Effects of the thickness of rotary-cut veneers on properties of plywood sheets. Part 1. Compressibility of plywood materials

Abstract

The paper summarizes results of the institutional research aimed at the determination of compressibility or values of the reduction of thickness of compressed plywood sheets. Assessing the effect of thickness and thickness tolerances of veneers to a value of compressibility in relation to production parameters was carried out on the collection of plywood whole-beech sheets of the nominal veneer thickness of 1.5 mm. The plywood sheets were manufactured as seven-ply ones and urea-formaldehyde resin DUKOL S was used for their manufacture. Following characteristics were assessed: thickness differences, size of shrinkage, compressibility of veneers. Sheets were pressed using a pressure of 1.5 and 1.7 MPa. Values of changes in the thickness of veneers in pressed veneer sheets and coefficients of compressibility of particular properties were then statistically analyzed. Basic economic evaluation was carried out of the effect of compressibility on the amount of production costs.

Keywords

• plywood
• modulus of elasticity in bending
• bending strength
• veneer
• statistical analysis
• compressibility
• shrinking