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Conformal cooling is one of additive manufacturing’s well-known applications, where the technology’s geometric capabilities can enable the precise placement of cooling channels throughout an injection mold. But while reduced cycle times and improved part quality resulting from cooling advances were once the primary reason that AM made its way into moldmaking, 3D printing is now also being used to make molds for different reasons — including cost, lead time and feature complexity as I saw at this year’s .

PTXPO 2025 brought together plastics professionals in molding and moldmaking for three days of exhibits and talks in Rosemont, Illinois. While the event primarily focuses on plastics molding technology (I found no 3D printers on the show floor, but plenty of injection mold presses), additive manufacturing’s influence could be seen through numerous examples of 3D printed tools.

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Here are five trends in 3D printed injection mold tooling in evidence at the show:

1. Ceramic Resin Molds 

Both Nota3D and Impac Systems Engineering, two equipment distributors covering different regions of the U.S., were showing tools made on the Axtra3D Hybrid PhotoSynthesis (HPS) technology platform. This combines the speed of projector-based area curing with the precision of a laser for fine detail.

Axtra3D’s TruLayer technology (consisting of a dual gantry for build plate stability and a specialized membrane system with a sliding window that prevents shear forces from deforming layers) makes it uniquely capable of printing bulky components from , a 65% ceramic-filled resin supplied by BASF. This material requires UV curing but not post-print heat treatment, making it possible to produce a viable injection mold capable of supporting up to 1,000 shots in as little as half a day. Ceramic molds made this way are affordable (one on display cost just $80 in material) and can support molding of high-performance resins including Delrin, polypropylene, polycarbonate, TPU, silicone, and electrostatic dissipative (ESD) and flame-retardant polymers.

2. 3D Printed Porosity for Venting

When hot plastic is injected into a mold, the displaced gases need an outlet to exit the tool, often accomplished by incorporating slots or porous areas that allow gas to escape but not plastic. While porous metals are available as billet to be machined into mold components for venting purposes, laser powder bed fusion (LPBF) makes it possible to more easily build porosity directly into the tool where necessary.

Additive tooling and part producer Next Chapter Manufacturing showcased multiple examples of applied porosity including (which allow molders to take advantage of porous venting without retrofitting existing molds) as well as custom molds with specified porous areas, often used in conjunction with conformal cooling for faster cycle times and reduced deformation.

This 3D printed sample made by Zero Tolerance demonstrates how the company has been able to produce porous regions with its Xact Metal LPBF printer. . Source: Additive Manufacturing Media

In the booth of 3D printer supplier Xact Metal , customer Zero Tolerance showcased a porous sample made from Uddeholm Corrax, a corrosion-resistant tool steel well suited to routine cleaning as well as long-term mold use. According to Xact, porosity can be tuned between 68-92% with print parameters, resulting in pores between 10 and 20 microns that allow for venting without drawing in the molded material.

3. Steels Beyond Maraging

Maraging steel is relatively easy to 3D print as a metal powder, which has made it a go-to material for producing mold tooling. However, maraging steel has suboptimal properties for this application. The material is prone to corrosion, making one of additive manufacturing’s best benefits for molds — conformal cooling — problematic because water used in cooling lines can cause rust and buildup inside the tool. Corrosion resistant tool steels are therefore a better choice for mold inserts with internal channels, another benefit of the Corrax material showcased by Xact Metal. 

Material supplier International Mold Steel (IMS) also highlighted HTC-45, a tool steel powder produced by Daido Steel that it distributes for LBPF of molds. The HTC-45 tool steel (an optimized version of H-13) provides superior thermal conductivity (about 36 watts per meter-kelvin) compared to maraging. HTC can be used in combination with cooling features, but enables molders to more frequently “Let the steel do the work,” for heat transfer, says sales representative Adam Barker.

4. 3D Printing As a Lead Time Advantage

While additive manufacturing found its footing in injection molding through geometric capabilities to support conformal cooling, it is now more frequently an option because of its speed or the chance to skip steps in mold manufacturing. Nota3D has observed customers adopting the ceramic mold solution outlined above to produce multiple design iterations in a shorter span of time than just one could be made conventionally, as well as to onshore mold development or even some part production in light of tariff concerns.

3D printer manufacturer Mantle  during PTXPO that enable 20% faster mold production with a higher deposition rate for noncritical surfaces such as outer edges (which are often ground to fit and therefore more tolerant of variation in printing). The company’s paste-based printing process is already adept at producing mold tools with very deep features, enabling moldmakers to skip sinker EDM and the necessary tool-up process this operation would entail.

5. 3D Printing As an Alternative (and Support) to Conventional Mold Production

Another update from Mantle included improved capability to produce flared walls and overhangs in 3D printed molds using a dovetail cutter in sequence with the metal deposition — an advance that will enable customers to use the solution for more tooling types as an alternative to machining of multiple mold components.

But moldmakers are also gleaning additive’s benefits even when AM accounts for just a small portion of the final tool. Alba Enterprises showcased a mold designed by mechanical engineering students at the University of Puerto Rico featuring a “hybrid” base combining machined stainless steel with laser powder bed fusion of complex features printed right on top using the OPM platform from Sodick — leveraging AM only for the most complex aspects of the tool and more affordable machining for the rest.

About the Author

Stephanie Hendrixson reports on 3D printing technology and applications as executive editor for . She is also co-host of , a video series that highlights unique, unusual and weird 3D printed parts, and co-host and creator of the .