This work deals with the influence of specific pressure during press process on radial and tangential penetration urea-formaldehyde (UF) adhesive into poplar, as well shear strength lap joints prepared at these different pressures. An epi-fluorescence microscope was used for measuring when investigating microtome slides (20-µm thick) cut from joint samples. The average depth (dap) size interphase region (I) increased increase 0.5 to 1.0 N/mm2. Further in 1.5 N/mm2 did not produce a...

The urea-formaldehyde (UF) adhesive is still most important system in the production of interior grade particleboards and medium density fibreboards (MDF). However, furniture fitments, incorporating these products, present one sources formaldehyde emission into indoor air. recognition as a substance that presents risk for human health had strong impact on wood-based panels industry, it came under constrains by number national international regulations. Hence, this paper overview standards...

Inert gas atomized prealloyed copper powder containing 2 wt.% Al (average particle size ? 30 ?m) and a mixture consisting of sizes 15 ?m 4 commercial Al2O3 particles 0.75 were milled separately in high-energy planetary ball mill up to 20 h air. Milling was performed order strengthen the matrix by grain refinement particles. air promoted formation finely dispersed nano-sized internal oxidation. On other side, composite powders with micro-sized obtained mechanical alloying. Following milling,...

Differential scanning calorimetry (DSC) was used to evaluate the curing kinetics of two commercial urea-formaldehyde (UF) adhesives having different formaldehyde urea (F/U) ratio 1.112 (UF1) and 1.086 (UF2). DSC measurements were done in dynamic regime with heating rates 5, 10, 15 20?C?min-1 order determine activation energy for each adhesive. Obtained data analyzed using isoconversional methods application Ozawa-Flynn-Wall Kissinger-Akahira-Sunose kinetic models. In addition, catalyst...

This paper describes some results obtained in an investigation of urea-formaldehyde (UF) resins different degrees polymerisation by Matrix-Assisted Laser Desorption/Ionisation Time-of-Flight (MALDITOF) mass spectrometry (MS). MALDI-TOF MS proved to be appropriate technique for analyzing these types polymers, bearing mind that the analysis correspond with previous physical and chemical measurements. enables a relatively swift determination degree through monitoring key changes structure...

This research was based on presumption that the changes in size and shape of wood particles are expected to have certain impact particleboard quality general. Since conventional (PB) oriented strand board (OSB) were built quite diverse particles, they present interesting specimens comparison tests. In this work, influence type edge screw holding performance OSB investigated. Those tests obtained with diameters 4.0 mm, 4.5 mm 5 mm. Depth embedment 30 for all pilot-hole diameter kept range...

<title>Abstract</title> This study explores the potential of using condensate generated during beech wood steaming (BSC) as an eco-friendly additive in urea-formaldehyde (UF) adhesives for wood-based panel (WBP) production. The research aimed to assess hardening behavior pure commercial UF resin and with added (UFC), investigating catalytic effect BSC on characteristics adhesives. Changes chemical structure after curing process were observed Fourier transform infrared spectroscopy (FTIR)....

Stress state effect on dynamic strain aging (DSA) and the related surface appearance was analyzed in uniaxial biaxial room temperature stretching of AlMg7 alloy sheet. In tension serrated yielding found pertinent at entire range for tested material. Stretcher markings, usually noted as A (flamboyant ) type, formed during yield point elongation, while type B (parallel bands) appeared higher strains, due to Portevin Le Chatelier effect. Stretching sheet material over an hemispherical punch....

The acidity of wood has an important role in many areas applications. Hence, this paper presents a study on the beech, fir and poplar, as representatives most industrially utilized species Serbia. contents both soluble insoluble acids were determined through extraction methods with cold distilled water sodium acetate solution, respectively, followed by titration hydroxide solution. strongly differs among three used research. amount was highest fir, almost twice much than about 68 % higher...

Particles of beech wood were treated with hot water at the temperature 150 oC, during 60 min, prior to pelleting process. The applied pretreatment affected chemical composition and heating value particles. Two groups pellets, designated as PT 10 20, produced from particles, moisture content particles being 10.5 20.5 %, respectively. Pellets nontreated (PNT) served controls assess effects on pellet properties. Both, pretreatment, particle content, properties obtained pellets. ad 20 pellets...

The influence of Narrow Leaved Ash (Fraxinus angustifolia Vahl. ssp. Pannonica Soo & Simon) pre-treatments on the curing behavior urea-formaldehyde (UF) adhesive was studied. Differential scanning calorimetry (DSC) used to monitor reaction UF mixed with non-treated wood flour (control series) and leaved obtained after different particles. Three were applied, one sodium carbonate solution (0.03 g/g dry wood), acetic acid (0.06 wood) distilled water. systems showed no apparent differences in...

There is an increased research interest in methods for transparent wood production and its use. Wood transparency could be achieved by delignification followed impregnation process with polymers having proper optical properties. However, processes are mainly time consuming not environmentally friendly. The possibility of treating mahogany (Swietenia macrophylla King) 20% hydrogen peroxide 70, 100, 135, 170 min at 103 °C presented this research. According to the treatment duration, lignin...

The goal of this paper is to analyze the chemical composition untreated and treated wooden chips from native narrow-leaved ash (Fraxinus angustifolia Vahl. ssp. Pannonica Soó &amp; Simon). In order determine effect pretreatment with liquid hot water (LHW) on changes in composition, content moisture, cellulose, lignin, minerals (ash), extractives soluble water, organic solvents, for was determined. This done accordance TAPPI ASTM standard methods. properties chips, 30 min 60 at a temperature...

Urea-formaldehyde (UF) glue resins were the most important type of adhesives in wood industry last 60 years, especially for production based panels. More convenient spray dried UF powders went into use two decades. Small and medium private processing plants Serbia prefer to such powder adhesives, since they are more small capacity production. There is no resin so necessary quantities imported from abroad including producers Asia. However, their characteristics variable, dependent on...

&amp;lt;p&amp;gt;In this review paper, metabolism of most used inhaled halogenated anesthetics (halothane, enflurane, isoflurane, desulfurane and sevoflurane) is shown Only part the metabolized, while remainder eliminated unchanged. They are metabolized by mixed function oxidases (reductive or oxidative pathways).&amp;amp;nbsp;&amp;lt;/p&amp;gt;

In regard to its hygroscopic properties, particleboard is dimensionally unstable material when exposed water or in the atmosphere of high level humidity. Since today several different standardized methods for determination thickness swelling exist, aim this study was focused on comparison testing methods. aim, three soaking and were compared, two which defined by national standard SRPS D.C8.104 one European EN 317. The results both properties have shown no significant difference between...

In the aim to achieve fire-resistant plywood of different wood species, in this study, veneers have been impregnated with solutions chosen fire retardants, which are diammonium phosphate, monoammonium sodium acetate, water glass, tetraborate and boric acid. To determine preliminary level retardancy achieved before manufacturing finished plywood, thermogravimetric (TG) derivative (DTG) methods used. TG DTG analyses treated untreated wood, as well retardants alone, were performed on a...