Why FDM 3D Printing is a Game-Changer for EPP/EPS Molding

If you’re still relying on traditional aluminium tooling for EPP and EPS molding, you could be spending more – and waiting longer – than necessary. FDM (Fused Deposition Modeling) 3D printing offers a smarter, faster, and more cost-effective way to produce high-performance molds that stand up to real-world steam molding conditions.

Proven Cost Savings

We recently compared the cost of an aluminium mold against a 3D printed mold made from ULTEM using FDM technology. The result? The aluminium version was 38% more expensive.

And that’s just the upfront savings. FDM tooling also slashes lead times, accelerates design iteration, and eliminates the need for expensive rework when designs change. For short runs, prototyping, or agile manufacturing, it’s a game-changer.

Built to Withstand the Heat

EPP (Expanded Polypropylene) and EPS (Expanded Polystyrene) are both molded using high-temperature steam processes, and FDM materials are engineered to handle it:

• ULTEM 1010: HDT 214°C (417°F)
• ULTEM 9085: HDT 177°C (350°F)
• PC: HDT 144°C (291°F)
• Nylon 12CF: HDT 168°C (334°F)

These high-performance thermoplastics are also naturally insulating, meaning heat remains concentrated in the mold rather than dispersing—making the steam cycle more efficient and reducing energy waste.

Smart Mold Design with Insight

With Stratasys Insight software, FDM molds can be precisely engineered to optimise thermal and mechanical performance:

• Mold cores printed with sparse internal structures to reduce weight and control heat flow
• Rear-facing mold layers printed with high porosity for effective steam venting
• Mold walls printed solid for structural strength
• Customisable layering of solid and porous regions to balance durability and thermal performance

This internal control allows you to tailor your molds like never before—something traditional tooling simply can’t match.

Print Details Others Can’t

One major advantage of FDM? You can directly print fine features that are either impossible or prohibitively expensive with traditional machining:

• Text, symbols, part numbers, and logos
• Surface textures for branding or enhanced functionality

No secondary machining. No added cost. These features are printed directly into the mold, ready to use.

Ready to Rethink Your Tooling?

If your mold tooling is slowing you down—or eating into your budget—now’s the time to consider additive manufacturing. With FDM 3D printed molds, you get:

• Faster lead times
• Lower costs
• Greater design freedom
• Thermally efficient, high-temperature-ready performance

The Stratasys Fortus 900 is the ideal printer for this application, offering the large build size, precision, and material compatibility needed for high-performance molds. With its ability to print in tough, high-temperature materials like ULTEM and Nylon 12CF, the Fortus 900 is purpose-built to handle the demanding conditions of EPP and EPS molding, giving you the reliability and quality required for production-grade tooling.

It’s a smarter way to mold EPP and EPS parts—and it’s ready when you are.

Contact us today to discuss your project.