Usually the viscosity of thermoplastic materials is much too high for this process. Do you have any specific material in mind or a specific reason for using thermoplastic material as matrice?

Correct Matthias.

Haneen, did you already think on Caprolactm which resuts after polymerization to Polyamid. Caprolactam has an extrem low viscosity!

Regards Peter

You may also want to try the product called Elium from Arkema.

David

Tanks Matthias, Peter Eyerer and David for their answering my question.Yes, I want to use thermoplastic materials as matrices because it have good fracture resistance and dimension stability compare with thermosetting materials. In addition, I have a reason for using this process because I think this process will help me to replace compression molding which is used to manufacture  fiber reinforced thermoplastic by vacuum infusion technique.

In addition to caprolactam proposed by Peter, you may also consider using cyclics materials that gives you PBT after polymerisation. See http://www.cyclics.com/index.php for details. However, one problem in using thermoplastic monomers (or oligomers) in infusion (beside costs) may be that they require high temperatures and inert atmosphere (usually oxygen and/or moisture free). That gives you tuff requirements for the sealing and bagging materials. Also the resulting polymer is often very crystalline which reduces the ductility.

Thank you Maciej for your answering, so I can understand from your answer that this process is unsuitable for thermoplastic materials or may I try first?

No, it is fully possible to infuse thermoplastic monomer, in particular if you consider that people do manufacture CF/PEEK in autoclaves. However, it's rather more difficult compared to say standard epoxy or vinyl esters. In summary, in order to cope with the temperatures, a good starting point is high temperature bagging film (Kapton, Upilex, or soft Al foil) and vulcanising tacky tape. I also believe that the vacuum in a vacuum infusion process is sufficient to provide the necessary inert atmosphere, but I'm not a chemist so that's needs to be verified by somebody who understand polymerisation chemistry.

What Maciej described sounds rather expensive. If the final costs of your process are not relevant and you have the resources (especially time) to try it, you can go for it.

However, you can also change the fibres/rovings in your composite structure to meet your requirements, for example by using Aramid fibres. If you already have a running process for thermosetting materials, this might reduce costs.