Flame Retardant Plastic Materials for Additive Manufacturing

In critical applications, fire safety is non-negotiable—and 3D printing is rising to the challenge. In recent years, we’ve seen a surge in fire- and flame-retardant materials tailored for additive manufacturing, available as filaments, resins and powders. These materials are designed to resist ignition and slow the spread of flames, making them essential in high-risk or highly regulated environments. As the demand for safer, high-performance parts grows, so does the range of flame-retardant plastics adapted for 3D printing. But what exactly sets these materials apart? And where are they making the biggest impact?

Properties of Flame Retardant Materials Used in 3D Printing

First of all, it’s important to distinguish between fire-retardant and flame-retardant materials, because although the difference is subtle, it does exist. Fire-retardant materials are permanently resistant to fire, either because of their intrinsic properties or because of the way they are manufactured. Conversely, flame retardants owe their ability to slow the spread of fire to specific chemical treatments. Some are self-extinguishing, but their effectiveness depends on the coating applied. In both cases, these materials share common characteristics: they are low-flammability, emit little smoke and toxic gases, and offer controlled or reduced combustion when exposed to flames.

ULTEM 9085 is one of the high-performance, flame-retardant materials used in 3D printing.

In additive manufacturing, both types of materials are used, whether they are in the form of resins, filaments or polymer powders. These materials are categorized and certified as flame-resistant through specific tests. Specifically, plastics are tested according to UL94 regulations, an international standard developed by Underwriters Laboratories (UL) to classify the behavior of plastic materials exposed to a flame. In detail, UL94 involves testing a material according to several variables, including Horizontal Burning (HB), which is used to test whether the material burns slowly in a horizontal position, and Vertical Burning, which tests the material in a vertical position. The latter can have three grades of certification (V-0, V-1, V-2) depending on how the materials respond to the tests. The V-0 certification is the best, and it is the one that many flame-retardant or fire-retardant 3D printing materials have obtained. The main feature of UL94 V0-certified materials is that, when exposed to flames, they stop burning within 10 seconds without a fiery drip.