A major challenge in injection molding is an effective cooling. In particular, areas that are difficult to access and close to the contour, such as pins, can often only be inadequately cooled with fluids. The use of gas instead of water or oil enables cooling at higher initial temperatures and a reduction in the cooling channel diameter. Microchannels close to the cavity can be manufactured using the additive manufacturing process laser powder bed fusion (PBF-LB/M). Furthermore, PBF-LB/M enables entirely new structural designs for cooling with gas, such as lattice or porous structures. This work describes the development of an additively manufactured thermal management system for passive pressure reduction of carbon dioxide (CO2). In an isenthalpic process, the gas CO2 is depressurized from p = 6.3 MPa to ambient pressure p = 0.1 MPa within the cooling structures. Effects such as the sublimation effect (SE) occurring due to the phase change from liquid to gaseous and the Joule-Thomson effect (JTE) were simulated. The simulations were validated by experiments in which different additive cooling structures were tested. Further checks of the simulation were carried out by means of comparisons with formula calculations. Based on these simulations, the cooling structures were then geometrically optimized with the aim of maximizing the thermal performance Pϑ of the overall system. The final cooling structure was additively manufactured while adhering to the additive design specifications.
- Upon completion, participants will be able to identify potentials of additive manufacturing in mold making.
- Upon completion, participants will be able to develop highly complex cooling structures under consideration of the additive manufacturing constraints.
- Upon completion, participants will be able to explain the optimization process of additively manufactured cooling structures using simulation and experimental investigations.