A method for producing a cellulose product and a cellulose product

Abstract

A High Density Dry Moulded Fibre (HD-DMF) cellulose product (1) comprising a tube-shaped member (8) and a method and system for producing such a cellulose product (1) from a cellulose paper material (2), where the forming mould (3) comprises a first mould part (4) having an inner surface (13), a second mould part (5) having a rotatable shaft (9) having an outer surface (16), and a third mould part (6) having a tube-shaped pressing member (10), wherein the method comprises the steps of; arranging the cellulose paper material (2) on the rotatable shaft (9) by rotating the rotatable shaft (9), thereby winding a predefined number of layers of cellulose paper material (2) onto the rotatable shaft (9); arranging the rotatable shaft (9) with the cellulose paper material (2) in the first mould part (4), thereby creating a tube shaped forming space (11) between the inner side wall (13) of the first mould part (4) and the outer surface (16) of the rotatable shaft (9); and forming the cellulose product (1) by pressing the cellulose paper material (2) with the tube-shaped pressing member (10) with a forming pressure to obtain the cellulose product (1).

Description

[0001] A METHOD FOR PRODUCING A CELLULOSE PRODUCT AND A

[0002] CELLULOSE PRODUCT

[0003] TECHNICAL FIELD

[0004] The present disclosure relates to a method for producing a high density dry moulded fibre (HD-DMF) cellulose product comprising a tube-shaped member from a cellulose paper material comprising cellulose fibres.

[0005] BACKGROUND

[0006] Cellulose fibres are often used as raw material for producing or manufacturing various products. Products formed of cellulose fibres can be used in many different situations where there is a need for having sustainable products of essentially non-flat shapes. An essentially non-flat shapes may refer to any suitable three-dimensional object shape. There is a wide range of products that can be produced from cellulose fibres and a few examples are disposable plates and cups, blank structures and packaging materials. Packages produced from cellulose fibres may for example be used for packaging of liquids, dry materials and other types of goods, where the packaging may be made in a three-dimensional shape or formed into a three-dimensional shape from a two-dimensional sheet material. Such products are often laminated with different films in order for the product to withstand liquids, grease, heat etc.

[0007] Cellulose fibres are obtained by separating the cellulose fibres from a pulp derived from e.g. wood or other plants. Pulp is a lignocellulosic fibrous material that can be prepared either mechanically or chemically by separating cellulose fibres from wood or other plants. Wood pulp is e.g. obtained by grinding timber or trees in some kind of mill, e.g. a disc refiner, where the wood is ground to wood pulp. The pulp contains water, cellulose fibres, lignin and hemicelluloses. For some products, e.g. where the strength is not a key factor and / or when a low price is important, a lignocellulosic material, i.e. fibres where the lignin is not removed, can be used. There are different processes that can separate wood fibres. When preparing mechanical pulp, thermomechanical pulp or chemo-thermomechanical pulp, the fibres are separated but the lignin is not removed from the cellulose fibres. In a chemical pulp process, the lignin and some of the hemicelluloses is removed more or less completely from the pulp, leaving substantially pure cellulose fibres.

[0008] One material commonly used for cellulose fibre products is wet moulded pulp. The pulp used for wet forming is often obtained from recycled paper boards and newspaper, where the cellulose fibres comprise lignin. This lowers the cost. Wet moulded pulp has the advantage of being considered as a sustainable packaging material, since it is produced from biomaterials and can often be recycled or composted after use. Consequently, wet moulded pulp has been quickly increasing in popularity for different applications. Wet moulded pulp articles are generally formed by immersing a suction mould into a liquid or semi liquid pulp suspension or slurry, while suction is applied, whereby a body of pulp is formed with the shape of the desired product by fibre deposition. The suction mould is then withdrawn from the suspension and the suction is generally continued to compact the deposited fibres while exhausting residual liquid. With all wet-forming techniques there is a need for drying of the wet moulded product, where the drying is a very time and energy consuming part of the production, which is costly. Further, this method requires a large quantity of water. The demands on aesthetical, chemical and mechanical properties of products are increasing, and due to the properties of wet-formed cellulose products, the mechanical strength, flexibility, and chemical properties are limited. It is also difficult in the wet-forming process to control the mechanical properties of the products with high precision.

[0009] Another known method for producing products from cellulose material is by pressing loose cellulose fibres in a dry state, known as Dry Moulded Fibres (DMF). These products can be made in a cost-efficient way without using water as a cellulose fibre bearer and with a reduced energy need. Such products can be used to replace disposable plastic products, but are somewhat limited when it comes to strength and the possibility to vary the thickness of a product to a great extent. A Dry Moulded Fibres product is produced from an air-laid cellulose fibre structure where the cellulose fibre structure is pressed in a forming mould to a three-dimensional cellulose product.

[0010] In a DMF process, cellulose fibres are formed with a forming pressure between 10-20 MPa in a regular compression mould. In such forming, the cellulose fibres arranged in a cellulose fluff blank are drawn apart somewhat when a non-flat shape is created. If the shape or height difference is too large, the cellulose blank may be torn, which is one reason why deep drawn dry moulded fibre products are difficult to produce. Since the cellulose blank does not float or stretch, it is also difficult to produce dry moulded cellulose products where the difference in thickness varies over the cellulose product. DMF products can be produced at the same cost as disposable plastic products.

[0011] There is thus a need for improved sustainable cellulose products, where the cellulose products are having improved mechanical and chemical properties, can be manufactured with high precision, and where the production is costefficient and rational.

[0012] SUMMARY

[0013] An object of the present disclosure is to provide a method for producing a cellulose product comprising a tube-shaped member where the previously mentioned problems are avoided. This object is at least partly achieved by the features of the independent claim. The dependent claims contain further developments of the method for producing a cellulose product comprising a tube-shaped member. Another object of the present disclosure is to provide a cellulose product forming mould. Another object of the present disclosure is to provide a cellulose product forming system. Another object of the present disclosure is to provide a cellulose product comprising a tube-shaped member. The disclosure concerns a method for producing a High Density Dry Moulded Fibre cellulose product comprising a tube-shaped member from a cellulose paper material, where the forming mould comprises a first mould part, a second mould part and a third mould part, where the first mould part comprises an inner side wall, where the second mould part comprises a rotatable shaft, and where the third mould part comprises a tube-shaped pressing member arranged concentrical with the rotatable shaft of the second mould part, wherein the method comprises the steps of; arranging the cellulose paper material on the rotatable shaft of the second mould part by rotating the rotatable shaft, thereby winding a predefined number of layers of cellulose paper material onto the rotatable shaft, arranging the rotatable shaft with the cellulose paper material in the first mould part, thereby creating a tube-shaped forming space formed between the inner side wall of the first mould part and the outer surface of the rotatable shaft;

[0014] ; and forming the cellulose product from the cellulose paper material in the forming mould, by pressing the cellulose paper material in a pressing action with the tube-shaped pressing member of the third mould part with a forming pressure to obtain the tube-shaped cellulose product.

[0015] One advantage of the method is that the tube-shaped pressing member has a relatively small pressing surface that enables transformation of a pressing force from a relatively small press of e.g. 1-2 tons to a very high forming pressure.

[0016] According to one example, the forming pressure is at least 100 MPa.

[0017] According to one example, the forming pressure is at least 200 MPa. According to one example, the tube-shaped forming space is obtained between an inner side wall of the of the first mould part and an outer surface of the rotatable shaft of the second mould part. The cellulose paper material is pressed between a pressing surface of the third mould part and a bearing surface of the forming mould in the tube-shaped forming space.

[0018] According to one example, the pressing of the cellulose material includes rotating and / or vibrating the first mould part and / or the second mould part and / or the third mould part of the forming mould during the pressing action.

[0019] According to one example, the rotation and / or vibration of the first mould part and / or the second mould part and / or the third mould part takes place during the closing stroke of the pressing action. Other relative movements are possible, e.g. ultrasonic vibration of the shaft in the longitudinal, the transverse and / or the rotational direction. The advantage of the relative motion is that the cellulose material is subjected to shear stress that causes the cellulose material to assume liquid-like properties that allows for the cellulose material to flow into and conform to the mould shape.

[0020] According to one example, the temperature of the cellulose material 2 is controlled to a predefined temperature during the pressing action, wherein the predefined temperature is in the range of 50-300 °C.

[0021] According to one example, the cellulose paper material is attached to the rotatable shaft by a gripping means before the cellulose paper material is arranged on the rotatable shaft.

[0022] According to one example, the cellulose paper material is supplied from a roll of paper and where the cellulose paper material is cut to a pre-defined length when the winding of the cellulose paper material is completed. According to one example, the shape of the tube-shaped forming space and the tube-shaped pressing member is circular. Other forms and shapes than circular is also possible in order to create non-circular cellulose products.

[0023] According to one example, the cellulose material contains less than 20% water by weight. Preferably, the cellulose material contains between 8-12% water by weight.

[0024] According to one example, the cellulose material comprises at least 90% cellulose fibres by dry weight. It should be noted that the remaining 10% is free from environmentally hazardous substances and compounds.

[0025] According to one example, the cellulose material comprises cellulose fibres and at least one additive. The additive is not intended to act as a binder between the fibres since it contradicts the idea of dry moulding the fibres. The process of dry moulding fibres relies on the forming of hydrogen bonds between the fibres.

[0026] The invention also relates to a cellulose product forming mould for dry-forming a High Density Dry Moulded Fibre cellulose product comprising a tube-shaped member from a cellulose paper material, wherein the product forming mould comprises a first mould part, a second mould part and a third mould part, where the first mould part comprises an inner side wall cavity, where the second mould part comprises a rotatable shaft, and where the third mould part comprises a tube-shaped pressing member, wherein the rotatable shaft of the second mould part comprises a gripping means configured to grip the cellulose paper material, where the rotatable shaft is configured to be rotated by a predefined number of rotations, such that a number of layers of cellulose paper material is arranged on the rotatable shaft; that the rotatable shaft with cellulose paper material is configured to be arranged in the first mould part, thereby creating a tube-shaped forming space between the inner side wall of the first mould part and the outer surface of the rotatable shaft; and that the forming mould is configured to press cellulose paper material arranged in the tube-shaped forming space between a pressing surface of the tube-shaped pressing member and a bearing surface of the forming mould with a forming pressure to obtain the cellulose product.

[0027] According to one example, the rotatable shaft is configured to rotate in a first direction when cellulose paper material is wound onto the rotatable shaft, and in an opposite direction when the cellulose paper material is arranged in the tube-shaped forming space.

[0028] The invention also relates to a cellulose product forming system, wherein the cellulose product forming system comprises a product forming mould and a paper supply device, where the paper supply device comprises a first pair of rollers configured to feed cellulose paper material from a paper roll and a second pair of rollers configured to feed cellulose paper material to the rotatable shaft.

[0029] According to one example, the paper supply device comprises a first cutting device configured to cut the cellulose paper material to a pre-defined length when the winding of the cellulose paper material onto the rotatable shaft is completed.

[0030] According to one example, the cellulose product forming system comprises a plurality of product forming moulds and a plurality of paper supply devices.

[0031] According to one example, the cellulose product forming system comprises a paper roll holder configured to hold a roll of cellulose paper material and a plurality of second cutting devices configured to cut the roll of cellulose paper material into a plurality of cellulose paper material strips.

[0032] The invention also relates to a High Density Dry Moulded Fibre cellulose product comprising a tube-shaped member formed from a cellulose paper material, wherein the cellulose product has a density greater than 1 ,30 g / cm3 According to one example, the cellulose product has a smooth inner surface, i.e. inner wall surface, and / or a smooth outer surface, i.e. outer wall surface. According to one example, the cellulose product has a threaded inner surface and / or a threaded outer surface. Hence, the method and apparatus according to the invention can be configured to manufacture various kind of products with high density and thus great properties and performance comparable to similar plastic products.

[0033] According to one example, the cellulose product has a wall thickness that varies with at least 200%.

[0034] According to one example, the cellulose product comprises a lower end portion, an upper end portion and a side wall having an outer wall surface and an inner wall surface, where the outer wall surface and / or the inner wall surface is provided with at least one protruding element. Here, the shaft outer surface comprises indentations corresponding to the protruding element of the inner wall surface of the cellulose product. In another example, the outer wall surface of the cellulose product is provided with at least one protruding element and, in a similar manner as the shaft outer surface comprises indentations in the example above, the inner side wall of the first mould part comprises indentations corresponding to the protruding elements in the outer wall surface. In one example the outer wall surface and the inner wall surface comprises protruding elements, and then the inner side wall comprises indentations and the shaft outer surface comprises indentations correspondingly.

[0035] According to one example, the lower end portion and / or the upper end portion of the cellulose product is provided with at least one protruding element. When the lower end portion is provided with at least one protruding element, then the bearing surface comprises corresponding indentations. When the upper end portion is provided with at least one protruding element, then the pressing surface of the pressing member comprises corresponding indentations. When the lower end portion is provided with at least one protruding element and the upper end portion is provided with at least one protruding element, then the bearing surface comprises corresponding indentations and the pressing surface of the pressing member comprises corresponding indentations.

[0036] The cellulose paper material comprises at least 50% cellulose fibres. The material may e.g. be wood fibres comprising some lignin and hemicellulose, or may comprise cellulose fibres and some additives.

[0037] Advantages with these features are that the method provides an efficient manufacturing process for cellulose products with improved mechanical and chemical properties, where a cellulose product is a high density dry moulded fibre (HD-DMF) product. The advantage with this method is that high density dry moulded fibre products are provided, having a higher strength than regular dry moulded fibre (DMF) products that are moulded with a forming pressure in a range between 10-30 MPa. The forming pressure is greater than 100 MPa, preferably greater than 150 MPa, and preferably greater than 200 MPa or more.

[0038] With a sufficiently high forming pressure and with a possible rotational and / or vibrating movement, the cellulose material will flow in the forming mould. In this way, cellulose products having more complicated shapes that are not possible to obtain by regular dry moulded fibres forming can be produced. It is e.g. possible to provide cellulose products having a wall thickness that varies with more than 200%. One example of such a cellulose product is a screw cap for a beverage bottle, where the cap comprises an internal thread adapted to interact with a thread of a bottle neck. Other closure parts are also possible to produce. Another product suitable to produce with the inventive method is a coffee capsule, where the coffee capsule is deep drawn. Due to the flow of the cellulose material, a thin, deep cellulose capsule can be obtained. The inventive method further allows for cellulose products having sections with different thicknesses, such that the rim of the capsule may be thicker than the side wall, and such that the bottom of the capsule may comprise thinner sections that are easier to penetrate. In a screw cap, the thickness of a threaded section is around twice as a non-threaded section.

[0039] A further advantage of the inventive method is that the forming mould must not be filled evenly with cellulose material before the pressing action, as is the case with the regular dry moulded fibres method. Due to the shear forces acting on the cellulose material during the pressing action, the cellulose material will flow into all regions of the forming mould, filling the forming mould evenly with cellulose material. In the shown example, a cellulose paper material is arranged as a tube-shaped cellulose pre-form made from a roll of thin paper, where several layers of cellulose paper material is wound on a rotatable shaft prior to pressing. It is important that the correct amount of cellulose material is used when a forming mould having a predefined volume is used, but the exact positioning of the cellulose material is not very important with the inventive method.

[0040] The moulding of a HD-DMF product is in one example performed in a closed mould having a predefined volume, where the cellulose material is completely enclosed by the mould. During a moulding action with a high forming pressure, where the forming pressure exceeds 100 MPa, the forces acting on the cellulose fibres will not only provide a compressing force but also a shear force on the cellulose fibres when a three-dimensional product is moulded, since the cellulose fibres will be displaced somewhat. The shear forces acting on the cellulose fibres will to some extent transform some of the cellulose fibres to micro fibrils and nano-cellulose. This process will be accelerated by introducing shear forces to the cellulose material through rotation and / or vibration of one or more of the forming mould parts relative to other forming mould parts during the pressing action. The high pressure and the rotational and / or vibration movement will allow the cellulose material to flow and to fill the forming mould completely. In this way, relatively complicated circular or non-circular cellulose products can be obtained. By rotating and / or vibrating one or more of the forming mould parts, the cellulose material in the forming mould will be exposed to shear forces that allows the cellulose fibres to flow.

[0041] In one example, the forming pressure is higher than 150 MPa and may be higher than 200 MPa or higher, depending on the produced cellulose product. The forming pressure may be up to 500 MPa or even up to 1000 MPa or more, depending on the intended use and the actual cellulose product. If various additives are used in the cellulose material, this may also impact the most suitable forming pressure. The density of the moulded cellulose product is greater than 1 ,30 g / cm3and may be up to 1 ,40 g / cm3or even higher. Tests have shown that a density of a moulded cellulose product greater than 1 ,40 g / cm3or more is possible to achieve, and densities can come close to the upper limit of 1 .6 g / cm3for crystalline cellulose.

[0042] A higher forming pressure will give a cellulose product with a higher strength and a higher density. By exposing the cellulose material to shear forces by rotating and / or vibrating one or more of the forming mould parts during the pressing action, a cellulose product having the same properties can be achieved with a reduced forming pressure.

[0043] The rotation and / or vibration of a forming mould part is performed during the pressing action by rotating and / or vibrating one of the forming mould parts with e.g. a hydraulic or electrical rotational device. The rotational or vibration device may be integrated directly with the forming mould part, or may be arranged outside of the forming mould part, at the holder plate for the forming mould part.

[0044] The degree of rotation is in one example at least 60 degrees, and may be up to 720 degrees or more. The rotational speed is relatively low, and may e.g. be between 1 -120 rpm. The rotation may be performed during the closing stroke of the forming mould and / or when the forming mould is completely closed, such that the rotation is performed when the forming pressure is high. The rotation device may be a mechanical, a servo-hydraulic, an electrohydraulic or an electrical rotation device. It is also possible to rotate one of the forming mould parts continuously with a rotating motor. In this way, the rotation does not have to start and stop during a pressing action.

[0045] In one example, one part of the forming mould is rotated in a first rotational direction during the pressing action. This would e.g. be suitable when producing a screw cap having an internal thread. By rotating the forming mould a few degrees in a second rotational direction when the forming mould is opened, the screw cap will be released some from the first forming mould part, such that the screw cap is easier to release completely from the first forming mould part when the forming mould has returned to the initial position.

[0046] The vibrations introduced to the forming mould are in one example created by a vibration device integrated in one of the mould parts of the forming mould. The vibration device may be integrated directly into the forming mould part, may be positioned in the holder plate for the forming mould part or may be arranged at the forming press, e.g. by controlling the hydraulic press cylinder. By positioning the vibration device in the holder plate or at the forming press, the same vibration device can be used for different forming moulds, where a forming mould part is attached to the holder plate. A further advantage of positioning the vibration device to the holder plate or at the forming press is that the vibration device must not be exposed to the heat of the forming mould. There is an insulation between the holder plate and the forming mould. A further advantage is that forming moulds of different sizes and shapes can be attached to the same holder plate, which reduces the need for several vibration devices.

[0047] For relatively low frequency vibration, typically below 100 Hz, servo-hydraulic or electrohydraulic devices can be used. For frequencies typically between 1 Hz to 2000 Hz, electrodynamic devices can be used. In one example, the vibrations have a relatively low frequency, in the range between a few Hz up to 100 Hz. The vibrations are superimposed on the regular forming pressure, where the initial forming pressure preferably is above 100 MPa or more. The waveform of the vibrations is not crucial, and a sinusoidal waveform or a triangular waveform may be used. The stroke of the vibration device may be relatively short, from parts of a mm up to a few mm. The total energy of the vibrations is a combination of pressure, frequency and stroke length. A rotational vibration over a few degrees up to 30 degrees or more is preferred.

[0048] It is also possible to position a vibration device at the lower end of the first forming mould part such that it can act directly on the cellulose fibres, e.g. a piezo device. Such a device is capable of producing vibration frequencies of up to 20 kHz or more. The used vibration frequency and the used amplitude will depend on the size and shape of the cellulose product. A higher frequency and / or higher amplitude may e.g. be required for cellulose products having thinner side walls. The vibrations are introduced to the cellulose fibres at the same time as the rotational movement, e.g. during the closing stroke of the pressing action and / or when the forming mould is closed. The vibrations may continue during the holding time of the pressing cycle, but are shut off during the opening stroke of the pressing action. The direction of the vibrations may also vary, and may be axial, rotational, translational or a combination of these.

[0049] The high pressure and the shear forces acting on the cellulose fibres due to the rotational and / or vibrational movement allows the cellulose fibres to flow in the forming mould. This may be referred to as burst flow. After a specified holding time, which may be very low, the cellulose product is ready and can be removed from the forming mould.

[0050] The temperature of the cellulose material is preferably above 50 degrees Celsius during the pressing action. The temperature should not exceed 300 degrees Celsius. The temperature of the cellulose material is controlled to a predefined temperature during the pressing action, wherein the predefined temperature is in the range of 50-300 °C

[0051] The material used for the cellulose product preferably comprises natural cellulose fibres and may further comprise other substances. If the material is wood, the material comprises cellulose fibres, lignin and hemicellulose. The material is in one example wood pulp, a fibrous lignocellulosic material prepared from wood or other plants by chemically, semi-chemically or mechanically treatment of the material. Such a material may e.g. comprise between 50-99% cellulose fibres.

[0052] The material used may also comprise cellulose fibres and some additives, such as different barrier materials that are intended to increase the resistance of the cellulose product to withstand liquids, grease, oil, heat etc. The additives are preferably mixed into the cellulose material such that the cellulose material comprises a homogenous mixture of the different ingredients. Other additives that may be used could be additives that increase the strength of the cellulose product, or additives that increase the flowability of the material during the pressing action.

[0053] The cellulose material will also comprise some water. A water content between 2-25% may be used, depending on the actual cellulose material used. A too low water content will reduce the possibility to form hydrogen bonds between the cellulose fibres. In one example, the water content of the cellulose blank is in the range between 8-12% by weight.

[0054] It is of advantage that the forming pressure is as low as possible to obtain a cellulose product with the required properties. By rotating and / or vibrating at least one forming mould part in combination with a high forming pressure, the forming pressure can be reduced when compared to a regular axial pressing action. The rotational and / or vibrational movement will increase the shear forces between the cellulose fibres in the cellulose material. With enough shear forces acting on the cellulose fibres, the cellulose material will flow and will be able to fill the forming mould completely, even if the shape of the forming mould is relatively complicated with varying wall thickness, threads, gripping surfaces etc. This is opposed to regular dry moulded fibre forming, where an air-formed cellulose mat structure is pressed in a forming mould. In such a method, the cellulose mat structure is compacted to a cellulose product having substantially the same wall thickness and having a density below 1 ,30 g / cm3

[0055] The cellulose product may be formed in a closed mould having a specified volume, where a predefined amount of material will be inserted and pressed. This will give a cellulose product having a predefined volume, shape and density. By selecting the pressing parameters correctly, a cellulose product having a density higher than 1 ,30 g / cm3is obtained. It is important that the correct amount of material is used in such a forming mould in order to obtain a cellulose product with the desired density. With a too low material content, there will not be enough shear forces acting on the cellulose fibres. When enough material is used in the forming mould, the material will flow, which will give a cellulose product with a density of at least 1 ,30 g / cm3. More material will give a higher density, up to a maximal value, depending on the used forming pressure and the degree of rotation.

[0056] The preferred forming pressure is a forming pressure where the desired parameters for the cellulose product are met, without exceeding these parameters. A higher forming pressure adds a cost to the cellulose product. This means that in the same press with the same rated pressure, fewer and / or smaller cellulose products can be made with the same forming pressure. There is thus a need to optimize the used forming pressure to the desired properties of the cellulose product. It has been shown that a forming pressure exceeding approximately 100 MPa will allow the cellulose material to flow, which allows for a HD-DMF product having a more complicated shape and a varying thickness. By rotating and / or vibrating one or more of the forming mould parts, the used forming pressure can be reduced.

[0057] One advantage with a higher forming pressure where the cellulose material assumes liquid-like properties is that complicated shapes can be obtained, which are difficult to obtain with regular moulding of DMF products. With the inventive method, more complicated product such as a lid having internal threads and a smooth outer surface can be produced, where the wall thickness of the lid varies with up to 300-400% or more.

[0058] The cellulose product is formed in a forming mould which comprises a first mould part, a second mould part and a third mould part. The forming mould parts are non-flexible, preferably made from steel, and may be heated to the desired forming temperature. The forming mould is in one example heated with integrated heating elements, preferably electrical heating elements, but also liquid heating is possible. The forming mould is in one example provided with a closed volume, such that the density depends on the used amount of cellulose material. In another example, the forming mould is pressure controlled, such that the density depends on the forming pressure and not on the amount of cellulose material.

[0059] The cellulose material is in the shown example a cellulose paper material provided from a roll of paper. Several layers of the cellulose paper material are formed to a tube-shaped pre-form by winding the cellulose paper material onto a rotatable shaft. The roll of paper may have a width corresponding to the width of the tube-shaped pre-form. The roll of paper may also be wider than a tubeshaped pre-form, and may be cut into several strips of cellulose material by a plurality of cutting means.

[0060] During the moulding of a HD-DMF cellulose product, different forces will act on the cellulose material. By rotating and / or vibrating one or more of the forming mould parts, shear forces will act on the cellulose material. The shear forces, together with the high forming pressure, temperature and possible movements of one or more of the mould parts, will allow the cellulose fibres to flow in the forming mould.

[0061] The cellulose material may be made from mechanical pulp, thermochemical pulp or chemical pulp comprising at least some lignin and / or hemicellulose, also referred to as a lignocellulosic raw material. The cellulose material may in one example comprise more than 0,5% lignin. The cellulose material may be a lignocellulosic material comprising both lignin and hemicellulose, e.g. made from mechanical pulp. The cellulose material may also include additives, where the additives are used to decrease the liquid and / or gas permeability of the cellulose product and to increase the resistance to e.g. hot and cold liquids, grease, oil etc. Such additives may also be applied to the surface of the cellulose product after the cellulose product is formed. In one example, the cellulose material comprises at least 90% cellulose fibres by dry weight. The additives used are additives adapted to alter the permeability of the cellulose material, and should not function as a binder material to bind the cellulose material together. By using untreated cellulose fibres, the cellulose fibres are bound together by hydrogen bonds and Van der Vaals bonds. Additives may decrease the possibility for hydrogen bonds, and a binder material will definitely reduce the number of hydrogen bonds.

[0062] One suitable product made from cellulose HD-DMF is a screw cap for a bottle. The screw cap is provided with a top section and a concentric side wall having an inner surface and an outer surface, where the inner surface is provided with at least one internal thread section and where the circumferential outer surface is substantially even. Such a cellulose HD-DMF screw cap will resemble a regular plastic screw cap used for e.g. PET plastic bottles. The internal thread section may be a single thread or may comprise several thread sections that constitutes a screw thread. With the inventive method, a cellulose HD-DMF product where the thickness of the product varies with at least 200% can be obtained. A thickness variation up to 300-400% or more is possible if desired. In this way, it is possible to provide an internal thread on the inner surface of the screw cap, while the outer surface can be substantially smooth and even. It is of course also possible to provide the outer surface of the screw cap with some kind of gripping surface, a gripping rim and / or a tamper proof fixation rim. Another suitable product is a flip-lid used on containers that are not provided with a thread. Other suitable products are other types of closures comprising one or more parts. The cellulose HD-DMF product is formed in the forming mould during a cycle time period in the range of 0,1 to 10 seconds, and preferably less than 5,0 seconds. A suitable holding time for the product in the forming mould is less than a second, and may be e.g. 0,3-0, 7 seconds. The holding time together with the forming temperature, the forming pressure, humidity and the rotational movement are important parameters in the forming of the HD-DMF cellulose product.

[0063] BRIEF DESCRIPTION OF DRAWINGS

[0064] The disclosure will be described in greater detail in the following, with reference to the attached drawings, in which

[0065] Figs. 1 a-c schematically show an example of a cellulose product forming system comprising a cellulose product forming mould and a paper supply device,

[0066] Figs. 2a-b schematically show an example of a cellulose product machine comprising a plurality of cellulose product forming systems,

[0067] Figs. 3a-c schematically show a first example of a cellulose product forming mould and a cellulose product, s

[0068] Figs. 4a-c schematically show a second example of a cellulose product forming mould and a cellulose product, and

[0069] Figs. 5a-c schematically show a third example of a cellulose product forming mould and a cellulose product.

[0070] DESCRIPTION OF EXAMPLE EMBODIMENTS

[0071] Various aspects of the disclosure will hereinafter be described in conjunction with the appended drawings to illustrate and not to limit the disclosure, wherein like designations denote like elements, and variations of the described aspects are not restricted to the specifically shown embodiments, but are applicable on other variations of the disclosure. In the present detailed description, a method for producing a cellulose HD- DMF product comprising a tube-shaped member from a cellulose paper material will be described. The cellulose HD-DMF product comprises a tubeshaped member and may further comprise a flange member and / or a bottom member. The method is suitable for different products that should exhibit a higher strength and a higher density than regular DMF products, and that may have a more complicated shape with varying thickness. Such products may be relatively small with a volume of e.g. a few cm3due to the required high forming pressure, which is costly. It would of course also be possible to produce larger cellulose HD-DMF products if desired. The cellulose HD-DMF products are disposable, but may be used several times, depending on the actual product and actual post treatment of the product. The cellulose HD-DMF products may be recyclable and / or compostable.

[0072] The cellulose material used to form the cellulose HD-DMF product is a cellulose paper material comprising cellulose fibres and that may also comprise at least some lignin and hemicellulose. Such a material is produced from mechanical pulp, thermochemical pulp or chemical pulp where some of the lignin and the hemicelluloses can be removed. Additives may also be added to the cellulose material, where the additives are used to decrease the liquid and / or gas permeability of the cellulose product and to increase the resistance to e.g. hot and cold liquids, grease, oil etc. In one example, the cellulose paper material comprises at least 90% cellulose fibres by dry weight and at the most 10% lignin or additives by weight. The cellulose material may be a lignocellulosic material comprising both lignin and hemicellulose, e.g. made from mechanical pulp. The cellulose material will also comprise some water, e.g. between 6% to 25% by weight. Water is not seen as an additive, it is necessary to create hydrogen bonds between the cellulose fibres but will evaporate when the cellulose product is heated in an oven. In one example, the water content of the cellulose material is in the range between 8-12% by weight. The cellulose paper material may be positioned in a climate chamber in order to obtain the preferred water content. Water may also be sprayed onto the cellulose paper material during the winding of the cellulose paper material. The water may also contain an additive, e.g. soap.

[0073] Figs. 1 a-d show an example of a cellulose product forming system arranged to form a cellulose product comprising a tube-shaped member from a strip of cellulose paper material. The cellulose product forming system comprises a cellulose product forming mould and a paper supply device arranged to feed a paper strip to the cellulose product forming mould. In the cellulose product forming system, the strip of cellulose paper material is wound onto a rotatable shaft of the cellulose product forming mould and is then pressed in a tubeshaped forming space.

[0074] Figs. 2a-b show an example of a cellulose product forming machine comprising a plurality of cellulose product forming systems arranged side-by- side. In the cellulose product forming machine, the paper strips are cut from a roll of cellulose paper material with a plurality of cutting devices.

[0075] Figs. 3-5 show different example of a cellulose product forming mould for producing a cellulose product comprising a tube-shaped member. In the forming mould shown in Figs. 3a-b, a tube-shaped cellulose product can be produced. In the forming mould shown in Figs. 4a-b, a tube-shaped cellulose product comprising a bottom, e.g. a cup-shaped cellulose product, can be produced. In the forming mould shown in Fig. 5a-b, a tube-shaped cellulose product comprising a flange can be produced.

[0076] Figs. 3c, 4c, 5c show different example of a cellulose product. Fig. 3c shows a tube-shaped cellulose product. Fig. 4c shows a cup-shaped cellulose product. Fig. 5c shows a tube-shaped cellulose product comprising a flange.

[0077] The cellulose product forming system shown in Fig. 1 comprises a cellulose product forming mould 3 and a paper supply device 27. The cellulose product forming mould 3 comprises a first mould part 4, a second mould part 5 and a third mould part 6 corresponding to the forming mould 3 shown in Figs 3a-b. The first mould part 4 comprises an inner side wall 13 that will act as an outer pressing surface of a tube-shaped forming space 11 . The second mould part

[0078] 5 comprises a rotatable shaft 9 having an outer surface 16 that will act as an inner pressing surface of a tube-shaped forming space 11 .

[0079] The third mould part 6 comprises a tube-shaped pressing member 10 that is concentric to the rotatable shaft 9. An inner surface 19 of the third mould part

[0080] 6 will slide against the outer surface 16 of the rotatable shaft 9 and an outer surface 18 of the third mould part 6 will slide against the inner surface 13 of the first mould part 4 during a pressing action. The cellulose paper material will further be pressed between a pressing surface 17 of the third mould part 6 and a bearing surface 12 of the forming mould 3. The tube-shaped forming space 11 is created between the inner side wall 13 of the first mould part 4, the outer surface 16 of the rotatable shaft 9, the pressing surface 17 of the third mould part 6 and the bearing surface 12 of the forming mould 3.

[0081] The rotatable shaft 9 comprises a gripping means 28 that will grip the cellulose paper material 2 such that the cellulose paper material is attached to the rotatable shaft 9. The gripping means is in the shown example a plurality of vacuum holes arranged in the rotatable shaft, but any type of gripping means may be used, such has electrostatic means or adhesions of some sort. In the shown example, the cellulose paper material is a strip of cellulose paper material having a pre-defined width.

[0082] In one example, the strip of cellulose paper material 2 could also be pre-wound onto a rotatable shaft at another location, outside of the cellulose product forming mould, and could be transferred to the cellulose product forming mould in a following step. It is also possible to pre-wind the cellulose paper material in another facility which are then shipped and supplied to the system with the forming mould, where the pre-wound cellulose paper material is mounted to the rotatable shaft. When the strip of cellulose paper material is securely held onto the rotatable shaft by the gripping means, as shown in Fig. 1 b, the rotatable shaft is rotated by a pre-defined number of rotations, such that a number of layers of the strip of cellulose paper material 2 is arranged on the rotatable shaft 9. The width of the cellulose paper material, the thickness of the cellulose paper material and the number of layers determines the amount of cellulose material that will be used for the cellulose product. When the pre-determined amount of cellulose paper material is wound onto the rotatable shaft, the cellulose paper strip is cut by a first cutting means 23, as shown in Fig. 1 c. Thereafter, the rotatable shaft with the cellulose paper strip is lowered into the tube-shaped forming space 11 .

[0083] When the cellulose paper material 2 is arranged in the tube-shaped forming space 11 , the cellulose paper material 2 is pressed by the tube-shaped pressing member 10 in the forming mould 3 with a forming pressure to obtain the tube-shaped cellulose product 1 , as shown in Fig. 1 d. The forming pressure is at least 100 MPa, and may be at least 200 MPa or more. Since the tubeshaped pressing member 10 has a relatively small pressing surface, it is possible to obtain a high forming pressure in the forming mould from a relatively small pressing force, depending on the geometry of the tube-shaped forming space 11 . In one example, a relatively small press of e.g. 1 -2 tons will provide a forming pressure exceeding 200 MPa.

[0084] The cellulose paper material is preferably relatively thin and may have a thickness of e.g. 50-90 GSM or 50-100 micrometres, depending on the type of cellulose paper material used. By using a thin paper, several layers of the cellulose paper material can be wound onto the rotatable shaft, which simplifies the winding and pressing action.

[0085] The rotatable shaft 9 is configured to rotate in a first direction when a strip of cellulose paper material 2 is wound onto the rotatable shaft 9. The rotatable shaft 9 can be rotated in the same or in an opposite direction when the cellulose paper material 2 is arranged into the tube-shaped forming space 11 when the cellulose product is pressed. The rotatable shaft 9 may be rotated in only the first direction during the pressing action, or may be rotated back and forth in a vibrating manner. The rotational speed of the rotatable shaft 9 during the pressing action may be relatively slow, e.g. between 1 - 20 rpm in the first direction. It is also possible to rotate the first mould part and / or the third mould part during the pressing action.

[0086] The cellulose product forming system 30 further comprises a paper supply device 27. The paper supply device 27 will forward a cellulose paper strip 32 to the rotatable shaft 9. The cellulose paper strip 32 is in one example arranged on a cellulose paper roll held by a paper roll holder. The paper supply device 27 comprises a second pair of rollers 25 configured to feed a strip of cellulose paper material 2 from e.g. a paper roll. The paper supply device 27 further comprises a first pair of rollers 24 configured to feed the strip of cellulose paper material 2 from the second pair of rollers 25 to the rotatable shaft 9.

[0087] The first pair of rollers 24 are configured to be rotated in an intermediate manner, such that a strip of cellulose material can be fed to the rotatable shaft when it rotates. The second pair of rollers 25 are configured to be rotated in a continuous manner. In this way, a buffer 26 is created between the first pair of rollers 24 and the second pair of rollers 25. The advantage of this is that a strip of cellulose paper material 2 can be drawn from a roll of paper with a constant speed, such that the roll of paper must not be stopped and started. The roll of paper may be relatively heavy and will thus have a large moment of inertia, which cannot be stopped or started in a quick manner. The strip of cellulose paper material 2 present in the buffer can easily be controlled by the first pair of rollers 24.

[0088] When a strip of cellulose paper material 2 is wound onto the rotatable shaft 9, the strip of cellulose paper material 2 is fed to the rotatable shaft 9 by the first pair of rollers 24. The strip of cellulose paper material 2 is attached to the rotatable shaft 9 by the gripping means 28. When the strip of cellulose paper material 2 is attached to the rotatable shaft 9, the rotatable shaft 9 is rotated with a first speed to wind the strip of cellulose paper material 2 fed by the first pair of rollers onto the rotatable shaft 9. When the predefined amount of cellulose paper material 2 is arranged on the rotatable shaft 9, the strip of cellulose paper material 2 is cut with a first cutting means 23. The rotation of the rotatable shaft 9 and the feeding of the first pair of rollers is stopped during the cutting of the strip of cellulose paper material 2. When the strip of cellulose paper material 2 is cut, the feeding of the first pair of rollers is stopped and the remaining part of the strip of cellulose paper material 2 is wound onto the rotatable shaft.

[0089] The rotatable shaft 9 with the strip of cellulose paper material 2 is now inserted into the tube-shaped forming space 11 and the cellulose product is pressed by the pressing action between the pressing surface 17 of the third mould part 6 and the bearing surface 12 of the first mould part 4. During the pressing action, the first mould part 4, the second mould part 5 and / or the third mould part 6 may be moved in a rotational direction. The rotation may be in a single direction or may be back-and-forth. The temperature of the cellulose material 2 is controlled to a predefined temperature during the pressing action, wherein the predefined temperature is in the range of 50-300 °C.

[0090] The purpose of the rotational movement is to introduce shear forces to the cellulose paper material, which will allow the cellulose paper material to flow somewhat such that the cellulose paper material will fill the tube-shaped forming space completely. When the cellulose product has been formed, the rotatable shaft together with the formed cellulose product is withdrawn from the tube-shaped forming space, and the cellulose product is released from the rotatable shaft by a removal means of some sort. When the cellulose product has been released, a new product cycle starts by attaching a new strip of cellulose paper material 2 to the rotatable shaft 9.

[0091] It would also be possible to vibrate the first mould part 4, the second mould part 5 and / or the third mould part 6 in an axial and / or transverse direction during the pressing action. The amplitude of vibrations is preferably relatively small, less than a millimetre and may be around 100 micrometres or less. The frequency is relatively high, above 10 kHz. In this way, the cellulose paper material will be affected, but there is no risk that he mould parts will come in contact with each other.

[0092] Figs. 2a-b show a cellulose product machine 33 where the cellulose product machine 33 comprises a plurality of product forming systems 30. In the cellulose product machine 33, a plurality of cellulose products 1 can be formed in parallel and simultaneously. The cellulose product machine 33 comprises a paper roll holder that holds a roll 21 of cellulose paper material 2. The roll of cellulose paper material is cut to strips 32 of cellulose paper material 2 having a predefined width by second cutting means 31 arranged before the second pair of rollers 25. The strips of cellulose paper material are in the shown example turned by 90 degrees before they enter the second pair of rollers 25. A detail of the second cutting means 31 and the paper strip cutting action is shown in Fig. 2b.

[0093] Fig. 3a schematically shows an example of a cellulose product forming mould 3 for dry-forming a High Density Dry Moulded Fibre tube-shaped cellulose product 1 from a cellulose material 2, where the product forming mould 3 comprises a first mould part 4, a second mould part 5 and a third mould part 6. The first mould part 4 comprises an inner side wall 13 and in the shown example, a bearing surface 12 arranged at the bottom of the first mould part. The second mould part 5 comprises a rotatable shaft 9 having an outer surface 16. The third mould part 6 comprises a tube-shaped pressing member 10 having a pressing surface 17 arranged concentrical to the rotatable shaft 9 of the second mould part 5. A strip of cellulose material 2 is wound onto the rotatable shaft 9.

[0094] A tube-shaped forming space 11 is created between the bearing surface 12 and the inner side wall 13 of the first mould part 4, the outer side wall of the second mould part 5 and the pressing surface 17 of the third mould part 6. The tube-shaped cellulose material 2 is positioned in the tube-shaped forming space 11 by lowering the rotatable shaft 9 into the first mould part 4, such that the shaft lower end 14 of the rotatable shaft 9 will bear on the bearing surface 12 before the pressing action starts. The cellulose product is pressed by moving the pressing surface 17 towards the bearing surface 12 with a forming pressure to obtain the tube-shaped cellulose product 1 .

[0095] The forming mould 3 may be provided with one or more holes arranged to let air out of the forming mould during the pressing action, such that no air is left inside the forming mould and / or the cellulose product. Compressed trapped air may prevent a pressure gradient to form in the cellulose material during the pressing action. The holes may be smaller than the cellulose fibres, e.g. around 30-50 micrometres, such that the fibres are prevented to enter into the holes but such that air can still pass through. The holes may also be larger, e.g. 0,5 to 1 ,0 mm, such that some of the cellulose material can enter into the holes. The remains may e.g. be remove with pressurized air.

[0096] Fig. 3b shows the forming mould 3 in a closed state, where the pressing action is finalized and the tube-shaped cellulose product 1 is formed.

[0097] Fig. 3c schematically shows an example of a High Density Dry Moulded Fibre tube-shaped cellulose product 1 formed from a cellulose material 2. The density of the tube-shaped cellulose product 1 is greater than 1 ,30 g / cm3In the shown example, the tube-shaped product 1 is provided with a threaded inner surface 44. The method and apparatus according to the invention can be configured to manufacture various kind of cellulose products with a high density and thus great properties and performance comparable to similar plastic products. The wall thickness of the tube-shaped cellulose product 1 may vary with at least 200% or more.

[0098] According to one example, the tube-shaped cellulose product 1 comprises a lower end portion 40, an upper end portion 41 and a side wall 42 having an outer wall surface 43 and an inner wall surface 44, where the outer wall surface 43 and / or the inner wall surface 44 may be provided with at least one protruding element 45. The lower end portion 40 and / or the upper end portion 41 of the cellulose product 1 may also be provided with at least one protruding element of some sort, e.g. a cutting device.

[0099] Fig. 4a schematically shows an example of a cellulose product forming mould 3 for dry-forming a High Density Dry Moulded Fibre cup-shaped cellulose product 1 from a cellulose material 2, where the product forming mould 3 comprises a first mould part 4, a second mould part 5 and a third mould part 6. The first mould part 4 comprises an inner side wall 13 and in the shown example, a bearing surface 12 arranged at the bottom of the first mould part. The second mould part 5 comprises a rotatable shaft 9 having an outer surface 16. The third mould part 6 comprises a tube-shaped pressing member 10 having a pressing surface 17 arranged concentrical to the rotatable shaft 9 of the second mould part 5. A strip of cellulose material 2 is wound onto the rotatable shaft 9.

[0100] A tube-shaped forming space 11 is created between the bearing surface 12 and the inner side wall 13 of the first mould part 4, the outer side wall of the second mould part 5 and the pressing surface 17 of the third mould part 6. In the shown example, the cup-shaped cellulose product 1 comprises a tubeshaped member 8 and a bottom 46. The tube-shaped cellulose material 2 is positioned in the tube-shaped forming space 11 by lowering the rotatable shaft 9 into the first mould part 4. By positioning the shaft lower end 14 a distance above the bearing surface 12, a space for the bottom of the cup-shaped cellulose product 1 is created. The cellulose product is pressed by moving the pressing surface 17 towards the bearing surface 12 with a forming pressure to obtain the tube-shaped cellulose product 1 . The cellulose material 2 will flow into the space between the shaft lower end 14 and the bearing surface 12 such that the bottom of the cup-shaped cellulose product is obtained.

[0101] One of the advantages of this system is a lower compression force requirement due to the relatively small pressing surface 17 compared to the shaft lower end 14. However, when pressurized cellulose paper material 2 will flow into the space between the shaft lower end 14 and the bearing surface 12 to form the bottom 46, a relatively high force will act on the shaft lower end 14 and the bearing surface 12 which will push the shaft lower end 14 and the bearing surface 12 apart. This force may e.g. try to open the forming mould by pressing the second mould part 5 upwards in fig. 4b. Since it might be preferred to withdraw and maybe rotate the second mould part 5 to eject the cellulose product 1 , a self-locking device, e.g. a self-locking thread or a knee-joint clamping unit, can be used to position the shaft lower end 14 of the second mould part 5 at the defined distance above the bearing surface 12.

[0102] The forming mould 3 may be provided with one or more holes arranged to let air out of the forming mould during the pressing action, such that no air is left inside the forming mould and / or the cellulose product. Compressed trapped air may prevent a pressure gradient to form in the cellulose material during the pressing action. The holes may be smaller than the cellulose fibres, e.g. around 30-50 micrometres, such that the fibres are prevented to enter into the holes but such that air can still pass through. The holes may also be larger, e.g. 0,5 to 1 ,0 mm, such that some of the cellulose material can enter into the holes. The remains may e.g. be remove with pressurized air.

[0103] Fig. 4b shows the forming mould 3 in a closed state, where the pressing action is finalized and the cup-shaped cellulose product 1 is formed.

[0104] Fig. 4c schematically shows an example of a High Density Dry Moulded Fibre cup-shaped cellulose product 1 formed from a cellulose material 2. The density of the cup-shaped cellulose product 1 is greater than 1 ,30 g / cm3In the shown example, the cup-shaped product 1 is provided with a threaded inner surface 44. The method and apparatus according to the invention can be configured to manufacture various kind of cellulose products with a high density and thus great properties and performance comparable to similar plastic products. The wall thickness of the cup-shaped cellulose product 1 may vary with at least 200% or more. According to one example, the cup-shaped cellulose product 1 comprises a lower end portion 40 comprising a bottom 46, an upper end portion 41 and a side wall 42 having an outer wall surface 43 and an inner wall surface 44, where the outer wall surface 43 and / or the inner wall surface 44 may be provided with at least one protruding element 45. The lower end portion 40 and / or the upper end portion 41 of the cellulose product 1 may also be provided with at least one protruding element of some sort.

[0105] Fig. 5a schematically shows an example of a cellulose product forming mould 3 for dry-forming a High Density Dry Moulded Fibre tube-shaped cellulose product 1 comprising a flange from a cellulose material 2, where the product forming mould 3 comprises a first mould part 4, a second mould part 5 and a third mould part 6. The first mould part 4 comprises in the shown example a through-hole having an inner side wall 13. The first mould part 4 is further provided with a flange recess 20 which will form a flange cavity between the flange recess and a bearing surface 12 of the second mould part 5. The second mould part 5 comprises a rotatable shaft 9 having an outer surface 16. The second mould part 5 further comprises a bearing surface 12. The third mould part 6 comprises a tube-shaped pressing member 10 having a pressing surface 17 arranged concentrical to the rotatable shaft 9 of the second mould part 5. A strip of cellulose material 2 is wound onto the rotatable shaft 9.

[0106] A tube-shaped forming space 11 is created between the inner side wall 13 of the first mould part 4, the outer side wall 16 and the bearing surface 12 of the second mould part 5 and the pressing surface 17 of the third mould part 6. In the shown example, the tube-shaped cellulose product 1 comprising a flange is provided with a tube-shaped member 8 and a flange 47. The tube-shaped cellulose material 2 is positioned in the tube-shaped forming space 11 by lowering the rotatable shaft 9 into the first mould part 4. The cellulose product is pressed by moving the pressing surface 17 towards the bearing surface 12 with a forming pressure to obtain the tube-shaped cellulose product 1. The cellulose material 2 will flow into the flange cavity between the flange recess 20 and the bearing surface 12 such that the flange of the tube-shaped cellulose product comprising a flange is obtained.

[0107] The forming mould 3 may be provided with one or more holes arranged to let air out of the forming mould during the pressing action, such that no air is left inside the forming mould and / or the cellulose product. Compressed trapped air may prevent a pressure gradient to form in the cellulose material during the pressing action. The holes may be smaller than the cellulose fibres, e.g. around 30-50 micrometres, such that the fibres are prevented to enter into the holes but such that air can still pass through. The holes may also be larger, e.g. 0,5 to 1 ,0 mm, such that some of the cellulose material can enter into the holes. The remains may e.g. be remove with pressurized air.

[0108] Fig. 5b shows the forming mould 3 in a closed state, where the pressing action is finalized and the tube-shaped cellulose product comprising a flange is formed.

[0109] Fig. 5c schematically shows an example of a High Density Dry Moulded Fibre tube-shaped cellulose product 1 comprising a flange formed from a cellulose material 2. The density of the tube-shaped cellulose product 1 comprising a flange is greater than 1 ,30 g / cm3In the shown example, the tube-shaped product 1 comprising a flange is provided with a threaded outer surface 43. The method and apparatus according to the invention can be configured to manufacture various kind of cellulose products with a high density and thus great properties and performance comparable to similar plastic products. The wall thickness of the tube-shaped cellulose product 1 comprising a flange may vary with at least 200% or more.

[0110] According to one example, the tube-shaped cellulose product 1 comprising a flange comprises a lower end portion 40, an upper end portion 41 comprising a flange 47 and a side wall 42 having an outer wall surface 43 and an inner wall surface 44, where the outer wall surface 43 and / or the inner wall surface 44 may be provided with at least one protruding element 45. The lower end portion 40 and / or the upper end portion 41 of the cellulose product 1 may also be provided with at least one protruding element of some sort.

[0111] It will be appreciated that the above description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. While specific examples have been described in the specification and illustrated in the drawings, it will be understood by those of ordinary skill in the art that various changes may be made, and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure as defined in the claims. Furthermore, modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure is not limited to the particular examples illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out the teachings of the present disclosure, but that the scope of the present disclosure will include any embodiments falling within the foregoing description and the appended claims. Reference signs mentioned in the claims should not be seen as limiting the extent of the matter protected by the claims, and their sole function is to make claims easier to understand.

[0112] REFERENCE SIGNS

[0113] 1 : Cellulose product

[0114] 2: Cellulose paper material

[0115] 3: Forming mould

[0116] 4: First mould part

[0117] 5: Second mould part

[0118] 6: Third mould part

[0119] 7: Centre axis

[0120] 8: Tube-shaped member

[0121] 9: Rotatable shaft

[0122] 10: Tube-shaped pressing member

[0123] 11 : T ube-shaped form ing space

[0124] 12: Bearing surface

[0125] 13: Inner side wall

[0126] 14: Shaft lower end

[0127] 15: Shaft upper end

[0128] 16: Outer surface

[0129] 17: Pressing surface

[0130] 18: Outer surface

[0131] 19: Inner surface

[0132] 20: Flange recess

[0133] 21 : Roll of paper

[0134] 23: First cutting means

[0135] 24: First pair of rollers

[0136] 25: Second pair of rollers

[0137] 26: Buffer

[0138] 27: Paper supply device

[0139] 28: Gripping means

[0140] 30: System

[0141] 31 : Second cutting means

[0142] 32: Cellulose strip 33: Machine

[0143] 40: Lower end portion

[0144] 41 : Upper end portion

[0145] 42: Side wall 43: Outer wall surface

[0146] 44: Inner wall surface

[0147] 45: Protruding element

[0148] 46: Bottom

[0149] 47: Flange

Claims

34CLAIMS1. A method for producing a High Density Dry Moulded Fibre (HD-DMF) cellulose product (1 ) comprising a tube-shaped member (8) from a cellulose paper material (2), where the forming mould (3) comprises a first mould part (4), a second mould part (5) and a third mould part (6), where the first mould part (4) comprises an inner side wall (13), where the second mould part (5) comprises a rotatable shaft (9) having an outer surface (16), and where the third mould part (6) comprises a tube-shaped pressing member (10) arranged concentrical to the rotatable shaft (9) of the second mould part (5), wherein the method comprises the steps of; arranging the cellulose paper material (2) on the rotatable shaft (9) of the second mould part (5) by rotating the rotatable shaft (9), thereby winding a predefined number of layers of cellulose paper material (2) onto the rotatable shaft (9), arranging the rotatable shaft (9) with the cellulose paper material (2) in the first mould part (4), thereby creating a tube shaped forming space (11 ) between the inner side wall (13) of the first mould part (4) and the outer surface (16) of the rotatable shaft (9); and forming the cellulose product (1 ) from the cellulose paper material (2) in the forming mould (3), by pressing the cellulose paper material (2) in a pressing action with the tube-shaped pressing member (10) of the third mould part (6) with a forming pressure to obtain the cellulose product (1 ).

2. A method according to claim 1 , wherein the forming pressure is at least 100 MPa.

3. A method according to claim 1 or 2, wherein the forming pressure is at least 200 MPa.

4. A method according to any of claims 1 to 3,35 where the cellulose paper material (2) is pressed between a pressing surface (17) of the third mould part (6) and a bearing surface (12) of the forming mould (3) in the tube shaped forming space (11 ).

5. A method according to any of claims 1 to 4, where the pressing of the cellulose material (2) includes rotating and / or vibrating the first mould part (4) and / or the second mould part (5) and / or the third mould part (6) of the forming mould (3) during the pressing action.

6. A method according to any of the preceding claims, wherein the cellulose paper material (2) is attached to the rotatable shaft (9) by a gripping means (20) before the cellulose paper material (2) is arranged on the rotatable shaft (9).

7. A method according to any of the preceding claims, wherein the cellulose paper material (2) is supplied from a roll of paper (21 ) and where the cellulose paper material (2) is cut to a predefined length when the winding of the cellulose paper material (2) is completed.

8. A method according to any of the preceding claims, wherein the shape of the tube-shaped forming space (11 ) and the tube-shaped pressing member (10) is circular. .

9. A method according to any of the preceding claims, wherein the cellulose paper material (2) is forwarded to the rotatable shaft (9) in an intermediate manner, and wherein the cellulose paper material (2) is supplied from a roll of paper in a continuous manner, such that a buffer is created for the cellulose paper material (2).

10. A method according to any of the preceding claims,wherein the cellulose material (2) contains less than 20% water by weight.11 . A method according to any of the preceding claims, wherein the cellulose material comprises at least 90% cellulose fibres by dry weight.

12. A method according to any of the preceding claims, wherein the cellulose material comprises cellulose fibres and at least one additive.

13. A cellulose product forming mould (3) for dry-forming a High Density Dry Moulded Fibre cellulose product (1 ) comprising a tube-shaped member (8 from a cellulose paper material (2), wherein the product forming mould (3) comprises a first mould part (4), a second mould part (5) and a third mould part (6), where the first mould part (4) comprises an inner side wall (13), where the second mould part (5) comprises a rotatable shaft (9) having an outer surface (16), and where the third mould part (6) comprises a tubeshaped pressing member (10), c h a r a c t e r i z e d i n that the shaft (9) of the second mould part (5) comprises a gripping means (20) configured to grip the cellulose paper material (2), where the rotatable shaft (9) is configured to be rotated by a pre-defined number of rotations, such that a number of layers of cellulose paper material (2) is arranged on the rotatable shaft (9); that the rotatable shaft (9) with cellulose paper material (2) is configured to be arranged in the first mould part (4), thereby creating a tube shaped forming space (11 ) between the inner side wall (13) of the first mould part (4) and the outer surface (16) of the rotatable shaft (9) ; and that the forming mould (3) is configured to press cellulose paper material (2) arranged in the tube-shaped forming space (11 ) between a pressing surface (17) of the tube-shaped pressing member (10) and a bearing surface (12) of the forming mould (3) with a forming pressure to obtain the tube-shaped cellulose product (1 ).

14. A cellulose product forming mould (3) according to claim 13, wherein the rotatable shaft (9) is configured to rotate in a first direction when cellulose paper material (2) is wound onto the rotatable shaft (9), and in the same or an opposite direction when the cellulose paper material (2) is arranged in the tube-shaped forming space (11 ).

15. A cellulose product forming system (30) comprising a cellulose product forming mould (3) according to claim 13, c h a r a c t e r i z e d i n that the cellulose product forming system (30) further comprises a paper supply device (27), where the paper supply device (27) comprises a first pair of rollers (24) configured to feed cellulose paper material (2) from a paper roll (21 ) and a second pair of rollers (25) configured to feed cellulose paper material (2) to the rotatable shaft (9).

16. A cellulose product forming system (30) according to claim 15, wherein the first pair of rollers (24) are configured to be rotated in an intermediate manner, where the second pair of rollers (25) are configured to be rotated in a continuous manner, thereby creating a buffer (26) between the first pair of rollers (24) and the second pair of rollers (25).

17. A cellulose product forming system (30) according to claim 15 or 16, wherein the paper supply device (27) comprises a first cutting device (23) configured to cut the cellulose paper material (2) to a pre-defined length when the winding of the cellulose paper material (2) onto the rotatable shaft (9) is completed.

18. A cellulose product forming machine (33), wherein the cellulose product forming machine (33) comprises a plurality of cellulose product forming systems (30).3819. A cellulose product forming machine according to claim 18, wherein the cellulose product forming machine (33) comprises a roll (21 ) of cellulose paper material (2) and a plurality of second cutting devices (31 ) configured to cut the roll (21 ) of cellulose paper material (2) into a plurality of cellulose paper material strips (32).

20. A cellulose product (1 ) comprising a tube-shaped member (8) formed from a cellulose material (2), c h a r a c t e r i z e d i n that the cellulose product (1 ) has a density greater than 1 ,30 g / cm321 . A cellulose product according to claim 20, wherein a wall thickness of the cellulose product (1 ) varies with at least 200%.

22. A cellulose product according to claim 20 or 21 , wherein the cellulose product (1 ) comprises a lower end portion (40), an upper end portion (41 ) and a side wall (42) having an outer wall surface (43) and an inner wall surface (44), where the outer wall surface (43) and / or the inner wall surface (44) is provided with at least one protruding element (45).

23. A cellulose product according to claim 22, wherein the lower end portion (40) and / or the upper end portion (41 ) is provided with at least one protruding element (45).

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