METHOD OF MOLDING BY PRESSING A PRESS-MOLDED FIBER PRODUCT, AND, PRESS-MOLDED FIBER PRODUCT

Description

/ 9 METHOD OF MOLDING BY PRESSING A PRESS-MOLDED FIBER PRODUCT, AND, PRESS-MOLDED FIBER PRODUCT TECHNICAL AREA

[001] This invention relates to a method of press molding a fiber product, at high pressure and high temperature, from a blank sheet consisting of an integrated fiber network, by means of a press pad device and a stamping device, to perform the method. TECHNICAL TRAINING

[002] A fiber product can be made by pressing different types of raw materials, for example, wood flakes, as known in US 4,248,820 and WO 2009132318. However, this invention relates to a different field, in which a continuous sheet or a fiber sheet consisting of an integrated fiber network is used. Typically, a combination of natural fibers (e.g., wood pulp fibers), synthetic fibers (e.g., polyolefin-based fibers, such as those made from polyethylene), and other additives, such as binder or colorant, is used. In many applications, it is preferable that such a continuous sheet be composed essentially of natural fibers, with or without additives. Typical process conditions are 150-250°C and pressures of 10000000 - 1000000000 Pa (100-10000 bar) (20000000-2000000000 Pa (200-2000 bar)). The moisture content can normally be less than 20%, as described, for example, in WO 2018013397 and US 4 227 710.

[003] The fiber product may be in the form of a hollow product, for example, a package or a closure (lid, screw cap or similar), but it may also be a flat product. The products may be formed from a continuous sheet of the material and perforated / cut during forming, for example, which were completely or partially Petition 870250088686, dated 09 / 30 / 2025, page 10 / 25 / 9 separated from the continuous sheet to allow for deeper modeling. This exposure is usually done by cutting the material into a shape that suits the final form. Typically, for example, a medallion is cut to form a round package.

[004] Press molding typically occurs with two tools, where both the outer pad and the inner tool (stamp) may consist of multiple parts to allow discharge of the finished product. Typically, the pad opens while the stamp retracts. The piston, parts of the piston, or parts of the pad may also be made of a compressible material that allows greater vertical compression forces, typically against the sides of the cavity, by the tool material being reshaped during compression.

[005] Other examples of known methods described above are shown in EP 3 736 099 and WO 2020 / 165780. SUMMARY OF THE INVENTION

[006] One objective of the invention is to optimize, from a strength perspective, certain applications related to press-molded fiber products, as defined in the independent claims.

[007] Thanks to the invention, reinforced press-molded fiber products can be obtained with low raw material requirements and in an economical manner. A specific advantage is that, in contrast to folded reinforcement parts of a fiber product, the invention will produce reinforcement parts in which the fiber network is favorably integrated, thanks to the principle of using a pushing action to form the reinforcement parts, i.e., providing an optimized fiber network before and / or during pressing. DESCRIPTION OF THE FIGURES

[008] The invention will now be described with reference to a Petition 870250088686, dated 09 / 30 / 2025, page 11 / 25 / 9 preferred embodiment of flat-shaped press-molded fiber products, in which: Figure 1 shows a perspective view of a press-molded fiber product for use as a bottle holder, according to the invention.

[009] - Figure 2 shows a cross-sectional view along AA in Figure 1.

[0010] - Figure 3 shows a top view of a press-molded lid according to the invention. Figure 4 shows a cross-sectional view along BV in Figure 3. Figure 5 shows a top view of a preferred pre-cut raw material intended for the production of a lid as shown in Figures 3 and 4, according to the invention, and Figure 6 schematically shows a cross-sectional view of a mold for producing a lid as shown in Figures 3 and 4, according to the invention. DETAILED DESCRIPTION

[0011] As understood by the skilled technician, the invention is based on the use of a fiber press mold (not shown), comprising a pressing pad device and a stamping device, to form a fiber product according to the invention. The stamping device may be solid in a single piece or divisible into two or more pieces. Said device may also be foldable. The pressing pad device comprises a body arranged with at least one cavity, the body of which may be solid or divisible into two or more pieces. The stamping member comprises a body adapted to fit into the cavity so that a gap may be formed between the side surface and the side walls of the cavity, through which a Petition 870250088686, dated 09 / 30 / 2025, page 12 / 25 / 9 The desired thickness of side walls can be achieved and subsequently molded in such a way as to also obtain flat and / or curved parts of a desired thickness of a fiber product, by pressing at a distance that achieves the desired thickness.

[0012] The material in fiber product 1 comprises natural fibers, such as natural wood fibers, straw, such as bagasse, and / or recycled wood fibers or a combination thereof, preferably natural wood fibers, virgin natural wood fibers are more preferred or, where sustainability is important, recycled wood fibers may be preferred. Preferably, the raw material is a sheet with a uniformly distributed amount of fibers in each part of its cross-section and also a basically constant thickness, so that all parts have substantially the same density, wherein the raw pieces are cut from said sheet for pressing in the subsequent step. The amount of water in a pre-cut raw piece (e.g., medallion) before pressing should preferably not exceed 20% of the fiber weight.The molding temperature can be in the range of 150-250 °C and the pressure applied by stamp 3 and additional stamping device 4 is at least 20000000 Pa (200 bar). The pressure can be further increased so that it is between approximately 50000000 Pa (500 bar) and approximately 100000000 Pa (1000 bar).

[0013] Figure 1 shows an exemplary embodiment of a product manufactured according to the invention. A bottle holder 1 is shown having a plurality of passages 35 forming support members H for holding bottle necks and two holes 4 for carrying the bottle holder 1. The bottle holder has a support part 2 made of cellulose fibers according to the dry forming process described above. The bottle holder 1 comprises reinforcing members 3 that assist in providing enhanced strength properties in areas Petition 870250088686, dated 09 / 30 / 2025, page 13 / 25 / 9 selected. The selected areas can be positioned in various positions depending on the product. The basic principle for obtaining these reinforcing members lies in providing more fibers in the areas that form the reinforcing members 3. This can be achieved by relocating raw material fibers and transferring fibers to selected desired areas.

[0014] Thus, in the exemplary embodiment shown, this can be achieved by moving the fiber material away from the areas that, in a final product, will form passages 35, 4, moving these fibers transversely within the fiber layer, which will result in a greater quantity of fibers in the transverse direction in these desired areas, forming the reinforcing members 3.This can be achieved, for example, by means of protruding and penetrating parts according to the shape that the passage should have in a final product, for example, circular for the holes 4 and a portion of a circle for the bottle supports H. As a result, the reinforcing members 3 can be made to have a reinforcing body 30 thicker than the body 20 of the supporting part 2, obtaining outer edges 32 as transition zones and possibly more rounded inner edges 31. Preferably, the semi-closed passages 35 will be arranged with compressed peripheral edges 34, which can provide extra strength and / or wear capacity.

[0015] Figure 2 shows a cross-sectional view along line AA in Figure 1, and therefore it is shown that the support body 20 will have a thickness t1 that is less than the thickness t2 within the reinforcing body 30 of the reinforcing members 3. As can be observed, the width W of the reinforcing body 30 will then be limited. The width W can be used to control the density as well as the thickness t2 of the reinforcing body 30. In the embodiment shown, all the fibers that are present in the area of ​​the passages H, 4 of the blank before pressing, for the bottle holder 1, will be pushed into neighboring areas and integrated there to form members of Petition 870250088686, dated 09 / 30 / 2025, page 14 / 25 / 9 reinforcement 3 with a reinforcement body 30 with more fibers and greater thickness t2. As a result of the fibers being pushed out of the passages, greater strength will be achieved in the reinforced areas 3. By controlling the size of the press members (not shown), the thickness t2 and also the width W of the reinforcement members 3 can be controlled. Therefore, if a smaller thickness t2 is chosen, the density will increase even further. Consequently, even if the density within the support body 20 and the reinforcement body 30 of the reinforcement members 3 have the same density or not, the strength will be greater in the reinforcement members 3 thanks to the greater quantity of fibers.The actual amount of fibers can be determined using microscopic images and (computer-assisted) cross-sectional analysis of a product, where the amount of fibers within a certain distance from the cut surface, for example, the entire width W of the reinforcing members 30, is compared with the amount of fibers within the same cut surface at an equal distance (i.e., W) from the neighboring body 20. As is evident, the same functionality will also be achieved in connection with the holes 4 for carrying the bottle holder 1. Thus, reinforcing members 3 will be obtained around the holes 4, which will increase the strength and may also provide greater comfort for carrying the bottle holder 1. In a more preferred embodiment, the reinforcing members 3 have curved parts, for example, being semicircular or circular.

[0016] Figures 3 and 4 show an alternative exemplary embodiment according to the invention. Here it is shown in the form of a lid 5 for use on a cup. The lid 5 has a passage 6 adapted for drinking and a hole 7 to allow air to enter the cup during ingestion. In a known manner, the lid 5 is arranged with a U-shaped collar 50 that can be used to fit onto the upper edge of a cup.

[0017] Figure 4 shows a cross-sectional view of the Petition 870250088686, dated 09 / 30 / 2025, page 15 / 25 / 9 cover 5 along lines BB. It can be noted that the cross-sectional line passes through a plurality of reinforcing members 3. There are reinforcing members 3 within an outer collar part 50, whose reinforcing bodies 33 have the same thickness as the other parts of the cover, but have a greater quantity of compressed fibers in that volume. Therefore, this body part 33 has a higher density than most of the body parts of the support part 2 of the cover. Similarly, it is shown that there is a compressed body part 34 of higher density disposed around the cut hole 7 and also a corresponding compressed body part 35 around the beverage passage 6.

[0018] Figure 5 shows a preferred type of pre-cut piece 8 that can be used to produce caps 5 according to that shown in Figures 3 and 4. As can be seen, the shape of the present blank 8 is polygonal, preferably hexagonal, which is preferably cut from a wide sheet of raw material, providing space for a plurality of initial pre-cut blanks 8,8' in a neighboring manner, without any spillage. Preferably, the raw material for the pre-cut piece 8 is a sheet with a uniformly distributed amount of fibers in each part of the cross-section and also a basically constant thickness, so that all parts have substantially the same density. Also shown with markings 51 is the part that will form the lower edge 51 of the cap in the final products, as well as a circle 50 marking the part where the outer upper part of the cap collar 50 will be molded.Furthermore, indications are shown marking where the beverage passage 6 and the air hole 7 will be positioned in the final product.

[0019] Figure 6 schematically shows an exemplary female part of a mold that can be used to produce the cap 5 according to the invention. As can be seen, the shape is arranged with a first protruding part 94 adapted to the desired shape of the beverage passage 6. Petition 870250088686, dated 09 / 30 / 2025, p. 16 / 25 / 9 (e.g., oval) and also a second protruding part 33 adapted to the shape (e.g., circular) of the air hole 7. Furthermore, it can be noted that the outer periphery 92 of the mold has a diameter that corresponds to the circular line 50 of the pre-cut raw material 8.

[0020] When producing the lid 5, as shown in Figure 5, a pre-cut piece 8 will be cut from the largest sheet of raw material, for example, a plurality of hexagonal pieces, each being used to produce a lid 5. It is understood that, thanks to the use of the hexagonal shape, the yield of the basic sheet can be much greater than if circular raw materials were used, since they can be stamped without any intermediate waste, as indicated by the display of the plurality of neighboring raw materials 8'. It is evident that the same principle can be used for rectangular pre-cut raw materials.

[0021] Once the sheet raw material 8 has been cut, it will be moved down into the mold 9, and thus the protruding parts 94, 93 will penetrate the raw material and push the fibers transversely into the neighboring areas. When moved further down, the edge portions 81, 82 of the raw piece 8 will be folded upwards and positioned along the inner wall 92 of the mold 9. And now, when the stamp is pressed from top to bottom into the mold 9, the upper edge parts 82 will first be pushed / pressed into the lower part 81 of the collar area, and thus the corner portions 82 of the raw piece 8 will be pushed into the cylindrically formed lower part 81 of the raw material and will be integrated into the part that will form the outer wall of the collar 50. As a consequence, there will be a greater quantity of fibers within the parts that integrated the corner portions 82, to form the reinforcing members 3.Similarly, the fibers that have been pushed away by the protruding parts 94, 93 will provide reinforcing members 3 with more fibers around these passages 6, 7. By using a stamp (not shown) that provides thickness. Petition 870250088686, dated 09 / 30 / 2025, page 17 / 25 / 9 unified of the lid, as shown in Figure 4, the density of the reinforcing members 3 will be greater than the rest of the support body 2 of the lid 5, that is, having greater resistance thanks to the greater density.

[0022] As understood, the reinforcing members 3 can be obtained in different ways. However, transversely there will always be a greater quantity of fibers in the reinforcing members than in the main part of the supporting body 20.

[0023] It is evident to the specialist that combinations of the exemplary modalities mentioned above can be used and that, by using and adjusting the mold measurements, different properties can be achieved to adapt the reinforcing member 3 to the desired property within different parts within the same product. However, always having the member integrated with the other. Petition 870250088686, dated 09 / 30 / 2025, page 18 / 25

Claims

1 / 3 CLAIMS 1. A press molding method for a press-molded fiber product, under high pressure and high temperature, by means of a press pad device (9) and a stamping device, said press pad device (9) including an open space (91) having a bottom part (94) and a wall part (92), said stamping device having a coupling shape that provides a product clearance relative to said press pad device (9), wherein said fiber product (1, 5) is produced from a blank sheet (8) consisting of an integrated fiber network that is cut from a raw material sheet consisting of an integrated fiber network and formed in said clearance and by means of which said blank (8) after press molding will be molded into said fiber product (1, 5),characterized in that it provides said blank (8) with at least one excess portion (82) and that said at least one excess portion (82) before pressing or in connection with pressing is pushed into a neighboring portion of said blank (8) to be integrated into at least one reinforcing portion (3) of said fiber product (1, 5).

2. Press molding method according to claim 1, characterized in that after pressing said reinforcing portion (3) is integrated into a support body (20) having a thickness (t1) that is less than the thickness (t2) of a reinforcing body (30) of the reinforcing members (3).

3. Press molding method according to claim 1 or 2, characterized in that said at least one excess portion (82) before pressing is pushed into a neighboring portion of said blank (8) by means of at least one protruding device (93, 94) arranged within said press pad device (9), thus forming at least one passage (6, 7) having a reinforcing body (30, 34, 35) on the edge of said passage (6, 7).

4. Press molding method according to claim 1, characterized in that said at least one excess portion (82) in connection with the pressing is pushed into a neighboring portion of said blank (8) by means of pushing a corner part (82) of a polygonal blank (8) into an edge zone (81) of said fiber product (5).

5. Press molding method according to claim 1, characterized in that the material comprises natural fibers, such as natural wood fibers, straw, such as bagasse, and / or recycled fiber or a combination thereof.

6. Press molding method according to claim 1, characterized in that the molding temperature is 150-250 °C and the pressure on said bottom part (11) is at least 20000000 Pa (200 bar).

7. Press molding method according to claim 1, characterized in that the amount of water in said blank (8) of sheet does not exceed the amount of fiber, wherein preferably the weight of water in the material does not exceed 20% of the weight of the fiber.

8. Press molding method according to claim 1, characterized in that said pre-cut blank (8) is cut from a sheet with a uniformly distributed amount of fibers in each part of the cross-section to be used and also a basically constant thickness, so that all parts to be used have substantially the same density.

9. Press-molded fiber product, obtained from a network of fibers integrated by the method as defined in any of the preceding claims, characterized in that it comprises a support body (20) and at least one reinforcing member (3) integrated with said support body (20), said reinforcing member (3) having a reinforcing body (30) that includes more fibers than the body (20) of the support body (2), said press-molded fiber product (5) comprising a passage (4, 6, 7, 35) closed by said reinforcing member (3).

10. Press-molded fiber product according to claim 9, characterized in that said reinforcing body (30) forms a semi-closed passage (35) providing an edge arranged to support an object.

11. Press-molded fiber product according to claim 9 or 10, characterized in that the thickness (t2) of said reinforcing body (30) is greater than the thickness (t1) of said body (20).

12. Press-molded fiber product for supporting objects according to claim 11, characterized in that said thicknesses are in the range of 1.1t1 < t2 < 3t1.

13. Press-molded fiber product for supporting objects according to any one of claims 9 to 12, characterized in that the width (L) of said reinforcing body (30) is greater than the thickness (t2) of said reinforcing body (30).

14. Press-molded fiber product for supporting objects according to claim 13, characterized in that the width range (W) of said reinforcing body (30) is 1.1t2 < W < 3t2. Petition 870250088686, dated 09 / 30 / 2025, page 21 / 25

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