EFECTO DE UN ENVEJECIMIENTO ACELERADO MEDIANTE RAYOS UV EN LA PROPAGACIóN SUPERFICIAL DE GRIETAS DE DEBOBINADO EN TABLEROS CONTRACHAPADOS DE Eucalyptus nitens

the objective of this study was to evaluate the effect of accelerated aging with uv rays and controlled environmental conditions in lathe check propagation and surface cracking, simulating the conditions of outside service of plywood made with veneers from three heights of logs families segregated of eucalyptus nitens and under conditions of controlled peeling process. to perform the test using an accelerated aging chamber uv (ultraviolet rays) can reproduce the spectrum of radiation emitted by the sun under controlled climatic conditions of relative humidity, condensation and temperature according to astm g154-06. by image analysis assessed the level of surface cracking in the area percentage of the specimens aged in addition to the width of cracks on the plywood surface. image analysis of the aging of the specimen area showed that the crack width and crack area decreases with respect to the height of the log, showing significant differences in cracking between segregated families of eucalyptus nitens. besides lathe checks in the veneers spread to the surface, these being responsible for the cracking in the plywood surface. based on the results of the study, uv-accelerated aging is a good indicator for evaluating the late check propagation and surface cracking in samples exposed to the exterior plywood.