Material extrusion offers a range of advantages, as follows:
- Low set-up and running costs
- Wide selection of printing materials available
- Easy to learn and user-friendly
- Able to produce parts with a printing tolerance of +/- 0.1 (+/- 0.005″)
- Comparably fast print time for thin or small parts
- Low temperature process
- Equipment is small sized and able to be used in the home
- No supervision required
Despite the many advantages, there are also a number of disadvantages associated with the material extrusion process, as follows:
- Print materials are toxic
- Process can leave visible layer lines
- Creating finer resolution parts or depositing over a wide print area can dramatically increase printing time
- The extrusion head must remain in motion to prevent the deposited material from bumping up
- May require support material for some structures
- Parts are susceptible to warping, delamination and other temperature fluctuation-related problems
- Tends towards poor part strength along the vertical Z-axis.
Materials extrusion is used across commercial, research and hobbyist sectors due to its low complexity, ease of implementation and compatibility with commercially-available materials. Applications include the creation of functional engineering prototypes and systems, including for clinical uses.
Examples of material extrusion technology include composite filament fabrication (CFF), fused filament fabrication (FFF) and fused deposition modelling (FDM).
Similar to other 3D Printing processes, material extrusion involves drawing material through a nozzle where it is heated and deposited layer by layer. The nozzle is able to move horizontally along a platform, which moves up and down as each layer is deposited. In order to achieve accurate results, the extruded material needs to be fed through the nozzle as a steady stream under constant pressure.
With CFF, two print head nozzles are used at once, with one following the usual material extrusion process to create the outer shell and internal matrix of the part, while the other deposits a continuous strand of composite fibre inside the printed parts to add strength. This can create parts with a strength comparable to metal.
Material extrusion is commonly used on inexpensive domestic and hobby 3D printers, although it is also found in more industrial settings, such as for constructing buildings through concrete extrusion or for making human tissues and organs for the medical profession.
What is material extrusion used for?
Material extrusion additive manufacturing technology involves feeding a continuous filament of thermoplastic or composite material through an extruding nozzle to construct 3D parts.
The plastic filament is heated and deposited onto a build platform in layers, with material extrusion being commonly used in domestic, manufacturing and industrial settings where it is used to create non-functional prototypes and cost-effective rapid prototyping for iterations of a product.
What materials are used in material extrusion?
Material extrusion can accommodate the use of a range of materials, with the most popular being thermoplastics like acrylonitrile butadiene styrene (ABS), aliphatic polyamides (PA, aka Nylon), high-impact polystyrene (HIPS), polylactic acid (PLA), and thermoplastic polyurethane (TPU).
More recently, plastic materials such as polyether ether ketone (PEEK) and polyetherimide (PEI) as well as paste-like materials including ceramics, concrete and chocolate have been successfully extruded using this technique.
Material extrusion can also be used with composite materials so long as the base, thermoplastic material is present in sufficient quantities to guarantee fusion between the layers. This means that materials such as wood, metal and even carbon fibre can be included in the printed parts.
Material extrusion is a commonly-used additive manufacturing (or 3D printing) technique that is used both domestically by hobbyists and in industrial settings. Able to deposit a range of materials to build 3D parts, it works by laying down individual layers of material through a heated nozzle (or nozzles) onto a build platform.
Although other additive manufacturing techniques are faster in producing larger objects and also offer a higher level of quality than material extrusion, this technique is still widely used for prototyping due to its ease of use and the relatively inexpensive set-up and operating costs.
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