POWDER CURTAIN PREPREG PROCESS

Powder prepregging processes being developed for advanced composite ma terials overcome many of the difficulties associated with melt, soluti on and slurry prepregging. In addition, studies have demonstrated that powder coating is applicable to thermoplastics and thermosets and tha t processing costs are comparable to conventional hot melt prepregging . The powder curtain prepreg process offers advantages in quality cont rol and powder handling over other methods which utilize fluidized bed s or slurries. The dry powder curtain feed method provides for the uni form metering and efficient application of polymer powder materials on to fiber webs for the manufacture of high quality composite towpreg. T he process has been demonstrated for a wide variety of thermosets and thermoplastic resins. Towpreg, prepared. by the powder curtain method, has been made into unidirectional and woven composite test specimens that have exhibited excellent mechanical properties.