Automated Fiber Placement (AFP) is the additive manufacturing process of creating 3D shapes using composite layers of heated resin, which also contains non-metallic fibers. This process can result in 3D printed parts that are two times stronger than steel at one-fifth of the weight (which is excellent); however, the technology traditionally requires million-dollar AFP systems (which is not great). Desktop Metal has recently launched its new Fiber™ platform, which utilizes a technology they call “micro” automated fiber placement (μAFP), that radically reduces the structure and cost of the typical AFP process .
“This new print technology finally brings the material properties of AFP composites to small parts under twenty pounds, which would typically require expensive tooling, extensive manual labor, multiple consumables and multi-step, long process cycles,” said Dr. Konstantine Fetfatsidis, Vice President of Composite Products for Desktop Metal.
Getting to Know the Base Materials
First, it is essential to understand that base materials are “mixed” to create these composite materials. Almost all the materials used in this process are a blend of fiber elements, for example, carbon fiber or fiberglass and a polymer such as nylon, PEEK or PEKK. The Fiber platform allows for the blending of these materials in a machine that is small enough and safe enough to use in an office setting.
Widely used 3D printed materials like ABS and PLA only account for a small fraction of what an engineering project typically needs. Continuous fibers benefit from the high specific stiffness of carbon or fiberglass by carrying loads across their full length, which enables the creation of stronger and more light-weight 3D printed components. When using the Fiber μAFP process, you can achieve results over seventy-five times stiffer and over sixty times stronger than ABS alone.
|Data provided by Desktop Metal|
Chopped Fiber Filament
Chopped fiber filaments are made by adding discontinuous fibers (typically less than 6 mm in length) to a thermoplastic base. These materials are used during the Fused Filament Fabrication (FFF) printing process to provide dimensional stability and enhanced mechanical and thermal properties when compared to standard thermoplastics.
|Data provided by Desktop Metal|
Combining Continuous Fiber with Chopped Fiber Filaments
Fiber printers utilize a dual-deposition print process to create these composite material parts. During the μAFP process, one Fiber print head deposits a continuous fiber tape to build reinforced sections while a second print head extrudes chopped fiber filament to build an exterior shell. The use of both material types in tandem allows for the maximum benefit of the AFP/ μAFP process. Continuous fibers take advantage of the high specific stiffness of carbon or fiberglass by carrying loads across their full length. When bundled together, continuous fibers create tows with high fiber volume fractions (up to 60%).
3D printed composite parts can be indispensable for manufacturers when prototyping or for critical end-use parts that require high stiffness and fast lead times over machined components. Key uses can benefit a wide variety of industries, from manufacturing, tooling and automotive to consumer electronics, sporting goods, medical, education/research and more.
- Jigs and fixtures, including robotic end effectors, CNC soft jaws, laser etching fixtures for medical tools, Electrostatic Discharge (ESD) and fixtures for manufacturing;
- End-use parts, including automotive, electronics, consumer goods such as racing bicycles, marine, aviation or machine design; and
- Components where light-weighting is critical for performance, such as wheelchairs and sports racing equipment.
3D printing technologies have advanced rapidly over the years, and with new innovations, they are becoming more accessible, user-friendly and adoptable, making the 3D printing process easier than it used to be.