Composite wood products
Mohammad Hamed; Babak Nosrati; Ali Shalbafan; Mohammad Dahmardeh Ghaleno; Saeid Reza Farrokhpayam
Abstract
In recent years, the most important challenge for wood-based compact producers has been an increasing demand for a variety of wood materials, raw material prices, and rising transportation costs. On the other hand, the use of lightweight elements in the manufacture of decoration and furniture has received ...
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In recent years, the most important challenge for wood-based compact producers has been an increasing demand for a variety of wood materials, raw material prices, and rising transportation costs. On the other hand, the use of lightweight elements in the manufacture of decoration and furniture has received much attention. The present study aimed at evaluating the effect of different levels of two variables on the size and amount of expanded polyurethane chips in the production of lightweight composite particle boards. To this end, the size of polyurethane particles at three levels (10, 5, and 15 mm) and their amount at four levels (10, 5, 0, and 15%) were chosen as research variables, and the amount of adhesive consumption, press pressure, board thickness, and final density were considered as fixed factors. The results showed that flexural strength, the flexural modulus of elasticity, internal adhesion, and thickness elongation increased significantly with increasing the size of polyurethane particles in the middle layer of the board, but the effect of size was not significant on the water absorption of the samples. Also, increasing the percentage of polyurethane in the middle layer increased the mechanical properties and improved the physical properties compared to the control sample, and it had the largest effect on the internal adhesion of the samples.
Composite wood products
Hossein Rangavar; Abolfazl Kargarfard; Mohammad Hamedbazzi
Abstract
In this study the effect of adhesive types and coated veneer on the physical and mechanical properties of particleboard were studied. Two types of coating, including natural veneer of beech and artificial veneer of High Paper Lamination (HPL, formica) and three types of adhesive composition including ...
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In this study the effect of adhesive types and coated veneer on the physical and mechanical properties of particleboard were studied. Two types of coating, including natural veneer of beech and artificial veneer of High Paper Lamination (HPL, formica) and three types of adhesive composition including (100 % UF), (15% PVA + 85 % UF) and (25% PVA + 75% UF) were used to stick the veneer on particleboard. Physical and mechanical properties of the boards were evaluated according to the EN and ASTM standards. The results of this study showed that increasing PVA resin mixed with UF adhesive, in natural and artificial veneers covering, improved the physical and mechanical properties of the boards. Also, the results indicate that the beech veneer boards are more adhesive than formica. However, formica coated boards compared with beech veneer boards, showed higher bending strength and higher modulus of elasticity. It is evident that the water absorption and thickness swelling values in formica coating boards were less than the beech veneer. Collectively, for production of wooden furniture such as library shelves and cabinets, formica decorative coatings must be used to improve the bending strength. The formica decorative coatings are high in abrasion resistance and stable in humid environment. To stick formica decorative coatings on particleboards, the recommended mix design is 25% PVA and 75% UF resin.
