Method for press-molding a cup-shaped textile product, a mold for pressing a textile product, and a cup-shaped textile product

Abstract

The present invention relates to a method for pressing a textile product by means of a press pad device (2) and a stamp device (3, 4) at high pressure and temperature, the textile product (1) comprising a bottom (11), a side wall (12) and an edge (10). The stamp device (3, 4) comprises two stamp members (3, 4), the first stamp member (3) forming at least the bottom (11) and the second stamp member (4) forming the edge (10). The present invention further relates to a textile pressing mould (2, 3, 4) and to the textile product (1).

Description

[Technical field]

[0001] The present invention relates to a method for pressing a cup-shaped textile product with a bottom, a side wall and a rim by means of a press pad device and a stamp device at high pressure and temperature, as well as a textile pressing mould for carrying out the method. [Background technology]

[0002] Cup-shaped textile products can be made by pressing woven fabrics or textile sheets. Typically, they are a combination of natural fibers (e.g., wood pulp fibers), synthetic fibers (e.g., polyolefin-based fibers), and other additives such as binders or dyes. In many applications, it is preferred that such textiles consist essentially of natural fibers, with or without additives. Typical processing conditions are temperatures of 150-250°C and pressures of 100-10,000 bar (200-2,000 bar). The moisture content is typically less than 20%.

[0003] The textile product may be a hollow product, for example a packaging or closure (a lid, a screw cap, etc.), but may also be a flat product. The product is formed from a woven web of material and may be punched / cut to allow for deeper shaping, for example with the formation of something that is fully or partially separated from the woven web. This exposed surface is typically achieved by cutting the material into a shape that will fit the final shape, for example typically cut into circles to form circular packages.

[0004] Generally, pressing is performed with two tools, both the outer tool pad and the inner tool (stamp), which can consist of several parts and allow the final product to be ejected. Generally, the pad is open while the stamp moves downwards. The piston, part of the piston or part of the pad can also be made of a compressible material, which allows a larger vertical compression force, generally against the sides of the cavity, due to the tool material being reshaped during compression.

[0005] When the product is formed, the upper edge is generally uneven, since the material is pressed into the tool. The uneven material can be cut off horizontally or vertically after or during forming. In both cases, a cut residue is formed, which must be treated in the production and ideally regenerated. If the cutting is performed in the same movement as the pressing, the design of the upper part of the tool is limited in that the edges of the two parts must be adapted to the cutting process. This can cause problems when feeding the material into the pad. Performing the cutting in the same movement as the pressing also creates the problem of pressing the material with a fairly large force at the same time as cutting it. This can cause the cut edge to consist of poorly shaped material. Examples of the known methods mentioned above are shown in EP 3736099 and WO 2020 / 165780.

[0006] CN 20132641774 discloses a production mould for producing a plate-shaped pulp product with a smooth outer edge, which comprises a convex press pad device, a central concave stamp device and an annular outer stamp device, which is used to form the smooth outer edge. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] European Patent No. 3736099 [Patent Document 2] International Publication No. 2020 / 165780 [Patent Document 3] China Patent Application Publication No. 20132641774 Summary of the Invention [Problem to be solved by the invention]

[0008] It is an object of the present invention to eliminate or at least minimize the above mentioned drawbacks, which is achieved by a method as defined in claim 1 and / or a mould for a textile press as defined in claim 13 and / or a textile product as defined in claim 14. [Means for solving the problem]

[0009] With the present invention, cutting the cup-shaped product after pressing can be completely avoided. In addition to removing the need for further cutting and eliminating the need to process the residue, the present invention can also result in a better product in that it can somewhat adjust the edge quality of the product, for example providing higher quality at the edges.

[0010] The invention will be explained below with reference to preferred embodiments of the general pressing mould and method according to the invention by outlining specific preferred examples of manufacture. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a schematic cross-sectional view of a pressing mould in the first stage of producing a cup-shaped cylindrical fibrous product. [Diagram 2] FIG. 2 is a schematic cross-sectional view of a pressing mould in a second stage of producing a cup-shaped cylindrical fibrous product. [Diagram 3] FIG. 3 is the same schematic cross-sectional view as FIG. 2, but with the pressing mould positioned with grooves for a striated cup-shaped cylindrical textile product. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In figures 1 and 2 a textile pressing mould is shown with a press pad device 2 and a stamp device for forming a textile product 1. The stamp device comprises two stamp members 3, 4, the first stamp member 3 being arranged to form at least the bottom 11 of the textile product 1 and the second stamp member 4 being arranged to form the edge 11 of the textile product. In the embodiment shown the second stamp member 4 is movable along the outer edge of the first stamp member 3.

[0013] The press pad device 2 comprises a body 20 having a total height H2. The press pad device 2 is arranged with a cavity 22, which in this embodiment is relatively large, for example to achieve a cup-shaped textile 1 with a vertical side wall 12 between the edge 10 and the bottom 11. The cavity 22 thus comprises a bottom surface 23 and a vertical side wall 24, which in this embodiment is formed by a ring-shaped cylindrical surface. The total height H22 of the cavity 22, from the horizontally extending bottom surface 23 of the cavity to the top surface 21 of the body 20, is arranged to be greater than the height H12 of the textile 1. Preferably, H2 is at least 10% greater than H12, preferably at least 15% greater.

[0014] The first stamp member 3 comprises a body 30 adapted to fit into the cavity 22 such that a gap can be formed between the vertical side surface 34 of the first stamp member 3 and the vertical side wall 24 of the cavity 22, whereby a desired thickness t12 of the side wall 12 of the textile product 1 can be achieved. This is achieved by having a cross-sectional width D2 of the cavity 22 that is twice as large as t12 as the cross-sectional width D3 of the first stamp member 3. It is clear to a person skilled in the art that the definition of "vertical" must be understood as substantially vertical, i.e. including shapes in which the side wall 12 (one or both of the side wall faces) may deviate somewhat from an exact 90° angle with respect to the horizontal plane of the bottom 11.

[0015] In the embodiment shown, where a circular product 1 is produced, this is achieved by using a circular shape of the side walls 24, 34, which form the cross-sectional width of the diameters D2 and D3, respectively. As will be appreciated by those skilled in the art, other shapes than a precise circular shape, for example simply along the side walls 24 of the press pad device 2, can of course be used. The second stamp member 4 has a ring-shaped body 40, which is arranged to slide along the outer surface 34 of the first stamp member 3, and which may have a height H4 that is lower than the height H3 of the first stamp member 3. An end surface 41 of the ring-shaped body 40 will form the edge 10 of the textile product 1.

[0016] When using the mold for press-molding the textile product 1, a pre-cut material (not shown) is introduced into the cavity 22 of the press pad device 2. The height H22 of the cavity 22 is the height at which the entire pre-cut material can be located in the cavity 22, i.e. at which no part of the pre-cut material protrudes above the upper surface 21 of the press pad device 2. In a first stage, the first stamp member 3 is subjected to a force F1 to move downwards into the cavity 22, at which time it presses the pre-cut material into the cavity 22 to form an intermediate product 1A with an uneven upper edge 10A. See FIG. 1. The height H22 of the cavity 22 is the height at which all parts of the uneven upper edge 10A are located below the upper surface 21 of the press pad device 2.

[0017] The second stamp member 4 is then subjected to a force F2 such that it moves along the outer surface 34 of the first stamp member 3 and is pressed down into the cavity 22 in the gap formed between the outer surface 34 of the first stamp member 3 and the wall 24 of the cavity. During formation, high temperatures are applied and high pressures are applied by the press pad device 2 and the stamp devices 3, 4 to form the textile product 1. The forming temperature is in the range of 150-250°C and the pressure applied by the stamps 3, 4 is at least 200 bar. In some applications it is preferred to apply a force F2 which results in a pressure P3 in the edge 10 of the product that is greater than the pressure P2 generated by the force F1 applied to the first stamp member 3.

[0018] As shown, the first stamp member 3 forms at least the bottom 11 of the textile 1 and the second stamp member 4 forms the edge 10. This basic principle can also be utilized for flat shaped textiles. Preferably, the first stamp member 3 forms at least a portion of the bottom 11 before the second stamp member 4 starts to form the edge 10.

[0019] Preferably, the first stamp member 3 is arranged (e.g. controlled by a sensor) to stop pressing at a given distance H3B relative to the position H0 of the press pad device 2, and the second stamp member 4 is arranged to stop pressing at a given position H4B relative to the position H0 of the press pad device 2. Of course, this latter position can also be set for the first stamp member 3. Most preferably, the end position of the first stamp member 3 is the position where the pressing stops at a given position H4B relative to the position H0 of the press pad device 2, thereby realizing a given thickness t11 of the bottom 11.

[0020] As shown in the figures, the textile product 1 may have a substantially vertical sidewall 12. The second stamp member 4 stops at a given distance H4B, a set distance H12 from the bottom 11, whereby the edge 10 is positioned such that the desired height H12 of the product 1 is achieved. As already mentioned above, the second stamp member 4 may apply a force F2 generating a pressure P3 in the upper edge 10. The pressure P3 is different from the pressure P2 generated by the first stamp member 3, which may provide advantages. In many applications, it may be advantageous for the second stamp member 4 to be applied to generate a pressure P3 that is greater than the pressure P2 applied by the first stamp member 3. This may be particularly advantageous if the edge 10 is patterned or contoured and / or if the portion of the sidewall 12 below the edge 10 is patterned or contoured, e.g. with stripes and / or edging, with a protruding profile on the inside 14 and / or outside 15, as shown for example in FIG. 3.

[0021] Further, as shown in FIG. 3, the force F2 applied by the second stamp member 4 may create a pressure P4 near the edge 10 that is greater than the pressure P3 created further down within the sidewall 12 below the edge 10 due to the elastic properties of the fiber.

[0022] The invention provides a great flexibility for the production of textile products, for example to achieve a higher density at the edge 10 than at the bottom 11. The higher local density at the edge can reduce the penetration force of moisture and liquids. Furthermore, it facilitates the easy production of edges with a desired appearance, for example straight and even surfaces. Furthermore, it facilitates the easy production of side walls arranged with protruding elements, for example streaks and / or edging. The material is partially composed of natural fibers.

[0023] Preferably, the fibrous material in the textile product 1 is in the form of natural fibres from wood. Furthermore, the moisture content in the pre-cut (e.g. disc-shaped) material before pressing should not exceed 20% of the fibre weight.

[0024] Furthermore, the entire pre-cut blank can be pressed down into the pad 2 below the top surface of the pad 2, forming the top edge 11 to create a product with a given height and volume of material. The secondary pressing can achieve the desired result, although the fibers have been rearranged during pressing with the first stamp member 3. Thus, the final product can be successfully realized without any problems regarding wrinkle formation and / or local differences at the top edge of the pre-finished product, despite slight density variations at the top edge 11. In particular, after forming, the side walls of the cup-shaped product can be advantageously pressed by applying a force P2, which is smaller compared to the force P1 applied by the first stamp member 3, in a limited horizontal plane. The second stamp member can be seen as a kind of shape reconstruction, which can also serve to shape the inner or outer configurations with various void thicknesses or shapes, for example embossings, reinforcements or streaks, as in FIG. 3.

[0025] An additional advantage is that the present invention allows for shaping of surfaces with precise patterns or contours, shapes that would not be possible if cutting was required to shape the final product.

[0026] According to a variant of the invention (not shown), a second stamp member 4 can be arranged to cut off an unwanted part (not shown) of the final textile product 1, for example at a given distance from the bottom. Preferably, first the pressing edge 41 of the second stamp 4 first at least partially presses the edge 10, and in a final step the cutting edge (not shown) of the second stamp finally both compresses the edge 10 and cuts off the unwanted excess.

Claims

1. A method for pressing a textile product by means of a press pad device (2) and a stamp device (3, 4) at high pressure and temperature, said textile product (1) having a bottom (11) and an edge (10), said stamp device (3, 4) comprising two stamp members (3, 4), a first stamp member (3) forming at least said bottom (11) and a second stamp member (4) forming said edge (10), said second stamp member (4) stopping at a given distance (H12) away from said bottom (11) to position said edge (10) at the furthest distance from said bottom (11), said second stamp member (4) being movable along an outer edge of said first stamp member (3), wherein the press moulding method is characterised in that the textile product also comprises a side wall (12) and that after forming at least the bottom part (11), an upper edge part (10A) of the textile product (1) is positioned in the cavity (22) of the press pad device (2).

2. The press molding method according to claim 1, wherein the side walls (12) extend in a direction perpendicular to a horizontal plane including the bottom (11).

3. 2. The press moulding method according to claim 1, wherein the first stamp member (3) forms at least a part of the base (11) before the second stamp member (4) starts to form the edge (10).

4. 3. The press moulding method according to claim 1 or 2, wherein all parts of the upper edge (10A) are located below an upper surface (21) of the body (20) of the press pad device (2).

5. The press moulding method according to any one of claims 1 to 3, wherein the second stamp member (4) at least partially cuts off unnecessary parts of the final textile product (10) at a given distance (H12) away from the bottom (11).

6. 5. The press moulding method according to claim 1, wherein the second stamp member (4) stops pressing at a given distance (H4B) relative to the position (H0) of the press pad device (2) and / or at a given position relative to the first stamp member (3), such that the edge (10) is positioned at a given distance.

7. 6. The press moulding method according to claim 1, wherein the end position of the first stamp member (3) stops pressing at a given position (H3B) relative to the position (H0) of the press pad device (2) so as to reach a given thickness (t11) for the bottom part (11).

8. 7. The method according to claim 1, wherein forces (F1, F2) are applied to the first and second stamp members (3, 4), whereby a different pressure (P2, P3) is achieved in the edge (10) when pressing simply with the second stamp member (3) compared to when pressing also with the second stamp member (4), preferably a higher pressure (P3) is achieved when pressing with the second stamp member (4).

9. 2. The press moulding method according to claim 1, wherein the material partly comprises natural fibres, preferably natural fibres from wood.

10. 2. The press moulding method according to claim 1, wherein the moulding temperature is between 150 and 250° C. and the pressure at the bottom (11) is at least 200 bar.

11. 2. The press molding method according to claim 1, wherein the amount of water in the material does not exceed the amount of fiber, preferably the weight of water in the material does not exceed 20% of the weight of fiber.

12. 2. A press moulding method according to claim 1, wherein the edge (10) and / or the side wall (12) are provided with a pattern and / or contour (14, 15).

13. A textile press mould comprising a press pad device (2) and a stamp device (3, 4) arranged to form a textile product (1) with a bottom (11) and an edge (10), said stamp device (3, 4) comprising two stamp members (3, 4), a first stamp member (3) arranged to form at least the bottom (11) of said textile product (1) and a second stamp member (4) arranged to form said edge (11) of said textile product, said second stamp member (4) arranged to stop at a given distance (H12) away from said bottom (11) to position said edge (10) at its furthest distance from said bottom (11), said second stamp member (4) arranged to move along an outer edge of said first stamp member (3), wherein the second stamp member (4) is arranged to stop at a given distance (H12) away from the bottom (11) and also forms the side walls (12) of the textile product (1) and the upper edge (10A) of the textile product (1) in the cavity (22) of the press pad device (2).

14. A textile product comprising a base (11), vertical side walls (12) and an edge (10), characterized in that the edge (10) has a higher density than a portion of the side walls (12) closer to the base (11).

15. 15. The textile product according to claim 14, wherein the portion of the side wall (12) between the edge (10) and the bottom (11) has a pattern or profile, preferably having a profile protruding inwards (14) and / or outwards (15), more preferably having a profile forming streaks and / or borders.

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