The article presents the results of research on the effect of extrusion tube geometry on the axial force being the key parameter of the dry ice piston extrusion process. The tests were carried out with the experimental set-up based on a cylindrical extrusion tube used alone and supplemented with reducer (orifice). The focus of the experiments was to determine the effect of compression tube reducer on the value of the force of resistance FOP in the dry ice compression process. Its value can subsequently be used as the basis for establishing guidelines for designing and building machines for compression and pelletizing of dry ice.

The article presents the results of static compression tests of concentrated crystallized carbon dioxide. Included results of test describe relation between the agglomerating stress and density of compressed dry ice. Quality of dry ice pellet is determined by value of density. Results of research allow to determine the effective value of stress during the agglomeration process. Due to the fact that the crystallized carbon dioxide has temperature equal minus 78.5 °C and sublimates under normal conditions of the test was proposed the methodology which allowing performance the tests. In first stage of research has been determined value of bulk density of dry ice snow. This value is initial boundary condition of relation between compression stress and density of agglomerated material. In second stage of the research has been investigated influence of compression stress on to density variation of the agglomerated dry ice. Results of both stage of research allow for formulation of function which approximate relation between density of agglomerated dry ice and compression stress. Results will allow for formulation of assumptions, which will be one of main point to create a more efficient machine for agglomeration process of solidified carbon dioxide.

The article presents results of research on internal friction of agglomerated dry ice. The results allowed for approximations of the curve describing the relation between the material parameters as a function of limit compression stress of the agglomeration process of dry ice. The value of parameter of investigated material is needed to formulate a mathematical model. This model can describe the influence of geometrical parameters of the conical channel on the limit stress in the process of agglomeration of dry ice. Due to the fact that the crystallized carbon dioxide has temperature equal minus 78.5 °C and sublimates under normal conditions of the test there was proposed the methodology which allowing performance the tests. The study determined the curve describing the change of cutting stress vs. deformation. The tests were realized for samples having different degrees of densification. This allowed to describe the relation between shear stress and degree of densification of the agglomerated dry ice. Results will allow for formulation of assumptions, which will be one of main point to create a more efficient machine for agglomeration process of solidified carbon dioxide.

The article presents the results of study on the influence of geometrical parameters of the forming channels on axial force which is the main parameter of the agglomeration process of dry ice in the piston method. During research, the material was agglomerated utilizing different dies. The material is characterized by low temperature and sublimation under standard environmental conditions. The study focuses on determining the influence of geometrical parameters of the conical and cylindrical sections of the forming chamber which influence the value of yield stress in the carbon dioxide agglomeration process. The determination of the value of boundary force is the basis for formulating the construction assumptions which shall be the basis for designing and constructing the dry ice compaction and pelletization machine.

Most of the industrial machines use round-shaped drive belts for power transfer. These drive belts are often a few millimeters in diameter, and made of thermoplastic elastomer, especially polyurethane. Their production process requires the bonding step, which is often performed by hot plate butt welding. The authors have undertaken an effort to design an automatic welding machine, which calls for an analysis of the hot plate welding process consisting in describing the dependency between the technological parameters (temperature, pressure force, time) and the quality of the joint. To analyze this process in a proper way, it is necessary to describe the physical phenomena in the material during temperature and force impacts. In this case the research of thermomechanical properties of the belts is needed. The paper shows results of some preliminary research of the thermomechanical properties of the polyurethane. This research allows to predict the material reaction to increased temperature and force during hot plate welding.