Silicone-Based Sealant Extrusion

Silicone-based sealant is a material that is typically used in bathrooms to make them more "water-tight." It's physical properties make it a very useful filament for 3D printing.

Advantages

This sealant is a fairly unique filament in that it does not require melting to extrude. Printers such as the Fab@home Personal Fabricator would have no problem printing the material, as well as whatever else can be fit into the syringes. It's gel-like properties are such that it can be easily extruded yet still maintain a solid shape upon extrusion. It has shown promising application in a number of areas including reactionware developed by the Cronin Group at the University of Glascow. The Cronin group applies the material to develop custom reaction vessels that will spontaneously reseal when punctured. The vessels can also easily be sliced open and reassembled with glue.

Disadvantages

Because the of the nature of extrusions without melting the filament, there is a loss of resolution when printing. Even when printing at maximum resolution, the print is usually not as smooth as would normally be expected with a melting plastic. However, this is mostly an aesthetic problem; it is not an issue with practical applications such as reactionware.