Special Issue on Advances in Wood Processing Technology

An Overview of Published Articles

The primary goal of this Special Issue, “Advances in Wood Processing Technology”, was to showcase cutting-edge research and development in the field of wood-based materials. It aimed to promote innovative approaches for processing wood, creating novel ecological composites, enhancing wood processing functions, and optimizing industrial production processes. Ultimately, this Special Issue sought to contribute to the advancement of wood as a sustainable and high-performance construction material by addressing the challenges and limitations of traditional wood-based materials.

Wood, a naturally abundant and renewable resource, offers numerous advantages as a construction material, including strength, durability, and aesthetic appeal. However, its susceptibility to fire, dimensional instability, and biological degradation poses challenges for its wider application [1]. This Special Issue focused on addressing these limitations through technological innovation [2]. By exploring new processing techniques, developing advanced wood-based composites, and optimizing industrial production, researchers aimed to unlock the full potential of wood as a high-performance material [3].

The first article [4] concludes that wood density directly affects its Brinell hardness and capacity for self-re-deformation. Specifically, denser woods like beech have a lower percentage of permanent indentation, indicating a higher ability to recover shape. This recovery ability in radial and tangential sections is influenced by both density and applied force, whereas in longitudinal sections, it is solely dependent on density. This study highlights that side compression of wood cells is mostly reversible, contrasting with the irreversible damage caused by longitudinal deformation.

The aim of another paper [5] was to investigate the possibilities of increasing the lifetime of woodworking tools through the application of thin hard layers. These layers, applied by physical or chemical vapor deposition methods, have the potential to significantly increase the wear resistance of tools. The results of this study show that multi-layer coatings, especially chromium-based coatings, are the most promising. Coatings with a lower coefficient of friction were found to exhibit higher wear resistance. This property has been shown to be a more important predictor of tool life than the hardness of the coating itself.

The primary goal of the article [6] is to optimize the CO₂ laser cutting process for spruce wood by using an artificial neural network (ANN) to predict cut characteristics. This article specifically focuses on identifying the critical role of laser performance and cutting speed in wood cutting quality and efficiency, developing an ANN model to predict cutting kerf properties and the heat-affected zone based on laser power and the wood’s annual ring count. The next section addresses the verification of the model predictions against the existing literature [7,8,9,10] and finally proposes the determination of the optimal laser power to achieve the desired quality of spruce wood cut.

The study [11] analyzed the performance of the edge banding module in a fully automated wooden door production line. By examining production data, researchers aimed to identify factors influencing module efficiency. Results indicate that the module operates flexibly and independently of control parameters, suggesting potential for operational improvements and optimized work scheduling across the entire production line.

The article [12] by Koleda et al. was focused on the determination of the size of wood dust particles generated during milling of chipboard using an experimental optical method. The results showed that the proposed optical method allows more accurate determination of particle size and shape compared to the traditional sieve method. This method provides more detailed information on the composition of wood dust, which can be useful for further research and applications.

The article by Hortobágyi et al. [13] investigated the feasibility of using vibration monitoring on a pneumatic gripper for adaptive control during the milling process. This study analyzed vibration data collected during milling operations, employing fast Fourier transform to identify the dominant frequencies related to tool cutting [14,15]. Statistical analysis revealed that tool type, spindle rotation, and material significantly influenced vibration patterns. While feed rate showed less impact, the results suggest that vibration monitoring can potentially serve as a valuable signal for adaptive control. Future research will focus on combining vibration data with surface roughness measurements and developing a smart pneumatic gripper for the woodworking industry.

The research by Suleiman et al. [16] shows the potential to increase the value of Portuguese eucalyptus forests by using them for glulam production. This research succeeded in producing glulam from eucalyptus without changing the standard production process. The resulting glulam exceeded the strength requirements for high-strength softwood glulam.

The aim of the paper by Abdullah Beram [17] was to improve the properties of black poplar wood through impregnation with calcium oxide solutions. This research compared vacuum and immersion impregnation methods, using different solution concentrations. The results showed that both methods improved the wood’s thermal stability and flame resistance while reducing water absorption and swelling. The impregnation process also affected the wood’s surface properties, increasing roughness but decreasing water contact angle. This study concludes that calcium oxide is effective in improving the overall performance of black poplar wood.

The study [18] compared the embedment strength of cross-laminated timber (CLT) reinforced with glass fiber-reinforced polymer (GFRP) or densified wood. The results showed that both reinforcement methods improved embedment strength, with densified wood offering the highest values. The embedment strength was higher when the load was applied parallel to the outer layers of CLT [19]. The NDS formula (National Design Specification) provided the most accurate prediction of embedment strength compared to other models. This study concludes that both densification and GFRP reinforcement can enhance CLT performance, but densification appears to be a more effective option.

A recent paper by authors Marina Chavenetidou and Vasiliki Kamperidou [20] investigated the surface roughness of chestnut wood in different anatomical regions and trunk heights. This research found that surface roughness varied significantly depending on the orientation of the wood grain, with measurements perpendicular to the grain resulting in higher roughness values. While no significant differences were observed between heartwood and sapwood roughness, tangential surfaces exhibited the highest roughness overall. This study concludes that surface roughness in chestnut wood is primarily influenced by wood grain orientation and is consistent across different trees and trunk heights.