Analytical assessment of the linear displacement of the center of mass of the pressure segment during the die-cutting process of cardboard packaging blanks

The production of cardboard packaging blanks involves a set of operations, one of which is die-cutting. For this purpose, presses with a flat die-cutting method are used. A disadvantage of this method is the significant technological loads, which can reach several hundred tons. The article presents an analysis of publications dedicated to improving die-cutting presses and reducing technological loads. It has been established that the reduction of loads can be achieved by decreasing the contact area in the press pair. However, the existing studies only concern the retrofit of offset printing machines for die-cutting purposes. In this case, a small-diameter cylinder is used to create pressure. This leads to technological problems and poor-quality, inaccurate die-cutting. The authors' research on the use of a large-radius segment to create process pressure in a die-cutting press was further developed in the article. The scheme of a crank-gear mechanism for driving the carriage with a pressing segment is considered. The displacement of the center of mass of the segment is studied for the optimised relative geometric sizes of the mechanism from previous works. For the accepted relative values of the radius and width of the segment, a condition is determined when it passes half of the path during die-cutting. The asymmetry of the oscillation angle of the segment relative to its horizontal position is substantiated. The nature of the change in the relative horizontal and vertical components of the displacement of the center of mass of the segment is investigated. Quantitative indicators of the change in the center of mass displacement are determined. Based on the results of the analytical research, the use of a large radius segment is justified in order to minimise the maximum values of the components of its center of gravity displacement. The research on the linear displacement of the center of mass of the pressing segment creates the conditions for developing an additional means to reduce the impact of the bending moment on the carriage from the segment's weight in extreme positions.