Influência da densidade da madeira processada no nível de ruído gerado

Abstract

The relationship between occupational hygiene and the mechanical processing of wood is of great importance for improving the health and comfort of workers and also for the production and economy of the process. In the wood mechanic processing, the emission of high levels of noise is observed. The objective of this work was to know and evaluate the effect of the variation of wood density on the noise generated from its mechanical processing. With this, it is proposed to provide better conditions of work for the operators of this sector. In the woodworking laboratory, continuous and intermittent noise levels were collected every five seconds using the sound pressure level meter (decibelimeter), according to the procedures defined by NHO 01, during the planing of different density classes. The Shapiro-Wilk test, at 1% significance, was performed to verify the normality of the noise level data. Subsequently, the Wilcoxon paired test was chosen, at 1% significance. The machine presented noise levels above that allowed by Brazilian legislation for all wood density classes. The highest noise level (112 dB (A)) was found in high density wood. The lowest value (79dB (A)) was found in all density classes. There was a significant difference in the study of the noise level caused by the three wood density classes, by the Wilcoxon test paired at 1% of significance. The different wood density classes present a significant statistical difference in the noise levels, continuous or intermittent, generated during the planing of the same. The density of the wood was directly proportional to the mean level of noise and noise levels. The HDI (Hearing deterioration index) found was 62 for the low density woods, while the mean and the high showed the same falsehood of 64. This index can be used as a preventive measure to detect, in a fast way, the probability of environments with occurrence of noise-induced hearing loss.