3D printing and injection molding: charting the best of both worlds | Plastic Today

2021-11-10 03:13:06 By : Mr. Gary Dong

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Industrial 3D printing company Essentium's acquisition of Collider and its Orchid printer technology, and the patent for 3D printing molds of the University of North Florida (UNF) professor Steve Stagon raises the standard for optimizing production while seeking to reduce or eliminate costly tools. Greater execution Bulk parts.

After acquiring Collider's technology, Essentium is firmly committed to the realization of programmable tools through digital light processing (DLP), which can print a thin soluble photopolymer shell in the same build room and fill it with traditional thermoset polymers .

"We believe that programmable tools and other components of our Orchid platform will help drive the polymer-based Additive 2.0 revolution," said Graham Bredemeyer, director of Essentium photopolymers in Pflugerville, Texas. The technology produces "parts that mimic the strength and surface quality of traditional techniques such as injection molding and CNC machining-but in a short time." 

In terms of production goals, Essentium is more willing to “consider the activities of the machine group required to produce 50 to 1,000 or more parts per day,” Bredemeyer added. "We think this will shorten the development and mass production time for our customers by months or even years, especially in the medical, military and transportation sectors."

Bredemeyer explained that this best of both worlds approach takes advantage of the core advantages of 3D printing and molding.

"The parts produced by the DLP direct printing process are as good as the resins used. Today, photosensitive resins are not as strong as the off-the-shelf materials used for injection molding or CNC machined parts. Collider technology uses a wider range of thermoset polymers as the basis for the finished part, so Will not be subject to these restrictions."

At the same time, Stagon’s patent for printing injection molds with optimized coatings and cooling channels aimed at an idea that "quite a lot of teams have studied", he said-to produce polymer molds whose performance matches as much as possible with metal molds to save Time and money.

Professor Jacksonville said that Stagon's molds are aimed at small and medium batches and parts series with slightly different geometric shapes. "In this field, traditional molds are not cost-effective-too much capital investment in small batches." But attempts to print polymer molds encountered several problems:

Professor UNF's solution? Create a process that preserves surface features "over a few parts and increases the thermal conductivity close to a point, thereby reducing the adjustment of injection parameters. In high-run production, the metal mold is still and will always be the king. Our work enables small batches It’s closer to the aluminum mold and makes the workflow faster and reduces adjustments."

For the coating of the mold, Stagon draws on the technology of traditional molds.

"We combine electroless plating and vapor deposition or'sputtering', first'impact' the mold surface to make it conductive. Then we plate 1 to 50 microns of eNi, NiP or CoP. This provides us with a A very strong layer that can conduct heat well. On top of this, we added classic mold coatings, such as PTFE Ni and electroless nickel boron. By making the surface smooth and having good lubricity and release properties, we can Retain thick structural coatings for longer and reduce the adhesion between the polymer and the coating."

At the same time, 3D printing allows Stagon to place the cooling channels close to the features and position them relative to the internal mold features. "With the strength of the surface metal coating, in some cases, when the injection pressure is kept low, we can reduce the thickness to one centimeter or less. We are working hard to obtain good temperature profile data for this, but in the early In the prototype, we found that the cooling time has been reduced by a factor of two."

Although the pandemic has slowed development, Stagon is eager to establish a partnership to develop and test the technology outside the laboratory. "Our entry point is expected to be in the field of traditional parts and molds." If you are interested in considering a partnership, please send an email to Stagon.

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