Cooling simulation comparing traditional thermal pins to conformal cooling, showing more uniform temperature distribution and reduced cycle time in the optimized design. Source: Reaction Plastics Solutions
When three companies join forces to address an ongoing challenge with new technology, good things can happen. This was the case when K-Rain, a manufacturer of irrigation products, collaborated with Zero Tolerance LLC, Xact Metal and Reaction Plastics Solutions to find a solution to a cooling issue in one of its molds.
The story started like many in moldmaking: a customer wanted faster cycle times. In this case, K-Rain asked Steve Michon, founder of Zero Tolerance, to create conformal-cooled inserts because their traditional thermal pins were clustered in one area, creating uneven cooling. “Everywhere else in the mold was fine, but this section wasn’t cooling efficiently,” Michon says.
That's when he decided to try a different approach: 3D-printed conformal cooling inserts.
Michon had already experimented with outsourcing metal 3D printing but wanted to bring the process in-house. "I've always been fascinated by metal additive, but the machines were just out of reach for a long time." When Xact Metal's compact metal printer came along, the timing was right.
As-printed conformal cooling inserts produced in Corrax stainless steel directly on the metal additive build plate, before secondary processing. Source: Zero Tolerance
“This project with K-Rain was unique because we started without knowing for sure that conformal cooling would make a difference, but based on past experience and the experience of Scott Kraemer, senior sales manager at Xact Metal, we decided to go for it,” Michon says.
The cooling challenge was specific: the outer areas of the mold used traditional channels and inserts to achieve decent conformal cooling around the perimeter and top of the part. The problem was the thin cross-section near the core tip. Limited space meant limited cooling options. The team initially tried thermal pins, which proved ineffective at managing heat in that critical zone.
With Kraemer’s help, Steve and his team designed a set of conformally-cooled inserts made from Uddeholm's Corrax stainless steel. The solution kept everything else the same but replaced the core cap with a 3D-printed insert featuring conformal cooling channels that dramatically improved cooling efficiency in the hot zone, using the available space without compromising steel integrity.
The inserts were printed directly on the build plate, machined and EDM'd in-house and finished to an A2 polish, which met the customer’s requirements.
The customer's facility in the Dominican Republic made material choice critical. Corrax was ideal because it can be hardened, polished and welded, while resisting corrosion in the region's salty air.
Conformal-cooled insert after heat treatment and final machining, including EDM work and surface finishing to meet tight tooling tolerances. Source: Zero Tolerance
Simulation Meets Reality
“Once the inserts were built and installed, K-Rain's new tool ran 10 seconds faster per cycle, dropping from 54 seconds to around 44, an 18-20% improvement,” Michon says. While a servo motor upgrade contributed about two seconds of that gain, most of the improvement came from faster, more uniform cooling.
This case is unique because the simulation was run after the modified tool had already been built and tested. That gave Richard Evans of Reaction Plastics Solutions real-world data to compare against the virtual results. “The two lined up remarkably well, demonstrating how accurate modern simulation has become,” Evans says.
The analysis revealed dramatic differences in temperature distribution. “With the original thermal pins, temperature mapping showed a large hot spot at 31 seconds into the cycle. With the conformal cooling design, the heat is much more evenly distributed and dissipates faster,” Evans says.
This uniform temperature profile directly translated into consistent part cooling, reduced shrinkage variation, and eliminated warpage and sink marks that were impacting the top of the part.
The simulation also validated the cooling circuit's performance, showing good Reynolds numbers and a manageable pressure drop of around 40 PSI, which are critical factors for multi-cavity tooling applications.
"Of course, running a project like this without simulation is risky," Evans notes. "A simulation might cost a few thousand dollars, while redesigning and re-machining tooling can run far more expensive if things don't work out." In other words, the simulation validated what the toolroom already proved and reinforced the value of using software analysis before cutting or printing steel.
Final assembly of the mold insert, incorporating conformal cooling only in the top portion where heat concentration and cooling limitations were most severe. Source: Zero Tolerance
Lessons From the Shop Floor
The team also shared a few hard-earned lessons that go beyond cycle-time savings:
- Conformal cooling isn't plug-and-play. Even a perfect-looking design can perform poorly without simulation. Sometimes a channel that looks right on paper will actually increase cycle time if it doesn't manage heat the way you expect.
- Additive doesn't replace machining; it complements it. As Michon put it, "There's no such thing as the one-button theory. You don't just print a mold insert, drop it in the press and start molding." Every printed insert still needs machining, benching and polishing to meet tight tolerances.
- Material and water chemistry matter. Mixing metals like aluminum and stainless in the same water system can create corrosion problems due to opposite positions on the alkaline scale. Paying attention to pH balance and filtration is just as important as good design.
- Teamwork drives success. Each partner brought something critical: Michon's toolmaking experience, Kraemer's additive knowledge and Evans' simulation expertise. Together, they turned an experiment into a proven process K-Rain now plans to replicate in future molds.
What Moldmakers Can Take Away
For mold shops exploring metal additive, this project offers a few takeaways:
- Start small with a single insert or problem area.
- Always validate with simulation before you print.
- Treat additive as another tool in your toolbox, not a replacement for your existing skills.
- Lean on partners. The collaboration between design, simulation and production makes all the difference.
Completed four cavities for the production mold with conformal-cooled inserts installed, delivering faster, more consistent cooling and improved part quality. Source: Zero Tolerance
The bottom line is that what began as a trial run for one cooling challenge turned into a case study in modern moldmaking. K-Rain achieved faster cycles, higher-quality parts, and a new level of confidence in the process. For the rest of the industry, it's a reminder that when you mix the right technology with the right people, progress isn't just possible; it's measurable.
