A flexible mandrel for molding a composite material containing a thermosetting resin includes: a body including a contact surface configured to come into contact with the composite material during molding and a non-contact surface configured not to come into contact with the composite material during molding; and at least one hole formed from the non-contact surface toward an inside of the body.

A hybrid mandrel for forming a composite part may comprise a core and a sleeve located around the core. The core may include a rigid material. The sleeve may comprise an elastomeric material. The part may be formed by locating the hybrid mandrel in an injection mold, depositing a molten resin around the hybrid mandrel, curing the molten resin; and removing the hybrid mandrel.

A method of fabricating a composite structure includes laying at least one composite ply about a bladder, the bladder comprising a phase change material in a first phase having a first volume, positioning an outer mold about the bladder and the at least one composite ply, and curing the at least one composite ply to form the composite structure. Curing causes the phase change material contained within the bladder to change to a second phase to expand from the first volume to a second volume and apply a pressure to an interior surface of the composite ply and press an outer surface of the composite ply against the outer mold to form an interior cavity. The bladder is not removable from the formed interior cavity.

The present disclosure encompasses three-dimensional articles comprising flexible-composite materials and methods of manufacturing said three-dimensional articles. More particularly, the present system relates to methods for manufacturing seamless three-dimensional-shaped articles usable for such finished products as airbags/inflatable structures, bags, shoes, and similar three-dimensional products. A preferred manufacturing process combines composite molding methods with specific precursor materials to form fiber-reinforced continuous shaped articles that are flexible and collapsible.

A composite forming method includes manufacturing either one of a composite structure body and a dry preform having a hollow region, and pulling a core out of the hollow region. In the manufacturing, a rubber-made core having a tubular structure is disposed at a portion that forms the hollow region of either one of the composite structure body and the dry preform. The core has a thickness varied in a direction perpendicular to a longitudinal direction to be foldable inward at a thin portion. In the pulling, the core is folded inward with air being discharged from an inside of the core after either one of the composite structure body and the dry preform is manufactured.

A tool for forming a part includes a first tool portion including a first tool surface. The tool further includes a second tool portion comprising a second tool surface facing the first tool surface, wherein the first tool surface and the second tool surface define a tool chamber for forming the part. The tool further includes a bladder subassembly disposed in the tool chamber between the first tool surface and the second tool surface. The bladder subassembly includes a plurality of inner bladders disposed within tool chamber, wherein each inner bladder of the plurality of inner bladders includes an inner bladder chamber that is independently inflatable to selectively apply pressure to the part. The bladder subassembly further includes a bladder cover disposed over the plurality of inner bladders within the tool chamber to provide a barrier between the plurality of inner bladders and the part.

A process for forming a flexible composite driveshaft includes providing a mandrel having a rigid region and a compressible region, applying fiber tape to the mandrel using automated fiber placement with in-situ laser curing in the rigid region and without in-situ laser curing the compressible region, and compressing the fiber tape and compressible material in the compressible region to form diaphragms that extend radially outward to a diameter that is at least twice the size of a diameter of the composite driveshaft in the rigid region.

A method of fabricating a composite structure includes laying at least one composite ply about a bladder, the bladder comprising a phase change material in a first phase having a first volume, positioning an outer mold about the bladder and the at least one composite ply, and curing the at least one composite ply to form the composite structure. Curing causes the phase change material contained within the bladder to change to a second phase to expand from the first volume to a second volume and apply a pressure to an interior surface of the composite ply and press an outer surface of the composite ply against the outer mold to form an interior cavity. The bladder is not removable from the formed interior cavity.

A method for manufacturing a tube body made of fiber-reinforced plastic and used in a power transmission shaft is provided and the method includes: a generating step of disposing an uncured fiber-reinforced resin on a cavity surface of a mold and generating a resin body in a cylindrical shape; and a curing step of supplying a fluid inside the resin body and curing the resin of the resin body.

The invention relates to a method for manufacturing a box-shaped monolithic structure with a cavity by curing a fiber-reinforced prepreg material. The method comprises using two or more elongated and internally hollow support tools which have a complementary form to that of the cavities to be manufactured, and a composition based on reinforcement material and polymer suitable to allow the passage from a rigid state to a flexible elastomeric state and vice versa in response to heating/cooling down. In the rigid state, the support tools allow the direct lamination of the prepreg material on their external walls and are configured to set the flexible elastomeric state at a temperature lower than the curing temperature and higher than 50° C. During the curing operation, the curing pressure is applied both outside the structure being formed and inside the support tools, whose walls have become flexible, to push on the prepreg material to be cured.