Mold Tools With PolyJet 3D Printing

Mold Tool 3D Print
Submarine with 3D printed components

Mold Tools with PolyJet 3D Printing

Cold Casting using VeroClear

Written By: Ian Nakamoto, Production Manager - Dec 18, 2020

International Submarine Engineering has been able to replace traditionally machined parts on their newest Explorer class AUVs with 3D printed parts from Forge Labs - reducing turnaround time on complex parts, lowering costs, and allowing more freedom of design.

“With 3d printing, we were able to produce the part for less money than traditional machining, shaved weeks off the delivery time, and were even able to print a second iteration when we discovered issues with the initial design.”

- International Submarine Engineering

3d printed mold for antenna

VeroClear mold designed for cold casting

Transparent 3D Printed Antenna Mold

In this instance, ISE needed to produce a mold for an antenna, which would traditionally be produced out of aluminum using CNC. 3D printing was selected as a cheaper, faster, and more flexible method to produce the part.

Accelerated Production

Cost in Polyjet


Traditional Cost


Lead Time

2 Days

Traditional Lead Time

2 Weeks

When compared to traditional manufacturing, 3D printing enabled a significant time and cost savings. Polyjet Matrix technology was selected for the smooth surface finish and rapid turnaround time - this large part took only 11 hours on the printer - as well as the wide range of materials available,  precise tolerances, and design freedom enabled by the soluble support.

3D Printing in Transparent Materials

Previously, the mold had been manufactured out of aluminum, which made it impossible to see inside the mold as the part was being cast. VeroClear, a transparent Polyjet material, was selected for the print, making it possible to monitor the resin for air bubbles as it was poured into the 3D printed mold. By being able to see this as it was cast, it made it possible to catch errors in manufacturing and correct them as it was being poured, reducing waste and improving part quality.

Using the mold for cold casting

The 3D printed mold in use

Precision 3D Printing

With process tolerances as tight as +/- 0.125 mm, and a layer height of just 28 microns, the Polyjet technology was a good fit for a part requiring an ultra-smooth interior surface surface finish - the 3D prints produced are typically suitable for casting without additional post-processing required. (By comparison, a process like FDM, even with our smallest nozzles and a 127 micron slice height, would require significant post-processing to achieve a comparable surface finish).

Soluble Support

Another advantage to printing with Polyjet was the unique soluble support material used to support overhangs. After printing, the soluble support material is washed away from the part using pressurized water. By printing with this soluble support material, it offered complete freedom of design, making it possible to focus on the hydrodynamic profile of the final result, without making compromises for ease of manufacturing. With no ‘A’ or ‘B’ surface to the part constraining orientation, the part could be oriented to minimize layer lines, and optimize strength, and the speed at which it was 3D printed.

This mold was used for cold-cast polyurethane parts, but 3D printed molds can also be used to enable the production of vacuum-cast and roto-molded parts, using Polyjet and Stereolithography (SLA) technologies.

Further Reading

Read more about how Forge Labs worked together with International Submarine Engineering and used 3D printing to replace traditionally machined parts here.

Read more about using another resin technology we offer - Stereolithography (SLA) - for 3D printed molds here. 3D printed molds produced in SLA also allow for transparent, high-resolution molds, with lower support costs than Polyjet.

Have a mold you’re looking to print, or optimize for 3D printing?

 Reach out to our team at and we can help.