Evaluation of Eucalyptus dunnii (Maid) wood for plywood manufacturing

Author(s)

Obdulio Pereyra

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 1995-03-10
• Advisor: Ivaldo Pontes Jankowsky

Abstract

The objective of this study was to evaluate the potential of Eucalyptus dunnii (Maid) wood for producing peeled veneer and plywood. Three heating temperatures for the logs (50, 65 and 80°C) and three different horizontal openings for the knife lathe setting (1,7; 1,8 and 1,9 mm) were tested. For the veneer experiment it was used 16 twenty years old trees from the Canoinhas region of the State of Santa Catarina. A completely randomized experimental design with a factorial arrangement was employed. The veneer was produced in the laboratory, and the impact of the main variables of the process (heating temperature and horizontal opening) on the veener quality and yield were evaluated. The results indicate that the best heating temperature is between 65° to 80°C and the best opening between 1,8 and 1,9 mm. It was verified that it is possible to use Eucalyptus dunnii as row material to produce veneer with good quality characteristics. Based on the best results observed at the laboratory level, test of veneer and plywood production at industrial level was conducted using logs got from 12 years old Eucalyptus dunnii trees from the region of San Vicente, provincia of Misiones (Argentina). Physical and Mechanical tests were carried out to caracterize the 16 mm thick plywood produced. The overage values obtined were: specific gravity = 0.771 g/cm3; moisture content = 8.72%; water absortion = 44.09%; swelling = 11.63%; thickness recovery = 2.58%; perpendicular bending = (MOE: 7,266.27 MPa - MOR: 57.96 MPa); paralel bending = (MOE: 8,672.16 MPa - MOR: 65.85 MPa). Compared with the NBS/PS 51-71 standard, the plywood produced can be used for interior. (AU)