Solid cellulose foam product for protecting objects

Abstract

The present invention relates to a solid cellulose foam product for protecting an object, the solid cellulose foam product comprising at least one base portion comprising at least one hole and at least one accommodation chamber; the at least one accommodation chamber of the at least one base portion is arranged to accommodate a protruding portion of the object; and at least one plug disposed in the at least one aperture of the at least one base portion. The invention also relates to a method for producing said solid cellulose foam product.

Description

Technical Field

[0001] The present invention relates to the field of cellulose foam materials for packaging, more particularly to a solid cellulose foam product for protecting objects. The present invention further relates to a method for producing a solid cellulose foam product. Background Art

[0002] Plastic packaging materials such as fossil-based foams appear increasingly obsolete in a society striving to reduce plastic use and waste and move towards renewable materials. With regulators now pushing for policies that restrict or ban fossil-based foam materials in packaging, new solutions are needed.

[0003] There are many challenges in finding foam materials from renewable sources. Compared to established foams from oil (petroleum) based sources, many bio-based foams have higher production costs and lower mechanical properties, as well as poor stability in water or high temperatures. Bio-based and recyclable protective materials need to have the same excellent characteristics and properties as petroleum-based protective materials to become the first choice relative to petroleum-based materials.

[0004] The low weight and good shock absorption of bio-based foams are examples of key properties. Furthermore, the ability to tailor the shape and form of the bio-based foam to the shape and form of the item to be shielded by the protective material is of utmost importance.

[0005] The items to be shielded may often have protruding parts, such as corners and / or edges, which require additional protection from the packaging material during storage and transportation. In addition, the items may be made of highly fragile materials (such as glass or porcelain) that require protection due to their fragile nature. Bio-based foams on the market do not provide the necessary protection when the foam is subjected to constant corner or edge impacts during the delivery cycle.

[0006] Several bio-based foams containing cellulose have been described. WO20200011587 A1 describes a porous material prepared by aerating a paste containing cellulose fibers and gluten and depositing the aerated paste in a mold where it is dried. WO2015036659A1 describes a molded cellulosic product prepared by foaming an aqueous suspension of natural fibers combined with synthetic fibers and a surfactant, feeding the cellulosic foam to a mold where it is dried to produce a dry cellulosic product.

[0007] However, there is still a need for a solid cellulose foam that can be customized around sensitive products of any shape and protect every part of the product. Any protruding parts, such as corners or edges of the product, must be well shielded so that any shocks generated during storage and transportation will be absorbed by the surrounding cellulose foam and thus the shocks will not damage the protruding parts.

[0008] Furthermore, solid cellulose foams need to be renewable, biodegradable and fully recyclable in conventional paper and paperboard streams, allowing them to become part of the circular material stream in existing packaging waste management systems. The production costs of producing the foams and customizing their shape to any product shape must be modest in order to be a competitive option. Summary of the invention

[0009] The object of the present invention is to obviate at least some of the disadvantages of the prior art by providing a solid cellulose foam product for protecting objects according to claim 1 .

[0010] Due to the solution as defined in claim 1, protruding parts of the object will be very well protected from shocks and vibrations during storage and transport. Protruding parts of the object, such as corners, will be held in place by the housing in the base part of the solid cellulose foam product. The cushioning properties of the solid cellulose foam product will also protect the protruding parts. The presence of the plug will result in improved protective properties of the solid cellulose foam product.

[0011] Another advantage is that waste of cellulosic material is reduced or even eliminated, which reduces production costs and saves raw materials.

[0012] Compared to known methods, the method of the invention is easy to carry out in a large-scale setup.

[0013] Further aspects and embodiments are defined in the appended claims, which are specifically incorporated herein by reference. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The foregoing aspects and many of the attendant advantages of the present invention will become more readily understood as they become better appreciated by reference to the following detailed description when taken in conjunction with the accompanying drawings, in which:

[0015] Figure 1 is an exploded view of a preferred embodiment of a solid cellulose foam product;

[0016] Figure 2 It shows Figure 1 An oblique side view of a preferred embodiment of the invention having assembled components of the product;

[0017] Figure 3is an oblique view from above showing the assembled components Figure 1 A preferred embodiment of

[0018] Figure 4 An object is shown having its protruding portions protected by the solid cellulose foam product of the present invention according to the second preferred embodiment. DETAILED DESCRIPTION

[0019] Before disclosing and describing the present invention in detail, it should be understood that the present invention is not limited to the specific compounds, configurations, method steps, substrates and materials disclosed herein, because such compounds, configurations, method steps, substrates and materials may vary slightly. It should also be understood that the terminology employed herein is only for the purpose of describing specific embodiments and is not intended to be limiting, because the scope of the present invention is limited only by the appended claims and their equivalents.

[0020] The expression "flat object" as used herein means an object having a height, a width and a length. The width and the length define two surfaces, and the height defines at least one side wall. The height is so small relative to the length and the width that the object is referred to as a flat object. Examples of flat objects are tabletops, wall mirrors, door panels, glass panels, solar panels. The expression "flat" refers to an object having a horizontal surface without any protrusions or depressions from the surface.

[0021] The expression "protruding portion" as used herein means a portion protruding or bulging from a main portion, such that the protruding portion is more susceptible to damage and impact than the main portion. An example of a protruding portion is a corner of a flat object, such as a tabletop corner.

[0022] As used herein, the expression "a shape corresponding to the shape of the protruding portion" means a shape arranged to fit the shape of the protruding portion so that a protective material containing the corresponding shape can be arranged to surround and tightly enclose the protruding portion (or protruding portion) of an object to be protected by the protective material.

[0023] The expression "almost perpendicular to" as used herein includes a precision interval familiar and acceptable to a person skilled in the art, which interval is ±10%.

[0024] The expression "corner edge" as used herein refers to the edge extending between two corners. For a flat object, it is the edge extending between the two corners of a side wall.

[0025] As used herein, the term "foam" refers to a substance made by trapping air or gas bubbles inside a solid or liquid. Typically, the volume of the gas is much greater than the volume of the liquid or solid, with a thin film separating the gas pockets. In order to form a foam, three requirements must be met. Mechanical work is required to increase the surface area. This can occur by agitation, dispersing large amounts of gas into the liquid, or injecting the gas into the liquid. The second requirement is that a foam former must be present, typically an amphiphilic substance, a surfactant, or a surface-active component, to reduce the surface tension. Finally, the foam must form faster than it decomposes.

[0026] As used herein, the term "cellulose foam" refers to a foam comprising cellulose and other components such as thickeners, surfactants and additives. The main component of the cellulose foam is cellulose, such that cellulose constitutes at least 70 wt % of the dry content of the cellulose foam. The cellulose is in the form of fibers, so the foam may also be defined as a cellulosic foam or a cellulose fiber foam. The cellulose foam may be wet or solid.

[0027] As used herein, the term "wet foam" or "wet cellulose foam" refers to a wet foam comprising cellulose and other components such as thickeners, surfactants, and additives. Gas bubbles are present within the wet foam. The wet foam is free-standing and behaves as a viscoelastic solid. This means that the wet foam has both viscous and elastic properties. The wet foam will behave as a solid, and therefore free-standing, unless a force large enough is applied that it begins to flow and behaves instead as a viscous material. Depending on the magnitude and time scale of any applied shear stress, the wet foam may exhibit predominantly viscous or elastic behavior.

[0028] As used herein, the term "solid cellulose foam" or "dry cellulose foam" refers to a dry porous cellulose material, i.e., a foam-formed material, that has been formed from a wet cellulose foam. During the drying process, the closed wet cellulose foam is converted into an open solid cellulose foam. The network of cellulose fibers is prevented from collapsing during drying. Therefore, the solid cellulose foam will have a shape that corresponds to the shape of the wet cellulose foam to a large extent. The dry content of the solid cellulose foam may be at least 95 wt %, calculated based on the total weight of the solid cellulose foam. The shape and density of the solid cellulose foam are also maintained in an unrestricted state. The solid cellulose foam has an open cell structure, allowing air to occupy the pores within the foam. The solid cellulose foam may also be described as a porous material or a low density material.

[0029] The following detailed description and the examples contained therein are provided only for the purpose of describing and illustrating certain embodiments of the present invention and are not intended to limit the scope of the present invention in any way.

[0030] In a first aspect, the present invention relates to a solid cellulose foam product for protecting an object.

[0031] In a second aspect, the present invention provides a method of producing a solid cellulose foam product intended for protecting an object.

[0032] A first aspect of the present invention, namely a solid cellulose foam product for protecting an object, will now be described in detail hereinafter and with reference to the accompanying drawings.

[0033] exist Figure 1 In FIG. 1 , an exploded view of a preferred embodiment of a solid cellulose foam product 1 for protecting an object is shown, wherein the constituent components of the product 1 are shown. The components are shown in FIG. Figure 1 Orientation in the X-plane, Y-plane, and Z-plane.

[0034] The solid cellulose foam product 1 comprises two base parts 2 , 2 ′. Each base part 2 , 2 ′ comprises an inner surface 21 , an outer surface 22 , a rear surface 23 , a front surface 24 , an upper surface 25 and a lower surface 26 .

[0035] The inclined surface 27 connects the upper surface 25 and the front surface 24 .

[0036] Preferably, the inner surface 21 comprises a densified layer 210. More preferably, the outer surface 22 also comprises a densified layer 220. Most preferably, both the inner surface 21 and the outer surface 22 comprise a densified layer 210,220.

[0037] The two base parts 2, 2' are provided with a compression region 3, which comprises a compression surface 31, a wall surface 32 and a bottom surface 33. The compression region 3 further has a first compression depth DCR (depth of compression region) which corresponds to the width 32W of the wall surface 32 and also to the width of the bottom surface 33.

[0038] like Figure 1 It can be seen that the compressed area 3 is limited by the uncompressed area 28 and the inclined surface 27 of the base part 3 .

[0039] When the receiving chambers of the two or more base parts (e.g., the compression areas 3, 3') face each other, a receiving chamber 5 is formed (at Figure 2-3 ). It should be noted here that each base part contains its own receiving chamber (e.g., the compression areas 3, 3'), and these receiving chambers (e.g., the compression areas 3, 3') when facing each other will form a receiving chamber 5. Therefore, the term "receiving chamber" is used both for the receiving chamber on a separate base part and for the gap formed by arranging two or more base parts so that the receiving chambers of the separate base parts face each other.

[0040] Each base part 2, 2' further comprises three holes 4A, 4B.

[0041] exist Figure 1 In the figure, the holes are shown as through holes and will therefore be referred to as through holes hereinafter.

[0042] However, in some embodiments, at least one of the holes may be a blind hole having an opening in the inner surface 21 and extending from the inner surface 21 of the at least one base part 2, 2' and in a direction toward the outer surface 22 of the at least one base part, but not extending all the way to the outer surface 22, i.e., not reaching the outer surface 22.

[0043] The through holes 4A, 4B are arranged in a direction perpendicular or almost perpendicular to the inner surface 21 and the outer surface 22 of the base portion 2, 2'.

[0044] The through holes 4A, 4B are further arranged in an uncompressed region 28 of the base part 2, 2'.

[0045] exist Figure 1 , it is shown that the through holes 4A, 4B arranged in the uncompressed area 28 are in direct contact with the compressed area 3.

[0046] Two of the through holes, the side holes 4B, are arranged to be in direct contact with the compression area 3 through the respective surfaces 41b of the side holes 4B, so that the respective surfaces 41b respectively form a part of the wall surface 32 and the bottom surface 33 of the compression area 3. Thus, the openings 320, 330 are arranged in the respective wall surface 32 and the bottom surface 33.

[0047] A third through hole among the through holes is a corner hole 4A arranged at a corner edge 3 e of a corner of the compression region 3 .

[0048] The corner edge 3e of the compression area 3 is formed by the junction of the wall surface 32 and the bottom surface 33. In the embodiment shown, the corner has a right angle.

[0049] The through corner hole 4A is arranged to extend from the inner surface 21 of the corresponding base part 3, 3' to the outer surface 22 of the corresponding base part 3, 3', and extends in a direction parallel to the edge 36 between the wall surface 32 of the compression area 3 and the bottom surface 33 of the compression area 3.

[0050] Preferably, the corner hole 4A is arranged at the corner edge 3e, forming an angle A with the wall surface 32 and the bottom surface 33. The angle A is preferably in the interval of 30° to 60°, preferably 35° to 55°, and more preferably 40° to 50°. Figure 1 , the angle A is about 45°.

[0051] exist Figure 1 In the embodiment shown, three plugs 6 are further shown. In the shown embodiment, the plugs 6 have a rectangular shape corresponding to the rectangular shape of the through holes 4A, 4B.

[0052] The plug 6 comprises a respective contact surface 61 arranged to contact the compression zone 3 when inserted into the respective through hole 4A, 4B.

[0053] The contact surface 61 preferably comprises a densified surface 610 .

[0054] It will be appreciated that the shape of the through hole may be other than a rectangular shape. However, the plug may preferably have a shape corresponding to the shape of the through hole so as to fit into the hole.

[0055] Embodiments are also contemplated where one pair of holes and plugs may have one shape and another pair of plugs and holes may have a different shape than the first pair without departing from the scope of the present invention.

[0056] exist Figure 1 In the preferred embodiment shown, the base parts 2, 2' differ slightly from each other, ie they are not exact mirror images of each other, ie they are non-mirror image halves, and this difference will now be described.

[0057] One of the base parts 2 , 2 ′, namely the base part 2 ′, contains not only one but two compression regions 3 , 3 ′.

[0058] A second compression zone 3' is arranged on a portion of the compression surface 31 of the compression zone 3. The second compression zone 3' has a second compression depth DCR' which may have the same value as the first compression depth DCR of the first compression zone or be greater or less than the first compression depth DCR.

[0059] The total depth of the compressed surface 31 ′ from the uncompressed surface 28 to the second compressed region 3 ′ is the sum of the first compressed depth DCR and the second compressed depth DCR′, relative to the uncompressed surface 28 .

[0060] The second compression zone 3' further comprises a wall surface 32', a bottom surface 33' and a width 32'W of the wall surface 32' (and corresponds to the second compression depth DCR'). The width of the bottom surface 33' corresponds to the second compression depth DCR'. The second compression zone 3' and the compression surface 31' are limited by the inclined surface 27 of the base portion 2'.

[0061] The compression surface 3, 3' preferably comprises a densification layer 310, 310'.

[0062] By making partial cuts and pressing to different compression depths, the solid cellulose foam product can be tailored around protruding parts of the object to be protected and air entrainment is eliminated. The overall size and cost of the packaged product is thereby reduced. The compressed areas will also have increased stiffness compared to the uncompressed areas and will help to hold the object in place, for example, during transport.

[0063] The cushioning properties of the solid cellulose foam further ensure that the object remains protected.

[0064] Figure 2 and 3 The solid cellulose foam product 1 is shown in an assembled state.

[0065] The two base parts 2, 2' containing the compression areas 3, 3' are arranged fixedly to each other by means of fixing means. This is done by fitting the inner surfaces 21, 21' to each other in a non-detachable manner.

[0066] In some embodiments, the plug 6 is the fixing means, or at least helps to fix the base parts 2, 2' to each other.

[0067] The fixing means may further comprise, for example, glue, preferably a bio-based glue.

[0068] In some embodiments, the fixation device comprises the plug and glue.

[0069] By fitting the inner surfaces 21 of each base part 2 , 2 ′ to each other, a void V is formed and is defined by the compression areas 3 , 3 ′. The void is referred to as a receiving chamber 5 hereinafter.

[0070] In other words, the receiving chambers of the two or more base parts (the compressed areas 3 , 3 ′) face each other, thereby forming the receiving chamber 5 .

[0071] By forming the receiving chamber 5 from two or more base parts 2, 2', each containing a receiving chamber (the compressed area 3, 3'), the receiving chamber 5 (and therefore also the protruding parts of the object to be protected) will be placed in the center of the solid cellulose foam product 1, which provides good protection due to the optimal distribution of the forces. In contrast, if only one base part 2, 2' contains a receiving chamber, the protruding parts of the object to be protected will only be placed in this base part 2, 2', which in turn will reduce the protective properties of the product 1, because the forces will be unevenly distributed, for example during an impact.

[0072] The receiving chamber 5 includes bottom surfaces 33 , 33 ′, compression surfaces 31 , 31 ′, and wall surfaces 32 , 32 ′, wherein each of the surfaces included in the receiving chamber 5 together form a three-dimensional (3D) shape of the receiving chamber 5 .

[0073] The receiving chamber 5 is an open receiving chamber arranged to receive a protruding portion of the object to be protected and adapted to fit perfectly around the shape of the protruding portion and preferably in a tight manner leaving no empty space between the surface of the receiving chamber 5 and the protruding portion.

[0074] The plug 6 is arranged in the through hole 4 and only the bottom / top surface 62 of the plug is visible.

[0075] Preferably, said bottom and top surfaces 62 are aligned with said outer surface 22 of said base part 2, 2'.

[0076] In a second preferred embodiment, and as Figure 4 As shown, the two base parts 2, 2' are mirror images of each other, ie they are mirror image halves. Each of the two base parts contains only one compression region 3. When the two base parts 2, 2' are mirror images of each other, production is simplified.

[0077] Figure 4 An object O comprising four protruding parts is shown. Each of the four protruding parts is protected by a solid cellulose foam product 1 according to the invention.

[0078] The object O may preferably be a flat object O, such as a tabletop comprising four corners. In order to prevent the corners from breaking or cracking during storage and transportation, the solid cellulose foam product 1 of the present invention is fitted to the corners in the form of corner protectors. Due to the aspects defined in claim 1 and the dependent claims, the solid cellulose foam product 1 will absorb shocks in an excellent manner.

[0079] The protruding portion is arranged in the receiving chamber 5 of the solid cellulose foam product 1; the receiving chamber has a shape corresponding to the shape of the protruding portion of the object.

[0080] The receiving chamber around each protruding part comprises two base parts 2, each base part 2 comprising a corresponding compression area 3. The recesses of the compression areas 3 together form the receiving chamber 5.

[0081] It is conceivable that for more complex shapes of protruding portions, the solid cellulose foam product may include not only two but three or more base portions which are fixedly arranged to each other by fixing devices, and wherein the receiving chambers of the three or more base portions face each other, thereby forming the receiving chamber having a shape corresponding to the shape of the protruding portion of the object.

[0082] The holes 4A, 4B are arranged perpendicular to the protruding portion of the flat object O. Figure 4 In FIG. 5 , it is shown that the flat object O extends in the x- / y-plane and the holes extend in the z-direction. The holes extend in a direction perpendicular to the surface S of the flat object O.

[0083] At least one hole, a corner hole 4A, is arranged at a corner portion of the protruding portion, preferably at a corner edge portion of the protruding portion.

[0084] Since the accommodation chamber 5 has a shape corresponding to the shape of the protruding portion, the corner edge 3e of the compression region 3 of the accommodation chamber corresponds to the corner edge portion of the protruding portion.

[0085] The hole 4A is further arranged to have an angle (A) with the corner edge portion. The angle (A) is in the interval of 30° to 60°, preferably 35° to 55°, and more preferably 40° to 50°.

[0086] The two side holes 4B are arranged to pass through Figure 1 The openings 320 , 330 shown in FIG. 5 are in direct contact with the receiving chamber 5 (and thus with the protruding portion).

[0087] Since the holes 4A, 4B are arranged to be in direct contact with the accommodation chamber 5 , the plugs arranged in the holes come into contact with the protruding portions of the object to be protected inside the accommodation chamber at the positions of the openings 320 , 330 .

[0088] Preferably, the plug is arranged to contact the protruding portion via a respective surface comprising the densification layer.

[0089] Embodiments are conceivable in which the hole 4 is arranged at a smaller distance, for example 0.5-10 mm, from the wall surface 32 and the bottom surface 33 of the compression zone 3. Then, an area 28 of uncompressed material will be present between the hole 4 and the compression zone 3. In these embodiments, the plug will not be in direct contact with the receiving chamber and, therefore, also with the protruding portion.

[0090] The corner hole 4A is preferably arranged near the edge line 36 between the bottom surface 33 and the wall surface 32 of the compression area 3 and has the contact surface 61 arranged perpendicular to the edge line 36, as described above.

[0091] The corner hole 4A may be arranged close to the wall surface 32 and the bottom surface 33 , so that the edge line 36 may be removed by this arrangement.

[0092] However, embodiments are conceivable in which a small distance (eg 0.1-5 mm) may exist between the contact surface 61 and the edge line 36 .

[0093] Materials and material properties

[0094] The solid cellulose foam product comprises:

[0095] at least one base part 2 , 2 ′ comprising at least one hole and at least one receiving chamber;

[0096] - said at least one receiving chamber 5 of said at least one base part is arranged to receive a protruding part of said object; and

[0097] - at least one plug 6 arranged in the at least one hole 4 of the at least one base part 2, 2'.

[0098] The density of the uncompressed area 28 of the at least one base part 2, 2' is between 10 and 80 kg / m 3 , preferably 10-60kg / m 3 , and more preferably 20-50kg / m 3 within the range.

[0099] The average density of the at least one base part 2, 2' comprising the uncompressed area 28 and the compressed areas 3, 3' may preferably be in the range of 10-80 kg / m 3 , preferably 20-55kg / m 3 within the range.

[0100] The density of the at least one compressed area 3, 3' is 110% or more, preferably 120% or more and more preferably 130% or more of the density of the uncompressed area of ​​the at least one base portion.

[0101] The density of said at least one plug 6 is higher than said density of said at least one uncompressed zone of said at least one base portion.

[0102] The density of the at least one plug 6 is 110% or more, preferably 120% or more, and more preferably 130% or more of the density of the at least one uncompressed area of ​​the at least one base portion.

[0103] Preferably, said higher density of said plug 6 has been achieved by compressing said plug to said higher density.

[0104] The at least one plug 6 will provide improved protection against protruding portions of the object to be protected. During an impact, the cushioning properties of the cellulose based foam may not be sufficient to protect the protruding portions and the plug then provides additional protection against any protruding portions such as corners and / or edges. By providing a plug with a higher density, the stiffness and resilience of the plug is increased. This further improves the ability of the plug to protect the protruding portions during an impact.

[0105] The at least one base part 2, 2' comprises at least one surface comprising a densified layer.

[0106] The at least one compressed region 3, 3' of the at least one base portion 2, 2' further comprises the densification layer.

[0107] The at least one compressed region 3 , 3 ′ of the at least one receiving chamber 5 contains the densification layer.

[0108] The at least one plug 6 comprises at least one surface comprising a densification layer. A surface comprising a densification layer is harder than a surface without a densification layer. Therefore, advantageously, the at least one plug 6 comprises a densification layer on at least one surface. This provides additional rigidity to the plug 6, which is important for adequately protecting the protruding portion.

[0109] At least one surface of the at least one receiving chamber 5 is arranged in direct contact with the protruding portion.

[0110] The at least one surface of the at least one receiving chamber 5 arranged in direct contact with the protruding portion comprises the densified layer.

[0111] A surface comprising a densification layer is harder than a surface without a densification layer. It is therefore advantageous if the at least one surface of the at least one receiving chamber 5 arranged in direct contact with the protruding portion comprises a densification layer, as this will help to hold the protruding portion in position in the receiving chamber 5.

[0112] The at least one base part 2, 2' and the at least one plug 6 may preferably be prepared from a cellulose foam composition comprising:

[0113] a) 71 to 95 wt% of cellulose fibers, calculated based on the total weight of the solid content of the composition,

[0114] b) 4 to 24 wt% of a water-soluble thickener, based on the total weight of the solid content of the composition, and

[0115] c) at least two surfactants.

[0116] Cellulose fibers suitable for use in the present invention may be derived from wood, such as softwood or hardwood, from leaves or from fiber crops (including cotton, flax and hemp). Cellulose fibers suitable for use in the present invention may also be derived from regenerated cellulose such as rayon and lyocell. Cellulose fibers suitable for use in the present invention may include lignin or hemicellulose or both, or the cellulose fibers may be free of lignin and hemicellulose. Preferably, the cellulose fibers are derived from wood, and more preferably, the cellulose fibers are pulp fibers obtained by a pulping process that releases fibers from a wood matrix. Pulp fibers may be released by mechanical pulping to obtain mechanical pulp, such as thermomechanical pulp (TMP) or chemical thermomechanical pulp (CTMP), or released by chemical pulping, such as Kraft pulp or pulp obtained by sulfite process, soda process or organic solvent pulping process. More preferably, the cellulose fibers are pulp fibers released by chemical pulping processes. The different characteristics of each cellulose fiber will affect the properties of the final cellulose foam. The length of the cellulose fibers is significantly greater than their width. The cellulose fibers may have an average width of 0.01 to 0.05 mm. The fiber length of softwood can be 2.5 to 4.5 mm, while hardwood can have a fiber length of 0.7 to 1.6 mm, and eucalyptus can have a fiber length of 0.7 to 1.5 mm. However, the fiber length can vary significantly with different growing locations, etc. The cellulose fibers in the cellulose foam disclosed herein can have a length of 0.1 mm to 65 mm, or 0.1 mm to 10 mm, or 0.5 mm to 65 mm, or 0.5 mm to 10 mm, or 0.5 mm to 7 mm. The fiber length can provide different mechanical properties for the foam. Due to the length of the fiber, they can be entangled with each other and give the mutual combination of fiber and fiber, which brings strength to the foam. The aspect ratio (i.e., the ratio of fiber length to fiber width) of the cellulose fiber in the cellulose foam according to the present invention can be at least 10, at least 25, at least 50, at least 75 or at least 100, which provides the preservation and stability of the foam structure during the drying procedure, so that the wet cellulose foam with a shape retention can be dried. The aspect ratio may be up to 6500, or preferably up to 2000.

[0117] The cellulose fibers may be modified to provide different properties to the final cellulose foam. For example, phosphorylated fibers or periodate-oxidized fibers may also be used when producing cellulose foams according to the present invention.

[0118] The cellulose fibers of the cellulose-based foam composition may be selected from wood pulp; regenerated cellulose fibers; and plant fibers, such as fibers from bamboo, cotton, hemp, flax and jute.

[0119] Preferably, the cellulosic fibers are selected from wood pulp, such as softwood pulp, hardwood pulp, chemi-thermomechanical pulp, and from dissolving pulp, or a combination of one or more of these.

[0120] More preferably, the cellulosic pulp fibers are selected from softwood pulp, chemi-thermomechanical pulp or dissolving pulp.

[0121] Most preferably, the cellulosic pulp fibers are selected from softwood pulp, such as softwood bleached kraft pulp.

[0122] The water-soluble thickener may be present in an amount of 4-24 wt % or 5-20 wt %, calculated based on the total weight of the solid content of the foam. The thickener may have a molecular weight of 80 000-250 000 g / mol, or 83 000-197 000 g / mol. Exemplary water-soluble thickeners are selected from carboxymethyl cellulose (CMC), methyl cellulose (MC), hydroxyethyl cellulose (HEC), ethyl hydroxyethyl cellulose (EHEC), methyl hydroxypropyl cellulose (MHPC), starch, xanthan gum, guar gum and xyloglucan or mixtures thereof.

[0123] The foam preferably comprises a mixture of at least two surfactants. One of the at least two surfactants is preferably a fast-acting surfactant that settles rapidly at the air-water interface during mechanical agitation during the preparation of the foam, which helps to form a foam with high density and high viscosity, and thus achieves a self-standing foam. Suitable surfactants for this purpose are anionic surfactants, preferably low molecular weight anionic surfactants. The low molecular weight anionic surfactant can be selected from sodium dodecyl sulfate (SDS); potassium dodecyl sulfate, sodium laureth sulfate (SLES); sodium dodecylbenzene sulfonate; sodium cocoyl sarcosinate; sodium lauroyl sarcosinate. The low molecular weight anionic surfactant is preferably selected from sodium dodecyl sulfate (SDS); sodium p-dodecylbenzene sulfonate; sodium cocoyl sarcosinate; and sodium lauroyl sarcosinate. More preferably, the low molecular weight anionic surfactant is sodium cocoyl sarcosinate. The anionic surfactant may be biodegradable.

[0124] The other of the at least two surfactants is preferably a cosurfactant. The cosurfactant may be selected from high pKa fatty acids, for example, selected from plant-derived raw materials, such as myristic acid, sodium oleate, lauric acid, palmitic acid and stearic acid; glucose-based cosurfactants with aliphatic carbon tails, such as alkyl glycosides, alkyl polyglucosides, alkyl thio-glycosides and alkyl maltosides; amphoteric betaines, such as cocamidopropyl betaine (CAPB) and sodium cocoimidodipropionate (CADP); polyethylene glycol sorbitan monolaurate, i.e. (For example 20. 80 and 85); and polyoxyethylene lauryl ethers, such as polyethylene glycol lauryl ether, pentaethylene glycol monododecyl ether and octaethylene glycol monododecyl ether.

[0125] The foam composition can preferably be prepared by a process comprising the following steps:

[0126] a) disintegrating cellulose fibers in water to obtain a pulp of cellulose fibers;

[0127] b) adding a thickener to the pulp obtained in a) to obtain a mixture of thickener and cellulose fibers in water;

[0128] c) adding the at least two surfactants to the mixture obtained in b) to obtain a fiber suspension;

[0129] d) aerating the suspension obtained in c) to obtain a wet foam,

[0130] The wet foam comprises 10-38 wt% of cellulose fibers, 0.5-10 wt% of the water-soluble thickener and 0.1-2 wt% of a surfactant, based on the total weight of the wet foam.

[0131] And wherein the wet foam has 140-500kg / m 3 density and yield stress of 40 to 400 Pa;

[0132] e) Drying the wet foam obtained in d) to obtain a dry cellulose foam.

[0133] The wet foam can be dried without the use of a mold, ie, the wet foam is free-standing and retains its shape during drying without the need for a mold.

[0134] The wet foam is uniform and has good stability due to the small bubble size (typically below 100 μm) obtained when the mixture of cellulose fibers, thickeners and surfactants is aerated. The wet foam does not flocculate during processing. During any subsequent processing or drying steps, the average bubble size is largely maintained, and the cellulose fibers remain well dispersed. The resulting solid cellulose foam obtained by drying the wet foam will be uniform, firm, have good mechanical properties, smooth surface and no defects in structure. In contrast, the wet cellulose foam with low stability has a larger average bubble size (i.e., typically above 100 μm) and the bubbles will coalesce faster during processing and drying to form larger bubbles. In addition, the cellulose fibers will form clusters during processing and drying. This causes the wet foam to collapse during drying. The resulting solid cellulose foam will not have a uniform structure and will also contain defects in the form of cavities produced by the coalesced bubbles in the wet foam. Due to the defects, such solid cellulose foam is weak and has a rough surface.

[0135] The dried cellulose foam obtained in step e) can be used as a solid cellulose foam material.

[0136] The dried cellulose foam obtained in step e) can be obtained by a process comprising the following steps:

[0137] Depositing discrete units of cellulose foam on a surface to obtain a first foam deposit, depositing wet cellulose foam between the discrete units to obtain subsequent foam deposits, and drying the wet foam to obtain a solid foam wherein the discrete units of foam are embedded in a foam matrix. The solid cellulose foam can then be used as the solid cellulose foam of claim 1 and its dependent claims.

[0138] However, without departing from the scope of the present invention, the solid cellulose foam may be prepared by other methods than those described above. For example, the solid cellulose foam may be prepared by a single deposition of wet foam into any desired shape. Optionally, any suitable confinement device may be used, such as a mold or a frame.

[0139] The solid cellulosic foam material can be prepared, for example, by depositing the foam composition on the forming section of a conventional papermaking machine for forming foam webs or a papermaking machine suitably modified for the purpose.

[0140] The cellulose foam compositions of the at least one base part 2, 2' and the at least one plug 6 may be the same or different.

[0141] The solid cellulose foam is preferably not a memory foam that returns to its original shape, but rather the foam retains its compressed shape. The solid cellulose foam has an open cell structure of the bulk of the foam. When compressed, the cellulose foam will deform and cannot return to its original shape.

[0142] Examples of conceivable dimensions are solid cellulose foam boards with a thickness in the range of from 1 cm to 20 cm, or from 1 cm to 10 cm, or from 1 cm to 5 cm, or from 4 cm to 6 cm. In one embodiment, the thickness is 50 mm. The at least one base portion may be cut from such a board, and the thickness of the board may preferably correspond to the width of the rear surface 23 of the at least one base portion.

[0143] For embodiments where the higher density of the plug is achieved by compression, the plug may for example be compressed to 40% of the thickness of the board, ie the thickness of the compressed plug is 20 mm.

[0144] The dimensions described are used as examples only and should not be considered to limit the products of the present invention to the described dimensions.

[0145] As mentioned before, an embodiment may be preferred in which at least one surface of the at least one base portion 2, 2', the at least one compressed area 3, 3', the uncompressed area 28 and the at least one plug 6 comprises a densified layer.

[0146] The production of solid cellulose foam comprises different production steps, one of which is a drying step. During the drying step, the outer surfaces of the foam (top surface, bottom surface, side surfaces) will acquire an outer layer having different properties from the main part of the foam comprising a more uniform open-cell porous fiber network. The outer layer has a higher density than the density of the main part, because the fibers are more densely packed and partly differently oriented. The outer layer is called a "densification layer". The densification layer will provide improved mechanical stability and improved strength to the foam.

[0147] Since the densified layer has improved mechanical stability and provides strength to the foam, it is preferred to orient the surface containing the densified layer towards the direction where additional shock absorption may be required. The improved properties of the densified layer are used in locations of the product where they may contribute to the protective properties of the product.

[0148] Despite the higher density, the densified layer is still highly porous and air permeable.The densified layer has a negligible effect on the overall density of the solid cellulose foam.

[0149] A second aspect of the invention, namely a method for producing a solid cellulose foam product intended for protecting objects, will now be described in detail hereinafter and with reference to the accompanying drawings.

[0150] The method for producing a solid cellulose foam product comprises the following steps:

[0151] a) providing at least one base part;

[0152] b) forming a receiving chamber in the at least one base portion, the receiving chamber being arranged to receive a protruding portion of an object;

[0153] c) providing said at least one base portion with at least one hole;

[0154] d) Providing at least one plug, which is arranged to be introduced into the at least one hole.

[0155] Preferably, the method further comprises:

[0156] step b1) performs at least one cutting line of a predetermined cutting depth into at least one surface of said at least one base part, whereby said at least one cutting line defines at least one pattern on said at least one surface, and preferably,

[0157] Step b2) presses at least one pressing tool into the at least one pattern of the at least one surface of the at least one base part, thereby forming at least one compressed area of ​​the base part; the at least one compressed area forms a receiving chamber, which is arranged to receive a protruding part of the object.

[0158] Step a) comprises providing at least one base part 2, 2'.

[0159] The base part 2, 2' may preferably have a rectangular or square shape to easily fit into a surrounding rectangular packaging.

[0160] The base portion 2 , 2 ′ further has a thickness X corresponding to the width of the rear surface 23 and the front surface 24 .

[0161] exist Figure 1 In the embodiment, the base part 2 , 2 ′ comprises an inclined surface 27 .

[0162] Step b) forms a receiving chamber 5 in the at least one base part 2 , 2 ′, said receiving chamber 5 being arranged to receive a protruding part of the object O.

[0163] Step b) further comprises step b1):

[0164] At least one cutting line having a predetermined cutting depth is provided into at least one surface 21 of the at least one base part 2 , 2 ′, whereby the at least one cutting line defines at least one pattern on the at least one surface 21 .

[0165] At the portion where the at least one cutting line is to be provided, the at least one base portion 2, 2' has a thickness X; the thickness X is in the interval 2-20 cm, preferably 3-10 cm, and most preferably 4-6 cm.

[0166] A cutting tool (not shown), such as a knife or a cutting blade or some other kind of relevant and sharp-edged cutting tool, is preferably arranged at a starting position close to the at least one surface 21 intended to be cut into.

[0167] After positioning the cutting tool in a suitable starting position, the cutting tool is moved in a direction towards the at least one surface 21. This movement brings the cutting tool into direct contact with the at least one surface 21, and the movement of the cutting tool continues so that the cutting tool starts cutting into and through the surface 21 and into the core of the at least one base part 2, 2'.

[0168] The at least one cutting line is arranged to partially cut through the thickness X of the at least one base part 2, 2' to a predetermined cutting depth such that the predetermined cutting depth is smaller than the thickness X of the at least one base part 2, 2'.

[0169] The movement of the cutting tool into the at least one foundation part 2, 2' (and the cutting operation) continues until the predetermined cutting depth is reached. The cutting tool is then removed from the at least one foundation part 2, 2', leaving a cutting line in the at least one foundation part 2, 2'.

[0170] The predetermined cutting depth of the at least one cutting line is preferably 90% or less, more preferably 70% or less, and most preferably 60% or less of the thickness X of the cellulose foam material 1 .

[0171] In some embodiments, the cutting tool comprises two or more knives or blades. When using a cutting tool with two or more knives or blades, two or more patterns can be cut at once in the same cutting operation, i.e. in one step. It is also conceivable that two or more knives or blades perform cutting lines of different cutting depths.

[0172] It is also conceivable to use a cutting tool with only one knife or blade, and to use two or more cutting tools with variable shapes and cutting depths, and to repeat step b1) for each cutting tool.

[0173] Repeating step b1) to provide said at least one cutting line may be performed before step b2) of pressing, or alternately with step b2).

[0174] In some embodiments, the cutting tool may, in its simplest form, have a linear shape that provides a linear cut.

[0175] In other embodiments, the cutting tool may have a more complex shape and provide a curved cut and / or a cut formed as a closed loop.

[0176] The at least one cutting line arranged on the at least one surface 21 of the at least one base part 2, 2' defines at least one pattern on the at least one surface 21 of the at least one base part 2, 2'.

[0177] exist Figure 1 In the embodiment shown in , the surface of the at least one pattern is defined by at least one cutting line and at least one edge of the at least one base part 2 , 2 ′.

[0178] In other embodiments, the surface of the at least one pattern may be defined by at least one linear cut line and at least one curved cut line.

[0179] Step b1) of the process is followed by a pressing step, step b2).

[0180] Step b2) comprises pressing at least one pressing tool into at least one pattern of at least one surface of at least one base part, thereby forming at least one compressed area 3, 3' of the base part; the at least one compressed area 3, 3' forms a receiving chamber 5 arranged to accommodate a protruding part of the object O.

[0181] The pressing step b2) preferably starts with positioning the at least one pressing tool to a starting position near the at least one pattern, and then moving the at least one pressing tool toward the pattern of the at least one surface 21 so that the at least one pressing tool contacts the surface of the pattern and applies pressure on the surface of the pattern, thereby compressing the material of a portion of the at least one base part 2, 2'.

[0182] Said pressure applied by said at least one pressing area of ​​said at least one pressing tool causes said at least one pattern to be compressed in a direction coinciding with the direction of said pressing and further compressed into the core of said at least one base part 2, 2'.

[0183] After a predetermined compression depth has been reached by the pressing, the pressing tool is removed.

[0184] exist Figure 1 In it is shown that the at least one compression has been performed in a direction from the inner surface 21 and perpendicularly towards the outer surface 22; and the direction is parallel or almost parallel to the front surface 24 and the rear surface 23 of the at least one base part 2, 2'.

[0185] After the at least one pressing step has been completed, at least one compressed area 3, 3' is formed in the at least one base part 2, 2'.

[0186] The at least one pressing tool may preferably have at least one pressing area which corresponds to or is smaller than the area / the surface of the at least one pattern of the at least one surface 21 .

[0187] In some embodiments, the at least one pressed area may comprise an edge line surrounding the at least one pressed area, and the pressed edge line may preferably be arranged to coincide with the at least one cutting line during the pressing step.

[0188] The edge line may preferably be a right-angled edge line.

[0189] For articles of more complex shape, the at least one pressing tool may have more than one pressing area. The pressing areas may have different sizes.

[0190] In some embodiments, each pressed area may have a corresponding pressed edge line that is a right angle.

[0191] However, embodiments can be envisaged in which at least one of the pressed areas may have a curved edge line.

[0192] The pressing areas of different sizes may also have different shapes and be arranged to penetrate and compress the at least one surface 21 to different pressing depths. The thickness of the pressing tool corresponds to the different pressing depths.

[0193] In some embodiments, the pressing direction may not be parallel to the front surface 24 and the rear surface 23 of the at least one base part 2, 2' but may be performed at an angle to the front surface 24 and the rear surface 23. In these embodiments, it may be preferred that the at least one cutting line also has the same angle as the pressing direction.

[0194] In some embodiments of the present invention, step b1) and step b2) are performed simultaneously. The cutting tool and the pressing tool are the same tool, ie a combined tool that performs both cutting and pressing operations.

[0195] Said combined tool preferably comprises at least one sharp edge for providing said cutting and at least one pressing area for carrying out the compression of said at least one base part 2, 2'.

[0196] In the embodiment where the combination tool is used and step b1) and step b2) are performed simultaneously as a combination step, it is conceivable to perform the combination step not only once but also to repeat the combination step two or more times.

[0197] Regardless of whether cutting and pressing are performed as separate steps or as a combined step, the at least one base portion 2 , 2 ′ now comprises at least one compressed region 3 , 3 ′ and at least one uncompressed region 28 .

[0198] The at least one compressed region 3, 3' comprises a compressed solid cellulose foam having a compressed thickness CMT, CMT', the compressed region 3, 3' further having a volume.

[0199] In some embodiments, the pressing step is performed until the pressing depth is equal to the predetermined cutting depth.

[0200] In other embodiments, the pressing depth PD may be less than or greater than the predetermined cutting depth DC.

[0201] The compressed thickness CMT, CMT′ may be calculated as the thickness X of the uncompressed area 28 of the at least one base portion 2, 2′ at the location for the at least one cutting line minus the depth DCR, DCR′ of the compressed area:

[0202] CTM=X-DCR

[0203] CTM′=X–(DCR+DCR′)

[0204] The at least one base part 2, 2' provided in step a) preferably has a uniform bulk density and preferably also has at least one densified layer. Pressing the at least one pressing tool into the at least one pattern of the at least one base part 2, 2' results in a density of the solid cellulose foam contained in the at least one compressed area 12 being higher than the density of the provided - and uncompressed - solid at least one base part 2, 2'.

[0205] The density of the at least one compressed area 3, 3' is 110% or more, preferably 120% or more and more preferably 130% or more of the density of the uncompressed area of ​​the at least one base portion.

[0206] An embodiment is conceivable in which the pressing tool is the object O to be protected, ie when inserted into said protruding portion of said object, pressure is exerted by the object so that the object itself compresses the foam and creates the receiving chamber 5 .

[0207] In other embodiments, the pressing tool only partially causes compression, and the remaining compression is performed by inserting the object O.

[0208] like Figure 1-3 As shown, one of the base parts 3, 3', namely the base part 3', has two compressed areas 3, 3'. Two or more compressed areas can be produced by repeating step b1) providing the at least one cutting line, which can be performed before step b2) of the pressing step or alternately with the pressing step b2).

[0209] Step c) comprises providing said at least one base part with at least one hole.

[0210] The at least one hole 4 may be a through hole or a blind hole. Embodiments comprising two or more holes 4 may comprise a mixture of through holes and blind holes.

[0211] In the figures, the at least one hole 4 is a through hole with a rectangular cross-sectional area, but other shapes are conceivable, such as square, triangle, cylinder, star or other conceivable shapes, without departing from the scope of the present invention.

[0212] In some embodiments, the corner hole 4A may have an L-shape, which is arranged around the corner edge 3e of the compression area 3 and thus around the corner of the protruding portion.

[0213] Preferably, said at least one hole 4 is arranged from said inner surface 21 of the uncompressed region 28 and towards said outer surface 22 of said at least one base part 2, 2'. In the embodiment shown in the figures, said hole 4 extends to said surface 22 and forms an opening therein.

[0214] In the embodiment in which the at least one hole 4 is a blind hole, the blind hole has an end inside the at least one base part 2 , 2 ′ and does not reach the outer surface 22 .

[0215] The at least one hole 4 may be provided by a cutting tool.

[0216] The at least one hole is arranged at the location of the at least one base part 2, 2' as already disclosed in relation to the first aspect of the invention.

[0217] Step c) comprises providing at least one plug arranged to be introduced into said at least one hole.

[0218] The at least one plug 6 can be manufactured as a rod that is cut into plug pieces of appropriate length. Each covered surface of the at least one plug 6 will have a dense layer. However, the surface of the cutout will not have the dense layer.

[0219] The plug 6 can be manufactured separately. All sides of the plug 6 will have a dense layer.

[0220] The density of the at least one plug 6 is higher than the density of the uncompressed region 28 of the at least one base part 2, 2'. The thickness of the densification layer is so small, ie the densification layer is so thin, that the higher density of the densification layer has no influence on the density of the at least one plug 6.

[0221] The density / average density of the at least one plug 6 is higher than the average density of the at least one base portion 2, 2' comprising the compressed area 3, 3' and preferably also comprises at least one densified layer.

[0222] It is noted that the densification layer is so thin that its density has only a very small effect on the average density of the corresponding plug and base part compared to the average density of the corresponding plug and base part in the embodiment without any densification layer. The densification layer is similar to a thin skin on the surface.

[0223] The density of the at least one plug 6 is 110% or more, preferably 120% or more, and more preferably 130% or more of the density of the uncompressed area 28 of the at least one base portion.

[0224] Said higher density of said at least one plug may be obtained by compressing said at least one plug 6 .

[0225] Said compression of said at least one plug 6 is at least 10%, more preferably 20% and most preferably 30% of the thickness before said compression and as measured in the compression direction.

[0226] Preferably, the at least one plug 6 has a shape complementary to the shape of the at least one hole 4 into which the plug 6 is to be inserted.

[0227] In embodiments where the corner hole 4A is L-shaped, the plug 6 intended to be arranged in the corner hole 4A will have a corresponding L-shape.

[0228] In the embodiment in which the at least one plug 6 has only one covering surface comprising the densification layer, the covering surface comprising the densification layer is the contact surface 61 arranged to contact the protruding portion of the object O to be protected.

[0229] In an embodiment in which the solid cellulose product comprises two or more base parts 2, 2', the method further comprises the step of arranging the two or more base parts 2, 2' to be firmly fixed to each other by a fixing device; the corresponding receiving chambers 5 of the two or more base parts 2, 2' face each other, thereby forming the receiving chamber 5 arranged to accommodate the protruding part of the object O.

[0230] It should be understood that the voids V of the at least one compressed area 3, 3' of each base part form the receiving chamber of each base part. The volume of the formed receiving chamber 5 is the sum of the volumes of the voids V.

[0231] In some embodiments of the invention, the solid cellulose foam product comprises only one base part 2. The receiving chamber 5 may be provided in the one base part by cutting out a volume of cellulose foam of the one base part.

[0232] In yet other embodiments of the present invention, the solid cellulose foam product comprises three or more base parts fixedly arranged to each other, and wherein the compression areas / receiving chambers of two or more of the base parts face each other, thereby forming a shape corresponding to the shape of the protruding part of the object.

[0233] As will be appreciated by those skilled in the art, numerous changes and modifications may be made to the above-described and other embodiments of the invention without departing from the scope of the invention as defined in the appended claims.

[0234] For example, embodiments can be envisaged which do not have an inclined surface connecting the upper surface and the front surface. Instead, the upper surface meets the front surface, preferably in perpendicular contact.

[0235] It should be noted that the above aspects may be the subject of their own protection, for example in a separate divisional application. Thus, it is foreseeable that this aspect of the invention may require its own protection, for example because it may also be applicable to other concepts than those defined by the independent claims in this application.

[0236] Example

[0237] Example 1

[0238] The solid cellulose foam product for protecting the corners and edges of flat objects is prepared from a solid cellulose foam board having a thickness of 5 cm. The cellulose foam is dry and has a density of 32 to 35 kg / m 3and contains 83 to 88 wt% cellulose fiber (softwood bleached kraft pulp), 10 to 15 wt% thickener (CMC) and about 2 wt% surfactant (a mixture of myristic acid and sodium cocoyl sarcosinate). The foam board has a densification layer on the top and bottom sides. The corner protection product is prepared by cutting the foam board into corresponding Figure 1 The foam board is formed by two base parts of those shown in . Cutting is performed using a cutting table. After cutting, the densification layer is also present on the top and bottom surfaces, i.e. the base part has the same thickness as the foam board. Three through holes are formed in each base part by cutting. The accommodation chamber is formed by pre-cutting a pattern corresponding to the accommodation chamber and then pressing. Three plugs are formed by cutting and compressing the foam board into a plug with a densification layer on both surfaces. The thickness of the plug before compression is 5 cm, and it is 2 cm after compression.

[0239] The corner protection product is assembled by attaching the two base parts to each other with glue. The plug is inserted into the hole, and the plug is arranged so that the densified layer faces the receiving chamber. The assembled corner protection product is similar to Figure 2 and Figure 3 Products shown in .

[0240] To test the protective properties of the corner protection product, the corner of a flat tabletop is inserted into the receiving chamber of the corner protection product. A drop test is performed in which the tabletop is dropped on the corner protected by the corner protection product. After the drop, the tabletop is inspected for any damage.

[0241] Discover corner protection products that can protect the corners of your desk.

[0242] Example 2 - Comparative

[0243] In a comparative example, a cellulose foam sheet was cut into two base portions as described in Example 1, but without forming any holes and without any plugs.

[0244] The corner protection product was assembled by attaching the two base parts to each other with glue. The protection properties were tested as described in Example 1. It was found that the corner protection product broke into two halves upon impact and therefore could not protect the table top.

Claims

1. A solid cellulose foam product (1) for protecting an object (O), the solid cellulose foam product (1) comprising: - at least one base part (2, 2') (2, 2') comprising at least one hole (4) and at least one receiving chamber (5); - said at least one receiving chamber (5) of said at least one base part (2, 2') (2, 2') is arranged to receive a protruding part of said object (O); and - at least one plug (6) arranged in the at least one hole (4) of the at least one base part (2, 2').

2. A solid cellulose foam product according to claim 1, wherein the at least one receiving chamber (5) has a shape corresponding to the shape of the protruding portion of the object.

3. A solid cellulose foam product according to claim 1 or 2, wherein when the object is arranged in the at least one receiving chamber (5), the at least one hole (4) is arranged perpendicular to the protruding portion of the object (O).

4. A solid cellulose foam product according to any one of the preceding claims, wherein the at least one hole (4) is arranged at a corner portion of the protruding portion.

5. A solid cellulose foam product according to claim 4, wherein the at least one hole (4) is arranged at a corner edge portion of the corner portion and further arranged to have an angle (A) with the corner edge portion.

6. A solid cellulose foam product according to claim 5, wherein the angle (A) is in the interval of 30° to 60°, preferably 35° to 55°, and more preferably 40° to 50°.

7. A solid cellulose foam product according to any one of the preceding claims, wherein the at least one hole (4) is arranged in direct contact with the receiving chamber (5).

8. A solid cellulose foam product according to any one of the preceding claims, wherein the at least one hole (4) is a through hole or a blind hole.

9. A solid cellulose foam product according to claim 8, wherein the blind holes extend from the inner surface of the at least one base portion (2, 2') and in a direction towards the outer surface of the at least one base portion (2, 2') (2, 2').

10. A solid cellulose foam product according to any one of the preceding claims, wherein the solid cellulose foam product comprises two or more base parts which are fixedly arranged to each other by a fixing device, and wherein the receiving chambers (5) of the two or more base parts face each other, thereby forming the receiving chamber (5) having a shape corresponding to the shape of the protruding part of the object.

11. A solid cellulose foam product according to claim 10, wherein the fixing means comprises the at least one plug (6).

12. A solid cellulose foam product according to any one of the preceding claims, wherein the at least one plug (6) has a shape complementary to the shape of the at least one hole (4).

13. A solid cellulose foam product according to any one of the preceding claims, wherein the at least one base portion (2, 2') comprises at least one compressed region (3, 3') having a higher density than an uncompressed region (28) of the at least one base portion (2, 2').

14. A solid cellulose foam product according to claim 13, wherein the density of the uncompressed area of ​​the at least one base portion (2, 2') is in the range of 10-80 kg / m 3 , preferably 10-60kg / m 3 , and more preferably 20-50kg / m 3 within the range.

15. A solid cellulose foam product according to any one of claims 13 or 14, wherein the density of the at least one compressed area (3, 3') is 110% or greater, preferably 120% or greater, and more preferably 130% or greater, of the density of the uncompressed area (28) of the at least one base portion (2, 2').

16. A solid cellulose foam product according to any one of claims 13 to 15, wherein the at least one receiving chamber (5) comprises the at least one compressed area (3, 3').

17. A solid cellulose foam product according to any one of the preceding claims, wherein the density of the at least one plug (6) is higher than the density of the at least one base portion (2, 2').

18. A solid cellulose foam product according to any one of the preceding claims, wherein the density of the at least one plug (6) is 110% or more, preferably 120% or more, and more preferably 130% or more of the density of the at least one base portion (2, 2').

19. A solid cellulose foam product according to any one of the preceding claims, wherein the at least one base portion (2, 2') comprises at least one surface (21) comprising a densification layer.

20. A solid cellulose foam product according to claim 19, wherein the at least one compressed region (3, 3') of the at least one base portion (2, 2') comprises the densified layer.

21. A solid cellulose foam product according to any one of claims 19-20, wherein the at least one compressed region (3, 3') of the at least one receiving chamber (5) comprises the densification layer.

22. A solid cellulose foam product according to any one of claims 19 to 21, wherein the at least one plug (6) comprises at least one surface comprising a densified layer.

23. A solid cellulose foam product according to any one of the preceding claims, wherein at least one surface of the at least one receiving chamber (5) is arranged in direct contact with the protruding portion.

24. A solid cellulose foam product according to any one of the preceding claims 19-23, wherein said at least one surface of said at least one receiving chamber (5) arranged in said direct contact with said protruding portion comprises said densification layer.

25. A solid cellulose foam product according to any one of the preceding claims, wherein the at least one plug (6) arranged in the at least one hole (4) is further arranged to be in direct contact with the protruding portion within the receiving chamber (5).

26. A solid cellulose foam product according to 19-25, wherein the at least one plug (6) arranged in direct contact with the protruding portion is further arranged to contact the protruding portion through the at least one surface (61) comprising the densification layer.

27. A solid cellulose foam product according to any one of the preceding claims, wherein the at least one base portion (2, 2') and the at least one plug (6) comprise a cellulose foam composition comprising a) 71 to 95 wt% cellulose fibers, calculated on the total weight of the solids content of the composition; b) 4 to 24 wt% of a water-soluble thickener, based on the total weight of the solid content of the composition, and c) at least two surfactants.

28. A solid cellulose foam product according to any one of the preceding claims, wherein the cellulose foam compositions of the at least one base portion (2, 2') and the at least one plug (6) may be the same or different.

29. A solid cellulose foam product according to any one of the preceding claims, wherein the cellulose fibres are preferably selected from wood pulp; regenerated cellulose fibres; and plant fibres; preferably selected from softwood pulp, chemithermomechanical pulp (CTMP) and dissolving pulp or any combination thereof.

30. A method for producing a solid cellulose foam product as defined in claim 1, comprising the steps of: a) providing at least one base part (2, 2'); b) forming a receiving chamber (5) in the at least one base part (2, 2'), the receiving chamber (5) being arranged to receive a protruding part of an object; c) providing the at least one base part (2, 2') with at least one hole (4); d) Providing at least one plug (6) which is arranged to be introduced into the at least one hole (4).

31. The method of producing a solid cellulose foam product according to claim 30, wherein the forming step further comprises: step b1) carries out at least one cutting line of a predetermined cutting depth into at least one surface (21) of said at least one base part (2, 2'), wherein said at least one cutting line defines at least one pattern on said at least one surface (21), and preferably, Step b2) presses at least one pressing tool into at least one pattern of at least one surface (21) of at least one base part (2, 2'), thereby forming at least one compressed area (3, 3') of the base part; the at least one compressed area (3, 3') forms a receiving chamber (5), and the receiving chamber (5) is arranged to receive a protruding part of the object (O).

32. The method of claim 30 or 31, wherein the method further comprises: Two or more base parts (2, 2') are arranged to be firmly fixed to each other by a fixing device; the corresponding receiving chambers (5) of the two or more base parts (2, 2') face each other, thereby forming the receiving chamber (5) arranged to receive the protruding part of the object (O).

33. Method according to any one of claims 30 to 32, wherein the density of the at least one plug (6) is higher than the density of the at least one base part (2, 2').

34. Method according to claim 33, wherein the density of the at least one plug (6) is 110% or more, preferably 120% or more, and more preferably 130% or more of the density of the at least one base part (2, 2').

35. Method according to any one of claims 33-34, wherein said higher density of said at least one plug (6) is obtained by compressing said at least one plug (6) before carrying out step c).

36. Method according to any one of claims 30-35, wherein the method further comprises compressing the at least one plug (6) to a thickness of less than 90%, preferably less than 70%, and more preferably less than 50% of the initial uncompressed thickness of the at least one plug.

37. The method according to any one of claims 31 to 36, wherein step b1) further comprises arranging the at least one cutting line to partially cut through the thickness of the at least one base part (2, 2') so that the predetermined cutting depth is less than the thickness of the at least one base part (2, 2').

38. A method according to any one of claims 30-37, wherein the at least one base part (2, 2') and / or the at least one plug (6) comprises at least one surface (31, 61), the surface (31, 61) comprising a densification layer and the densification layer is arranged to be in direct contact with the protruding part.

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