Method and tool for providing a breakable defect in fibrous material molded body and fibrous material molded body with a breakable defect

Abstract

A method for producing a perforable weak point in molded bodies made of fibrous material, a tool for producing a perforable weak point in molded bodies made of fibrous material and a molded body made of fibrous material are described, comprising at least one surface section which has at least one area with a perforable weak point.

Description

Technical field

[0001] A method for producing a perforable weak point in molded bodies made of fibrous material, a tool for producing a perforable weak point in molded bodies made of fibrous material and a molded body made of fibrous material are described, comprising at least one surface section which has at least one area with a perforable weak point. background

[0002] Fiber-containing materials are increasingly used to manufacture packaging for food (e.g., trays, capsules, boxes, etc.) and consumer goods (e.g., electronic devices, etc.), as well as beverage containers. These fiber-containing materials can contain natural fibers, which are obtained, for example, from renewable resources or recycled paper. The natural fibers can be mixed with water and, if necessary, other additives such as starch in a pulp and then shaped. Additives can also affect the color, barrier properties, and mechanical properties. A pulp can contain, for example, 0.1 to 10% by weight of natural fibers. The proportion of natural fibers can vary depending on the manufacturing process used for the packaging, etc., and the product properties of the product being manufactured. Fibers such as...Natural fibers can also be introduced into molds in a dry state and processed or shaped within them. Alternatively, such fibers can be processed into raw materials for subsequent shaping. Raw materials for further processing can include, for example, sheets or webs, such as airlaid, fluff pulp, paper, etc., as well as multi-layer arrangements of the aforementioned materials, made from a fiber-containing material, which are then formed in a mold.

[0003] Manufacturing processes for products or molded parts made from a fiber-containing material include a wet process, in which the molded parts are pressed from fibers that are drawn from an aqueous suspension and compressed into finished parts in one or more process steps under heat and pressure. Another process involves a dry process, in which a relatively loose fiber composite (e.g., airlaid) with low moisture content is compressed into finished parts under high pressure and heat.

[0004] When using fibrous products or molded parts, for example as lids or similar items, a local weak point is often required that can be easily breached. This weak point must be designed in such a way that, when closed, it provides sufficient sealing against external and internal influences (e.g., liquids, dust, etc.). Furthermore, the weak point must be easy to open, for example, with a straw. Other designs may include a hinged lip or similar feature that is partially connected to an adjacent area and, after a part is separated, can be tilted around a section firmly attached to that area to reveal a drinking opening.Such weak points are also necessary in coffee capsules made of fibrous material to allow the capsules to be punctured without damaging the entire structure of the capsule due to the fibrous material.

[0005] One possibility is perforation, where small, completely punched areas are separated by intervening ribs. However, this method does not achieve a complete barrier or seal in the punched areas. Another way to reduce the layer thickness in the area of ​​a weak point has the disadvantage that, due to the fiber content of the material, the weak point can tear when punctured. This is because the fibers extend across the weak point into the remaining connected area, causing significant damage to the surrounding area. Since the orientation and type of fibers (e.g., fiber length) can vary for each molded part, it is not possible to maintain a consistent effect on the weak points, and thus prevent tearing, across a large number of molded parts when the weak points are punctured.Furthermore, such a reduction in layer thickness can only be achieved with considerable effort. This applies in particular to maintaining specific layer thicknesses so that the weak point can be penetrated with a defined force while simultaneously ensuring sufficient stability of the weak point.

[0006] However, the designs known from the prior art for such weak points in molded parts made of a fibrous material have the disadvantage that they can either be easily opened, but above all do not provide a reliable sealing effect and barrier, or they provide a sufficient sealing effect, but are very difficult to open. Task

[0007] The task is therefore to provide a solution that overcomes the disadvantages of the prior art and offers a solution for perforable weak points in molded parts made of fibrous material. These weak points should be simple in design, possess sufficient barrier and sealing properties, and be easy to open without damaging the molded parts. Furthermore, the weak point should be reproducibly designed so that a large number of molded parts with identical properties, particularly in the area of ​​the weak point, can be produced. Solution

[0008] The aforementioned problem is solved by a method for producing a penetrable weak point in molded bodies made of fibrous material, wherein the method comprises the following steps: Providing a shaped body made of a fibrous material having at least one surface section, completely cutting through at least one area of ​​the at least one surface section, and pressing together the at least one previously completely cut through area, wherein the fibrous material in the at least one cut through area is pressed against itself and thereby creates a connection in the at least one area which is weaker than the connection of the fibrous material in the remaining area of ​​the at least one surface section.

[0009] In this process, the fibrous material on the opposing surfaces at the separation point (e.g., cut surfaces) of at least one area is pressed together after being completely cut through. This creates a force-fit connection between the surfaces at the separation point, forming the penetrable weak point. A penetrable interface can be designed to be punctured, allowing, for example, piercing with a straw or similar object. Pressing the previously completely cut area together creates a weak point that is sufficiently strong to prevent unwanted penetration by substances, etc., and can simultaneously be easily broken or punctured without damaging the surface area surrounding the at least one region containing the weak point.A material-bonded connection between fibers of the fibrous material at the separated points does not exist in the fully formed weak point after pressing.

[0010] In further variations, the molded body can consist solely of the fiber-containing material and, for example, lack any lamination. The surface section can also be flat or curved, with at least one area following the contour of the surface section.

[0011] Compared to known designs, the creation of weak points is easily implemented and allows for the production of a large number of molded parts with identical properties in the area of ​​the weak point. In particular, the weak points of all molded parts exhibit the same behavior when broken or punctured and do not damage the surface section or at least one area.

[0012] Cutting through at least one area and then pressing the at least one area together can be easily implemented from a process engineering perspective.

[0013] The at least one area itself can be designed to be straight, curved, round, angular, etc., at least in sections.

[0014] In further embodiments, the layer thickness of the fiber-containing material can be reduced in at least one area. This reduction in layer thickness can occur during pressing, thereby increasing the force on the opposing surfaces at the interface. A suitable pressing tool with a sufficiently large pressing surface can ensure that the fiber-containing material does not shift during pressing. This means that the orientation and shape of the surface section can be maintained even during pressing. Additionally, the layer thickness of a section adjacent to the at least one area can also be reduced.

[0015] In further details, pressing does not create a material-bonded connection between the fibers of the fiber-containing material in at least one area.

[0016] In further embodiments, the pressing process can be carried out at a temperature in the range of 1 to 250 °C. Preferably, the pressing process can be carried out from approximately room temperature, i.e., 20 °C.

[0017] In further versions, the pressing can take place at a pressure in the range of 1 to 250 N / mm², in particular in the range of 100 to 200 N / mm².

[0018] In further embodiments, several areas within at least one surface section can be cut through, with the multiple areas being separated from each other by fibrous material that remains intact. In this process, bridges or micro-connections can remain between the completely cut areas, providing sufficient stability to the cut areas and enabling them to bear forces across the weak point.

[0019] In further embodiments, the multiple areas and the fibrous material separating the multiple areas can be pressed together, whereby the pressing can be carried out jointly, so that the fibrous material between the separated areas is also pressed together.

[0020] In further versions, at least one area and / or at least one surface section can be laminated after pressing to provide an additional coating for a barrier, etc.

[0021] In further embodiments, the provision of the molded part can additionally include a manufacturing step in which fiber-containing material is formed into a molded part. Such a manufacturing step precedes the formation of the molded part and can, for example, be carried out in a single system. Alternatively, the molded part can be produced beforehand and then fed to a device for creating weak points. The manufacturing step can, for example, involve forming molded parts from a pulp or from a relatively dry material (e.g., airlaid, etc.).

[0022] In further embodiments, the at least one area can be moistened after being cut and before being pressed together. This moistening can positively influence the subsequent pressing process, resulting, for example, in stronger compression and thus greater pressure on the separated surfaces (a stronger force-fit connection), since moister material – depending on the material type and processing – can be pressed together more easily. No material bond is formed in this process, so the advantage of the force-fit connection at the weak point is retained.

[0023] In further embodiments, the cutting and / or pressing of at least one area can take place on opposite sides of at least one surface section. A reduction in layer thickness on both sides can also occur.

[0024] In further embodiments, a pattern spanning at least one severed area can be embossed into a surface on at least one side during the pressing process. In other embodiments, the embossing can occur simultaneously with the pressing. The pattern can strengthen the bond at the weak point, as it achieves further partial consolidation through the embossing pattern penetrating deeper into the fiber-containing material, and simultaneously allows pressing of opposing surfaces in a different orientation or direction at the separation point.

[0025] The aforementioned problem is further solved by a tool for producing a penetrable weak point in molded parts made of fibrous material, comprising at least one cutting element and at least one punch, wherein the at least one cutting element is received in the at least one punch and is displaceable relative to the at least one punch, wherein, for producing a penetrable weak point, the at least one cutting element and the at least one punch are jointly displaceable and the at least one cutting element protrudes from the at least one punch, wherein, after cutting through at least one area of ​​a fibrous material, the at least one cutting element can be held against at least one stop by the joint displacement of the at least one cutting element and the at least one punch.so that, upon further displacement of the at least one punch, a pressing surface of the at least one punch can be pressed against the at least one area and the at least one cutting element plunges into the at least one punch.

[0026] The design of the tool as a combined cutting and pressing device enables the cutting of fibrous material in at least one area and the pressing of the at least one cut area in a single operation. The at least one punch and the at least one cutting element are coupled in such a way that, when the tool closes, the fibrous material is first cut in at least one area, and with further movement in the closing direction, the previously cut area is pressed. For this purpose, the at least one cutting element can be inserted into the at least one punch and is, for example, mounted in the punch by a spring element, so that the cutting element can be automatically pressed into a receptacle in the punch when a lower end position is reached. The end position can be, for example,This is achieved when the cutting element has completely cut through the fibrous material and comes into contact with a counter surface of the tool, which also serves as a stop for the cutting element.

[0027] The aforementioned problem is further solved by a shaped body made of fibrous material, comprising at least one surface section, wherein the at least one surface section has at least one area with a penetrable weak point, wherein the penetrable weak point has a separation point with opposing surfaces, wherein the opposing surfaces of the separation point are produced by separating the fibrous material, and wherein the fibrous material is positively connected to each other at the surfaces of the separation point.

[0028] The design of the weak point provides sufficient sealing while allowing for easy opening without damaging or destroying the surface area surrounding it. For further information regarding the advantages and design of the molded part, please also refer to the descriptions of the weak point production process and the tooling required.

[0029] In further embodiments, the at least one surface section in the area with the penetrable weak point can have a lower layer thickness compared to adjacent areas of the at least one surface section.

[0030] Furthermore, in other versions, the fiber-containing material in the area of ​​the penetrable weak point can exhibit greater compression than in adjacent areas of at least one surface section.

[0031] Further features, designs and advantages will become apparent from the following presentation of exemplary embodiments with reference to the figures. Brief description of the characters

[0032] The drawings show: Fig. 1 a schematic representation of the creation of a weak point in a region of a surface section of a molded body; Fig. 2 schematic representations of the formation of weak points in molded bodies; Fig. 3 schematic representations of a weak point with an embossing; Fig. 4 a schematic representation of a weak point in a sectional view; Fig. 5 another schematic representation of the creation of a weak point in a region of a surface section of a molded body; Fig. 6 yet another schematic representation of the creation of a weak point in a region of a surface section of a molded body; and Fig. 7 a schematic representation of a method for creating penetrable weak points in molded bodies made of a fibrous material. Detailed description of implementation examples

[0033] The following are exemplary embodiments of the technical teaching described herein, with reference to the figures. The same reference numerals are used in the figure descriptions for identical components, parts, and processes. Components, parts, and processes that are immaterial to the technical teaching disclosed herein or that are obvious to a person skilled in the art are not explicitly shown. Features given in the singular are also included in the plural unless explicitly stated otherwise. This applies in particular to terms such as "a" or "an".

[0034] Fig. 1Figure 1 shows a schematic representation of various steps in the production of a weak point 24 in an area 22 of a surface section 20 of a molded body 10 made of a fibrous material. Molded bodies 10 can, for example, be formed from a fibrous suspension (pulp) in a preliminary manufacturing step. Alternatively, molded bodies 10 can be formed from a paper-like layer with at least one layer. In a molding process, the molded bodies 10 can be brought into a three-dimensional shape and cured. The molded bodies 10 can, for example, be formed as a lid, as shown in Figure 1. Fig. 2 shown. However, shaped bodies 10 can also be formed into other shapes and, for example, cups, bowls, capsules, etc.

[0035] After the provision of molded parts 10, surface sections 20 can be provided with a weak point 24. Surface sections 20 can be located, for example, on flat areas of the material or on curved areas of the material. The formation of weak points 24 is not subject to any restrictions with regard to the (surface) structure of the material. This only requires an adaptation of the tool for the production of weak points 24 or a corresponding design of the tool.

[0036] Fig. 1a Figure 1 shows a schematic representation of a first manufacturing step for producing weak points 24 in a surface section 20 of a molded body 10 made of a fiber-containing material. In the illustrated embodiment, a section of the molded body 10 is shown. The molded body 10 can, for example, be a lid, as shown in Figure 1. Fig. 2The weak point 24 is formed in a flat surface section 20. For this purpose, the molded body 10 is placed on a tool part that serves as a counter-surface 44. The counter-surface 44 or the tool part can be made of a suitable material, in particular a metal or a metal alloy, or at least have a metal or metal alloy on the contact surface for the surface section 20. The counter-surface 44 can completely replicate the geometry of the molded body 10, so that the molded body 10 is in full contact with the counter-surface 44 on its lower surface. In further embodiments, the counter-surface 44 can extend essentially over the area in which the weak point 24 is formed.

[0037] Fig. 1aFigure 1 shows the surface section 20 made of fibrous material of a molded body 10, which rests on the counter surface 44 in at least one area 22. To create the weak point 24 in area 22, a cutting die 40, which serves as a cutting element, is first positioned and then lowered from above in the direction of the arrows. The design of the cutting die 40 defines the width and length of the cut through the fibrous material after cutting. In further embodiments, several cutting steps can be carried out successively and / or using cutting dies 40 arranged one behind the other or side by side, for example, to create cuts in the fibrous material that are long and / or curved, closed, and / or "perforated." A perforated shape includes, for example,Designs with a multitude of completely cut areas separated by webs 30, wherein the fibrous material in the area of ​​the webs 30 is not cut or only partially cut, i.e. the layer thickness of the fibrous material in the area of ​​the webs 30 may be reduced compared to the fibrous material in the remaining surface section 20.

[0038] Fig. 1b Figure 1 shows a state where the cutting blade 40 has completely severed the fibrous material in area 20. The lower, pointed cutting edge of the cutting blade 40 abuts the counter surface 44 and cannot be displaced further. The fibrous material in the separation point 26 is forced to the side, which can lead to a slight accumulation of material in area 22 because downward or lateral displacement is not possible or only possible to a limited extent. The accumulation shown in the separation point 26 is the simplest displacement option for the material.

[0039] After separation, the fibrous material at the separation point 26 has opposite surfaces 28 that are completely separated from each other and no longer have a material-bonded connection.

[0040] As in Fig. 1cAs shown in the figure, a gap exists between the surfaces 28 at the separation point 26 after stamping. Substances, liquids, etc., can pass through this gap via the weak point 24. Therefore, a die, which in the illustrated embodiment is an embossing die 42, is positioned relative to the separation point 26 and moved towards the gap or separation point 26 in the direction of the arrows. The embossing die 42 can have a lower embossing surface that extends at least over the length and width of the separation point 26 or the gap. In the illustrated embodiment, the embossing die 42 has a width that extends laterally at least 3 to 10 mm beyond the separation point 26 in both directions. In the longitudinal direction, i.e., in the direction shown in the drawing, the embossing surface of the embossing die 42 can extend by the same amount of at least 3 to 10 mm beyond the separation point 26.

[0041] In the illustrated embodiment, the embossing surface of the embossing die 40 is flat, allowing the surface section 20 to be pressed against the separation point 26 in the area 22 over a definable embossing area defined by the embossing surface of the embossing die 40. During pressing, the embossing die 40 is pressed against the area 22 until a force-fit connection is formed between the surfaces 28 at the separation point 26, thereby closing the gap. In the illustrated embodiments, the embossing area, i.e., the area of ​​the fibrous material being pressed, extends beyond the separation point 26. This also compresses the accumulation of material in the area of ​​the separation point 26, so that no accumulation remains after pressing due to the separation or cut.

[0042] Further details include, for example, sections with closed structures (e.g., circular weak points 24; see e.g. Fig. 2f ) only exhibit a lateral extension of the embossing surface of an embossing die. The correspondingly pressed surface of the surface section 20 can, in the form of a weak point 24, extend as a closed structure, for example, circularly with a larger diameter than the weak point 24 itself.

[0043] In further versions, the embossing surface can be provided with a pattern or the like, so that an embossing with a corresponding pattern, such as in, is present on the surface of the pressed area. Fig. 3 This can be demonstrated by creating embossing surfaces. For this purpose, the embossing surface can, for example, have raised areas and / or depressions in the form of parallel and / or intersecting grooves, lines, etc. Furthermore, such raised areas and / or depressions can be curved along the embossing surface.

[0044] Fig. 1dFigure 1 shows surface section 20 with area 22, which has a penetrable weak point 24, after pressing. Area 22 is compressed compared to the rest of surface section 20 and has a small layer thickness. The protrusions or material accumulations are flattened by the cut. In addition, the compression of the material presses the surfaces 28 against each other, so that a force-fit connection is established between the surfaces 28. In order to achieve a force-fit connection and prevent compensatory movement of the fiber-containing material, the embossed surface or embossed area is preferably dimensioned accordingly, i.e., made wide. The force-fit connection provides a sealing solution for the weak point 24, while at the same time, penetrating or piercing is easy because there is no material bond. In addition, when piercing (e.g., by cutting), the material is easily removed.(using a straw or the like) does not cause uncontrolled tearing or other damage to the surface section 20, because a "weak point" is present and the weak point 24 already has a completely separated area.

[0045] Fig. 2 shows schematic representations of the formation of weak points 24 in molded bodies 10, wherein the in Fig. 2 The molded body 10 shown is designed as a lid. The lids are made of a fibrous material. The lids or molded bodies 10 of the Fig. 2aFigures ) to f) have a three-dimensional structure with a circumferential rim 12, which can be placed on a cup and locked into place with the cup rim. The lids have a substantially circular surface section 20 in the center. This surface section 20 can have various design features. For example, the surface section 20 has a depression, as schematically indicated. Furthermore, the surface section 20 of each of the lids or molded parts 10 shown has a weak point 24, which was manufactured according to a manufacturing process described herein and thus has a separation point 26. This separation point was pressed together after a stamping step, so that a force-fit connection between the separated surfaces 28 was created in the separation area.

[0046] Fig. 2aFigure 1 shows the formation of a weak point 24 with three converging cuts separated by a central ridge 30. In this embodiment, the embossing area can extend over the ridge 30.

[0047] Fig. 2b ) shows a modification in which the weak point 24 has four converging cuts that are separated from each other by a central web 30.

[0048] Fig. 2c ) shows a variation of the execution of Fig. 2b), wherein the four converging cuts are divided by further webs 30. The cuts or the individual areas, which were previously completely severed and subsequently pressed, can have a greater extent, so that despite a larger puncture area (e.g. for straws with a large cross-section, which are used, for example, with thick drinks (milkshakes, etc.)) the weak point 24 has sufficient stability while remaining easily punctured.

[0049] Fig. 2d ) shows a variation of the execution of Fig. 2a ), wherein an additional cut is made between the outer ends of each cut, which is then grouted. In such designs, the weak point 24 can be penetrated almost across its entire surface or separated from the remaining surface section 20.

[0050] Fig. 2e ) shows a variation of the execution of Fig. 2b), wherein an additional cut is made between the outer ends of the cuts, which is then grouted. Even in such designs, the weak point 24 can be penetrated almost across its entire surface or separated from the remaining surface section 20.

[0051] Fig. 2f Figure 1 shows an embodiment with an essentially circular area 22, which has a multitude of cuts that completely separate the fibrous material and are subsequently pressed together, the individual cuts being separated by webs 30. In one area, the surface section surrounded by the cuts and the webs 30 has a connection to the remaining surface section 20, so that after breaking through or piercing the weak point 24 in area 22, the area detached from the remaining surface section 20 remains connected to the remaining surface section 20 via a kind of hinge.

[0052] In the Fig. 2In the illustrated designs, the webs 30 can be pressed together with the completely severed areas of the fiber-containing material, or can already be pressed together.

[0053] Fig. 3Figure 1 shows a schematic representation of a weak point 24, which is provided with an embossing 32. An embossing 32 can be applied when pressing a previously cut area 22e of a fibrous material or a surface section 20, for which purpose an embossing surface of an embossing die 42 is appropriately designed and, for example, has a surface with depressions and / or protrusions. An embossing 32 can partially create a stronger compression in the area of ​​depressions in the pressed area of ​​the fibrous material, thereby further strengthening the structure weakened by the cut. Furthermore, an additional force distribution can be achieved in the force-fit connection between the previously separated surface sections across the separation point 26. In addition, a marking of the weak point 24 can be provided, which further facilitates the piercing, as the piercing point can be located quickly.

[0054] Fig. 3a ) shows an embossing 32 with a multitude of parallel indentations inclined at approximately 45° to the separation point 26, which extend, for example, over the entire pressed area. Fig. 3b Figure 32 shows an embossing with multiple intersecting indentations, each running parallel and at 45° or 135° to the separation point 26. The indentations can also extend over the entire pressed area. Fig. 3c Figure 1 shows a design with simply crossed indentations, each running parallel and at 45° or 135° to the separation point 26, the indentations extending over the entire pressed area and their intersection points lying at the separation point 26. Other patterns for an embossing 32 can also be used in further designs.

[0055] Fig. 4Figure 1 shows a schematic representation of a weak point 24 of a further embodiment in a sectional view, wherein the previously cut area 22 was pressed flat on both sides, so that the indentation appears on the opposite sides due to the pressing. Pressing on both sides can, for example, reduce the indentation on only one side, so that it is not perceptible or less perceptible, whereby the same pressing as with one-sided pressing can be carried out.

[0056] Although such indentations are usually barely perceptible, in further embodiments, pressing and thus a depression can be made on the side of a surface section 20, which is not visible in use of the molded part 10. In the exemplary embodiment of Fig. 2 For example, pressing on the non-visible underside of the lid could be effective.

[0057] Fig. 5Figure 1 shows a further schematic representation of the production of a weak point 24 in an area of ​​a surface section 20 of a molded body 10. In the embodiment shown, the tool is equipped with at least one embossing die 42, which has a cutting blade 40 that can be moved into a receptacle 41. The cutting blade 40 can, for example, be pushed out of the receptacle 41 in the unactuated state by means of a spring device (e.g., a compression spring) or the like, and thus protrudes from the lower embossing surface of the embossing die 42. This allows, as shown in Figure 1, the production of a weak point 24 in a surface section 20 of a molded body 10 to be carried out. Fig. 5aAs shown in Figure 1, when the embossing die 42 is moved downwards, a cut is first made in a surface section 20 of fibrous material. In its lower end position, the cutting blade 40 has completely cut through the fibrous material and abuts a counter surface 44 of a lower tool plate. The cutting blade 40 has thus reached its end position and cannot be moved further downwards. If the embossing die 42 is now moved further downwards, as shown in Figure 1, the embossing die 40 is moved further downwards. Fig. 5bAs shown schematically, the cutting blade 40 is no longer moved in the same direction and to the same extent as the embossing die 42, but is displaced relative to the embossing die 42 and pressed into the receptacle 41. This can be done against the force of the spring mechanism. When the embossing surface contacts the fibrous material, the cutting blade 40 is in its maximum position within the embossing die 42 and can, for example, be flush with the lower surface of the embossing area. Subsequently, the embossing die 42 is pressed further against the fibrous material, so that it is compressed in the area of ​​the embossing surface, as described above, and the fibrous material is pressed together in a force-fit manner at the separation point 26.

[0058] After pressing, the embossing die 42 returns to its starting position, and the cutting die 40 can continuously emerge from the receptacle 41. In further embodiments, the displacement of the cutting die 40 relative to the embossing die 42 and together with the embossing die 42 can be mechanically coupled, so that, for example, before the embossing surface of the embossing die touches the fibrous material, the cutting die 40 is fully retracted into the receptacle 41 and can only emerge from the receptacle 41 again when the embossing surface has reached a definable distance from the fibrous material. This can be achieved, for example, by means of a gear arrangement.

[0059] The Fig. 6aFigures ) and b) show a further schematic representation of an embodiment for the production of a weak point 24 in a region of a surface section 20 of a molded body 10, wherein the fibrous material is cut from two sides. For this purpose, for example, punching tools can be used, as shown in Fig. 5 described, are formed, and, for example, have movable dies 40 relative to an embossing die 42. As described in Fig. 6b As shown schematically, compression of the fiber-containing material in area 22 with the separation point 26 can take place from both sides.

[0060] In the embodiments described above, a stamping tool can have several tool elements, so that a multitude of weak points 24 can be simultaneously generated in a multitude of shaped bodies 10. Furthermore, the geometry of the stamping dies 40 shown is exemplary and can be designed to be particularly thin. For example, stamping dies 40 can have a width of approximately 0.5 to 3 mm, with the tip ideally being almost 0 mm wide. In other embodiments, stamping dies 40 can, for example, have a tip or cutting angle of approximately 30–60°. However, stamping dies 40 can be designed differently depending on the requirements. For example, stamping dies 40 can be designed very differently in detail and may differ, for example, with regard to the grind (e.g., single-bevel ground, double-bevel ground, four-bevel ground, etc.).Furthermore, in other versions, punch blades 40 can also be used, which have a rounded tip.

[0061] Fig. 7 shows a schematic representation of a method 50 for producing penetrable weak points 24 in molded bodies 10 made of a fibrous material.

[0062] The process includes the provision 51 of a shaped body 10. The provision 51 can include a forming step, wherein either a forming 52 from a relatively dry fiber material (dry forming) or a forming 53 from an aqueous fiber suspension (pulp) is carried out (wet forming).

[0063] In a so-called wet process, preforms made of a fiber-containing material are first prepared and then compressed under thermal influence. The preforms can be prepared by drawing fibers from an aqueous solution (pulp) and forming three-dimensional preforms that essentially already have the shape of the products to be manufactured. Additionally, additives such as starch, chemical additives, wax, etc., can be added to the pulp to influence the properties of the products (e.g., barrier properties) and their processability. The fibers can be, for example, natural fibers such as cellulose fibers or fibers from a fiber-containing source material (e.g., recycled paper).Since a fibrous pulp containing natural fibers can be used as the starting material for the molded bodies 10, the manufactured molded bodies 10 can themselves serve as starting material for the production of molded bodies 10 or other products after their use, or can be composted, because they can generally be completely decomposed and do not contain any harmful, environmentally hazardous substances.

[0064] The preforms can be further modified and subjected to a pre-pressing step. Subsequently, the preforms are pressed into three-dimensional molded bodies 10 in a hot pressing device under pressure and heat.

[0065] Furthermore, the shaped bodies 10 can be formed from a loose cellulose web (airlaid) or paper.

[0066] To create a weak point 24, the previously manufactured shaped body 10 is then inserted 54 into a tool which has means for creating weak points 24.

[0067] Subsequently, the shaped part 10 is punched 55 or cut from fibrous material in at least one surface section 20, whereby the fibrous material is completely severed in an area 22. The punching 55 can be carried out by relative displacement of two tool parts, e.g., punching blade 40 and counter-position 44.

[0068] Subsequently, the previously completely separated area 22 is pressed 56 with another tool component, e.g., an embossing die 42. The pressing 56 can take place in the same tool or in a different tool. Furthermore, the embossing can be carried out in the same station with a combined tool, such as in the Fig. 5 and 6The pressing process can be carried out, or with two different tools arranged in successive stations of a tool. The pressing 56 can be achieved by relative displacement of two tool parts, e.g., embossing die 42 and counter-position 44. During pressing 56, the layer thickness of the fiber-containing material in the area 22 with the separation point 26 or the cut is compressed relative to the remaining surface section 20, so that the fiber-containing material is additionally compacted and pressed forcefully together on opposing surfaces 28 in the area of ​​the separation point 26.

[0069] The pressing 56 can be carried out according to the layer thickness of the unpressed fiber-containing material, the material type and composition, as well as the cut length and width, at pressures in the range of 1 to 200 N / mm². Furthermore, in other embodiments, the embossing surface of an embossing die 42 can be temperature-controlled to improve the compression of the fiber-containing material in the area 22 with the separation point 26. Preferably, the pressing 56 is carried out at temperatures of 50 to 150 °C.

[0070] In further embodiments, after punching 55 and before pressing 56, optional moistening 60 of the area 22 can take place, whereby during pressing 56, the area 22 can be dried at correspondingly higher temperatures (e.g., between 90 and 150 °C). No material bond is formed, so the advantage of the force-fit connection at the weak point 24 is retained.

[0071] After pressing 56 or simultaneously with pressing, the separation point 26 can be embossed with an embossing die 42, as in Fig. 3 as described, or with a separate tool.

[0072] Subsequently, the molded part 10, which has at least one defect 24, can be ejected 57 and then subjected to post-treatment 58 in another facility or in the same facility. Post-treatment 58 can include, for example, lamination 59, printing, etc. In further embodiments, the molded parts 10 can be treated in other ways after their manufacture to achieve specific properties.

[0073] The formation of shaped bodies 10 can vary depending on the desired shape. This allows for the simple production of gap-free weak points 24 in various types of pulp-based fiber products, which can be used in different areas and for various purposes. The gap-free weak points 24 of the technical teaching disclosed herein are achieved by completely cutting through a fiber-containing material and subsequently pressing the completely cut area together. The pressing extends beyond the cut point 26 to exert sufficient pressure on the cut point 26 from the adjacent areas. The area that must be pressed depends on the design of the cut point 26 (length, cutting depth, i.e., thickness of the fiber layer) and the material used, as well as the stability and desired resistance to puncture or breakage of the weak point 24. Reference symbol list

[0074] 10 Shaped body 12 Edge 20 Surface section 22 Area 24 Weak point 26 Separation point 28 Surface 30 Web 32 Embossing 40 Die 41 Holder 42 Embossing die 44 Counter position 50 Process 51-60 Process steps

Claims

1. A method for producing a penetrable weak point in molded bodies made of fibrous material, the method comprising the following steps: - providing a molded body made of a fibrous material having at least one surface section, - completely cutting through at least one area of ​​the at least one surface section, and - pressing the at least one previously completely cut through at least one area, wherein the fibrous material in the at least one cut through area is pressed against itself and thereby a connection is created in the at least one area which is weaker than the connection of the fibrous material in the remaining area of ​​the at least one surface section.

2. The method of claim 1, wherein the layer thickness of the fiber-containing material is reduced in at least one region.

3. Method according to claim 1 or 2, wherein no material-bonded connection of the fiber-containing material is produced in at least one area by pressing.

4. Method according to any one of claims 1 to 3, wherein the pressing takes place at a temperature in the range of 5 to 250 °C.

5. Method according to any one of claims 1 to 4, wherein the pressing is carried out at a pressure in the range of 1 to 200 N / mm². 2 This has been done.

6. Method according to any one of claims 1 to 5, wherein several areas in the at least one surface section are cut through, wherein the several areas are separated from each other by fibrous material which is not cut through.

7. Method according to claim 6, wherein the multiple areas and the fiber-containing material separating the multiple areas are pressed together.

8. Method according to any one of claims 1 to 7, wherein the at least one area and / or the at least one surface section is laminated after pressing.

9. Method according to any one of claims 1 to 8, wherein the provision of the molded body additionally comprises a manufacturing step, wherein fiber-containing material is formed into a molded body.

10. Method according to any one of claims 1 to 9, wherein after cutting the at least one area and before pressing the at least one area, moistening of the at least one area takes place.

11. Method according to any one of claims 1 to 10, wherein the cutting and / or pressing of the at least one area is carried out on opposite sides of the at least one surface section.

12. Method according to any one of claims 1 to 11, wherein during pressing a pattern spanning the at least one cut area is embossed into a surface on at least one side.

13. Tool for producing a penetrable weak point in molded bodies made of fibrous material, comprising at least one cutting element and at least one punch, wherein the at least one cutting element is received in the at least one punch and is displaceable relative to the at least one punch, wherein, for producing a penetrable weak point, the at least one cutting element and the at least one punch are jointly displaceable and the at least one cutting element protrudes from the at least one punch, wherein, after cutting through at least one area of ​​a fibrous material, the at least one cutting element can be held against at least one stop by the joint displacement of the at least one cutting element and the at least one punch.so that, upon further displacement of the at least one punch, a pressing surface of the at least one punch can be pressed against the at least one area and the at least one cutting element plunges into the at least one punch.

14. Molded body made of fibrous material, comprising at least one surface section, wherein the at least one surface section has at least one area with a perforable weak point, wherein the perforable weak point has a separation point with opposing surfaces, wherein the opposing surfaces of the separation point are produced by separating the fibrous material, and wherein the fibrous material is positively connected to each other at the surfaces of the separation point.

15. Molded body according to claim 14, wherein the at least one surface section in the area with the perforable weak point has a smaller layer thickness compared to adjacent areas of the at least one surface section.

16. Molded body according to claim 14 or 15, wherein the fiber-containing material in the area of ​​the penetrable weak point exhibits a greater compression than in adjacent areas of the at least one surface section.

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