Resistencias Mecánicas de Tableros de Partículas Producidos con Mezclas de Especies Chilenas

Abstract

Bending strength, MOR, and tensile strength, IB, were determinate d on particleboards. The panels were mad e up with the Chilean woods: Saxegothea conspicua, Podocarpus saligna, Nothofagus dombeyi, Drimys winteri, Laurelia philippiana, Weinmania trichosperma, Eucriphia cordifolia, a few Myrtus an d mixture s of all these.
Panels density varied between 40 0 kg/m3 an d 80 0 kg/m3.
Other processing parameters were :
Board thickness: 11mm ; Adhesive contents: 7,9 percent urea—resin solids, based on ovendr y weight of particles; Proportion of face an d core layers: 30 percent face layers an d 70 percent core layer.
T h e recorded strengths of each species were weighted with the species participation on the particle mixtures, and a "weighte d strength " was calculated. Comparisons of weighted strength and the actua l strength of the particle mixture were made.
The mean differences, between actual a nd weighted stregth, were 0,062 N/mm 2 for interna l bon d and 0,562 N/mm 2 for bending strength. The difference, as a percentage of the weighted strehgth, was 4% for bending strength an d 10,3% for internal bond.
The statiscal analysis shows no significant differences between actua l and weighted strenght. Th e "F " value for tensile strength was 0,2021 with a probability of 0,6545.
The differencess between the empirically determinate d bending strenght and their actual values, were smaller tha n thos e o f the interna l bon d tests. The "F " value for bending strength was 0,050 8 a n d the probability value was 0,8224.