"extruded" carbon tube?
About 15 years ago I came up with a technique for "extruding" carbon rod. I use 6k tow and for a .25" rod I wrap 45 strands of the tow around two nails spaced slightly further apart than the rod length I want to make. I take a wire bent in half,again slightly longer than the part, with the ends also bent over and run it thru one end of the loop made by wrapping the tow. The two loose ends of the tow are tied together. I cut a piece of silicone tube with an ID the same as I want the finished part to be and after wetting out the fiber hanging off the wire I push both free ends of the wire thru the silicone tube and grab them with a pair of vice grips and holding the silicone tube with one hand pull the wetted out strands thru the tube. The tube is then placed in a mold made out of almost anything; a solid rod of immense stength-and in any shape- is produced this way. If the fibers are not twisted during the pull thru, the resulting rod will have low torsoinal strenth; if the fibers are twisted during pull thru the resulting rod is much stronger torsionally.
I'm really interested in seeing if this method or any simple method could be modified to produce a tube instead of a rod; any ideas?