‘Fuse Deposition Modeling’ (FDM) is a common
material extrusion process. This technique is
used to produce inexpensive, domestic and
hobby 3D printings. In FDM printers it uses a
thermoplastic filament which is heated to its
melting point. Pressure and the continuity of the
stream affect the final product quality. Thus, the
material should be added through the nozzle at
constant pressure and at a constant speed to
enable accurate results. FDM printers use two
kinds of materials. One is the modeling material
and the other one acts as a support material.
The most common printing material for FDM is
Acrylonitrile Butadiene Styrene (ABS) which is
used to make many consumer products and water-soluble wax or brittle thermoplastics like
Polyphenylsulfone (PPSF) are usually the supporting materials. Using thermoplastics is one of
the reasons which makes FDM popular because thermoplastics can endure heat, chemicals
and mechanical stress. In addition, FDM can print highly detailed and specialized objects,
therefore, FDM is commonly used by engineers.
Printing time depends on the size of the object being printed. Compared to other 3D printing
methods such as stereolithography (SLA) or Selective Laser Sintering (SLS), FDM is a slow
process. Once an object comes out of the printer, its support material is removed either by
soaking the object in water and detergent solution or by snapping the support material by
hand.
FDM is popular among companies spread in a variety of industries from automotive (BMW,
Hyundai etc.) to consumer good manufacturing where they have used FDM throughout their
product development, prototyping and manufacturing processes.
Professional FDM printers typically cost between $10,000 - $300,000 which makes them one
of the cheapest options for business investing in a complete 3D printing system.
Binder Jetting
This method was firstly invented by the Massachusetts Institute of Technology (MIT)
in 1993. In this method, it uses two materials; a powder-based material as the build material
and a liquid form material as the binder material. What happens here is, first, the powder
material is spread evenly over the build platform and the layer is flattened using a roller. Then
the binder material is deposited on the top of the flat powder material to print the first layer.
Then another layer of powdered material is spread over the first layer and again the binder
material is deposited. This process is repeated to produce the whole object.
This method is generally faster than others and can be further quickened by increasing
the number of print heads. Many mechanical properties of the final product can be changed
when the ratio of the two individual materials are changed. Therefore, this type of processes
suited for when the internal material structure needs to be specific quality. This allows colour
printing of products. Metals such as stainless steel, polymers like ABS and ceramics like glass
can be used as the build materials in Binder Jetting.
GAUGE Magazine University of Peradeniya
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