Abstract: This invention relates to an improvement in filament winding large, hollow, tubular structures having significant axial reinforcement in their thick walls by means including (a) using a hollow, light weight mandrel adapted to expand radially at elevated temperatures and windings of alternate layers of filamentary materials positioned substantially axially and substantially circumferentially relative to the longitudinal axis of the mandrel wherein the alternate layers are preferably in a certain thermosettable resin matrix and wound in certain fashion and (b) heating the filament wound mandrel to cure the thermosettable resin wherein heat from inside and out of the mandrel controls the cure and expansion during the heating step. The thick walls preferably incorporate graphite fibers for significant strength in the reinforcement provided by the filamentary materials.

Abstract: This invention relates to an improvement in filament winding large, hollow, tubular structures having significant axial reinforcement in their thick walls by means including (a) using a hollow, light weight mandrel adapted to expand radially at elevated temperatures and windings of alternate layers of filamentary materials positioned substantially axially and substantially circumferentially relative to the longitudinal axis of the mandrel wherein the alternate layers are preferably in a certain thermosettable resin matrix and wound in certain fashion and (b) heating the filament wound mandrel to cure the thermosettable resin wherein heat from inside and out of the mandrel controls the cure and expansion during the heating step. The thick walls preferably incorporate graphite fibers for significant strength in the reinforcement provided by the filamentary materials.

Abstract: This invention relates to an improvement in filament winding large, hollow, tubular structures having significant axial reinforcement in their thick walls by means including (a) using a hollow, light weight mandrel adapted to expand radially at elevated temperatures and windings of alternate layers of filamentary materials positioned substantially axially and substantially circumferentially relative to the longitudinal axis of the mandrel wherein the alternate layers are preferably in a certain thermosettable resin matrix and wound in certain fashion and (b) heating the filament wound mandrel to cure the thermosettable resin wherein heat from inside and out of the mandrel controls the cure and expansion during the heating step. The thick walls preferably incorporate graphite fibers for significant strength in the reinforcement provided by the filamentary materials.