The present invention is directed to a 3D printed mold for creating three dimensional pulp products from a fibrous pulp slurry. Transverse filaments are integrated into an infill structure with an open-cell pattern. The transverse filaments form channels through the interior matrix of the mold. The open cell infill pattern and channels allow for the movement of vacuumed materials through the interior matrix of the 3D printed mold when vacuum pressure is applied. The product surface of the mold comprises an array of beads formed from the over-extrusion of melted material at the ends of the transverse filaments. The beaded array narrows the opening of the channels created by the transverse filaments, preventing the fibers from entering the matrix of the mold and clogging the flow of materials. This causes the fibers to aggregate on the product surface of the mold, forming the three dimensional pulp product.

A honeycomb structure having a core made up of a plurality of corrugated sheets which are superposed and adhesively bonded together is described. The corrugated sheets are made from a thermally insulating material. Bear filaments are made up of thermally conductive filaments. The honeycomb structure can be used when the ambient temperature exceeds, for example, 120 C.

A thermoplastic folded honeycomb structure is described which is produced from a material by plastic deformation perpendicular to the plane of the material to thereby form half-hexagonal cell walls and small connection areas. The cell walls in L-direction of the honeycomb core have a wavy shape with an amplitude of about 10% of the cell wall length. A zero slope of the wavy shape at the cell wall connections allows an optimal shear load transfer between the cell walls. By folding in the direction of conveyance the wavy cell walls meet to thereby form the honeycomb structure.

A honeycomb core, formed from a plurality of polygonal cells arranged in an array. Each polygonal cell has lateral cell walls, the lateral cell walls of each polygonal cell forming a polygonal ring, the lateral cell walls being composed of a sheet material, the sheet material being a symmetric three-layer or five-layer thermoplastic co-extruded sheet material having an inner central or core layer and outer layers. The symmetric three-layer or five-layer thermoplastic co-extruded sheet material provides improved mechanical properties compared to a simple sheet material.

Method and apparatus for the production of an optionally large width thermoplastic sandwich panel with composite skins in a 0/90 unidirectional tape layup. The composite skins can be composed of thermoplastic film or sheet material. The method and apparatus allow rapid production of different widths of completed thermoplastic honeycomb sandwich panels. Thermoplastic film or sheet is preferably joined/laminated by thermoplastic welding to a honeycomb core.

The present invention is directed to a 3D printed mold for creating three dimensional pulp products from a fibrous pulp slurry. Transverse filaments are integrated into an infill structure with an open-cell pattern. The transverse filaments form channels through the interior matrix of the mold. The open cell infill pattern and channels allow for the movement of vacuumed materials through the interior matrix of the 3D printed mold when vacuum pressure is applied. The product surface of the mold comprises an array of beads formed from the over-extrusion of melted material at the ends of the transverse filaments. The beaded array narrows the opening of the channels created by the transverse filaments, preventing the fibers from entering the matrix of the mold and clogging the flow of materials. This causes the fibers to aggregate on the product surface of the mold, forming the three dimensional pulp product.

A method for fabrication of a layup for a composite honeycomb core sandwich structure includes laying up a first plurality of unidirectional tows over a tool for layup of the composite honeycomb core sandwich structure using an automated fiber placement process to form a stack of under-core composite plies that are tied down to a rough textured surface bonded to the tool; placing a honeycomb core on the stack of under-core composite plies within the rough textured surface; and laying up a second plurality of unidirectional tows over the honeycomb core using the automated fiber placement process to form a stack of over-core composite plies that tie down the honeycomb core to the rough textured surface. The method may also include placing an under-core film adhesive on the stack of under-core composite plies and placing an over-core film adhesive on the honeycomb core.

A manufacturing system to form a honeycomb core and a method of forming the same includes a sheet of fibrous material is fed into a perforation assembly. The sheet of fibrous material is perforated via the perforation assembly to form holes through the sheet of fibrous material. The sheet of fibrous material is cut to form layers. The layers are stacked on top of each other such that the holes of the layers align with each other and strips of adhesive bond the respective layers together to form a perforated stack. A coating is applied to the sheet of fibrous material at the holes. The perforated stack is expanded to form a honeycomb panel. The honeycomb panel is dipped in a solution, and the coating repels the solution. The solution adheres to the honeycomb panel except at the holes where the coating is applied to form the honeycomb core.