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In this paper, the impacts of heartwood and sapwood usage on the physical, mechanical, and surface properties and formaldehyde emission of particleboard are investigated. European Larch (Larix decidua) trees are chosen as a raw material. The logs are divided into three segments: sapwood, heartwood and total wood. The highest amounts of cellulose (51,54%), and hemicelluloses (22,24%) in the sapwood, followed by total wood, and the heartwood, respectively. However, the highest amount of lignin (30,54%) was found in the heartwood. The highest extractives values are obtained from heartwood, followed by total wood, and the sapwood, respectively. While the lowest pH value (3,03) is found in heartwood, the sapwood samples provide the highest values (4,95). The highest ash (0,49%) content and amount of condensed tannin (13,89%) are extracted from heartwood, followed by total wood, and sapwood, respectively. The test panels manufactured from sapwood have the smoothest surface (7,49 μm (Ra), 48,86 μm (Ry), and 35,12 μm (Rz)) and the lowest contact angles (67,8°), while the roughest surface (14,20 μm (Ra), 68,05 μm (Ry), and 50,02 μm (Rz)) and highest contact angle (96,9°) are obtained from the panels of heartwood. The thickness swelling (19,88%) and formaldehyde emission (7,28%) values of the panels manufactured from heartwood are significantly lower than the panels manufactured from the total wood and sapwood. The highest modulus of rupture (MOR), modulus of elasticity (MOE), and internal bond (IB) values are observed on sapwood, respectively, 15,60 MPa (MOR), 2201 MPa (MOE), and 0,523 MPa (IB). These mechanical strength values (MOR, MOE, and IB) are followed by total wood, and the heartwood, respectively. Surface smoothness and wettability of the particleboards manufactured from sapwood are better than those of total wood and heartwood. [ABSTRACT FROM AUTHOR]

In this study, the effect of residue types (soundwood, branchwood and bark) on the quality properties of particleboards made from the tree of heaven (Ailanthus altissima (Mill.) Swingle) was investigated. For this purpose, the soundwood, branchwood and bark mixed at different ratios were used in the production of particleboards. Modulus of rupture (MOR), modulus of elasticity (MOE), internal bond strength (IB), thickness swelling (TS) and formaldehyde emission (FE) of the specimens were then tested. The chemical and anatomical properties of the residue types were also determined. Residue type was found to have an impact on the properties of particleboards. The addition of bark and branchwood improved the thickness swelling (2 h immersion) and formaldehyde emission. However, use of branchwood negatively affected the thickness swelling for 24 h immersion. Based on the findings of this study, it can be concluded that different parts of Ailanthus altissima (Mill.) Swingle can be used to manufacture particleboard panels. The branchwood and bark contents significantly affected the quality properties of the manufactured particleboards. The chemical and anatomical properties of the branchwood and bark were also found to be parameters influencing the quality properties of the particleboards. The results indicate that the contents of added bark and branchwood should not exceed 10% and 20% respectively. [ABSTRACT FROM AUTHOR]

Textile (cotton) dust, which is harmful to humans and the environment, is one of the largest wastes in the textile industry. The aim of this study was to investigate the potential use of this waste in high value-added materials. Physical and mechanical properties and formaldehyde emissions of the three-layered particleboards with textile (cotton) dust in the middle layer were investigated in this study. A phenol formaldehyde resin was used as the binder in particleboard production. Four different amounts of textile dust (10%, 20%, 30%, and 40%) based on the oven-dried weight of the wood were obtained from a commercial textile manufacturer as industrial waste. The density, thickness swelling, modulus of rupture, modulus of elasticity, internal bond, and formaldehyde emissions of the produced panels were determined. The physical and mechanical properties and formaldehyde emissions of the particleboards were negatively affected, which decreased with the addition of a high amount of textile powder. At low rates, the use of textile dust in the middle layer did not significantly decrease the particleboard properties. Textile dust can be a partial solution for the raw material demand of the wood-based panel industry. [ABSTRACT FROM AUTHOR]

In the present study, the impact of raw material grown region on the physical, mechanical, surface properties and formaldehyde emission of the particleboard was investigated. Ailanthus altissima wood grown in Trabzon had longer fiber length and thicker fiber and trachea cell wall than those of the wood grown in Artvin. The highest amounts of lignin, ash, condensed tannin and solubility values were found in wood grown in Artvin. Ailanthus altissima wood grown in Trabzon had higher amounts of cellulose and hemicellulose than those of the wood grown in Artvin. Particleboards made from wood grown in Artvin had worse surface quality and mechanical strength properties than those of panels made from wood grown in Trabzon. On the other hand, the results showed that particleboards produced from wood grown in Artvin had lower thickness swelling and formaldehyde emision values than those of the panels produced from wood grown in Trabzon. [ABSTRACT FROM AUTHOR]

Highlights: [•] Hardner type, urea usage, and conditioning period of particleboard were investigated. [•] Best properties were obtained from panels manufactured with ammonium chloride. [•] The urea usage positively affected the formaldehyde emission. [•] Increasing conditioning period of panels resulted in better quality properties. [Copyright &y& Elsevier]

The objective of this study was to determine the effect of mimosa bark usage on the formaldehyde emission, physical and mechanical properties of particleboard. Fifteen panels from black locust (Robinia pseudoacacia L.) wood containing mimosa bark in a core layer at different ratios were manufactured. Three boards without bark addition were produced as control boards. Formaldehyde emission, modulus of rupture, modulus of elasticity, internal bond strength and thickness swelling of the specimens were tested. It was found that panels made from black locust wood had the highest mechanical properties while panels containing mimosa bark had the lowest. Bark usage significantly improved (decreased) the formaldehyde emission and thickness swelling of particleboard. Based on the findings of this study, it appears that mimosa bark can be used in the manufacture of particleboard panels. Bark content was found to be a raw material parameter influencing the properties of the panels. [ABSTRACT FROM AUTHOR]

In this study, the effects of lamination technique on some properties of particleboard were investigated. The particleboard surfaces were coated with melamine-impregnated papers, veneers and continuous press laminates. The symmetrical and asymmetrical lamination techniques were used for the coating of particleboard surfaces. Specific gravity, bending strength, modulus of elasticity, swelling in thickness, formaldehyde emission and thermal conductivity of the particleboards were determined. Surface coating materials increased the mechanical properties and thermal conductivity, decreased the thickness swelling and formaldehyde emission of particleboard, significantly. It was statistically proved that surface coating type and lamination technique affected the technological properties of particleboard, statistically. [Copyright &y& Elsevier]

In this study, influence of impregnating wood particles with mimosa bark extract on the some properties of particleboard was investigated. Properties evaluated were modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB), thickness swelling (TS), and formaldehyde emission (FE). The results showed that particleboards made from particles impregnated with mimosa bark extract had significantly lower mechanical, physical and formaldehyde emission values than those of the boards made from unimpregnated particles. Brushing of mimosa bark extract to the surfaces and edges of the particleboards did not affect the mechanical properties, statistically. However, this application caused a significant improvement in the thickness swelling and formaldehyde emission. [Copyright &y& Elsevier]

The main objective of this study was to investigate the effect of paraffin application technique on the quality properties of particleboard. The paraffin was applied to the wood particles in three different techniques: (1) before resination, (2) after resination, and (3) with resin. The modulus of rupture, modulus of elasticity, internal bond strength, thickness swelling, surface roughness parameters, contact angle, and formaldehyde emission of the boards were determined. Statistical analysis showed that paraffin application technique had a significant influence on all properties of particleboards. The boards made using technique (1) had the highest mechanical properties and lowest surface roughness, formaldehyde emission and contact angle values. The worst properties were obtained from the board made using technique (2).