Fabrication of fibrous preforms in CMC manufacture

A method of fabricating a fibrous ceramic preform, the method comprising:

• forming a plurality of coated ceramic tows by:
• introducing a polymeric composition to each of a plurality of ceramic tows by drawing each of the plurality of ceramic tows through a bath containing the polymeric composition, wherein the polymeric composition comprises a first polymer binder and a first solvent;
• dispersing and stabilizing each of the plurality of ceramic tows by introducing a dispersing liquid to each of the plurality of ceramic tows such that a coating of a first polymer binder forms on individual filaments of respective ones of the plurality of ceramic tows wherein the dispersing liquid is at least partially immiscible in the first solvent of the polymeric composition;
• incorporating the plurality of coated ceramic tows into a ceramic fabric;
• applying a tackifier composition comprising a second polymer binder and a second solvent to the ceramic fabric;
• and
• incorporating the ceramic fabric into the preform,
• wherein the first polymer binder is insoluble in the second solvent.