Molded fiber component production line using treatment-less molding and

Abstract

A method of producing a molded fibrous component includes drawing a fibrous slurry onto a forming mold to form a partially molded molded fibrous component. The forming mold includes a forming mold reference dimension along a first axis of the partially formed molded fibrous component. The partially shaped molded fibrous component is inserted into the stamper. The stamper includes a stamper reference dimension along a first axis of the partially formed molded fibrous component, where the stamper reference dimension is greater than the forming mold reference dimension. Compression pressure is applied to the partially shaped molded fibrous component with the stamper to expand the partially shaped molded fibrous component toward the stamper reference dimension.

Description

[0001] Cross - Reference to Related Applications

[0002] This application was filed as a PCT international application on March 16, 2023, and claims the benefit and priority of U.S. Application No. 63 / 321,378, filed on March 18, 2022, entitled "MOLDED FIBER PART PRODUCTION LINES USING TRIMLESS FORMING AND PRESSING MOLDS", the disclosure of which is hereby incorporated by reference in its entirety.

[0003] Introduction

[0004] Currently, pollution caused by single - use plastic containers and packaging materials is a recognized global problem. Replacing single - use packaging with biodegradable and compostable materials is considered a way to reduce plastic pollution. However, for new environmentally friendly alternatives to succeed, they must compete with existing plastic technologies they are intended to replace in terms of both cost and performance.

[0005] As a brief background, since 1930, molded pulp (also known as molded fiber) has been used to produce containers, trays, and other packaging. Pulp can be produced from recycled materials such as old newsprint and corrugated cardboard boxes, or directly from trees and other plant fibers. Today, molded pulp packaging is widely used in electronic products, household items, automotive parts, and medical products.

[0006] Molds are made by machining a metal tool into the mirror image shape (or of the finished part). Holes are drilled in the tool, and a screen is then attached to its surface. A vacuum is drawn through the holes while the screen prevents the pulp from clogging the holes. To produce a molded fiber part, the mold is immersed in a fiber slurry, then a pressure gradient is applied, and water is drawn out through the holes in the mold. Fibers from the slurry are collected on the screen, and after the fiber layer has formed the desired thickness, the mold with the molded fiber part is removed from the slurry. Then the molded fiber part is removed from the mold, and subsequent processing (e.g., shaping, heating, drying, top - coating, etc.) can be carried out.

[0007] Molded fiber packaging products are biodegradable and compostable. However, currently known fiber technologies are not suitable for food packaging, where food may come into contact with the packaging, especially meat and poultry containers, prepared foods, agricultural products, microwave - able food containers, and lids and cups for beverage containers. Summary of the Invention

[0008] In one aspect, the technology relates to a method for producing a molded fiber component, the method comprising: drawing a fiber slurry onto a forming mold to form a partially formed molded fiber component, wherein the forming mold includes a forming mold reference dimension along a first axis of the partially formed molded fiber component; inserting the partially formed molded fiber component into a compression mold, wherein the compression mold includes a heating element, and wherein the compression mold includes a compression mold target dimension along the first axis of the partially formed molded fiber component, wherein the compression mold target dimension is greater than the forming mold reference dimension; applying a compression pressure to the partially formed molded fiber component using the compression mold; applying an elevated temperature to the partially formed molded fiber component using the heating element, wherein the application of the compression pressure and the elevated temperature causes the partially formed molded fiber component to expand towards the target dimension of the compression mold, and substantially curing the partially formed molded fiber component into a molded fiber component; and removing the molded fiber component from the pressing. In an example, drawing the fiber slurry onto the forming mold includes: drawing the fiber slurry to a first depth substantially close to the entire forming mold; and drawing the fiber slurry to a second depth close to a predetermined region of the forming mold, wherein the second depth is greater than the first depth. In another example, the predetermined region is adjacent to the outer edge of the partially molded fiber component. In yet another example, the predetermined region is adjacent to an internal feature of the partially molded fiber component. In yet another example, the forming mold includes a porous surface adjacent to a forming mold reference direction, and wherein the porous surface extends away from the lowest surface of the forming mold, and wherein the fiber slurry is drawn onto the forming mold such that the depth at which the fiber slurry is drawn is greater than the depth of the fiber slurry adjacent to the lowest surface.

[0009] In another example of the above aspect, the porosity of the portion of the forming mold adjacent to the fiber slurry is greater than the porosity of the portion of the forming mold remote from the fiber slurry. In another example, drawing the fiber slurry onto the forming mold includes drawing the fiber slurry onto a screen placed adjacent to the forming mold. In another example, the compression mold target dimension is defined by the outermost periphery of the compression mold, and wherein the application of the compression pressure and the elevated temperature causes the partially formed molded fiber component to expand to contact the outermost periphery of the compression mold. In yet another example, the contact between the partially molded fiber component and the outermost periphery of the compression mold substantially surrounds the entire perimeter of the compression mold. In another example, the contact is characterized by the absence of fiber fronds. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Aspects of at least one example will be discussed below with reference to the accompanying drawings, which are not intended to be drawn to scale. The inclusion of the drawings is to provide illustration and further understanding of the aspects and examples, and the drawings are incorporated into and form a part of this specification, but are not intended as a definition of the limitations of a particular example. The drawings, together with the remainder of the specification, are used to explain the principles and operations of the described and claimed aspects and examples. In these drawings, each identical or nearly identical component shown in various drawings is represented by the same reference numeral. For clarity, not every component is labeled in every drawing.

[0011] Figure 1 A schematic diagram of an exemplary molded fiber component production line is shown.

[0012] Figure 2 An example of a molding station is shown.

[0013] Figure 3 A partial schematic view of the molding station and the component transfer system in mating engagement is shown.

[0014] Figure 4 Shows Figure 3 A partial schematic view of the molding die of the molding station of

[0015] Figure 4A and 4B Perspective views and a partially enlarged perspective view of the die for the molding station are shown respectively.

[0016] Figure 5 A perspective view of the pressing station is shown.

[0017] Figure 6 A partial schematic view of two dies of the pressing station in mating engagement is shown.

[0018] Figure 6A and 6B Partial schematic views of two dies of the pressing station during the pressing operation are shown.

[0019] Figure 7 A method for molding a molded fiber component is shown. Detailed Description

[0020] Before disclosing and describing improvements to a production line for manufacturing molded fiber products, it should be understood that the present disclosure is not limited to the specific structures, processing steps, or materials disclosed herein, but extends to equivalents recognized by those of ordinary skill in the relevant art. It should also be understood that the terms used herein are only for describing specific embodiments of the production line and its components and are not intended to be limiting. It must be noted that, unless the context clearly dictates otherwise, the singular forms "a," "an," and "the" as used in this specification include plural referents. Thus, for example, reference to "a step" can include multiple steps, and reference to the "production" or "manufacture" of a step or action should not be construed as all products.

[0021] Various embodiments of the techniques described below relate to the production of fiber-based or pulp-based products for both inside and outside the food and beverage industries. As a non-limiting example, the present disclosure relates to the automated, efficient, and high-speed production of fiber-based containers. Fiber-based products are suitable for replacing their corresponding plastic products in a variety of applications, such as: frozen, refrigerated, and non-refrigerated foods; medical, pharmaceutical, and biological applications; microwaveable food containers; beverages; edible and non-edible liquids; substances that release water, oil, and / or water vapor during storage, transportation, and preparation (such as cooking); horticultural applications including consumables and landscape / horticultural plants, flowers, herbs, shrubs, and trees; single-use or disposable storage and dispensing devices (such as paint trays, food trays, brush handles, shipping protectors); agricultural products (including human and animal foods such as fruits and vegetables); salads; prepared foods; packaging for meat, poultry, and fish; lids; cups; bottles; guides and dividers for processing and displaying the above; edge and corner pieces for packaging, storing, and transporting electronic products, mirrors, handicrafts, and other fragile components; buckets; pipes; industrial, automotive, marine, aerospace, and military components such as gaskets, washers, seals, liners, etc.; and related molds, wire mesh forms, formulations, processing, chemical formulations, tools, slurry dispensing, chemical monitoring, chemical injection, and their related systems, devices, methods, and technologies for producing the above components.

[0022] An existing production line for producing molded fiber components or products is described in Chinese Patent Application No. 201711129438.X, entitled "Flexible Production Line for Producing Pulp Molded Products" (hereinafter referred to as the "'438 Application"), the disclosure of which is hereby incorporated by reference in its entirety. The '438 Application generally describes a forming station that includes a former that creates a wet part by dipping a first mold into a fiber slurry tank, drawing fibers onto the mold until a desired amount of fibers is collected on a screen, and then removing the mold with the attached fiber layer from the slurry. In the system described in the '438 Application, the forming station also performs a forming operation on the wet part, where the first mold with the attached fiber layer is removed from the slurry and pressed into a second mold after removal. This forming operation removes some water from the wet part and contours the surface of the wet part opposite the first mold. In the production line of the '438 Application, after the molded fiber part is created at the forming station, it is then pressed at a pressing station. The pressing station can be multiple pressing stations operating in parallel. In one example in the '438 Application, four pressing stations are used. Each of the four pressing stations in the '438 Application includes a single pressing. The part is sent to a stacking station after pressing. The forming station, pressing station, and stacking station are arranged in a circle around a centrally located robot that controls an extendable robotic arm. The robot and the robotic arm are configured to remove the formed part from the forming station and transfer it to any of the four pressing stations. The robotic arm is also configured to remove the pressed part from any pressing station and transfer it to one of a different pressing station or the stacking station. Although the application describes many of the basic components and stations of a molded fiber part production line, unfortunately, the application shows many inefficiencies.

[0023] Other systems for producing molded fiber products are described in other documents. For example, systems showing multiple production lines, hot presses, forming stations, and other stations are described in PCT Application No. PCT / US2020 / 031675, entitled "SYSTEMS AND METHODS FOR PRODUCING MOLDED FIBER PRODUCTS", filed on May 6, 2020, and in PCT Application No. PCT / US2020 / 031667, entitled "MOLDED FIBER PART PRODUCTION LINES HAVING HIGH OUTPUT AND REDUCED CYCLE TIMES", filed on May 6, 2020, to improve the production of such parts. The disclosures of these two applications are hereby incorporated by reference in their entirety. For the purposes illustrated in this application, an example system that can benefit from the techniques described herein is described below in Figure 1 which can benefit from the techniques described herein.

[0024] Figure 1 FIG. 1 depicts a schematic view of an exemplary molded fiber component production line 100. The production line 100 is shown as having a plurality of stations and systems for moving partially formed and formed components between the various stations of the production line 100. Also shown herein are the various stations and systems, as well as the particular configuration of the production line 100 itself. The molding station 102 generally includes a molding die, a slurry tank, and an actuation system for moving the molding die relative to the slurry tank (typically by lowering the die into the slurry tank). For example, the molding station may be obtained from Nanya Pulp Molding Equipment Co., Ltd. in Guangzhou, China. The slurry tank includes a fiber slurry that includes wood fibers in a liquid. The molding die itself includes a plurality of vacuum channels connected to a vacuum source. The molding die may have a plurality of separate dies, typically for producing a plurality of identical fiber components, although molding dies for forming different components may also be contemplated. In an example, the molding die may include a die body or plate that includes the contours, features, etc. required for a particular product. The vacuum channels of the die body may have a designed path or layout within the die body, or may also be randomly formed in the die body as part of the die production process. Some die bodies may include a screen or mesh on which a surface is formed, and the fibers are stretched on this surface during the molding process. In use, the actuation system lowers the molding die into the slurry tank and activates the associated vacuum source. This operation draws the slurry liquid into the vacuum channels, causing the fibers to remain on the surface of the molding die or mesh (if any). When the desired amount of fibers has been drawn onto the surface or mesh, the actuation system raises the molding die out of the slurry. At this point in the process, the fibers disposed on the molding die are referred to herein as partially formed fiber components because they include the general contours and features of the finished molded fiber component, but do not exhibit the performance characteristics of the finished component.

[0025] The partially formed molded fiber component can then be removed from the forming mold for further processing. This operation can be performed by a component transfer system 104 that includes a component transfer feature, which can be a component transfer mold that is substantially corresponding or compatible with the forming mold. In this regard, the component transfer mold also performs the function of surface forming the partially molded fiber component, where the surface is arranged to be opposite to the surface of the forming mold that contacts the partially molded fiber component. The component transfer mold can also include or define a plurality of vacuum channels (as described above in the context of the forming mold) connected to a vacuum source. In use, the component transfer mold is positioned to contact the partially formed molded fiber component. This contact forms the opposing surface of the partially formed molded fiber component. After actuating the vacuum source, the partially formed molded fiber component is removed from the forming mold. The component transfer system 104 includes a transfer system that moves the component transfer mold from the forming station 102 to a downstream station, in this case the pressing station 106. In this regard, the forming station 102 and the pressing station 106 can form the ends of the movement range of the component transfer system 104, which can be referred to as the first position and the second position respectively in the example. Depending on the cycle times of the forming station 102 and the pressing station 106, the second position can be an intermediate waiting station where the component transfer feature can be positioned to wait for the pressing station 106 to become available.

[0026] Production line 100 includes a pressing station 106. The pressing station 106 substantially cures a partially formed molded fiber component into a molded fiber component (meeting the general performance requirements to be used) by a combination of compressive pressure and elevated temperature. A component transfer system 104 can transfer the partially formed fiber component to the pressing station 106 (as shown by arrow 112). The pressing station 106 includes two molds, commonly referred to as a core mold and a corresponding and compatible cavity mold. Whatever terminology is used, the core mold and the cavity mold are formed as two generally opposing surfaces of the molded fiber component. These two molds are generally similar in construction to the above-described forming mold and transfer mold to form the partially formed fiber component into a molded fiber component. Thus, the transfer 112 can be achieved by the component transfer features of the component transfer system 104 substantially matching either the core mold or the cavity mold. Vacuum channels can be formed in either or both of the core mold and the cavity mold and connected to a dedicated vacuum source. During the transfer 112, the vacuum source of the mold engaged with the transfer features can be activated to transfer the partially molded fiber component to the appropriate mold for pressing. Heating elements can be provided in either or both of the core mold and the cavity mold. The core mold and the cavity mold are moved relative to each other by a pressure actuation system (in the example, the pressure actuation system is a hydraulic press). As the pressure actuation system reduces the separation distance between the core mold and the cavity mold (with the partially formed fiber component therebetween), the increased compressive pressure helps to form the partially formed fiber component into a molded fiber component. The increased compressive pressure squeezes out additional liquid from the partially formed fiber component, and through one of a plurality of vacuum sources connected to the vacuum channels present in either or both of the core mold and the cavity mold, this liquid can be removed from the pressing station. Additionally, the elevated temperature generated by the heating elements helps to further form and dry the partially formed fiber component until a component more consistent with the molded fiber component is produced therefrom.

[0027] The removal system 114 removes the molded fiber components from the press station 106. The removal system can include a removal feature that includes a plurality of vacuum channels. The removal feature can be in the form of a removal mold that is configured to be compatible with either the core mold or the cavity mold. In such a case, the vacuum channels communicate with one or more ports on the surface of the removal mold such that vacuum pressure can suck the formed fiber component off of the core mold or the cavity mold. In another example, the removal feature can be a plurality of vacuum cups attached to the vacuum channels. The vacuum pressure applied to the channels by a vacuum source can also remove the formed fiber component from the core mold or the cavity mold. The removal system 114 includes a transfer mechanism that moves the removal feature from a position engaged with a particular mold at the press station to a downstream station. In such a case, the downstream station can be one or more of a scrap station 118, a printing station 122, a quality control station 124, and a stacking station 126, each of which will be described below.

[0028] The scrap station 118 is located downstream of the removal system 114. The scrap station 118 can include a system for capturing known or suspected unusable molded fiber components from the removal system and reintroducing those components into the slurry system. In an example, the scrap station can be a bin, chute, or other structure into which the components can be released from the removal system 114. In certain configurations, partial vacuum pressure can be released to discard damaged or other unwanted components into the scrap station 118.

[0029] After the scrap station 118, the molded fiber components are generally considered to be sufficiently formed for use. However, other downstream stations can be used to add graphics, logos, or other visual information to each molded fiber component, inspect the quality of the finished components, or stack or otherwise package the molded fiber components for delivery. Accordingly, a downstream printing station 122, a quality control station 124, and a stacking station 126 are depicted. These optional stations will also be described in more detail below.

[0030] The entire production line 100 can be automated and controlled by the illustrated control system 128. The control system 128 can be connected to each station, and even to subassemblies of each station, as well as to the transfer and removal systems (in the form of conveyors, robots, and other devices as described elsewhere herein), and control their operation. As discussed further below, the control system 128 can continuously monitor the operations and conditions on the production line 100 and adjust the operations to ensure the proper functioning and quality of the final components.

[0031] It is expected that control of all operating parameters will improve the quality of the formed fiber components and increase the throughput of production line 100. To obtain such control, a sensor network throughout production line 100 is envisioned. In an example, various sensors are provided at each station and on each conveyor system to monitor any relevant parameters of the operation of production line 100. Temperature control of the heated die of the pressing station is an example of such monitoring. Signals from these sensors can be sent to and processed by control system 128. As another example, the pressing station 106 can be dynamically controlled based on sensors in station 106. In other words, the pressing station 106 can be operated until a desired state is obtained in the formed fiber component. In an example, one of the dies in pressing station 106 can be provided with one or more sensors that directly or indirectly monitor the state of the formed fiber component. For example, temperature sensors can be provided on the die surface to monitor the temperature of the formed component at the location where it contacts the die. Similarly, pressure sensors, humidity sensors, light emitter / sensor pairs, conductance sensors, one or more electrodes that monitor current passing through the formed component, or any other such monitoring devices can be provided at one or more locations on the die. Based on the output of the sensors, the time allotted to press the formed component can be dynamically controlled by control system 128. For example, when a desired temperature (e.g., a predetermined temperature threshold) determined by the temperature sensor is reached, the pressing operation can be terminated.

[0032] Such monitoring sensors are not limited to being located in or on pressing station 106 and can be located anywhere in production line 100. In one example, the white water flow associated with forming station 102 can be monitored via one or more flow sensors. This allows the flow rate and volume of white water removed from the partially formed fiber component over time to be monitored at various stations throughout production line 100. This allows, for example, the pressing station to be controlled based on the water flow rate and volume observed during operation. When it is determined that the flow rate or volume has reached a predetermined threshold (e.g., the flow rate has decreased by 90% since the start of operation or after 10 ml of water has been collected from the component during the pressing operation), the pressing operation can be terminated regardless of how long the operation has taken.

[0033] Such monitoring data can also be used for other functions than controlling the run time of pressing station 106 or any other component. In an example, pressing station 106 can dynamically increase or decrease pressure based on the data collected. In this way, it is envisioned that any controlled operating parameter (e.g., pressing operation time, pressing pressure, die temperature, slurry temperature, vacuum pressure, slurry flow rate, slurry quality, mixing tank temperature, conveyor speed or temperature, dryer temperature, ink flow rate, or any other operating setting related to the time, temperature, pressure, or movement of components of the production line) can be controlled in response to data obtained from one or more sensors.

[0034] Figure 1 The production line 100 therein can be operated in a continuous mode. Various stations and component transfer systems can move continuously, and the components on the production line 100 are pressed, printed, and dried during movement. For example, as described herein, the quality control station can be a simple through-station through which the conveyor belt passes when testing components. The printing station can be one or more movable or fixed print heads that print on the components as the components pass beneath the print heads.

[0035] Other configurations are also possible. For example, it is possible to set a semi-continuous configuration in which one or more of the stations remove components from the production line 100 for a period of time and then replace them when the operation of the subsequent stations is completed. In different semi-continuous configurations, the component transfer system 104 can operate in a stop-start mode in which the component transfer system 104 moves a predetermined distance and stops according to a preset schedule. Using this method, each component moves between stations over time. In an example, one or more of the component transfer system 104 and the removal system 114 can have component transfer features in the form of a mold incorporated into the appropriate systems 102, 114 (e.g., the core mold described herein). The mold can provide reliable holding for the component during its moving processing. Then, the pressing station can have an external mold that receives the part when the component arrives at the station.

[0036] Figure 1 The production line 100 therein has several advantages. The production line has inherent scalability because multiple parallel pressing stations 106, waste stations 118, and other stations can operate synchronously, where the component transfer system 104 and the removal system 114 serve each station. In this parallel configuration, each in the parallel part can be referred to as a "sub-line". In another example, each of the parallel sub-lines can be dedicated to different customers with different printing requirements, finished product requirements (and thus different pressing and / or drying requirements). Additionally, as another example, multiple stacking stations 126 can stack the components of different customers separately in a simple automated manner. The parallel configuration of multiple sub-production lines increases the adaptability of the production line 100, that is, any one station in the sub-production line may fail without stopping the entire production line 100. Additional adaptability can be provided by including a second forming station 102. At any given time, different sub-lines can be stopped without affecting the operation of other sub-lines. Therefore, the sub-production line dedicated to a specific product can be not operated until the product is needed, which means that the time for re-assembly can be omitted.

[0037] Figure 2 An example of the forming station 200 is shown. Specifically, as Figure 2As shown, the molding station 200 includes a frame 211, on which a lower part 212 and an upper part 213 are provided. The upper part 213 includes a shuttle 231 (corresponding to the above-mentioned component transfer system in this case) having an actuating mechanism 233, which allows the lifting of the transfer feature (in this case the transfer die 232). A dedicated vacuum source fixed to the shuttle 231 is not visible in the figure. The cylindrical rotating shaft 223 is rotatably connected via a frame mounting bracket 228 to a middle part located between the lower part 212 and the upper part 213 of the frame 211. The rotation angle of the shaft 223 is less than 360°, and the cylindrical rotating shaft 223 can rotate back and forth. At both ends of the cylindrical rotating shaft 223 are elbows 226. Both ends of the rotating shaft 223 are fixed to the frame through rotating shaft seats, and gears 227 are respectively sleeved on both sides of the cylindrical rotating shaft 223, and on both sides of the middle part of the frame 211 are provided with translational connections with the gears 227. Two relatively symmetric molding dies 224a, 224b are attached to the cylindrical rotating shaft 223. In this example, the two dies 224a, 224b include a template 230 (only visible on the upper part 213), on which a core die is formed, and a screen is provided, and when the die is in the lower molding chamber 221 or the slurry tank, fibers are drawn onto the screen. In Figure 2 it, the lower die 224b is located in the slurry tank 221, and this position is called the molding position, and the relatively positioned upper die 224a faces upward towards the shuttle 231 and the transfer die (cavity die) 232 carried thereon.

[0038] The two core dies 224a, 224b are rigidly connected to the rotating shaft 223 through several tubes 225. These tubes 225 and the hollow shaft 223 are connected to a vacuum pump system. The tubes are also connected to through-pieces in the dies 224a, 224b. The vacuum pump system creates a pressure difference, pulling the slurry towards the die 224, so that fibers accumulate on the mesh surface of the die. As described above, the two core dies 224a, 224b are symmetric. This enables the two core dies to rotate around the axis of the rotating shaft 223 by rotating the shaft 223, so as to quickly move the die between the lower part 212 and the upper part 213. The fiber slurry bath is contained in the slurry tank 221. When the die 224 is located in the tank 221, as Figure 2As shown, when the slurry is drawn through the mold 224 by the vacuum pump system, fibers are deposited on the mold 224, thereby creating a partially formed fiber component (not shown) in the mold 224. In one example of the forming station 200, after an appropriate amount of fibers are drawn onto the mold 224 and reach the desired thickness, the slurry tank 221 is lowered from the mold 224 by an actuating system in the form of a vertical lift 222, such that the mold 224 is free to move to the upper part 213 position. Then, the mold 224 and the partially formed fiber component can be rotated to the position of the upper part 213. The upper part 213 includes a transfer mold 232 attached to an actuating mechanism 233. Activating the mechanism 233 causes the transfer mold 232 to press against the upward-facing lower mold 224a. The mechanism 233 can include one or more of a hydraulic cylinder, a servo motor, a pneumatic cylinder, or any other known lifting device. By pressing the mold 224 and the mold 232 together, water can be drained from the partially formed fiber component and collected through the inner mold 224 via the shaft 223. After the pressing operation is completed, suction is applied to the partially formed fiber component through the through-hole in the mold 232, and the mold 232 retracts onto the shuttle 231 through the mechanism 233 to move to the downstream station. This allows the mold 224 to be rotated to the lower part 212 to repeat the entire forming process.

[0039] In the example, the pressing operation performed by the transfer mold 232 operates at a selected pressure for a fixed time that is equal to the time it takes for the forming component to be drawn onto the mold at the lower part 212. In an alternative embodiment described in more detail below, the pressing time is dynamically controlled based on monitoring data from sensors at one or more locations on the upper part 213. In an alternative example of the forming station 200, the slurry tank 221 can also include a movable outer mold (not shown) in the tank 221. In this embodiment, after the fibers in the slurry are drawn onto the mold 224, the outer mold can be pressed against the mold 224 in the slurry tank 221. This provides an additional pressing operation for the partially formed fiber component, such that the component leaving the former 200 will undergo two pressing operations instead of just one pressing operation as in the previous example. In any case, after the partially formed fiber component is created by the transfer mold 232 and removed from the inner mold 224, the shuttle 231 transfers it to another station in the production line. In another example, the transfer mold 232 can be located at the end of a robotic arm that extends into the upper part 213 and receives the component when the suction on the partially formed fiber component by the transfer mold 232 is activated. This is just one example of how component transfer can be implemented by a robotic arm. Many such methods and systems are known in the art, and any suitable method and mechanism can be used for the forming station 200, the robotic arm, or any other component of the production line described herein.

[0040] Figure 3A partial schematic view of a molding station and a component transfer system in mating engagement 300 is shown. The molding station 302 includes a molding die 304, in this case a core die configuration. As used herein, the term "core die" refers to a die having features that project substantially away from the mold plate to form a "core" around which the fibrous component 306 is at least partially disposed. The component transfer system 308 includes component transfer features, in this case in the form of a component transfer die having a cavity die configuration. As used herein, the term "cavity die" refers to a die having features that project substantially inwardly into the mold plate to form a "cavity" such that the fibrous component 306 and the core die extend into the cavity. Each of the molding die 304 and the component transfer die 310 defines at least one (but typically multiple) of the vacuum channels 312. Each vacuum channel 312 is connected to a dedicated vacuum source 314, the function of which is as described above. It should be noted that a similar mating engagement is used when the removal system (as described above) engages the die of the press station.

[0041] Figure 4 A partial schematic view of a molding die 400 of a molding station 300 that can be used for Figure 3 is shown. The molding die 400 can correspond to (with respect to location and general operation) Figure 3 the molding die 304 shown in. Molding dies of various configurations are known in the art. For example, a molding die made of a solid core can be used. Such a solid core molding die can include a screen or mesh material disposed on its die surface. The screen or mesh material provides a substrate onto which the fiber slurry can be drawn during the molding operation while ideally distributing the vacuum pressure according to the needs or desires of a particular application or component. In Figure 4In [the context], the forming mold 400 can be made of 3D printing materials or other materials that can provide structural integrity while customizing the porosity therein (and thus the amount of vacuum that can be drawn through the mold for collecting fiber slurry thereon). Such systems and methods incorporating 3D printed forming molds are described in PCT Application No. PCT / US2021 / 052731, titled "POROUS MOLDS FOR MOLDED FIBER PART MANUFACTURING AND METHOD FOR ADDITIVE MANUFACTURING OF SAME", filed on September 29, 2021, the disclosure of which is hereby incorporated by reference in its entirety. The mold 400 can include regions 420 with a relatively large porosity (e.g., adjacent to the regions where fiber clusters 424 can be drawn) or regions 422 with a relatively small porosity (e.g., near the exterior of the mold 400), which ultimately control the amount of vacuum drawn from certain regions of the mold 400. In the example shown, the mold volume 420 with a relatively large porosity is shown as having a hexagonal or honeycomb cross-section, while the volume 422 with a relatively small porosity is shaded. As shown, the porous portions 420 are interconnected and are generally disposed below the location on the mold 400 where the fiber slurry 424 will be drawn onto the mold 400. Additionally, the porous portions 420 can extend upward along the dam walls 426 or the sides of the forming mold 400, typically to the maximum height shown. In this configuration, the fiber slurry 424 is drawn toward both the lower surface of the forming mold 400 and the sides of the forming mold 400. By drawing the slurry 424 toward the sides of the mold 400, excess slurry 428 may accumulate and adhere to the sides and move upward along the sides. The excess slurry 428 collected on the sides is then utilized in subsequent processing to form clean edges of the formed fiber components made with the disclosed techniques.

[0042] When measured from the common lowest point of the mold 400, the slurry 424 can be drawn to a first depth that is substantially close to the entire mold 400. This depth can be the depth required to produce a molded fiber product with a desired nominal thickness. However, near certain regions of the mold 400, the slurry 424 can be drawn to a second depth (again measured from the common lowest point of the mold 400) in order to be able to form clean edges as described herein. Generally, in order to draw the slurry 424 to a higher height at certain locations, it is desirable to draw the slurry 424 onto one or more substantially vertical surfaces. These surfaces can be near the sides of the mold 400 or adjacent to certain internal features.

[0043] As described herein, the techniques described herein are capable of forming molded components with sharp edges without the need to trim excess material that the molded components may exude outward from the hot press during the pressing operation.

[0044] In one example, the formed dimensions of a partially formed molded fiber component 424 (e.g., formed in a forming mold 400) are typically smaller than the formed dimensions of the finished molded fiber component (when exiting the hot press, as described below). Referring Figure 4 to, the forming mold 400 can be described as having a forming mold reference dimension D REF , for illustrative purposes, as Figure 4 shown in REF , the dimension D REF width can be 82.0 cm. Since the various molded fiber components formed using the techniques described herein can take any desired shape, the reference dimension D REF is determined relative to a predetermined first axis of the formed fiber component itself. For example, if the molded fiber component 424 has a substantially square shape, the predetermined first axis can extend from one corner through the center and to the opposite corner. If the molded fiber component is approximately circular (e.g., oval or partially oval), the predetermined first axis can correspond to the major axis or minor axis as understood in the art. In another example, the predetermined first axis can correspond to the diameter of a molded fiber component having a circular configuration. In summary, the predetermined first axis is along a known axis of the product such that when the component is in a partially formed production stage, when it is removed from the forming mold, the part dimensions along that axis are known. For illustrative purposes, the target dimension D TAR of the finished formed fiber component (e.g., after the pressing operation described below) is also shown, and when the component exits the forming mold 400 as a partially formed formed fiber component, it is ultimately larger (e.g., 84.0 cm) along the predetermined first axis of the formed dimension. In order to enable the fiber component 424 to extend while still maintaining sharp edges during the pressing operation, additional material (e.g., excess slurry 428) is collected at the positions where sharp edges are desired when the fiber slurry is collected in the forming mold. As shown, these positions can be near the outer edge of the fiber component or at internal openings. The additional material 428 collected at specific positions during the forming stage is pressed in a controlled manner during the subsequent pressing operation to form sharp edges on the features in the mold. Figure 4 Additional slurry 428 collected at the outer edge of the component is shown, but it can also be collected near internal locations such as Figure 4 the porous column 430 shown in

[0045] Figure 4A and 4B show a perspective view and a partially enlarged perspective view of the forming mold 400 for a pressing station, respectively. Figure 4A and 4Bis also described and shows a method of collecting additional fiber slurry at a desired location. The forming die 400 (shown inverted in Figure 4A and 4B ) is formed from a machined integral part 402 or a porous molded integral part, both of which are covered with a mesh material (not shown) to prevent the fiber slurry from being drawn onto the die itself. If a machined integral part is used, a plurality of vacuum channels formed in the part 402 can be communicatively coupled to ports 410 on the surface of the cavity 404 to draw the fiber slurry onto the mesh under vacuum during the forming operation. As described above, the forming die 400 can also be formed from a more porous material at locations where it is desired to collect the fiber slurry. One such location can be the perimeter wall or wall dam 406, which defines the outermost periphery of the cavity 404.

[0046] As described above, the forming die 400 can be configured such that the fiber slurry is drawn higher along the wall dam 406. By drawing the fiber slurry higher along the wall dam 406, during the pressing operation, excess fibers can more easily fill the larger gaps at the outer periphery of the mold. In an example, the forming die 400 can be configured to draw the fiber slurry to levels A, B, or C as shown in Figure 4 . For example, the wall dam 406 can be more porous until the desired level is reached. The formed fiber component typically has a nominal thickness required for a particular application of the component. In one example, the fiber thickness desired for a sharp edge will be thicker than the nominal thickness of the fibers drawn onto the forming die. However, during the pressing operation, the component itself and the desired sharp edge portion of the component will be compressed to the same nominal finished thickness, which is less than the thickness of the slurry during the forming process, whether at the edge or elsewhere. In another example, the fiber slurry can be drawn onto a portion of the forming die that is angled relative to its adjacent surface. The angle can be greater than 0°, for example, about 5°, about 10°, about 15°, about 20°, about 25°, about 30°, about 35°, about 40°, about 45°, about 50°, about 55°, about 60°, about 65°, about 70°, about 75°, about 80°, about 85°, about 90°, or within the range defined by the above angles. The angled surface can extend vertically above or below the adjacent surface. This results in a larger volume of slurry that can be pressed into a smooth edge during the pressing operation. For illustrative purposes, it should be noted that Figure 4 the angled surface in

[0047] Figure 5A perspective view of the press station 500 is shown. The station 500 includes a pressing mechanism 502, which includes an upper die 506 and a mating lower die 508. In this case, the lower die 508 is referred to as a core die because of the protruding feature 516 that forms the forming core of the molded fiber component. In contrast, the upper die 506 is referred to as a cavity die because a cavity is formed therein to receive the protruding feature 516 and the molded fiber component during the pressing operation. In other examples, the positions of the core die and the cavity die may be reversed. The upper die 506 and the lower die 508 may include one or more individual plates for forming a specific molded packaging product. In the example shown, six plates are used in the upper die 506 and the lower die 508 respectively, but other numbers of dies are also conceivable. By using multiple plates for each die, the throughput of the production line is increased. In this example, the press station 500 has six plates, but one, two, four, eight, ten or more plates may also be used. Although an odd number of plates may be used, an even number of plates is more common. This increases the throughput of the press station 500 (and other stations within the production line) within only the range where the equipment cost increment increases.

[0048] The pressing mechanism 502 is supported on a fixed base 510. The pressing mechanism 502 includes a movable plate 512 fixed to the upper die 506. The movable plate 512 is configured to slide along a plurality of tracks 515 when actuated by a piston 516. Actuation of the piston 516 drives the movable plate 512 (with the upper die 506 thereon) towards the base 510. A single pressurized fluid chamber 518 may be connected to the piston 516 through a tube 520, valves and other known elements. The controller 522 may be programmable and may be communicatively coupled to the controller of a robot (not shown) or a shuttle that forms part of a production line (not shown) to control the station 500 according to the needs or expectations of a specific application. In an application, either or both of the upper die 506 and the lower die 508 may be heated to properly mold the molded fiber product. Such heating elements are described elsewhere in this application.

[0049] Figure 6 A partial schematic view of two dies in mating engagement of the press station 600 is shown. The press station 600 includes a lower die 602, configured as a core die in this case. The upper die 604 is in the form of a component transfer die with a cavity configuration. The terms "core die" and "cavity die" are as described above. A fiber component 606 is disposed between the lower die 602 and the upper die 604. Each of the lower die 602 and the upper die 604 defines at least one (but typically multiple) vacuum channels 608. Each vacuum channel 608 is connected to a dedicated vacuum source 610, the function of which is as described above. In other examples, the lower die 602 and the upper die 604 may be made of materials such as those described above in Figure 4formed from the porous material described in the context. Each of the lower die 602 and the upper die 604 includes a heating element 612. In the case of the dedicated pressing station 600, elements 602 to 612 are used.

[0050] Improved temperature control during operation of the pressing station 600 is expected to improve the quality of the formed fiber components and increase the production rate of the production line. In one example, each die 602, 604 is provided with an internal heating element 612. The element 612 can be a simple internal channel through which a heated fluid can flow. In an alternative example, a resistance heater can be built into each die 602, 604. The heating element 612 is known in the art and any suitable heating technology, existing or developed later, can be used. Examples of heating the dies 602, 604 can also be provided with one or more temperature sensors T. The temperature sensors T can monitor the temperature in the dies 602, 604, the temperature of the surfaces of the dies 602, 604, the temperature of the fiber component 606, or the temperature at any location in, on, or near the dies 602, 604. In addition, for more precise temperature control, the dies 602, 604 can be divided into multiple segments or zones, and the temperature in each segment can be independently monitored and controlled.

[0051] Previous solutions for forming a clean edge on the molded fiber component included using additional trimming components in the pressing station 600 (such as Figure 6 the so-called "combined pressing and trimming station" shown) or in a dedicated trimming station (not shown). In the combined pressing and trimming station 600a, elements 602 to 612 are still used, but the trimmer 614 can also be used in combination with either or both of the lower die 602 and the upper die 604. The trimmer 614 can be a discrete element such as in the example shown. When the lower die 602 and the upper die 604 are in compressive contact, the outer edge of the molded fiber component 606 is pressed outwards. If not controlled, this can result in a "feathery" appearance at the edge where the fiber slurry randomly spills out of the die, resulting in an uneven edge. Therefore, the trimmer 614 is configured to press down on this feathery material, thereby cutting or piercing any material disposed outside a predetermined portion of the dies 602, 604. This separates the waste trim from the molded fiber component 606. However, such systems using mechanical trimmers have some drawbacks. The portion cut from the molded fiber component 606 may become trapped in the press die, which can affect subsequent components formed in the pressing station 600a. During the pressing operation, the slurry material is heated such that the slurry material effectively melts at the surface where the material of the component contacts the hot press, thereby forming a seal resistant to moisture penetration. Post-pressing trimming may break this seal, thereby exposing the component to penetration and reducing performance.

[0052] Therefore, the techniques described herein are related toFigure 4 In combination with the forming die, a pressing station is envisioned that has dimensions such that it can press a partially formed molded fiber component that expands to its maximum desired size while maintaining its structural integrity. This is described in Figure 6A and 6B which shows a partial schematic view of the lower die 652 and the upper die 654 of the pressing station 650 during a pressing operation. As Figure 6A shown, the partially formed molded fiber component 656 is first placed within the lower die 652. The target finished size or dimension D TAR corresponds to the finished size of the molded fiber component after the pressing operation, which is defined by the outermost periphery of the mold. The elevated temperature and compressive pressure applied by the mold create contact between the fiber slurry and substantially the entire perimeter or outermost periphery of the mold. It can be seen that this target finished size or dimension D TAR is larger than the size of the partially formed molded fiber component 656 removed from the mold. This target finished size or dimension D TAR is also measured along the same predetermined first axis as identified above with reference to Figure 4 Simply put, the lower die 652 is larger in size than the Figure 4 forming die. The upper die 654 forms a tight fit with the lower die 652 to restrict leakage of the material of the partially formed fiber component during the pressing operation. As the upper die 654 is lowered and the pressing operation is performed, the higher portions of the material near the edge (as Figure 4 shown, formed near the edge of the forming die) are pressed into the gap or void initially present between the partially formed fiber component and the lower die 652 to spread the material into and to the greatest extent possible within the lower die 652, thereby forming the finished component 658. Thereafter, the lower die 652 and the upper die 654 can be disengaged and the molded fiber component can be removed from the pressing station.

[0053] Figure 7A method 700 of forming a molded fiber component is shown. Method 700 begins at operation 702, where a fiber slurry is drawn onto a forming mold to form a partially formed molded fiber component. The forming mold includes a forming mold reference dimension along a first axis of the partially formed molded fiber component. The method continues with operation 704, where the partially formed molded fiber component is inserted into a compression mold. As described elsewhere herein, the compression mold has a heating element and a compression mold reference dimension along the first axis of the partially formed molded fiber component. The compression mold reference dimension is greater than the forming mold reference dimension such that when the compression pressure is applied to the partially formed molded fiber component using the compression mold, the partially formed molded fiber component extends toward the compression mold reference dimension (operation 706). At the same time, an elevated temperature is applied to the partially formed molded fiber component using the heating element (operation 708). This elevated temperature substantially cures the partially formed molded fiber component into a molded fiber component. Thereafter, the molded fiber component can be removed from the press, i.e., operation 710.

[0054] In an alternative example of method 700 described above, other optional operations can be performed. For example, drawing the fiber slurry onto the forming mold can contemplate drawing the fiber slurry to a first depth that is substantially close to the entire forming mold while drawing the fiber slurry to a second depth that is close to a predetermined region of the forming mold, where the second depth is greater than the first depth. In an example, the predetermined region is adjacent to the outer edge of the partially molded fiber component, but in other examples, e.g., in the case where a through-hole is desired in the molded fiber component, the predetermined region is adjacent to an internal feature of the partially molded fiber component. In another example, the forming mold includes a porous surface adjacent to a forming mold reference direction and the porous surface extends from the lowest surface of the forming mold. In this configuration, drawing the fiber slurry onto the forming mold causes the fiber slurry to be drawn to a depth that is greater than the depth of the fiber slurry adjacent to the lowest surface.

[0055] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties (such as molecular weight, reaction conditions, etc.) used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and the appended claims are approximations that may vary depending upon the desired properties sought.

[0056] Although the numerical ranges and parameters setting forth the broad scope of the technology are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviations found in their respective testing measurements.

[0057] Obviously, the systems and methods described herein are well suited to achieve the above objects and advantages, as well as those inherent therein. Those skilled in the art will recognize that the methods and systems in this specification can be implemented in a variety of ways and are thus not limited by the above exemplary embodiments and examples. In this regard, any number of features of the different embodiments described herein can be combined into a single embodiment, and alternative embodiments with fewer or more than all of the features described herein are possible.

[0058] While various embodiments have been described for the purposes of this disclosure, various changes and modifications can be made to them, which are fully within the scope contemplated by this disclosure. Many other changes can readily be envisioned by those skilled in the art, and these changes are encompassed within the spirit of this disclosure.

Claims

1. A method of producing a molded fiber component, the method comprising: drawing a fiber slurry onto a forming mold to form a partially formed molded fiber component, wherein the forming mold includes a forming mold reference dimension along a first axis of the partially formed molded fiber component; inserting the partially formed molded fiber component into a compression mold, wherein the compression mold includes a heating element, and wherein the compression mold includes a compression mold target dimension along the first axis of the partially formed molded fiber component, wherein the compression mold target dimension is greater than the forming mold reference dimension; applying a compression pressure to the partially formed molded fiber component using the compression mold; applying an elevated temperature to the partially formed molded fiber component using the heating element, wherein the application of the compression pressure and the elevated temperature causes the partially formed molded fiber component to expand towards the compression mold target dimension and substantially cures the partially formed molded fiber component into the molded fiber component; and removing the molded fiber component from the compression mold.

2. The method according to claim 1, wherein drawing the fiber slurry onto the forming mold includes: drawing the fiber slurry to a first depth substantially close to the entire forming mold; and drawing the fiber slurry to a second depth close to a predetermined region of the forming mold, wherein the second depth is greater than the first depth.

3. The method according to claim 2, wherein the predetermined region is adjacent to the outer edge of the partially molded fiber component.

4. The method according to claim 2, wherein the predetermined region is adjacent to an internal feature of the partially molded fiber component.

5. The method according to claim 2, wherein the forming mold includes a porous surface adjacent to a forming mold reference direction, and wherein the porous surface extends away from the lowest surface of the forming mold, and wherein drawing the fiber slurry onto the forming mold causes the fiber slurry to be drawn to a depth greater than the depth of the fiber slurry adjacent to the lowest surface.

6. The method according to claim 1, wherein the portion of the forming mold adjacent to the fiber slurry has a porosity greater than the portion of the forming mold remote from the fiber slurry.

7. The method according to claim 1, wherein drawing the fiber slurry onto the forming mold includes drawing the fiber slurry onto a screen placed adjacent to the forming mold.

8. The method according to claim 1, wherein the compression mold target dimension is defined by the outermost periphery of the compression mold, and wherein the application of the compression pressure and the elevated temperature causes the partially formed molded fiber component to expand to contact the outermost periphery of the compression mold.

9. The method according to claim 8, wherein the contact between the partially molded fiber component and the outermost periphery of the compression mold substantially surrounds the entire perimeter of the compression mold.

10. The method according to claim 1, wherein the contact is characterized by the absence of fiber fronds.

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