FIBER MOLDING SYSTEM AND METHOD

Abstract

A wet press for forming molded fiber products includes a slurry tank for holding a pulp slurry, and a forming platen for holding a forming die having a porous forming surface. The forming platen is movable between a dipping position proximate the tank and a pressing position spaced apart from the dipping position. The wet press further includes a transfer platen for holding transfer tooling having a first transfer face and a second transfer face. The transfer platen is movable for selectively positioning each of the first transfer face and the second transfer face in alignment with the forming platen when the forming platen is in the pressing position.

Description

The present application is a continuation of International Application No. PCT/CA 2024/051145, filed on Sep. 3, 2024, which claims the benefit of priority from co-pending U.S. provisional patent application No. 63/580,169, filed on Sep. 1, 2023, the entire contents of which are incorporated herein by reference in the entirety.

FIELD

The teaching disclosed herein relates generally to systems and methods for producing molded fiber articles, and specifically, to pulp fiber molding systems and methods including a vertically oriented wet press.

INTRODUCTION

U.S. Pat. No. 6,716,319 (Gale) discloses an apparatus for producing a molded pulp product from a fiber slurry comprising a dip tank containing a fiber slurry therein and having a liquid level. A platen is provided. A porous mold is carried by the platen. The platen and the mold carried thereby are lowered into the fiber slurry in a downward direction with the platen being disposed upwardly of the mold so that the mold is introduced through the liquid level into the fiber slurry. A vacuum is supplied to the platen and to the mold while the mold is disposed in the fiber slurry to cause fibers in the fiber slurry to collect onto the mold and form a wet molded pulp product. The platen and the mold with the wet molded product thereon are moved out of the fiber slurry through the liquid level to permit water to drain from the mold and the wet molded pulp product. The wet molded pulp product is then dried.

• • U.S. Pat. No. 11,479,919 (Parker) discloses contoured articles formed in a mold from a fiber slurry. The articles comprise a blend of cellulose fibers and cellulose ester, such as cellulose ester staple fibers. The articles are described as being suitable in a wide array of end uses, including as cups, lids, boxes or pouches, storage containers, trays, plates, food trays, cutlery, coffee cups, coffee cup lid, packaging, bowls, clam shells, bottle caps, straws, covers, and packaging inserts.

U.S. Pat. Appn. Publication No. 2022/0388201 (Knoll) discloses a first molding station for the partial-molding and pre-molding of molded parts made of fibrous material, a fiber molding system with such a first molding station and a method for operating this first molding station or the fiber molding system, and a molded part produced using such a method.

U.S. Pat. Appn. Publication No. 2023/0243107 (Hagenauer) discloses a fiber-forming process in a fiber-forming system having a molding station for molding, a preforming station for preforming, a hot-pressing station for final shaping a formed part made of environmentally-friendly-degradable fiber material. The fiber-forming system produces the formed part having the above stations by means of the method performed in the fiber-forming system as a fiber-forming process.

SUMMARY

The following summary is intended to introduce the reader to various aspects of the applicant's teaching, but not to define any invention.

According to some aspects of the teaching disclosed herein, a wet press for forming molded fiber articles includes a slurry tank for holding a pulp slurry, a forming platen for holding a forming die having a porous forming surface, the forming platen movable between a dipping position proximate the tank and a pressing position spaced apart from the dipping position, and a transfer platen for holding transfer tooling having a first transfer face and a second transfer face, the transfer platen movable for selectively positioning each of the first transfer face and the second transfer face in alignment with the forming platen when the forming platen is in the pressing position.

In some examples, the wet press further includes a brake coupled to the forming platen for locking the forming platen in the pressing position when the brake is in an engaged position, and a pressing actuator coupled to the transfer platen for pressing the transfer platen towards the forming platen when locked in the pressing position.

In some examples, the brake is biased to the engaged position when unenergized, and movable to a disengaged position when energized.

In some examples, the transfer platen has a first transfer die mounting surface for supporting a first transfer die of the transfer tooling and a second transfer die mounting surface for supporting a second transfer die of the transfer tooling, wherein the first and second transfer die mounting surfaces are positioned on opposite sides of the transfer platen.

In some examples, the transfer platen is rotatable about a transfer platen axis between a first rotational position for positioning the first transfer tool in alignment with the forming surface and a second rotational position for positioning the second transfer die in alignment with the forming surface.

In some examples, the forming platen is rotatable about a forming platen axis when moving between the dipping position and the pressing position.

In some examples, the wet press further includes a vacuum source for selective fluid communication with the porous forming face, and for selective communication with first apertures in the first transfer die and second apertures in the second transfer die.

In some examples, the vacuum source is separately controllable for independently providing fluid communication with the first apertures of the first transfer die and the second apertures of the second transfer die.

In some examples, the transfer platen is positioned vertically above the forming platen when the forming platen is in the dipping position and in the pressing position.

In some examples, the forming platen and the transfer platen are each translatable along a vertical press axis.

According to some aspects of the teaching disclosed herein, a method for supplying wet pressed molded fiber articles to a dry press includes moving a forming platen to dip a forming face of a forming die secured thereto into a slurry tank and deposit a first fiber mat on a porous forming surface of the forming face. In some examples, the method includes moving the forming platen to a pressing position, wherein the forming platen is rotated about a first horizontal axis to direct the forming face upwards, and pressing a first transfer die of transfer tooling mounted to the transfer platen against the first fiber mat on the forming platen when the forming platen is in the pressing position. In some examples, the transfer platen has a second transfer die opposite the first transfer die, and the method includes transferring the first fiber mat from retained engagement on the forming platen to retained engagement on the first transfer die, and rotating the transfer platen about a second horizontal axis to direct the first transfer die upwards and the second transfer die downwards. In some examples, the method includes moving the forming platen proximate the slurry tank, wherein the forming platen is rotated about the first horizontal axis to direct the forming face downwards, and dipping the forming face in the slurry tank, to deposit a second fiber mat on the porous forming surface of the forming face. In some examples, the method includes moving the forming platen to the pressing position, wherein the forming platen is rotated about the first horizontal axis to direct the forming face upwards, and pressing the second transfer die of the transfer tooling mounted to the transfer platen against the second fiber mat on the forming platen when the forming platen is in the pressing position. In some examples, the method includes transferring the second fiber mat from retained engagement on the forming face to retained engagement on the second transfer die, and transferring the first fiber mat and the second fiber mat from the transfer tooling to first and second press stations of the dry press.

In some examples, the porous forming surface of the forming face is in fluid communication with a forming vacuum source for at least a first forming time period to deposit and retain the first fiber mat on the forming face and remove moisture from the first fiber mat, and, a second forming time period to deposit and retain the second fiber mat on the forming face and remove moisture from the second fiber mat.

In some examples, the first forming time period is equal to the second forming time period.

In some examples, the first transfer die is in fluid communication with a first transfer vacuum source for a first transfer time period for removing moisture from the first fiber mat and retaining the first fiber mat on the first transfer die.

In some examples, the second transfer die is in fluid communication with a second transfer vacuum source for a second transfer time period, for removing moisture from the second fiber mat and retaining the second fiber mat on the second transfer tooling.

In some examples, the first transfer time period is equal to the second transfer time period.

In some examples, the first transfer die is maintained in fluid communication with the first transfer vacuum source for an extension time period beginning after rotating the transfer platen, wherein the first transfer time period includes the extension time period, and the extension time period is adjusted to facilitate equalizing the first transfer time period and the second transfer time period.

In some examples, a transfer vacuum source in selective fluid communication with the first transfer face and the second transfer face is activated according to a predetermined sequence, so that prior to transferring the first fiber mat and the second fiber mat to the dry press, the first transfer die pulls vacuum through the first fiber mat for a first total vacuum duration, and the second transfer die pulls vacuum through the second fiber mat for a second total vacuum duration, wherein the first vacuum duration and second vacuum duration are equal.

In some examples, the method further includes locking the forming platen in the pressing position before and during each pressing operation and unlocking the forming platen after each pressing operation.

In some examples, the method includes rotating the transfer platen about the second horizontal axis to direct the first and second transfer tools in opposite laterally outward directions.

In some examples, the method includes transferring the first fiber mat from the first transfer die to a first transfer robot and transferring the second fiber mat from the second transfer die to a second transfer robot.

In some examples, the method further includes simultaneously transferring the first fiber mat and the second fiber mat from the first and second transfer robots, respectively, to the first and second press stations of the dry press.

In some examples, one first fiber mat and one second fiber mat are transferred to the dry press for each cycle of the dry press.

In some examples, the method comprises engaging the transfer platen and displacing the transfer platen upwards when moving the forming platen to the pressing position.

Other aspects and features of the teachings disclosed herein will become apparent to those ordinarily skilled in the art, upon review of the following description of the specific examples of the present disclosure.

DRAWINGS

For a better understanding of the described examples and to show more clearly how they may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which:

FIG. 1 is a schematic elevation view of an example wet press of a system for producing molding fiber articles, shown in a first position;

FIG. 2 is an elevation view of the wet press of FIG. 1 shown in a second position;

FIG. 3 is an elevation view of the wet press of FIG. 1 shown in a third position;

FIG. 4 is an elevation view of the wet press of FIG. 1 shown in a fourth position;

FIG. 5 is an elevation view of the wet press of FIG. 1 shown in a fifth position;

FIG. 6 is an elevation view of the wet press of FIG. 1 shown in a sixth position;

FIG. 7 is an elevation view of the wet press of FIG. 1 shown in a seventh position;

FIG. 8 is an elevation view of the wet press of FIG. 1 shown in an eighth position;

FIG. 9 is an elevation view of the wet press of FIG. 1 shown in a ninth position;

FIG. 10 is an elevation view of the wet press of FIG. 1 shown in a tenth position;

FIG. 11 is a perspective view of another embodiment of a wet press apparatus similar to the schematic wet press of FIG. 1;

FIG. 12 is a perspective view of the forming platen and related carriage components of the wet press of FIG. 11;

FIG. 13 is a perspective view of the transfer platen of the wet press of FIG. 11;

FIG. 14 is an enlarged perspective view of an upper portion of the wet press of FIG. 11, with some components removed for improved visibility of the coupling between the transfer platen and the vertical slide structure;

FIG. 15 is an enlarged perspective view of a lower portion of the press of FIG. 11, with some components removed for improved visibility of the coupling between the forming platen and the vertical slide structure;

FIG. 16 is a further enlarged perspective view of a portion of the structure of FIG. 15, with additional components removed for improved visibility of a brake assembly portion thereof;

FIG. 17 is a flow chart depicting a method of supplying wet pressed molded fiber articles to a dry press, according to an embodiment;

FIG. 18 is a perspective view of the wet press of FIG. 11, shown in a first position;

FIG. 19 is a perspective view of the wet press of FIG. 11, shown in a second position;

FIG. 20 is a perspective view of the wet press of FIG. 11, shown in a third position;

FIG. 21 is a perspective view of the wet press of FIG. 11, shown in a fourth position;

FIG. 22 is a perspective view of the wet press of FIG. 11, shown in a fifth position;

FIG. 23 is a perspective view of the wet press of FIG. 11, shown in a sixth position;

FIG. 24 is a perspective view of the wet press of FIG. 11, shown in a seventh position;

FIG. 25 is a perspective view of the wet press of FIG. 11, shown in an eighth position;

FIG. 26 is a perspective view of the wet press of FIG. 11, shown in a ninth position;

FIG. 27 is a perspective view of an example wet press, dry press and transfer robot for receiving wet pressed fiber articles from the wet press in a fiber molding system;

FIG. 28 is a perspective view of the dry press of FIG. 27, with the robot shown in another position; and

FIG. 29 is a plan view of the dry press of FIG. 28, with the robot shown in the same position.

The drawings included herewith are for illustrating various examples of apparatuses and methods of the teaching of the present specification and are not intended to limit the scope of what is taught in any way.

DESCRIPTION OF VARIOUS EXAMPLES

Various apparatuses or processes will be described below to provide an example of each claimed invention. No example described below limits any claimed invention and any claimed invention may cover processes or apparatuses that differ from those described below. The claimed inventions are not limited to apparatuses or processes having all of the features of any one apparatus or process described below or to features common to multiple or all of the apparatuses described below. It is possible that an apparatus or process described below is not an example of any claimed invention. Any invention disclosed in an apparatus or process described below that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors, or owners do not intend to abandon, disclaim, or dedicate to the public any such invention by its disclosure in this document.

The systems and methods described herein are directed to the production of molded fiber articles (e.g. containers, cutlery, or subcomponents used in assembly of other articles or devices), and to supplying wet pressed fiber articles to a dry press in a production system producing molded fiber articles. In some examples, pulp fiber is provided in a slurry form, in a slurry tank for use in downstream processing. In some examples, a forming platen and a transfer platen are provided above the slurry tank, each of which is coupled to a frame, and configured to translate and rotate relative to the frame. In some examples, the forming platen carries a forming die, and the transfer platen carries two or more transfer dies. In some examples, each die has an article-engaging face in selective fluid communication with a vacuum or pressurized air source, and the selective fluid communication is individually controllable for each face. Each die face is shaped according to the geometry of an article that is desired to be manufactured.

In operation of some examples disclosed herein, the forming face presented by the forming platen is dipped into the slurry tank while vacuum is fluidly connected to the forming face, coating the forming face with a fiber mat comprising pulp fiber. In some examples, the forming platen is rotated and translated upwards where it contacts the transfer platen and urges it upwards. In some examples, the forming platen is locked in position and the transfer platen is pressed downwards, forming the fiber mat between the platens and urging moisture out of the mat. The platens are separated, and the transfer platen is rotated to place the fiber mat on the top side of the transfer platen while pointing a second face of the transfer platen downwards towards the forming platen. In some examples, the dipping and pressing sequence is repeated to form and press a second fiber mat on the second face of the transfer platen, such that the two fiber mats may be simultaneously provided to a dry press for further processing.

The system and methods disclosed herein facilitate optimizing the supply of wet pressed fiber mats to dry presses in the manufacturing of molded fiber articles. In some processes, the dry pressing step may be the slowest process step, limiting the throughput of the overall production process. In some cases, for example, the dry press operation may take more than twice as long as the wet press operation. For some molded fiber articles, the dry press may remain in a mold-closed position for between 20 and 30 seconds, and the cycle time of the wet press may be less than half that time. By forming two or more wet pressed fiber mats via the wet press station per cycle of the dry press, and feeding the multiple fiber mats to the dry press for each cycle of the dry press, the overall rate of part production through the system can be increased.

Referring to FIG. 1, an example wet press 100 of a system for forming molded fiber articles is configured to produce a wet-pressed pulp fiber mat, having a shape or geometry generally corresponding to one or more articles to be manufactured by the system. The wet press 100 includes, in the example illustrated, a slurry tank 102 (referred to as an open vessel in some examples) for holding a pulp slurry. Pulp slurry or fiber pulp slurry as used herein refers to a liquid in which fibers are suspended. In a non-limiting example, the liquid comprises water and the fibers comprise cellulosic material. The cellulosic material can include, for example, fibers derived from paper materials, recycled newsprint, cardboard, or virgin pulp.

In the example illustrated, the slurry tank 102 is a rectangular tank, having an open top. In other examples, the slurry tank 102 may comprise other shapes. The slurry tank 102 may be equipped with features to continuously mix or homogenize the pulp slurry in the tank, such as rotary stirrers or mixers.

The wet press 100 further comprises a forming platen 104. The forming platen 104 includes a forming tool mounting surface for holding a forming die 110 (forming mold part). In the example illustrated the forming tool mounting surface is generally planar, and located on one side of the forming platen 104. The forming die 110 has a forming face shaped according to the geometry of the fiber articles to be produced. In the example illustrated, the forming face comprises a porous forming surface 134 shaped to produce a fiber mat of the desired geometry. In the example illustrated, the porous forming surface 134 comprises a fine mesh screen, of stainless steel material.

The forming platen 104 is movable between a dipping position (FIG. 2, FIG. 7) proximate the tank 102 and a pressing position (FIG. 4, FIG. 9) spaced apart from the dipping position. In the example illustrated, the wet press 100 incudes a frame 112 (wet press support frame) that defines a vertical slide structure extending along a vertical press axis 122, and the forming platen 104 is coupled to the vertical slide structure for vertical movement of the forming platen 104 relative to the frame 112. Furthermore, in the example illustrated, the forming platen 104 is rotatably coupled to the frame, for rotation of the forming platen relative to the frame 112 about a forming platen axis 118.

More particularly, in the example illustrated, the forming platen 104 is coupled to the vertical slide structure by a first shaft that is coaxial with the forming platen axis 118. In the example illustrated, the forming platen axis 118 is oriented horizontally. A first rotatory actuator (forming platen actuator) is, in the example illustrated, coupled to the first shaft for urging rotation of, and rotational positioning of, the forming platen about the forming platen axis 118. The first rotary actuator, in the example illustrated, is a hydraulic motor, however, in other examples, the first rotary actuator may include an electric motor or pneumatic motor.

In the example illustrated, the forming platen 104 translates along the vertical slide structure when moving between the dipping position and the pressing position. Furthermore, in the example illustrated, the forming platen 104 rotates about the forming platen axis 118 when moving between the dipping position and the pressing position.

The slurry tank 102 is, in the example illustrated, positioned at a lower end of the vertical slide structure and below the forming platen 104. When in the dipping position, the forming platen 104 is proximate the slurry tank 102, and the porous forming surface 134 is directed downward for contact with (and/or immersion in) the pulp slurry in the slurry tank 102. A fiber mat may then be deposited on the forming surface 134, using, for example, a vacuum to draw material from the tank 102 towards the forming surface 134, as further described subsequently herein.

The wet press 100 further comprises a transfer platen 106 (also called a wet press platen in some examples) for holding transfer tooling 138 (or wet press mold part). The transfer platen 106 is, in the example illustrated, movable to facilitate interaction between the transfer tooling 138 held by the transfer platen 106 and the forming die 110 held by the forming platen 104.

In the example illustrated, the transfer tooling 138 includes a first transfer face 108a and a second transfer face 108b, and the transfer tooling is movable for selectively positioning each of the first transfer face 108a and the second transfer face 108b in alignment with the forming platen 104 when the forming platen is in the pressing position.

More particularly, in the example illustrated, the transfer platen 106 comprises a first transfer die mounting face 136a for supporting a first transfer die 138a of the transfer tooling 138, and a second transfer die mounting face 136b for supporting a second transfer die 138b of the transfer tooling 138. The first transfer die 138a comprises the first transfer face 108a, and the second transfer die 138b comprises the second transfer face 108b. In the example illustrated, the first and second transfer die mounting faces 136a, 136b are disposed on opposite sides of the transfer platen 106.

Each transfer face 108a, 108b is shaped according to the geometry of articles that are to be produced using the wet press 100. In the example illustrated, the first transfer face 108a and the second transfer face 108b have the same shape, for cooperating interchangeably with the geometry of the forming surface 134 of the forming die 110 to produce the desired shape of the fiber articles being produced. In the example illustrated, the first transfer die 138a comprises first apertures open to the first transfer face 108a to facilitate, for example, drawing vacuum through a fiber mat positioned against the first transfer face 108a. Similarly, in the example illustrated, the second transfer die 138b comprises second apertures open to the second transfer face 108b to facilitate, for example, drawing vacuum through a fiber mat positioned against the second transfer face 108b. In some examples, the first and second transfer faces of the first and second transfer dies 138a, 138b can comprise respective first and second mesh screens, with the first and second apertures comprising openings passing through the respective first and second mesh screens.

The transfer platen 106 is movable for selectively positioning each of the first transfer face 108a and the second transfer face 108b in alignment with the forming platen 104 when the forming platen 104 is in the pressing position. In the example illustrated, the transfer platen 106 is coupled to the vertical slide structure at a position vertically above the forming platen 104, and is vertically translatable relative to the frame 112 along the vertical slide structure. The transfer platen 106 is, in the example illustrated, positioned vertically above the forming platen 104 when the forming platen 104 is in the pressing position and in the dipping position.

Furthermore, in the example illustrated, the transfer platen 106 is rotatably coupled to the frame 112, for rotation of the transfer platen relative to the frame about a transfer platen axis 120. More particularly, in the example illustrated, the transfer platen 106 is coupled to the vertical slide structure by a second shaft that is coaxial with the transfer platen axis 120. In the example illustrated, the transfer platen axis 120 is oriented horizontally. A second rotary actuator is, in the example illustrated, coupled to the second shaft for urging rotation of, and rotational positioning of, the transfer platen 106 about the transfer platen axis 120. The second rotary actuator, in the example illustrated, is a hydraulic motor, however, in other examples, the second rotary actuator may include an electric motor or pneumatic motor.

The transfer platen 106 is, in the example illustrated, translatable along the vertical slide structure between a retracted position (e.g. FIG. 4) and an advanced position (e.g. FIG. 5). The retracted position corresponds to a raised position, spaced furthest from the tank 102 (during normal operation), and the advanced position corresponds to a lowered position, spaced below the retracted position and toward the tank 102. Furthermore, the transfer platen 106 is, in the example illustrated, rotatable about the transfer platen axis 120 between a first rotational position (e.g. FIGS. 3, 4) for positioning the first transfer die 138a in alignment with the forming surface 134, and a second rotational position (e.g. FIGS. 8, 9) for positioning the second transfer die 138b in alignment with the forming surface 134 when the forming platen 104 is in the pressing position. The transfer platen is, in the example illustrated, also rotatable about the transfer platen axis 120 to a third rotational position intermediate the first and second rotational positions.

In the example illustrated, the wet press 100 further includes a vacuum source 140 for selective fluid communication with the porous forming surface 134 of the forming die 110. For example, opening a forming vacuum control valve (FVC valve) can place the forming surface 134 in fluid communication with the vacuum source 140, and closing the FVC valve can isolate the porous forming surface 134 from the vacuum source 140. When the FVC valve is open and the forming die 110 is in the dipping position, the vacuum draws pulp slurry from the tank 102 through the porous forming surface. Solid material (pulp fiber) is deposited on the forming surface 134, while liquid is pulled through the screen and, in the example illustrated, returned to the tank 102. When the FVC valve is open and the forming die 110 is moved away from the tank 102, the vacuum through the porous screen of the forming surface 134 can help hold the fiber mat in retained engagement on the forming die 110, and can continue to draw moisture out of fiber mat (which moisture can again be returned to the tank 102). When the FVC valve is closed, the porous forming surface 134 of the forming die is isolated from the vacuum source 140 which can, for example, facilitate releasing the fiber mat from the forming die 110.

In the example illustrated, the vacuum source 140 is also in selective communication with the first apertures of the first transfer die 138a and the second apertures of the second transfer die 138b. For example, opening a first transfer vacuum control valve (first TVC valve) can place the first transfer die 138a in fluid communication with the vacuum source 140, and closing the first TVC valve can isolate the first transfer die 138a from the vacuum source 140. Similarly, opening a second transfer vacuum control valve (second TVC valve) can place the second transfer die 138b in fluid communication with the vacuum source 140, and closing the second TVC valve can isolate the second transfer die 138a from the vacuum source 140. When a respective TVC valve is open, the vacuum through the respective first and second transfer apertures of the respective first and second transfer die 138a, 138b can help hold the fiber mat in retained engagement on the transfer die 138a, 138b, and can continue to draw moisture out of fiber mat (which moisture can again be returned to the tank 102). In the example illustrated, the vacuum source 140 is separately controllable for independently providing fluid communication with the first apertures of the first transfer die 138a, the second apertures of the second transfer die 138b and/or the forming surface 134. In the example illustrated, each of the FVC valve, the first TVC valve, and the second TVC valve is an electronically controlled valve positioned in a flow path between the vacuum source 140 and the respective ones of the forming surface, the first transfer die 138a, and the second transfer die 138b, respectively.

In some examples, each transfer die 138a, 138b and the forming surface 134 are optionally in selective fluid communication with a pressurized air source 142. Respective pressure control valves, e.g. a forming pressure control valve (FPC valve), first transfer pressure control valve (first TPC valve), and second transfer pressure control valve (second TPC valve) are positioned between the pressurized air source 142 and respective ones of the forming surface 134, the first transfer die 138a, and the second transfer die 138b, respectively.

In some examples, the vacuum source 140 comprises individual vacuum sources for each component of the wet press 100 with which the vacuum source 140 is in selective fluid communication. For example, the vacuum source 140 may comprise a forming vacuum source, a first transfer vacuum source, and a second transfer vacuum source.

In the example illustrated, the forming platen 104 comprises a forming range of motion (forming stroke) 124 and the transfer platen 106 comprises a transfer range of motion (transfer stroke) 126. In the example illustrated, a portion of the forming range of motion 124 overlaps with a portion of the transfer range of motion 126 along the press axis 122.

In the example illustrated, a forming platen actuator 148 is coupled to the forming platen 104, for moving the forming platen 104 along the vertical press axis 122 In the example illustrated, the vertical slide structure comprises one or more vertical rails 144, and the forming platen 104 is coupled to the rails 144 via forming platen linear bearings 114.

In the example illustrated, a brake assembly including at least one brake 128 is coupled to the forming platen 104 for locking the forming platen 104 in the pressing position. The brake 128 is movable between an engaged position and a disengaged position. When the brake 128 is in the engaged position, the brake 128 inhibits translation of the forming platen 104 along the vertical slide structure, thereby locking the forming platen 104 in position. When the brake 128 is in the disengaged position, the forming platen 104 is readily translatable along the vertical slide structure.

In the example illustrated, the brake 128 is biased to the engaged position, for example, by an internal biasing member such as a spring or pressurized fluid chamber. The brake is movable to the disengaged position when energized, for example, by activating a release element such as opening a valve or passing current through a brake coil. In this way the brake 128 can serve as a dual function brake, firstly, by locking the forming platen in the press position during operation, and secondly, by serving as a safety brake to arrest movement of the forming platen in the event of a power failure to the wet press 100.

A pressing actuator 132 is coupled to the transfer platen 106 for pressing the transfer platen 106 towards the forming platen 104 when the forming platen 104 is locked in the pressing position. In the example illustrated, the pressing actuator 132 comprises a linear actuator, and more particularly, a hydraulic cylinder. The pressing actuator 132 is, in the example illustrated, configured to apply a pressing force of up to about 4 tons (40 kN) onto the transfer platen 106. In the example illustrated, the transfer platen is coupled to the rails 144 via transfer platen linear bearings 116.

In some examples, the pressing actuator 132 can be configured to apply a high pressure, short stroke force (pressing force) with minimal working fluid (e.g. hydraulic oil) requirements. In some examples, one or more other actuators can be used to pre-position the transfer platen 106 in a “pre-press” position, for example, in a position wherein the transfer tooling is proximate (including near or bearing lightly against) the fiber mat presented by the forming die when the forming platen is locked in the pressing position. By so doing, the working fluid fed to the pressing actuator 132 is quickly converted into building up the pressing force, rather than first translating the transfer platen 106. This can provide various benefits to the process, including, for example, increasing the energy efficiency.

In the example illustrated, the forming platen actuator 148 is configured to pre-position the transfer platen 106 in the pre-press position. In particular, in the example illustrated, before moving the forming paten 104 to the pressing position, the transfer platen 106 is moved to an advanced (lowered) position that is located along the press axis at a position vertically below the axial position of the forming platen when in the pressing position. Moving the forming platen 104 toward the pressing position (e.g. via the forming platen actuator 148), in the example illustrated, includes engaging the transfer platen 106 and pushing the transfer platen 106 axially upward from the advanced position to the pre-press position. When the forming platen 104 is in the pressing position, the brake 128 is, in the example illustrated, moved to the engaged position and the forming platen 104 is locked in the pressing position. The transfer platen 106 is in the pre-press position, whereupon energizing the pressing actuator exerts a downward force on the transfer platen 106 that is converted directly into the pressing force bearing against the fiber mat presented by the forming die.

With further reference to FIGS. 1-10, various positions of the wet-press 100 during operation can be described as follows. In the example illustrated in FIG. 1, the wet press 100 is shown in a first position 100-1, with the forming die 110 and the forming surface 134 facing downward towards the open top of the slurry tank 102, and the first transfer face 108a of the transfer platen 106 facing downward toward the forming platen 104 and the slurry tank 102. In the first position 100-1, the forming platen 104 is spaced a short distance above the slurry tank 102 (e.g. in a pre-dip position), in which the forming die 110 is not contacting the contents of the slurry tank 102. In the example illustrated, when the wet press 100 is in the first position 100-1, the transfer platen 106 is in the advanced (lowered) position.

With reference to FIG. 2, the wet press 100 is in a second position 100-2 in which the forming platen is in the dipping position, wherein the forming face 134 of the forming die 110 is dipped into the slurry tank. Transitioning from the first position 100-1 to the second position 100-2 includes, in the example illustrated, translating the forming platen 104 downward along the rails 144 of the vertical slide structure.

In the example illustrated, when in the second position 100-2, the apertures of the forming surface 134 of the forming die 110 are placed in fluid communication with the vacuum source 140, such that vacuum is drawn through the porous forming surface 134 of the forming die 110, drawing pulp fiber onto the mesh screen of the forming surface 134. This produces the fiber mat (a first fiber mat) 130 on the forming surface 134. Moisture, such as water or other liquids in the slurry tank 102 and fiber mat 130, is pulled through the porous forming surface and returned to the tank 102.

Referring to FIG. 3, when the wet press 100 is in the third position 100-3, the forming platen 104 is, in the example illustrated, spaced axially away from the tank 102 and rotated 180 degrees about the forming platen axis 118. The forming face 134 and the first fiber mat 130 thereon are directed upward, facing the transfer platen 106. Transitioning from the second position 100-2 to the third position 100-3 includes, in the example illustrated, translating the forming platen 104 vertically upward via the forming platen actuator and rotating the forming platen 104 via the first rotary actuator. In the example illustrated, the forming surface 134 remains in fluid communication with the vacuum source 140 when transitioning between the second and third positions, to facilitate holding the fiber mat 130 in retained engagement on the forming die during rotation, and to continue removing moisture from the first fiber mat 130. Furthermore, the transfer platen 106 is still in the (axially) advanced position and the first rotational position when the example wet press 100 is in the third position 100-3.

With reference to FIG. 4, when the wet press 100 is in the fourth position 100-4 in the example illustrated, the forming platen 104 is in the pressing position, with the first fiber mat 130 on the forming surface 134 in engagement with the first transfer die 138a of the transfer platen 104, and corresponding movement of the transfer platen 106 from the advanced position to the pre-press position. The brakes 128 are, in the example illustrated of position 100-4, engaged to lock the forming platen 104 in the pressing position. Once locked in position, the pressing actuator 132 is energized to apply the pressing force to the first fiber mat 130, urging the first fiber mat 130 into the desired shape and squeezing moisture out of the first fiber mat.

During transition from the third position 100-3 to the fourth position 100-4, in the example illustrated, the vacuum source 140 may remain in fluid communication with the forming surface 134. In other examples, the vacuum source 140 may be fluidly isolated from the forming surface 134 once the forming platen 104 is rotated 180 degrees from the dipping position, as gravity will hold the first fiber mat 130 on the forming die 110 in such a position. Furthermore, when in the fourth position 100-4, in the example illustrated, the first apertures of the first transfer die 138a may be in fluid communication with the vacuum source 140, to facilitate removal of moisture from the first fiber mat and returning the moisture to the tank 102.

With reference to FIG. 5, once sufficient time has elapsed for removal of a desired amount of moisture and to achieve a desired geometry of the first fiber mat, the first fiber mat is transferred from retained engagement on the forming platen 104 to retained engagement on the first transfer die 138a. This transfer is facilitated by isolating the porous forming surface 134 from the vacuum source 140 (e.g. by closing the FVC valve), while maintaining fluid communication between the first transfer face 108a and the vacuum source 140. Furthermore, the forming platen 104 is unlocked relative to the frame (e.g. by moving the brake 128 to the disengaged position), and the forming platen 104 is moved away from the transfer platen 106 (achieving a fifth position 100-5 of the wet press). In some examples, transfer of the first fiber mat from the forming platen 104 to the first transfer die 138a can include placing the forming surface 134 of the forming die 110 in fluid communication with the pressurized air source 142, as the forming platen 104 and transfer platen 106 separate from each other. In the example illustrated, lowering the forming 104 away from the pressing position causes the transfer platen to move (drop) to the advanced position.

Referring now to FIG. 6, when the wet press 100 is in a sixth position 100-6, in the example illustrated, the forming platen 104 is in the pre-dip position, and the transfer platen 106 is in the advanced position, but with the first transfer face 108a (and first fiber mat 130 thereon) facing upward. Transitioning from the fifth position 100-5 to the sixth position 100-6, includes, in the example illustrated, rotating the forming platen 180 degrees about the forming platen axis 118 and lowering the forming platen 104 to a position near the open upper end of the tank 102. Furthermore, in the example illustrated, the transfer platen 106 is rotated 180 degrees about the transfer platen axis 120 when transitioning the wet press 100 from the fifth position 100-5 to the sixth position 100-6.

In the example illustrated, during the rotation of the transfer platen 106, the vacuum source 140 remains in fluid communication with the first transfer face 108a, to retain the first fiber mat 130 on the first transfer face 108a during the rotation. After completion of the rotation, the vacuum source 140 may be fluidly isolated from the first transfer face 108a, as the fiber mat 130 is positioned vertically above the first transfer face 108a, and accordingly, is held in position by gravity. In some examples, the fluid communication may nevertheless be maintained, for example, to provide further moisture extraction from the first fiber mat.

With reference to FIG. 7, when the wet press 100 is in a seventh position, in the example illustrated, the forming platen 104 is moved into the dipping position again, and a second fiber mat 130′ is deposited on the forming surface 134, in the same way as the first fiber mat 130 during the operation of the wet press 100 associated with the second position 100-2 described previously.

With reference to FIG. 8, in the example illustrated, when the wet press 100 is in an eighth position 100-8, the machine elements are positioned similarly as when in the third position 100-3. The forming platen is spaced axially away from the tank 102 and rotated 180 degrees about the forming platen axis 118. The forming face 134 and the second fiber mat 130′ thereon are directed upward, facing the transfer platen 106. Transitioning from the seventh position to the eighth position includes translating the forming platen 104 vertically upward via the forming platen actuator and rotating the forming platen via the first rotary actuator. In the example illustrated, the forming surface 134 remains in fluid communication with the vacuum source 140 when transitioning between the seventh and eighth positions, to facilitate holding the second fiber mat 130′ in retained engagement on the forming die during rotation, and to remove further moisture from the second fiber mat 130′ .

In other examples, the vacuum source 140 may be fluidly isolated from the forming surface 134 once the forming platen 104 is rotated 180 degrees from the dipping position of the seventh position 100-7, as gravity will hold the second fiber mat 130′ on the forming die 110 in such a position.

With reference to FIG. 9, when the wet press 100 is in a ninth position 100-9, in the example illustrated, the forming platen 104 is locked in the pressing position (as in FIG. 4), and the transfer platen 106 has been translated axially upward to the pre-press position (also as described previously with regard to the fourth position 100-4 and FIG. 4).

The brakes 128 are, in the example illustrated of the ninth position 100-9, moved to the engaged position to lock the forming platen 104 in the pressing position. Once the forming platen 104 is locked in position, the pressing actuator is energized to apply the pressing force to the second fiber mat 130′, urging the second fiber mat 130′ into the desired shape and squeezing moisture out of the second fiber mat 130′.

With reference to FIG. 10, in the example illustrated, once sufficient time has elapsed for removal of a desired amount of moisture and to achieve a desired geometry of the second fiber mat 130′, the second fiber mat is transferred from retained engagement on the forming platen 104 to retained engagement on the second transfer die 138b. This transfer is facilitated by isolating the porous forming surface 134 from the vacuum source 140 (e.g. by closing the FVC valve), while maintaining fluid communication between the second transfer face 108b and the vacuum source 140. Furthermore, the forming platen 104 is unlocked relative to the frame (e.g. by moving the brake 128 to the disengaged position), and the forming platen 104 is moved away from the transfer platen 106 (achieving a tenth position 100-10 of the wet press). In some examples, transfer of the second fiber mat 130′ from the forming platen 104 to the second transfer die 138b can include placing the forming surface 134 of the forming die 110 in fluid communication with the pressurized air source 142 as the forming platen 104 and transfer platen 106 separate from each other. In the example illustrated, lowering the forming 104 away from the pressing position causes the transfer platen 106 to move (drop) to the advanced position.

In the example illustrated, after lowering the forming platen 104 away from the transfer platen 106 and moving the second fiber mat 130′ from retained engagement with the forming platen 104 to retained engagement with the transfer platen 106, the wet press 100 has completed a full cycle operation, producing a first fiber mat 130 and a second fiber mat 130′, for supply to a dry press for further processing.

In the example illustrated, during the process of forming both the first fiber mat 130 and the second fiber mat 130′, vacuum is drawn through each respective fiber mat 130, 130′ for certain total periods of time through the forming surface 134, first transfer face 108a and second transfer face 108b.

The period of time in which the first fiber mat 130 is in contact with the forming surface 134 while the vacuum source 140 is in fluid communication with the forming surface 134 is referred to as the first forming time period. The period of time in which the second fiber mat 130′ is in contact with the forming surface 134 while the vacuum source 140 is in fluid communication with the forming surface 134 is referred to as the second forming time period. During the first forming time period, the vacuum source 140 in fluid communication with the forming surface 134 retains the first fiber mat 130 on the forming surface 134 and removes moisture from the first fiber mat 130. During the second forming time period, the vacuum source 140 in fluid communication with the forming surface 134 retains the second fiber mat 130′ on the forming surface 134 and removes moisture from the second fiber mat 130′. In some examples, the first forming time period is equal to the second forming time period. This can help to provide the first fiber mat 130 and the second fiber mat 130′ with similar moisture contents when presenting the fiber mats 130, 130; to the transfer platen, which can in turn facilitate accurate processing and uniformity of product during and after subsequent operations.

The period of time in which the first fiber mat 130 is in contact with the first transfer face 108a while the vacuum source 140 is in fluid communication with the first transfer face 108a is referred to as the first transfer time period. The period of time in which the second fiber mat 130′ is in contact with the second transfer face 108b while the vacuum source 140 is in fluid communication with the second transfer face 108b is referred to as the second transfer time period. During the first transfer time period and the second transfer time period, each respective fiber mat 130, 130′ is retained on its respective transfer face, and moisture is removed from each fiber mat 130, 130′. In some examples, the first transfer time period is equal to the second transfer time period. This advantageously results in two fiber mats 130, 130′ with similar final moisture content, as moisture is drawn out of each fiber mat 130, 130′ continuously as vacuum is applied.

In some examples, the sum of the first forming time period and first transfer time period is equal to the sum of the second forming time period and second transfer time period. This advantageously results in two fiber mats 130, 130′ with similar final moisture content, as moisture is drawn out of each fiber mat 130, 130′ as vacuum is applied.

In some examples, the first transfer die 138a is maintained in fluid communication with the vacuum source 140 for an extension time period beginning after the transfer platen 106 has been rotated 180 degrees (such that the first fiber mat 130 is oriented upward) and ending before transferring the first fiber mat 130 is transferred to the dry press. In such examples, the first transfer time period includes the extension time period, and the extension time period is adjusted to facilitate equalizing the first transfer time period and the second transfer time period.

In some examples, the vacuum source 140 in selective fluid communication with the first transfer face 108a, the second transfer face 108b and the forming surface 134 is in fluid communication with each respective face 108a, 108b and surface 134 according to a predetermined sequence, such that prior to transferring the first fiber mat 130 and the second fiber mat 130′ to the dry press, the first transfer die 138a and the forming surface 134 pulls vacuum through the first fiber mat 130 for a first total vacuum duration, and the forming surface 134 and the second transfer die 138b pulls vacuum through the second fiber mat 130′ for a second total vacuum duration, wherein the first vacuum duration and second vacuum duration are equal.

In some examples, the first fiber mat 130 and second fiber mat 130′ may be removed from the wet press 100 using transfer automation (also called part handling equipment). In the example illustrated, the transfer automation includes a first transfer robot and a second transfer robot in proximity to the wet press 100. The transfer robots are each provided with respective end-of-arm tooling (or EAOT) configured to engage the first and second fiber mats 130, 130′, respectively, in releasable retained engagement. In some examples, each EOAT may be in selective fluid communication with the vacuum source 140 and/or the pressurized air source 142, to facilitate engagement and/or release of each EOAT with a respective fiber mat 130, 130′.

In some examples, the transfer robots are configured to load the first and second fiber mats 130, 130′ into respective first and second press stations of a dry press. In some examples, one first fiber mat 130 and one second fiber mat 130′ are transferred to the dry press for each cycle of the dry press.

For transfer of the first and second fiber mats 130, 130′ to the dry press in the example illustrated, the transfer platen 106 is rotated in a manner to facilitate access to both fiber mats 130, 130′ simultaneously by the transfer automation (e.g. one or more transfer robots). For example, the transfer platen 106 is rotated ninety degrees to a third rotational position intermediate the first and second rotational positions, such that the transfer die mounting surfaces are oriented generally vertically, and each fiber mat 130, 130′ faces laterally outwards of the respective transfer die 138a, 138b. This position facilitates removal of both fiber mats 130, 130′ simultaneously by the transfer robots, while simplifying the design and motion requirements of the transfer robots. In such examples, the vacuum source 140 may be placed in fluid communication with both the first transfer face 108a and the second transfer face 108b to retain each fiber mat 130, 130′ on each respective transfer face 108a, 108b. The time each fiber mat 130, 130′ is retained with vacuum on each respective transfer face 108a, 108b may be included in the first transfer time and second transfer time respectively.

In some examples of the wet press 100, actuators, brakes and valves of the wet press 100 may be electrically coupled to a control system, such that components of the wet press 100 may be activated, deactivated and adjusted according to a predetermined timed sequence.

Referring now to FIG. 11, another example of a wet press 1100 generally corresponds to the schematically illustrated wet press 100, with like features identified by like reference characters, incremented by 1000. The wet press 1100 includes a slurry tank 1102 for holding a pulp slurry. The wet press 1100 further includes a forming platen 1104 and a transfer platen 1106, each coupled to a vertical slide structure of a frame 1112, the vertical slide structure extending along a vertical press axis 1122.

With reference also to FIGS. 12 and 15, in the example illustrated, the forming platen 1104 is coupled to the vertical slide structure by a first shaft 1150 extending between opposed first carriage plates 1152 of a forming platen carriage 1154 that is slidably coupled to the vertical slide structure (and in particular, to linear rails 1144 of the vertical slide structure) by a set of first linear bearings 1114. The first shaft 1150 is coaxial with a horizontally oriented forming platen axis 1118 (FIG. 11) about which the forming platen 1104 is rotatable. A first rotatory actuator 1171 is, in the example illustrated, coupled to the first shaft 1150 for urging rotation of the forming platen 1104 about the forming platen axis 1118.

The forming platen 1104 comprises a die mounting surface for holding a forming die 1110 (FIG. 12). The forming die 1110 comprises a forming surface 1134, having a geometry corresponding to the fiber mat (e.g. fiber mat 130, 130′) that is to be produced by the wet press 1100. The fiber mat has a shape that generally corresponds to the shape of the molded fiber articles to be produced by the system. A single fiber mat may have a size and shape that corresponds to multiple fiber articles being produced by the system. In the example illustrated, each fiber mat includes a plurality of discrete fiber mat segments, and more particularly, includes sixteen fiber mat segments for producing sixteen distinct fiber articles.

In the example illustrated, the forming surface 1134 is a porous forming surface, comprising a fine mesh screen of stainless steel material. The forming surface 1134 is in selective fluid communication with a vacuum source and a pressurized air source. A forming vacuum control valve (FVC valve) is positioned between the forming surface 1134 and the vacuum source. A forming pressure control valve (FPC valve) is positioned between the forming surface 1134 and the pressurized air source. The FPC valve is opened to place the forming surface 1134 in fluid communication with the pressurized air source. The FVC valve is opened to place the forming surface 1134 in fluid communication with the vacuum source. The forming surface 1134 can be placed in fluid communication with the pressurized air source or vacuum source as desired, with specific timing, by timing the opening of each valve.

Referring to FIG. 13, the transfer platen 1106 is configured to hold multiple transfer dies, each transfer die for cooperating with the forming die to wet press a respective fiber mat presented by the forming die 1110. In the example illustrated, the transfer platen is configured to hold two forming dies 1110, and has two transfer die mounting surfaces 1136. More particularly, in the example illustrated, the transfer platen 1106 includes a first transfer die mounting face 1136a for mounting a first transfer die 1138a thereto. Further, the transfer platen 1106 comprises a second transfer die mounting face 1136b, for mounting a second transfer die 1138b thereto.

Each transfer die 1138a, 1138b comprises a transfer face 1108a, 1108b respectively. Each transfer face 1108a, 1108b is shaped according to the geometry of the fiber mats that are to be produced by the wet press 1100. The geometry of the fiber mats corresponds to the geometry of a molded fiber article being manufactured. In the example illustrated, the geometry of each transfer face 1108a, 1108b is identical, and each cooperates with the forming face 1134 to produce first and second fiber mats 130, 130′, respectively, that are identical.

Each of the first transfer die 1138a and second transfer die 1138b comprise first and second apertures respectively. The first and second apertures of each of the first transfer die 1138a and second transfer die 1138, respectively, are in selective fluid communication with a vacuum source and a pressurized air source. The first and/or second apertures of each transfer die 1138a, 1138b can be placed in fluid communication with the vacuum source by opening a first transfer vacuum control valve (first TVC valve), and/or second transfer vacuum control valve (second TVC valve). The first and/or second apertures of each transfer die 1138a, 1138b can be placed in fluid communication with the pressurized air source by opening a first transfer pressure control valve (first TPC valve), and/or second transfer pressure control valve (second TPC valve). Each of the apertures of each transfer die 1138a, 1138b can be placed in fluid communication with the pressurized air source or vacuum source as desired, with specific timing, by timing the opening of each valve.

With reference also to FIG. 14, the transfer platen 1106 is, in the example illustrated, coupled to the vertical slide structure by a second shaft 1156 extending between opposed second carriage plates 1158 of a transfer platen carriage 1160 that is slidably coupled to the vertical slide structure by a set of second linear bearings 1116. The second shaft 1156 is coaxial with a horizontally oriented transfer platen axis 1120 (FIG. 11) about which the transfer platen 1106 is rotatable. A second rotatory actuator is, in the example illustrated, coupled to the second shaft 1156 for urging rotation of the transfer platen 1106 about the transfer platen axis 1120. Each of the first and second rotary actuators includes, in the example illustrated, a hydraulic motor, however, in other examples, either rotary actuator may include an electric motor or pneumatic motor.

In the example illustrated, the vertical slide structure comprises rails 1144 (FIG. 14). Two transfer platen linear bearings 1116 (upper and lower) for engaging the rails 1144 are provided along each side of each of the opposed second carriage plates 1158 of the transfer carriage 1160, so that, in the example illustrated, the transfer platen 1106 is coupled to the vertical slide structure by eight linear bearings 1116. The vertical slide structure further includes, in the example illustrated, stops 1146 provided along and fixed relative to each rail 1144, the stops 1146 configured to limit the transfer range of motion of the transfer platen 1106 along the rails 1144. For example, the transfer platen 1106 can translate downward (e.g. by an actuator or by gravity) along the rails 1144 no further than the stops 1146. In the example illustrated, the stops 1146 are configured such that the full weight of the transfer platen 1106 can be supported by the stops 1146.

The forming platen 1104 and transfer platen 1106 are, in the example illustrated, positioned vertically above the slurry tank 1102, with the transfer platen 1106 positioned above the forming platen 1104. The forming platen 104 is movable between a dipping position (FIG. 18) proximate the tank 1102 and a pressing position (FIG. 24) spaced apart from the dipping position. In the example illustrated, a forming platen actuator 1148 is coupled to the forming platen 1104, for moving the forming platen 1104 between the dipping position and the pressing position, and in the example illustrated, for moving the forming paten 104 along the vertical slide structure.

With reference also to FIG. 16, in the example illustrated, a brake assembly including at least one brake 1128 is coupled to the forming platen 1104, for locking the forming platen 1104 in position relative to the vertical slide structure when the brake 1128 is energized. In the example illustrated, the brake 1128 locks the forming platen 1104 to prevent movement thereof when the transfer platen applies the pressing force against the forming platen 1106 during a pressing operation. The brake 1128 also, in the example illustrated, locks the forming platen in position in situations where unintended movement of the forming platen may otherwise occur, such as during power interruption to the wet press 1100. In this way the brake 1128 can function as a safety brake in an emergency setting as well as a locking brake during normal operation.

In the example illustrated, at least one pressing actuator 1132 is coupled to the transfer platen 1106, for pressing the transfer platen 1106 towards the forming platen 1104 when the forming platen 1104 is locked in the pressing position. Two pressing actuators 1132 are present in the example wet press 1100, each capable of providing up to about 2 tons (20 kN) of pressing force, for a total pressing force of about 4 tons (40 kN). Each pressing actuator 1132 is, in the example illustrated, a hydraulic cylinder. In other examples, different forms of pressing actuators 1132 may be present, with differing force specifications.

Referring to FIG. 17, a method 2000 of feeding a dry press with fiber mats includes operations 2002, 2004, 2006, 2008, 2010, 2012, 2014, 2016, 2018, 2020 and 2022. While operations of the method 2000 are presented in sequential order in the example illustrated, in other examples, the method 2000 may be conducted in different orders. Method 2000 may correspond to a method of operation of wet presses 100 and 1100 which are described herein.

In the example method 2000, at operation 2002, a forming platen is moved to dip a forming face of a forming die secured thereto into a slurry tank and deposit a first fiber mat on a porous forming surface of the forming face.

At operation 2004, the forming platen is moved to a pressing position, wherein the forming platen is rotated about a first horizontal axis to direct the forming face upwards.

At operation 2006, a first transfer die of transfer tooling mounted to the transfer platen is pressed against the first fiber mat on the forming platen when the forming platen is in the pressing position, the transfer platen having a second transfer die opposite the first transfer die;

At operation 2008, the forming platen is moved proximate the slurry tank, wherein the forming platen is rotated about the first horizontal axis to direct the forming face downwards.

At operation 2010, the transfer platen is rotated about a second horizontal axis to direct the first transfer die upwards and the second transfer die downwards.

At operation 2012, the forming face is dipped in the slurry tank, to deposit a second fiber mat on the porous forming surface of the forming face.

At operation 2014, the forming platen is moved to the pressing position, wherein the forming platen is rotated about the first horizontal axis to direct the forming face upwards.

At operation 2016, the second transfer die of the transfer tooling mounted to the transfer platen is pressed against the second fiber mat on the forming platen when the forming platen is in the pressing position.

At operation 2018, the second fiber mat is transferred from retained engagement on the forming face to retained engagement on the second transfer die.

At operation 2020, the first fiber mat and the second fiber mat are transferred from the transfer tooling to first and second mold portions of the dry press.

With further reference to FIGS. 18 to 26, various positions of the wet-press 1100 during operation can be described as follows.

In the example illustrated in FIG. 18, the wet press 1100 is shown in a first position 1000-1. In the first position 1100-1, the forming die 1110 is facing downwards towards the slurry tank 1102, and the forming platen 1104 is positioned along the vertical press axis 1122 such that the forming surface 1134 is within the slurry tank 1102 (i.e. the forming platen 1104 is in the dipping position). The forming die 1110 may be coated with a fiber pulp by drawing the contents of the slurry tank 1102 through the forming surface 1134 via vacuum. In the first position 1100-1 of the wet press 1100, in the example illustrated, the transfer platen 1106 is in a rotational position (i.e. a third rotational position) wherein the transfer faces 1108a, 1108b are facing laterally outwards. The transfer platen 1106 is spaced apart from the forming platen 1104 along the vertical slide structure. In the first position 1100-1, the forming platen 1104 is in the dipping position.

With reference to FIG. 19, the wet press 1100 is in an example second position 1100-2, wherein the forming die 1110 is outside of the slurry tank 1102. Transitioning from the first position 1100-1 to the second position 1100-2 includes, in the example illustrated, translating the forming platen 1104 upwards along the rails 1144 of the vertical slide structure, such that the forming die 1110 is above the surface of the contents of the slurry tank 1102.

With reference to FIG. 20, the wet press 1100 is in a third position 1100-3, wherein the forming die 1100 is facing laterally outwards. Transitioning from the second position 1100-2 to the third position 1100-3 includes, in the example illustrated, rotating the forming platen 1104 ninety degrees about the forming platen axis 1118, such that the forming die 1110 is facing laterally outwards.

With reference to FIG. 21, the wet press 1100 is in an example fourth position 1100-4, wherein the forming die 1110 is facing upwards, toward the transfer platen 1106. Transitioning from the third position 1100-3 to the fourth position 1100-4 includes, in the example illustrated, rotating the forming platen 1104 a further ninety degrees about the forming platen axis 1118, such that the forming die 1110 is facing upwards, away from the tank 102 and toward the transfer platen 1106.

With reference to FIG. 22, the wet press 1100 is in an example fifth position 1100-5, with one transfer face (e.g. first transfer face 1108a) of the transfer platen 1106 facing downwards toward the forming platen 1104. Transitioning from the fourth position 1100-4 to the fifth position 1100-5 includes, in the example illustrated, rotating the transfer platen 1106 ninety degrees about the transfer platen axis 1120, such that the first transfer face 1108a is facing downwards, toward the forming platen 1104.

With reference to FIG. 23, the wet press 1100 is in an example sixth position 1100-6, wherein the forming platen 1104 is locked in the pressing position. Transitioning from the fifth position 1100-5 to the sixth position 1100-6 includes, in the example illustrated, translating the forming platen 1104 upwards along the vertical slide structure, such that the fiber mat (e.g. first fiber mat 130) carried by the forming platen 1104 is moved proximate the transfer face of downwardly-directed transfer die fixed to the transfer platen 1106. In the example illustrated, when the wet press 1100 is in the sixth position 1100-6, the fiber mat carried by the forming platen 1104 is spaced slightly apart from the proximate transfer face of the transfer die by a narrow vertical gap.

With reference to FIG. 24, when the wet press 1100 is in a seventh position 1100-7, in the example illustrated, the forming platen 1104 is locked in the pressing position and the transfer platen 1106 is urged downwards against the forming platen 1104. Transitioning from the sixth position 1100-6 to the seventh position 1100-7 includes, in the example illustrated, translating the transfer platen 1106 downward a short distance to close the vertical gap, whereupon the proximate transfer face contacts the fiber mat carried by the forming platen 1104. Also when in the seventh position 1100-7, the brake 1128 is in the engaged position, locking the forming platen 1104 to the frame. Activating the pressing actuators 1132 applies the pressing force to the fiber mat (e.g. first fiber mat 130) disposed between the forming platen 1104 and the transfer platen 1106.

With reference to FIG. 25, the wet press 1100 is in an eighth position 1100-8, in which the forming platen 1104 is lowered away from the transfer platen 1106. Transitioning from the seventh position 1100-7 to the eighth position 1100-8 includes, in the example illustrated, energizing the brake 1128 to move the brake 1128 to the disengaged position. The transition further includes translating the forming platen 1104 downwards along the vertical slide structure.

With reference to FIG. 26, the wet press 1100 is in a ninth position 1100-9, wherein the forming die 1110 is proximate to, but outside of, the slurry tank 1102, and the transfer platen 1106 is rotationally oriented (e.g. to the third rotational position) such that each transfer face 1108a, 1108b is facing laterally outward. Transitioning from the eighth position 1100-8 to the ninth position 1100-9 includes, in the example illustrated, rotating the transfer platen 1106 ninety degrees about the transfer platen axis 1120 such that both transfer faces 1108a, 1108b are facing laterally outward. Additionally, the transition includes rotating the forming platen 1104 by 180 degrees such that the forming die 1110 is facing downward toward the open top of the slurry tank 1102.

Referring now to FIGS. 27 and 28, an example dry press 2000 has multiple dry press stations (in some examples, referred to as dry presses), wherein each dry press station is configured to receive a respective fiber mat from the wet press 100, 1100. During operation, the dry press 2000 closes to simultaneously press and dry the multiple fiber mats (one fiber mat per press station). In the example illustrated, the number of dry press stations advantageously corresponds to the number of transfer faces carried by the transfer platen of the wet press 100, 1100.

More particularly, in the example illustrated, the dry press 2000 includes a first press station 2002 and a second press station 2004. In the example illustrated, the dry press 2000 is configured as a horizontal stack press, including a base 2006 supporting a stationary platen 2012 at one end of the base 2006, a moving platen 2014 spaced apart from the stationary platen 2012, and a center platen 2016 disposed between the stationary and moving platens 2012, 2014. A press actuator is coupled to the moving platen 2014 for translating the moving platen 2014 horizontally toward and away from the stationary platen 2012. The center platen 2016 is coupled to the moving platen 2014 with a pivoting linkage assembly so that the center platen 2016 translates with, but at a predetermined fraction of, the translation of the moving platen 2014.

Opposing faces of the stationary platen 2012 and the center platen 2016 are provided with first and second mold portions 2002a, 2002b, respectively, which together define the first press station 2002. Opposing faces of the moving platen 2014 and the center platen 2016 are provided with third and fourth mold portions 2004a, 2004b, respectively, which together define the second press station 2004.

A transfer automation system 2020 (in some examples, referred to as a wet-to-dry transfer subsystem) is provided for transferring the fiber mats from a wet press (e.g. the wet press 100 or the wet press 1100) to the dry press 2000. In the example illustrated, the transfer automation 2020 includes a first transfer robot 2022a for loading fiber mats (e.g. first fiber mats 130) into the first press station 2002, and a second transfer robot 2022b for loading fiber mats (e.g. second fiber mats 130′) into the second press station 2004.

In the example illustrated, the first transfer robot 2022a comprises first end-of-arm tooling (first EOAT) 2024a, configured to engage a first fiber mat 130. The second transfer robot 2022b includes, in the example illustrated, a second EOAT 2024b configured to engage a second fiber mat 130′. The EOAT may be referred to as wet-to-dry carrier members in some examples.

In the example illustrated, the first and second robots simultaneously receive first and second fiber mats from the wet press when moved to respective pick-up positions, in which the first and second EAOT are aligned with the laterally outwardly directed first and second transfer faces (e.g. 1108a, 1108b) presented by the transfer platen (e.g. 1106).

Once the first and second fiber mats 130, 130′ have been received in retained engagement on the first and second EOATs, respectively, the first and second transfer robots can be moved toward the dry press 2000, and when the dry press is open, can move to a drop-off position (see FIGS. 28 and 29) in which the first and second EOAT are aligned with and proximate to the opposed faces of the center platen (i.e. aligned with and proximate to the mold portions 2002b, 2004b of the first and second press stations) respectively. The first and second EAOT can be in selective fluid communication with the vacuum source 140 when in the pick-up position and when moving to the drop-off position to facilitate retaining the fiber mat on each EAOT. The first and second EAOT can be in selective fluid communication with the pressurized air source 142 when in the drop-off position to facilitate transferring the fiber mat to the respective first and second press stations.

Once the first and second fiber mats 130, 130′ have been loaded in the first and second press stations 2002, 2004, the transfer robots can withdraw and the dry press can be activated to close the press and exert a dry press force simultaneously on the first and second fiber mats, further forming and drying the fiber mats.

What has been described above is intended to be illustrative of examples of the teaching disclosed herein, without limiting the scope of patent claims granted herefrom. The scope of such claims should be given the broadest interpretation consistent with the description as a whole.

Claims

1. A wet press for forming molded fiber products, comprising:

a) a slurry tank for holding a pulp slurry;

b) a forming platen for holding a forming die having a porous forming surface, the forming platen movable between a dipping position proximate the tank and a pressing position spaced apart from the dipping position; and

c) a transfer platen for holding transfer tooling having a first transfer face and a second transfer face, the transfer platen movable for selectively positioning each of the first transfer face and the second transfer face in alignment with the forming platen when the forming platen is in the pressing position.

2. The wet press of claim 1, further comprising:

a) a brake coupled to the forming platen for locking the forming platen in the pressing position when the brake is in an engaged position; and

b) a pressing actuator coupled to the transfer platen for pressing the transfer platen towards the forming platen when locked in the pressing position.

3. The wet press of claim 2, wherein the brake is biased to the engaged position when unenergized, and movable to a disengaged position when energized.

4. The wet press of claim 1, wherein the transfer platen has a first transfer die mounting surface for supporting a first transfer die of the transfer tooling and a second transfer die mounting surface for supporting a second transfer die of the transfer tooling, wherein the first and second transfer die mounting surfaces are positioned on opposite sides of the transfer platen.

5. The wet press of claim 4, wherein the transfer platen is rotatable about a transfer platen axis between a first rotational position for positioning the first transfer tool in alignment with the forming surface and a second rotational position for positioning the second transfer die in alignment with the forming surface.

6. The wet press of claim 1, wherein the forming platen is rotatable about a forming platen axis when moving between the dipping position and the pressing position.

7. The wet press of claim 1, further comprising a vacuum source for selective fluid communication with the porous forming face, and for selective communication with first apertures in the first transfer die and second apertures in the second transfer die.

8. The wet press of claim 7, wherein the vacuum source is separately controllable for independently providing fluid communication with the first apertures of the first transfer die and the second apertures of the second transfer die.

9. The wet press of claim 1, wherein the transfer platen is positioned vertically above the forming platen when the forming platen is in the dipping position and in the pressing position.

10. The wet press of claim 1, wherein the forming platen and the transfer platen are each translatable along a vertical press axis.

11. A method for supplying wet pressed molded fiber articles to a dry press, the method comprising:

a) moving a forming platen to dip a forming face of a forming die secured thereto into a slurry tank and deposit a first fiber mat on a porous forming surface of the forming face;

b) moving the forming platen to a pressing position, wherein the forming platen is rotated about a first horizontal axis to direct the forming face upwards;

c) pressing a first transfer die of transfer tooling mounted to the transfer platen against the first fiber mat on the forming platen when the forming platen is in the pressing position, the transfer platen having a second transfer die opposite the first transfer die;

d) transferring the first fiber mat from retained engagement on the forming platen to retained engagement on the first transfer die;

e) rotating the transfer platen about a second horizontal axis to direct the first transfer die upwards and the second transfer die downwards;

f) moving the forming platen proximate the slurry tank, wherein the forming platen is rotated about the first horizontal axis to direct the forming face downwards;

g) dipping the forming face in the slurry tank, to deposit a second fiber mat on the porous forming surface of the forming face;

h) moving the forming platen to the pressing position, wherein the forming platen is rotated about the first horizontal axis to direct the forming face upwards;

i) pressing the second transfer die of the transfer tooling mounted to the transfer platen against the second fiber mat on the forming platen when the forming platen is in the pressing position;

j) transferring the second fiber mat from retained engagement on the forming face to retained engagement on the second transfer die; and

k) transferring the first fiber mat and the second fiber mat from the transfer tooling to first and second press stations of the dry press.

12. The method of claim 11, wherein the porous forming surface of the forming face is in fluid communication with a forming vacuum source for at least: a first forming time period during operations a) through e) to deposit and retain the first fiber mat on the forming face and remove moisture from the first fiber mat; and, a second forming time period during operations g) through i) to deposit and retain the second fiber mat on the forming face and remove moisture from the second fiber mat.

13. The method of claim 12, wherein the first forming time period is equal to the second forming time period.

14. The method of claim 11, wherein the first transfer die is in fluid communication with a first transfer vacuum source for a first transfer time period during operations c) through e) for removing moisture from the first fiber mat and retaining the first fiber mat on the first transfer die.

15. The method of claim 14, wherein the second transfer die is in fluid communication with a second transfer vacuum source for a second transfer time period during operations c) through e) for removing moisture from the second fiber mat and retaining the second fiber mat on the second transfer tooling.

16. The method of claim 15, wherein the first transfer time period is equal to the second transfer time period.

17. The method of claim 16, wherein the first transfer die is maintained in fluid communication with the first transfer vacuum source for an extension time period beginning after rotating the transfer platen in operation e) and ending prior to operation k), wherein the first transfer time period includes the extension time period, and the extension time period is adjusted to facilitate equalizing the first transfer time period and the second transfer time period.

18. The method of claim 11, wherein a transfer vacuum source in selective fluid communication with the first transfer face and the second transfer face is activated according to a predetermined sequence, so that prior to transferring the first fiber mat and the second fiber mat to the dry press, the first transfer die pulls vacuum through the first fiber mat for a first total vacuum duration, and the second transfer die pulls vacuum through the second fiber mat for a second total vacuum duration, wherein the first vacuum duration and second vacuum duration are equal.

19. The method of claim 11, further comprising locking the forming platen in the pressing position before and during each pressing operation c) and i), and unlocking the forming platen after each pressing operation c) and i).

20. The method of claim 11, wherein operation k) includes rotating the transfer platen about the second horizontal axis to direct the first and second transfer tools in opposite laterally outward directions, and wherein operation k) preferably further includes transferring the first fiber mat from the first transfer die to a first transfer robot, and transferring the second fiber mat from the second transfer die to a second transfer robot, and wherein operation k) preferably further includes simultaneously transferring the first fiber mat and the second fiber mat from the first and second transfer robots, respectively, to the first and second press stations of the dry press, and wherein preferably one first fiber mat and one second fiber mat are transferred to the dry press for each cycle of the dry press.