Efeito da tratamento térmico na cor das madeiras de hymenaea spp. E ficus sp.

Abstract

The process of thermall modification is a viable option in improving wood properties, promoting greater biological resistance, greater dimensional stability and color change, giving greater added value to the product, besides being a method that does not cause damage to the environment, since the use of chemical agents does not occur. This study aimed to evaluate the effect of different thermal modification temperatures on the colorimetric properties of Hymenaea spp. and Ficus sp. The material used in this study came from sawmills in the municipality of Itacoatiara - AM, where samples with about 12 x 10 x 5 cm were produced (length, width and thickness, respectively. The identification of the species was performed from macroscopic anatomical analyses. The heat treatment tests were carried out in an oven with temperatures of 140°, 160° and 180°C for a period of two and a half hours, aiming at characterizing mass loss and colorimetry. Alcohol extraction was extracted from the reduction of the sawdust samples. The influence of temperatures on wood color was analyzed by Munsell's color table. The results showed that there was mass loss for all treated woods and darkening in the samples as the temperature increased. The temperature of 180 °C was the one that promoted the highest darkening of the respective species. In the indices of extractive contents, there was a variation between the genus Hymenaea spp. and Hymenaea intermedia Ducke presented the highest value (18.21%). The main differences in the macroscopic anatomical characteristics of the genus Hymenaea spp. are highlighted: types of parenchymas, vessels, frequency of rays, as well as the height and width of the rays. Therefore, the heat treatment of the woods promoted the darkening of the color in all species, and these changes add value due to the homogenization of the parts and expand the use in the timber sector.