The main advantages of cutting with liquid jets are the flexibility and consistently sharpness of the tool, which allows the machining of a variety of materials and complex shapes. Unfortunately, the humidification of the components can be a problem for certain applications and inhibits the spread of jet technology. Besides, the dry and residue-free cutting of materials is an important topic of today’s research in manufacturing engineering. Due to these advantages, high-pressure liquid CO2 jet cutting has the potential to open new fields of applications in which water jet cutting is not suitable. The liquid CO2 jet with a pressure of up to 300 MPa can be used to machine various materials and functional surfaces before it expands to gas and atmospheric pressure. However, the transition from liquid to gaseous phase implicates density differences which change the cutting performance. As a result, the knowledge about waterjets cannot be adapted to CO2 jets and further investigations are necessary. A new test stand was put into operation and a feed line with abrasives was added. Technological investigations concerning the formation of kerfs with high-pressure liquid CO2 and water jets were performed with and without abrasives as well as subsequently analyzed. The cutting tests were carried out on parts of various metals and technical plastics. The influence of the fluid on the attained cutting surfaces and kerfs produced by the jet was investigated. The experiments indicate that the performance of the CO2 jet as well as of the waterjet depends mainly on pressure and nozzle diameter but show different separation behavior. Especially the impact of the working distance will be discussed. The investigations reveal that high-pressure liquid CO2 jet cutting has a high potential in the field of dry and residue-free cutting of metals, technical plastics and CFRP. Furthermore, no temperature influence was observed and the potential for jet cutting in 3D-applications and for hollow profiles was proven.

Graphical Abstract

Dry cutting with high-pressure liquid CO2 jets