Moisture Content and its Influence on the Roughness and Noise Emission during Wood Machining

Abstract

Numerous factors influencing the surface quality of wood after machining, among them we highlight the machining parameters and the properties of the wood. In the analysis of the influence of these factors on machining and in determining the quality measurement systems are used to obtain surface characteristics, these systems are divided into methods of contact and non-contact. The method for mechanical contact performed with the aid of the surface roughness tester is the most valued in the measurement of roughness of wood, however, aiming at a greater agility in these measurements, there is a need to seek alternatives for evaluation of surface quality, and one of these options is to use the forms of indirect measurements of this quality, as for example, the use of noise emission during the machining process. With this, the aim was to analyze the influence of the moisture content of the wood, at different levels, on surface quality of the species Pinus elliottii, determined by the method of mechanical probing move and relate this roughness with the sound emission issued for each class of humidity, during machining. The planning of experiments and statistical analyses were performed with the help of Taguchi method. The specimens were conditioned in greenhouses climatizadoras automatics for obtaining three classes of humidity. Machining tests of wooden pieces were performed on a machining center specific for this type of material. The roughness values were measured by a roughness verifier and the noise emission values were measured by for a measurer sound pressure level. Statistically significant differences were observed, the significance level of 10 %, on roughness and noise emission between the three levels of moisture. It was observed that with the increase in the moisture content occurred an increase of roughness and a reduction in noise emission. Monitoring of surface quality through noise level is an interesting alternative to the method of mechanical contact.

Sanding and Shaping Characteristics of Gmelina arborea Grown in Two Ecological Zones in Ghana

“…Previous studies by Davis [12] as cited in Mitchual et al [15] suggested that best wood machining results could be obtained at 6% moisture content and the poorest at 20% or more moisture content. Pinheiro et al [19] also observed that the surface roughness of wood increases with increasing moisture content. Therefore, the moisture content of the samples for this study could be considered adequate.…”

“…The mean moisture content of the samples just before the test was 14% and 15% for WEFZ and DSDFZ respectively. Reports indicate that samples at lower moisture content have better machining qualities than at higher moisture content [19,8,12], indicating that samples from WEFZ should have performed better than those from DSDFZ but showed otherwise. This could mean that surface quality depends on moisture content to some extent and in this case shaping at 14% or below could generate more machining defects.…”

Optimization of wood machining parameters using artificial neural network in CNC router

“…The effect of MC on surface quality in machining differs by wood species and sections [39][40][41]. Pinheiro et al [42] studied the influence of MC on SR and noise emission during wood planning. They observed that an increase in MC led to an increase in roughness and a decrease in noise emission.…”