What Is 3D Printing?
3D printing is a manufacturing method used to create three-dimensional artifacts or products that have been designed on a computer. It is also known as desktop fabrication or additive manufacturing.
It is a prototyping process where a real object is created through a 3D design. 3D printers come in all shapes and sizes but they all have one thing in common- they are computer-controlled additive manufacturing machines.
They work in a similar way to paper printers. Paper printers lay down the ink in one layer to create an image whereas 3D printers lay down or cure material in several layers to create a 3D object.
The printers themselves as machines fall under different categories. They are controlled by computers making them Computer Numerical Controlled (or CNC) machines.
They are labeled as additive manufacturing machines because instead of the machine cutting or drilling parts out of raw material into a 3D shape (this is known as subtractive manufacturing), the 3D printers add material bit by bit in the form of layers to create an object or a product.
They are inefficient at scale or in an industrial setting as they take many hours to make the layers of a single object. While other methods of creating products like injection molding produce potentially stronger objects in a matter of minutes.
So Why Use Them?
3D printers are inexpensive, allowing anyone the ability to make a 3D object from a design which is very useful for designers and other creatives or even engineers to use the 3D objects as models for presentations and conceptual illustrations.
Other than testing out product ideas as stated previously, 3D printers have a large number of applications. Manufacturing companies use them to make complex parts for assembly lines, in a cost-effective manner and makers use them for DIY fabrication of anything they design or imagine in their heads.
They are a great way to develop prototypes of products rapidly, allowing them to be modified, tested and reworked time and time again before a product is produced on a full scale.
3D printing is a hands-off manufacturing process and because of the way that objects are created, they can make many parts with intricate geometrics including things like prosthetics or to scale building replicas.
Can You 3D Print Silicone?
3D printing can make objects out of many different materials. Examples of this include ABS plastic, PLA, nylon, glass-filled polyamide, epoxy resins, silver, titanium, steel, wax, photopolymers, and polycarbonate.
Most recently, silicone has been included in that list and it is now possible to create 3D objects out of silicone. Silicone or polysiloxane can be made into all sorts of products including lubricants and hard resins as well rubber-like products.
Silicone has excellent temperature and UV resistance as well as really consistent physical properties. The solid products you see on the market are usually made by mold injection manufacturing processes but now, it is possible to 3D print silicone.
However, it is not easily accessible as of yet to all. There are a few high-end 3D printing processes that are specifically adapted to 3D print silicone but in terms of being readily available to consumers, this is not a reality currently.
Everyone in the 3D printing silicone space are providing either on-demand 3D printing services or the provide the actual printers on a contractual or rented basis.
How Can Silicone Be 3D Printed?
Conventional 3D printers such as filament-based FDM 3D printers or resin-based SLA/DLP 3D printers cannot handle 3D printing with silicone.
This is because of the non-reversible nature of silicone- it does not exhibit normal thermoplastic properties of melting into a liquid at high temperatures and cooling to a solid.
Instead, silicone undergoes a non-reversible reaction where once it is molded and cannot be liquefied.
The thermal stability of solid silicone at extreme temperatures means you cannot put it through a filament-based 3D printer and expect a silicone object to come out because even when it is melted, it doesn’t hold its shape to be extruded.
Silicone is also UV resistant which means that it cannot be cured like resins can be in resin-based printers.
The industrial 3D printers that can print silicone used in chemical and engineering space use Drop-on-demand printers like Aceo (the in-house drop jet solution of 3D printed silicone). A silicone object by planting a voxel of silicone solution (a silicone plus a UV activated binder) one at a time.
After each layer, a UV light source activates the binder and the next layer is planted. Support structures are printed with a water-soluble material to be dissolved post-processing.
Another option industries use is modified resin-based 3D printers where liquid silicone is mixed with a photosensitive resin base where the vat is filled with the silicone resin and after processing a pure silicone part is left behind.
Lastly, Liquid Additive Manufacturing or LAM is similar to FDM 3D printing with modifications to make it suitable for liquid silicone- it is essentially a cure-based FDM process- where liquid silicone rubber is extruded onto a build plate where a halogen lamp heats the extruded layer to enable molecular cross-linking; converting a liquid silicone to a solid.
The Pros And Cons Of 3D Printed Silicone
Because it is not yet available to consumers it is difficult to ascertain the cost of 3D printing of silicone and all of the 3D printing solutions currently available are all offered on a custom quotation basis.
If you want to 3D print silicone, the printer alone is currently quite expensive and so would only be suited to engineering uses at the moment.
However, 3D printed silicone demonstrates similar physical properties to its mold injected counterparts and is extremely thermal stable, extremely high resistance to UV and other weather conditions, it is non-conductive and retains flexibility and its elastic nature when subject to compression.
It is also inert and non-toxic.
In the future, 3D-printed silicones could be used as biomedical implants and artificial organs that are ultra-customized to fit patient needs as well as the development of highly engineered seals that minimize material use to maximize airtightness.
Other consumer goods could be custom 3D printed such as clothes and fashion accessories made to size overnight or even soft, flexible robots that could help the daily lives of the everyday man.
The development of 3D printed silicones on a mass scale represents a revolutionary advancement in the materials science space and while still in its infancy, 3D printed silicone is the way of the future.
Frequently Asked Questions
Can I Buy Silicone Filaments And Resins?
Currently, these are not available on the consumer market as most 3D printers have been developed by private companies that are not machine manufacturers. Also, some of the filaments and resins found online are not the real article so be careful what you purchase and from where if you do.
How Much Do Silicone 3D Printers Cost?
At the moment, silicone 3D printers cost anywhere from $30,000 to $150,000 but are not at the moment for general consumer purchase.
What Can Be Used Instead Of Silicone?
Thermoplastic elastomers like TPU are good alternatives to silicone for 3D printing because of their good shock absorption, tear-resistance, and good impact strength.