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Research on mechanical properties of birch plywood with special veneer lay-up schemes

100%

Lipinskis I., Spulle U.

Drewno. Prace Naukowe. Doniesienia. Komunikaty

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2011

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tom 54

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nr 185

Plywood is a wood-based panel material laminated of veneers where the grain direction is perpendicular in adjacent layers. The use of plywood can be extended if there is a possibility to use special lay-up schemes designed to improve mechanical properties which depend on the grain direction in the outer plies. This report contains results of research whose purpose was to determinate bending strength and modulus of elasticity of birch plywood types with special veneer lay-up schemes and of different width, bending flatwise and edgewise. Two special plywood types, 28 mm thick Spec1 and 30 mm thick Spec3, with different veneer lay-up schemes were selected for bending properties determination tests according to standard EN 789. Specimens were tested when the face veneer direction was parallel and then perpendicular to the specimens’ longer axis. Moisture content and density were determined as well. This report contains the comparison of bending strength properties of special plywood specimen with different width and load direction. It was found that bending strength was significantly higher for narrower special plywood specimens, and bending strength of special plywood loaded edgewise was 4 % lower for Spec1 and 9.5 % lower for Spec3 than for flatwise loaded specimen of the same cross-sectional dimensions.

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Elastic constants of veneer in beech plywood

100%

Wilczynski M.

Folia Forestalia Polonica. Series B - Drzewnictwo

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2011

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tom 42

The paper presents the results of the study concerning elastic properties of beech veneers assembled in plywood panels. There has been derived a complete set of elastic constants for veneers considered as orthotropic bodies. Young’s moduli in the grain direction and in the direction perpendicular to the grain were determined by bending plywood strips with their longitudinal axis parallel and perpendicular to the grain of the face plies. The other elastic moduli of the veneers were calculated through the Young’s modulus in the grain direction, with using the regression functions derived for hardwoods by Bodig and Goodman (1973). The effect of glue lines in plywood on the veneer elastic properties was evaluated.

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Dlaczego sklejka sie paczy?

86%

Borysiuk P., Grobelny T.

Biuletyn Informacyjny Ośrodka Badawczo-Rozwojowego Przemysłu Płyt Drewnopochodnych w Czarnej Wodzie

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2006

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tom 46

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nr 3-4

116-130

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Pora dla sklejki na elastycznosc

86%

W K.

Biuletyn Informacyjny Ośrodka Badawczo-Rozwojowego Przemysłu Płyt Drewnopochodnych w Czarnej Wodzie

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1994

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tom 35

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nr 3

240-241

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Protic ionic liquids as a new hardener-modifier system for melamine-urea-formaldehyde adhesive resins

86%

Jozwiak M., Pernak J., Kot M.

Drewno. Prace Naukowe. Doniesienia. Komunikaty

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2011

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tom 54

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nr 186

This paper presents the results of investigations on the possibility of using protic ionic liquids as a hardener and modifier of melamine-urea-formaldehyde (MUF) adhesive resins. In research dialkylmethylammonium dodecylbenzenesulfonate base protic ionic liquids with varied amounts of carbon in alkyl group were used. The plywood manufactured using protic ionic liquids and MUF resin was characterized by a complete water resistance of glue lines, thus meeting the requirements of EN-314-02 standard.

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