What is 3D Printing?
How does it work? What is it for?
3D printing or Additive Manufacturing is a group of technologies that are changing the whole manufacturing industry.
It was born in the 1980s and is a technology for the production of objects. The material to create the parts is deposited, melted, or bonded, typically layer by layer. The most commonly used materials for 3D printing are plastic and metal, but you can pretty much print anything suitable to be deposited in layers of materials, from concrete to organic matter.
Until about 2015, different types of 3D printing technologies were only considered suitable for the production of functional or aesthetic prototypes.
Objects made with 3D printers today are better in terms of how well they work and how much they cost. This means that 3D printers are being used more and more in factories to make not only rapid prototyping but also thousands of final items.
WHAT ARE THE 4 MAIN ADVANTAGES OF 3D PRINTING?
It has the versatility of being a rapid production process of both prototypes and pieces in large series and allows the creation of complex geometries otherwise impossible to achieve with traditional processes. It is also digital fabrication and does not require different tools to create the parts, reducing the inherent complexity of the procedure. Finally, it significantly shortens the time from design to prototype to final production.
- Easier and faster design with far fewer constraints
- Functional pieces with many different materials
- Much more room for creativity and innovation
- Thousands of pieces in 3/4 working days without the cost of the mould
What are the practical applications of 3D printing?
It can be used today to quickly make both prototypes and finished products in large quantities. It can also be used to make complex shapes that would be impossible to make with traditional methods.
It is also digital manufacturing and does not require different tools to create the parts, reducing the intrinsic complexity of the procedure. Finally, it greatly shortens the times that go from design to prototype to final production.
1. Industrial production
Depending on manufacturing methods, 3D printing processes and post processing costs in the 3D printing industry are in general going down, and mechanical properties are almost as good as with traditional manufacturing. More and more parts are being made in large quantities with 3D printing.
Run of pieces printed on PA12 nylon with Multi Jet Fusion (MJF) technology
Related article: MJF vs injection molding how to choose?
2. Creating Prototypes
Since the beginning, programs and files in the right format have been used to quickly make prototypes that work, objects that show how something works, and nice models for presentations.
Handle prototypes made in Nylon PA12 with topBLACK® finish
Related Article: Rapid prototyping: purposes, advantages, costs
3. Weight reduction and performance increase
Modern CAD software can make a different 3D model of an object that already exists, but one that is lighter and works better. This can help save energy and reduce pollution, for example.
FDM 3D Printing on Peek CF (Carbon Fiber)
Related Article: All about plastic polymers with Metal Replacement properties
4. Custom prosthetics
In recent years, there has been a clear diffusion of 3D printing also in the medical field, in particular orthopedics.
Today there are many medical sectors in which the various 3D technologies are growing: didactic, educational, templates for spacers in antibiotic material, production of prostheses and external braces and more.
The upper part of this prosthesis was made of white PA12 nylon
4. Creation of moulds
Most of the plastic products that exist today are obtained by injection molding. However, the construction of metal molds is very expensive and requires a very long time. But for many applications it is not strictly necessary that the molds are made of metal and can therefore be made with specific plastics suitable for 3D printing.
Mold made in stereolithography with High-Temp resin
5. Aesthetic prototypes
Some 3D printing technologies such as Polyjet produce very smooth and precise prototypes and are capable of reproducing a final piece with very high fidelity using a range of plastic materials and an almost infinite number of colors. The problem with these interesting technologies is linked to the very high production costs and to the fact that very rarely the pieces can be considered functional but remain pure simulacra.
Aesthetic prototypes of eyewear made with Polyjet technology
WHAT ARE THE DIFFERENT ADDITIVE MANUFACTURING PROCESSES?
1. Melting solids, as FDM
These additive technologies melt a material (such as thread from a coil) into a new shape by layering after being extruded through a nozzle. Specifically, these are the FFF or FDM technologies (basically synonyms).
Schematic representation of FDM FFF printing: a filament a) of plastic material is passed through a heated mobile head b) which melts it and extrudes it, depositing it, layer by layer, in the desired shape c). A mobile platform e) is lowered after each layer has been deposited. For this type of 3D printing technology additional vertical support structures d) are required to support the protruding parts. Credit Paolo Cignoni Wikipedia
The FDM method of 3D printing can make objects that are either horizontal or vertical. A construction platform is passed under an extrusion nozzle as it travels. In order to create a three-dimensional item with this method, thermoplastic material is first heated to the point of melting, and then layer by layer, it is extruded.
As the design comes together, each layer will emerge as a horizontal cross section in the final product. As soon as one layer is done, the printer's nozzle is lowered so that it is ready to add the next layer of plastic. After the item has been made, the materials that were used to hold it up while it was being made can be taken away.
Many companies make use of FDM 3D printing because it enables them to create items with an acceptable level of granular detail. Therefore, engineers put it to use to evaluate how well the components fit together as well as how they seem. It is a method that makes it easier to make small and specialized tools that used to take a long time to make.
Every single one of our 3D printers uses the FFF method of 3D printing. Polylactic acid, more often known as PLA, is the substance that is most frequently used for 3D printing. However in addition to polyetherimide (PEI) and polyether ether ketone, our high-temperature printers are also capable of using a variety of other very strong materials (PEEK and PEEK CF).
Related Article: Fused Deposition Modeling FDM
2. Solidifying liquids, as stereolithography SLA
They are photosensitive polymers, and an LED light or a laser are used to solidify thin resin films one after the other until a solid object is obtained. It offers very smooth surfaces and high resolution.
Schematic representation of stereolithography: a device that emits light a) A laser or DLP or UV LED selectively illuminates the transparent bottom c) of a tank b) filled with a light-curing liquid resin. The solidified resin d) is progressively dragged upwards by a lifting platform). Credit Paolo Cignoni Wikipedia
The process of making things by putting together their component parts is known as stereolithography, which is also more commonly known as SLA 3D printing. This method is one of the most popular and widely used ways to make things.
In order to create the desired three-dimensional form, it first solidifies a liquid resin that is stored in a reservoir, and then uses a powerful laser to do so. In a nutshell, this method transforms photosensitive liquids into solid 3D plastics one layer at a time by using a low-power laser and a process called photopolymerization.
Digital light processing (DLP) is a technology that is comparable to SLA and is sometimes lumped together with it. It is quite similar to the SLA method, with the exception that a projector screen is used instead of a laser.
MSLA, masked stereolithography apparatus, is a very fast type of stereolithography that uses an LCD screen and a strong LED light source to selectively cure photosensitive resin.
As each layer cures, it builds up into a three-dimensional object. The light comes from a group of LEDs and shines on an LCD screen that acts as a mask and lets the user change how it looks.
This approach provides a number of useful advantages. It is possible to produce a large number of products of good quality for a low cost, and it can do it more quickly and precisely than the majority of other 3D printing technologies.
The issue with MSLA 3D printing is that the photosensitive resin used in this sort of 3D printing is more delicate and must be handled with caution.
DLP (Digital Light Processing)
MSLA (Masked Stereolithography Apparatus)
Learn more: MSLA Stereolithography
3. Powders that melt as selective laser sintering SLS or MJF
Or powder bed fusion as well, represents the most "industrial" technology of 3D printing. The base material is a powder mixed with a binder or a simple powder of the final material which melts with the heat of a laser or light. In its variant MJF (multi jet fusion) it produces pieces with excellent lead times, mechanical and dimensional characteristics and is used both for prototypes and for mass production.
SLS technology has been very important in the 3D printing industry until the arrival of HP's MJF technology in 2017.
Schematic representation of the process: a mobile head a) selectively binds (by falling glue or by laser sintering) the surface of a bed of powder e); a mobile platform f) progressively lowers the bed and the solidified object d) rests inside the unbound powder. New powder is continuously added to the bed from a powder tank c) by a leveling mechanism b). Credit Paolo Cignoni Wikipedia
MJF 3D printers can build things much faster and more precisely than other types of additive manufacturing that use powder. When compared to parts made with other 3D printing technologies, commercial-grade parts made with HP 3D printers have better surface finishes and better mechanical properties.
MJF 3D printing is probably the most advanced form of additive manufacturing available now. It can really compete with traditional manufacturing methods.
Related Article: What is Multi Jet Fusion (MJF) 3D printing?
Related Article: The 4 Main MJF Materials and their Properties
WHAT MATERIALS CAN YOU 3D PRINT?
3D printing is a fast and convenient way to make prototypes and parts for a variety of applications. But the result will depend on the material used if you want parts with a certain look or certain mechanical and functional properties.
There are a lot of different materials that can be used for 3D printing. Luckily, many of their properties are similar, so in the end, the choice comes down to a small number of flexible, tried-and-true materials.
There are really many materials, but consider that 95% of the printed volumes are made up of only 5% of the most used.
SO WHAT ARE THE 5 MOST USED MATERIALS?
It is noted for its toughness, tensile strength, impact strength, very little moisture absorption and ability to bend without fracture. PA 12 (which is also known as Nylon 12) is an excellent general-use plastic that has extensive additive uses. PA 12 is also known as Nylon 12. Injection molders have been using PA 12 for a long time because of its superior mechanical qualities.
Nylon PA12 has very good mechanical and chemical properties, similar to those of most plastics used in traditional manufacturing. It is also a good choice for many projects, from prototypes to long production runs, because it can be used in many ways and made in many ways.
The problem with this material, though, was that it was colored after it was printed. On the outside, nylon PA12 is grey, but the melted powders on the inside are black. Because of this, it could only be painted or dyed black, which limits its versatility. Varnish, on the other hand, limits the mechanical uses by making the part thicker by a few microns or by covering up small details.
Many customers have felt for a long time that Nylon PA12 should come in more colors. HP has been working nonstop for the past few months to make a white version of PA12 that has the same mechanical properties that people like but can also be colored if needed.
PA11 is manufactured in such a way that it has a smaller negative impact on the surrounding ecosystem and does not call for an excessive amount of resources that do not replenish themselves.
In addition to this, it possesses a high degree of heat resistance, is unaffected by light or the elements, and is very flexible. PA12 can maintain its strength even when the temperature dips below freezing, despite the fact that it isn't as healthy for the environment as other plastics. In general, it is rigid and does not move.
PEEK is being used for 3D printing by more and more industries. PEEK polymer is one of the best materials in the 3D business.
Polyether ether ketone is another name for PEEK. It is an organic thermoplastic polymer that doesn't have any color and gets some of the best results of any thermoplastic in the world.
PEEK is a very interesting choice for a number of different industries because of of his unique qualities. PEEK is already used as one of the main materials in the medical, oil and gas, aerospace, and auto industries. It's the best choice for low-volume production and custom designs where it's hard to make prototypes with metal and other traditional methods.
The ability of High Temp Resin to maintain its shape and size in temperatures as high as 190 degrees Celsius is combined with the fine detail that can be achieved through MSLA technology. Therefore, it is an effective method for producing functional prototypes as well as finished parts, such as molds or connectors.
The High Temp Resin (for high temperatures) is the most thermally efficient resin that can be made with MSLA. It has a HDT temperature of 190 degrees Celsius at 0.45 megapascals. It is very detailed and has a finish that is even and smooth.