What do the quality grades of rotary-cut veneers indicate about their internal structure in correlation to their mechanical properties?

Research output: Contribution to journalResearch articleContributedpeer-review

Abstract

The quality grading of rotary-cut veneers, as defined by various standards, considers the quality features and surface appearance of plywood or molded plywood. This grading primarily focuses on visual surface characteristics, such as knots, cracks, and discoloration. However, the correlation between these quality grades and the internal structural features, such as fiber deviations, lathe check depth, and frequency, and their impact on mechanical properties remains unexplored. This study investigates the relationship between the quality grades (A, B, and C) of Fagus sylvatica (european beech veneers) and their mechanical performance, as represented by the modulus of elasticity and the tensile strength. Structural features were quantitatively analyzed. Tensile tests revealed that veneers of quality grade C exhibited significantly lower modulus of elasticity (10737 MPa) and tensile strength (78,2 MPa) than grades A and B. Grade B veneers showed comparable modulus of elasticity values of 13500 - 13800 MPa but differing tensile strengths of 88,3 MPa for grade A and 116,8 MPa for grade B on average. Structural analysis indicated that grade C veneers exhibited the highest fiber deviations in the thickness direction (up to 20 %) and the highest lathe check depths (46 %), suggesting a qualitative alignment between grading and structural integrity. However, the structural differences between grades A and B did not consistently reflect their mechanical performance.

Details

Original languageEnglish
JournalMaderas: Ciencia y Tecnologia
Volume28
Early online date29 Jul 2026
Publication statusE-pub ahead of print - 29 Jul 2026
Peer-reviewedYes

Keywords

Keywords

  • Fagus sylvatica, mechanical properties, rotary-cut veneer, structural features, tensile strength, veneer grading