| In injection molding, uniform temperature distribution on the cavity surface is crucial for high quality and short cycle times. Especially the conventional water cooling of long, thin cores or other difficult-to-access areas faces severe problems, such as excessive heat, clogged runners, or unwanted pressure losses. The results are removal problems, surface defects, warpage, and long cooling times.
Temperature control with liquid carbon dioxide (CO2) efficiently cools the hot spots in the mold, such as very thin parts, small cores, or areas with material accumulations, resulting in enormous cooling time reductions and quality improvements. To do so, liquid CO2 flows under high pressure (approx. 60 bar) through small, flexible capillary tubes (outer diameter 1.6 mm) exactly to the point of use where the cooling is required. The CO2 expansion creates a snow and gas mixture with a temperature of -79 °C. After removing heat from the mold, the now gaseous CO2 leaves the cavity through exhaust channels.
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