Fluted core sandwich panels are joined together to form a composite structure. Variations in panel ends are accommodated by a core stiffener insert installed in a joint between ends of the panels.

A method of producing a cellular structure via an additive manufacturing technique includes the steps of: providing a feedstock material to an additive manufacturing printer device; dispensing the feedstock material from the printer device; and controlling the dispensing of the feedstock material to form at least one layer of the cellular structure according to a first predetermined gradient. In some aspects, the cellular structure comprises an array of cells surrounded, respectively, by walls, and arranged to create a non-uniform relative density and/or cell geometry across a width and/or a height of the cellular structure. An article of manufacture produced by such methods includes a cellular structure configured to produce a controlled collapse with selectable dynamic stiffness characteristics by altering the distribution and geometry of cells within the cellular structure, while being able to maintain a substantially similar static stiffness characteristic.

A method of manufacturing a resin-laminated board by preparing a pair of first and second split molds each of which is provided with a cavity; positioning two sheet materials made of a thermoplastic resin between the first and second split molds with the cavities of the first and second split molds opposed to each other; forming a plurality of recesses by recessing a first sheet material toward a second sheet material with use of a plurality of protrusions provided to the first split mold; and welding bottoms of the recesses to the second sheet material by clamping the pair of first and second split molds to obtain a resin-laminated board with a hollow structure. A mold includes a plurality of piece members, disposed at the cavity of the first split mold; and includes the protrusions and male screws provided to base ends of the protrusions.

A method of manufacturing a resin-laminated board by preparing a pair of first and second split molds each of which is provided with a cavity; positioning two sheet materials made of a thermoplastic resin between the first and second split molds with the cavities of the first and second split molds opposed to each other; forming a plurality of recesses by recessing a first sheet material toward a second sheet material with use of a plurality of protrusions provided to the first split mold; and welding bottoms of the recesses to the second sheet material by clamping the pair of first and second split molds to obtain a resin-laminated board with a hollow structure. A mold includes a plurality of piece members, disposed at the cavity of the first split mold; and includes the protrusions and male screws provided to base ends of the protrusions.

The instant disclosure provides a die assembly for producing an annular microcapillary product. The die assembly is operatively connectable to an extruder having a thermoplastic material passing therethrough. The die assembly includes a shell, an inner manifold, an outer manifold, and a die assembly. The inner and outer manifolds are positionable in the shell with matrix flow channels thereabout to receive the thermoplastic material therethrough such that matrix layers of the thermoplastic material are extrudable therefrom. The die insert is disposable between the inner and the outer manifolds, and has a distribution manifold with a tip at an end thereof defining microcapillary channels to pass a microcapillary material therethrough whereby microcapillaries are formed between the matrix layers.

A composite material for producing an extrudate may include: PVC and granules of cercal chaff. The granules of cereal chaff may include spelt, hulls, granules, seed coats and/or stem parts. The cereal may be Pooideae and/or Panicoideae and/or Andropogonoide-ae.

Retention features are provided for joining at least two structural components in a fixtureless assembly system. A first structure including a groove may be configured to contain at least one adhesive, and a second structure may include a tongue configured to contact the at least one adhesive to join the first and second structures. The first structure may also include at least one window that receives electromagnetic (EM) radiation from an EM radiation source into the groove. The at least one adhesive is configured to cure at a first rate upon exposure to one of time or heating, and the at least one adhesive is configured to cure at a second rate faster than the first rate upon exposure to the EM radiation.

Provided is an extrusion molding apparatus capable of producing a multi tube with which an outer shape of a cross section is close to a perfect circle. The multi-lumen tube extrusion molding apparatus includes a resin supplying portion, a die that has an extrusion port at a lower end portion and molds the multi-lumen tube as the resin supplied from the resin supplying portion is extruded vertically downward, and an outer surface molding apparatus that molds an outer surface of the extruded tube. In a state in which the resin is supplied from the resin supplying portion to the die, the outer surface molding apparatus depressurizes a molding space of circular cylindrical shape in a state in which the extruded tube is contained in the molding space to mold an outer surface of the contained multi-lumen tube to a circular cylindrical shape.