Silicone is in everything from medical implants to baking molds, not to mention gaskets, seals, soft robotics, and artificial heart valves. It’s a highly elastic, biocompatible material that can withstand stress and heat, but it’s hard to 3D print.
Now, Spectroplast, a Swiss start-up, just launched a 3D printer it says can make silicone parts and products with quality and precision on par with injection molded silicone.
This development has the potential to drive the manufacturing of a wide range of customized and complex parts and products that were once too expensive, too slow, or just impossible to produce with traditional silicone methods. It also should bring down the high cost of prototyping in silicone, says company CEO and founder Manuel Schaffner.
Usually, to make a silicone prototype or end-use part, you first need to create a model of the part, use that model to make a mold, then inject silicone into the mold to form the final part. Silicone 3D printing promises to simply print the final part, removing days or months of time and all of the costs associated with mold making.
Silicone Additive Manufacturing
Spectroplast aptly calls its 3D printing technology Silicone Additive Manufacturing (SAM) and its printer is called SAM. It boasts a precision (or Z-axis layer height) of 0.1 mm and the complete freedom of design that comes with nearly all 3D printing processes. The company says products manufactured with SAM are 100% silicone and cannot be distinguished from injection-molded parts in appearance, feel, or performance.
Despite the fact that the SAM 3D printer is new, Spectroplast has years of experience in 3D printing silicone parts. It launched in 2018 as a 3D printing service offering custom silicone parts worldwide, but its technology has been under wraps until now.
In the years that Spectroplast has been providing its silicone-as-a-service, it printed nearly a million silicone parts, says Schaffner. Shipping to customers from its Swiss factory, Spectroplast started with small production runs and prototypes, but now delivers tens of thousands of parts to individual customers.
So why is the company now selling its 3D printer?
“We don’t want the 3D printer to become a competition to our core business as a silicone contract manufacturer, so we’re only providing this system to customers that require an even faster turnaround,” says Schaffner. It was these key customers who asked for their own in-house silicone 3D printing solution to accelerate prototyping. “It’s mainly our audiology customers, so hearing aids, hearing protection, and headphones — that’s the customer group that relies on shorter lead times than we can serve from a contract manufacturing point of view, such as same-day turnarounds.”
A 3D Printing Industry First?
Spectroplast says its machine is the world’s first silicone 3D printer. This may be true depending on how you define silicone and which type of 3D printer you’re referring to. A small handful of 3D printing manufacturers offer printing with silicone-based materials and blends, but they’re not 100% silicone. Some on-demand services claim to print with 100% silicone but they don’t sell their technology.
American 3D printing giant Carbon, for example, offers a proprietary material called SIL 30, which it says is a soft, biocompatible, and tear-resistant silicone urethane elastomer. It has additives that make it 3D printable on its range of 3D printers that also use other polymers. Another American company, Desktop Metal, acquired silicone 3D printing technology when it bought German company EnvisionTec last year. Its 3D-Bioplotter specializes in biomaterial and also prints with the company’s own technical-grade and medical-grade silicone blends.
Spectroplast uses 100% medical grade, ISO-certified silicones and renders them light sensitive, Schaffner says. The process is proprietary, but it’s not too far from today’s resin 3D printers that use light to solidify liquid polymer resins. Schaffner says that any generic silicone can be made accessible to additive manufacturing, and the company has worked with customers to transition their silicone production from injection molding to 3D printing without changes to their existing materials.
“Our one-component material system is similar to moisture-cured silicone in that it just needs an external trigger to initiate the polymerization reaction within the material. In our case, that trigger is light.”
The printer technology, software, and materials are proprietary, and the full process consists of slicing, printing, washing, drying, and post-curing. The printer with periphery equipment will retail close to $100,000.
Spectroplast offers its four TrueSil materials only via its on-demand service but its Medura product line of silicones is now also commercially available through the sale of the 3D printers
Production Applications
As with other 3D printing technologies, large volumes usually make more financial sense with injection molding or other traditional manufacturing. Ideal candidates for 3D printing technology are unique and customized parts in low to mid-size volumes. However, Spectroplast says the silicone 3D printers it uses in-house come in a variety of sizes and the company has a new large-scale silicone 3D printer in the works to enable it to expand further into production 3D printing in silicone.
“By the end of the year, beginning of next year, we will be going live with a platform that is 50 times the size of our current system,” says Schaffner. “So this is a really big leverage in terms of throughput.” The large machine will first be available to customers through Spectroplast’s on-demand service.
SAM Tech Specs
- Volume: 75 x 134 x 100 mm
- Printer Dimensions: 430 x 510 x 820 mm
- Layer Height: 100 μm
- Pixel Size: 70 μm
- Speed: 5 – 8 mm/hr
- Light Engine: UV-LED DLP
- Price: ~$100,000 (printer and all periphery equipment)
License: The text of "New 3D Printer for Silicone Targets Healthcare Industry, Prototypes" by All3DP Pro is licensed under a Creative Commons Attribution 4.0 International License.