How to Clean and Maintain Molds With Intricate Conformal Cooling Channels

Mold cleaning is one of the most essential steps in making plastic products. When those products include sensitive medical devices created via molds featuring intricate conformal cooling channels, those molds require a cleaning system that is just as precise.

That’s why Rankine-Hinman Manufacturing, based in St. Augustine, Florida, which services the unconventional molds of a leading plastics healthcare molder among other customers, relies on the Eco-Pro XL system of mold cleaning carts and cleaners from LaGrange, Illinois’ iD Additives. Initially used to restore the function of clogged molds, the Eco-Pro system is now used for preventive maintenance (PM).

Addressing Zero Flow-Through

Rankine-Hinman owner and president Bryan Hinman explains that clogged cooling lines can cause parts to stick in the mold. To make matters more challenging, the molds used to produce a tiny, thin, curved part also feature uniquely shaped cooling channels that surround the part in hard-to-reach areas to ensure heat is removed evenly.

Rankine’s healthcare customer puts flowmeters on all of its mold cooling channels and found several channels with zero flow-through. The customer researched solutions and purchased two iD Additive Eco-Pro carts in 2018 and the results were immediate. Using flow rates of up to four to five gallons a minute, the benefits became obvious quickly. “One mold took 16 hours to break free, but Eco-Pro did the job,” Hinman says.

The customer demonstrated the Eco-Pro on six molds before turning the system over to Rankine, which has supported various production needs for this customer for more than 25 years. Hinman adds that the customer sends molds to Rankine when a mold’s flow rate falls below a certain threshold. “They tell us it is a significant improvement each time Eco-Pro is used.”  

3GT molds (three-plate, gated, threaded) were the customer’s main pain point prior to introducing Eco-Pro into the maintenance regimen. The customer initially attempted to clean the mold channels using ultrasonic baths and other methods but was unsuccessful due to a hairpin turn that made it impossible to insert a brush — or even a drill — manually. Eco-Pro saved the customer money by preventing corrosion in these molds, which are prone to leaking through a hot runner plate or a crack in the face plate. This prevention averted a $70,000 failure.

Moving from Repair to Prevention

Hinman explains that the use of the Eco-Pro system has recently evolved. “Setting up and running it right out of the box was easy,” he explains. “We just needed to ensure we had the correct fittings for the molds. We would attempt to flush and open up some channels. Before and after this process, we’d take measurements to verify the mold’s function.” Rankine-Hinman has seen what the Eco-Pro system can do to clean molds. With this technology, the customer is even performing more PMs to prevent restrictions in the lines.

Over time, Eco-Pro’s ease of use has greatly streamlined cleaning times for this customer. “They’ve reduced the amount of attention they give to cleaning to the point where they can hook it up and trust that the chemical will do its job. It may require monitoring, but they no longer have to constantly monitor it,” Hinman explains.

The company will revisit it after it’s been running for 45 minutes to an hour, then run water through and check to see if there’s any difference. If they don’t see a significant improvement or the numbers they want, they hook it back up and let it run a little longer.

“We’ve flushed two or three molds a week now. We have a truck going back and forth to that customer and I know they can count on us and the chemical to service all of their molds.”

The customer also periodically checks the filters to monitor the contents of the discharged water. During the flushing process, they open a line and inspect the water to identify any changes. This enables them to distinguish between what has been broken up in the channels and what is coming out of the molds.

“While they trust that the chemical is effective, they also rely on visual inspections to ensure that the discharge and water are being cleaned properly,” Hinman says. “They tell us they even put their hands on the hoses and feel everything running through the channels to ensure that everything is running smoothly.”

Cleaning System and Service

The Eco-Pro system consists of an air-operated cart that uses the Eco-Pro 360 chemical and can accommodate injection molds, blow molds, feed sections, Thermolators (TCUs), chill rolls and more.

The system is equipped with an air diaphragm pump, ensuring that every shop has accessible air and providing safety by allowing the system to pause during pressure builds, thereby avoiding downstream line ruptures. The key advantage of this chemical is its ability to be reused; some current users have been able to flush with the same chemical for up to five years, thanks to the built-in filtration feature of the cart.

Eco-Pro can also clean customers’ heat exchangers, enabling them to be reused instead of thrown away. Because the Eco-Pro flushing chemical is water-based, environmentally friendly, non-aerosol and nonflammable, it even removes and prevents rust by providing a protective nanocoating. It works on all metal surfaces without etching.

Notably, training operators on how to use the machine doesn’t take long. While there is some training involved, it's for a relatively simple machine and doesn’t require extensive time.

When consumables like filters and chemicals are required, Hinman and his customers can count on prompt customer service from iD Additives. “They pull up our information, and the product is usually on the truck the next day — sometimes on the same day, depending on how early they get the call.”

Rankine-Hinman performed a complete hose replacement about a year ago due to the amount of chemical they ran through it, and a package of hoses of the correct lengths arrived quickly. “We essentially got a new machine after replacing all the hoses,” Hinman says.

Ultimately, Eco-Pro has been a most welcome addition to the mold cleaning partnership between Rankine and its top-tier healthcare customer. “We’ve flushed two or three molds a week now,” Hinman adds. “We have a truck going back and forth to that customer and I know they can count on us and the chemical to service all of their molds.” Hinman believes that Rankine-Hinman will be expanding this operation soon, and anticipates an additional system to keep up with demand.