Silicone can be printed, and the question is almost always whether it should be. Dedicated machines extrude or jet true silicone and cure it in place, producing genuinely elastomeric parts. Most parts described as printed silicone are not silicone at all but a printed elastomer that behaves similarly, and knowing which you are being offered matters as soon as biocompatibility or temperature comes up.
Which machines do real silicone printing
A small number of machines deposit or jet real silicone and cure it layer by layer with heat or ultraviolet light. They produce parts across a useful hardness range with genuine silicone chemistry. They are specialist, the material set is narrow, and access is through a handful of service providers rather than a general bureau, so lead times and prices are not the ones you are used to.
The elastomers usually offered instead
Printed thermoplastic polyurethane, photopolymer rubber like materials and sintered elastomeric powders all produce flexible parts on common machines. They are excellent for shape, feel and fit. They are not silicone: temperature range, chemical resistance, compression set and biocompatibility are all different, and any of those may be the property that mattered.
Where silicone 3D printing loses to casting and molding
For a handful of soft parts, casting into a silicone tool gives real silicone with better surface and better properties at lower cost. For anything approaching volume, liquid silicone rubber injection molding is far cheaper per part and holds much better tolerances. Printing wins where the geometry cannot be tooled, or where one part is needed tomorrow.
Practical limits of 3D printing silicone
Surface finish is layered rather than glassy, so a printed seal face is unlikely to seal like a molded one. Tolerances are looser than molding and vary with hardness. Compression set on printed elastomers is often worse than on molded silicone, which matters on anything that must stay squashed for years. Test the property that matters rather than the appearance.
Questions people ask about 3d print silicone
Can you 3D print silicone, really?
Yes, on dedicated machines that deposit or jet real silicone and cure it in place. It is a specialist service rather than something a general bureau offers.
Is printed TPU the same as silicone?
No. It is a flexible thermoplastic that feels similar and differs in temperature range, chemical resistance, compression set and biocompatibility.
When should I cast or mould instead?
For a handful of soft parts, casting into a silicone tool is usually better and cheaper. For volume, liquid silicone rubber molding wins on both cost and tolerance.
Can 3D printed silicone seal?
Not as reliably as a molded part, because the layered surface is rougher and compression set is usually worse. Test the seal rather than assuming it.