Cooling time: is there any plastic injection molding company that wouldn’t like to reduce it, and thus reduce cycle time? After all, a typical production cycle for a plastic part is 30 seconds to a minute, but cooling takes more than half of that cycle time. Time is money, so lowering cooling time directly impacts the bottom line.
The conventional solution has always been to drill cooling channels straight through the metal blocks of injection molds. Even though coolant is run through the channels to cool the mold and draw heat away from the part after it has been injected, the efficiency of that cooling process is severely constrained by the straight lines of the channels themselves.
For years, industry experts knew that if those cooling channels could conform to the shape of the part, cooling would be speeded-up. Finally, the technology is here and many are heaping accolades on it, such as “transformational” and “game-changing.”
There are a range of manufacturing options for producing a conformally-cooled mold. These include laser sintering, vacuum brazing, liquid interface diffusion, among others.
Even with little or no engineering analysis, conformal cooling will result in a 10% reduction in injection mold cycle time. But there is an inherent danger in scrimping on the engineering: you risk premature mold failure or lack of performance. because of poor design or inaccurate assumptions that were not identified and corrected.
But with just a bit more engineering analysis—such as flow analysis, computational fluid dynamics and finite-element analysis —a better quality mold and more cycle reduction can be achieved.
How much more? Perhaps 20% to 40% in some cases! Those are the kinds of reductions that spur CEOs to get out the pocketbook.
Vacuum-brazing is the method of choice for producing the largest conformally cooled production molds. Large molds for automotive parts have been made by this process. But whatever the method, conformal cooling is re-molding the way we think about reducing cycle time.