Four years ago, Ben Ismert began a mission to double the size of the global rotational molding industry over the next 30 years. While Ismert hasn't hit that target yet, the founder and president of Ripple Engineering LLC is making progress.
With Ripple Engineering, Ismert has been chipping away at that goal with what the Kansas City, Mo.-based machinery startup calls "pressure-cooled rotomolding," a process that boasts shorter cycle times, improved impact strength and reduced warping compared with traditional rotomolding.
The controlled cooling cycle enables predictable and controllable shrinkage, he said.
"Cooling is where you get all of your advantages," Ismert said in a phone interview. "It's where you get your warp control. You get higher impact strength and the reduced cycle time, which, yes, it's the shortest part of the cycle."
But the key to all of those benefits, Ismert said, is that the internal vent opens automatically during the cooling cycle to circulate high-volume chilled air throughout the interior of a newly formed part.
On current models of the Ripple Engineering machine — now available in three standard sizes — the oven and mold rotate together. The machine also uses active venting technology, where it automatically equalizes the pressure between the inside of the part and the surrounding atmosphere during the heating stage. This eliminates the potential for blow holes and thin spots at parting lines and removable inserts.
The active vent can also be programmed to hold a specific pressure inside the part during the heating cycle after a layer of material forms on the inside surface of a mold, which can reach a maximum temperature of 650° F. This can improve a part's surface aesthetics and potentially improve its strength characteristics, Ismert said.
It also opens up the possibility for molding engineered resins beyond polyethylene.
At Ripple Engineering's 10,000-square-foot facility, the company is testing the ability to mold additional materials such as polycarbonate, acetal, polypropylene, nylon and others.
"We're molding those in our shop on our prototype machine for some of those resin distributors or resin manufacturers in hopes to connect them with potential new markets — a new market of rotational molding vs. only doing extrusion or injection molding," Ismert said.
"Polyethylene is fun, but I really want to introduce new materials into the rotational molding industry to expand it," he added.
That's a longer-term venture for Ripple Engineering, but all of these combined attributes are designed to underscore the company's motto of shaping the perfect part every time.
"We've shown that we can create an environment that's controllable, that can mold engineered materials, and we've simplified it enough where anyone can do it," Ismert said.