Tool and method for producing three-dimensional molded pulp product

Abstract

To provide an improved tool and method for forming a three-dimensional molded pulp product.SOLUTION: There is provided a tool for producing a three-dimensional molded product from a pulp slurry, comprising a pair of molds having respective product faces, which are configured to face each other and to press a pulp layer therebetween, and the product faces providing a three-dimensional shape for molding the three-dimensional molded product, the product faces presenting respective outer product face edges, defining an outermost limit of a forming area of the mold. At least one of the product faces, as seen from the product face edge and inwardly towards a center of gravity of the product face, presents an outer zone (Z1) having effectively no porosity, and an inner zone (Z4) having a porosity of 40 to 75%, wherein a first intermediate zone (Z2) is arranged between the outer zone (Z1) and the inner zone (Z4), and has a porosity that is greater than that of the outer zone (Z1) and less than that of the inner zone (Z4).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to tools and methods for producing molded pulp products. The methods are particularly suited for 3D forming of products from pulp slurries. Such products may include trays, cups, plates, and various containers for packaging. [Background technology]

[0002] From WO2016101976 it is known a method for producing a product from a pulp slurry by applying a layer of the slurry to a porous mould and removing water from the slurry by simultaneously heating and pressing the slurry layer whilst drawing a vacuum through a mould wall the opposite side of which is in contact with the slurry layer.

[0003] As disclosed in WO2016101976, the molding process may be carried out in two or more successive press steps, which is advantageous as it reduces the cycle time compared to a single press step process, thus increasing the throughput of the manufacturing process.

[0004] The production of pulp products using porous dies is associated with a variety of challenges due to the behavior of the pulp when interacting with the porous dies.

[0005] One particular problem addressed here is the formation of "whiskers" at the interior corners of the mold. Such "whiskers" are the result of the accumulation of excessive amounts of pulp. Such whiskers have a detrimental effect on subsequent forming steps, as well as the appearance of the final product.

[0006] There is a need to reduce this "whisker formation." [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2016101976 Brochure Summary of the Invention

[0008] It is an object of the present disclosure to provide improved tools and methods for forming 3D molded pulp products.

[0009] The invention is defined by the accompanying independent claims, and embodiments are set out in the accompanying dependent claims, as well as the following description and drawings.

[0010] According to a first aspect, there is provided a tool for producing a 3D molded product from a pulp slurry, comprising a pair of dies having respective product faces facing each other and configured to press a pulp layer therebetween, said product faces providing a 3D shape for forming the 3D molded product, said product faces presenting respective outer product end faces and defining the outermost limits of the forming areas of at least one, preferably both, of the dies, at least one of the product faces presenting, looking inwardly from the product end face towards the centre of gravity of the product face, an outer zone having virtually no porosity and an inner zone having a porosity of 40-75%, and a first intermediate zone disposed between the outer and inner zones and having a porosity higher than the porosity of the outer zone and lower than the porosity of the inner zone.

[0011] The term "porosity" is defined as the ratio of the pore surface to the total area of ​​a given region of a zone.

[0012] By gradually reducing the porosity in the edge regions, the vacuum created in the outermost portion of the mold is gradually reduced, thus preventing or eliminating the accumulation of excessive amounts of pulp in the outermost portion of the mold.

[0013] The outer zone may exhibit a porosity of less than 1%, preferably less than 0.5% or less than 0.1%.

[0014] The first intermediate zone may exhibit a porosity that is 25-75% of the porosity of the inner zone.

[0015] The product surface may exhibit a second intermediate zone having a porosity greater than the porosity of the first intermediate zone but less than the porosity of the inner zone.

[0016] The second, intermediate zone may exhibit a porosity of 40-85% of the porosity of the inner zone.

[0017] The porous product surface may exhibit pores having a maximum cross-sectional width of 0.1 to 0.7 mm, preferably 0.25 to 0.6 mm.

[0018] The first intermediate zone may exhibit pores having an average maximum cross-sectional area that is smaller than the pores exhibited by the inner zone.

[0019] The second intermediate zone may exhibit pores having a larger average maximum cross-sectional area than the pores exhibited by the first intermediate zone.

[0020] The mould may have an edge portion extending around the periphery of the mould and presenting an angle of more than 60 degrees, preferably more than 75 degrees, or even 85-90 degrees, to the direction of relative movement of the mould.

[0021] The outer zone may be formed at the edge portion.

[0022] The outer zone may be bounded on the outside by a wall extending at an angle of less than 50 degrees, preferably less than 30 degrees, or between 0 and 10 degrees, to the direction of relative movement of the dies.

[0023] The outer zone may extend inwardly from an imaginary intersection between the wall and the edge portion a distance of less than 0.5 mm, preferably less than 0.3 mm.

[0024] Thus, there may be a soft transition between the wall and the edge portion of the mold.

[0025] An "imaginary intersection" is defined as the point where an imaginary line along the wall intersects with an imaginary line along the edge portion when viewed on a cutting plane perpendicular to the wall and the edge portion.

[0026] According to a second aspect of the present disclosure, there is provided a method of producing a 3D molded product from a pulp slurry, the method comprising the steps of applying a pulp slurry layer to a porous product surface of a first mold and, in a first forming step, heating the pulp slurry layer and pressing the pulp slurry layer against the porous product surface of the first mold while drawing a vacuum through the porous forming surface of the first mold, wherein the vacuum drawn through the porous product surface of the first mold is gradually reduced toward an outer product end surface defining an outermost limit of the forming area of ​​the tool, said reduction being achieved through a gradual decrease in porosity of the porous forming surface.

[0027] The first mould may form part of a mould set in accordance with what has been described above.

[0028] The method may further include transferring the pulp slurry layer to a porous forming surface of a second mold and, in a second subsequent forming step, heating the pulp slurry layer and pressing the pulp slurry layer against the porous mold of the second mold while drawing a vacuum through the porous forming surface of the second mold.

[0029] In the first forming step, the forming surface of the first mold can be heated to about 150-400°C, preferably 200-300°C.

[0030] In the first forming step, the pulp slurry layer can be pressed against the forming surface of the first die at a pressure of about 390 to 1570 kPa, preferably 580 to 1170 kPa.

[0031] In the first forming step, the pulp slurry layer can be pressed against the forming surface of the first die for a first pressing time of 0.1 to 4.0 seconds, preferably 0.5 to 2.0 seconds.

[0032] In the first forming 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.

[0033] The vacuum level behind the forming surface of the second mold may be from 50 to 99 kPa, preferably from 65 to 85 kPa.

[0034] The method may further include transferring the pulp slurry layer to a porous forming surface of a third die and, in a third subsequent forming step, heating the pulp slurry layer and pressing the pulp slurry layer against the porous forming surface of the third die while drawing a vacuum through the porous forming surface of the third die, wherein the vacuum level in the second forming step is higher than the vacuum level in the third forming step.

[0035] The third vacuum level on the back side of the forming surface of the third mold can be from 50 to 99 kPa, preferably from 65 to 85 kPa.

[0036] In the third forming step, the forming surface of the third mold can be heated to about 100-300°C, preferably 200-280°C.

[0037] In the third forming step, the pulp slurry layer can be pressed against the forming surface of the third die at a pressure of about 390 to 1570 kPa, preferably 580 to 1170 kPa.

[0038] In the third forming step, the pulp slurry layer can be pressed against the forming surface of the third die for a third pressing time of 0.1 to 4.0 seconds, preferably 0.5 to 2.0 seconds.

[0039] In the third forming step, the initial moisture content of the pulp slurry layer may be about 25-45% by weight or 25-40% by weight, preferably about 30-40% by weight 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.

[0040] The first die may be a pick-up die to which the pulp slurry is applied from a liquid state, said pulp slurry having a pulp concentration of less than 0.5% by weight, preferably less than 0.49%, or between 0.005 and 0.025%. [Brief description of the drawings]

[0041] [Figure 1a] FIG. [Figure 1b] FIG. [Figure 1c] FIG. [Diagram 2] FIG. 2 is a schematic diagram showing the manufacturing process. [Diagram 3] 1 is a schematic diagram showing the edge portions of a pair of molds 30, 40. FIG. [Figure 4] 1 is an enlarged schematic view of an edge portion of a female mold 40. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] 1a shows diagrammatically a pick-up tool 10 partially immersed in a container 1 holding a pulp slurry 2. The pick-up tool is mounted in a tool holder 11, which together with the pick-up tool defines a vacuum chamber 12 connected to a pressure regulator P1. The pressure regulator may have the capability of selectively generating at least a partial vacuum (i.e., an air pressure lower than ambient air pressure) and / or an air pressure higher than ambient air pressure.

[0043] While the pick-up tool is immersed in the pulp slurry 2 , a pressure regulator P 1 may create a vacuum to adhere the pulp fibers 3 to the product surface of the pick-up tool 10 .

[0044] 1b shows diagrammatically the pick-up tool 10 transferring the pulp fibres 3 to a transfer tool 20. The transfer tool may be connected to a second pressure regulator P2, which may generate a vacuum or air pressure. The transfer tool may also be mounted on a transfer tool holder 21 to define a vacuum chamber 22 connected to the second pressure regulator.

[0045] During the transfer of the pulp fibers 3 from the pick-up tool to the transfer tool, an air pressure higher than the ambient pressure can be generated by the first pressure regulator P1 to release the pulp fibers from the pick-up tool.

[0046] Alternatively, or as a complement, a vacuum may be created by a second pressure regulator P2 such that the pulp fibers are received by the transfer tool 20.

[0047] Figure 1c shows diagrammatically a press arrangement comprising a male press tool 30 and a female press tool 40. One or both of the press tools may be mounted in a respective tool holder 31, 41 and connected to a respective vacuum chamber 32, 42. The vacuum chambers may be connected to respective pressure regulators P3, P4.

[0048] One or both of the press tools may be provided with heating elements 33, 43, energized by energy sources E1, E2 and optionally controlled by a controller C. Heating may be achieved by hot air or liquid, or electric heating elements such as induction.

[0049] The press tools, and their associated tool holders, may be movable relative to one another between an open position in which a partially molded pulp product may be inserted, and a press position in which the press tools are forced towards one another, thus pressing the product 3'' between the product faces of the respective tools 30, 40.

[0050] When in the pressing position, heat may be provided by one or both of heaters 33, 43.

[0051] During the pressing step, one or both pressure regulators P3, P4 may provide a vacuum to assist in evacuating water vapor from the product 3''.

[0052] Alternatively, one of the pressure regulators may provide a vacuum and the other a pressure higher than ambient air pressure.

[0053] Optionally, hot air or steam may be introduced through the die during the pressing process (FIG. 1c).

[0054] It should be noted that two or more successive pressing steps may be used, for example to gradually form all or part of product 3'' and / or to apply additional features to the product, such as coatings, decorations, etc.

[0055] In one embodiment, steps are performed according to what was described with respect to Figures 1a, 1b, and 1c.

[0056] The manufacturing process will now be described with reference to FIG.

[0057] In a first step 101, a layer of pulp slurry is provided, for example as described with reference to FIG. 1a, and a porous pick-up tool may be submerged in the pulp slurry while applying a vacuum to the backside of the pick-up tool.

[0058] Alternatively, the pulp slurry may be applied to the pick-up tool by a coating operation, such as spray coating.

[0059] In a second step 102, the pulp slurry layer is transferred from the pick-up tool to the first press tool. The transfer can be performed by the pick-up tool or by a separate transfer tool, which can have a porous transfer tool wall portion. During the transfer step, a vacuum can be applied to the back side of the transfer tool wall so that the pulp slurry layer is held to the transfer tool wall. It is possible to apply pressurized air to the back side of the transfer tool wall instead to release the pulp slurry layer from the transfer tool wall.

[0060] Alternatively, the pulp slurry layer may be applied directly to the first press tool. That is, the pulp slurry layer may be formed directly on the first press tool by application of the pulp slurry to a porous forming surface of the first press tool. The pulp slurry layer may be applied directly to the first press tool by submerging a tool part of the first press tool exhibiting a porous wall portion in the pulp slurry while applying a vacuum to a back side of the porous wall portion. Alternatively, the pulp slurry may be applied to the porous forming surface of the first press tool by a coating operation, such as spray coating.

[0061] In a third step 103, the pulp slurry layer can be pressed in a first press tool, which may include a pair of mating tool parts, one of which may have a porous wall portion in contact with the pulp slurry layer and through which a vacuum can be drawn.

[0062] In this first pressing step 103, a pressure less than the surrounding ambient pressure is applied to the backside of the porous wall portion, thus creating a vacuum behind the porous wall portion and drawing solvent vapors, such as steam, through the tool.

[0063] The pressure applied to the back side of the porous wall portion may be a low or medium level vacuum, i.e. the pressure may be higher than 1 Pa but lower than ambient pressure. Preferably the pressure may be from 1 kPa to ambient pressure.

[0064] In the first pressing step, the first vacuum level behind the forming surface of the first mold may be about 50-99 kPa, typically 65-85 kPa.

[0065] In the first pressing step, the first pressure behind the forming surface of the first mold may be between 200 and 900 mbarA (millibar absolute), preferably between 300 and 800 mbarA.

[0066] The forming surface of the first die may be heated to about 150-500° C., preferably 150-400° C., 200-500° C., 200-400° C., or 200-300° C., and in most cases 240-280° C. Typically, all die surfaces that come into contact with the pulp slurry are heated.

[0067] The pressing pressure between the die faces can be about 390 to 1570 kPa, and in most cases about 580 to 1170 kPa.

[0068] The pressing pressure may be applied for a first pressing time of 0.1 to 4.0 seconds, preferably 0.5 to 2.0 seconds. In most settings, a pressing time of about 0.5 to 1.5 seconds is sufficient, and in many cases, 0.5 to 1.0 seconds may be sufficient.

[0069] Typically, in this first step, the initial moisture content of the pulp slurry layer is 70-90% by weight, and after the pressing step is performed, the final moisture content may be 45-65% by weight, typically about 50-60% by weight.

[0070] After the first pressing step 103, the pulp slurry layer, now having had a substantial amount of its solvent removed, may be transferred 104 to a second press tool. Transfer 104 may be performed in the same manner and with similar equipment as the first transfer step 102. The second press tool may be designed essentially as the first press tool.

[0071] In a second pressing step 105, the pulp slurry layer can be pressed in a second press tool, which may include a pair of mating tool parts, one of which may have a porous wall portion in contact with the pulp slurry layer and through which a vacuum can be drawn.

[0072] In this second pressing step 105, a pressure less than the surrounding ambient pressure is applied to the backside of the porous wall portion, thus creating a vacuum behind the porous wall portion and drawing solvent vapors, such as steam, through the tool.

[0073] In the second pressing step, the second vacuum level behind the forming surface of the second mold can be about 50-99 kPa, typically 65-85 kPa, but always a lower vacuum level than in the first pressing step.

[0074] In the second pressing step, the second pressure behind the forming surface of the second mold may be between 200 and 900 mbarA (millibar absolute), preferably between 300 and 800 mbarA.

[0075] The forming surface of the second mold can be heated to about 110 to 500° C., preferably 110 to 400° C., 150 to 500° C., 150 to 400° C., 200 to 500° C., 200 to 400° C., or 200 to 300° C., and in most cases 240 to 280° C. Typically, all mold surfaces constituting the second mold and in contact with the pulp slurry layer can be heated.

[0076] The pressing pressure between the die faces can be about 390 to 1570 kPa, and in most cases about 580 to 1170 kPa.

[0077] The pressing pressure may be applied for a second pressing time of 0.1 to 4.0 seconds, preferably 0.5 to 2.0 seconds. In most setups, a pressing time of about 0.5 to 1.5 seconds is sufficient, and in many cases, 0.5 to 1.0 seconds may be sufficient.

[0078] 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.

[0079] The final moisture content may be about 25-40% by weight, preferably about 30-35% by weight.

[0080] After the second press step 105, the pulp slurry layer, now having had a substantial amount of its solvent removed, may be transferred 106 to a third press tool. Transfer 106 may be performed in the same manner and with similar equipment as the first transfer step 102 and / or the second transfer step 104. The third press tool may be designed essentially as the first press tool.

[0081] In a third press step 107, the pulp slurry layer can be pressed in a third press tool, which may include a pair of mating tool parts, one of which may have a porous wall portion in contact with the pulp slurry layer and through which a vacuum can be drawn.

[0082] In this third pressing step 107, a pressure less than the surrounding ambient pressure is applied to the backside of the porous wall portion, thus creating a vacuum behind the porous wall portion and drawing solvent vapors, such as steam, through the tool.

[0083] In the third press step, the third vacuum level behind the forming surface of the third mold can be about 50-99 kPa, typically 65-85 kPa, but always a lower vacuum level than in the second press step.

[0084] In the third pressing step, the third pressure behind the forming surface of the third mold may be between 200 and 900 mbarA (millibar absolute), preferably between 300 and 800 mbarA.

[0085] The forming surface of the third die can be heated to about 100 to 400° C., preferably 100 to 300° C., 150 to 400° C., 150 to 300° C., 200 to 300° C., or 200 to 280° C., and in most cases 240 to 280° C. Typically, all die surfaces constituting the third die and in contact with the pulp slurry layer can be heated.

[0086] The pressing pressure between the die faces can be about 390 to 1570 kPa, and in most cases about 580 to 1170 kPa.

[0087] The pressing pressure may be applied for a third pressing time of 0.1 to 4.0 seconds, preferably 0.5 to 2.0 seconds. In most settings, a pressing time of about 0.5 to 1.5 seconds is sufficient, and in many cases, 0.5 to 1.0 seconds may be sufficient.

[0088] Typically, in this third pressing step, the initial moisture content of the pulp slurry layer can be about 25-45% by weight or 25-40% by weight, preferably about 30-40% by weight or 30-35% by weight, and the final moisture content can be less than about 5% by weight, preferably less than about 1% by weight.

[0089] After the third pressing step 107, the pulp slurry layer, now with most of its solvent removed, may be transported 108 out of the machine.

[0090] Optionally, additional steps may be performed on the thus essentially dried product, such as surface treatment, cutting, or printing, etc. The product may then be packaged, stored, and shipped.

[0091] It should be noted that the third press step 107, and thus its associated transfer step 106, are also optional. Thus, the process may end after the second press step 105, immediately followed by the output step 108.

[0092] Thus, 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.

[0093] In the second pressing step, the initial moisture content of the pulp slurry layer may be about 25-50% by weight, preferably about 30-35% by weight, and the final moisture content may be less than about 5% by weight, preferably less than about 1% by weight.

[0094] 3 and 4, an edge portion of a tool set is shown.

[0095] 3 shows male and female molds 30, 40 having respective out-of-plane portions 301, 401 and respective edge portions 302, 402 surrounding the respective out-of-plane portions 301, 401. The edge portions may, but do not necessarily, also include respective outer edge walls 303, 403 formed on the outermost portions of the edges 302, 402.

[0096] The edge 302, 402 may be substantially planar and may surround the out-of-plane portion 301, 401.

[0097] The edge portions may be substantially planar and extend substantially perpendicular to the direction of relative movement of the dies during the final part of the pressing operation, while the edge walls 303, 403 may extend substantially perpendicular to the edge portions 302, 402.

[0098] In practice, the edge portions 302, 402 may extend at an angle of 60-90 degrees, preferably 75-90 degrees, 85-90 degrees, or 89-90 degrees to the direction of movement.

[0099] Similarly, the wall portions 303, 403 may extend at an angle of 0 to 60 degrees relative to the direction of movement, preferably 0 to 45 degrees, 0 to 30 degrees, 0 to 15 degrees, 0 to 5 degrees, or 0 to 1 degree.

[0100] The edge portion may extend from an imaginary intersection between a surface of the wall portion 303, 403 and a surface of the edge portion 302, 402. Thus, for each mold, there may be a soft transition between the wall 303, 403 and the edge portion 302, 402, respectively, and the "imaginary intersection" is the point where an imaginary line along the wall intersects with an imaginary line along the edge portion when viewed on a cutting plane perpendicular to the wall and the edge portion.

[0101] The edge portions may range from 1 to 15 mm in total, with each zone extending over less than 1 mm, preferably less than 0.5 mm, or less than 0.3 mm.

[0102] As mentioned above, one or both of the molds 30, 40 may have a porous forming surface. In the illustrated example, the female mold 40 is shown as having a porous forming surface, however, it may also or alternatively be the male mold 30 that has a porous forming surface.

[0103] The central portion of the mold 30, 40 may have a predetermined nominal porosity, which may be constant or may vary across the central portion.

[0104] The central portion may be anything inside the edge portion or may be any transition from the edge portion to the wall.

[0105] The edge portion 402 may have a gradually decreasing porosity, resulting in zero porosity at the outermost portion of the edge portion 402 .

[0106] In the illustrated example, the edge portion 402 is divided into three zones: a first zone Z1 having zero or very low porosity, a second zone Z2 having a higher porosity, a third zone Z3, optionally having an even higher porosity than the second zone Z2, and then an inner zone Z4 having a nominal porosity.

Claims

1. 1. A tool for producing a 3D shaped product from a pulp slurry, comprising: a pair of dies having respective product surfaces facing each other and configured to press the pulp layer therebetween; the product surface provides a 3D shape for forming the 3D molded product; the product surfaces define respective outer product edge surfaces and define outermost limits of forming regions of at least one of the molds; At least one of the product faces, looking inwardly from the product end face toward a center of gravity of the product face, an outer zone (Z1) that is substantially free of porosity; an inner zone (Z4) having a porosity of 40-75%; Presenting, a first intermediate zone (Z2) disposed between said outer zone (Z1) and said inner zone (Z4) and having a porosity higher than that of said outer zone (Z1) and lower than that of said inner zone (Z4).

2. The tool according to claim 1, wherein said outer zone (Z1) exhibits a porosity of less than 1%, preferably less than 0.5% or less than 0.1%.

3. Tool according to claim 1 or 2, wherein the first intermediate zone (Z2) exhibits a porosity between 25 and 75% of the porosity of the inner zone.

4. 4. The tool according to claim 1, wherein the product face presents a second intermediate zone (Z3) having a porosity higher than that of the first intermediate zone but lower than that of the inner zone.

5. The tool according to claim 4, wherein said second intermediate zone (Z3) exhibits a porosity between 40 and 85% of the porosity of said inner zone.

6. A tool according to any one of claims 1 to 5, wherein the porous product surface presents pores having a maximum cross-sectional width of 0.1 to 0.7 mm, preferably 0.25 to 0.6 mm.

7. 7. The tool according to claim 6, wherein the first intermediate zone (Z2) presents pores having an average maximum cross-sectional area smaller than the pores presented by the inner zone (Z4).

8. 8. The tool according to claim 7, wherein said second intermediate zone (Z3) presents pores having a larger average maximum cross-sectional area than the pores presented by said first intermediate zone (Z2).

9. A tool according to any one of claims 1 to 8, wherein the mould comprises an edge portion (302, 402) extending around the periphery of the mould and presenting an angle of more than 60 degrees, preferably more than 75 degrees, or between 85 and 90 degrees, with respect to the direction of relative movement of the mould.

10. The tool according to claim 9, wherein the outer zone (Z1) is formed in the edge portion (302, 402).

11. Tool according to claim 9 or 10, wherein the outer zone (Z1) is bounded on the outside by a wall (303, 403) extending at an angle of less than 50 degrees, preferably less than 30 degrees, or between 0 and 10 degrees, relative to the direction of relative movement of the dies.

12. Tool according to any one of claims 9 to 11, wherein the outer zone (Z1) extends inwards from an imaginary intersection between the wall (303, 403) and the edge portion (302, 402) a distance less than 0.5 mm, preferably less than 0.3 mm.

13. 1. A method for producing a 3D shaped product from a pulp slurry, comprising: applying a layer of pulp slurry to a porous product surface of a first mold; a first forming step of heating the pulp slurry layer and pressing the pulp slurry layer against the porous product surface of the first die while drawing a vacuum through the porous product surface of the first die; Equipped with the vacuum drawn through the porous product surface of the first mold is gradually reduced toward an outer product end surface defining an outermost limit of a forming area of ​​the tool; The method wherein said reduction is accomplished through a gradual decrease in porosity of said porous product surface.

14. transferring the layer of pulp slurry to a porous forming surface of a second mold; in a second subsequent forming step, heating the pulp slurry layer and pressing the pulp slurry layer against the porous forming surface of the second die while drawing a vacuum through the porous forming surface of the second die; The method of claim 13 further comprising:

15. The method according to claim 13 or 14, wherein in the first forming step, the forming surface of the first mould is heated to about 150-400°C, preferably 200-300°C.

16. The method of any one of claims 13 to 15, wherein in the first forming step, the pulp slurry layer is pressed against the forming surface of the first die at a pressure of about 390 to 1570 kPa, preferably 580 to 1170 kPa.

17. 17. The method according to any one of claims 13 to 16, wherein in the first forming step, the pulp slurry layer is pressed against the forming surface of the first die for a first pressing time of 0.1 to 4.0 seconds, preferably 0.5 to 2.0 seconds.

18. 18. The method according to any one of claims 13 to 17, wherein in the first forming step, the initial moisture content of the pulp slurry layer is 70-90% by weight and the final moisture content is 45-65% by weight, preferably about 50-60% by weight.

19. A method according to any one of claims 14 to 18, wherein the vacuum level behind the forming surface of the second mould is between 50 and 99 kPa, preferably between 65 and 85 kPa.

20. 20. The method of any one of claims 14 to 19, further comprising the steps of transferring the pulp slurry layer to a porous forming surface of a third die, and in a third subsequent forming step, heating the pulp slurry layer and pressing the pulp slurry layer against the porous forming surface of the third die while pulling a vacuum through the porous forming surface of the third die, wherein a vacuum level in the second forming step is higher than a vacuum level in the third forming step.

21. The method of claim 20, wherein a third vacuum level behind the forming surface of the third mould is between 50 and 99 kPa, preferably between 65 and 85 kPa.

22. The method of claim 20 or 21, wherein in the third forming step, the forming surface of the third mould is heated to about 100-300°C, preferably 200-280°C.

23. 23. The method of any one of claims 20 to 22, wherein in the third forming step, the pulp slurry layer is pressed against the forming surface of the third die at a pressure of about 390 to 1570 kPa, preferably 580 to 1170 kPa.

24. 24. The method according to any one of claims 20 to 23, wherein in the third forming step, the pulp slurry layer is pressed against the forming surface of the third die for a third pressing time of 0.1 to 4.0 seconds, preferably 0.5 to 2.0 seconds.

25. 25. The method according to any one of claims 20 to 24, wherein in the third forming step, the initial moisture content of the pulp slurry layer is about 25-45% by weight or 25-40% by weight, preferably about 30-40% by weight or 30-35% by weight, and the final moisture content is less than about 5% by weight, preferably less than about 1% by weight.

26. 26. The method according to any one of claims 20 to 25, wherein the first die is a pick-up die to which a pulp slurry is applied from a liquid state, the pulp slurry having a pulp consistency of less than 0.5% by weight, preferably less than 0.49%, or between 0.005 and 0.025%.

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