A disposable mold core for producing a fiber-reinforced component includes a support core having a granulate and a binder. The support core has a hard shell formed of the binder and the granulate, and an inner core which is binder-free and formed of the granulate. A related method of producing a fiber-reinforced component is disclosed.

Prior to curing a composite workpiece assembly, an expandable element can be inserted into a cavity of the workpiece assembly. The expandable element is configured to expand when a predetermined change is produced in an attribute of the element. The attribute can be a temperature of the element. The element is expanded by producing the predetermined change, and the workpiece assembly is cured while the expanded element is in the cavity, so that the expanded element applies positive pressure to inner surfaces of the cavity during curing. The expanded element can be removed from the cavity after curing. The expanded element can comprise a plurality of expandable pellets.

Prior to curing a composite workpiece assembly, an expandable element can be inserted into a cavity of the workpiece assembly. The expandable element is configured to expand when a predetermined change is produced in an attribute of the element. The attribute can be a temperature of the element. The element is expanded by producing the predetermined change, and the workpiece assembly is cured while the expanded element is in the cavity, so that the expanded element applies positive pressure to inner surfaces of the cavity during curing. The expanded element can be removed from the cavity after curing. The expanded element can comprise a plurality of expandable pellets.

The present invention applies to a molding method for a fiber-reinforced plastic structure having an internal cavity. Firstly, grain groups, which mainly consist of a plurality of high-rigidity grains, are accommodated in bags, and a plurality of cores are formed. A reinforcing fiber substrate, is placed between the plurality of adjacent cores so as to be interposed therebetween. For example, a plurality of molding base materials are prepared by surrounding each core with a prepreg, and the plurality of molding base materials are combined and placed inside a molding die, and the molding base materials are compression molded. When compression molding, a part of the outer surface of the cores is locally pressurized, and the internal pressure of the cores is increased, changing the shape thereof, thus eliminating voids that are present between the cores and the prepreg and/or the prepreg and the molding surface of the die.

The present invention applies to a molding method for a fiber-reinforced plastic structure having an internal cavity. Firstly, grain groups, which mainly consist of a plurality of high-rigidity grains, are accommodated in bags, and a plurality of cores are formed. A reinforcing fiber substrate, is placed between the plurality of adjacent cores so as to be interposed therebetween. For example, a plurality of molding base materials are prepared by surrounding each core with a prepreg, and the plurality of molding base materials are combined and placed inside a molding die, and the molding base materials are compression molded. When compression molding, a part of the outer surface of the cores is locally pressurized, and the internal pressure of the cores is increased, changing the shape thereof, thus eliminating voids that are present between the cores and the prepreg and/or the prepreg and the molding surface of the die.

The invention relates to a process for producing complex, mould-foamed rigid foam materials, more particularly of poly(meth)acrylimide (P(M)I) cores, preferably of polymethacrylimide (PMI) cores, which may be employed, for example, in carmaking or aircraft construction. A feature of the process is that through use of a particulate core during foam, it is possible to achieve an additional weight saving relative to foam materials or sandwich materials of the prior art.

The invention relates to a process for producing complex, mould-foamed rigid foam materials, more particularly of poly(meth)acrylimide (P(M)I) cores, preferably of polymethacrylimide (PMI) cores, which may be employed, for example, in carmaking or aircraft construction. A feature of the process is that through use of a particulate core during foam, it is possible to achieve an additional weight saving relative to foam materials or sandwich materials of the prior art.

A method of producing an operating fluid tank includes providing a mold core produced from a mold core material. The mold core has a holding region, by which the mold core is held in a tool mold or in a plastic molding machine. The mold core is surrounded with a plastic melt, and an opening remains in the operating fluid tank. The mold core material is removed from the operating fluid tank by the remaining opening, and a structural element is arranged at the mold core separate from the holding region, and is held by the mold core while being surrounded with the plastic melt. An inner surface of the operating fluid tank is then formed, to which a structural feature arranged on the structural element is transferred. The structural element is removed from the operating fluid tank through the remaining opening after at least partial hardening of the melt.

Lightweight and strong components having any desired shape, form, or geometry may be manufactured using thermally expanding mandrels by the processes described herein. A thermally expanding mandrel may be formed from an expanding material composition including thermally expanding particles, e.g., micronized rubber particles, and water-soluble binder material, e.g., gypsum plaster. Component material may be applied to the mandrel, and the mandrel may be inserted into a molding tool. Upon application of heat to the mandrel, the mandrel may expand, and compress and cure the component material into a component within the molding tool. Following formation of the component, the mandrel may be washed out of the component, e.g., using pressurized water, and the expanding material composition may be recycled and/or reused.

A method of manufacturing a composite vessel assembly (20) includes the steps of filling a first chamber defined by a first liner (28,30,32) with a first granulated material (96) through a first orifice (98) in the first liner. A vacuum is then applied to the first chamber, and the first orifice is plugged. The first liner may then be enveloped with a first layer (84) for structural rigidity followed by relief of the vacuum.