A method for producing a cellulose product and a cellulose product

Abstract

A method for producing a three-dimensional cellulose product and a cellulose product (1) formed from a multi-layer cellulose blank structure (2), where the cellulose product (1) comprises a first paper layer (4), a dry-formed cellulose fibres layer (3) and a second paper layer (5), where the first paper layer (4) 5 and / or the second paper layer (5) is a stretchable paper layer.

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 three-dimensional shaped cellulose product from at least one stretchable paper layer and a layer of dry-formed cellulose fibres. The stretchable paper layer is preferably a type of crepe paper. The present disclosure also relates to a three-dimensional shaped cellulose product.

[0005] BACKGROUND

[0006] Cellulose fibres are often used as raw material for producing or manufacturing products. Products formed of cellulose fibres can be used in many different situations where there is a need for having sustainable products of flat or essentially non-flat shapes. A flat shape may refer to a generally two- dimensional shape and 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.

[0007] A low-price material commonly used for cellulose fibre products is wet moulded pulp. Wet moulded pulp has the advantage of being considered as a sustainable packaging material, since it is produced from biomaterials and can be recycled 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 The suction mould is then withdrawn from the suspension and the suction is generally continued to compact the deposited fibres while exhausting residual liquid.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. 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.

[0008] 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.

[0009] SUMMARY

[0010] An object of the present disclosure is to provide a method for producing a three-dimensional cellulose product 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. Another object of the present disclosure is to provide a three-dimensional shaped cellulose product.

[0011] The disclosure concerns a method for producing a three-dimensional cellulose product from at least one stretchable paper layer and a layer of dry-formed cellulose fibres, wherein the method comprises the steps of; forming a cellulose blank structure from a dry-formed cellulose fibres layer; arranging a first paper layer on a first side of the dry-formed cellulose fibres layer, where the first paper layer is stretchable; or arranging a first paper layer on a first side of the dry-formed cellulose fibres layer and arranging a second paper layer on a second side of the dry-formed cellulose fibres layer, where the first paper layer is stretchable; or arranging a first paper layer on a first side of the dry- formed cellulose fibres layer and arranging a second paper layer on a second side of the dry-formed cellulose fibres layer, where the first paper layer and the second paper layer are stretchable; and heating the multi-layer cellulose blank structure to a forming temperature in the range of 100°C to 300°C, forming the three-dimensional cellulose product from the multi-layer cellulose blank structure in a forming mould, by pressing the heated multi-layer cellulose blank structure with a forming pressure of at least 1 MPa, preferably 4-20 MPa, wherein the multi-layer cellulose blank structure is shaped into the three- dimensional cellulose product.

[0012] Advantages with these features are that the method provides an efficient manufacturing process for three-dimensional cellulose products with improved mechanical and chemical properties, where the cellulose products can be manufactured with high precision. The method also provides a cost-efficient and rational production of three-dimensional cellulose products through its few simple steps compared to traditional production methods. By the use of a stretchable paper layer on at least one side of the dry-formed cellulose fibres layer, a resulting cellulose product having a relatively deep shape can be provided, since the stretchable paper layer can stretch much more than an ordinary tissue layer. A regular tissue layer has a stretchability of up to 18- 20%, and by using a stretchable paper layer having a stretchability of more than 20% and up to 200%, a deeper cellulose product can be obtained.

[0013] A further advantage of using a stretchable paper layer is that a surface treatment of the cellulose product can be improved and simplified. In regular dry moulded fibre (DMF) products, a tissue paper is used as the outer layers on a cellulose product. A tissue layer is somewhat stretchable and relatively thin and due to this, it is also porous. The porosity is of advantage for the stretchability but a disadvantage of the porosity is that a surface treatment of a tissue layer will leave several “pinholes” in the surface treatment, such that the surface treatment will not protect the complete surface of the tissue layer. One way to mitigate this problem is to use a thicker surface treatment. Another way is to provide the cellulose product with a surface treatment after the forming of the cellulose product. Both a thicker surface treatment and an after treatment will increase the cost of the cellulose product, and an after treatment will also increase the production time.

[0014] By providing a stretchable paper layer with a surface treatment, the problem with “pinholes” can be avoided. Depending on the type of surface treatment, the surface treatment can be made before or after the paper is creped. A harder surface treatment is preferably applied after the paper is creped, and a softer surface treatment can be applied before the paper is creped, since the surface treatment will not be damaged by the creping process. By using a surface treated stretchable paper layer or an impregnated stretchable paper layer, a cellulose product that is resistant to e.g. grease, hot liquids, cold liquids and other substances that normally affects a cellulose product formed from only cellulose fibres can be obtained. The surface of the stretchable paper layer may be treated with a surface sizing or surface treatment resistant to e.g. liquid, grease or the like, such as AKD, latex, a thin plastic film or the like. The stretchable paper layer may also be sized or impregnated with a substance that can withstand e.g. liquid or grease, e.g. by mixing the treatment in the fibres of the stretchable paper or by dipping the stretchable paper in a treatment bath during production of the stretchable paper. The sizing substance may e.g. be resin, starch, AKD, ASA, HSMG or similar. An advantage of using a stretchable paper layer is that the stretchable paper layer is flexible, which simplifies the pressing of a cellulose product in the pressing mould, especially when the shape of the cellulose product is more complex, e.g. being a high and narrow cup also known as a deep drawn product, a bottle or a cellulose product having an undercut. A further advantage of using a stretchable paper layer is that the stretchable paper layer is closed, such that there is not a problem with “pinholes” in the treatment of the stretchable paper. Using a treated stretchable paper layer, the stretchable paper layer can function as a barrier for different substances. The stretchable paper layer is preferably a type of crepe paper. When one stretchable paper layer is used, the other paper layer can be a regular, relatively thin tissue layer. In the shown example, the dry-formed cellulose fibres layer is provided with a stretchable paper layer on at least one side of the dry-formed cellulose fibres layer. In one example, one side of the dry-formed cellulose fibres layer will be provided with a stretchable paper layer, and the other side will be provided with a tissue layer. One advantage of this is that a regular tissue layer is easier to handle in the production process. Another advantage is that a regular tissue layer may be cheaper than a stretchable paper layer. In another example, the dry-formed cellulose fibres layer is provided with a stretchable paper layer on each side of the dry-formed cellulose fibres layer. In this case, the properties of one stretchable paper layer may differ from the properties of the other stretchable paper layer. One layer may e.g. be a crepe paper having a first surface treatment, and the other layer may be a crepe paper having a second surface treatment. One layer may e.g. be treated to withstand grease and oil, and the other layer may be treated to withstand moist.

[0015] The stretchable paper layer may be relatively thin, depending on the requirements of the cellulose product. In one example, when the purpose of the stretchable paper layer is to act as a barrier for e.g. grease or a liquid, the layer should be as thin as possible but should still be possible to handle in the production line. A suitable paper weight may be in the region between 20-50 GSM (Grams per Square Meter). The stretchability of the stretchable paper layer is preferably adapted to the actual needs of the cellulose product. The stretchability of a crepe paper layer may be in the range of 20-200% or more. The used stretchable is preferably in the range of 20-40%, depending on e.g. the shape and depth of the cellulose product. Since one purpose of the stretchable paper layer is to provide a reliable barrier function for the cellulose product, the stretchability of the stretchable paper layer must not be much higher than for a regular tissue layer

[0016] The dry-formed cellulose fibres layer preferably has a fibre composition of 95- 100% cellulose fibres or natural cellulose fibres. The dry-formed cellulose fibres layer is formed in a dry-forming process where the cellulose fibres are carried and formed to the fibre layer structure by air as carrying medium. The multi-layer cellulose blank structure consists of the dry-formed cellulose fibres layer and at least one stretchable paper layer.

[0017] The cellulose product is formed in the forming mould during a forming time period in the range of 0.1 to 20 seconds, and preferably 1 to 10.0 seconds. The forming time together with the forming temperature and the forming pressure are important parameters in the forming of the cellulose product.

[0018] The cellulose product according to the invention is provided with a base layer made from air-laid dry-formed cellulose fibres that forms a dry-formed cellulose fibres layer. The cellulose product further comprises a first stretchable paper layer arranged on a first side of the dry-formed cellulose fibres layer; or a first stretchable paper layer arranged on a first side of the dry-formed cellulose fibres layer and a second paper layer arranged on a second side of the dry- formed cellulose fibres layer; or a first stretchable paper layer arranged on a first side of the dry-formed cellulose fibres layer and a second stretchable paper layer arranged on a second side of the dry-formed cellulose fibres layer. The stretchable paper layer may be arranged on the inner side or the outer side of the cellulose product, and may also be applied on both the inner side and the outer side of the cellulose product.

[0019] According to an aspect of the disclosure, the multi-layer cellulose blank structure is heated in the forming mould. This provides an efficient heating of the multi-layer cellulose blank structure.

[0020] According to another aspect of the disclosure, the cellulose product is shaped into a three-dimensional structure from the multi-layer cellulose blank structure during the forming in the forming mould. During the forming of the cellulose product in the forming mould, the cellulose product will achieve its three- dimensional shape.

[0021] BRIEF DESCRIPTION OF DRAWINGS The disclosure will be described in greater detail in the following, with reference to the attached drawings, in which

[0022] Fig. 1 shows schematically, a method for producing a cellulose product from a multi-layer cellulose blank structure according to the disclosure, and

[0023] Fig. 2a-b shows schematically, a cellulose product produced from a multilayer cellulose blank structure according to the disclosure.

[0024] DESCRIPTION OF EXAMPLE EMBODIMENTS

[0025] 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.

[0026] In the present detailed description, a method for producing a cellulose product from a multi-layer cellulose blank structure will be described.

[0027] Embodiments of sheet materials or blanks according to the disclosure are mainly discussed with reference to a multi-layer cellulose blank structure placed in position for forming in a forming mould, where the multi-layer cellulose blank structure has a flat shape. It should be noted that this will not limit the scope of the present disclosure, which for example may include, a multi-layer cellulose blank structure pre-shaped into a three-dimensional shape. The multi-layer cellulose blank structure may be presented to the forming mould in a shape similar to the desired final shape of the object if desired.

[0028] A cellulose product according to the disclosure may be made in a three- dimensional shape or formed into a three-dimensional shape from a two- dimensional blank or sheet material. Figure 1 schematically shows a method for producing a cellulose product 1 from a multi-layer cellulose blank structure 2, where the multi-layer cellulose blank structure 2 comprises a dry-formed cellulose fibres layer 3, a first paper layer 4 and a second paper layer 5.

[0029] With a dry-formed cellulose fibres layer is meant a cellulose fibre layer that is formed in a dry-forming process in which cellulose fibres are air-laid to form the cellulose fibre layer. When forming the cellulose fibre layer in the air-laid process, the cellulose fibres are carried and formed to the fibre layer structure by air as carrying medium. In the air-laid process, small amounts of water or other substances may if desired be added to the cellulose fibres in order to change the properties of the cellulose product, but air is still used as carrying medium in the forming process. The layer of dry-formed cellulose fibres may have a dryness that is mainly corresponding to the ambient humidity in the atmosphere surrounding the layer of dry-formed cellulose fibres.

[0030] To produce the cellulose products, the multi-layer cellulose blank structure may be arranged as a layered continuous web. The multi-layer continuous web may be formed from the layers in a continuous process step, where the continuous web is fed to the forming mould to form the cellulose products.

[0031] In the embodiment shown in Fig. 1 , the dry-formed cellulose fibres layer 3 is produced from loose and separated fibres produced in a mill 11 in a known manner, where defibrated fibres are fed by air as a carrying medium from the mill to a suitable substrate (not shown) to form the dry-formed cellulose fibres layer. The weight of the dry-formed cellulose fibres layer may be in the region between 200 -1000 GSM or more. The first paper layer 4 is provided on a first paper roll 8 and the second paper layer 5 is provided on a second paper roll 9.

[0032] As shown in figure 1 , a first pair of pressure feed rollers 13 may be used for compacting the dry-formed cellulose fibres layer 3 if required. A second set of pressure feed rollers 14 may be used to compact and unwind the first paper layer 4 and the second paper layer 5. In this embodiment, the first paper layer 4 is a tissue layer and the second paper layer 5 is a stretchable paper layer. The first paper layer 4 is arranged below the dry-formed cellulose fibres layer 3, and the second paper layer 5 is arranged above the dry-formed cellulose fibres layer 3, but the layers may suitably be arranged in the opposite order, depending on the used forming mould.

[0033] The second pair of pressure feed rollers 14 may be arranged so that the rollers are pushed against each other with a force Fi , and when the layers are passing between the pair of pressure feed rollers 14, the layers are compacted and forming the multi-layer cellulose blank structure 2. The force Fi may be chosen so that a desired compacting of the layers is achieved. Other suitable means may be used instead of the pair of pressure feed rollers 14, such as for example motorized unwinders for the web rolls.

[0034] As a non-limiting example, in order to achieve a desired compacting of the multi-layer cellulose blank structure, the force Fi of the pair of pressure feed rollers 10 may be in the range 2000 N to 17000 N, and the multi-layer cellulose blank structure may have a width of 0.6 m. The pair of pressure feed rollers 14 may be heated, for example to a temperature in the range of 70 °C to 170 °C, so that the multi-layer cellulose blank structure is heated during the compression in the pair of pressure feed rollers 14. The heating of the multilayer cellulose blank structure during compression will form a compressed ductile web structure that is suitable for being transported to and formed in the forming mould. The heating of the multi-layer cellulose blank structure may also be made in the forming mould by heating the forming mould.

[0035] Further according to the method, the multi-layer cellulose blank structure is arranged in the forming mould 7. The multi-layer cellulose blank structure may be arranged in the forming mould in any suitable way, and as an example, the multi-layer cellulose blank structure may be manually fed to and arranged in the forming mould. The multi-layer cellulose blank structure could as an alternative be intermittently fed to the forming mould by a suitable feeding unit if the multilayer cellulose blank structure is arranged as a continuous web transported with a constant speed, and the forming of the cellulose products in the forming mould may take place in intermittent process steps. The multi-layer cellulose blank structure may for example be intermittently fed to the forming mould via a feeding unit in the form of a buffer zone arrangement, where a pivot roller arm with a lift roller lifts and bends the multi-layer cellulose blank structure in a gentle arc with a synchronized servo controlled movement. In this way, a suitable length of the multi-layer cellulose blank structure is buffered to enable on-demand incremental feeding of the multi-layer cellulose blank structure into the forming mould. When the pivot roller arm is lowered, the buffered multilayer cellulose blank structure can be fed intermittently to the forming mould. The pivot roller arm is thus lifted and lowered in a repeated manner to accomplish the buffering of the multi-layer cellulose blank structure, so that the multi-layer cellulose blank structure is intermittently fed to the forming mould, via for example feeding rollers arranged after the pivot roller arm. The multilayer cellulose blank structure can also be fed to the forming mould as discrete, pre-cut pieces by a suitable feeding unit, such as an industrial robot or the like.

[0036] The multi-layer cellulose blank structure is according to the disclosure further heated to a forming temperature in the range of 100°C to 300°C. The cellulose product is formed from the multi-layer cellulose blank structure in the forming mould by pressing the heated multi-layer cellulose blank structure with a forming pressure of at least 1 MPa, preferably 4-20 MPa. By heating the multilayer cellulose blank structure and pressing the multi-layer cellulose blank structure in the forming mould, the cellulose product is formed, where during the forming the multi-layer cellulose blank structure is shaped into a three- dimensional fibre composite structure having a single-layer configuration.

[0037] In the embodiment shown in figure 1 , the multi-layer cellulose blank structure 2 is heated and formed into the cellulose product 1 , where the cellulose product 1 is having a three-dimensional bowl-shaped product configuration. However, as described above, the cellulose product 1 may have any desired three- dimensional shape. In the shown example, a first paper layer and a second paper layer are used, but it is possible to use only one paper layer, where the single paper layer is stretchable. The first paper layer 4 and the second paper layer 5 are unwound from the first paper roll 8 and the second paper roll 9 respectively, and the layers may be compressed by the second set of pressure feed rollers 14. In this way, the multi-layer cellulose blank structure 2 is formed.

[0038] In order to form the cellulose product, the multi-layer cellulose blank structure

[0039] 2 is positioned in the forming mould 7, where the multi-layer cellulose blank structure 2 is heated to a forming temperature in the range of 100°C to 300°C and then pressed in the forming mould 7 with a forming pressure of at least 1 MPa, preferably 4-20 MPa. The heating of the multi-layer cellulose blank structure 2 may take place before arranging the multi-layer cellulose blank structure 2 in the forming mould 7 or at least partly before the pressing in the forming mould 7. This may for example be accomplished through arranging a suitable heating unit in the manufacturing process. As an alternative, the heating of the multi-layer cellulose blank structure 2 may take place in the forming mould 7 when being pressed. The heating of the multi-layer cellulose blank structure 2 may for example be accomplished through heating the forming mould 7 before pressing the multi-layer cellulose blank structure 2.

[0040] When pressing the cellulose fibres, the cellulose fibres will be bonded to each other through hydrogen bonds in a way so that the resulting cellulose product will have good mechanical properties. Tests have shown that higher forming temperatures will give stronger bonding between the cellulose fibres when being pressed at a specific forming pressure. With forming temperatures above 100°C together with a forming pressure of at least 1 MPa, preferably 4- 20 MPa, the cellulose fibres will be strongly bonded to each other with hydrogen bonds. At temperatures higher than 300°C, the cellulose fibres will be thermally degraded and therefore temperatures above 300°C should be avoided. The forming pressure and the forming temperature may be chosen to be suitable for the specific cellulose product to be produced.

[0041] Tests have shown that when forming the cellulose product suitable pressure levels are, in the range of 1 -100 MPa, and suitable temperature levels are in the range of 100°C to 300°C. However, pressure levels in the range of 4-20 MPa, and temperature levels in the range of 140°C to 200°C are often sufficient in order to achieve cellulose products with desired properties.

[0042] An example of a cellulose product 1 is shown in Figs. 2a and 2b. In this embodiment, the cellulose product is a food tray. The cellulose product comprises a first paper layer 4, here a tissue layer, a dry-formed cellulose fibres layer 3, and a second paper layer 5, here a stretchable paper layer in the form of a crepe paper layer. In this example, the crepe paper layer is arranged on the inner side 6 of the food tray. The crepe paper layer 5 is preferably treated with a substance that resists e.g. liquid, grease or oil, depending on the intended use. If the food tray is to be used with a dry food product, a surface treatment of the crepe paper layer may not be necessary. The crepe paper layer may also be impregnated with a substance resistant to a liquid, grease or oil. By using a crepe paper layer as the inner layer, the risk that the inner layer burst or wrinkles during the pressing is minimizes, since the crepe paper layer may be more stretchable than a normal tissue layer. Further, the problem with “pinholes” is removed, since the surface treated crepe paper is less porous and will provide a good barrier. If a treated regular tissue layer would be used in a regular DMF product or in a relatively deep cellulose product, the protective layer may be either provided with “pinholes” or may be damaged during the pressing of the cellulose product, and consequently the protection of the cellulose product would be compromised. The shown food tray 1 comprises a bottom 15, side walls 16 and an upper rim section 17 that will increase the strength of the food tray and that can be used for a sealing film. The food tray has an inner side 6 and an outer side 10. The use of at least one stretchable paper layer may be advantageous when cellulose products having a relatively deep shape are produced, known as deep drawn products. A deep drawn product will have a high depth ratio compared to the width or diameter of the product, and / or will have relatively steep side walls. Such shapes may be difficult to produce using regular tissue layers, since regular tissue layers may not stretch enough. For less deep cellulose products, a regular tissue functions very good, and is more cost effective than an stretchable paper layer.

[0043] Further, in order to provide a reliable barrier protection of the cellulose product, i.e. such that the surface will resist grease, liquid, moist etc, the use of a surface treated crepe layer will ensure that the surface of the cellulose product is resistant to the desired substances. A surface treated crepe layer will ensure that the surface of the cellulose product is completely protected by the surface treatment of the crepe paper. A surface treated crepe layer will not exhibit any “pinholes” and will thus ensure that a cellulose product having the required properties can be produced in a cost-effective way.

[0044] 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 not be 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.

[0045] REFERENCE SIGNS

[0046] 1 : Cellulose product

[0047] 2: Multi-layer cellulose blank structure

[0048] 3: Dry-formed cellulose fibres layer

[0049] 4: First paper layer

[0050] 5: Second paper layer

[0051] 6: Inner side

[0052] 7: Forming mould

[0053] 8: First paper roll

[0054] 9: Second paper roll

[0055] 10: Outer side

[0056] 11 : Mill

[0057] 12: Pressing unit

[0058] 13: First set of application roller

[0059] 14: Second set of application roller

[0060] 15: Bottom

[0061] 16: Side wall

[0062] 17: Rim

Claims

CLAIMS1. A method for producing a three-dimensional cellulose product (1 ) from a multi-layer cellulose blank structure (2), wherein the method comprises the steps of; forming the multi-layer cellulose blank structure (2) from a dry- formed cellulose fibres layer (3); arranging a first paper layer (4) on a first side of the dry-formed cellulose fibres layer (3), where the first paper layer (4) is stretchable; or arranging a first paper layer (4) on a first side of the dry-formed cellulose fibres layer (3) and arranging a second paper layer (5) on a second side of the dry-formed cellulose fibres layer (3), where the first paper layer (4) is stretchable; or arranging a first paper layer (4) on a first side of the dry-formed cellulose fibres layer (3) and arranging a second paper layer (5) on a second side of the dry-formed cellulose fibres layer (3), where the first paper layer (4) and the second paper layer (5) are stretchable; and heating the multi-layer cellulose blank structure (2) to a forming temperature in the range of 100°C to 300°C, and forming the three-dimensional cellulose product (1 ) from the multilayer cellulose blank structure (2) in a forming mould (7), by pressing the heated multi-layer cellulose blank structure (2) with a forming pressure of at least 1 MPa, preferably 4-20 MPa, wherein the multi-layer cellulose blank structure (2) is shaped into the three-dimensional cellulose product (1 ).

2. A method according to claim 1 , wherein a surface of the stretchable paper layer comprises a surface treatment resistant to a liquid, grease or oil.

3. A method according to claim 1 ,wherein the stretchable paper layer is impregnated with a substance resistant to a liquid, grease or oil.

4. A method according to any of claims 1 to 3, wherein the stretchable paper layer is arranged on the inner side (6) of the cellulose product (1 ).

5. A method according to any of claims 1 to 3, wherein the stretchable paper layer is arranged on the outer side (10) of the cellulose product (1 ).

6. A method according to any of the preceding claims, wherein the stretchable paper layer has a paper weight between 20 - 50 GSM.

7. A method according to any of the preceding claims, wherein the stretchable paper layer has a stretchability of between 20-200%.

8. A method according to any of the preceding claims, wherein the dry-formed cellulose fibres layer (3) is formed in a dryforming process where the cellulose fibres are carried and formed to the dry-formed cellulose fibres layer (3) by air as carrying medium.

9. A method according to any of the preceding claims, wherein the stretchable paper layer is treated with a surface treatment or impregnated with a substance before the paper layer is creped.

10. A cellulose product (1 ) formed from a multi-layer cellulose blank structure (2), c h a r a c t e r i z e d i n that the cellulose product (1 ) comprises a first stretchable paper layer (4) and a dry-formed cellulose fibres layer (3);or a first stretchable paper layer (4), a dry-formed cellulose fibres layer (3) and a second paper layer (5); or a first stretchable paper layer (4), a dry- formed cellulose fibres layer (3) and a second stretchable paper layer (5).

11. A product according to claim 10, wherein the stretchable paper layer is arranged on the inner side (6) of the cellulose product (1 ).

12. A product according to claim 10, wherein the stretchable paper layer is arranged on the outer side (10) of the cellulose product (1 ).

13. A product according to any of claims 10 to 12, wherein the stretchable paper layer consists of 100% cellulose fibres.

14. A product according to any of claims 10 to 13, wherein one side of the stretchable paper layer comprises a surface treatment resistant to a liquid, grease or oil.

15. A product according to any of claims 10 to 14, wherein the stretchable paper layer is impregnated with a substance resistant to a liquid, grease or oil.

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