Cihat Tascioglu

Incorporation of hazelnut shell and husk in MDF production

Hazelnut shell and husk (Coryllus arellana L.) is an abundant agricultural residue in Turkey and investigating the possibilities of utilizing husk and shell in panel production might help to overcome the raw material shortage that the panel industry is facing. The aim of this work was to investigate the possibilities of utilizing hazelnut shell and husk in medium density fiberboard (MDF) production. To produce general purpose fiberboards, fiber-husk and fiber-shell mixtures at various percentages were examined in this study. The results indicated that panels could be produced utilizing hazelnut husk up to 20% addition without falling below the properties required in the standards. Shell addition was restricted up to 10%, because higher addition levels diminished the elastic modulus and internal bond strength below the acceptable level.

Rate and extent of adsorption of ACQ preservative components in wood

Abstract The adsorption of copper, [as Cu(II)], monoethanolamine (MEA) and didecyldimethyl ammonium chloride (DDAC) components of CuMEA and alkaline copper quaternary (ACQ) solutions impregnated into wood was followed by measuring the changes in solution concentrations in the wood over time. The rate and extent of copper and MEA adsorption were highly dependent on the solution strength and the conditioning temperature. Both copper and MEA were adsorbed by the wood structure with a rapid initial reaction, with higher relative amounts sorbed from lower concentration solutions. This was followed by a slower adsorption that still had not equilibrated after 7 weeks at 22°C. Generally, the adsorption pattern was similar for copper and MEA, suggesting that they were adsorbed as a copper MEA complex, with an MEA/copper molar ratio close to the theoretical maximum of 4. At a higher conditioning temperature of 50°C the reaction time was greatly reduced, with the adsorption after 1 week higher than after 7 weeks at 22°C, suggesting faster and more complete reaction at higher temperatures. DDAC was adsorbed more quickly and to a higher degree than Cu(II) for all treatment solutions and should be preferentially removed from such solutions, especially if empty-cell treatments are used. There appeared to be higher Cu adsorption from the higher concentration solutions of CuMEA than from corresponding ACQ solutions, likely due to DDAC competition with copper for the same reaction sites.

Biological performance of copper azole-treated wood and wood-based composites.

Abstract Vacuum-impregnation with copper azole was applied as a post-treatment to five commercially available wood-based composites with thicknesses of approximately 12 mm, such as softwood plywood (SWP), hardwood plywood (HWP), medium density fiberboard (MDF), oriented strand board (OSB), and particleboard (PB). Untreated and treated composites were tested for their resistance to decay fungi (brown rot fungus Fomitopsis palustris and white rot fungus Trametes versicolor) and the subterranean termite Coptotermes formosanus by Japanese standardized laboratory test methods. Untreated MDF was highly resistant to both biological attacks and seemed to require no preservative treatment under less hazardous conditions, i.e., under protected and above-ground applications, with possible occasional wetting. PB was ranked second, and needed further protection only against C. formosanus. Copper azole did not adequately protect SWP from F. palustris and termite. OSB was not protected either against F. palustris and T. versicolor even at a concentration level of 1 kg copper azole per m3 in contrary to blocks of Cryptomeria japonica sapwood, which was protected at these concentration levels. The biological resistance of HWP was reasonably improved by copper azole. The performance of wood-based composites treated with copper azole, which was inferior to the biological resistance of treated C. japonica sapwood blocks, might depend on the thickness or layer profile, density as a result of porosity, uneven distribution of the preservative in the composites, and the susceptibility of the component raw materials.

Effects of fixation temperature and environment on copper speciation in ACQ treated red pine

Abstract Red pine (Pinus resinosa Ait.) sapwood samples treated with alkaline (amine) copper quaternary (ACQ) were conditioned at different temperatures and under wet or dry conditions to evaluate the stability of copper (Cu) to leaching and conversion of divalent copper (Cu-II) to monovalent copper (Cu-I). Significant Cu-II was reduced to Cu-I during post-treatment stabilization, especially at elevated temperatures (105°C and 120°C). The percent conversion to Cu-I was higher at lower retentions; in some cases, at low retentions and high fixation temperatures, all of the cupric Cu was reduced to Cu-I, raising the possibility of reduced activity of Cu as a biocide when high temperature conditions are used to fix ACQ treated wood. However, exposure of wood to a leaching procedure (rewetting, re-drying) generally resulted in a significant component of the Cu-I in wood being oxidized back to Cu-II. Steaming of weathered ACQ treated wood at 120°C also converted significant amounts of Cu-II to Cu-I.

Determination of biological performance, dimensional stability, mechanical and thermal properties of wood–plastic composites produced from recycled chromated copper arsenate-treated wood:

The aim of this study was to investigate the dimensional stability, mechanical and biological performance and thermal degradation of wood–plastic composites made from high-density polyethylene and recycled wood treated with chromated copper arsenate (CCA), a commonly used wood preservative chemical. Virgin pine wood samples were also prepared with and without a coupling agent and used as the control group. Samples of CCA-treated Scots pine (Pinus sylvestris L.) with varying wood content were produced by adding different ratios of the coupling agent. The recycled CCA-treated wood-filled composites exhibited better flexural and tensile strength properties and dimensional stability than the control group, whilst their impact strength was less. Biological test values showed improved durability against termites and fungus with the recycled CCA-treated wood-filled composites. In addition, the leaching of heavy metals was significantly diminished when the coupling agent was utilized at a level of 5% (w/w), thus presenting a much lower impact on the environment.

Mechanical, thermal, morphological properties and decay resistance of filled hazelnut husk polymer composites

Four different formulations of natural fiber-polymer composites were fabricated from mixtures of hazelnut (Corylus avellana) husk flour (HHF), polypropylene (PP) and high density polyethylene (HDPE). Variables examined included polymer and coupling agent types. All formulations were compression molded in a hot press for 3 minutes at 175 0C. The resulted specimens were tested for mechanical properties according to ASTM D-790 and ASTM D-638. In addition, scanning electron microscopy (SEM), thermogravimetry (TG) and Differential Scanning Calorimetry (DSC) analysis were performed to characterize rheological properties of the fabricated composite. Furthermore, decay tests were performed to determine degradation of hazelnut husk polymer matrices. Hazelnut husk polymer composites had high mechanical properties for the tested formulations. The thermal studies showed that incorporation of hazelnut husk into the polymer matrices used did not adversely affect the composite. The HDPE+50% wood + 3% MAPE (HHF2) formulation showed the highest natural durability with only 3,47% and 4,60% mass losses against Trametes versicolor and Postia plecenta, respectively, while Scots pine solid controls experienced around 32% mass loss under the same exposure condition.

Potential utilization of sodium fluoride (NaF) as a biocide in particleboard production

The feasibility of sodium fluoride (NaF) incorporation as a biocide in the manufacture of particleboard was examined. Laboratory-scale particleboards prepared from untreated wood particles were incorporated with NaF powder at target retentions of 1, 1.5 and 3% of the total particle weight. An in-line treatment method was used to introduce the biocide during the blending stage just before adhesive application. Standard static bending and water resistance (water absorption and thickness swelling) tests indicated that embedding of the powder biocide up to the 3% level did not cause any detrimental effects on mechanical and physical properties. The laboratory decay and termite resistance tests showed that even the lower retention levels of 1 and 1.5% NaF were enough to suppress fungal and termite activity and significantly reduce the mass loss and consumption rate values of the specimens when compared to the untreated controls. Spectrophotometric analysis of leachate waters and the mass losses of the leached specimens revealed the tendency of the NaF to be depleted from the composite specimens. Therefore, the tested biocide was found to be appropriate for interior or protected above-ground outdoor exposure conditions.

Antitermitic effects of three wood stain treatments

Potential antitermitic properties of some common wood stains were tested against Coptotermes formosanus. Four different wood species treated with 3 different stain chemicals at the 0,1 kg/m2 retention level were exposed to no-choice termite feeding test in laboratory conditions. Mean mass loses, mortality rates and consumption rates were calculated based on weight changes before and after the test. While the hardwood species (beech (Fagus orientalis) and chestnut (Castanea sativa) tested were unaffected by the treatments, the softwood species tested showed drastically reduced mass losses with some stain treatments. Scots pine (Pinus sylvestris) and spruce (Picea orientalis) sapwood exhibited significant reductions in mass losses when treated with the chemical stain.

LARVICIDAL ACTIVITIES OF SOME BARK AND WOOD EXTRACTS AGAINST WOOD-DAMAGING INSECTS

This study investigates the larvicidal activities of plant extracts and tannins against wood-damaging insects. Scots pine (Pinus sylvestris), beech (Fagus orientalis), and poplar wood (Populus tremula) were subjected to larvae of Spondylis buprestoides (Coleoptera: Cerambycidae) by impregnating them with mimosa (Acacia mollissima), quebracho (Schinopsis lorentzii) and redpine bark (Pinus brutia) extracts. At the end of the 6-month experiment, the numbers of dead and live larvae as well as the mean mass losses of woods were determined. In terms of wood species, the lowest larva resistance was observed in Scots pine wood, while the highest larva resistance was achieved by beech wood. The lowest mass losses and the highest dead termite rates in all tree species were observed when the concentration of mimosa and quebracho extracts was 12%. On the other hand, the pine bark extract showed a lower larvicide effect than the other two extracts.

Hizmet Ömrünü Doldurmuş Emprenyeli Ağaç Malzemenin Geri Dönüşüm Yöntemleri Üzerine Genel Bir Değerlendirme

Wood presevatives such as creosote, pentaclorophenol (PCP) and chromated copper arsenate (CCA) have been widely used over the years in order to extend wood products’ service life. CCA was known as most widely used wood preservative chemical in residendial and commercial applications world wide until 2004 volanteered phase out of the chemical from residential use bye the major manufacturers. Over the years CCA treated wood acuumulated in service reaching millions of cubic meters. But there is growing concern about the environmental impacts and increasing difficulty in disposing of treated wood products in many countries. Since disposal of CCA treated wood material poses greater problems than the other treated wood products due to heavy and toxic metal componets of CCA such as chromium and arsenic Traditional disposal methods like landfillig or incineration, both have negative environmental consequences. For that reason the increasing volume of CCA-treated wood products coming out of service requires alternative disposal methods and recycling techniques never tried before. The main purpose of this study, except for traditional methods like landfilling and incineration, is to evaluate the current alternative disposal and recycling methods for CCA treated wood removed from service.