J. For. Sci., 2005, 51(2):76-94 | DOI: 10.17221/4546-JFS

Assessing the bending strength and modulus of elasticity in bending of exterior foiled plywoods in relation to their construction

J. Hrázský, P. Král
Faculty of Forestry and Wood Technology, Mendel University of Agriculture and Forestry Brno, Brno, Czech Republic

The paper summarizes results of an institutional research aimed at assessing the bending strength and modulus of elasticity in bending of exterior foiled combined and all-beech plywoods in relation to their construction. A relationship was studied of the plywood construction and selected physical and mechanical properties. In studied sheets, moisture, density, bending strength and modulus of elasticity were analysed along and across the grain of the upper veneer. All measurements were carried out in water-resistant plywoods with surface treatment with a phenolformaldehyde foil 8, 10, 12 and 15 mm thick in combined plywoods and 10, 12, 15 and 18 mm thick in all-beech plywoods. The construction of plywoods significantly influences their quality that is determined particularly by the bending strength and modulus of elasticity. Using regression analysis relationships were demonstrated particularly that with the increasing moisture content of plywoods the bending strength decreased and with the increasing density the bending strength and modulus of elasticity increased. The same trend was also proved in connection with the increasing number of veneers of plywood sheets. Using correlation analysis, combinations of interrelationships of the given properties were statistically tested.

Keywords: plywood; density; surface density; moisture; thickness; bending strength; modulus of elasticity in bending; veneer; statistical analysis

Published: February 28, 2005  Show citation

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Hrázský J, Král P. Assessing the bending strength and modulus of elasticity in bending of exterior foiled plywoods in relation to their construction. J. For. Sci. 2005;51(2):76-94. doi: 10.17221/4546-JFS.
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References

  1. BALDWIN R.F., 1973. Plywood Manufacturing Practices. San Francisco, Miller Freeman Publications: 141.
  2. MATOVIČ A., 1993. Fyzikální a mechanické vlastnosti dřeva a materiálů na bázi dřeva. Brno, MZLU: 212.
  3. POŽGAJ A. et al., 1993. Štruktúra a vlastnosti dreva. Bratislava, Príroda: 486.
  4. ŠTELLER Š., 1967. Príspevok k stanoveniu niektorých pevnostných vlastností preglejok výpočtom. Bratislava, ŠDVÚ, Drevársky výskum, 1: 29-38.
  5. ŠTELLER Š., 1978. Vplyv vlhkosti na pevnosť v ohybe a modul pružnosti v ohybe celobukových vodovzdorných preglejok. Bratislava, ŠDVÚ, Drevársky výskum, 4: 255-266.
  6. KOŽELOUH B., 1998. Dřevěné konstrukce podle Eurokódu 5. Zlín, KODR: 248.
  7. ČSN EN 310 Desky ze dřeva. Stanovení modulu pružnosti v ohybu a pevnosti v ohybu. Český normalizační institut, 1995: 8.
  8. ČSN EN 322 Desky ze dřeva. Zjišťování vlhkosti. Český normalizační institut, 1993: 8.
  9. ČSN EN 323 Desky ze dřeva. Zjišťování hustoty. Český normalizační institut, 1994: 8.
  10. ČSN EN 325 Stanovení rozměrů zkušebních těles. Český normalizační institut, 1995: 8.
  11. ČSN EN 326-1 Dřevní materiály. Odběr vzorků, řezání a dozor. Český normalizační institut, 1997: 12.

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