WO2021195527A1

WO2021195527A1 - Perforated structures and thermoforming

Info

Publication number: WO2021195527A1
Application number: PCT/US2021/024409
Authority: WO
Inventors: Dries VANDECRUYS
Original assignee: Materialise N.V.; Materialise Usa, Llc
Priority date: 2020-03-26
Filing date: 2021-03-26
Publication date: 2021-09-30
Also published as: EP4127317A1

Abstract

A system and method for manufacturing and use of a perforated structure for the production of molding products is disclosed. In some examples, the perforated structure includes a first side and a second side opposite the first side. The perforated structure may also include a body separating the first side from the second side, and a plurality of channels formed in the body, wherein one or more of the plurality of channels extending from the first side to the second side. In some examples, the first side defines a contoured surface, and the second side defines a base conformal to a heat source surface.

Description

PERFORATED STRUCTURES AND THERMOFORMING

Cross-Reference to Related Application(s)

[0001] This application claims benefit of and priority to U.S. Provisional Patent Application Serial No. 63/000,153, filed March 26, 2020, herein incorporated by reference in its entirety as if fully set forth below and for all applicable purposes.

BACKGROUND

Field of the Invention

[0001] This application relates to methods and apparatus for producing perforated structures, such as for improved production of molded packaging products.

Description of the Related Technology

[0002] Packaging products molded from paper pulp or fiber pulp are widely used for packaging and transporting products, including food, glass, electronics, etc. One advantage of using pulp-based products is the low cost and high availability of raw pulp materials. Examples of raw pulps materials include newsprint, cardboard, and plant products, many of which are recycled. A further advantage of a pulp-based product is its versatility. Molded packaging products can be designed, and shaped via a molding structure, to accommodate virtually any physical characteristic of a product that is being packaged.

[0003] However, current molding techniques require significant time to produce a completed packaging product. For example, current molding techniques require several steps performed in series. For instance, a first step may include applying a pulp material to a molding structure, followed by a second step of compressing the material against the structure to form it, then followed by removing the compressed material and heating it. Because each of these steps is performed in series, each step requires its own window of time to complete which extends the time required to produce the completed packaging product.

[0004] Moreover, manufacture of the molding structure typically requires additional material structure in order to support various aspects of the molding structure. For example, when manufacturing a molding structure that has one or more nuanced contours or aspects, the molding structure may require additional structures and materials to be added, often by hand, in order to prevent the molding structure from caving or distorting from its own weight and/or the heat of the manufacturing process. [0005] In view of these and other problems, systems and methods that improve production of molded packaging products and the manufacture of molding structures are described herein.

SUMMARY

[0006] In one embodiment, a perforated structure is disclosed. The perforated structure includes a first side and a second side opposite the first side. The perforated structure also includes a body separating the first side from the second side. The perforated structure also includes a plurality of channels formed in the body, one or more of the plurality of channels extending from the first side to the second side, wherein the first side defines a contoured surface, and the second side defines a base conformal to a heat source surface.

[0007] Certain embodiments provide a method for producing a molded product. In some examples, the method includes distributing a material mixture over a first side of a perforated structure comprising a second side opposite the first side, the perforated structure further comprising a body separating the first side from the second side, wherein the first side defines a contoured surface, and wherein the second side defines a base conformal to a heat source surface. The method may also include compressing the material mixture between the first side and a press surface conformal to the first side to displace content from the material mixture via a plurality of channels formed in the body of the perforated structure, wherein one or more of the plurality of channels extend from the first side to the second side. The method also includes separating the compressed material mixture from the first side of the perforated structure, the compressed material mixture forming the molded product.

[0008] Certain embodiments provide a method for generating a perforated structure. In some examples, the method includes receiving a design of the perforated structure, the design indicating a shape, size, and position of the perforated structure relative to a build area corresponding to an additive manufacturing device. In some examples, the design of the perforated structure defines a first side, a second side opposite the first side, a body separating the first side from the second side, and a plurality of channels formed in the body, one or more of the plurality of channels extending from the first side to the second side, wherein the first side defines a contoured surface, and wherein the second side defines a base conformal to a heat source surface. The method may also include causing manufacturing of the perforated structure using additive manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is an example of a system for designing and manufacturing three- dimensional (3D) objects.

[0010] FIG. 2 illustrates a functional block diagram of one example of the computer shown in FIG. 1.

[0011] FIG. 3 illustrates a high level process for manufacturing a 3D object.

[0012] FIGs. 4A and 4B illustrate example additive manufacturing apparatus with a recoating mechanism.

[0013] FIGs. 5A through 5E illustrate different views of an example perforated structure or pressing structure manufactured using an additive manufacturing process that can be used in both of the first and second exemplary molding processes described above.

[0014] FIGs. 6A and 6B illustrate different views of an example perforated structure or pressing structure manufactured using an additive manufacturing process that can be used in both of the first and second exemplary molding processes described above.

[0015] FIGs. 7A and 7B illustrate different views of an example perforated structure or pressing structure manufactured using an additive manufacturing process that can be used in both of the first and second exemplary molding processes described above.

[0016] FIG. 8 is a flowchart of an example process producing a molded product using a perforated structure and a pressing structure.

DETAILED DESCRIPTION

[0017] Systems and methods disclosed herein include techniques for producing perforated structures, and using the perforated structures for improved production of molded packaging products.

[0018] In certain aspects, a perforated structure may be designed on a computing system using any suitable computer-aided design (CAD) software. As discussed later, in some examples, the perforated structure may be designed as a single monolithic structure. Such a design offers a benefit wherein aspects of the perforated structure are self-supporting. That is, during manufacturing of the perforated structure, additional material support is no longer necessary.

[0019] Aspects of the disclosure may be practiced within a system for designing, simulating, and/or manufacturing 3D objects. Turning to FIG. 1, an example of a computer environment suitable for the implementation of 3D object design, build simulation, and manufacturing is shown. The environment includes a system 100. The system 100 includes one or more computers 102a- 102d, which can be, for example, any workstation, server, or other computing device capable of processing information. In some embodiments, each of the computers 102a- 102d can be connected, by any suitable communications technology (e.g., an internet protocol), to a network 105 (e.g., the Internet). Accordingly, the computers 102a-102d may transmit and receive information (e.g., software, digital representations of three dimensional (3D) objects, commands or instructions to operate an additive manufacturing device, etc.) between each other via the network 105.

[0020] The system 100 further includes one or more additive manufacturing devices (e.g., 3D printers) 106a-106b. As shown the additive manufacturing device 106a is directly connected to a computer 102d (and through computer 102d connected to computers 102a- 102c via the network 105) and additive manufacturing device 106b is connected to the computers 102a- 102d via the network 105. Accordingly, one of skill in the art will understand that an additive manufacturing device 106 may be directly connected to a computer 102, connected to a computer 102 via a network 105, and/or connected to a computer 102 via another computer 102 and the network 105.

[0021] It should be noted that though the system 100 is described with respect to a network and one or more computers, the techniques described herein also apply to a single computer 102, which may be directly connected to an additive manufacturing device 106.

[0022] FIG. 2 illustrates a functional block diagram of one example of a computer of FIG. 1. The computer 102a includes a processor 210 in data communication with a memory 220, an input device 230, and an output device 240. In some embodiments, the processor is further in data communication with an optional network interface card 260. Although described separately, it is to be appreciated that functional blocks described with respect to the computer 102a need not be separate structural elements. For example, the processor 210 and memory 220 may be embodied in a single chip.

[0023] The processor 210 can be a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any suitable combination thereof designed to perform the functions described herein. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0024] The processor 210 can be coupled, via one or more buses, to read information from or write information to memory 220. The processor may additionally, or in the alternative, contain memory, such as processor registers. The memory 220 can include processor cache, including a multi-level hierarchical cache in which different levels have different capacities and access speeds. The memory 220 can also include random access memory (RAM), other volatile storage devices, or non-volatile storage devices. The storage can include hard drives, flash memory, etc.

[0025] The processor 210 also may be coupled to an input device 230 and an output device 240 for, respectively, receiving input from and providing output to a user of the computer 102a. Suitable input devices include, but are not limited to, a keyboard, buttons, keys, switches, a pointing device, a mouse, a joystick, a remote control, an infrared detector, a bar code reader, a scanner, a video camera (possibly coupled with video processing software to, e.g., detect hand gestures or facial gestures), a motion detector, or a microphone (possibly coupled to audio processing software to, e.g., detect voice commands). Suitable output devices include, but are not limited to, visual output devices, including displays and printers, audio output devices, including speakers, headphones, earphones, and alarms, additive manufacturing devices, and haptic output devices.

[0026] The processor 210 further may be coupled to a network interface card 260. The network interface card 260 prepares data generated by the processor 210 for transmission via a network according to one or more data transmission protocols. The network interface card 260 also decodes data received via a network according to one or more data transmission protocols. The network interface card 260 can include a transmitter, receiver, or both. In other embodiments, the transmitter and receiver can be two separate components. The network interface card 260, can be embodied as a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any suitable combination thereof designed to perform the functions described herein.

[0027] FIG. 3 illustrates a process 300 for manufacturing a 3D object or device. As shown, at a step 305, a digital representation of the object is designed using a computer, such as the computer 102a. For example, two dimensional (2D) or 3D data may be input to the computer 102a for aiding in designing the digital representation of the 3D object. Continuing at a step 310, information corresponding to the 3D object is sent from the computer 102a to an additive manufacturing device, such as additive manufacturing device 106, and the device 106 commences a manufacturing process for generating the 3D object in accordance with the received information. At a step 315, the additive manufacturing device 106 continues manufacturing the 3D object using suitable materials, such as a polymer or metal powder. Further, at a step 320, the 3D object is generated.

[0028] FIG. 4A illustrates an exemplary additive manufacturing apparatus 400 for generating a 3D object. In this example, the additive manufacturing apparatus 400 is a laser sintering device. The laser sintering device 400 may be used to generate one or more 3D objects layer by layer. The laser sintering device 400, for example, may utilize a powder (e.g., metal, polymer, etc.), such as the powder 414, to build an object a layer at a time as part of a build process.

[0029] Successive powder layers are spread on top of each other using, for example, a recoating mechanism 415A (e.g., a re-coater blade). The recoating mechanism 415A deposits powder for a layer as it moves across the build area, for example in the direction shown, or in the opposite direction if the recoating mechanism 415A is starting from the other side of the build area, such as for another layer of the build. After deposition, a computer-controlled carbon dioxide (C02) laser beam scans the surface and selectively binds together the powder particles of the corresponding cross section of the product. In some embodiments, the laser scanning device 412 is an X axis and Y axis moveable infrared laser source. As such, the laser source can be moved along an X axis and along a Y axis in order to direct its beam to a specific location of the top most layer of powder. Alternatively, in some embodiments, the laser scanning device 412 may comprise a laser scanner which receives a laser beam from a stationary laser source, and deflects it over moveable mirrors to direct the beam to a specified location in the working area of the device. During laser exposure, the powder temperature rises above the material (e.g., glass, polymer, metal) transition point after which adjacent particles flow together to create the 3D object. The device 400 may also optionally include a radiation heater (e.g., an infrared lamp) and/or atmosphere control device 416. The radiation heater may be used to preheat the powder between the recoating of a new powder layer and the scanning of that layer. In some embodiments, the radiation heater may be omitted. The atmosphere control device may be used throughout the process to avoid undesired scenarios such as, for example, powder oxidation.

[0030] In some other embodiments, such as shown with respect to FIG. 4B, a recoating mechanism 415B (e.g., a leveling drum/roller) may be used instead of the recoating mechanism 415A. Accordingly, the powder may be distributed using one or more moveable pistons 418(a) and 418(b) which push powder from a powder container 428(a) and 428(b) into a reservoir 426 which holds the formed object 424. The depth of the reservoir, in turn, is also controlled by a moveable piston 420, which increases the depth of the reservoir 426 via downward movement as additional powder is moved from the powder containers 428(a) and 428(b) in to the reservoir 426. The recoating mechanism 415B, pushes or rolls the powder from the powder container 428(a) and 428(b) into the reservoir 426. Similar to the embodiment shown in FIG. 4A, the embodiment in FIG. 4B may use the radiation heater 416 alone for preheating the powder between recoating and scanning of a layer.

EXAMPLE TECHNIQUES FOR GENERATING AND USING A PERFORATED STRUCTURE FOR PRODUCING MOLDED PRODUCTS

[0031] In certain aspects, a perforated structure (e.g., a molding structure) may be designed according to a shape and size of a specific item. For example, the perforated structure may be shaped and sized such that it can be utilized in a molding process to mold and produce a packaging product that can accommodate the specific item. In certain aspects, the perforated structure may also be optimized for use in different molding processes.

[0032] A first exemplary molding process starts with material in a liquid (e.g., water) or gaseous (e.g., oxygen, carbon dioxide, etc.) mixture like a slurry, which can be distributed or applied over a first side of the perforated structure. The material may include any natural (e.g., wood, straw, etc.) and/or synthetic (e.g., paper, recycled material, etc.) mixture, such as of paper or other fibrous pulp.

[0033] In a first step of the molding process, the material mixture is applied or distributed onto a first surface or first side (e.g., an A-side) of the perforated structure. The material mixture is then subject to compression between the first side of the perforated structure and a pressing structure (e.g., a press mold) substantially conformal to the first side. The compression of the material mixture between the first side and the pressing structure forces displacement of liquid and/or gas from the material mixture and into a plurality of perforations or openings in the first side of the perforated structure. The openings in the first side of the perforated structure may open into one or more channels that extend through a body of the perforated structure and exit out of a second side (e.g., a B-side) of the perforated structure. That is, the openings on the first side may allow the displaced gas/liquid to pass through the perforated structure and out of the second side. In some examples, the second side is opposite the first side, with the body of the perforated structure separating the first side from the second side.

[0034] The compression may displace a significant portion of liquid from the material mixture (e.g., approximately 60% of the water in the material mixture may be displaced via compression). When the desired amount of liquid and/or gas has been pressed out of the material mixture, the remaining material mixture may conform or mold to the shape of the first side of the perforated structure and may be considered to be a molded product. In a second step, pressing structure is separated from the first side of the perforated structure, and the molded product is separated from the perforated structure and dried, for example, in an oven. [0035] As discussed, perforated structures designed for this first exemplary molding process may comprise a first side, a second side opposite the first side, a body separating the first side from the second side, a plurality of channels formed in the body wherein one or more of the plurality of channels extend from the first side to the second side. In certain aspects, the first side is characterized by or “defines” a contoured surface, and the second side defines a base conformal to a heat source surface (e.g., a heating structure). As illustrated and described below, in some examples, the base provides a flat surface to facilitate uniform contact between the base and the heating structure. However, because not every heating structure is flat, the base may also be characterized by one or more contours or shape asymmetries. For example, the base being conformal to the heat source surface may refer to the base having a shape that follows the same contour as the heat source surface. Each perforation in the first side of the perforated device may include an opening into one or more of the plurality of channels in the body of the perforated device. In some examples, a plurality of perforations may be connected via one or more of the plurality of channels.

[0036] In a second exemplary molding process, pressing (e.g., forming) and drying the material mixture may be combined into a single step. In this example, the drying may be performed using thermoforming or hot mold pressing techniques. The second exemplary molding process may be suited for forming pulp-based products with fine contours and details, sharp lines, and/or smooth surfaces. [0037] Similar to the first exemplary molding process, a material mixture may be distributed or applied over a first side of a perforated structure. The material mixture is then subject to compression between the first side of the perforated structure and a pressing structure substantially conformal to the first side, and the heating structure (e.g., a heating shape or heating block) is applied to the second side of the perforated structure. The compression of the material mixture between the first side and the pressing structure forces displacement of liquid and/or gas from the material mixture, through the plurality of perforations in the first side of the perforated structure, and out of the second side of the perforated structure. Thus, the perforated structure is sandwiched between the press mold and the heating structure, so that the press mold contacts the material mixture on the first side of the perforated structure, while the heating block contacts the second side of the perforated structure. It should be noted that while the heating structure produces the heat to bake the material mixture, in some examples, the press mold may also (or exclusively) provide the heat to bake the structure. In some examples, one or more of the press mold and the heating structure include one or more perforations to facilitate rapid venting of liquid and/or gas from the material mixture during pressing and heating.

[0038] In some examples, the pressing structure may be another example of the perforated structure described herein. For example, the pressing structure may be designed to have one or more of the structural characteristics of the perforated structures described in more detail below, and may be manufactured using additive manufacturing techniques. That is, the pressing structure may include one or more perforations and channels throughout the body of the pressing structure, including the support structures (e.g., support structures 580 of FIG. 5E below). As described below, the support structures provide a robust structural support for maintaining the stiffness of the perforated structure. This benefit also enhances the functionality of the pressing structure by providing it with reinforcement across the entire structure. Moreover, similar to the perforated structure, the pressing structure may assist in the ventilation of liquid and/or gas from the material mixture when the molded product is formed. [0039] The heating block enhances and facilitates simultaneous pressing and drying of the material mixture to form the molded product. That is, the heating block transfers heat from the second side of the perforated structure to the first side of the perforated structure, thereby heating the material mixture during pressing. In some examples, the heating block heats the water that has passed through the body to the second side of the perforated structure, thereby forming steam that may be vented out of the perforated structure. The molded material mixture can be dried by the combination of pressing the material mixture to conform to the shape of the first side, heating the water and/or air that is displaced from the material mixture, and venting the displaced water and/or air.

[0040] FIGs. 5A through 5E illustrate different views of an example perforated structure 500 manufactured using an additive manufacturing process that can be used in both of the first and second exemplary molding processes described above. Initially, a design of the perforated structure 500 may be represented by a CAD file, wherein the perforated structure in the design is arranged in a virtual build area corresponding to the build area of an additive manufacturing device (e.g., additive manufacturing device 106 of FIG. 1).

[0041] FIG. 5A illustrates a side view of an example perforated structure 500 for producing molded packaging products. As discussed, the perforated structure 500 includes a first side 510 and a second side 512 opposite the first side 510, wherein the first side 510 is separated from the second side 512 by a body 518. In this example, the perforated structure 500 is divided into four zones: a first zone 502, a second zone 504, a third zone 506, and a fourth zone 508. In this view, while a plurality of perforations are visible only on the second zone 504, it should be noted that in some examples, the perforated structure 500 may be designed with one or more perforations on one or more of the four zones or any other location on the first side 510. Each of the plurality of perforations, including a first perforation 514 provide an opening into the body 518 of the perforated structure 500. As discussed, a material mixture may be distributed onto the first side 510 of the perforated structure 500. Then, a pressing structure 516 that is substantially conformal to the first side 510 may apply compress and mold the material mixture according to the shape of the first side 510. A surface 509 is provided on the second side 512 of the perforated structure 500 for contact with a heating plane, as discussed in more detail below.

[0042] FIG. 5B illustrates a top-side perspective view of the example perforated structure 500. In this view, the outer surfaces of the perforated structure 500 are transparent, showing a plurality of channels 520 that extend through the body 518 of the perforated structure 500. As discussed, one or more of the plurality of channels 520 may connect to an opening or perforation (e.g., a first perforation 514) of the first side 510. Note that the plurality of channels 520 may widen from a relatively narrow (e.g., relatively low regional perimeter or diameter of the channel) perforation in the first side 510 to a relatively wider (e.g., relatively higher regional perimeter or diameter of the channel) channel exit 522 in the second side 512. Such a design of the perforated structure 500 provides advantages in both of the molding process and in the completed molded product. For example, the relatively wider channel exit 522 reduces back pressure caused by heated liquid/gas that is displaced from the material mixture when the pressing structure 516 compresses the material mixture on the first side 510. Moreover, the relatively narrower channel openings on the first side 510 prevent pitting in the material mixture during the molding process, thereby resulting in a stronger completed product.

[0043] Still referring to FIG. 5B, the first zone 502, the second zone 504, the third zone 506, and the fourth zone 508 are visible. As shown, the third zone 506 is a zone without perforations. It should be noted that any zone or region of the perforated structure 500 may include any number and density of perforations arranged in any symmetric, asymmetric, or patterned manner. For example, a relatively large number of holes in a region will increase the rate at which that region dries (e.g., via heat and/or liquid/gas displacement). The porosity of a region in the completed molded product may also be considered by increasing the number of perforations and/or the size of the perforations in the corresponding region of the first side 510 of the perforated structure 500. Accordingly, desired characteristics of the completed molded product may drive aspects of the design of the perforated structure 500.

[0044] FIG. 5C illustrates a top perspective view of the first side 510 of the perforated structure 500. In this view, the first side 510 of the perforated structure 500 is transparent, showing a plurality of channels 520 that extend from the perforations 524 of the first side 510 (e.g., white circles) to the second side 512 through the body 518 of the perforated structure 500. As illustrated, each of the white circles has wider semi-circle around it. In this example, the wider semi-circle is the exit 522 of the channel. As discussed, one or more of the plurality of channels 520 may begin relatively narrow at a perforation on the first side 510, and may become wider as they extend through the body 518. In some examples, the one or more of the plurality of channels 520 may resemble a bottle shape, with the narrow bottle neck region closer to the first side 510 and the wider bottle bottom region closer to the second side 512. It should be noted that the plurality of channels may be any suitable shape (e.g., circular, semi-circular, angular, polygonal, etc.). FIG. 5D illustrates a bottom perspective view of the second side 512 of the perforated structure.

[0045] FIG. 5E illustrates a sectional side view of the perforated structure 500. This view further illustrates the perforations and channels across the designated zones of the first side 510. Because the first side 510 is characterized by several contours and varying levels of elevation, perforations in different regions or locations of the first side 510 may open into a straight channel, a bent channel, or multiple channels. As shown, the first zone 502 includes a plurality of perforations that extend from the first side 510 to the second side 512 through the body 518. For example, a first perforation 531 opens into a first channel 532 that extends linearly through the body 518 and ends at a relatively wider opening 522 in the second side 512. As shown, each of the channels that extend from the first zone 502 are spaced a distance from other channels with body material 533 between them.

[0046] The second zone 504 also includes a plurality of perforations. For example, the second zone 504 includes a second perforation 541 that opens into a second channel 542 that extends through the body 518 at an angle and ends at a relatively wider opening 522 in the second side 512. As shown, second perforation 541 is not linear, and includes a bend or kink, which allows water to flow to the non-parallel second side 512. Such non-linear perforations are not used in conventional mold construction techniques. In this example, the second channel 542 intersects 543 with another channel that corresponds to a perforation in the first zone 502. As discussed, the third zone 506 does not include any perforations.

[0047] The fourth zone 508 also include a plurality of perforations. Similar to the first zone 502, the perforations of the fourth zone 508 open to straight, linear channels. Note that the channels in the fourth zone 508 are shorter than channels in the first zone 502 and second zone 504. As shown in this example, any angular characteristic of a channel is made to align the channel so that it is substantially perpendicular to the flat base of the second side 512 of the perforated structure 500, or so that the channel direction tends to gradually become substantially parallel to other channels. As discussed, the base may in some embodiments not be flat but rather conformal to a surface of a heating structure. As such, perforations in a structural contour of the first side 510 may require a corresponding one or more channels with an angular bend to commonly align the channel direction with other channels. The degree to which the angular bend is made may be commensurate with an angle of the structural contour of the first side 510 relative to the flat base of the second side 512. For example, if the first side 510 is parallel with the flat base of the second side 512, then any channel between the two sides can be substantially linear. However, as illustrated, the second zone 504 has a contour that is nearly at a right angle relative to the flat base. Accordingly, a channel from the second zone 504 may have a relatively more dramatic angular direction, and any channel between the first side 510 and the second side 512 may be straight, bent, kinked, curved, branched, or any combination of these, for example, the channel may be step (e.g., substantially a 90° angle), stepped build up, sawtooth (e.g., angle less than 90°), and/or sawtooth build up. [0048] As illustrated, the second side 512 of the perforated structure 500 is defined by a plurality of support structures 580 extending at least partially between the second side and the first side. The support structures 580 may be part of the body 518 and extend a suitable distance to form the flat base. As such, at least two of the support structures 580 (e.g., two columns) may have a different length relative to each other but extend to a same plane of the second side 512 to result in a flat base. As discussed, the flat base provides a surface to facilitate uniform contact between the base and the heating structure. However, although not illustrated, the base may also be characterized by one or more contours or shape asymmetries. That is, one or more of the support structures 580 may not extend to the same plane of the second side 512, but rather, extend to another length in order to accommodate a heating structure with contours while still providing uniform contact across the base of the perforated structure 500 and the heating structure. The support structures 580 may also be referred to as a tooth, pillar, column (e.g., a plurality of columns), or cone.

[0049] As such, the support structures 580 may be located between channel openings in the second side 512 and may have a thickness defined by the density of perforations and/or channels that run through the body 518. Each of the support structures 580 may be characterized by a first end 581 and a second end 582, wherein the first end 581 may be narrower than the second end 582. Such a shape may provide for the previously discussed bottle shaped opening of one or more channels which provides an advantageous path for venting any heated liquid (e.g., steam) displaced from the material mixture out of the second side 512. That is, negative space (e.g., the first perforation 531, the first channel 532, the second perforation 541, the second channel 542, the channel exit 522, etc.) of the perforated structure 500 may be shaped to improve venting of heat, while the positive space (e.g., the support structures 580, the first end 581 and second end 582, body material 533, and body 518) of the perforated structure 500 provides support that maintains the integrity of the negative space during the printing process and also functions for transferring heat from the second side 512 to the first side 510. Thus, negative spaces and positive spaces of the perforated structure may be designed to balance a requirement for heat transfer (via positive spaces) to the first side 510 of the perforated structure 500 with a requirement for venting (via negative spaces) hot liquid and/or gasses out of the second side 512.

[0050] In certain aspects, the support structures 580 enhance heat transfer through the perforated structure 500 by facilitating an even distribution of heat throughout the second side 512 of the perforated structure 500. Because the support structures 580 provide a surface conformal to the heating structure for (e.g., optimal) heat transfer (e.g., each region of the second side 512 of the perforated structure 500 has substantially the same amount of surface area in contact with the heating structure as another region of the second side 512), and heat variations across different regions of the first side 510 are reduced.

[0051] Thus, the perforated structure 500 can be designed such that radiated heat received at the second side 512 can be uniformly transferred to the first side 510. It should be noted however, the perforated structure 500 may also be designed such that certain regions of the first side 510 become hotter than other regions. For example, temperature distribution may be intentionally varied across different regions. Accordingly, because the support structures 580 provide a surface conformal to the heating structure, the characteristics of heat transfer through the perforated structure 500 are relatively easy to predict. This provides an advantage over conventional molds that have “air gaps” due to the mold not being conformal to a heating block, such as flat or contoured, and therefore unable to contact a heating block directly in certain places. The ability for heat to transfer effectively through such air gaps introduces a level of uncertainty into the design of a mold. Thus, with conventional moldings, areas of the mold might bum the molding material while other areas may receive very little heat, if any.

[0052] For example, in traditional manufacturing, molding structures are made by milling the overall shape of the mold out of a block of metal. In some cases, after the milling process, holes are drilled conformal to the surface of the mold. Typically, the holes are drilled using relatively thin drills. This process of milling and drilling has challenges typically related to the slow pace of the process, the relatively high costs associated with the process, and other costs associated with time and material (e.g., if a drill bit breaks inside the mold during the drilling process). Traditional manufacturing may also include the drilling of “blind holes” which relate to holes that are drilled into a first surface of the mold but do not extend through a second surface of the mold. For example, a hole may be drilled partway into the mold from the first side, then another hole may be drilled into the mold from the second side with the intention of meeting or intersecting the two holes. However, if the two drilling operations are not properly aligned, then the two holes may not meet (which simply results in a cavity in the mold), or the two holes may only partially meet (which results in reduced venting efficiency and increased likelihood of being clogged with material). In some cases, the mold may be shaped such that a high number of blind holes meet at a single location in the mold. This creates a single point of failure that may negatively affect a larger portion, if not the entire mold if that single location becomes clogged with material. Moreover, the thin holes associated with traditional manufacturing are prone to clogging failure, and even without clogging issues, the relatively narrow holes will slow the flow of liquid and/or gas during molding operations. Because of the foregoing issues, traditional manufacturing of a mold may include milling of material from the back side of the mold to follow the curvature of a first surface which creates a uniform thickness of the mold and may help eliminate issues associated with blind holes because any holes drilled through the first surface of the mold will intersect with a second surface of the mold which has been milled away. However, this creates additional problems associated with aforementioned air gaps between the second surface and a heating structure. For example, if the heating structure provides a flat pad, any portion of the mold that is milled away may not receive as much heat as another portion that actually makes contact with the heating structure.

[0053] In certain aspects, during the molding process, the first end 581 will contact a heating block (not shown) to transfer heat from the heating block to the first end 581 and then to the second end 582 so that the whole perforated structure 500 is heated. Accordingly, the first end 581 may include a (e.g., flat) surface conformal to the heating block to improve the heat transfer ability of each of the support structures 580. Heat may be transferred from the perforated structure 500 to the material mixture that has been applied to the first side 510 of the perforated structure 500. Thus, the thicker second end 582 of the support structure 580 may concentrate or accumulate more heat than the narrower first end 581.

[0054] FIGs. 6A and 6B illustrate different views of an example perforated structure 600 manufactured using an additive manufacturing process that can be used in both of the first and second exemplary molding processes described above. As illustrated, the perforations on a first side of the perforated structure 600 may connect to multiple channels within the body of the perforated structure 600, wherein the multiple channels form a woven pattern. It should be noted however, that any suitable pattern or arrangement of channels is contemplated by this disclosure, including synchronous channel patterns and asynchronous channel arrangements. [0055] FIG. 6A illustrates a top perspective view of a first side (e.g., a side of the perforated structure 600 upon which a material mixture is distributed) of a perforated structure 600. In this view, the first side of the perforated structure 600 is transparent, showing a first plurality of channels 620 that extend from and connect multiple perforations. This view also shows a second plurality of channels 630 that extend directly from second perforations 634. In this example, the first plurality of channels 620 and multiple perforations are located in a second zone 622 of the first side similar to the second zone 504 of the perforated structure illustrated in FIGs. 5A-5E. The second plurality of channels 630 and second perforations 634 are located in a first zone 632 of the first side similar to the first zone 502 of the perforated structure illustrated in FIGs. 5A-5E.

[0056] As illustrated, the first zone 632 is characterized by a circular area with a rim 636 separating the first zone 632 and the second zone 622. As discussed, the second plurality of channels 630 are defined by a first cross-sectional area that is narrower than a second cross- sectional area, giving the channel an appearance of a bottle with a relatively thinner neck at the first side. While the transition from the first cross sectional area to the second cross sectional area is generally illustrated as a smooth bottleneck-like transition, it should be noted that any suitable transition between the cross section areas is contemplated, including angled transitions (e.g., step or sawtooth transitions). Moreover, while the bottle shaped channels are generally illustrated as round or circular, any suitable shape is also contemplated (e.g., triangular and rectangular shaped channels). In certain regions of the first zone 632, the neck portion of channel the channel 630 is bent to accommodate different contours within the first region wherein a corresponding perforation is located on the contour. The rim 636 includes a continuous channel 638 that connects multiple perforations on the rim to other segments of channels within the body of the perforated structure.

[0057] Perforations in the second zone 622 may provide access to multiple segments. Here, a first perforation 624 provides access to a first segment 626a of a channel that has a perpendicular or angled connection to a second segment 626b of the channel. Thus, a perforation in the second zone 622 may provide access to the first segment 626a and the second segment 626b of the channel. It should be noted that a channel may comprise multiple branches and segments of different sizes and/or orientations that connect one or more perforations to the multiple segments. For example, a channel may be accessed from one or more perforations from one or more zones of the first side.

[0058] FIG. 6B illustrates detailed perspective view of the second zone 622 of FIG. 6A. As shown, the first perforation 624 provide access to the first segment 626a of a channel that has a perpendicular or angled connection to a second segment 626b of the channel. Here, multiple perforations are connected by a pattern of channel segments that provide the multiple perforations with access to a common channel end 650. The common channel end 650 is wider than the multiple segments leading up to it, to allow for hot gas/liquid displaced from the material mixture to escape from the perforated structure 600 through a second end opposite the first end. Although not shown, in some examples, a channel may provide a single perforation access to multiple channel ends. Accordingly, the number of perforations on the first side of the perforated structure 600 may be less than, equal to, or greater than the number of channel ends on the second side of the perforated structure 600.

[0059] FIGs. 7A and 7B illustrate different views of an example perforated structure manufactured using an additive manufacturing process that can be used in both of the first and second exemplary molding processes described above. For example, FIG. 7A illustrates a top perspective view and FIG. 7B illustrates a bottom perspective view, respectively, of a portion of a perforated structure 700. Similar to the perforated structure 500 of FIGs. 5A-5E and the perforated structure 600 of FIGs. 6 A and 6B, the perforated structure 700 of FIGs. 7 A and 7B includes a first side and a second side opposite the first side, as well as a first zone 702, a second zone 704, and a third zone 706.

[0060] FIG. 7A is a transparent view from the first side of the perforated structure 700. As shown, a first set of perforations 710 in the first zone 702 generally extend linearly through the body of the perforated structure 700 to the second side via a single channel. A second set of perforations 712 in the second zone 704 may be connected to a similar network of channel segments as those shown in FIGs. 6A and 6B. That is, multiple perforations may be channeled into a single exit or opening on the second side. A third set of perforations 714 in the third zone 706 generally extend linearly through the body of the perforated structure 700 to the second side via a single channel.

[0061] A first perforation 716 or opening in the first side of the third zone is shown as a small white circle. Other perforations in other zones in the first side may be shown similarly as small white circles or small black circles. A first corresponding exit 718 is illustrated as a larger circle around the first perforation. This is because, in this example, the first perforation 716 is relatively narrow compared to the first corresponding exit 718 which is relatively wider. [0062] Also shown in FIG. 7A are a series of lateral channels that run through the body of the perforated structure 700 and substantially perpendicular to the channels of the first zone 702 and third zones 706. Here, the series of lateral channels may include a first plurality of segments in the second zone 704 that converge into a main segment in the third zone that exits from the side of the body of the perforated structure 700. For example, main segment 720 exits from the side of the body of the perforated structure 700. In this example, the series of lateral channels may replace the support structures 580 of FIGs. 5A-5E.

[0063] FIG. 7B is a non-transparent view of the second side of the perforated structure 700. As shown, exits of the plurality of channels that extend from the first side to the second side are shown as an array of black and grey circles on the second side of the perforated structure 700. Small white dots in some of the circles indicate a relatively narrower opening or perforation in the first side. Accordingly, the channels have the bottle shape, wherein the exiting region of the channel is wider than the opening perforation on the first side. Here, the second side of the perforated structure 700 is characterized as having a flat base with the plurality of lateral channels carved into the flat base. Several of the channel exits occur entirely or in part of a lateral channel, while other channel exits are outside of a lateral channel. As discussed, the base of perforated structure 700 may not be flat in certain aspects, but may conformal to a surface of a heating block that is applied to the base of the perforated structure 700.

[0064] In this example, the flat base of the second side of the perforated structure 700 may contact a heating block (not shown) to transfer heat from the heating block to the flat base of the second side. The second side may then transfer heat throughout the whole perforated structure 700. In some examples, the heating block may be flat, such that when the flat base contacts the heating block, the lateral channels form half-cylinders (or any other suitable shape, such as half diamond, half octagon, or a rectangular or ovoid shape, etc.) for venting liquid and/or gas from the material mixture. This provides venting to exhaust from the sides of the perforated structure 700 like, for example, a heated iron. Alternatively, the heating block may include the same pattern of lateral channels (e.g., the lateral channels of the perforated structure may be mirrored on the heating block). In this example, the second side of the perforated structure 700 is aligned with the heating block so that the lateral channels on both the block and the structure match up. This allows for maximum venting of liquid and/or gas during molding and heating of the material mixture.

[0065] It should be noted that, similar to the perforated structure of FIGs. 5A-5E, 6A, and 6B, the conformal (e.g., flat) surface of the perforated structure 700 enhances heat transfer through the body of the perforated structure 700 by facilitating a predictable (e.g., even) distribution of heat applied to the second side of the perforated structure 700. Here, as with other perforated structures discussed herein, the conformal (e.g., flat) surface provides a basis for predictability of heat distribution throughout the perforated structure 700. This reduces complexity of design of the perforated structure to accommodate uniform or disparate heat transfer to the first side of the perforated structure. That is, the perforated structure 700 can be designed so that the material mixture can be heated evenly, or so that certain regions of the first side can be brought to different temperatures than other regions. [0066] It should be noted that variations in the size and density of openings in any of the perforated structures described herein may affect the heat transfer abilities of the perforated structure. For example, if a first zone has a higher density of openings on the first side than a second zone, then the first zone may have more open space, and heat transfer of the first zone will be slower than heat transfer of the second zone. In another example, if there is a lower density of openings in the first zone of the second side than on the first side of the same zone, then heat may transfer more slowly from the second side to the first side, as compared to a second zone in which the density of openings in the second side is equal to the density of openings in the first side. Accordingly, properties of heat transfer from the second side to the first side of a perforated structure may be by varying based on the number, size, shape, and/or density of openings. Similarly, heat transfer may be varied across different zones in a perforated structure by varying the same properties of the openings.

[0067] FIG. 8 is a flowchart of an example process 800 for producing a molded product using a perforated structure. The process 800 may be performed using any of the perforated structures described herein (e.g., perforated structures illustrated in FIGs. 5A-5E, 6A, 6B, 7A, or 7B).

[0068] At a first block 802, the process 800 includes distributing a material mixture over a first side of a perforated structure comprising a second side opposite the first side, the perforated structure further comprising a body separating the first side from the second side, wherein the first side defines a contoured surface and the second side defines a base conformal to a heat source surface.

[0069] At a second block 804, the process 800 includes compressing the material mixture between the first side and a press surface conformal to the first side to displace content from the material mixture via a plurality of channels formed in the body of the perforated structure, wherein one or more of the plurality of channels extend from the first side to the second side. [0070] At a third block 806, the process 800 includes separating the compressed material mixture from the first side of the perforated structure, the compressed material mixture forming the molded product.

[0071] In certain aspects, the process 800 includes heating the second side of the perforated structure while compressing the material mixture, wherein the second side defines a flat base of the perforated structure. [0072] In certain aspects, the process 800 includes compressing the material mixture between the first side and the press surface until a threshold amount of content is displaced from the material mixture.

[0073] In certain aspects, the first side defines a contoured surface, and wherein at least one of the plurality of channels follows a non-linear path through the body of the perforated structure.

[0074] In certain aspects, at least one of the plurality of channels connects two or more of the plurality of channels.

[0075] In certain aspects, the at least one of the plurality of channels is parallel to the second side.

[0076] In certain aspects, at least one of the plurality of channels comprises a first channel region and a second channel region, wherein a perimeter of the second channel region is greater relative to a perimeter of the first channel region.

[0077] In certain aspects, the perforated structure includes a plurality of perforations, wherein each of the plurality of perforations provide an opening in the first side connected to the one or more of the plurality of channels.

[0078] In certain aspects, a first perforation of the plurality of perforations provides an opening in the first side connected to a first channel and a second channel, the first channel links the first perforation to a second perforation, and the second channel links the first perforation to a third perforation.

[0079] In certain aspects, the perforated structure includes a first channel extending into the body of the perforated structure from a first perforation of the plurality of perforations, the first channel coupling the first perforation to a second channel and a third channel, wherein the second channel and the third channel extend from the body of the perforated structure to the opposite second surface, and wherein a perimeter of a region of each of the second channel and the third channel is greater relative to a perimeter of a region of the first channel.

[0080] In certain aspects, the perforated structure includes a plurality of lateral channels extending into the body of the perforated structure from an outside edge of the body, the outside edge separating the first side from the second side, wherein each of the lateral channels form perpendicular intersections with the one or more of the plurality of channels.

[0081] It should be noted that the perforated structures as disclosed herein may be built using additive manufacturing (AM) or three-dimensional (3D) printing techniques, according to certain embodiments. In some embodiments, a channel which extends between an A-side opening and a B-side opening in a perforated structure may be configured to be self-supporting during the AM process. For example, in conventional manufacturing and printing, there is a need for adding “supporting material/structures” during the printing surfaces. In one example, surfaces which are under an angle (compared to an X-Y Cartesian plane) of 30° or more, may require different types of scaffold-like structures to facilitate the printing process, because the heat and weight of the material can result in deformations. Thus, in conventional manufacturing and printing, when a structure is designed with a cavity formed in the structure, that cavity would be completely filled with a support material during the printing/manufacturing process to prevent deformation. However, structural material is often difficult to reach and/or remove after the printing and manufacturing of the designed structure. Accordingly, the perforated structures described herein define the shape of the holes and channels such that the perforated structure can be printed without any supporting material. For example, during the build, a channel may be oriented at an angle that is less than 30° relative to the build platform.

[0082] In certain embodiments, a support structure (e.g., support structure 580 in FIG. 5E) may provide a means for physical support of a portion of the perforated structure during the AM process. The support structure may provide a means for draining excess heat in layers during the AM process. Accordingly, a support structure may serve a first role of draining heat from the perforated structure while it is built, and a second role of transferring heat from the second side (e.g., second side 512 of FIGs. 5A-5E) to the first side (e.g., first side 510 of FIGs. 5A-5E) of the perforated structure when it is later used in a molding process.

[0083] As discussed, a pressing structure may be another example of the perforated structure described in the foregoing. For example, a pressing structure may have similar design features and structural characteristics of the perforated structures described above.

ADDITIONAL CONSIDERATIONS

[0084] Various embodiments disclosed herein provide for the use of a computer control system. A skilled artisan will readily appreciate that these embodiments may be implemented using numerous different types of computing devices, including both general purpose and/or special purpose computing system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use in connection with the embodiments set forth above may include, but are not limited to, personal computers, server computers, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments (e.g., networks, cloud computing systems, etc.) that include any of the above systems or devices, and the like. These devices may include stored instructions, which, when executed by a microprocessor in the computing device, cause the computer device to perform specified actions to carry out the instructions. As used herein, instructions refer to computer-implemented steps for processing information in the system. Instructions can be implemented in software, firmware or hardware and include any type of programmed step undertaken by components of the system.

[0085] A microprocessor may be any conventional general purpose single- or multi-chip microprocessor such as a Pentium® processor, a Pentium® Pro processor, a 8051 processor, a microprocessor without interlocked pipelined stages (MIPS®) processor, a Power PC® processor, or an Alpha® processor. In addition, the microprocessor may be any conventional special purpose microprocessor such as a digital signal processor or a graphics processor. The microprocessor typically has conventional address lines, conventional data lines, and one or more conventional control lines.

[0086] Aspects and embodiments of the inventions disclosed herein may be implemented as a method, apparatus or article of manufacture using standard programming or engineering techniques to produce software, firmware, hardware, or any combination thereof. The term "article of manufacture" as used herein refers to code or logic implemented in hardware or non- transitory computer readable media such as optical storage devices, and volatile or non-volatile memory devices or transitory computer readable media such as signals, carrier waves, etc. Such hardware may include, but is not limited to, field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), complex programmable logic devices (CPLDs), programmable logic arrays (PLAs), microprocessors, or other similar processing devices.

Claims

WHAT IS CLAIMED IS:

1. A perforated structure, comprising: a first side; a second side opposite the first side; a body separating the first side from the second side; and a plurality of channels formed in the body, one or more of the plurality of channels extending from the first side to the second side, wherein: the first side defines a contoured surface, and the second side defines a base conformal to a heat source surface.

2. The perforated structure of claim 1, wherein the base comprises a plurality of columns extending at least partially between the second side and the first side, wherein a first surface of each corresponding column forms the second side, and wherein a first column has a different length relative to a second column of the plurality of columns.

3. The perforated structure of claim 1, wherein at least one of the plurality of channels follows one or more of: a non-linear path; a path defined by a pattern of paths by other of the plurality of channels; or a path defined by a pattern of a plurality of perforations connected to the plurality of channels at the first side.

4. The perforated structure of claim 1, wherein at least one of the plurality of channels connects two or more of the plurality of channels.

5. The perforated structure of claim 4, wherein the at least one of the plurality of channels is parallel to the second side.

6. The perforated structure of claim 1, wherein: at least one of the plurality of channels comprises a first channel region and a second channel region, wherein a perimeter of the second channel region is greater relative to a perimeter of the first channel region; and the first channel region is connected to the second channel region by a third channel region characterized by an extension of the second channel region having a perimeter that is gradually tapered down to the perimeter of the first channel region.

7. The perforated structure of claim 1, further comprising a plurality of perforations, wherein each of the plurality of perforations provide an opening in the first side connected to the one or more of the plurality of channels.

8. The perforated structure of claim 7, wherein: a first perforation of the plurality of perforations provides the opening in the first side connected to a first channel and a second channel, the first channel links the first perforation to a second perforation, and the second channel links the first perforation to a third perforation.

9. The perforated structure of claim 7, further comprising a first channel extending into the body of the perforated structure from a first perforation of the plurality of perforations, the first channel coupling the first perforation to a second channel and a third channel, wherein the second channel and the third channel extend from the body of the perforated structure to the opposite second surface, and wherein a perimeter of a region of each of the second channel and the third channel is greater relative to a perimeter of a region of the first channel.

10. The perforated structure of claim 1, further comprising a plurality of lateral channels extending into the body of the perforated structure from an outside edge of the body, the outside edge separating the first side from the second side, wherein each of the lateral channels form perpendicular intersections with the one or more of the plurality of channels.

11. The perforated structure of claim 1, further comprising: a pressing structure comprising: a third side; a fourth side opposite the third side; a body separating the third side from the fourth side; and a plurality of channels formed in the body, one or more of the plurality of channels extending from the third side to the fourth side, wherein: the third side defines another contoured surface conformal to the contoured surface of the first side, and the fourth side defines a base surface.

12. A method for producing a molded product, the method comprising: distributing a material mixture over a first side of a perforated structure comprising a second side opposite the first side, the perforated structure further comprising a body separating the first side from the second side, wherein the first side defines a contoured surface and the second side defines a base conformal to a heat source surface; compressing the material mixture between the first side and a press surface conformal to the first side to displace content from the material mixture via a plurality of channels formed in the body of the perforated structure, wherein one or more of the plurality of channels extend from the first side to the second side; and separating the compressed material mixture from the first side of the perforated structure, the compressed material mixture forming the molded product.

13. The method of claim 12, further comprising heating the second side of the perforated structure while compressing the material mixture, wherein the second side comprises a plurality of columns extending at least partially between the second side and the first side, wherein a first surface of each corresponding column forms the second side, and wherein at least two columns have a different length from one another.

14. The method of claim 12, further comprising compressing the material mixture between the first side and the press surface until a threshold amount of content is displaced from the material mixture.

15. The method of claim 12, wherein at least one of the plurality of channels follows a non-linear path through the body of the perforated structure.

16. The method of claim 12, wherein at least one of the plurality of channels connects two or more of the plurality of channels.

17. The method of claim 16, wherein the at least one of the plurality of channels is parallel to the second side.

18. A method for generating a perforated structure, the method comprising: receiving a design of the perforated structure, the design indicating a shape, size, and position of the perforated structure relative to a build area corresponding to an additive manufacturing device, the design of the perforated structure defining: a first side; a second side opposite the first side; a body separating the first side from the second side; and a plurality of channels formed in the body, one or more of the plurality of channels extending from the first side to the second side, wherein the first side defines a contoured surface, and wherein the second side defines a base conformal to a heat source surface; and causing manufacturing of the perforated structure using additive manufacturing.

19. The method of claim 18, wherein the base comprises a plurality of columns extending at least partially between the second side and the first side, wherein a first surface of each corresponding column forms the second side, and wherein at least two columns have a different length from one another.

20. The method of claim 18, wherein at least one of the plurality of channels follows a non-linear path.

21. The method of claim 18, wherein at least one of the plurality of channels connects two or more of the plurality of channels, and wherein the at least one of the plurality of channels is parallel to the second side.

22. A pressing structure configured to mold a material mixture between a first side of the pressing structure and a contoured side of a perforated structure, the pressing structure comprising: a second side opposite the first side; a body separating the first side from the second side; and a plurality of channels formed in the body, one or more of the plurality of channels extending from the first side to the second side, wherein: the first side defines a contoured surface conformal to the contoured side of the perforated structure, and the second side defines a base of the pressing structure.

23. The pressing structure of claim 22, wherein the base comprises a plurality of columns extending at least partially between the second side and the first side, wherein a first surface of each corresponding column forms the second side, and wherein at least two columns have a different length from one another.

24. The pressing structure of claim 22, wherein at least one of the plurality of channels follows a non-linear path.

25. The pressing structure of claim 22, wherein at least one of the plurality of channels connects two or more of the plurality of channels.

26. The pressing structure of claim 25, wherein the at least one of the plurality of channels is parallel to the second side.

27. The pressing structure of claim 22, wherein: at least one of the plurality of channels comprises a first channel region and a second channel region, wherein a perimeter of the second channel region is greater relative to a perimeter of the first channel region; and the first channel region is connected to the second channel region by a third channel region characterized by an extension of the second channel region having a perimeter that is gradually tapered down to the perimeter of the first channel region.

28. The pressing structure of claim 22, further comprising a plurality of perforations, wherein each of the plurality of perforations provide an opening in the first side connected to the one or more of the plurality of channels.

29. The pressing structure of claim 28, wherein: a first perforation of the plurality of perforations provides the opening in the first side connected to a first channel and a second channel, the first channel links the first perforation to a second perforation, and the second channel links the first perforation to a third perforation.

30. The pressing structure of claim 28, further comprising a first channel extending into the body of the pressing structure from a first perforation of the plurality of perforations, the first channel coupling the first perforation to a second channel and a third channel, wherein the second channel and the third channel extend from the body of the pressing structure to the opposite second surface, and wherein a perimeter of a region of each of the second channel and the third channel is greater relative to a perimeter of a region of the first channel.

31. The pressing structure of claim 22, further comprising a plurality of lateral channels extending into the body of the pressing structure from an outside edge of the body, the outside edge separating the first side from the second side, wherein each of the lateral channels form perpendicular intersections with the one or more of the plurality of channels.