There have been few more exciting advancements in manufacturing than silicone 3D printing. Manufacturers have only begun using silicone in 3D printing in the last few years as technological advancements have recently made it possible. The future of silicone 3D printing is full of potential.
Traditionally, manufacturers have used silicone as a mold material with which to make other 3D objects. Now, modern science has figured out a way to use silicone to make the objects themselves. Silicone 3D printing now has far-reaching implications in many areas of our lives, including healthcare, transportation, and robotics.
Silicone 3D printing is still a relatively new industry, and there are just a handful of players in the game. Today we will show you how silicone 3D printing works, why silicone 3D printing is so useful, and list the companies that revolutionize the 3D printing industry with their silicone printing technology.
What is Silicone?
Silicone is a polymer that was discovered in 1854. Silicone is made up of silicon, hydrogen, oxygen, and carbon. It exists as a flexible, rubber-like substance. We can now inexpensively mass-produce silicone. It is a versatile product because it is:
- Insulating with thermal stability (as low as -100°C and as high as +300°C)
- Watertight and a great sealant
- Resists UV rays, oxidation, and fire
- Extremely flexible and difficult to tear or damage
- Both electrically conductive or insulating
- Biocompatible (great for bodily implants)
- Safe and non-toxic (food safe)
- Transparent, or comes in a variety of colors
That’s why 3D printing with silicone is such a game-changer! It’s a miracle product with many beneficial applications to improve lives. There are probably many more than we haven’t even thought of yet.
How is silicone used in 3D printing?
Traditional 3D printing materials are called filaments. They are spools of solid plastic or metal. The 3D printer melts the filament during the printing process then the final product is allowed to harden again. This process is impossible with silicone, which is why there hasn’t been a 3D printing material until recently.
Silicone needs to be in its liquid form before printing. Before 3D silicone printers were invented, silicone objects were made by injecting silicone into solid molds. Silicone molds are extremely expensive to make, with the priciest in the $100,000 range!
So to 3D print with silicone, someone had to invent a new type of printer that could use a liquid instead of a filament. In 2016, a company called ACEO designed a printer that could print using liquid silicone rubber (LSR), and other companies have followed suit.
What is the process of 3D printing with silicone?
Silicone 3D printers need to start with the silicone in its liquid form. The liquid is pumped through the machine and is deposited in place, drop by drop, through a tiny nozzle, kind of like an inkjet printer.
Once a single layer has been completed, the silicone is cured with UV light or heat. This curing process binds the molecules together to form a solid layer. The printer then continues to add silicone, layer by layer, until the final product is complete.
Advantages of silicone 3D printing
Silicone itself offers many advantages, but when you combine silicone with 3D printing, those advantages increase exponentially.
Rapid prototyping: Ideas can become a physical reality relatively quickly. Designers can print silicone prototypes faster than ever before, then make adjustments or corrections and print subsequent prototypes without added cost.
Low-volume production: 3D printing with silicone makes producing low volumes of product much more feasible. As we mentioned, injection molding with silicone is astronomically expensive so it was never economical to produce in low numbers until 3D silicone printing came along.
New levels of customization: 3D silicone printers can produce one-time, custom medical products such as implants for an individual patient. They also create custom gaskets for specialized tools and machines without the high start-up costs of injection mold printing.
New geometrical possibilities: 3D silicone printing releases the creative mind, and structures are limited only to the designer’s imagination. Intricate, interconnected channels are created inside silicone objects, which was impossible before. Silicone 3D printers can create an object that is as small as 0.6 mm wide.
Limits of 3D printed silicone
3D printing with silicone is far from perfect. Here are some drawbacks to the process.
Hardware and material availability: The industry is still young, so there are very few companies that offer 3D silicone printing. Household silicone printers aren’t cost-effective just yet. Some companies offer online printing services, where the consumer sends a computer file to get printed and sent back.
Long finishing process: A silicone 3D printer can print only one object at a time, and each layer of the object needs curing with UV light. It takes a long time, so it’s not the best process for big production runs.
Need for UV curing agents: 3D printers can’t print using pure silicone. UV curing agents can weaken the silicone and reduce its lifespan and quality.
Can’t return to its liquid state: Once a silicone printed object is hard, you can’t melt it down again and reuse it. So once it’s done, it’s done. If you make a mistake, there is nothing you can do but try again with more silicone.
Silicone 3D printing: How it works
Different silicone 3D printing companies use other printing methods, but most use a similar three-step process: deposition, vulcanizing or curing, and post-processing.
Designers use software to create virtual plans for the object, and these plans are passed on electronically to the printer. The silicone 3D printer then pumps liquid silicone through a tiny nozzle and deposits the silicone onto a smooth surface one drop at a time, creating layers of 2D objects.
2. Curing or vulcanizing
The silicone will stay in a liquid or gel form until it is cured. Also called vulcanizing or catalyzing, the process forms cross-links in the polymer chain and stiffens and permanently hardens the silicone.
Some printers use UV light or heat during this stage, while others use room-temperature vulcanizing silicone (RTV) that cures by adding another substance.
The final object needs to be cured once more before it is complete and at full strength. Post-processing involves placing the object in an oven to create even more chemical reactions in silicone.
During deposition, gaps, holes, and channels are filled with soluble support material. Post-processing will wash away these materials and leave the holes behind.
Types of silicone 3D printers
There’s more than one way to 3D print with silicone, and companies have come up with their technologies and techniques.
Deposition 3D silicone printers
Deposition printers use liquid silicone rubber (LSR). It is pumped through the machine and deposited in drops through an extrusion head onto a smooth surface. Each layer is cured with UV light. The layers themselves then fuse to create a homogeneous surface.
When the object is ready, the post-process consists of washing the object to remove any soluble support materials from the gaps and holes, then cured again with heat to remove “volatiles” and have the polymer chains get as strong as they can be.
Other deposition-type printers use an extrusion print head to deposit a type of liquid silicone that doesn’t need UV curing. They use room temperature vulcanization (RTV) silicones, some of which only need humidity and a catalyst to cure. Others vulcanize when two components are mixed, which is done with a printer that has dual print heads.
Also called stereolithography, vat photopolymerization is an older technology that was developed in the 1970s. It starts with a vat of liquid silicone. Next, a platform is slightly submerged into the vat. The printer shines targeted UV light into the silicone that is submerged. Only the silicone required to create the object is cured.
The cured silicone turns solid and the uncured silicone remains liquid. This is done layer by layer, as the platform is slowly submerged lower and lower into the vat of liquid silicone until the object is complete. Then the object is washed and cured again in the post process to increase its strength.
Applications of Silicone 3D Printing
Applications of silicone 3D printing are staggering. Here are some of the most common and important ways we can use silicone 3D printing.
Silicone is biocompatible and can be sterilized, so it is perfect for the medical industry. Silicone is already found in things such as
- Feeding tubes
- Respiratory masks
- Hearing aids
Where 3D printing with silicone comes in is for custom items. Medical professionals can create customized implants that perfectly fit a patient’s body. Prosthetic technicians create artificial ears and noses that fit the contours of a patient’s face.
The dental industry is a perfect setting for 3D printing with silicone. Dental technicians can use silicone gum models to recreate a patient’s mouth to create super-accurate dental devices.
Silicone is excellent for insulation and casings for electronic components. It can protect electronic mechanisms from vibrations and significant temperature fluctuations. A big advantage of 3D printing with silicone is creating overlapping channels and tubes, which was not possible with mold-injection techniques.
Soft robotics is the creation of robots that look and feel like living things. Silicone is useful for creating gripping tools that won’t break the objects they grab. Silicone’s properties of thermal stability, electrical insularity, and biocompatibility make it perfect for soft robotics.
3D printing comes in handy for creating prototypes during the development process or for creating one-off parts.
Silicone 3D printed objects are watertight, so they make great seals and gaskets for industrial use. Seals and gaskets are produced in high volumes, so 3D printing is used mainly for prototypes and testing. 3D printing prototypes reduce the time it takes to get a product on the market.
Best Silicone 3D Printing Services
Silicone filaments and resins aren’t available on the market, and the most dedicated silicone 3D printer costs tens of thousands of dollars. For the time being, the easiest method to 3D print in silicone is through a silicone 3D printing service.
This German-based company is credited with developing the first silicone 3D printing process. The company promises a quote within 48 hours and can have your product ready in as little as 10 days. ACEO can create a silicone object up to 200 cubic centimeters in size.
They are a company in Switzerland that specializes in biocompatible medical pieces. It uses a vat photopolymerization printing process. Spectroplast will complete your first order in seven days.
Using a deposition printer, this company in France can create larger objects than other printing services (390 mm x 600 mm).
This is also a medical-grade specialty printer that boasts that its three 3D BioPlotter printers are the “most seasoned bio-printers on the market, backed by more than 150 research papers.”
The company based in the USA creates sports apparel and wearables such as watch bands. It has a patented Digital Light Synthesis, which is a quicker version of vat photopolymerization and uses its own silicone-urethane recipe.
This company near Munich teamed up with the Dow Chemical Company to create its deposition 3D silicone printer. German RepRap specializes in aerospace and automotive parts. It also offers polyurethane printing.
How much do silicone 3D printers cost?
Silicone 3D printers are pricey. They start at around $30,000 each and can go as high as $150,000. Most commercial silicone 3D printers aren’t for sale to the general public. It’s why most people need to order silicone-printed objects through a third party.
Can 3D printers use silicone?
Your 3D printer at home can’t use silicone. Not yet, anyway. That’s because silicone needs to be a liquid and not a filament. Your typical 3D printers these days use filaments made of plastics or metal.
What’s cheaper? Silicone 3D printing or silicone injection molding?
Silicone 3D printing is cheaper if you are producing low numbers of products. Spectroplast estimates that silicone 3D printing is cheaper for production runs of less than 6,000 units. More than that and silicone injection molding becomes the cheaper way to go.
Silicone 3D Printing: Final Thoughts
Silicone 3D printing is one of the most exciting leaps forward in design and manufacturing in decades. Its applications for human health and longevity will no doubt positively affect our lives.
The next few years will see the cost of silicone 3D printers come down, and it will no longer be the domain of a few corporations. This increased access has amazing potential for places like hospitals, which will have the ability to create custom-made medical devices and implants quickly and in-house, without using third parties.
As silicone printing becomes more accessible, the general public will have better access to silicone 3D printers and they could soon be part of your household electronics.