A French company called Epsilon Composites has developed a production method called pultrusion. As you can guess, it's a form of extrusion where the raw materals are pulled, rather than pushed, through the die. This is because Epsilon's raw material is multiple strands of carbon fiber, which is wound together prior to being pulled through a heated die and impregnated with resin.

The method is used to produce profiles from 3mm to 300mm (less than 1/8" to 11.8") in diameter, with a wall thickness of 0.8mm to 20mm (0.03" to just over 3/4"). The part length is essentially unlimited; if your part can be coiled onto a reel, Epsilon says they can produce a continuous part that's 10km (6.2 miles) long!

Here's a look at the process:

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