Polypropylene is a widely used linear hydrocarbon polymer with diverse applications due to its exceptional physicochemical characteristics and minimal changes during the recycling process. Numerous studies have focused on factors influencing the mechanical properties of polypropylene and its application in composites. However, despite their significance in the agricultural industry, there is limited research on polypropylene baling twines. This study analyses the behaviour of polypropylene baling twine under tensile loading, exploring the influence of fibre friction and twisting angle on the material’s tensile strength. Experimental investigation indicated that tensile strength increases with twisting angle, but only until the angle reaches a critical value. Further increase in the twist angle led to a decrease in tensile strength. The increase in tensile strength is attributed to the rise in the coefficient of friction between fibres in the twine. An experimental approach was employed to evaluate the mechanical characteristics of the twine, including the effect of prestressing by twisting. Understanding these characteristics is crucial for enhancing the quality of polypropylene baling twines and optimising their application in the agricultural industry.

The paper investigates the effects of roller pressing on the hardness, roughness, and elastic modulus of wooden workpieces. For research purposes, a roller pressing device based on purely mechanical processing was designed and developed. Four different levels of pressing force have been applied to eight different types of wood: cherry, fir, alder, linden, beech, walnut, oak, and ash. The obtained results indicate that the proposed processing method can significantly improve the hardness, elastic modulus, and surface quality of wooden workpieces. The ash sample exhibited the largest relative increase in hardness (175.9%), while the most significant relative increase in the elastic modulus (66.73%) was measured on the linden sample. The largest relative decrease in surface roughness (54.75%) was achieved on the alder sample. For all types of wood except for fir, in which case an increase in pressing force did not produce the desired reduction of roughness, correlation coefficients indicate a strong relationship between the pressing force as an input variable and the elastic modulus, hardness, and roughness as output variables.

The application of mechatronic systems is very topical today. Today, mechatronic systems are applied in all areas, so today systems are also being developed that enable fast and simple production of products. Today's mechatronic systems that are supported by computers enable the development, easy and fast production of prototypes and products. Two technologies that are widely used are 3D printers and scanners. 3D printers allow a virtually developed product to be turned into a physical model, while the application of a 3D scanner allows a physical model to be turned into a virtual model on a computer. In this paper, a comparative analysis of two types of printers and their software was performed. They differ according to their working principle. In addition to the working principle, an example of the difference between the software used to write the G code to drive the printing process of 3D printer.