Several previous studies have investigated the effects of heat treatment on the chemical composition, along with the physical and mechanical properties, of wood from various species. However, the effects of these property changes upon the machining properties and surface quality of machined wood have been studied much less. The main goal of this work was to investigate the comparative cutting power consumption during milling and the resulting surface roughness of heat-treated and untreated beech wood (Fagus sylvatica L.). Several cutting regimes were tested by combining different values of rotation speed, feed speed, and cutting depth. The cutting power and the processing roughness were assessed and compared. The results clearly showed that the cutting power involved in the milling of heat-treated beech wood was up to 50% lower than that of untreated wood, but the processing roughness was slightly higher.

No abstract

No abstract

Thermally treating wood improves its dimensional stability and durability. The chemical changes brought about by a heat treatment also affect the mechanical properties of wood. Consequently, a heat treatment also influences how a wood surface responds to machining. This study examined the impact of heat treatments at 200 C between 1 h and 6 h on the subsequent surface quality of planed beech wood (Fagus sylvatica L.). The new approach was that surface quality was assessed by following a tested method from previous research regarding the measuring and evaluation recommendations meant to reduce the biasing effect of wood anatomy, Also, a large number of roughness parameters were used for interpretation of the combined effect of processing and wood anatomy after filtering the data with a robust filter. Among those, Rk is the parameter that is least biased by wood anatomy and that best expresses the effect of processing alone. Electron micrographs were taken to visually assess the resultant surfaces. The results showed a gradual increase in processing roughness, as distinctively measured by Rk, which increased with longer durations of the treatment. Vessel cavities were deeper than those caused by processing and that influenced, among other parameters, Ra, which is most commonly used in literature to assess surface quality. The ray tissue, especially, exhibited both greater pull-out of fibers and a sort of plasticization with increased treatment time. The length of the thermal treatment reduced surface waviness. The results also showed that it was necessary to calculate the roughness parameters to differentiate between two similar surfaces rather than relying on visual and tactile assessments alone.

No abstract

The comparative behavior of heat-treated and untreated beech wood (Fagus sylvatica L.) were studied in response to planing. Beech wood samples were heat-treated in an electric oven without air circulation, at atmospheric pressure, at 200 °C for 1, 2, 3, 4, 5, or 6 h. After conditioning, both the heat-treated samples and the untreated controls were planed at a rotation speed (n) of 4567 rpm and a feed speed (u) of 10 m/min via a "silent power" cylindrical cutter. The cutting power was measured during machining by a Vellemann DAQ board. After processing, the surface quality was measured along and across the cutting direction with a stylus MarSurf XT20 instrument, and the processing roughness was assessed by the roughness parameter Rk. The influence of the heat-treating duration upon the cutting power and the processing roughness were analyzed and correlated to the mass loss after the heat treatment. Linear regression functions were generated for both of the correlations.

No abstract

This paper presents experimental research on the Computer Numerical Control (CNC) routing of a traditional motif collected from Ţara Bârsei (Transylvania region) using two methods, namely, engraving (Engrave) and carving (V-Carve). The analysis of the CNC router processes includes the calculation of the path lengths, an assessment of the processing time and wood mass loss, and an evaluation of the tool wearing by investigating the tool cutting edge on a Stereo Microscope NIKON SMZ 18 before and after processing the ornament on wood. An aesthetic evaluation of the ornament routed on wood, using both the engraving and carving methods, is also conducted, whilst a microscopic analysis of the processed areas highlights the defects that occurred on the wood surface depending on the tool path.