In the Material Extrusion, plastic filament is fed through a heated extruding nozzle and deposited onto the build platform layer by layer.
Contents covered in this article
What is Material extrusion?
Material extrusion is an additive manufacturing technique that uses a continuous thermoplastic or composite material filament to construct 3D parts. The plastic filament is fed through an extruding nozzle, which is heated and then deposited onto the build platform layer by layer.
Material extrusion is now the most popular additive manufacturing process in terms of availability for general consumer demand and quality. As per ISO/ASTM 52900-2015, it is one of the 7 Additive manufacturing processes. You can read the other types here.
Material extrusion types
Material extrusion technology was first developed in the 1980s by S. Scott Crump under the registered name of fused deposition modeling (FDM). The term fused deposition modeling (FDM) and its abbreviation FDM are trademarked by Stratasys Inc, a company co-founded by Scott Crump.
A detailed description of fused deposition modeling can be found here.
Fused Deposition Modeling (FDM)
Fused filament fabrication (FFF) is another type that falls under this category developed by the members of the RepRap project, which is not restricted to use by others. You can read all about RepRap here. This is also referred to as Plastic Jet Printing.
The following video by Solid Concepts explicitly outlines the Material extrusion process.
Advantages and Disadvantages of material extrusion
Advantages
- Wide selection of print material
- Easily understandable printing technique
- Easy and user-friendly method of the material change
- Low initial and running costs
- Comparable faster print time for small and thin parts
- Printing tolerance of +/- 0.1 (+/- 0.005″)
- No supervision required
- Small equipment size compared to other AM
- Comparably low-temperature process
Disadvantages
- Visible layer lines
- The extrusion head must continue moving, or else the material bumps up
- Supports may be required
- Poor part strength along Z-axis (perpendicular to the build platform)
- Finer resolution and wider area increase print time.
- Susceptible to warping and other temperature fluctuation issues such as delamination
- Toxic print materials
Material extrusion materials
Although a variety of materials can be used in material extrusion, thermoplastics like acrylonitrile butadiene styrene (ABS), aliphatic polyamides (PA, also known as Nylon), high-impact polystyrene (HIPS), polylactic acid (PLA), and thermoplastic polyurethane are the most popular (TPU).
Lately, Material extrusion 3D printing successfully extrudes paste-like materials like ceramics, concrete, and chocolate, as well as plastic materials like polyether ether ketone (PEEK) and polyetherimide (PEI).
As long as the base thermoplastic material is present in sufficient quantities to ensure fusion between the layers, material extrusion can also be used with composite materials. This implies that components made of printed materials can contain components made of wood, metal, or even carbon fibre.