fused deposition modeling

fused deposition modeling
Name	Fused Deposition Modeling
Caption	A typical FDM 3D printer in operation.
Other names	Fused Filament Fabrication (FFF)
Inventor	S. Scott Crump
Invention date	1988
Company	Stratasys
Classification	Additive manufacturing
Material	Thermoplastics, composites

fused deposition modeling is a core additive manufacturing technology where a thermoplastic filament is heated, extruded, and deposited layer-by-layer to build a three-dimensional object. The technique, also widely known as Fused Filament Fabrication (FFF), was commercialized by Stratasys and has become synonymous with desktop 3D printing. It is distinguished by its use of a moving print head and a wide range of available materials, making it a foundational process in both rapid prototyping and direct digital manufacturing.

Overview

The fundamental principle involves feeding a solid filament of material through a heated extruder assembly, melting it, and precisely depositing the molten polymer onto a build platform. The process is controlled by G-code instructions typically generated from a 3D CAD model sliced into thin layers by specialized software. As one of the most accessible forms of additive manufacturing, it is utilized extensively by industries ranging from aerospace to consumer electronics, as well as in educational settings like MIT and hobbyist communities worldwide. The technology's versatility is further demonstrated by its adaptation in open-source projects such as the RepRap Project, which spurred the proliferation of affordable desktop printers.

Process

The process begins with the creation of a digital model, often designed in software like SolidWorks or Autodesk Fusion 360, which is then converted into an STL (file format) file. Slicing software, such as Ultimaker Cura or PrusaSlicer, processes this file to generate the toolpath instructions for the printer. During printing, the filament, typically supplied on a spool, is pushed by a drive gear into the hot end, where it is melted. The molten material is extruded through a nozzle onto the build plate, with the print head or plate moving along the X, Y, and Z axes to form each cross-sectional layer. Support structures, often made from a dissolvable material like PVA, are generated for overhanging features and removed post-processing.

Materials

A wide variety of thermoplastic polymers are used, with polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) being the most common due to their ease of printing and mechanical properties. Engineering-grade materials include polycarbonate (PC), known for its strength, and polyamide (Nylon), valued for its durability and flexibility. Composite filaments infused with materials like carbon fiber, fiberglass, or metal particles are produced by companies such as Markforged to enhance strength and thermal properties. Specialized materials also encompass thermoplastic polyurethane (TPU) for elastic parts and high-temperature resins like polyether ether ketone (PEEK), used in demanding applications within the NASA and European Space Agency.

Applications

Applications span from rapid prototyping of conceptual models and functional parts for companies like Ford and Boeing to tooling, jigs, and fixtures on factory floors. In the medical field, it is used to create anatomical models for surgical planning at institutions like the Cleveland Clinic and custom prosthetics. The automotive industry employs it for lightweight components and custom interior parts. Consumer applications include custom enclosures, artistic sculptures, and educational kits distributed by organizations like the National Science Foundation. The technology has also been pivotal in distributed manufacturing during crises, such as producing PPE during the COVID-19 pandemic.

Advantages and limitations

Primary advantages include a relatively low cost for both machines and materials, a broad material selection, and simplicity of operation that enables widespread adoption in settings like TechShop and university labs. The process is generally safe, requiring no lasers or reactive chemicals, and allows for complex geometries unachievable with subtractive manufacturing. However, limitations include anisotropic mechanical properties due to layer adhesion, visible layer lines requiring post-processing, and generally slower build speeds compared to technologies like selective laser sintering. Dimensional accuracy can be affected by factors like warping and nozzle size, and the strength of parts is typically lower than those produced by injection molding.

History

The technology was invented in 1988 by S. Scott Crump, co-founder of Stratasys, who filed the key patent and coined the term Fused Deposition Modeling. Stratasys commercialized the first FDM machine in the early 1990s, holding the foundational patents until their expiration around 2009. This expiration catalyzed the open-source 3D printing movement, notably with the launch of the RepRap Project by Adrian Bowyer at the University of Bath, which designed a self-replicating printer. The subsequent proliferation of low-cost FFF printers was driven by companies like MakerBot Industries, founded by Bre Pettis, and Ultimaker, fundamentally democratizing access to the technology and fueling innovation across global maker spaces.

Category:Additive manufacturing Category:3D printing processes