GW Plastics Bets on Metal 3D Printing for Conformal Cooling
An investment in a hybrid metal 3D printer is enabling moldmaker GW Plastics to produce better-performing molds with conformal cooling.
In response to growing demand in its global medical-device and drug-delivery business, precision custom molder GW Plastics has made a substantial investment in 3D metal printing at its Royalton, Vermont, captive moldmaking facility. The purpose is to build injection molds with conformal cooling for faster cycles.
GW is one of only a handful of precision mold builders that have invested in this technology. “We are in the precision molding business, and cycle time is paramount. We see it as in our best interest to lead the charge into 3D metal printing and conformal cooling,” says Timothy Holmes, vice president of engineering.
“That means faster cycles and better part quality through more predictable part shrinkage and warpage, so we won’t have to design molds with deliberate distortions to counteract shrink and warp.” he says. “Ultimately, that will mean faster time to market for our customers.”
GW Plastics has invested over $2 million in its Royalton mold facility over the last 12 months to support R&D and expand capacity. About half that amount went into a “hybrid” machine that both laser sinters metal powders and performs finish machining—“as good as any CNC,” Holmes says—as well as an environmentally enclosed room for the machine that has controlled humidity and protects the valuable metal powder—which is reused after every part build—from contamination.
“Our vision for metal 3D printing,” Holmes says, “is selective use of this technology for geometry-dependent conformal cooling.” GW Plastics previously used an outside supplier to produce 3D-printed metal mold components with conformal cooling, which it has tested for up to 100,000 cycles to establish their durability under injection molding pressures. Cycle-time savings with these test molds averaged 25-30 percent, according to Holmes.
Other advantages of 3D printing are parts consolidation in mold building. Optimizing cooling in conventionally machined molds, Holmes explains, can require assembly of multiple components using o-ring seals and special high-conductivity mold materials.
Metal 3D printing can eliminate all that. What’s more, Holmes points out, 3D printing eliminates drilling holes for cooling, ejectors, etc., which can be one of the more expensive operations in mold building.Holmes also notes that in the last five years he has seen a “vast improvement in steel selection for 3D printing,” including grades that provide a higher-quality finish than before. And more are coming, he adds, such as improved grades of stainless steel.
Despite all these advantages of metal 3D printing, Holmes states, “I wouldn't want to use it for everything.” Rather than “grow” entire cores and cavities from sintered metal powder, he targets the technology for inserts in critical areas. The reason, he says, is that metal 3D printing is “a little more expensive than conventional machining, but the payback is certainly worth it.”
One factor is the metal powders, which cost more than conventional mold steels. Another factor is the additional engineering analysis required—“a lot more flow and cooling analysis”—to design metal printed mold components. Although the time to “grow” the laser-sintered metal part and machine it to a rough finish is about the same as for conventional machining, Holmes notes, what adds time and cost are secondary operations on the printed metal parts, such as removing support structures. The net result is 20-25 percent additional manufacturing time for printed metal parts.
“We’ve only had the metal 3D printing machine for a few months, and this is still something of an R&D project,” Holmes says. There’s a lot to learn, such as being able to predict precisely the shrinkage and distortion of printed metal parts. Long-term durability in molding also has yet to be established, but Holmes is confident that printed metal parts will be able to hit the million-cycle benchmark. In any case, printed metal inserts can be replaced by growing new ones.
GW Plastics also recently purchased a 3D plastic printer. Although it is now used mainly to produce “show and tell” parts for product development, Holmes can foresee printing plastic cavities and cores to mold hundreds of parts for prototyping.
This article originally appeared on Plastics Technology’s website.
Related Content
In Casting and Molding, AM Simplifies Conventional Manufacturing
In new ways, additive processes are streamlining and enabling metal casting and plastic injection molding.
Read MoreDaimler, OMIC Evaluate Wire-Fed DED for Moldmaking
3D printing a core and cavity on machine from Gefertec, followed by machining, allowed for a complete mold tool to be produced in three days.
Read MoreIn "Hybrid" FIM Process, 3D Printing Complements Injection Molding
In a recent case study, Alpine Advanced Materials partnered with Nexa3D to produce 3D printed tooling for injection molded composites. Utilizing Nexa3D’s XiP desktop 3D printer and its Freeform Injection Molding process, Alpine was able to reduce prototype tooling production time and cost alike for its customers.
Read MoreThe Connector Conundrum: 3D Printed Mold Tooling’s Role in Innovation
ReelView Fishing faced an electronics obstacle in the development of its new technology for underwater video. Additive manufacturing for moldmaking allowed for the speed necessary to iterate to a solution. How inventors and invention will benefit from new ways of obtaining production-ready tooling.
Read MoreRead Next
How Avid Product Development Creates Efficiencies in High-Mix, Low-Volume Additive Manufacturing
Contract manufacturer Avid Product Development (a Lubrizol company) has developed strategies to streamline part production through 3D printing so its engineering team can focus on development, design, assembly and other services.
Read MorePostprocessing Steps and Costs for Metal 3D Printing
When your metal part is done 3D printing, you just pull it out of the machine and start using it, right? Not exactly.
Read More3MF File Format for Additive Manufacturing: More Than Geometry
The file format offers a less data-intensive way of recording part geometry, as well as details about build preparation, material, process and more.
Read More