No abstract

Airborne wood dust poses health and safety risks in the construction and furniture industry. The study verified whether the thermal modification affects the share of fine wood dust particles (< 10 μm) generated during spruce, oak, and meranti wood sanding. The experimental research involved nine material variants, including three wood species in three states: untreated, thermally modified at 160 °C, and thermally modified at 220 °C). To collect at least 200 g of each dust sample, a belt sander with P80 sandpaper and a belt speed of 10 m/s was used, along with a dust collector. The collected dust was then separated into fractions using a set of sieves with aperture sizes of 2000, 1000, 500, 250, and 125 μm. A laser particle sizer was employed to measure the sizes of dust particles in the under-sieve fraction (dust with particle sizes smaller than 125 μm). The under-sieve fraction was decomposed into three subfractions, with particle sizes: <2.5, 2.5-4.0, and 4.0–10 μm. Surprisingly the results indicate that sanding dust from thermally modified wood generates a lower average mass share of potentially harmful fine particle fractions than dust from untreated wood. Oak dust contained a higher mass share of fine particles compared to the spruce and meranti dust samples. Dust from thermally modified oak and meranti wood had a lower content of harmful particle fractions than dust from untreated wood. The average mass shares of these dust fractions for modified wood at 160 and 220 °C showed no statictically significant differences (p < 0.05). Conversely, spruce dust had a low content of fine fractions because spruce particles exhibit a more irregular elongated shape. The study considered the extreme temperatures of 160 and 220 °C used in the thermal modification of wood. Therefore, the above statements are assumed to be valid for all intermediate thermo-modification temperatures.

Airborne wood dust causes health and safety hazards in the construction and furniture industry. The study verified whether the thermal modification affects the share of the finest wood dust particles (< 10 μm) created by sanding oak, spruce, and meranti wood. The experimental research included nine variants of materials (three species of wood in three states: untreated, thermally modified at 160°C, and thermally modified at 220°C). A belt sander with a dust collector allowed the collection of at least 200 g of each dust variant (P80 sandpaper and 10 m/s belt speed). Next, a set of sieves with 2000, 1000, 500, 250, and 125 µm aperture sizes was used to recognize the gradation of the wood particle aggregate. A laser particle sizer was used to determine details of dust with particle sizes smaller than 125 μm. The size distribution of the finest particles was analyzed in four fractions with particle sizes < 2.5, 2.5-4, and 4-10 μm. The results show that, surprisingly, sanding dust from thermally modified wood generates a lower average mass share of potentially harmful particle fractions than dust from untreated wood. When comparing tested wood species, it is noticed that oak dust has a higher proportion of the best particles than spruce and Meranti dust. Dust from thermally modified oak and meranti has a lower content of harmful particle fractions than dust from untreated wood. The average mass shares of these dust fractions formed during the sanding of modified wood at 160 and 220°C are not significantly different (p <0.05). The opposite was observed in the case of spruce wood because spruce dust has a low content of fine fractions, and its particles have a more irregular elongated shape. The study took into account the extreme temperatures used in the thermal modification of wood (160 and 220°C), then it can be assumed that the statements mentioned above are valid in all intermediate thermos-modification temperatures.

The objective of this study was to determine the effect of the moisture content on cutting parameters and fracture characteristics of spruce and oak wood. Samples of Norway spruce (Picea abies (L.) H. Karst.) and English oak (Quercus robur L.) were dried to required moisture content and then used for the machinability test on circular sawblade machine. Results indicate that cutting force and feed force increase with increasing moisture content up to the fiber saturation point (FSP). When the moisture content increases above the FSP, the minimum values of cutting and feed force are achieved. Based on performed experiments, the fracture toughness and shear yield strength were derived. Fracture toughness decreases with increasing moisture content. The minimum values of fracture toughness are achieved at the moisture content level above the FSP. Shear yield strength decreases linearly with increasing moisture content: the decrease is up to 17 % compared to samples with moisture content at the FSP. Based on calculated results, the influence of moisture content and wood species on cutting and fracture characteristics was discussed.

The TechnoPORTA technology line is a fully automated smart line ensuring the highest quality and efficiency of production wooden doors. The aim of the study was to experimentally determine the performance of the edge banding module in the TechnoPORTA line on particular working days and to determine the possible influence of organizational and technological factors characterizing the line’s operation, which can be defined and determined by analyzing the temporal technological data obtained from the IT systems controlling the line’s operation. The research was conducted on the edge banding module, which is crucial to the performance of the entire TechnoPORTA line. During the study, data on door leaf machining were collected such as the mean time of production per one working cycle, mean time of retooling, number of retooling, number of door leaves leaving in a series, and most frequent time of series. The data collected by the IT system controlling the line indicates that this module is flexible and its performance is not related to the control parameters. The results can be used to improve the operation of the module and the replication of the work schedule to subsequent modules of the technological line.