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In one sense, the addition of 3D printing to KraussMaffei’s (Brighton, Mich., U.S. and Parsdorg, Germany) technology portfolio is a natural extension of the company’s specialty in plastics processing equipment. Its large-format additive manufacturing (LFAM) PowerPrint Flex robot-based extrusion 3D printer and PowerPrint Plus gantry-style system complement existing product lines for injection molding, extrusion and reactionary processing. Additive manufacturing is now one of multiple equipment types available to customers for making polymer-based parts.

However, there’s another factor at work behind KraussMaffei’s 6-plus years in developing its 3D printing technology: significant internal applications.

“We would have a use case for this technology even if we weren’t selling the machines,” says Dan Rozelman, technical and application sales manager.

At KraussMaffei’s production facility in Brighton, Michigan, this point is evident (read “KraussMaffei expands composites, plastics capabilities...”). The building functions as a factory for machine assembly, a showroom of technology, a test bed for new customer machines before they are shipped out — and also, a manufacturing facility for tooling.

Large prototype or end-use molds, trimming fixtures, router tools, risers and other tool components are now 3D printed using KraussMaffei’s own additive technology, providing myriad benefits to both the manufacturer and its customers, the ultimate users of these tools.

Plastics processing, reconfigured

Founded in Germany in 1838, KraussMaffei has a long history in manufacturing technology and is well-known in the plastics processing industry. Its Michigan location supports the sale of equipment and tooling for foam-in-place, laminating, edge folding, trimming and scoring processes, all common in development and production of automotive interiors. But the company’s broad expertise in plastic forming and processing worldwide made it relatively easy to step into additive manufacturing.

“We know how to melt and control plastic,” Rozelman says. “We have the controls, the heating, the automation, the extruders. At a basic level, we rearranged those components to make our 3D printers.”

Indeed, the company’s pellet-fed 3D printers work much like a more conventional extrusion line. The gantry-style PowerPrint Plus even uses the same linear drives found in its injection molding machines. But there are some differences in the equipment, like additional heat zones for the 3D printing extruder that wouldn’t be necessary for other processes.

The way that the company interacts with material suppliers has changed as well for additive manufacturing, with more frequent collaboration with pellet manufacturers to develop AM-specific formulations and qualify their materials for the process.

The two 3D printing products are similar in that they offer nozzles ranging from 2 to 20 millimeters; can deposit several grams per second up to 75 kilograms of material an hour out of a single extruder; and have the capability to run lights-out with cameras and the company’s Data Explorer tool capturing data along the way. Both machines print onto reusable build plates on a 16-zone vacuum table which can be heated up to 60°C. 

The primary differences are work envelope size and shape, as well as print environment. The enclosed PowerPrint Plus gantry machine has a 2 × 2.5 × 2-meter build envelope, with a chamber that can be heated to 180°C. The PowerPrint Flex, built on a Comau robot, prints in an open environment which enables multiplanar printing and a larger potential build volume. 

Applications for LFAM

The Michigan facility offers print-on-demand and manufacturing services in other processes for customers up to a point, but the company does not wish to be a service bureau. The production that happens in Brighton is primarily prototypes and “pre-run” parts, to help customers assess equipment before a purchase or to “get them over the hump” with bridge production of parts while equipment is being installed.

While 3D printing of these early production run parts isn’t common, KraussMaffei is increasingly applying its LFAM technology to produce prototypes before tooling is created, enabling customers to be absolutely sure of the design before embarking on the expensive step of tool production.

In addition to selling machines, KraussMaffei also assists customers with development and production of the tooling — and this is where it has found the most critical use cases for LFAM.

Tooling for the processes that KraussMaffei customers most commonly require is typically machined from metal, often from large castings. Tooling or its components are often sourced from overseas, adding lead time to an already lengthy and expensive process.

An example of a 3D printed trimming tool (in orange) that could be used within a KraussMaffei machine to hold a formed automotive part for this process. Seen at Formnext 2024. 

Offering polymer LFAM as an alternative to metal tooling has enabled the company to dramatically reduce lead times, which often gives the additive tool an edge. For scoring and router fixtures, for example, the company has realized significant time savings with 3D printing versus machining that make this solution compelling. Often, the 3D printed solution offers cost savings as well. 

An alternative to casting for risers

But there are many other benefits to be realized through 3D printed tooling, too. One killer application that the company has found is a common component of large tools called the riser. The riser does not form geometry directly, but holds the mold and supports instrumentation required in its operation. Risers are typically cast and machined aluminum, but at KraussMaffei they are now commonly being 3D printed from polymer composite.

The application arose first out of necessity. A customer had a tool that was being made in China that was held up in shipping; in order to develop the rest of the system around that tool, KraussMaffei 3D printed a riser primarily as a prototype. The company has since found that 3D printed risers printed from carbon fiber-filled polycarbonate (PC) or glass-filled PETG perform as well as, and actually better, than aluminum tooling.

The risers seen in the foam-in-place tool below are an example — one for each half of the mold. Each riser was 3D printed in about 8 hours using carbon fiber-reinforced polycarbonate, and then finish machined.

“The time to machine these risers is about the same as it would be to machine an aluminum casting,” Rozelman says, “but the material cost is about 30% less, and there is a 40% weight savings over the aluminum tooling.”

Overall production time is about 1 week for a 3D printed riser, versus 10 weeks for a machined casting. The speed comes from the change in process as well as where the riser is produced.

“This is vertical integration of a process we wouldn’t typically do,” says Chad Randolph, project manager, referring to riser production.

“What we used to buy, we now make,” Rozelman adds.

Improved tool performance, sustainability

But the greatest benefit of the 3D printed risers might be in their impact on tool operation. Aluminum conducts and dissipates heat well, which is sometimes desirable — but for a foam-in-place tool that must be kept within an ideal temperature range during operation, this is a challenge. Heaters must run constantly to maintain the temperature in the tool even as the aluminum structure works to remove it.

Polymer composite, however, is an insulator. KraussMaffei has found that in use, tools with 3D printed polymer composite risers keep more of the heat in the tool, preserving its temperature while also protecting the press from excess heat.

In addition, the risers’ lighter weight reduces stress on the machine motor and brakes. KraussMaffei estimates energy savings up to one-third over the tool’s lifetime, likely 5 years in production and 5 years in service, or more.

“The energy savings alone makes this a better solution,” Rozelman says.

Such tools mainly see compressive forces (typically 20 to 30 tons of downward force in use). Printed risers offer a compressive strength between 9,000 and 12,000 psi, which is more than enough to support this tonnage. In addition, the lighter weight of the polymer riser makes it possible to support the tool over a larger area, which reduces flexural stresses on the tool. 

There is another benefit to 3D printed tool risers that KraussMaffei sees over the long term: material sustainability.

“Today the price of billet aluminum is $2 to $7 a pound, depending on grade. We cost it out at $5 a pound,” Randolph says. But a significant amount of the aluminum purchased for a riser is never used, and loses its value. “Scrap price for aluminum chips is just under $1 a pound,” he says.

LFAM enables KraussMaffei to use less material from the get-go, saving material cost, and produce less waste. Additionally, the material is directly recyclable; according to the company, it’s possible to grind up old or unneeded fixtures and throw the flake right back into the printer, creating a circular economy for LFAM polymer composite parts.

Originally published on sister brand, .