Preparation of Thermoplastic Molding Compounds

1 Sizing carbon fiber with compatibie thermopiastic poiymer size 

To aid dispersion of the carbon fiber in the polymer matrix, it is usual to apply a polymer compatible size, normally a lower molecular weight version of the polymer can be used, preferably in a water base (e.g. a polyurethane). If the fiber has an epoxy size, this must be removed by solvent extraction in a solvent degreasing plant. Under some conditions, it is possible to blend 10% epoxy sized fiber. If the thermoplastic polymer is to be used at high temperatures (e.g. PEEK), then the size must be temperature resistant, such as a polyimide. 

The properties of the most common thermoplastics that are used for reinforcing with carbon fibers are given in Appendix 14. 

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