  Citation: Biszczanik, A.; Górecki, J.; Kukla, M.; Wal˛ esa, K.; Wojtkowiak, D. Experimental Investigation on the Effect of Dry Ice Compression on the Poisson Ratio. Materials 2022, 15, 1555. https://doi.org/10.3390/ ma15041555 Academic Editors: Antoine Ferreira, Szymon Wojciechowski and Krzysztof Tala´ ska Received: 8 January 2022 Accepted: 15 February 2022 Published: 18 February 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). materials Article Experimental Investigation on the Effect of Dry Ice Compression on the Poisson Ratio Aleksandra Biszczanik * , Jan Górecki * , Mateusz Kukla , Krzysztof Wal˛ esa and Dominik Wojtkowiak Institute of Machine Design, Poznan University of Technology, Piotrowo 3, 61-138 Pozna´ n, Poland; mateusz.kukla@put.poznan.pl (M.K.); krzysztof.walesa@put.poznan.pl (K.W.); dominik.wojtkowiak@put.poznan.pl (D.W.) * Correspondence: aleksandra.biszczanik@put.poznan.pl (A.B.); jan.gorecki@put.poznan.pl (J.G.); Tel.: +48-61-665-2053 (J.G.) Abstract: In the processing of waste materials, attention must be given to the efficient use of energy. The pelletization of dry ice is a good example of such processes. A literature review shows that in the pelletizers available on the market, the force applied in the process is excessive. As a result, the efficiency of the utilization of inputs, including electricity and carbon dioxide, is at a very low level. This article presents the results of experimental research on the effect of the degree of dry ice compression on the value of the Poisson ratio. The first part of this article presents the research methodology and a description of the test stand, developed specifically for this research, bearing in mind the unique properties of carbon dioxide in the solid state. The results presented show the behavior of dry ice during compression in a rectangular chamber for different final densities of the finished product. As a result, it is possible to determine the values of the Poisson ratio as a function of density, using for this purpose four mathematical models. The findings of this research may be useful for research work focused on the further development of this process, such as by using the Drucker–Prager/Cap numerical model to optimize the geometric parameters of the parts and components of the main unit of the machine used in the extrusion process of dry ice. Keywords: Poisson ratio; compression; densification; extrusion; dry ice; carbon dioxide (CO 2 ) 1. Introduction The available research reflects a growing interest in the use of numerical testing techniques in the planning process of various production processes, such as powder densification [1–3], the compaction of saw dust [4] or dry ice blasting [5]. This stems from the possibility of reducing the implementation costs related to the preparation of the prototype and carrying out the tests needed in the period before starting production. As a result, it is possible to improve the efficiency of production processes at the planning stage and in the process of designing relevant machines. The improved efficiency of processes in the area of the utilization of raw materials contributes to the reduction of production waste. This should be understood as a use of raw materials that can be considered both effective and efficient, which makes it possible to minimize losses along the process of transporting and using the materials in production—for example, natural gas liquids [6]. There is also material efficiency research aimed at improving design and recycling processes, such as [7]. This can be especially illustrated by the example of rare earth metals, the recycling rates of which are estimated at less than one percent [8]. A good example of production waste reduction is the use of polymer materials in additive manufacturing processes, such as polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), poly (vinyl alcohol) (PVA), and a number of others. The use of 3D printing technology generates less production waste than the subtractive methods of production. As a result, it is characterized by a number of advantages, including improved resource efficiency concerning both production and manufacturing processes [9]. Materials 2022, 15, 1555. https://doi.org/10.3390/ma15041555 https://www.mdpi.com/journal/materials