The paper presents mathematical models describing the moments of resistance to cutting on the cutting drum shafts in the biomass cutting process. The mathematical procedures described in the paper have been verified on a test stand developed and constructed by the authors, which reflects real conditions of the process of cutting plant material into pieces of specified lengths. Experimental verification proved that the developed mathematical models are adequate for drums of both cylindrical and conical constructions. The value of the average error did not exceed 13%. Following the mathematical elaboration and verification studies, the authors carried out calculations for machines currently available on the market that are equipped with drum cutting units. The calculations were carried out for the most commonly cut material, i.e. for maize, straw and green plant materials. The obtained results confirm the complexity of the problem arising from a wide range of numerical values of cutting resistance, which is contained in the range of 400–1,800 nm. The compiled database can be practically applied in the selection of machines for specific field works, and the mathematical models developed and verified in the study can be applied at the stage of designing new designs of cutting drums used in forage harvesters.

The aim of this study was to examine the functional characteristics of the process of cutting surgical gauze with a drum cutting unit. For this purpose, the authors designed and constructed a test stand on which experimental tests were conducted. As part of this study, the results of the experimental tests are presented, which were conducted for three selected thicknesses of surgical gauze samples, four selected angles of feeding of the material to be cut and nine selected cutting speeds. In order to determine cutting resistance, the specific cutting resistance was used, and the energy consumption was estimated using the specific cutting work related to the cutting surface of the surgical gauze. The conducted experimental studies demonstrated that the highest value of the specific cutting resistance $p_c=78.14 \mathrm{N}\cdot {\mathrm{m}}^{-1}$ occurred during the cutting of eight-layer gauze at a cutting angle $\alpha =0°$ and a cutting speed $V_c=0.66 \mathrm{m}\cdot {\mathrm{s}}^{-1}$. Meanwhile, the highest value of the specific cutting work was approximately $L_{jS}=120.00 \mathrm{J}\cdot {\mathrm{m}}^{-2}$ during the cutting of three-layer gauze, also at a cutting speed $V_c=0.66 \mathrm{m}\cdot {\mathrm{s}}^{-1}$ for cutting angles $\alpha =0°$ and $\alpha =5°$. This study found that $V_c=0.66 \mathrm{m}\cdot {\mathrm{s}}^{-1}$ is the threshold cutting speed at which the material is cut. Below this speed, the cutting drum does not have enough momentum to cut the material. Based on the statistical analysis of the obtained test results, it was concluded that there exists a relationship between the independent and dependent variables. The cutting speed has the greatest impact on the parameters of the surgical gauze cutting process. The test results, which have not been found in the worldwide literature to date, constitute a valuable contribution to the development of the theory of surgical gauze cutting. The experimentally determined specific cutting resistance p_c and specific cutting work of surgical gauze broaden the knowledge of the materials used in medicine and contribute to the expansion of scientific knowledge in this field.

The aim of this study was to determine the effect of selected parameters of the machine-cutting process of multilayer surgical gauze on the accuracy of the spacing of successive cuts in a material roll intended for dressing production. The experiments were conducted on an original test stand equipped with a drum cutting unit. Three variants of the number of surgical gauze layers were analysed: 3, 4, and 8; four cutting angles: 0°, 5°, 10°, and 15°; and nine cutting speeds ranging from 0.66 to 3.34 m·s⁻¹. The relative spacing error between successive cuts, δ_L, was adopted as a measure of process accuracy and was expressed as the percentage deviation of the actual distance between cuts from the theoretical value. For each parameter configuration, the value of δ_L was determined on the basis of five replicate measurements. The results showed that cutting accuracy varied with the cutting angle, the number of layers, and the cutting speed. The lowest error values were obtained during transverse cutting at an angle of 0°. The mean value of δ_L increased from 1.61% at 0° to 2.91% at 15°. Increasing the number of layers also resulted in an increase in the error; the mean values were 2.25%, 2.33%, and 2.59% for 3-, 4-, and 8-layer gauze, respectively. The effect of cutting speed was nonlinear. The lowest mean error values were observed at intermediate cutting speeds, whereas higher mean error values were obtained at 3.00 and 3.34 m·s⁻¹. The minimum value of δ_L, equal to 1.20%, was obtained for 3-layer gauze at a cutting angle of 0° and a cutting speed of 1.33 m·s⁻¹, whereas the maximum value, equal to 3.57%, was obtained for 8-layer gauze at a cutting angle of 15° and a cutting speed of 3.34 m·s⁻¹. The results indicate that the highest cut-spacing accuracy can be achieved during transverse cutting of the material, with a lower number of layers and at moderate cutting speeds. The findings can be used to select the operating parameters of drum cutting units used in machines for the production of surgical gauze dressings.

This paper investigates the mechanical performance of thin-walled tubular structures with chambered (lattice) internal geometries manufactured from ABS using fused deposition modelling (FDM). The objective of the study was to evaluate the influence of infill geometry on load-bearing capacity and deformation behaviour under bending and compressive loading conditions and to compare lattice configurations with solid struc-tures. Experimental investigations included three-point bending and axial compression tests performed using INSTRON testing machines. Four structural configurations were analysed: ladder-type, triangular, tubular, and solid. In addition, finite element method (FEM) simulations were conducted to investigate the displacement response of the structures under compressive loading. The experimental re-sults showed that the solid structure achieved the highest load-bearing capacity but at the expense of increased mass. Among the lattice con-figurations, the ladder-type structure demonstrated the most favourable overall performance, reaching load levels close to those of the solid structure while reducing mass by more than 50%. The triangular structure provided intermediate performance, whereas the tubular configuration exhibited the lowest load-bearing capacity in both bending and compression tests. FEM simulations reproduced the displacement-response trends of the investigated geometries and provided qualitative insight into the influence of chamber geometry on structur-al behaviour. The results confirm that appropriately designed lattice structures can achieve a favourable load-bearing-capacity-to-weight ratio, making them attractive for lightweight engineering applications.