POROUS MOLDS FOR MOLDED FIBER PART MANUFACTURING AND METHOD FOR ADDITIVE MANUFACTURING OF SAME
This disclosure describes systems and methods for creating porous molds using additive manufacturing processes such as three-dimensional (3D) printing. At a high level, it has been found that creating a generally porous mold, or a mold with porous regions or zones, can improve the performance of the mold and the quality of the parts created therefrom. It has further been determined that porous molds can be created using additive manufacturing techniques through manipulation of mold manufacturing parameters such as, but not limited to, layer thickness, number of perimeter layers, fill pattern, and fill density. Through variation of these manufacturing parameters, the porosity of a mold created by an additive manufacturing device, e.g., a 3D printer, can be tailored for use with molded fiber.
1 . A porous mold, comprising:
a porous core; and
a fiber contact screen disposed over the porous core, wherein the fiber contact screen comprises at least a first contact surface and a second contact surface formed at an angle with each other and each characterized by at least a screen infill density based on the angle so that the first and second contact surfaces have a same surface porosity.
2 . The porous mold of claim 1 , wherein the first and second contact surfaces have same or different screen infill patterns based on the angle.
3 . The porous mold of claim 2 , wherein the screen fill pattern of the first and second contact surfaces of the fiber contact screen is selected from a group consisting of: Line, Concentric, Hilbert, Octagonal Spiral, Rectilinear, Honeycomb, Archimedean Chords, Cubic, 3D Honeycomb, and gyroid.
4 . The porous mold of claim 1 , wherein the screen infill density for the first and second contact surfaces are selected from 20%, 40%, 60%, and 80%.
5 . The porous mold of claim 1 , wherein the porous core comprises a first surface parallel to the first contact surface of the fiber contact screen and a second surface parallel to the second contact surface of the fiber contact screen so that the porous core physically supports the fiber contact screen and prevents collapse or deformation of the fiber contact screen by providing a uniform pressure differential over the first and second contact surfaces of the fiber contact screen during a molding operation.
6 . The porous mold of claim 5 , wherein each of the first and second surfaces of the porous core is characterized by a core infill density based on the angle so that the first and second surfaces provide, respectively, uniform physical support to the first and second contact surfaces of the fiber contact screen during the molding operation.
7 . The porous mold of claim 6 , wherein the first and second surfaces of the porous core have same or different core infill patterns based on the angle.
8 . The porous mold of claim 7 , wherein the core infill pattern of the first and second surfaces of the porous core is selected from a group consisting of: Line, Concentric, Hilbert, Octagonal Spiral, Rectilinear, Honeycomb, Archimedean Chords, Cubic, 3D Honeycomb, and gyroid.
9 . The porous mold of claim 1 , further comprising a frame supporting portions of the porous core, the frame separated from the porous core by a non-porous wall that prevents fluid flow between the frame and the porous core.
10 . The porous mold of claim 1 , wherein the fiber contact screen is made of a set of layers of material bonded together in a screen infill pattern that facilitates fluid flow from the first contact surface and the second contact surface through the fiber contact screen into the porous core.
11 . The porous mold of claim 1 , wherein the porous core is made of a set of layers of material bonded together in a core fill pattern that facilitates fluid flow through the porous core.
12 . The porous mold of claim 1 , wherein the porous core and the fiber contact screen are created in a continuous 3D printing operation as one unitary body.
13 . The porous mold of claim 12 , wherein the porous core and the fiber contact screen are printed from a different material.
14 . The porous mold of claim 1 , wherein the porous core and the fiber contact screen are created separately and assembled into the porous mold.
15 . The porous mold of claim 1 , wherein each of the first and second contact surfaces is further characterized by at least one of infill pattern, layer height, extrusion diameter, or material.
16 . A porous mold, comprising:
a porous core; and
a fiber contact screen disposed over the porous core, wherein the fiber contact screen comprises a first contact surface oriented at a first angle and a second contact surface oriented at a second angle different from the first angle, wherein the first contact surface is formed by a first set of layers, wherein the second contact surface is formed by a second set of layers, wherein the first set of layers and the second set of layers differ in at least one of infill density, infill pattern, layer height, extrusion diameter, or material, and wherein the first and second contact surfaces have substantially identical surface porosities.
17 . The porous mold of claim 16 , wherein the first set of layers and the second set of layers differ in the infill density.
18 . The porous mold of claim 16 , wherein the first set of layers and the second set of layers differ in the infill pattern.
19 . The porous mold of claim 16 , wherein the first and second contact surfaces have identical surface porosities.
20 . The porous mold of claim 16 , wherein a surface porosity of the fiber contact screen is substantially uniform.