Markforged shook the 3D printing world when, two years ago, the company first announced its technology, capable of feeding continuous strands of fiber reinforcement material into objects as they are 3D-printed. Since then, Markforged has continued to improve its continuous filament fabrication (CFF) process and expand the materials with which it reinforces 3D-printed parts. The latest development from the company is a new filament dubbed Onyx.
CFF functions by combining a base material with reinforced fibers to create strong, lightweight parts at a reduced cost. Through one nozzle, continuous strands of carbon fiber, fiberglass, Kevlar or high temperature, high strength fiberglass are fed onto the print bed as a second nozzle lays down the base material. In the past, that base material has been a basic nylon filament. Now, however, there’s Onyx.
Onyx is composite filament made up of nylon and chopped carbon fiber, allowing for the combined strength of both materials. While the carbon fiber makes Onyx 3.5 times stiffer than the company’s standard nylon, the nylon is meant to make the material tough and wear resistant as well. Onyx also has a heat deflection temperature of 145 °C.
Markforged also claims that Onyx has improved dimensional stability so that it doesn’t warp due to the decrease of thermal deformation and increase of heat dissipation when the material is printed. This, the company suggests, allows for larger, steeper overhangs without dripping and sharper edges, as well as parts that more closely resemble the CAD models.
The aesthetic qualities of the material subsequently contribute to an overall improved appearance when compared to nylon parts, as well as reduced post-processing, according to Markforged. The translucent nature of the nylon made the inner reinforcement material more visible to onlookers, but Onyx has a matte black appearance so that it can be used for more consumer-facing parts.
By combining CFF with chopped carbon fiber filament, the company is able to further increase the strength of its materials. Parts 3D printed with the CFF process, however, may not be as complex as objects 3D printed without continuous fiber reinforcement, meaning that there is some trade-off between part complexity and strength. Nevertheless, CFF is the only desktop technology that allows users to fabricate parts with true carbon fiber reinforcement and may be perfect for replacing CNC milling.
Next, Markforged will have to work to blow its machine up to 100 times the size so that it can compete with the new large-scale fiber composite 3D printer from EnvisionTEC. Until then, sample parts made from Onyx can be purchased here or potential customers can see if their local Markforged 3D Hub has Onyx in stock.
It should be noted that Onyx is meant to work only with the Enterprise version of the Mark Two 3D printer. Those who don’t own this powerful machine may want to look to the carbon fiber-reinforced nylon from 3DXTech.