Cutting, as the most widely used machining process, is applied in both primary and secondary wood processing. Optimum cutting conditions that result in the high quality of the machined surface and low energy consumption are crucial for wood processing. The effects of the feed speed, cutting speed and average chip thickness on the energy consumption and surface temperature of a circular saw blade during the cutting process of two types of plywood with a thickness of h = 14 mm is described in this paper. In experimental measurements, two circular saw blades with cutting tungsten carbide inserts for wood were used as tools. One circular saw blade was standard, and was not surface treated (CSB1), and second circular saw blade (CSB2) differed by the powder coating surface and the length of the cutting edge. In the experiment, the energy consumption and the surface temperature of the circular saw blade was measured in order to find the optimal cutting conditions for the most energy-efficient cutting process. The results show that the cutting power and the surface temperature of the circular saw blade increased when the feed speed increased. The investigated values of the surface-treated circular saw blade were lower compared to the values of the standard circular saw blade. When comparing the lightweight plywood with the classic plywood, experimentally obtained cutting power values of the circular saw were made 19% lower on average by using the circular saw blade CSB1. When using the CSB2 circular saw blade, these values of the cutting power of the circular saw were 22% lower on average. The surface temperature of the circular saw blade is the highest on the outer edge (tooth root area 31.7 °C) and decreases towards the center of the circular saw blade. There must be a reasonable compromise between machine productivity and energy consumption.

The paper is focused on the bending properties of beech plywood made from veneers with perforations. The modification of the plywood was done by the targeted perforations in veneers used. The perforations were rectangular in shape 5 × 30 mm. There was a gap of 10 mm between the perforations (in each direction) and the perforations in the individual rows were shifted by 10 mm relative to each other. Two structures of lightweight plywood were investigated: sheathed (lightweight type 1) with perforated inner layers sheathed with solid veneer and perforated (lightweight type 2) with perforations in each layer. Bending properties were evaluated by three-point bend testing. The results showed decreased bending strength (MOR) as well as decreased modulus of elasticity in bending (MOE) with reduction of weight. Bending strength (MOR) was reduced by 33 to 57% and modulus of elasticity (MOE) by 13 to 43% compared to standard (non-lightweight) plywood. Bendability of lightweight plywood expressed by the minimum bending radius (R_min) and the coefficient of bendability (k_oh) point to a slight decrease in bendability by 1 to 35% compared to standard (non-lightweight) plywood. The benefit of the proposed plywood lightweight constructions is weight reduction by 16.5 to 24.4%.

Additive manufacturing offers opportunities to improve material efficiency and support more resource-efficient production of furniture components by reducing material consumption while maintaining sufficient mechanical performance for practical use in wooden structures. This study evaluated the effect of perimeter count and cubic infill density on the mechanical behaviour and material efficiency of FDM-printed dovetail connectors made from recycled PLA+ and used in wooden frame corner joints. Connectors were manufactured with three infill densities (20%, 30%, and 40%) and three perimeter configurations (1P, 3P, and 5P). Mechanical tests were performed on beech wood (Fagus sylvatica L.) corner joints, and maximum bending moment, rotational stiffness, and specific maximum bending moment were evaluated. The experimental results were supported by a homogenized shell–core FEM model used to analyse contact behaviour, load transfer, and critical stress regions. Perimeter count had a statistically significant effect on the maximum bending moment, whereas infill density did not. Among the evaluated configurations, 3P30 exhibited one of the highest mean bending moments (14,998 N·mm) and the highest mean rotational stiffness (6172 N·mm/deg), whereas 3P20 achieved the highest specific maximum bending moment (3903 N·mm/g). Increasing infill density to 40% increased material consumption and printing time without proportional mechanical improvement. FEM analysis showed that configuration 3P30 achieved the highest contact pressure, frictional stress, and reaction force among the analysed 3P variants, whereas increasing infill density from 30% to 40% reduced sliding but did not improve the overall mechanical response of the joint. The results indicate that appropriate selection of perimeter count and infill density can improve material efficiency by reducing material consumption while maintaining the mechanical performance of FDM-printed furniture connectors, thereby supporting more resource-efficient and sustainable furniture manufacturing.

A polyurethane coating represents the conventional solution for protecting and finishing visible wooden furniture surfaces. However, the increasing use of additive manufacturing has introduced visible 3D-printed polymer components whose surface mechanical performance is relevant to their application in furniture. This study investigated the effect of short-term exposure to 60 °C for 1 h on the surface mechanical properties of a pigmented polyurethane coating applied to oak wood and 3D-printed PLA, ABS-T and PET-G components. Specimens were evaluated under laboratory conditions (20 °C) and immediately after exposure to 60 °C, while their surfaces remained at an elevated temperature. Impact resistance, abrasion resistance, and scratch resistance using a tungsten carbide tip were determined according to the relevant standards, and the surface damage was assessed by visual inspection and digital microscopy. The polyurethane coating exhibited the smallest impact indentation diameter but showed earlier crack initiation and lower abrasion resistance than the 3D-printed polymers. Among the investigated polymers, ABS-T provided the most balanced combination of impact resistance, abrasion resistance and surface hardness, whereas PLA exhibited the greatest dimensional changes after exposure to 60 °C. Microscopic analysis revealed surface defects that were not detectable by visual inspection, demonstrating the value of digital microscopy for detecting subtle surface damage. The results indicate that ABS-T is a promising material for visible furniture components exposed to short-term elevated temperatures, while PET-G should be used with caution in applications exposed to radiant heat or direct sunlight.