Avaliação da modificação térmica na qualidade da madeira laminada colada de caxinguba (ficus sp.)

Abstract

The objective of this study was to evaluate the effect of temperature on the physical-mechanical characteristics of glued laminate produced with thermally modified caxinguba wood. The wood came from donations from a sawmill located on the banks of the Amazon River, in the municipality of Itacoatiara (AM). The wood was transformed into samples and slats. The samples were intended for macroscopic identification, characterization of moisture content, basic density and apparent density. The slats were cut with dimensions of 37,0 x 0,4 x 4,0 cm (length x thickness x width) to produce the glued laminate. The material was thermally modified in an oven with forced air circulation. The treatments consisted of the application of the following temperatures: 120ºC, 140ºC and 160 ºC, in addition to the control treatment (100 ºC). The moisture content of the treated slides and weight loss of each treatment were quantified. For bonding the glued laminate, four wood veneers oriented parallel to the fibers were used. Resin based on urea-formaldehyde (UF) with a grammage of 300 g/m2 (single line) was used. Physical (moisture content, basic and apparent density and shrinkage) and mechanical (static bending and parallel compression) tests were carried out. The physical properties showed that the moisture content of GLCT treated at a temperature of 160 ºC showed a lower value. The basic density was not influenced by heat treatment. Basic density and shrinkage were not influenced by thermal modification. For the mechanical properties it was observed that the thermal modification of the wood significantly improved the valuesof compression and modulus of rupture, while the modulus of elasticity showed a trend of improvement with the treatment, in relation to the control. It is recommended to use glued laminate for non-structural elements, such as dividing walls, furniture and tool handles, lining, in addition to assistive technology equipment, such as crutches, canes and walkers.