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This research deals with the processing of wood using a circular saw, which is associated with several risks and factors that affect the wood-splitting process. One of them is the wear of the teeth of the saw blade that change the magnitude of the cutting forces. The aim of this study is to compare real measured values and theoretical values when processing Norway spruce wood using two types of saw blades, i.e., sintered carbide (SC) and high-speed steel (HSS), with a diameter of 600 mm and 54 and 56 teeth, respectively. Experimental measurements were carried out on a special test device with the possibility of moving the tested wood into the cutting devices and a simple saw blade replacement system. The results of the contributions show significant differences, based on defined factors which represent the cutting and feed speed, which are supported by FEM analysis of cutting forces in the process of cutting wood—when changing the design of the saw blade. The results of the experiment show that the cutting conditions (cutting speed and feed speed) do not have a significant effect on the size of the cutting forces. The theoretical and real stress values for HSS discs ranged from 14 to 22 MPa. Significantly larger differences were recorded for discs with SC, where the real values of the maximum stresses were around 14 MPa and the theoretical ones around 25 MPa. When cutting spruce with a disc with SC slices, the maximum values of the theoretical cutting forces were in the range of 76 to 94 N and the maximum values of the measured cutting forces were in the range of 40 to 44 N.

The design of a stationary disc wood chipping machine was considered, as well as the stress-strain analysis of a cutting knife with a flat and shaped cutting edge, which will produce a dimensional chip. The design consisted of the conceptual design of a cutting knife, a cutting mechanism, and an entire disc chipping machine, which includes cutting tools. The design solution is based on mathematical calculations of the individual parts of the cutting device. Calculations of the cutting mechanism and the cutting tool were performed using the finite element method. The results of the stress analysis found that the maximum stress acting on the edge of the knife during cutting corresponded to the permissible stresses of the knife material and subsequent use in practice. Based on the design and physical parameters of the wood cutting process, the design of the entire chipping machine was simulated and then was modeled using the PTC Creo parametric 5.0 program. Additional finite element analysis was performed using the Creo Simulate 5.0 software.

This article examined the impact of cutting speed and feed rate on the process of cross cutting with a saw chain. Three cutting speeds and three feed rates were chosen, and their impact on energy intensity was evaluated. The measurements were performed on an experimental device, on which it is possible to set the rpm (cutting speed) and the feed rate into the section using frequency converters. The cutting speed influences the resulting energy efficiency, at a cutting speed (vc) of 5.02 m × s-1 the resulting power (P) was 485 W. With increasing speed the cutting power increased, where the maximum value of P was 619 W at a cutting speed of 6.81 m × s-1. At a feed rate of 0.286 m × min-1 the cutting power was 376 W, with increasing cutting speed the cutting power (P) also increased almost linearly up to the value of 695 W at a feed rate (vf) of 0.857 m × min-1. The results showed that the cutting speed and the feed rate have a clear influence on the process of cross sawing with a saw chain.

Cutting mechanisms and the cutting force are the focus of this article. The cutting force can be determined theoretically or mathematically by statistical analysis. In this work, the cutting speed was compared when changing the diameter of the test wood and when using the three types of angular geometry of delimbing knives. Experimental measurements were conducted on a self-designed experimental pneumatic stand. Empirical relationships and values from the scientific literature were used to determine the input parameters. Based on a regression analysis, conclusions were drawn relative to factors affecting the process of delimbing. The angular geometry of the delimbing knife plays a significant role in the delimbing process. The thicker the knife, the higher the energy consumption in the cutting process and the poorer the quality of the cutting surface of the wood. The quality of chipless separation timber was found to depend on the cutting speed, and the optimal speed was 2.0 m s-1.

According to European Tyre&Rubber Manufacturers' Association (ETRMA), there are about 1 billion cars all over the world. If the interest in cars does not change, the number of cars is going to be increased and in 2030 there is going to be more than 2 billion cars in the world - regardless of whether they will be powered by a petrol engine or a completely different one at that time. Based on the studies, we focused on the design of the crusher whose task is to effectively recover plastic and rubber waste from used cars. The paper describes the stress - strain analysis of the cutting device of the crusher using a defined material for its production. The basic parameters of the crusher were investigated for a determined final cutting force. Based on the cutting force and the designed crusher, a finite element analysis (FEM) was performed confirming the correctness of the selected material for the production of the crusher for the processing waste materials. The basic parameters of the crusher were observed for determination of the final cutting force.

An analysis was conducted of the effects of cutting conditions in the cross-cutting of wood using circular saws. Gradual wear of the saw blade cutting wedges impacted the entire cutting process. Two different types of circular saw blades were used. One blade type featured sintered carbide tips and 54 saw blade teeth, whereas the other had high-speed steel with 56 teeth; both saw-blades were 600 mm in diameter with a rake angle of 20°. The two wood species were spruce (Picea abies) and beech (Fagus sylvatica). During sawing, the timber was fed at a velocity of vf = 6 and 12 m·min-1. The cutting speed (vc) was set at 60 m·s-1, 70 m·s-1 and 80 m·s-1. The saw blades were coated with three types of PVD coatings. The least energy intensive saw blade was a sintered carbide-free saw blade with a coating (AlTiN) at a displacement speed of 12 m·min-1 and cutting speed of 60 m·s-1 with a power of 1310,63 W. Any change of a saw blade considerably affected torque for all the wood species, so a particular type of saw blade will always have an impact on torque. Other parameters distinctively and individually influenced the process of wood sawing.

The paper focuses on measuring and evaluating the impact of selected technical and technological factors -the height of adjustable guides and stretching force - on the side deflection of the saw band of a joinery band saw. There is a detailed description of the ways the side deflection can be measured. In order to find out the intensity of the stretching force was used portable tension meter SANDVIK 5000, enabling to check the tensile stress in the saw blades of a gang saw or in the saw bands of a band saw. The actual experiment was conducted on a joinery band saw, at the cutting rate vc = 15 m·s-1. The results of the measurements confirmed the theoretical assumption of the impact of the selected technical and technological factors on the stability of the saw band, where the side deflection decreases with increasing stretching force and increases with increasing height of the guides. The stability of the saw band affects the quality of the surface to be treated, thus saving the cost of machining the workpiece and making work productivity more efficient.

This study focused on stress and strain analysis of the cutting force of a branch knife with a replaceable cutting edge. The replaceable edge forms part of the delimbing head, which is applied to the arms of a mechanical harvester working in forestry. Basic parameters of the knife and head of the harvester with the basic calculations necessary to determine the number of knives based on input parameters, such as wood diameter, woody plants, and determination of the cutting force acting on the cutting knife, were examined. Based on the cutting force and the design of the special cutting knife, a stress analysis and a finite element method (FEM) was performed. This study confirmed the correctness of the selected material to produce the delimbing knife, which was designed using a replaceable cutting edge. The output of the stress analysis is reported.

Cutting wood in the transverse direction is the most widespread in the logging process, and it is used in felling trees, shortening the length of trunks, and assortment production. In practice, it is particularly important that the entire wood processing process starts with the least energy-intensive process (i.e., the energy demand of the entire process). The aim of the study is to determine the effect of coatings on the energy demand of saw blades. The conditions of the experiment were taken from previous experiments. In the experiment, two types of saw blades of the same type, EN 41 9418 or 75 Cr1 (DIN 1.2003), were selected. Two types of saw blades (SB with SC (cemented carbide) slices and PK without SC (cemented carbide) slices) and two types of wood (beech and spruce) were used in the experiments. The saw blades were coated with three types of PVD coatings (physical method of layer deposition). The results show that the least energy-demanding saw blade is HSS_M (tool steel saw blade without SK blades with Maximizer coating) at a feed speed of 12 m·min−1 and a cutting speed of 60 ms−1, with a power of 1310.63 W. When sawing spruce wood, it was proven that the most energy-demanding saw blade is HSS_K_I at a feed rate of 12 m·min−1 and a cutting speed of 60 ms−1, with a power of 2113.56 W. The least energy-consuming saw blade is HSS_M at a feed rate of 12 m·min−1 and a cutting speed of 60 m·s−1, with a power of 1251.54 W. The results provide a comparison of the measured values of the performances of the cross-cutting wood process using a statistical program.

Waste tires (granulate) and selected plastics from the automotive industry were evaluated by using the tertiary (pyrolysis) and quaternary (calorimetry) recovering. Pyrolysis is proving to be an environmentally friendly alternative to incineration and inefficient landfilling. Currently, the main challenges for pyrolysis of plastic waste are unavailability and inconsistent quality of feedstock, inefficient and hence costly sorting, and last but not least insufficient regulations around plastic waste management. Waste plastics and tire materials were characterized by TG/DTG analysis, Py-GC/MS analysis and calorimetry. TG analysis of the investigated materials gives the typical decomposition curves of synthetic polymers. The tested samples had the highest rate of weight loss process in the temperature range from 375 °C to 480 °C. Analytical pyrolysis of the tested polymers provided information on a wide variety of organic compounds that were released upon thermal loading of these materials without access to oxygen. Analytical pyrolysis offers valuable information on the spectrum of degradation products and their potential uses. Based on the results of calorimetry, it can be stated that the determined calorific value of selected plastic and rubber materials was ranging from 26.261 to 45.245 MJ/kg depending on the ash content and its composition.