Julie Cool

Improving the Sanding Process of Black Spruce Wood for Surface Quality and Water-Based Coating Adhesion

The sanding of black spruce wood prior to coating application was optimized for feed speed and grit size. As feed speed increased, the surface roughness and the surface energy of the samples increa...

Anatomical evaluation of wood surfaces produced by oblique cutting and face milling

The condition of superficial tissues plays an important role in the behavior of adhesive/wood interfaces. Tissues at the wood surface should be the least distorted possible during surfacing in order to avoid the formation of mechanical weak boundary layers. These layers cause significant loss of adhesion of coating films and gluelines during utilization of wood. In this study, sugar maple (Acer saccharum Marsh.), northern red oak (Quercus rubra L.), and eastern white pine (Pinus strobus L.) were surfaced by oblique cutting and face milling, while paper birch (Betula papyrifera Marsh.) was face milled. Cell damage was considerably higher in face milling than in oblique cutting. This damage was manifested in the form of lateral distortion, bending, and rupture of tissues. In general, superficial cell damage presented similar patterns for all species studied, but its severity was quite variable as a function of species and cutting conditions. The present study describes damage patterns and discusses the possible implication of cell damage in wood finishing and gluing.

A review on wood machining: characterization, optimization, and monitoring of the sawing process

ABSTRACT Sawing is the most common machining process and is present in both primary and secondary wood transformation sectors. The objective of this paper is to review how it is affected by different factors. The current challenges associated with various machining factors, process monitoring, and sensor selection were identified and explained. Consequently, four research challenges and technological gaps were outlined. (1) Contradictory results have been reported due to different cutting processes, wood species, measurement methods, and cutting speed range studied in literature, so special consideration needs to be taken when comparing results with those available in the literature. (2) Laboratory test conditions cannot yet fully represent the extreme cutting conditions in sawmills. More emphasis should be placed on those harsh industrial cutting conditions. (3) Research on wood cutting lacks multi-objective optimization approach, which suggests that sawdust generation should be simultaneously analysed with surface quality and power consumption. (4) Compared with metal cutting, little research has been conducted on wood sawing monitoring using an artificial intelligence approach, which should be prioritized in designing adaptive control systems. Combining intelligent monitoring and multi-objective optimization approaches should pave the way for controlling the sawing process so higher surface quality and cost efficient machining is achieved.

The effect of rotation speed on the power consumption and cutting accuracy of guided circular saw: Experimental measurement and analysis of saw critical and flutter speeds

ABSTRACT This paper investigates the effect of rotation speed and vibration response of a circular saw on the sawing process of Douglas-fir wood. An idling test was conducted on a guided circular saw to determine its stable operation speeds and vibration behavior. Short-time Fourier transform analysis was performed on saw idling test data, and variation of excited frequencies of the blade as a function of rotation speed was obtained. The saw blade critical speeds and the rotation speeds that correspond to saw flutter instability were identified. Then experimental cutting tests were conducted at different cutting conditions and the effect of rotation speed and saw vibration response on cutting power consumption and sawing accuracy was investigated. The results showed that conducting a saw idling test and vibration response analysis can identify the saw critical and flutter speeds, which is essential for identifying the optimum rotation speed of circular saw. There was a significant increase in power consumption when cutting at super-critical and super-flutter speed. The effect of rotation speed on sawing accuracy is complex and nonlinear. This effect interacts with feed speed, which makes it difficult to generalize sawing accuracy versus rotation speed in the circular sawing process.