Method for producing three-dimensional cellulose products

Abstract

The invention relates to a method for producing three-dimensional cellulose products, comprising the following steps: • providing a web material, which is a web-like nonwoven based on cellulose fibres, • transporting the web material through successive processing stations, • pre-cutting contours of the cellulose products in the web material in a first processing station, • press-forming the cellulose products within the pre-cut contours in the web material in a second processing station, • punching out the press-formed cellulose products from the web material in a third processing station (44), wherein the cellulose products are not filled before punching out, if they are designed as containers for being filled with goods.

Description

[0001] Method for producing three-dimensional cellulose products

[0002] The invention relates to a method for producing three-dimensional cellulose products.

[0003] The three-dimensional cellulose product includes, for example, bowls, plates, cups or other containers, spoons, forks, knives or other disposable eating utensils, packaging for food or other goods, inserts for outer packaging, holders for writing instruments or other products for technical applications.

[0004] EP 4043353 A1 describes a process for manufacturing a cellulose product, comprising the steps of dry forming a cellulose blank in a dry forming unit, arranging the cellulose blank in a forming tool, heating the cellulose blank to a forming temperature in the range of 100 °C to 200 °C, and pressing the cellulose blank in the forming tool with a forming pressure of at least 1 MPa. In the dry forming unit, a cellulose raw material is dissolved into cellulose fibers. From the dissolved cellulose fibers, a web of cellulose fibers (airlaid) is produced by laying air onto an air-permeable, vacuum-assisted conveyor belt, and this web is compacted or calendered. The web-shaped cellulose blank produced in this way is fed intermittently to the forming tool via a feeding unit. In the forming tool, the cellulose product is formed and die-cut from the web.In practical implementation of the process, a tissue is applied to the web-shaped cellulose blank, AKD is sprayed on as a water barrier, and the product is dried in an oven for approximately 15 minutes. Because the production of the web-shaped cellulose blank and the cellulose product are carried out inline, the system is complex and the production speed is limited. Applying and drying a water barrier further increases the system complexity and restricts cycle times and throughput. The forming tool is highly complex, prone to wear and tear, and susceptible to malfunctions because it simultaneously forms and punches out the product. EP 3 140 200 Bl describes a process for producing three-dimensional molded parts from a web of a planar, plastically deformable fiber material by deep drawing with a punch and an associated drawing die.The fibrous material can be formed through a relative movement between the punch and the die. In this process, a round, rectangular, oval, or irregular blank for the molded part is connected to the fibrous web via at least one web during deep drawing and otherwise detached from the web by at least one relief cut. This connection to the web can be used to manipulate the molded parts by positioning the packaging material precisely for filling and sealing, and then cutting the finished package from the web. This requires an inline connection between a molding machine for producing the molded parts and a filling and sealing machine. Furthermore, there is a risk of process disruptions because the filled molded parts may not precisely follow the web's movement and / or may tear away from it before being cut out.

[0005] Based on this, the invention aims to provide a less complex, less wear-prone and less prone to malfunctions, as well as a method for producing three-dimensional cellulose products that enables higher cycle rates and throughputs.

[0006] The problem is solved by a method according to claim 1. Advantageous embodiments of the method are specified in the dependent claims and in the description.

[0007] The inventive method for producing three-dimensional cellulose products comprises the following steps:

[0008] • Providing a web-shaped nonwoven fabric (web material) based on cellulose fibers,

[0009] • Transporting the track material through successive processing stations,

[0010] • Pre-cutting the contours of the cellulose products in the web material in a first processing station, • Pressing the cellulose products within the pre-cut contours in the web material in a second processing station and

[0011] • Punching out the press-molded cellulose products from the web material in a third processing station.

[0012] In the process according to the invention, the cellulose products are manufactured from a web-shaped nonwoven fabric based on cellulose fibers. The production of the cellulose products is divided into three steps, which are carried out in three successive processing stations through which the web material is transported. In a first step, the contours of the cellulose products are pre-cut in the web material at a first processing station. In a second step, the cellulose products are press-molded within the pre-cut contours in the web material at a second processing station. In a third step, the press-molded cellulose products are die-cut from the web material at a third processing station. By dividing the forming of the cellulose products into three successive steps, the complexity of the tools in the various processing stations can be kept comparatively low.This reduces the effort required for the technical implementation of the process. The relatively simple tools exhibit low wear and are less prone to malfunctions. Because only a portion of the cellulose product forming process is carried out at each of the various processing stations, higher cycle rates and throughputs can be achieved.

[0013] Pre-cutting the contours of the cellulose products in the web material before compression molding reduces the effort required for compression molding and enables particularly deep and precise compression molding of the web material. For example, drinking cups with a depth of 8 cm can be compression molded (deep-drawn). Furthermore, pre-cutting has the advantage that the wall thickness of the cellulose product is nearly uniform across the entire cross-section and does not decrease significantly towards the edges. Die-cutting the compression-molded products from the web material in the third processing station, which follows the second processing station for compression molding, has the advantage of being less complex, less prone to wear and tear, and less susceptible to malfunctions than conventional die-cutting in a mold or at the end of a downstream filling and sealing machine.If the compression-molded cellulose products are containers or packaging for filling with food or other goods, they are preferably not filled before being die-cut from the web material. This distinguishes this embodiment of the inventive method from the prior art according to EP 3 140200 B 1. Between the compression-molded cellulose products and the die-cutting of the compression-molded cellulose products, the web material can be transported from the second processing station to the third processing station without any further processing steps taking place.

[0014] By dividing the forming of the cellulose products into three steps, the use of web material with a comparatively high density is made possible, which exhibits sufficient integrity for winding and supplying as roll material. Unlike the conventional prior art process, in which the web material is supplied as loose fluff on a conveyor belt, it is not necessary to carry out the production of the web material inline with the forming of the cellulose products. This enables particularly economical production of the web material in a high-performance plant that supplies the feedstock for forming cellulose products in multiple plants. Supplying the web material as roll material allows for buffering to compensate for fluctuations in the throughput during the forming of the cellulose products.Separating the production of the raw material from the forming of the cellulose products also simplifies the operation of the equipment for producing the web material and forming the cellulose products. Furthermore, providing a web material with comparatively high density and integrity allows for the use of simple transport systems to move the web material through successive processing stations. For example, the web material can be transported using chain guides that grip the web material at its edges and transport it through the processing stations.

[0015] After the die-cut cellulose products are cut from the web material, they can be made available for their intended use. Making them available for their intended use means making them ready for the specific purpose of the cellulose product. For containers or packaging intended for filling with food or other goods, the intended use is filling with goods. Making them available for filling includes both making them available at the manufacturer's site for transport to the filler, and making them available at the filler's site for filling. Similarly, for other cellulose products, making them available for their intended use includes making them available for transport to the end user, as well as making them available for use by the end user.

[0016] According to one embodiment of the invention, the web material is pre-pressed in the areas where the contours of the cellulose products are pre-cut, or during the pre-cutting process, and is not pre-pressed, or pre-pressed to a lesser extent, in the areas where the cellulose products are press-molded. Pre-pressing the web material in the areas where the contours are pre-cut stabilizes the cut edges. As a result, the cut can be smoother during pre-cutting, and dust generation during pre-cutting is reduced. This effect can also be utilized during the subsequent die-cutting of the press-molded cellulose products from the web material.Furthermore, by pre-pressing the contours of the cellulose products, the connection areas become more tear-resistant and better protected against damage during transport of the web material.

[0017] During pre-pressing in the areas where the contours are pre-cut, adjacent edge areas in the web material where the cellulose products are press-formed, as well as areas of the web material located outside the contours, can be pre-pressed. Starting from the contours, the degree of compression of the web material can be constant or decrease with increasing distance from the contours. In particular, in the edge areas of the web material where the cellulose products are press-formed, the degree of pre-pressing can gradually decrease from the contours. The areas of the web material between the contours of the cellulose products can be completely pre-pressed. Specifically, these areas can be uniformly pre-pressed.According to another embodiment, the initial thickness of the web-shaped nonwoven fabric is at least 1 cm and / or the wall thickness of the compression-molded cellulose product is at least 1 mm and / or the material thickness of the pre-pressed areas is less than 1 mm. In the pre-pressed areas, the material thickness of the nonwoven fabric is similar to that of paper. This makes the web material in the pre-pressed areas tensile and tear-resistant, similar to paper.

[0018] According to another embodiment, the initial thickness of the web-shaped nonwoven fabric is 2 to 4 cm and / or the wall thickness of the press-molded cellulose product is 2 to 5 mm and / or the material thickness in pre-pressed areas is 0.1 to 0.8 mm.

[0019] According to another embodiment, the web material comprises several superimposed layers of nonwoven fabric. These layers can be made of the same material or of different materials. Superimposing multiple layers of nonwoven fabric facilitates the production of web materials with high homogeneity, as well as web materials with advantageous properties due to the superimposed layers of different materials. When the material exhibits the highest possible homogeneity, it reduces process variations and defect costs caused by weaknesses in the product due to an inhomogeneous distribution of the fibers. Furthermore, superimposing multiple layers of nonwoven fabric facilitates the production of web materials with advantageous properties due to the superimposed layers of different materials.According to another design, the web material has a layer of virgin fiber on one or both sides and a layer of recycled fiber in between. The side with the virgin fiber layer is particularly suitable for contact with food.

[0020] According to another embodiment, the web material has a barrier fabric and / or a barrier film on one or both sides. The barrier fabric and / or barrier film layer can be designed to prevent or reduce the penetration of moisture, especially water or grease. The barrier fabric and / or barrier film layer can also serve as an aroma and / or water vapor barrier. Web material with such a barrier layer is particularly suitable for the production of cellulose products for food packaging.

[0021] Tissue is an absorbent, finely creped material made entirely or predominantly from cellulose fibers, as defined in DIN 6730. Tissue is typically used in multi-ply form for kitchen paper, paper napkins, facial tissues, and toilet paper. For the barrier tissue, either this type of tissue or a tissue-like material can be used. A tissue-like material is defined as one that is produced using a different drying process compared to tissue. DIN 6730 provides further details on tissue-like materials. The barrier tissue is coated with a moisture-repellent material, such as AKD (alkylated ketene dimers). AKD is used, for example, to make papers and containers made of cellulose fibers water-repellent for liquids.

[0022] According to another design, a barrier film made of PHA, cellophane, PLA or PP is used.

[0023] The supplied web material may already be coated with the barrier fabric and / or barrier film and / or another barrier layer on one or both sides. The barrier fabric and / or barrier film and / or other barrier layer may also be subsequently applied to the supplied web material. Furthermore, web material may be supplied that is already coated with a barrier layer on one side and subsequently coated with a barrier layer on the other side.

[0024] In another embodiment, the web material is coated on one or both sides with a barrier fabric and / or a barrier film and / or another barrier layer during transport to the processing stations. During transport, the barrier layer can be heated by a heating unit, which, for example, generates hot air or includes heating coils, and then pressed firmly onto the three-dimensional cellulose products during compression molding. In yet another embodiment, the web material comprises starch, thermoplastic fibers, and / or another additive that contributes to strengthening the cellulose products. The additive can be added in powder and / or fiber form before the web-like nonwoven fabric is laid down to achieve the best possible homogenization of the additive within the web material.As a result, the cellulose products exhibit uniform strength across their entire cross-section. The additive can be added dry, thus minimizing moisture input, which allows for shorter pressing times and faster cycle times when forming the cellulose products.

[0025] According to another embodiment, the web material comprises at least one layer consisting essentially of cellulose fibers. According to another embodiment, the web material comprises at least one layer consisting exclusively of cellulose fibers.

[0026] According to another embodiment, the web material is produced by dry-laying one or more layers containing cellulose fibers onto a vacuum conveyor belt, suctioning the at least one layer onto the top of the vacuum conveyor belt, and compacting the at least one layer between at least one roller and the vacuum conveyor belt or another substrate. According to yet another embodiment, the web material is formed from at least one layer containing cellulose fibers and compacted by means of at least one roller in such a way that the web material has sufficient density and integrity to be wound up and supplied as roll material.

[0027] In another version, the web material is supplied as roll material. This allows for buffering to compensate for fluctuations in throughput during the forming of the cellulose products.

[0028] According to another embodiment, the web material is provided with a barrier fabric or barrier film on at least one side and / or the web material is provided with a layer of barrier fabric or barrier film on at least one side during transport to the first processing station. This allows the same raw material to be used for different products, which are provided with or without an additional layer of barrier fabric or barrier film, depending on the requirements.

[0029] In another method, the web material is provided in a dry state. A dry state is defined as a condition in which the moisture content of the web material is in equilibrium with the ambient humidity. Providing the web material in a dry state enables shorter pressing times and faster cycle times.

[0030] According to another embodiment, the web material is moistened in at least one processing station before processing. This moistening increases the degree to which the web material can be deformed during compression molding without tearing.

[0031] According to another design, when pre-cutting the contours of the cellulose products in the first processing station, connecting areas that join the pre-cut contours to the rest of the web material are not severed until the cellulose products are die-cut in the third processing station. This ensures that the cellulose products are transported through the various processing stations along with the web material, thus promoting short cycle times and high throughput, and preventing disruptions caused by detached cellulose products.

[0032] According to another design, only sections of the contours of the cellulose products are pre-cut, so that connecting areas remain between adjacent pre-cut sections of the contours and the rest of the web material, which connect the pre-cut contours with the rest of the web material.

[0033] According to another embodiment, the connecting areas are strip-shaped. After compression forming, these strip-shaped areas connect the cellulose products to the rest of the web material, bridging the gap between the outer edge of the cellulose products and the inner edge of the surrounding web material.

[0034] According to another design, the strip-shaped connecting areas have a zigzag pattern in the web material. This allows for the bridging of particularly large gaps between the press-molded cellulose products and the web material to which they are connected via the strip-shaped areas.

[0035] In another embodiment, the bonding areas are evenly distributed around the circumference of the cellulose product contours. This means that the distances between adjacent bonding areas are the same along the circumference of the cellulose product contours. In the simplest case, there are only two bonding areas, spaced apart by half the total circumference of the contour. With three bonding areas, the distance between each adjacent bonding area is one-third of the total circumference of the contour. This even distribution of the bonding areas ensures that the areas defined by the contours are held uniformly within the web material. This is advantageous for smooth material movement through the processing stations and for consistent pre-cutting, compression forming, and die-cutting in the three processing stations.

[0036] According to another embodiment, the web material in the area of ​​the contours of the cellulose products is only partially cut perpendicular to its main expansion surface during pre-cutting, so that the pre-cut cellulose products are connected to the rest of the web material via the uncut areas of the cross-section.

[0037] In another embodiment, the web material is lightly pre-pressed into a three-dimensional shape within the pre-cut contours at the second processing station using a (disc) pin. The three-dimensional cellulose product is then pressed between a positive and a negative part of the mold. Pre-pressing the web material facilitates the compression molding of particularly deep cellulose products and ensures a uniform wall thickness across the entire cross-section.

[0038] According to another embodiment, in the second processing station, the web material is pressed within the pre-cut contours between a positive and a negative part of the forming tool, with the negative part (negative mold) being subjected to a vacuum. Applying a vacuum to the negative mold of the forming tool has the following advantages in particular: applying the vacuum shortly before the mold closes causes the material to be "pulled" forward into the negative cavity. Applying the vacuum during the pressing process accelerates the removal of moisture from the web material.

[0039] According to another embodiment, after compression molding, the cellulose products are ejected from the positive and / or negative part of the mold by means of a (disc) pin. The (disc) pin is used to release the cellulose products from the mold, thus achieving simple and reliable separation of the cellulose products from the mold. This can be the same (disc) pin used for pre-pressing.

[0040] According to another embodiment, the web material is press-formed at a temperature of 80 °C to 180 °C. This allows the web material to be deformed to a particularly high degree, resulting in exceptionally high strength of the cellulose product. Furthermore, press-forming at these temperatures is advantageous for creating a barrier layer of barrier tissue and / or barrier film. Preferably, the web material is press-formed at a temperature of 140 °C to 150 °C.

[0041] According to another embodiment, when the cellulose products are die-cut from the web material, the connecting areas are separated from the contours of the cellulose products. This detaches the cellulose products from the rest of the web material during the die-cutting process. According to yet another embodiment, the third processing station has a centering device for high-precision die-cutting with a cutting blade that has an internal shape which is a positive replica of the external three-dimensional shape of the cellulose product.

[0042] In another embodiment, the cellulose products are heated after die-cutting using a curing device. This improves the barrier properties of the three-dimensional cellulose products. In another embodiment, the cellulose products are heated between two heated plates. In yet another embodiment, the cellulose products are heated using an infrared heater.

[0043] According to another design, a first press exerts a pressure of approximately 1 to 50 tons on a table surface of 800 x 800 mm during pre-cutting. 2 According to another embodiment, the first press exerts a pressure of 501.

[0044] According to another embodiment, a second press exerts pressure during the pressing process, based on a table surface of 800 x 800 mm. 2from approximately 1 to 5001. According to another version, the second press exerts a pressure of 500 t.

[0045] According to another embodiment, a third press exerts pressure on a table surface of 800 x 800 mm during the die-cutting process. 2 from 1 to 501. According to another version, the third press exerts a pressure of 50 t.

[0046] In another design, the web material is transported through the processing stations by means of a chain or clamp / clip guide. This enables the transport of the web material with particularly low plant engineering requirements.

[0047] According to another embodiment, the die-cut grid remaining after the cellulose products have been punched out of the web material is recycled, preferably by being fed back into the production of the web material. The invention is explained in more detail below with reference to the accompanying drawings of an exemplary embodiment. The drawings show:

[0048] Fig. 1 shows a plant for the production of a railway material in a roughly schematic view;

[0049] Fig. 2a, b shows the web material between lateral chain guides with pre-cut, press-formed and punched sections and a press tool in a second processing station in the closed state (Fig. 2a) and in the open state (Fig. 2b); Fig. 3 shows the cellulose products and the punched grid of the web material behind the third processing station in a rough schematic view; Fig. 4 shows a section of the web material during pre-pressing and pre-cutting along the contours of the cellulose products to be press-formed in a schematic sectional view.

[0050] According to Fig. 1, a plant for producing a web-shaped nonwoven fabric (nonwoven fabric plant 1) comprises two hammer mills 2, 3 in which raw material is crushed.

[0051] Furthermore, the nonwoven fabric plant 1 includes a horizontally oriented vacuum conveyor belt 4. This belt comprises an air-permeable vacuum belt 5 (screen belt) which is guided over rollers 6, 7 and has an upper run 8 and a lower run 9. One of the rollers 6, 7 is driven by a drive motor.

[0052] In the transport direction of the upper run of the vacuum conveyor belt 4, which runs from left to right in Fig. 1, four forming stations 10, 11, 12, 13 are arranged one after the other. Each of these has a forming head 14, 15, 16, 17 above the upper run 8. Below the upper run 7, the forming stations 10, 11, 12, 13 have extraction devices 18, 19, 20, 21, which are connected to a fan.

[0053] The hammer mills are connected to the forming heads 14, 15, 16, 17 via pipelines 22, 23. The pipelines 22, 23 have pneumatic transport systems for conveying the crushed raw materials to the forming heads 14, 15, 16, 17. Heated rollers 24, 25 of a compactor 26 are arranged in the transport direction of the vacuum conveyor belt 4 behind the forming stations 10, 11, 12, 13.

[0054] A layer of barrier fabric 26.2 is fed to the upper run 8 of the vacuum conveyor belt 4 from a rotatably mounted bearing roller 26.1. The bearing roller 26.1 is arranged to the left of the vacuum conveyor belt 6 in Fig. 1.

[0055] The hammer mills 2, 3 are supplied with pulp and, if necessary, starch (in powder form) and, if necessary, one or more additives as raw material.

[0056] In the hammer mills 2 and 3, the supplied materials are crushed and mixed. The materials are then conveyed through the pipelines 22 and 23 to the forming heads 14, 15, 16, and 17.

[0057] Four layers 27, 28, 29, 30 of the shredded raw material are successively applied to the barrier fabric 26.2 on the upper run 8 via the forming heads 14, 15, 16, 17 and drawn in by the vacuum applied to the underside of the upper run 8. Downstream of the forming heads 14, 15, 16, 17, the material deposited on the upper run 8 is compacted by the rollers 24, 25 of the compactor 26. Downstream of the vacuum conveyor belt 4, the compacted web-like nonwoven fabric 31 (web material), which comprises the barrier fabric 26.2 and the layers 27, 28, 29, 30 of shredded raw material, is wound into a roll.

[0058] Fig. 2 shows a section of the web material 31 unwound from the roll, which is transported by means of two laterally acting chain guides 32, 33. The transport direction in Fig. 2 is from right to left. The first section 31.1 of the web material 31 in the transport direction has not yet been processed.

[0059] The second section 31.2, preceding the first in the transport direction, is located in a first processing station 34, where contours 35 of cellulose products and contours 36 of connection areas, which connect the contours 35 to the remaining web material 31, are pre-cut in the web material 31 by means of a pre-cutting device. The contours 35 of the cellulose products are circular. The contours 36 of the connection areas are strip-shaped and have a zigzag pattern. The first processing station 34 has a pre-cutting device in the form of a first press with cutting blades. The pre-cutting device is not shown for clarity.

[0060] In the third section 31.3 of the web material 31, which precedes it in the transport direction, the cellulose products 37 are press-molded in a second processing station 38. The second processing station 38 has a forming tool 39 in the form of a second press with a positive and a negative tool part 40, 41, which correspond to the inner and outer contours of the cellulose products 37. According to Fig. 2, the cellulose products 37 are shells. Preferably, the barrier fabric 26.2 covers the inner surfaces of the shells.

[0061] During compression molding, the diameter of the circular contours 35 at the upper edges of the cellulose products decreases, creating spaces 42 between these contours 35 and the adjacent areas of the web material 31. These spaces form the connection areas 43, which are shown in Fig. 2b. The upper edges of the compression-molded cellulose products 37 are connected to the inner edges of the remaining web material 31 via the connection areas 43. Due to their zigzag shape, the strip-shaped connection areas 43 are slightly pulled apart. The connection areas 43 hold the compression-molded cellulose products 37 in place during further transport of the web material 31.

[0062] The forming tool 39 has a (disc) pin for pre-pressing the three-dimensional shape of the cellulose products 37 into the web material 31 and for pressing the cellulose products 37 out of the forming tool 39 after compression molding. These are not shown for clarity.

[0063] The fourth section 31.4 of the web material 31, which precedes it in the transport direction, is located in a third processing station 44, in which a device for punching out the press-molded cellulose products 35 from the web material 31 is provided. The punching device is a third press that has corresponding punching dies. The punching die of the punching device preferably has an internal positive image of the three-dimensional shape of the cellulose product 35 so that it can be punched out with an accuracy of up to 1 / 10 mm. The punching device is not shown for the sake of clarity.

[0064] In Fig. 2a, the press-molded cellulose products 37 are still connected to the rest of the web material 31 via the connecting areas 49. In Fig. 2b, the connecting areas 43 are cut and the cellulose products 37 are separated from the rest of the web material 31, which is referred to as the die-cut grid 45.

[0065] The punch grid 45 is recycled by feeding it, together with the raw material, to the hammer mills 2, 3.

[0066] The stacked cellulose products 37 and the recycling of the die-cut grid 45 are shown in Fig.

[0067] 3 shown.

[0068] According to the embodiment shown in Fig. 4, in the embodiment shown in Fig.

[0069] 2 The second section 31.2 of the web material is pre-pressed at the contour 35 of a pressable cellulose product 37 in the first processing station 34 by means of a pre-pressing device 46 and simultaneously pre-cut by means of a pre-cutting device 47. The pre-pressing device 46 comprises a press tool 48 with an upper tool 48.1 and a lower tool 48.2, which are pressed from different sides against the contour 35 of the pressable cellulose product and the adjacent edge regions of the web material 31. In the case of the shell-shaped cellulose product 37 according to Fig. 2, the upper tool 48.1 and the lower tool 48.2 are each annular with a rectangular cross-section.

[0070] Furthermore, the pre-pressing device 46 in the upper tool 48.1 has a slot 49 that runs along the contour 35 or sections of the contour 35 perpendicular to the surface of the web material and in which at least one hollow cylindrical cutting blade 50 is guided, the cutting blade being connected at its upper end to a cutting drive. The cutting blade 50 has projecting cutting edges 51 at its lower end, which are designed to cut through a section of the contour 35 of the cellulose product 37 to be press-molded. In the production of the cellulose products 37, the contours and the adjacent edge areas are pre-pressed and the contours 35 are pre-cut in the first processing station 34. Pre-pressing stabilizes the cut edges, reduces dust generation during cutting, and strengthens the uncut connection areas within the contours.

[0071] Pre-pressing, pre-cutting, pressing, and die-cutting of the cellulose products 37 result in short cycle times, high throughput, and simple tools with long service life and low downtime. Pre-pressing, pre-cutting, and pre-pressing enable the production of particularly deep cellulose products 37. Reference numeral list

[0072] nonwovens plant

[0073] , 3 Hammermühle

[0074] Vacuum conveyor belt

[0075] air-permeable vacuum tape

[0076] 7 rolls

[0077] Obertrum

[0078] Untertrum

[0079] 0-13 Forming station

[0080] 4-17 Forming head

[0081] 8-21 From suction device

[0082] 2, 23 Pipeline

[0083] 4.25 heated roller

[0084] 6 Compact

[0085] 6.1 Bearing roller

[0086] 6.2 Barrier tissue

[0087] 7-30 Position of the crushed raw material

[0088] 1. Railway material

[0089] 1.1 first section

[0090] 1.2 second section

[0091] 1.3 third section

[0092] 1.4 fourth section

[0093] 2.33 Chain guide

[0094] 4 first processing station

[0095] 5 Outline of a cellulose product

[0096] 6. Contour of a connection area

[0097] 7 Cellulose product

[0098] 8 second processing station

[0099] 9 Forming tool

[0100] 0 positive tool part

[0101] 1 negative tool part

[0102] 2 Free space

[0103] 3 Connection area third processing station punch grid

[0104] Pre-pressing device Pre-cutting device Pressing tool Upper tool Lower tool

[0105] slot

[0106] Cutting blade

[0107] Cutting edge

Claims

Claims:

1. Method for producing three-dimensional cellulose products, comprising the following steps: • Providing a web material (31) which is a web-shaped nonwoven fabric based on cellulose fibers, • Transporting the railway material (31) through successive processing stations (34, 38, 44), • Pre-cutting contours (35) of the cellulose products (37) in the web material (31) in a first processing station (34), • Pressing the cellulose products (37) within the pre-cut contours (35) in the web material (31) in a second processing station (38), • Punching out the press-molded cellulose products (37) from the web material (31) in a third processing station (44), wherein the cellulose products are not filled before punching out if they are designed as containers for filling with goods.

2. Method according to claim 1, wherein the web material (31) is pre-pressed in the areas where the contours (35) are pre-cut before pre-cutting or pre-cutting the contours of the cellulose products (37), and is not pre-pressed or is pre-pressed to a small extent in the areas where the cellulose products are press-molded.

3. Method according to claim 2, wherein the initial thickness of the web material (31) is at least 1 cm and / or the wall thickness of the compression-molded cellulose product (37) is at least 1 mm and / or the material thickness of the pre-pressed areas is less than 1 mm.

4. Method according to claim 3, wherein the initial thickness of the web material (31) is 2 to 4 cm and / or the wall thickness is 2 to 5 mm and / or the material thickness of the pre-pressed areas is 0.1 to 0.8 mm.

5. Method according to any one of claims 1 to 4, wherein the web material (37) comprises several superimposed layers (27 to 30) of nonwoven fabric and / or wherein the web material has a barrier fabric (26.2) and / or a barrier film and / or another barrier layer on one side or on both sides.

6. Method according to any one of claims 1 to 5, wherein the web material (31) comprises starch, thermoplastic fibers and / or another additive which contributes to strengthening the cellulose products.

7. Method according to any one of claims 1 to 6, wherein the web material (31) comprises at least one layer (27 to 30) consisting substantially or exclusively of cellulose fibers.

8. Method according to any one of claims 1 to 7, wherein the web material (31) is produced by dry depositing one or more layers (27 to 30) containing cellulose fibers onto a vacuum conveyor belt (4), suctioning the at least one layer onto the top of the vacuum conveyor belt and compacting the at least one layer between at least one roller (24, 25) and the vacuum conveyor belt (4) or another substrate.

9. Method according to any one of claims 1 to 8, wherein the web material (31) is provided as roll material.

10. Method according to any one of claims 5 to 9, wherein the web material (31) is provided on at least one side with a layer of a barrier fabric or barrier film or other barrier layer during transport to the first processing station (34).

11. Method according to any one of claims 1 to 10, wherein the web material (31) is provided in a dry state and / or wherein the web material (31) is moistened before processing in at least one processing station.

12. Method according to one of claims 1 to 11, wherein, during the pre-cutting of the contours (35) of the cellulose products (37) in the first processing station (34) The connecting areas (43) which connect the pre-cut contours (35) with the remaining web material (31) are not cut through until the cellulose products are punched out in the third processing station (44).

13. Method according to any one of claims 1 to 12, comprising one or more of the following features: • In the first processing station (34) only sections of the contours (35) of the cellulose products (37) are pre-cut, so that connecting areas (43) are present between adjacent pre-cut sections of the contours of the cellulose products and the remaining web material, • the connecting areas (43) are strip-shaped, • the strip-shaped connecting areas (43) have a zigzag pattern in the web material (31), • the connection areas (43) are evenly distributed over the circumference of the contours (35) of the cellulose products (37), • the web material (31) is only partially cut perpendicular to its main expansion surface in the area of ​​the contours of the cellulose products (37) during pre-cutting.

14. Method according to any one of claims 1 to 13, wherein the web material (31) is lightly pre-pressed into a three-dimensional shape within the pre-cut contours (35) in the second processing station (38) by means of a (disc) pin and subsequently the three-dimensional cellulose products (37) are pressed between a positive and a negative tool part (40, 41) of the forming tool (39) and / or wherein the cellulose products (37) are pushed out of the positive and / or the negative tool part (40, 41) of the forming tool (39) after compression forming by means of a (disc) pin.

15. Method according to one of claims 1 to 14, wherein the web material (31) is pressed in the second processing station (38) within the pre-cut contours (35) between a positive and a negative tool part (40, 41) of the forming tool (39), wherein the negative tool part (41) is subjected to a vacuum.

16. Method according to any one of claims 1 to 15, wherein the third processing station (44) has a device for punching with a punching knife which has an internal shape that is a positive image of the external three-dimensional shape of the cellulose product (37).

17. Method according to any one of claims 1 to 16, comprising one or more of the following features: • the web material (31) is press-molded at a temperature of 80° to 180°C, • the barrier layers of the cellulose products (37) are heat-treated after die-cutting in a curing device by means of a heating device, • A first press exerts a pressure of approximately 1 to 50 tons during pre-cutting, based on a table surface of 800 x 800 mm. 2 out of, • A second press exerts a pressure of approximately 1 to 5001 during the pressing process, based on a table surface of 800 x 800 mm. 2 out of, • A third press exerts a pressure of approximately 1 to 50 t during the die-cutting process, based on a table area of ​​800 x 800 m2, • When the cellulose products (37) are punched out of the web material (31), the connecting areas (43) are separated from the contours (35) of the cellulose products (37), • the web material (31) is transported through the processing stations (34, 38, 44) by means of a chain or clamp Z-clamp guide, • After the cellulose products (37) have been punched out of the web material (31), the remaining die-cutting grid (45) is recycled, preferably by being fed back into the production of the web material (31).

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