Two of the most popular brands of TPE filament on the market are FilaFlex and NinjaFlex. They are unique materials that can be used to print on their own or with a dual extruder to create composite printed parts with a harder material.
Note that due to the elasticity of the material, normal gear extruders cannot feed the filament through the PTFE tube inside the extruder which guides filament through. Due to the increased friction of the material, the filament bends and breaks.
We have developed a flexible material extruder which can be used in our printers to print with flexible materials. Contact us directly in order to try this special extruder as it is still in development.