Abstract:The effects of viscosity of high toughness epoxy resin on prepreg process technique were investigatedꎬ
and the effects of process parameters during film preparation and impregnation on prepreg quality were discussed. The
highly ̄flexible prepreg with low surface density was successfully fabricated through hot ̄melt method.The physical prop ̄
erties of high ̄flexible prepreg with low surface density were evaluatedꎬ which has a thickness of (25±5) μm and has
stable quality and good manufacturability. Testing results showed that the mechanical properties of the composites
made from the ultra ̄thin prepreg are enhanced especially for the interlaminar fracture toughnessꎬ interlaminar shear
strength and flexural properties. Morphology observation indicated excellent interfacial properties of composites pre ̄
pared from high ̄flexible prepreg with low surface density.