"A Balzano et al. Effective properties of carbon fiber composites: EM modeling versus experimental testing" may be helpful.

try powder mwtallurgy using nano sized particles may be helpful

1. Preparation of thin short-CF suspension in organic liquid by sonification.

2. Adding small amounts of powder to the suspension while treating in a high-speed propeller mixer gradually.

3. Intensive vacuum drying.

The method of Mr Shabalin is really helpful.

Ultrasonic concussion in organic liquid is helpful to deal with entangling.

Ball milling sometimes is useful method for dealing with powder

Consider to add isopropyl alcohol as binder-assisting agent, in order to improve the homogeneity the intended mixture. You can evaporate the alcohol with moderate heat and/or vacuum assistance after the mixture has been sufficiently accomplished.