When it comes to 3D printing, we are witnessing a huge wave of development, either in the 3D printing technology or in the use of innovative printing material. The process of producing 3D prints from various materials is generally called Additive Manufacturing (because the object is produced by adding a number of material layers until finish). In the past years, 3D printing has greatly evolved, featuring several new manufacturing techniques. Today, engineers and developers strive to improve 3D printing while making use of the latest technologies launched on the market. The current 3D printing technologies are:
- FDM Fused Deposition Modeling
- SLA Stereolithography
- 3DP – Tridimensional Inkjet Printing
- PJP Polyjet printing
- LOM Laminated Object Manufacturing
- DLP Digital Light Processing
- SLS Selective Laser Sintering
Whilst all the above technologies are still under development, each comes with its advantages and disadvantages. The most popular 3D printing method today in terms of affordability, use of technology and 3d print quality is FDM, or Fused Deposition Modeling.
What is FDM?
FDM is a simple, accessible and productive 3D printing technology used for new product development, prototypes and other manufacturing purposes. Since this is an ecological and easy-to-use technology, it is widely used in the transportation and food industry. (We discovered it long ago and have been using it ever since – or something like that)
How does it work?
Specialized software makes possible for the 3D model to be virtually sliced in transversal sections/ layers. The printing technology consists in inserting a plastic filament through an extruder that warms it until to melting. At this point, the melted filament is homogenously applied through extrusion, layer after layer, with high accuracy, in order to manufacture the 3D print according to the CAD pattern.
Types of plastics used for FDM production
The prime matter used for the FDM technology consists in plastic materials. However, we are not talking about just any kind of plastics. 3D printing requires a special type of material: thermoplastics. There are countless types of plastic materials used to produce filaments for 3d printing:
- PS (Polystyrene), as a thermoplastic material, can be melted at 100 Celsius degrees. At room temperature it features a glassy state. It can be successfully used for 3D molds with fine details. However, it degrades slow, creating environmental debates.
- BioFila Linen is a relatively new material used for creating 3D printing filament. This material doesn’t in fact contain any linen fibers, but Lignin, an organic material. The properties of BioFila are amazing. The 3D prints feature a texture similar to linen, yet stronger and more porous-looking like structure.
- PLA (Polylactic Acid) is a fairly strong material. However, it is less flexible than ABS. what’s interesting about PLA is that it’s biodegradable and will corrode in wet conditions. Since PLA is a resorbable composite, it is widely used in tissue engineering and maxillofacial surgery.
- PA (Polyamide) is used for producing some of the cheapest 3D printing filaments. PA is less brittle than PLA and ABS, thus much stronger. Additionally, it features self-lubricating properties, ideal for gears printing.
- PPSF (Polyphenylsulfone) is generally used in product development due to its high heat resistance. In addition, it is appreciated for the increased mechanical strength and resistance to solvents.
- PC (Polycarbonate) is ideal for complex 3D prints, such as fixtures, prototypes or composite works. It features a flexural and high tensile strength.
- ABS (Acrylonitrile Butadiene Styrene) is a material that delivers mechanical stability and resistance over time.
The last three types of plastic materials are the most commonly used for the production of industrial quality filaments. Filaments are an excellent prime matter for professional 3D printers. The better the filament quality, the better the 3D print results. Therefore, it is essential that thermoplastics used for the manufacturing of filaments should feature exceptional properties. The filament quality has a direct impact on the heat and mechanical resistance of the resulted prints. Therefore, PLA and ABS filaments are used to manufacture 3D prints for prototype testing. Read more about the differences of these two filaments here.
What are the properties of these materials?
Thermoplastics are heated, formed and finally cooled in infinite shapes. Such materials feature specific properties that make them indispensable for the 3D printing industry:
- Lightweight (density varies from .9 to 2 gm/cc).
- Resistant to various temperatures: from -100F up to an astonishing 600F.
- Thermal and electrical insulation.
- Adaptable chemistry can turn thermoplastics into objects similar to rubber consistency or as resistant as aluminum.
- Resistant to solvents at room temperature.
- Adding metal fibers or carbon to thermoplastics will confer electrical conductibility.
- Excellent replacements for metal objects, with significant weight savings.
- Resistant on long term and less prone to deformation, unlike metals.
- Engineering thermoplastics feature a tensile strength of over 7,500 psi.
Which industries rely on 3D printing and have undergone intense material research?
Although 3D printing is a relatively new industry, and there is still no mainstream production method, one thing is sure: the speed of development in the field is absolutely breathtaking. Some of the industries that already use 3D printing technology to improve and stimulate progress are:
- Aerospace industry
- Architecture industry
- Automotive industry
- Commercial products
- Defense industry
- Dental industry
- Consumer electronics
- Medical industry
- Mold industry
Considering the fact pace of current technologies, industrial techniques and equipment become obsolete very quickly. Whilst many companies are perfectly comfortable to using traditional production methods, many are foreseeing the future and opt for investing their resources to develop using a technology as simple and highly efficient as 3D printing.