Pickup press device and method for producing 3D molded products from pump slurry

Abstract

The present document relates to a pick-up pressing device for use in a process for producing a 3D molded product from a pulp slurry, the pick-up pressing device comprising: a pick-up pressing tool presenting a porous first product face; a pressing tool presenting a second product surface; and a vacuum source connected to the pick-up pressing tool. The pick-up pressing tool and the pressing tools are vertically movable relative to each other wherein, in a first relative position of the pressing tools, at least one of the product faces is positioned to receive a layer of pulp slurry in liquid form to its product face, and wherein, in a second relative position of the pressing tools, at least one of the product faces is positioned to receive a layer of pulp slurry in liquid form to its product face. The product faces are pressed towards each other for pressing a layer of pulp slurry. The apparatus further comprises a first transfer tool wherein the first transfer tool comprises: a first forming surface portion configured to conform to a first portion of the porous first product face such that a forming gap is defined therebetween, the forming gap defining a desired pulp slurry layer thickness; and a second forming surface portion configured to diverge from a second portion of the porous first product face such that a non-forming space is defined by the second forming surface portion and the second portion of the porous first product face, the non-forming space having a thickness greater than the forming gap.

Description

[0001] This application is a divisional application of an application with an application date of January 3, 2020, application number 202080007884.7, and invention name “Picking and pressing device and method for producing 3D molded products from pulp slurry”. Technical Field

[0002] The present document relates to a pick-up press device for use in a process of moulding a product from a pulp slurry.The present disclosure also relates to a method of moulding a product from a pulp slurry. Background Art

[0003] It is known to mould products from a pulp slurry by dipping a porous mould into the pulp slurry and subsequently drying and optionally pressing the product so moulded. Examples of these products are egg cartons, shock absorbing packaging inserts and paper trays, paper cups, beverage takeaway trays, mushroom and berry boxes and other forms of industrial, agricultural and consumer packaging.

[0004] With regard to molding products from pulp, it is desirable to provide a mold that is durable and can withstand high temperatures. Further, smooth surface texture, reduced energy consumption and improved quality control of the molding process are desirable.

[0005] In relation to these aspects, WO 2016101976 A1 discloses an improved tool or tool part for use in moulding products from pulp, the tool or tool part comprising a self-supporting tool wall portion having a product face for contacting the product, and a back face of the wall on the other side of the product face. The tool wall portion exhibits porosity provided by a plurality of channels extending through the tool wall portion from the product face to the back face. Such a tool or tool part is also capable of providing efficient pick-up, transfer or evaporation of the pulp used, or of moulding the product, while requiring less energy to generate a vacuum than other known tools.

[0006] However, it is desirable to further reduce energy consumption.

[0007] WO 2016101976 A1 further discloses a method for moulding a product from a pulp slurry by applying a slurry layer to a porous mould and removing water from the slurry by simultaneously heating and pressing the slurry layer while drawing a vacuum through a mould wall, the other side of which is in contact with the slurry layer. The moulding process can be performed in two or more successive pressing steps, which is advantageous because it reduces the cycle time and thus increases the output of the production process compared to a process with a single pressing step.

[0008] However, further increases in production are desired. Summary of the invention

[0009] An object of the present disclosure is to provide an improved pulp moulding apparatus for moulding products from pulp slurry, and more particularly to provide an apparatus which increases the output of the moulding process compared to the prior art.

[0010] It is a further object of the present disclosure to provide an improved molding process, and more particularly to provide a method of molding a product from a pulp slurry which increases the throughput of the production process.

[0011] The invention is defined by the accompanying independent claim. Embodiments are set out in the accompanying dependent claims and in the following description and drawings.

[0012] According to a first aspect, a pick-up and pressing device for use in a process for producing 3D molded products from pulp slurry is provided, the pick-up and pressing device comprising: a pick-up and pressing tool presenting a porous first product surface, a pressing tool presenting a second product surface, and a vacuum source connected to the pick-up and pressing tool, wherein the pick-up and pressing tool and the pressing tool are vertically movable relative to each other, wherein, when in a first relative position of the pressing tools, at least one of the product surfaces is positioned to receive a pulp slurry layer in liquid form to its product surface, and wherein, when in a second relative position of the pressing tools, the product surfaces are pressed toward each other for pressing the pulp slurry layer. The device further includes a first transfer tool, wherein the first transfer tool includes: a first molding surface portion, which is configured to conform to the first portion of the porous first product surface so that a molding gap is defined between them, and the molding gap defines the desired pulp slurry layer thickness; and a second molding surface portion, which is configured to diverge from the second portion of the porous first product surface so that a non-molding space is defined by the second molding surface portion and the second portion of the porous first product surface, and the thickness of the non-molding space is greater than the molding gap.

[0013] For the purposes of this disclosure, the term "pulp" should be interpreted as comprising materials including fibers (such as cellulose), minerals and starch, or combinations of these materials. The pulp preferably has a liquid carrier, which may include water.

[0014] "Product face" refers to the surface of a tool adapted to come into contact with a pulp slurry layer or a pulp product during forming of such pulp product.

[0015] The second product face may be porous or non-porous. Alternatively, the second product face may present a porous portion and a non-porous portion.

[0016] The vacuum source may be in the form of a vacuum chamber connected to a pressure regulator.

[0017] "Pick-up" means that the pulp fibers are drawn to the porous first product side of the pick-up press tool.

[0018] When picking up the pressing tool and in the second relative position of the pressing tool, wherein the product faces are pressed towards each other for pressing the pulp slurry, at least one of the tools may be adapted to supply heat to the product face of the tool. Further, at least one of the tools having a porous product face or presenting a porous portion may be connected to a vacuum source so that a vacuum can be drawn through the porous product face of the tool.

[0019] Since the pick-up pressing tool is adapted for both picking up the pulp slurry layer and pressing the pulp slurry layer, the need for an additional transfer tool for transferring the pulp layer from the pick-up tool to the pressing tool is eliminated.

[0020] Furthermore, since the pick-up and pressing tools and the pressing tools are also movable vertically relative to each other, an efficient process for picking up and pressing the pulp slurry layer may be achieved, thereby shortening the cycle time and increasing the output of the process.

[0021] The first transfer tool may be adapted to transfer the pulp slurry layer from the pick-up press tool to the product side of the second pair of press tools.

[0022] The first transfer tool may be connected to a pressure regulator capable of generating vacuum or air pressure.

[0023] The first transfer tool can also be mounted on the transfer tool holder.

[0024] Since the non-forming space is defined by the second forming surface portion and the second portion of the porous first product face, at least a portion of the pulp slurry layer may be free during said transfer.

[0025] As the pulp slurry layer is transferred from the first transfer tool to the product side of the second pair of pressing tools, a free portion of the pulp slurry layer may be formed so as to contact the second forming surface portion of the first transfer tool.

[0026] Further, because the first transfer tool is adapted to transfer the pulp slurry layer to the second pair of cooperating pressing tools and form at least a portion of the pulp slurry layer during transfer, additional forming or pressing steps can be omitted and shorter cycle times and increased throughput of the process can be achieved.

[0027] Further, because the first transfer tool is adapted such that at least a portion of the pulp slurry layer is in contact with the first forming surface portion of the first transfer tool during transfer and at least a portion is free, i.e. not in contact, a pulp slurry layer can be provided presenting different portions with different moisture content levels.

[0028] The pick-up pressing tool may be provided with at least one heating element adapted to supply heat to the porous first product face of the pick-up pressing tool.Alternatively or additionally, the pressing tool may be provided with at least one heating element adapted to supply heat to the second product face of the pressing tool.

[0029] In the second relative position of the pressing tools, the product faces are pressed towards each other in order to press the pulp slurry layer while the pulp slurry layer is heated by the at least one heating element and a vacuum is drawn through the porous product face of at least one of the tools.

[0030] The non-forming space may be configured to provide contact between only one pulp slurry layer layer and one of the second forming surface portion and the second portion of the porous first product face.

[0031] By "pulp slurry layer face" is meant the surface of the pulp slurry layer which is adapted to come into contact with the product side of a tool, such as a pick-up pressing tool, a pressing tool or a transfer tool.

[0032] The non-forming space may present a space between the second forming surface portion and the second portion of the porous first product face which is greater than 20 times the thickness of the forming gap, preferably greater than 15 times, 10 times or 5 times the thickness of the forming gap.

[0033] The non-forming space may be provided at an innermost portion of the female mold and / or a distal end portion of the male mold as seen in the pressing direction.

[0034] Alternatively, the non-forming space may be provided at an outermost portion of the female mold and / or a distal end portion of the male mold as seen in the pressing direction.

[0035] The female mold can be a pick-up pressing tool or a pressing tool. The male mold can be a transfer tool.

[0036] The forming gap may present a thickness that is small enough so that both the first forming surface portion and the first portion of the porous first product face are in contact with the respective pulp slurry layer levels.

[0037] The forming gap may be configured to provide a pressure on the pulp slurry layer that is greater than ambient pressure.

[0038] The first shaping surface portion may present a contact surface area corresponding to 10-99.9%, preferably 25-95%, of the total area of ​​the porous first product face.

[0039] The first transfer tool may present a porous product face having a porosity of 10-90%.

[0040] For purposes of this disclosure, the term "porosity" is defined as the pore opening area of ​​a predetermined product face portion relative to the total product face area (including the pore openings).

[0041] The porous product face of the first transfer tool may present pores with a hole size of 0.1-0.7 mm in diameter, preferably 0.25-0.6 mm.

[0042] The porosity of the porous first product side of the pick-up pressing tool may be 10-90%.

[0043] The porous first product side of the pick-up pressing tool may present holes with a hole size of 0.1-0.7 mm in diameter, preferably 0.25-0.6 mm.

[0044] The pick-up press tool may be provided with at least one heating element adapted to supply heat to the porous first product face of the pick-up press tool.

[0045] The heating element may be an electric heating element, a hot air or liquid heating element or an induction heating element. The heating element may be controlled by a controller.

[0046] The pressing tool may be provided with at least one heating element adapted to supply heat to the second product side of the pressing tool.

[0047] The heating element may be an electric heating element, a hot air or liquid heating element or an induction heating element. The heating element may be controlled by a controller.

[0048] According to a second aspect of the present invention, a method for producing a 3D molded product from pulp slurry is provided, the method comprising: applying a pulp slurry layer in liquid form to a porous first product surface of a pick-up pressing tool of a first mold; in a first forming step, pressing the pulp slurry layer on the porous first product surface of the pick-up pressing tool onto a second product surface of a mating pressing tool of the first mold, while heating the pulp slurry layer and vacuuming through the porous product surface of at least one of these tools; transferring the pulp slurry layer to the porous product surface of the first pressing tool of a second mold; in a second subsequent forming step, pressing the pulp slurry layer on the second product surface of the second pressing tool of the second mold, while heating the pulp slurry layer and vacuuming through the porous product surface of at least one of the first pressing tool and the second pressing tool of the second mold, wherein at least a portion of the pulp slurry layer is formed during the transfer to the first pressing tool of the second mold.

[0049] Optionally, a washing step of the pulp slurry layer may be performed before the second forming step.

[0050] The pick-up pressing tool and the mating pressing tool of the first mould and / or the first pressing tool and the second pressing tool of the second mould may form part of a pick-up pressing device according to what has been described above.

[0051] The transfer of the pulp slurry layer from the first mold to the second mold can be performed by a first transfer tool, the first transfer tool comprising a first forming surface portion and a second forming surface portion, wherein, during the transfer of the pulp slurry layer from the first mold to the first transfer tool, the first forming surface portion conforms to the first portion of the porous first product surface of the first mold so that a forming gap is defined therebetween, the forming gap defining a desired pulp slurry layer thickness, and wherein the second forming surface portion diverges from the second portion of the porous first product surface of the first mold so that a non-forming space is defined by the second forming surface portion and the second portion of the porous first product surface of the first mold, the thickness of the non-forming space being greater than the forming gap.

[0052] The first transfer tool may be porous.

[0053] The first transfer tool can form part of a pick-up and pressing device according to what has been described above.

[0054] The forming gap may provide a pressure on the pulp slurry layer which is greater than the ambient pressure during the transfer of the pulp slurry layer from the first mould to the first transfer tool.

[0055] During movement of the first transfer tool from the first mould to the second mould the first moulding surface portion may be in contact with the pulp slurry layer and the second moulding surface portion may be free.

[0056] During transfer of the pulp slurry layer from the first mould to the second mould a vacuum may be drawn through the first transfer tool such that at least some water is evacuated from the pulp slurry layer.

[0057] The vacuum may be applied when the pulp slurry layer is received by the first transfer tool (ie transferred from the first mould to the first transfer tool), and / or during movement of the transfer tool from the first mould to the second mould.

[0058] The pulp slurry layer transferred to the second mold may present a first pulp slurry layer portion and a second pulp slurry layer portion, wherein the first pulp slurry layer portion and the second pulp slurry layer portion are juxtaposed and the first pulp slurry layer portion has a higher or lower moisture level than the second pulp slurry layer portion.

[0059] Picking up the pulp slurry layer may be achieved by dipping the porous first product side of the pick-up press tool into a bath containing pulp slurry while simultaneously drawing a vacuum through the porous first product side of the pick-up press tool such that the pulp slurry layer is applied to the product side.

[0060] A pick-up pressing tool may be moved vertically upward from the bath into contact with a mating pressing tool.

[0061] Alternatively, the pulp slurry layer is applied to the porous first product face of the pick-up press tool by spraying or pouring.

[0062] During the pick-up of the pulp slurry layer, the first pressure at the rear side of the porous first product face is 300-700 mbarA, preferably 400-600 mbarA.

[0063] In the first molding step, a second pressure at the rear side of the porous product face of the first mold may be lower than a third pressure at the rear side of the porous product face of the second mold in the second molding step.

[0064] The second pressure may be 1-99%, preferably 50-99% or 90-99% of the third pressure.

[0065] The second pressure may be 200-900 mbarA, preferably 300-800 mbarA.

[0066] In the first shaping step, the second product side of the first mould, which cooperates with the pressing tool, may be heated to about 150-400°C, preferably 200-300°C.

[0067] In the first forming step, the porous first product side of the pick-up pressing tool of the first mould may be heated to about 100-150°C.

[0068] The porous first product side of the pick-up press tool may be heated in the first forming step to achieve an additional drying effect of the pulp slurry layer or to keep the fibers warm for formability.

[0069] In the first forming step, the pulp slurry may be laminated onto the second product surface of the first mold with a pressure of about 390-1570 kPa, preferably 580-1170 kPa.

[0070] In the first forming step, the pulp slurry may be layered on the second product surface of the first mold during a first pressing time of 0.1-4.0 seconds, preferably 0.5-2.0 seconds.

[0071] In the first pressing step, the initial moisture content of the pulp slurry layer may be 70-90% by weight, and the final moisture content may be 45-65% by weight, preferably about 50-60% by weight.

[0072] The third pressure may be 200-900 mbarA, preferably 300-800 mbarA.

[0073] In the second forming step, at least one of the product faces of the second mould may be heated to about 110-400°C, preferably 200-300°C.

[0074] In the second forming step, the pulp slurry may be laminated onto the second product surface of the second mold with a pressure of about 390-1570 kPa, preferably 580-1170 kPa.

[0075] In the second forming step, the pulp slurry may be layered on the second product surface of the second mold during a second pressing time of 0.1-4.0 seconds, preferably 0.5-2.0 seconds.

[0076] In the second forming step, the pulp slurry layer has an initial moisture content of about 45-65% by weight, preferably about 50-60% by weight, and a final moisture content of about 25-40% by weight, preferably about 30-35% by weight.

[0077] The method may further include transferring the pulp slurry layer to the porous product surface of the first pressing tool of the third mold, and in a third subsequent forming step, pressing the pulp slurry layer on the second product surface of the second pressing tool of the third mold, while heating the pulp slurry layer and drawing a vacuum through the porous product surface of at least one of the first pressing tool and the second pressing tool of the third mold.

[0078] Optionally, a washing step of the pulp slurry layer may be performed before the third forming step.

[0079] The transferring of the pulp slurry layer may be performed by a second transferring tool.

[0080] The third pressure at the rear side of the porous product face of the second mold may be lower than the fourth pressure at the rear side of the porous product face of the third mold.

[0081] The fourth pressure may be 200-900 mbarA, preferably 300-800 mbarA.

[0082] In the third molding step, at least one of the product surfaces of the third mold may be heated to about 100-300°C, preferably 200-280°C.

[0083] In the third forming step, the pulp slurry may be layered on the second product surface of the third mold with a pressure of about 390-1570 kPa, preferably 580-1170 kPa.

[0084] In the third forming step, the pulp slurry may be layered on the second product surface of the third mold during a third pressing time of 0.1-4.0 seconds, preferably 0.5-2.0 seconds.

[0085] In the third forming step, the initial moisture content of the pulp slurry layer may be about 25-45% or 25-40% by weight, preferably about 30-40% or 30-35% by weight, and the final moisture content may be less than about 5% by weight, preferably less than about 1% by weight.

[0086] According to a third aspect of the present invention, based on the above, there is provided a method of forming a receiving seat, wherein a non-molding space is provided at respective portions of a pressing tool and a transfer tool corresponding to an opening portion of the receiving seat.

[0087] The receptacle may be a container, cup, jar, can, bottle, etc. suitable for containing solid, liquid and / or gaseous contents. The receptacle may be used as a container for a variety of different products, such as personal care products, household care products, food or beverages, etc.

[0088] The opening portion may present an edge of the receptacle.

[0089] According to a fourth aspect of the present invention, there is provided a system for producing a 3D moulded product from a pulp slurry, the system comprising: a pick-up pressing device according to what has been described above and a second pair of mating pressing tools.

[0090] The second pair of cooperating pressing tools may each be mounted to a respective tool holder. At least one of the tools of the second pair of cooperating pressing tools may present a porous product face. At least one of these tools may be connected to a vacuum source.

[0091] The system may further include a second transfer tool and a third pair of mating pressing tools.

[0092] The second transfer tool may be adapted to transfer the layer of pulp slurry from the second pair of pressing tools to the product side of the third pair of pressing tools.

[0093] The second transfer tool may be connected to a pressure regulator capable of generating a vacuum or air pressure.

[0094] A second transfer tool can also be mounted on the transfer tool holder.

[0095] The third pair of cooperating pressing tools may each be mounted to a respective tool holder. At least one of the tools of the third pair of cooperating pressing tools may present a porous product face. At least one of these tools may be connected to a vacuum source. BRIEF DESCRIPTION OF THE DRAWINGS

[0096] Figure 1a to Figure 1d A pair of pick-up and press tools of a pick-up and press device is schematically shown.

[0097] Figure 2a to Figure 2d A transfer tool of a pick-up pressing device is schematically shown.

[0098] Figure 2e A pair of pressing tools is schematically shown.

[0099] Figure 2f to Figure 2g Two different embodiments of a transfer tool for a pick-up and hold-down device are schematically shown.

[0100] Figure 3 The production process is schematically shown. DETAILED DESCRIPTION

[0101] Figure 1a A pick-up pressing tool 10 , a mating pressing tool 20 and a container 1 with a pulp slurry 2 are schematically illustrated.

[0102] The pick-up pressing tool 10 is adapted both to pick up the pulp slurry layer 3 from the pulp slurry 2 and to press the pulp slurry layer 3 in a first pressing step.

[0103] The pick-up press tool 10 is mounted to a tool holder 11 which together with the pick-up press tool defines a vacuum chamber 12 which is connected to a pressure regulator P1. The pressure regulator may have the capability to selectively generate at least a partial vacuum (i.e., air pressure lower than ambient air pressure) and / or an air pressure higher than ambient air pressure.

[0104] The pick-up pressing tool may be self-supporting, meaning that the tool wall portion of the tool is sufficiently rigid and has a sufficiently high melting point that the tool wall portion does not require any supporting structure to maintain its shape during operation.

[0105] The pick-up press tool 10 presents a porous first product face, ie a porous surface of the tool adapted to be in contact with a pulp slurry layer or a pulp product during forming of such a pulp product. The porosity of the porous first product face may be 10-90%.

[0106] The porous first product side may further present pores with a hole size of 0.1-0.7 mm in diameter, preferably 0.25-0.6 mm.

[0107] like Figure 1a As shown, the pressing tool 20 may also be mounted to a tool holder 21. The tool holder 21 may define a vacuum chamber 21 together with the pressing tool 20. The vacuum chamber 21 may be connected to a pressure regulator P2. The pressure regulator may have the ability to selectively generate at least a partial vacuum (i.e., air pressure below ambient air pressure) and / or an air pressure above ambient air pressure.

[0108] The pressing tool 20 presents a second product face. The second product face may be porous or non-porous. Alternatively, the second product face may present a porous portion and a non-porous portion.

[0109] The pick-up pressing tool 10 and the pressing tool 20 are vertically movable relative to each other.

[0110] In a first relative position of the pressing tools 10, 20, at least one of the product faces is positioned to receive the pulp slurry 3, which may be in liquid form, onto its product face, see Figure 1a .

[0111] In a second relative position of the pressing tools 10, 20, the product faces are pressed towards each other for pressing the pulp slurry layer, see Figure 1d .

[0112] Therefore, the pick-up pressing tool 10 may maintain its orientation relative to the pressing tool 20 from the picking up of the pulp slurry layer to the pressing of the pulp slurry layer.

[0113] Further, the pick-up pressing tool 10 can be moved in the direction Y1 for starting the step of picking up the pulp slurry layer 3 from the container 1 with the pulp slurry 2, see Figure 1a .

[0114] Further, the pick-up pressing tool 10 can be moved in the direction Y2 for starting the step of pressing the pulp slurry layer 3 in the first pressing step, see Figure 1c .

[0115] Alternatively or additionally, the pressing tool 20 may be moved in the direction Y1 for initiating a first pressing step.

[0116] Figure 1b The pick-up press tool 10 is schematically shown immersed in a container 1 containing a pulp slurry 2. When the pick-up press tool is immersed in the pulp slurry 2, the pressure regulator P1 can generate a vacuum so that the pulp fibers 3 are sucked towards the product side of the pick-up press tool 10.

[0117] Figure 1c It is schematically illustrated that the picking up pressing tool 10 moves the pulp fibers 3 towards the pressing tool 20, ie starts the first pressing step.

[0118] During the movement, the pressure regulator P1 can generate a vacuum, thereby making the pulp fibers 3 stick to the product side of the pick-up pressing tool 10 .

[0119] Figure 1d The pick-up pressing tool 10 and the pressing tool 20 are schematically illustrated in a pressing position. Hence, the pick-up pressing tool 10 and the pressing tool 20 may form a pressing arrangement adapted to perform a first pressing step of the pulp slurry layer 3.

[0120] The pick-up pressing tool 10 and the pressing tool 20 and their associated tool holders 11, 21 can be moved relative to each other between an open position and a pressing position. In the pressing position, Figure 1d As shown, the tools 10, 20 are pushed towards each other, thereby pressing the pulp slurry layer between the product faces of the respective tools 10, 20, so that a pulp product 3' is formed.

[0121] like Figure 1d As shown, one or both of the pick-up pressing tool and the pressing tool may be equipped with a heating element 13, 23. The heating element is adapted to supply heat to the product face of the tool.

[0122] The heating element may be powered by energy suppliers E1 , E2. Further, the heating element may be controlled by a controller C.

[0123] The heating element may be an electric heating element, a hot air or liquid heating element or an induction heating element.

[0124] When in the pressing position, heat may be supplied by one or both of the heating elements 13 , 23 .

[0125] During pressing of the pulp product 3', one or both of the pressure regulators P1 , P2 may provide a vacuum to assist in evacuating water vapor from the pulp product 3'.

[0126] As an alternative, one of the pressure regulators P1 , P2 may provide a vacuum while the other pressure regulator provides a pressure above the ambient air pressure.

[0127] Optionally, during the pressing process, hot air or steam can be introduced through the tool ( Figure 1d ).

[0128] As an alternative to immersing the pick-up press tool in the pulp slurry, the pulp slurry may be applied by a coating operation such as spraying or pouring. Optionally, during the coating operation, the pressure regulator P1 may create a vacuum so that the pulp fibers 3 are sucked towards the product side of the pick-up press tool 10 .

[0129] It should also be noted that two or more consecutive pressing steps may be used, for example to gradually form all or part of the product 3', 3", 3'", and / or to apply additional features to the product, such as coatings, decorations, etc.

[0130] Figure 2a to Figure 2d A first transfer tool 30 is shown, which can be used to transfer the product 3' from the first pressing tool 10, 20 to the second pair of pressing tools 40, 50, see Figure 2a to Figure 2e .

[0131] The first transfer tool 30 may be connected to a third pressure regulator P3 capable of generating vacuum or air pressure. The transfer tool 30 may also be mounted on a transfer tool holder 31 to define a vacuum chamber 32, which is connected to the third pressure regulator P3.

[0132] During the transfer of the pulp fibers, the first pressure regulator P1 may generate an air pressure higher than the ambient pressure to release the pulp fibers from the pick-up press tool 10 .

[0133] Alternatively, or in addition, the third pressure regulator P3 may generate a vacuum so that the pulp fibers are received by the transfer tool 30 .

[0134] The first transfer tool may be equipped with a heating element (not shown). The heating element is suitable for supplying heat to the product face of the first transfer tool. The heating element may be powered by an energy supplier. Further, the heating element may be controlled by a controller C.

[0135] The heating element may be an electric heating element, a hot air or liquid heating element or an induction heating element.

[0136] The first transfer tool 30 is suitable for forming a part of the product 3', such as Figure 2a to Figure 2d What is shown.

[0137] The first transfer tool 30 may present a porous product face.

[0138] The porosity of the porous product surface of the first transfer tool 30 may be 10-90%.

[0139] The porous product face of the first transfer tool 30 may present holes with a hole size of 0.1-0.7 mm in diameter, preferably 0.25-0.6 mm.

[0140] like Figure 2a and Figure 2b As illustrated, the first transfer tool 30 may include a first molding surface portion 34 and a second molding surface portion 35 .

[0141] like Figure 2a As illustrated, the first forming surface portion 34 can be configured to conform to the porous first product face first portion 14 such that a forming gap 80 is defined therebetween. The forming gap 80 can define a desired pulp slurry layer thickness.

[0142] The second molding surface portion 35 may be configured to diverge from the porous first product face second portion 15 so that the non-molding space 90 is defined by the second molding surface portion 35 and the porous first product face second portion 15. The thickness of the non-molding space 90 may be greater than the molding gap 80.

[0143] The non-forming space 90 may be configured to provide contact between only one pulp slurry layer layer and one of the second forming surface portion 35 and the second portion 15 of the porous first product face.

[0144] The non-forming space 90 may present a space between the second forming surface portion 35 and the second portion 15 of the porous first product surface, which is greater than 20 times the thickness of the forming gap 80 , preferably greater than 15 times, 10 times or 5 times the thickness of the forming gap 80 .

[0145] As seen in the pressing direction, the non-forming space 90 may be provided at the innermost portion of the female mold and / or the distal end portion of the male mold, see Figure 2f .

[0146] Alternatively, the non-forming space 90 may be provided at the outermost portion of the female mold and / or the distal end portion of the male mold as seen in the pressing direction, see Figure 2g .

[0147] The female mold can be a pick-up pressing tool or a pressing tool. The male mold can be a transfer tool.

[0148] The forming gap 80 may present a thickness that is small enough so that both the forming surface portion 34 and the first portion 14 of the porous first product face contact the respective pulp slurry layers.

[0149] The forming gap 80 may be configured to provide a pressure on the pulp product 3' that is greater than ambient pressure.

[0150] Thus, as the pulp product 3' is transferred from the porous first product face of the pick-up pressing tool 10 to the first transfer tool 30, see Figure 2a A pressure greater than the ambient pressure may be applied to a portion of the pulp product 3' in contact with both the shaping surface portion 34 of the first transfer tool 30 and the first portion 14 of the porous first product face.

[0151] The first shaping surface portion 34 may be adapted to come into contact with a portion of the product 3' during transfer of the product.

[0152] The first forming surface portion 34 may present a contact surface area sufficient to receive and hold the pulp product 3' at the first transfer tool during movement of the first transfer tool.

[0153] The first forming surface portion 34 may present a contact surface area corresponding to 10-99.9%, preferably 25-95%, of the total area of ​​the porous first product face.

[0154] like Figure 2bAs illustrated, during the movement of the first transfer means from the first pressing means 10, 20 to the second pair of pressing means 40, 50 at least a part of the pulp product 3' may be free.

[0155] Thus, during movement of the first transfer tool transferring the pulp product 3' from the first pair of pressing tools 10, 20 to the second pair of pressing tools 40, 50, the first forming surface portion 34 may be in contact with the pulp slurry layer and the second forming surface 35 may be free.

[0156] The shape of the porous product surface of the first transfer tool 30 can substantially match the shape of the product surface of the pressing tools of the second pair of pressing tools, see Figure 2c .

[0157] Thus, as the pulp product 3' is transferred to the product side of the pressing tool 40, at least one free portion of the pulp product 3' may come into contact with the second shaping surface portion 35 of the first transfer tool 30. As the pulp product 3' is transferred from the first transfer tool 30 to the product side of the pressing tool 40, at least one free portion of the pulp product 3' may be formed, see Figure 2c .

[0158] Next, the first transfer tool 30 can be removed from the pressing tool 40, as shown in FIG. Figure 2d Next, the pulp product 3" may be pressed in a second pressing step using a second pair of pressing tools 40, 50, as shown. Figure 2e What is shown.

[0159] When the first transfer tool 30 transfers the product from the pick-up pressing tool 10 ( Figure 2a ), the third pressure regulator P3 can generate a vacuum so that the pulp fibers are received by the transfer tool 30. Additionally or alternatively, a vacuum can be generated during the movement of the first transfer tool 30 from the first pair of pressing tools 10, 20 to the second pair of pressing tools 40, 50. Thus, water can be evacuated from the product during the transfer.

[0160] Because the first transfer tool 30 is adapted such that at least a portion of the pulp product 3' can be in contact with the porous product surface of the first transfer tool 30 during transfer, and at least one portion of the pulp product 3' can be free, i.e. not in contact, different levels of water can be emptied from different portions of the pulp product 3'.

[0161] Therefore, the pulp product 3' transferred to the second pair of pressing tools 40, 50 can present a first pulp slurry layer portion and a second pulp slurry layer portion, wherein the first pulp slurry layer portion and the second pulp slurry layer portion are juxtaposed and the first pulp slurry layer portion has a higher or lower moisture level than the second pulp slurry layer portion.

[0162] The second transfer means may be used to transfer the pulp product 3'" from the second pair of pressing tools 40, 50 to a third pair of pressing tools (not shown).

[0163] The second transfer tool may be designed substantially the same as the first transfer tool, or have a different design. Thus, the second transfer tool may be used to transfer the product from the second pair of pressing tools to the third pair of pressing tools, or alternatively, both transfer the product and form part of the product.

[0164] According to the present invention, according to Figure 1a to Figure 1d and Figure 2a to Figure 2e What has been described, there is provided a pick-up press apparatus for use in producing a 3D moulded product from a pulp slurry, the pick-up press apparatus comprising: a pick-up press tool, a press tool, a vacuum source connected to the pick-up press tool, and a first transfer tool.

[0165] According to the present invention, there is also provided a method of producing a 3D moulded product from a pulp slurry.

[0166] In one embodiment, according to Figure 1a to Figure 1d and Figure 2a to Figure 2c Follow the steps already described.

[0167] The 3D molded product may be a receptacle such as a container, cup, jar, can, bottle, etc. suitable for containing solid, liquid and / or gaseous contents.

[0168] Next, the non-molding space 90 may be provided at respective portions of the pressing tool and the transfer tool corresponding to the opening portion of the receiving seat. The opening portion may present an edge of the receiving seat.

[0169] See also Figure 3 , the production process will now be described.

[0170] In a first step 101, a pulp slurry layer is provided, for example as described in reference Figure 1a The invention relates to a method for producing a first mold for producing a paper pulp slurry, wherein the pulp slurry layer is applied to a porous first product side of a first mold. This can be achieved by providing a first mold comprising a pick-up pressing tool presenting a porous first product side and a pressing tool presenting a second product side. The second product side may be porous or non-porous. Alternatively, the second product side may present a porous portion and a non-porous portion.

[0171] In the step of applying the pulp slurry layer to the porous first product side, the pick-up pressing tool may be adapted to pick up the pulp slurry layer from the pulp slurry.

[0172] The picking up of the pulp slurry layer may be performed by dipping a porous pick-up press tool of the first mould into the pulp slurry, wherein a vacuum is applied to the back side of the pick-up press tool.

[0173] During the pick-up of the pulp slurry layer, the first pressure at the rear side of the porous first product face may be 300-700 mbarA (absolute millibars), preferably 400-600 mbarA.

[0174] The flow rate through the tool can be between 50 and 1000 m 3 Preferably, the flow rate may be between 1000 and 30 000 m2 per square meter of the porous first product surface of the tool. 3 / h.

[0175] Thus, a vacuum may be drawn through the porous first product side of the pick-up pressing tool so that a layer of pulp slurry may be applied to the porous first product side.

[0176] The surface porosity of the porous first product face of the pick-up pressing tool may be 10-90%, with the hole size being 0.1-0.7 mm in diameter, preferably 0.25-0.6 mm.

[0177] Alternatively, the pulp slurry may be applied to the pick-up press tool by a coating operation such as spraying or pouring. Optionally, during the coating operation, a vacuum may be drawn through the porous first product face of the pick-up press tool, thereby causing the pulp fibers to be drawn toward the product face of the pick-up press tool.

[0178] In a second step 102, a pulp slurry layer is pressed in a first mold. Thus, a pick-up pressing tool with the pulp slurry layer is lifted from the pulp slurry or its initial application position and moved towards the pressing tool, whereby the pulp slurry layer is pressed onto the second product face of the pressing tool. This can be performed in one vertical movement, so that the pick-up pressing tool is lifted and moved directly to the pressing tool.

[0179] Alternatively, the pick-up pressing tool may be lifted from the pulp slurry and the pressing tool moved to the pick-up pressing tool.

[0180] Alternatively, both the pick-up pressing tool and the pressing tool may be moved towards each other in vertical direction.

[0181] In this first pressing step 102, a pressure below ambient pressure is applied at the back side of the porous product face of the first mould, thereby creating a vacuum at the back side of the porous product face, thereby causing solvent vapour, such as steam, to be drawn through the tool.

[0182] The pressure applied to the back side of the porous product face may be on the order of magnitude of a low or medium vacuum level. That is, the first pressure may be 200-900 mbarA, preferably 300-800 mbarA.

[0183] The flow rate through the tool can be between 50 and 1000 m 3 Preferably, the flow rate may be between 1000 and 30 000 m2 per square meter of the porous product surface of the tool. 3 / h.

[0184] The second product side of the pressing tool of the first mould may be heated to about 150-500°C, preferably 150-400°C, 200-500°C, 200-400°C, or 200-300°C, in most cases 240-280°C.

[0185] The porous first product side of the pick-up pressing tool of the first mould may be heated to about 100-150°C.

[0186] The pressing pressure between the pick-up pressing tool and the product face of the pressing tool may be in the order of about 390-1570 kPa, in most cases 580-1170 kPa.

[0187] The pressing pressure may be applied during a first pressing time of 0.1-4.0 seconds, preferably 0.5-2.0 seconds. In most arrangements, a pressing time on the order of 0.5-1.5 seconds is sufficient, typically also 0.5-1 second.

[0188] Typically, in this first step, the initial moisture content of the pulp slurry layer is 70-90% by weight, and after the pressing step has been performed, the final moisture content may be 45-65% by weight, typically about 50-60% by weight.

[0189] After the first pressing step 102, the pulp slurry layer (now having had a large amount of its solvent removed) can be transferred 103 to a second pressing tool. The transfer can be performed by a transfer tool, as described above with respect to Figure 2a to Figure 2e Thus, at least a portion of the pulp slurry layer may be formed during the transfer.

[0190] During the transfer step, vacuum may be applied to the back side of the transfer tool wall so that the pulp slurry layer is held to the transfer tool wall.To release the pulp slurry layer from the transfer tool wall, pressurized air may alternatively be applied to the back side of the transfer tool wall.

[0191] Alternatively, or in addition, a vacuum may be applied to the rear side of the porous product face of the second mould so that the pulp slurry layer is received by the second mould.

[0192] During transfer, the product side of the transfer tool may be heated to about 100-150°C.

[0193] Thereby, an additional drying effect of the pulp slurry layer may be achieved and / or the pulp slurry layer may maintain the fibers warm for formability.

[0194] The second mold may include a pair of cooperating pressing tools, one of which may have a porous product face that contacts the pulp slurry layer and through which a vacuum may be drawn.

[0195] The second mold may include a first pressing tool presenting a porous product side and a second pressing tool presenting a second product side. The second product side may be porous or non-porous. Alternatively, the second product side may present a porous portion and a non-porous portion.

[0196] The transferring 103 may be performed by transferring the pulp slurry layer from the first mould to the porous product side of the first pressing tool of the second mould by means of a transfer tool.

[0197] In a second pressing step 104, the pulp slurry layer may be pressed in a second mold. Next, the pulp slurry layer may be pressed on a second product side of a second pressing tool of the second mold. In this second pressing step 104, a pressure lower than the ambient pressure is applied at the back side of the porous product side of the mold, thereby creating a vacuum at the back side of the porous product side, so that solvent vapor (such as steam) is drawn through the tool.

[0198] The porosity of the porous product face of the second mould may be 25-50%, with a hole size of 0.1-1.2 mm, preferably 0.25-1.0 mm.

[0199] However, in the second pressing step 104 , the pressure applied at the rear side of the porous product face of the second mold may be higher than the pressure provided in the first pressing step 102 .

[0200] In particular, the pressure provided in the first pressing step 102 may be 1-99%, preferably 50-99%, 90-99%, 95-99%, or 99-99.9% of the pressure provided in the second pressing step 104 .

[0201] In the second pressing step, the absolute pressure applied to the back side of the porous product face of the second mould may be 200-900 mbarA, preferably 300-800 mbarA, but always greater than the absolute pressure in the first pressing step.

[0202] The flow rate through the tool can be between 50 and 1000 m 3Preferably, the flow rate may be between 1000 and 30 000 m2 per square meter of the porous product surface of the tool. 3 / h.

[0203] At least one of the product faces of the second mould may be heated to about 110-500° C., preferably 110-400° C., 150-500° C., 150-400° C., 200-500° C., 200-400° C., or 200-300° C., in most cases 240-280° C. Typically, all product faces constituting the second mould and contacting the pulp slurry layer may be heated.

[0204] The pressing pressure between the product faces of the first pressing tool and the second pressing tool of the second die may be in the order of about 390-1570 kPa, and in most cases 580-1170 kPa.

[0205] The pressing pressure may be applied during a second pressing time of 0.1-4.0 seconds, preferably 0.5-2.0 seconds. In most arrangements, a pressing time on the order of 0.5-1.5 seconds is sufficient, typically also 0.5-1 second.

[0206] Typically, in this second pressing step, the initial moisture content of the pulp slurry layer may be about 45-65% by weight, typically about 50-60% by weight.

[0207] The final moisture content may be about 25-40% by weight, preferably about 30-35% by weight.

[0208] After the second pressing step 104, the pulp slurry layer (now having a large amount of its solvent removed) can be transferred 105 to a third pressing mold. The transfer 106 can be performed in the same manner and with similar equipment as the first transfer step 103. Thus, at least a portion of the pulp slurry layer can be formed during the transfer.

[0209] Alternatively, the apparatus may be different so that the second transfer tool transfers the pulp slurry layer without forming it.

[0210] The third pressing die may be designed substantially the same as the second pressing die.

[0211] The third mold may include a pair of cooperating pressing tools, one of which may have a porous product face that contacts the pulp slurry layer and through which a vacuum may be drawn.

[0212] The third mold may include a first pressing tool presenting a porous product side and a second pressing tool presenting a second product side. The second product side may be porous or non-porous. Alternatively, the second product side may present a porous portion and a non-porous portion.

[0213] In a third pressing step 106, the pulp slurry layer may be pressed in a third mold. Next, the pulp slurry layer may be pressed on a second product face of a second pressing tool of the third mold. In this third pressing step 106, a pressure lower than the ambient pressure is applied at the back side of the porous product face, thereby creating a vacuum at the back side of the porous product face, thereby causing solvent vapor (such as steam) to be drawn through the tool.

[0214] The porosity of the porous product surface of the third mould may be 25-50%, with a hole size of 0.1-1.2 mm, preferably 0.25-1.0 mm.

[0215] However, in the third pressing step 106 , the pressure applied at the rear side of the porous product face of the third mold may be higher than the pressure provided in the first pressing step 104 .

[0216] In particular, the pressure provided in the second pressing step 104 may be 1-99%, preferably 50-99%, 90-99%, 95-99%, or 99-99.9% of the pressure provided in the third pressing step 106 .

[0217] In the third pressing step, the absolute pressure provided at the back side of the porous product face of the third mould may be 200-900 mbarA, preferably 300-800 mbarA, but always greater than the absolute pressure in the second pressing step.

[0218] The flow rate through the tool can be between 50 and 1000 m 3 Preferably, the flow rate may be between 1000 and 30 000 m2 per square meter of the porous product surface of the tool. 3 / h.

[0219] At least one of the product faces of the third mould may be heated to about 100-400° C., preferably 100-300° C., 150-400° C., 150-300° C., 200-300° C., or 200-280° C., in most cases 240-280° C. Typically, all product faces constituting the third mould and contacting the pulp slurry layer may be heated.

[0220] The pressing pressure between the product faces of the third die may be in the order of about 390-1570 kPa, and in most cases 580-1170 kPa.

[0221] The pressing pressure may be applied during a third pressing time of 0.1-4.0 seconds, preferably 0.5-2.0 seconds. In most arrangements, a pressing time on the order of 0.5-1.5 seconds is sufficient, typically also 0.5-1 second.

[0222] Typically, in this third pressing step, the initial moisture content of the pulp slurry layer may be about 25-45% or 25-40% by weight, preferably about 30-40% or 30-35% by weight, and the final moisture content may be less than about 5% by weight, preferably less than about 1% by weight.

[0223] After the third pressing step 106, the pulp slurry layer (now having most of its solvent removed) can be transferred 107 away from the machine.

[0224] Optionally, additional steps may be performed on the substantially dried product, such as surface treatment, cutting or printing. The product may then be packaged, stored, and shipped.

[0225] It should be noted that the third pressing step 106, and therefore its associated transfer step 105, is optional. Therefore, the process can be followed by the output step 107 immediately after the second pressing step 104 and then end.

[0226] Therefore, in the first pressing step, the initial moisture content of the pulp slurry layer may be 70-90% by weight, and the final moisture content may be 25-50% by weight, preferably about 30-35% by weight.

[0227] In the second pressing step, the initial moisture content of the pulp slurry layer may be about or 25-50% by weight, preferably about or 30-35% by weight, and the final moisture content may be less than about 5% by weight, preferably less than about 1% by weight.

[0228] Further, the method may comprise at least one optional washing step of the pulp slurry layer. The washing step may be performed after the transfer step 103 and before the second pressing step 104 and / or after the transfer step 105 and before the third pressing step 106.

[0229] Further, the method may comprise at least one step of applying a laminate or coating to the pulp slurry layer or pulp product. The laminate or coating may be applied between the first pressing step and the second pressing step, or between the second pressing step and the third pressing step, or after the third pressing step.

[0230] It should be noted that the vacuum source provided must be sized to provide a flow rate sufficient to evacuate the amount of steam generated during the heating / pressing step and also contain the liquid water drawn out by the vacuum applied to the respective mould.

Claims

1. A method for producing a 3D molded product from a pulp slurry, the method comprising: applying a layer of pulp slurry in liquid form to a porous first product side of a pick-up pressing tool (10) of a first mould; In a first forming step, the pulp slurry layer on the porous first product surface of the pick-up pressing tool (10) is pressed onto the second product surface of the matching pressing tool (20) of the first mold while heating the pulp slurry layer; transferring the pulp slurry layer to a porous product side of a first pressing tool of a second mold (40, 50); In a second subsequent forming step, the pulp slurry layer is pressed onto a second product surface of a second pressing tool of the second mold (40, 50) while heating the pulp slurry layer, Wherein at least a portion of the pulp slurry layer is formed during transfer to the first pressing tool of the second mould (40, 50).

2. The method of claim 1, wherein: The transfer of the pulp slurry layer from the first mould (10, 20) to the second mould (40, 50) is performed by means of a first transfer tool (30), the first transfer tool comprising a first moulding surface portion (34) and a second moulding surface portion (35), wherein, during transfer of the pulp slurry layer from the first mould (10, 20) to the first transfer tool (30), the first forming surface portion (34) conforms to the first portion (14) of the porous first product face of the first mould so as to define a forming gap (80) therebetween, the forming gap (80) defining a desired pulp slurry layer thickness, and The second molding surface portion (35) radiates from the second portion (15) of the porous first product surface of the first mold, so that the non-molding space (90) is defined by the second molding surface portion (35) and the second portion (15) of the porous first product surface of the first mold, and the thickness of the non-molding space (90) is greater than the molding gap.

3. The method according to claim 1 or 2, wherein: The transfer of the pulp slurry layer from the first mold (10, 20) to the second mold (40, 50) is performed by a first transfer tool (30), wherein during the transfer of the pulp slurry layer from the first mold (10, 20) to the second mold (40, 50), a vacuum is drawn by the first transfer tool (30) so that at least some water is emptied from the pulp slurry layer.

4. The method according to claim 1 or 2, wherein: The pulp slurry layer transferred to the second mold (40, 50) presents a first pulp slurry layer portion and a second pulp slurry layer portion, wherein the first pulp slurry layer portion and the second pulp slurry layer portion are juxtaposed, and the moisture content level of the first pulp slurry layer portion is higher or lower than that of the second pulp slurry layer portion.

5. The method according to claim 1 or 2, wherein: The pulp slurry layer is applied to the porous first product face of the pick-up press tool (10) by spraying or pouring.

6. The method according to claim 1 or 2, wherein: In the first forming step, the second product surface of the mating pressing tool (20) of the first mold is heated to 150-400°C.

7. The method according to claim 1 or 2, wherein: In the first forming step, the second product surface of the mating pressing tool (20) of the first mold is heated to 200-300°C.

8. The method according to claim 1 or 2, wherein: A vacuum is drawn through the porous product face of at least one of the tools (10, 20) while the pressing of the first forming step is performed.

9. The method according to claim 1 or 2, wherein: In the first forming step, the pulp slurry is laminated onto the second product surface of the first mold with a pressure of 390-1570 kPa.

10. The method according to claim 1 or 2, wherein: In the first forming step, the pulp slurry is layered on the second product surface of the first mold during a first pressing time of 0.1-4.0 seconds.

11. The method according to claim 1 or 2, wherein: In the second molding step, at least one of the product surfaces of the second mold (40, 50) is heated to 110-400°C.

12. The method according to claim 1 or 2, wherein: In the second molding step, at least one of the product surfaces of the second mold (40, 50) is heated to 200-300°C.

13. The method according to claim 1 or 2, wherein: The pressing of the second forming step is performed while simultaneously drawing a vacuum through the porous product surface of at least one of the first pressing tool and the second pressing tool of the second mold (40, 50).

14. The method according to claim 1 or 2, wherein: In the second forming step, the pulp slurry is laminated onto the second product surface of the second mold with a pressure of 390-1570 kPa.

15. The method according to claim 1 or 2, wherein: In the second forming step, the pulp slurry is layered on the second product surface of the second mold during a second pressing time of 0.1-4.0 seconds.

16. The method of claim 1 or 2, further comprising transferring the pulp slurry layer to the porous product surface of a first pressing tool of a third mold, and in a third subsequent forming step, pressing the pulp slurry layer onto the second product surface of a second pressing tool of the third mold, while heating the pulp slurry layer and drawing a vacuum through the porous product surface of at least one of the first pressing tool and the second pressing tool of the third mold.

17. The method of claim 16, wherein: In the third molding step, at least one of the product surfaces of the third mold is heated to 100-300°C.

18. The method of claim 16, wherein: In the third molding step, at least one of the product surfaces of the third mold is heated to 200-280°C.

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