzia (Paraserienthes falcata Becker) as a raw materials and isocyanate resin as a glue adhesive. For the chemical modification, the vapor-phase formalization of the boards and the pad-dry-cure treatment of wafers with cross-linking agents were employed. The vapor-phase f...
S Yusuf, Y Imamura, M Takahashi, K Minato
Oxygen index levels and thermal analysis of wood treated with melamine-formaldehyde-boron combinations
1997 - IRG/WP 97-30135
Melamine formaldehyde (MF) resin was impregnated into scots pine (Pinus sylvestris L.) specimens with aqueous solutions of 5, 10 and 20% concs. Boric acid (BA) and borax (BX) was added to MF resin at the concentration levels of 0.25, 1.00 and 4.70% to each level of resin concs. BA and BX mixture was prepared at the 5:1 (w/w) ratio considering resultant pH of solutions and better fire resistance. U...
M K Yalinkilic, W-Y Su, Z Demirci, E Baysal, M Takahashi, S Ishihara
Susceptibility of angiosperm sapwood to white-rot fungal colonization and subsequent degradation: a hypothesis
1997 - IRG/WP 97-10211
It has long been recognized that angiosperm sapwood in nature is relatively easily and preferentially degraded by white-rot fungi. This susceptibility to white-rot fungi is generally believed to be mainly caused by the structure and concentration of angiosperm lignin. However, an explicit explanation as to why lignin structure makes a particular wood vulnerable to white-rot colonisation and subseq...
T Schultz, D D Nicholas
Combined effects of the treatment of wood with formaldehyde
1978 - IRG/WP 3117
Treatment of fibrous materials with reagents in a vapor phase is neither new nor unique. Numerous examples exist in literature of vapor phase experiments on cellulose fibers and fabrics, and on wood. For many years the textile research and industry have used vapor phase processes for the treatment of textiles. The chemical modification of cellulose is based on different types of reactions e.g. est...
M Stevens, J Schalck
Thermotolerant mould growth in dehumidifier kilns in New Zealand
1996 - IRG/WP 96-10169
Growth of Aspergillus fumigatus and Paecilomyces variottii is common on wood dried in dehumidifier kilns that operate within a temperature range of 35-55°C. Aspergillus fumigatus causes an unacceptable blue / grey discolouration of the woods surface and prolonged exposure to spores during handling of mouldy wood can cause health problems amongst timber workers. A survey of dehumidifier kiln opera...
R N Wakeling, J G Van der Waals
The effect of low molecular weight chelators on iron chelation and free radical generation as studied by ESR measurement
2000 - IRG/WP 00-10367
The focus of this work was to improve our current knowledge of the non-enzymatic mechanisms involved in brown-rot decay. Electron Spin Resonance (ESR), also known as Electron Paramagnetic Resonance (EPR), is an attractive technique for the identification and study of chemical species containing unpaired electrons (such as radicals and certain transition metal species). ESR spin-trapping techniques...
Yuhui Qian, B Goodell
The use of ESR spectroscopy to assess the photostabilising effects of wood preservatives
2000 - IRG/WP 00-20186
The degradation of wood surfaces exposed to UV light which leads to poor performance of clear coatings is understood to be due to delignification via a mechanism involving free radicals. Certain wood preservatives most notably CCA are able to photostabilise wood and therefore they may reduce the concentration of free radicals formed when treated wood is exposed to ultraviolet light. As a first ste...
S Schmid, R D Webster, P D Evans
Effects of a formaldehyde and sulphur dioxide treatment on decay and mechanical properties of aspen waferboard
1983 - IRG/WP 3242
Aspen wafers were sequentially treated under vacuum with formaldehyde and sulfur dioxide gas and pressed into waferboard bonded with powdered phenol formaldehyde resin. Decay resistance and strength properties were determined before and after simulated weathering. The water resistance of the phenol bonding system was lost in board made from the gas-treated wafers. This white rot fungus Coriolus ve...
E L Schmidt
Mechanical resistance of Pinus radiata CCA treated and face jointed with PVA adhesive
1999 - IRG/WP 99-40140
Due to the increased use of Pinus radiata timber composites (laminated structural members, panels, etc), its low natural durability and the toxicity of phenol-formaldehyde type adhesives, a PVA (polyvinyl acetate) adhesive was evaluated in machined and rough CCA treated and untreated face joint samples under DIN 68602 (EN 204-205) standard for groups of requirement 3 and 4. The results showed that...
M C Rose, L Reyes, P León
Relationship between bond strength and surface characteristics of CCA-treated Douglas-fir
1993 - IRG/WP 93-30008
Chromated-copper-arsenate (CCA) treated Douglas-fir was laminated using a commercial phenol-resorcinol resin. CCA treatment enhanced the water repelleney of wood espeeially in the presence of extractives. However, the shear strength of CCA treated wood was 12% lower in dry condition and 38% lower in wet condition after six cycles of vacuum-pressure test than that of untreated wood. Slight removal ...
K Yamamoto, J N R Ruddick
Durability of surface preserved wood particle boards submitted to atmospherical influence
1995 - IRG/WP 95-40039
The worldwide problem of the continuously growing deficit of high quality natural wood material has caused the attempts of many research workers to find effective composites such as wood particle boards (WPBs) for replacing the massive wood for constructive purposes, depending on where the boards are exploited - in the open or under a shed, they are submitted to various climatic factors such as he...
L Valcheva
Treatment of wood with formaldehyde. Acid catalysis of the reaction between formaldehyde and wood
1980 - IRG/WP 3146
Formaldehyde reacts with the free OH-groups in wood forming cross-linking bonds. The reaction can be brought about without any catalyst but in that case the activation energy is very high and high temperatures and long reaction times are needed. Normally, the reaction is catalysed by different acids. Acid catalysts, however, tend to degrade the cellulose and the wood matrix causing reduction in th...
T Vihavainen, K Piispanen, P Mansikkamäki
Microscopical analysis of formaldehyde-acid modified wood
1981 - IRG/WP 3182
Cross-linking of wood with gaseous formaldehyde improves its hygroscopic and dimensional behaviour, and its resistance against micro-organisms. However, formaldehyde cross-linking reactions take place only in the presence of an acid catalyst, which results in losses in mechanical By optimization of a formaldehyde-sulfur dioxide vapour phase process the reaction conditions were established to limit...
M Stevens, N Parameswaran
Improving the weather resistance of glue-laminated jarrah and karri
1994 - IRG/WP 94-40017
Surface modification and dimensional stabilisation significantly increased the dry and wet shear strength of karri and jarrah lap-shear specimens (laminates) bonded with resorcinol formaldehyde. The combination of surface modification (sanding/sodium hydroxide treatment), and furfurylation produced the highest dry and wet shear strengths. Acetylated laminates had the lowest dry bond strength, but ...
J Balfas, P D Evans
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...
D P Kamdem, J H Hope, A Jermannaud
Generation of hydroxyl radical by the brown-rot fungus, Postia placenta
1988 - IRG/WP 1360
In an electron spin resonance (ESR) survey of various liquid cultures and wood slivers innoculated with the brown-rot fungus, Postia placenta, the spin trap dimethyl-l-pyrroline N-oxide (DMPO) was used to detect the presence of the hydroxyl radical. The ESR spectra for the paramagnetic DMPO- hydroxyl radical adduct was observed in (1) nitrogen-limited, liquid cultures having 1.0% glucose or 0.1% c...
B Illman, D C Meinholtz, T L Highley
Curing conditions for a low formaldehyde etherificated melamine resin
1998 - IRG/WP 98-40108
Waterbased methanol etherificated melamine formaldehyde resins have the potential to increase the resistance of impregnated wood against wood destroying fungi. Previous studies indicated that the resin with the lowest formaldehyde content tested showed the best results regarding fungal resistance, dimensional stability and formaldehyde emissions after curing. In the present paper the influence of ...
D Lukowsky, R-D Peek, A O Rapp
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 aft...
S Fushiki, Y Katuzawa
Biological resistance of wood treated with waterbased resins and drying oils in a mini-block test
1998 - IRG/WP 98-40107
In recent years it was found that the resistance of wood against fungal degradation could be increased by impregnation with an etherificated melamine formaldehyde resin. Using this resin as a reference, a waterbased fatty acid modificated alkyd-resin and two drying-oils were assessed for their biological performance in a mini-block laboratory test. Although drying-oils, like linseed-oil, are often...
M Sailer, A O Rapp, R-D Peek