FIELD OF THE INVENTION

The present invention relates to the area of cellulose foam for packaging, more specifically to a protective packaging insert comprising a substrate and a solid cellulose foam plank.

The invention further relates to a method for producing a protective packaging insert and a method for protecting a product by inserting said product in a protective packaging insert.

BACKGROUND INFORMATION

Plastic packaging materials such as fossil-based foams seem increasingly outdated in a society that is striving to reduce plastic usage and waste and move towards renewable materials. With regulatory bodies now driving policy towards limiting or banning fossilbased foam materials in packaging, new solutions are needed.

There are many challenges with finding foams from renewable sources. Many bio-based foams have higher cost of production and lower mechanical performance, as well as poor stability in water or high temperatures, compared to established foams from oilbased sources. Bio-based and recyclable protective materials need to have the same excellent characteristics and properties as petroleum-based protective materials for being the first choice over petroleum-based materials.

Low weight and good shock absorption of the bio-based foams are examples of crucial characteristics. Also, the ability to customize the shape and the form of the bio-based foam to the shape and form of the goods to be sheltered by the protective material is of uttermost importance. Cellulose has shown to have a special potential, as the most abundant renewable natural polymer on earth, with its crystalline structure, and the availability of methods for preparing large volumes on an industrial scale. Several biobased foams comprising cellulose have been described. W020200011587 Al describes a porous material that is prepared by aerating a paste comprising cellulose fibres and gluten and depositing the aerated paste in a mould where it is dried. WO2015036659 Al describes a moulded fibrous product prepared by foaming an aqueous suspension of natural fibres in combination with synthetic fibres and surfactant, feeding the fibrous foam to a mould where it is dried to produce a dry fibrous product.

The goods to be sheltered may often have protruding portions that need extra protection by the packaging material during storage and transportation. In addition, the goods may be made of sensitive materials such as glass, porcelain, that need protection because of their fragile nature. The bio-based foams on the market do not provide the necessary protection when the product receives constant corner or edge shock during the delivery cycle.

Thus, there still exists a need for solid cellulose foams that can be tailored around goods of any shape and protect every part of the goods. The goods have to be so well sheltered so that any shock arising during storage and transportation will be absorbed by the surrounding cellulose foam and whereby the shock will not damage the goods.

Further, the solid cellulose foams need to be renewable, biodegradable, and fully recyclable in regular paper and board flows allowing them to be part of a circular material flow in existing packaging waste management systems. Production costs of producing the foams as well as tailoring their shapes to any product shape have to be moderate in order to be a competitive choice.

In order to save raw materials there is also a need for reducing the amount of material in protective packaging inserts, as well as to minimize waste material.

There further exists a need for protective packaging materials that easily can be transported to places where goods are to be packed inside the protective packaging materials. The protective packaging materials need to offer three-dimensionally tailored protection of the goods but also take up as little space as possible during transport to the packaging locations.

SUMMARY OF THE INVENTION

It is an object of the present invention to obviate at least some of the disadvantages in the prior art and to provide a protective packaging insert comprising a substrate and a solid cellulose foam plank and a method for producing a protective packaging insert.

Thanks to the present invention as defined in claim 1, a protective packaging insert that is flat when not in use is provided. An advantage of a flat insert is that said insert takes up very little space when stored or during transport to the location of use. All parts of said insert are fixedly arranged, meaning that there are no loose parts that risk falling off or disappear.

Furthermore, the insert is easy to open/unfold and when the insert is open, the protective parts are already in place ready to receive a product to be protected by said insert.

All parts of said solid cellulose foam plank are fixedly arranged on a substrate that has low air permeability making it possible to use said protective packaging insert for vacuum suction and automatization, making the packaged product assembling more convenient and less time-consuming.

Another advantage is that the cushioning and sheltering material of said insert, i.e. said solid cellulose foam plank, may easily be tailored to any shape of the product to be protected and at a low cost.

By a combination of through-cuts and partial cuts of said solid cellulose foam plank, portions of said solid cellulose foam plank are provided that can be tailored around the product.

Sections of said substrate may be folded towards said product such that cut out portions of the solid cellulose foam plank come in a direct contact with said product. The very good cushioning ability of said solid cellulose foam plank efficiently shelters said product; said cut out portions fixedly arranged on said substrate help to position the product during insertion and give extra protection.

Thanks to compressing well defined portions of said solid cellulose foam plank to compressed materials of higher density, the stiffness and resilience of the solid cellulose foam plank is increased in those portions. This provides means for keeping the product in place within the protective packaging insert.

Yet an advantage is that no waste material is formed during the manufacture of said insert. Rather, all material and all parts of said solid cellulose foam plank are used through said tailoring of the plank to the shape of the product.

Said through-cuts creates through-going holes, the volume of which contribute to a housing for enclosing said product while partial cuts define surfaces which surfaces are then pressed whereby pressed regions are formed. Volumes of said compressed regions also contribute to said housing. Hence, arranging a housing in said solid cellulose foam plank causes no waste material.

Said partial cuts allow the product to be perfectly positioned and adds crucial extra protection in the packaging. Pressed details of said solid cellulose foam plank ensure correct positioning of the heaviest and/or most fragile parts of said product and ensures that they are kept in place.

Another advantage is that the present method for production is easy to perform in a large scale set up.

Further aspects and embodiments are defined in the appended claims, which are specifically incorporated herein by reference.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

The invention will be described in more detail with reference to the enclosed figures, in which:

Fig. 1 is an oblique side-view from above of a protective packaging insert that is not yet fully produced,

Fig. 2a-2c show different side-views of a fully produced protective packaging insert in an unfolded state, and

Fig. 3 shows a view oblique from above of a folded protective packaging insert.

DETAILED AND EXEMPLIFYING DESCRIPTION OF THE INVENTION

Before the invention is disclosed and described in detail, it is to be understood that this invention is not limited to particular compounds, configurations, method steps, substrates, and materials disclosed herein as such compounds, configurations, method steps, substrates, and materials may vary somewhat. It is also to be understood that the terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting since the scope of the present invention is limited only by the appended claims and equivalents thereof.

It must be noted that, as used in this specification and the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

If nothing else is defined, any terms and scientific terminology used herein are intended to have the meanings commonly understood by those of skill in the art to which this invention pertains. The term "about" as used in connection with a numerical value throughout the description and the claims denotes an interval of accuracy, familiar and acceptable to a person skilled in the art. Said interval is ± 10 %.

The expression “fixedly arranged” as used herein denotes arranging a subject to another subject such that said subjects are fixed to each other in a non-detachable manner.

The expression “folding line separates a ...” as used herein means that a fold line divides a flat surface into two parts whereby the two parts can easily be folded in relation to each other so that they form an angle to each other. Said parts separated by the folding line is still connected to each other and as they were before arranging the folding line. The folding line only facilitates the folding and also that the folding occurs at a desired position.

The expression “flat” as used herein means an object having a height, a width and a length. Said width and length defining two surfaces and said height defining at least one side wall. Said height is so small in relation to said length and width that said object is related to as a flat object. Examples of flat objects are planks, tabletops, wall mirrors, door leaves, glass panes, solar panels. The expression “flat” refers to an object having a level surface without any protrusions or indentations. Thus, when in a folded state, the top and bottom surfaces of the protective packaging insert of the present invention are flat, such that there are no protruding portions of the packaging insert.

The expressions ”at least one removably arranged portion of said solid cellulose foam plank” and “at least one second portion of said solid cellulose foam plank” are used interchangeably in the following text and refer to the same portion of said solid cellulose plank.

The expressions “remaining portion of said solid cellulose foam plank” and “a first portion of said solid cellulose foam plank” are used interchangeably in the following text and refer to the same portion of said solid cellulose foam plank. The term “foam”, as used herein, refers to a substance made by trapping air or gas bubbles inside a solid or liquid. Typically, the volume of gas is much larger than that of the liquid or solid, with thin films separating gas pockets. Three requirements must be met in order for foam to form. Mechanical work is needed to increase the surface area. This can occur by agitation, dispersing a large volume of gas into a liquid, or injecting a gas into a liquid. The second requirement is that a foam forming agent, typically an amphiphilic substance, a surfactant or surface active component, must be present to decrease surface tension. Finally, the foam must form more quickly than it breaks down.

The term “cellulose foam”, as used herein, 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. Cellulose is in the form of fibres, and the foam can thus also be defined to be a fibrous foam or a cellulose fibre foam. The cellulose foam may be wet or solid.

The term “wet foam”, or “wet cellulose foam”, as used herein, 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 freestanding 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 thus be freestanding, unless a large enough force is applied so that it starts to flow and instead behave as a viscous material. Depending on the magnitude and timescale of any applied shear stress, the wet foam can show a predominantly viscous or elastic behaviour.

The term “solid cellulose foam”, or “dry cellulose foam”, as used herein, refers to a dry porous cellulose material that has been formed from a wet cellulose foam, i.e. a foam formed material. During the drying process, a closed wet cellulose foam is transformed into an open solid cellulose foam. The network of cellulose fibres is prevented from collapsing during drying. The solid cellulose foam will as a result have a shape that to a large extent corresponds to that of the wet cellulose foam. The dry content of the solid cellulose foam may be at least 95 wt% as calculated based on the total weight of the solid cellulose foam. The shape and density of the solid cellulose foam is retained also in a non-confined state. The solid cellulose foam has an open cell structure, allowing air to occupy the pores within the foam. The solid cellulose foam can also be described as a porous material or a low-density material.

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

In a first aspect, the present invention provides a protective packaging insert.

In a second aspect, the present invention relates to a method for producing a protective packaging insert comprising a substrate and a solid cellulose foam material.

In a third aspect, the present invention relates to a method for protecting a product by inserting said product in a protective packaging insert.

Said solid cellulose foam plank may preferably be prepared from a cellulose foam composition comprising: a) from 71-95 wt% cellulose fibres, as calculated on the total weight of solid content of the composition, b) from 4-24 wt% of a water-soluble thickener, as calculated on a total weight of solid content of the composition, and c) at least two surfactants.

Cellulose fibres suitable for use in the present invention can originate from wood, such as softwood or hardwood, from leaves or from fibre crops (including cotton, flax and hemp). The cellulose fibres suitable for use in the present invention can also originate from regenerated cellulose such as rayon and Lyocell. The cellulose fibres suitable for use in the present invention may include lignin or hemicellulose or both, or the cellulose fibres may be free from lignin and hemicellulose. Preferably, the cellulose fibres originate from wood, more preferably the cellulose fibres are pulp fibres obtained by pulping processes which liberates the fibres from the wood matrix. Pulp fibres can be liberated by mechanical pulping, obtaining mechanical pulp such as thermos mechanical pulp (TMP) or chemo thermos mechanical pulp (CTMP), or by chemical pulping such as Kraft pulp or pulps obtained by the sulphite process, soda process or organosolv pulping process. More preferably, the cellulose fibres are pulp fibres liberated by chemical pulping processes. The different characteristic of each cellulose fibre will affect the properties of the final cellulose foam. A cellulose fibre is significantly longer than it is wide. Cellulose fibres can have a mean width of 0.01 to 0.05 mm. The fibre length of softwood can be from 2.5 to 4.5 mm, while hardwood can have a fibre length from 0.7 to 1.6 mm, and Eucalyptus from 0.7 to 1.5 mm. However, the fibre length can vary considerably with different growing place etc. The cellulose fibres in the cellulose foam disclosed herein can have a length from 0.1 mm to 65 mm, or from 0.1 mm to 10 mm, or from 0.5 mm to 65 mm, or from 0.5 mm to 10 mm, or from 0.5 mm to 7 mm. The fibre lengths may provide different mechanical characteristics to the foam. Due to the length of fibres, they can entangle with each other and impart fibre to fibre interbonds that bring strength to the foam. The aspect ratio, i.e. the ratio of the fibre length to the fibre width, of the cellulose fibres 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 for preservation and stabilization of the foam structure during the drying procedure, making it possible to dry the wet cellulose foam with retained shape. The aspect ratio can be up to 6500, or preferably up to 2000.

The cellulose fibres may be modified to provide different properties to the final cellulose foam. For example, phosphorylated fibres or periodate oxidized fibres could also be used when producing a cellulose foam according to the present invention.

The cellulose fibres of the cellulose foam composition may be selected from wood pulp; regenerated cellulose fibres; and plant fibres, such as fibres from bamboo, cotton, hemp, flax, and jute.

Preferably, the cellulose fibres are selected from wood pulp, such as softwood pulp, hardwood pulp, chemi-thermo mechanical pulp, and from dissolving pulp, or a combination of one or more of these.

More preferred, the cellulose pulp fibres are selected from softwood pulp, chemi-thermo mechanical pulp, or dissolving pulp.

Most preferred, the cellulose pulp fibres are selected from softwood pulp, such as softwood kraft bleached pulp.

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

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 during preparation of the foam quickly settle at the air-water interphase during mechanical agitation, which contributes to the formation of a foam with a high density and a high viscosity and thus enables a free-standing foam. A suitable surfactant for this purpose is an anionic surfactant, preferably a low-molecular weight anionic surfactant. The low-molecular weight anionic surfactant may be selected from sodium dodecyl sulphate (SDS); potassium dodecyl sulphate, sodium laureth sulphate (SLES); sodium dodecylbenzenesulphonate; sodium cocoyl sarcosinate; sodium lauroyl sarcosinate. The low-molecular weight anionic surfactant is preferably selected from sodium dodecyl sulphate (SDS); sodium p-n-dodecylbenzenesulphonate; 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.

The other one of the at least two surfactants is preferably a co-surfactant. The cosurfactant may be selected from high pKa fatty acids, such as from plant derived feedstock, e.g. tetradecanoic acid (myristic acid), sodium oleate, lauric acid, palmitic acid, and stearic acid; glucose based cosurfactants with an aliphatic carbon tail, such as alkyl glycosides, alkylpolyglucosides, alkyl thio-glycosides, and alkyl maltosides; amphoteric betaines, such as cocamidopropyl betaine (CAPB), and sodium cocoiminodipropionate (CADP); polyethylene glycol sorbitan monolaurate, i.e. tween® (e.g. tween® 20, tween® 80 and tween® 85); and polyoxyethylene lauryl ethers, such as polyethylene glycol dodecyl ether, pentaethylene glycol monododecyl ether and octaethylene glycol monododecyl ether.

Said foam composition may preferably be prepared by a method comprising the steps of: a) disintegrating cellulose fibres in water to obtain a slurry of cellulose fibres; b) adding the thickener to the slurry obtained in a) to obtain a mixture of thickener and cellulose fibres in water; c) adding the at least two surfactants to the mixture obtained in b) to obtain a fibre suspension; d) aerating the suspension obtained in c) to obtain a wet foam, wherein the wet foam comprises 10-38 wt% cellulose fibres, 0.5-10 wt% of the water-soluble thickener, and 0.1-2 wt% surfactants, as calculated on the total weight of the wet foam, and wherein the wet foam has a density of from MO- SOO kg/m3 and a yield stress of from 40 to 400 Pa; e) drying the wet foam obtained in d) to obtain a dried cellulose foam.

The wet foam may be dried without using a mould, i.e. the wet foam is free-standing and retains its shape during drying without the need of a mould.

The wet foam is homogenous and has a good stability due to a small bubble size (typically below 100 pm) obtained when aerating the mixture of cellulose fibres, thickener and surfactants. The wet foam does not flocculate during processing. The average bubble size is largely maintained during any subsequent processing or drying steps and the cellulose fibres remain well dispersed. The resulting solid cellulose foam obtained by drying the wet foam will be homogenous in structure, strong, have good mechanical properties, a smooth surface and no defects. Since the foam has a smooth surface, it can easily be attached to e.g. a substrate. In comparison, a wet cellulose foam with low stability has a larger average bubble size (i.e. typically above 100 pm) and the bubbles will coalesce faster during processing and drying such that larger bubbles are formed. In addition, the cellulose fibres will form clusters during processing and drying. This results in the wet foam collapsing during drying. The resulting solid cellulose foam will not have a homogenous structure and will also contain defects in the form of cavities resulting from the coalesced bubbles in the wet foam. Such a solid cellulose foam is, due to the defects, weak and has a rough surface.

Said dried cellulose foam obtained in step e) may be used as the solid cellulose foam plank.

Said dried cellulose foam obtained in step e) may be obtained by a method comprising: depositing discrete units of a foam on a surface to obtain a first foam deposition, depositing a wet foam between the discrete units to obtain a subsequent foam deposition, and drying the wet foam to obtain a solid foam wherein discrete units of a foam are embedded in a foam matrix. Said solid foam may then be used as the solid cellulose foam plank of claim 1 and its dependent claims.

However, said solid cellulose foam plank may be prepared by other methods than the above described without departing from the scope of the present invention. For example, said solid cellulose foam plank may be prepared by a single deposition of a wet foam into any desired shape. Optionally, any suitable restriction means, such as a mould or a frame, may be used.

Said solid cellulose foam plank may e.g. be prepared by depositing the foam composition on a forming portion of a conventional or, for the purpose suitably modified, paper machine for forming a foam web. Said solid cellulose foam is preferably not a memory foam going back to its original shape, rather said foam stays in its compressed shape, since the open-cell structure of the bulk of said foam is deformed during compression.

An example of a conceivable dimension is a solid cellulose foam plank having a thickness of in the range of from 1 to 20 cm, or from 1 to 10 cm, or from 1 to 5 cm, or from 4 to 6 cm. A preferred thickness is about 5 cm. Said at least one base portion may be cut from such a plank and said thickness of the plank may preferably correspond to a width of said back surface 23 of said at least one base portion.

Said dimensions only serve as examples and should not be seen as limiting the inventive product to said dimensions.

Production of a solid cellulose foam comprises different production steps, one of which is a drying step. During said drying step outside surfaces of said foam (top surface, bottom surface, side surfaces) will get an outer layer that has different properties than a bulk portion of said foam comprising a more homogeneous and open-cell porous fibre network. Said outer layer has a higher density than a density of said bulk portion because the fibres are packed more tightly and are partly oriented differently. The outer layer is called a "densified layer". Said densified layer will provide improved mechanical stability and improved strength to the foam.

Thanks to said densified layer having improved mechanical stability and providing strength to said foam, it is preferred to orientate surfaces comprising said densified layer towards directions where extra shock absorption may be needed. The improved properties of said densified layer are used at positions of the product where they can contribute to the protective properties of said product.

Although having a higher density, said densified layer is still highly porous and air permeable.

Said first aspect, said protective packaging insert, is now to be described in detail. In Fig. 1 said protective packaging insert 1 comprising a substrate 2 and a solid cellulose foam plank 3 is shown.

Said substrate 2 is a flat substrate comprising a top surface 21, a bottom surface 22 and a width w2, i.e. a length of a short side of said substrate 2.

Said substrate 2 comprises at least two sections 23, 25 and at least one folding line FL3 separating said at least two sections 23, 25 wherein said at least one folding line FL3 is arranged to allow said substrate 2 to be folded into a folded state.

In Fig. 1, said substrate 2 comprises three sections 23, 24, 25 separated by two folding lines FL2, FL3. Said three sections are a first section 25, a second section 23 and a third section 24.

Said second section 23 comprises three portions, namely a first portion 23a, a second portion 23b, and a third portion 23c.

Said first portion 23a of said second section 23 comprises a surface 231a.

Said second portion 23b of said second section 23 comprises a surface 231b.

Said third portion 23c of said second section 23 comprises a surface 231c.

Said surfaces 231a, 231b, 231c of said three portions 23a, 23b, 23c are part of said top surface 21 of said substrate 2.

A folding line FL4 separates said second section into said first portion 23 a and said second portion 23b, and another folding line FL5 separates said second section further into said second portion 23b and said third portion 23c. A hole 20 is arranged on said folding line FL5 separating said second portion 23b and said third portion 23c and centred on said folding line FL5.

Said third section 24 comprises two portions, namely a first portion 24a and a second portion 24b.

Said first portion 24a of said third section 24 comprises a surface 241a.

Said second portion 24b of said third section 24 comprises a surface 241b.

Said surfaces 431a, 241b of said two portions 24a, 24b are part of said top surface 21 of said substrate 2.

A folding line FL1 separates said third section 24 into said first portion 24a and said second portion 24b.

A total length of said substrate is a sum of sub-lengths for said sections and portions of sections, i.e. a sum of 123c, 123b, 123a, 122, 124a and 124b (see Fig. 2c).

As shown in Fig. 1 said top surface 21 of said substrate 2 is arranged with said solid cellulose foam plank 3.

Solid cellulose foam plank 3 comprises an upper surface 31, a bottom surface 32, two long side surfaces 33 having a length 13, and two short side surfaces 34 having a width w3.

Said upper surface 31 and said bottom surface 32 are flat surfaces.

Said bottom surface 32 of said plank 3 is arranged on said top surface 21 of said substrate 2. Said width w3 of said short side surfaces 34 of said plank 3 corresponds to said width w2 of said substrate 2.

A length 122 (shown in Fig. 2c) of said first section 25 of said substrate 2 corresponds to a length 13 of said long side surfaces 33 of said plank 3.

Said long side surfaces 33 have a height h3. Said height h3 corresponds to a thickness x3 of said plank 3.

Said upper surface 31 of said plank 3 comprises at least one cutting line 4 of a predetermined cutting depth DC (see Fig. 2a).

Said at least one cutting-line 4 is arranged on said upper surface 31 of said solid cellulose foam plank 3 thereby defining a first portion 36 and at least one second portion 35 (see figs. 2a-2c) of said solid cellulose foam plank 3.

Said at least one cutting line 4 defines at least one pattern 6 on said upper surface 31 of said plank 3.

Said at least one pattern 6 defines said at least one second portion 35 comprising an upper surface 351 and said first portion 36 comprising an upper surface 361.

Said at least one second portion 35 of said plank 3 is arranged to be a at least one removably arranged portion 35 having an upper surface 351.

In Fig. 1 it is shown that said at least one second portion 35 of said plank 3, i.e. said at least one removably arranged portion 35 of said plank 3, comprises four second portions 35a, 35b, 35c, 35d. Each of said four second portions 35a, 35b, 35c, 35d comprises an upper surface 351a, 351b, 351c, 35 Id, respectively. Two second portions of said at least one second portion 35 form a first pair of removably arranged portions 35a, 35b and two other second portions of said at least one second portion 35 form a second pair of removably arranged portions 35c, 35d.

It is to be understood that said first portion 36 is a remaining portion 36 of said plank 3 after cutting out said at least one second portion 35.

Figs. 2a-2c are side-views of said protective packaging insert 1, which will now be described in detail.

A bottom surface of said first portion 36 of said solid cellulose foam plank 3 is fixedly arranged on said top surface 251 of said first section 25 of said substrate 2.

According to the invention said upper surface 351 of said at least one second portion 35 of said solid cellulose foam plank 3 is fixedly arranged on a top surface 231b, 241b of at least one second section 23, 24 of said substrate 2.

Said upper surfaces 351a, 351b of said first pair 35a, 35b of said at least one removably arranged portion 35 of said solid cellulose foam plank 3 are fixedly arranged on said top surface 241b of said second portion 24b of said third section 24 of said substrate 2.

Said upper surfaces 351c, 35 Id of said second pair 35c, 35d of said at least one removably arranged portion 35 of said solid cellulose foam plank 3 are fixedly arranged on said top surface 23 lb of said second portion 23b of said second section 23 of said substrate 2.

Said first portion 36 of said solid cellulose foam plank 3 comprises at least one through- going hole 38.

In Figs. 2a-2c, it is shown that said first portion 36 comprises two through-going holes 381, 382; a first through-going hole 381 and a second through-going hole 382 of said first portion 36. Said through-going holes 381, 382 expose portions of said top surface 251 of said first section 25 of said substrate 2.

Said at least one second portion 35 arranged to be said at least one removably arranged portion 35 has a shape corresponding to a shape of said at least one through-going hole 38. The corresponding shapes of said at least one removably arranged portion 35 and said at least one through-going hole 38 is of course due to said at least one second portion 35 being a cut out portion of said plank 3 thereby causing said at least one through-going hole 38.

Said first pair of removably arranged portions 35a, 35b and said second pair of removably arranged portions 35c, 35d all have shapes that fit into said through-going holes 381, 382.

Two second portions 35a, 35c of said four second portions fit into said first through- going hole 381; while two other second portions 35b, 35d fit into said second through- going hole 382.

In Figs. 2a-2c, it is further shown that said protective packaging insert 1 comprises at least one housing 5 arranged to house a product to be protected.

Said at least one housing 5 arranged to house a product to be protected is comprised in said solid cellulose foam plank 3.

Said at least one housing 5 comprised in said plank 3 is preferably formed by said at least one through-going hole 38 and at least one compressed region 37 comprised in said first portion 36 of said plank 3. By forming said housing 5 by said at least one through-going hole 38 in combination with at least one compressed region 37, fewer cut-outs are needed in the plank 3. This enables a stronger protective packaging insert. The material waste is also reduced since no material is cut out and discarded in order to form a housing. By the housing 5 comprising at least one compressed region 37, the strength of the housing 5 is increased due to the increased density of the compressed region 37. This is of particular importance when heavy objects are to be protected.

Said at least one housing of said first portion 36 comprises a depth and is arranged in said upper surface 31 of said first portion and in a direction from said upper surface 31 towards said bottom surface of said first portion 36 of said plank 3. Said depth may be smaller than said thickness x3 of said plank.

Said at least one housing 5 further comprises a depth equal to said thickness x3 of said plank 3 and corresponding to said at least one through-going hole 38. Preferably, at least one portion of said at least one housing 5 is arranged by pressing a pressing tool into a surface of at least one pattern 6 on said upper surface 31 of said first portion 36 and/or by pressing said product to be protected by said protective packaging insert into said surface of at least one pattern 6 on said upper surface 31 of said first portion 36.

Said at least one compressed region 37 is now to be described.

In Figs. 2a-2c there is shown two compressed regions 37, 377 With reference mainly to Fig. 2a, said two compressed regions 37, 37' are comprised in said plank 3 and more specific in said first portion 36 of said plank 3.

It is to be understood that said compressed regions 37, 37 'are arranged after removal of said at least one removably arranged portion 35a-35d out of and away from said plank 3. Said removal of said at least one removably arranged portion 35a-35d is performed in a direction from said bottom surface 32 of said plank 3 towards said upper surface 31 of said plank 3.

Said compressed regions 37, 37' are arranged by compressing a surface of said first portion 36 of said plank 3. However, said compression is preceded by first arranging at least one cutting line 4 of a predetermined cutting depth (DC) on a surface of said plank 3. Said at least one cutting line is arranged on an upper surface 31 of said first portion 36 of said solid cellulose foam plank 3 and into said surface 31. Said at least one cutting line 4 thereby defines said at least one pattern 6 on said upper surface 31 of said first portion 36.

Said at least one cutting line 4 is further arranged to partially cut through said thickness of said cellulose foam plank 3 such that said predetermined depth of cut DC is less than said thickness x3 of said cellulose foam plank 3.

Said predetermined depth of cut DC of said at least one cutting line 4 is 90% or less of said thickness x3 of said cellulose foam plank 3, preferably 70% or less and more preferred 60% or less.

Said compressing is then performed by pressing at least one pressing tool into said at least one pattern 6 of said upper surface 31 of said cellulose foam plank 3 thereby forming said compressed regions 37, 37' such that said compressed region 37, 37' form said at least one housing 5.

In some embodiments said product to be protected by said protective packaging insert may be said pressing tool. In such embodiments, no prior pressing is required. Thus, a more efficient process is enabled since a separate pressing step can be omitted.

In other embodiments said pressing may be performed by a pressing tool compressing said upper surface 31 of said cellulose foam plank 3 into a certain depth followed by further pressing by said product to be protected when said product is inserted in said compressed regions 37, 37'.

A first compressed region 37 comprises a compressed material 372 having a compressed thickness x372 and an upper surface 371. A second compressed region 37' comprises a compressed material 372' having a compressed thickness x372' and an upper surface 371 '.

Said thicknesses x372, x372' of said compressed materials 372, 372' may be equal or different. In Figs. 2a-2c it is shown that said thickness x372 of said compressed material 372 said first compressed region 37 is greater than said thickness x372' of said compressed material 372' of said second compressed region 37'.

It is to be understood that different thicknesses comply with different densities.

A smaller thickness corresponds to a higher density meaning that a density of said compressed material 372' of said second compressed region 37' is higher than a density of said compressed material 372 said first compressed region 37.

It is further shown that a shape of said upper surface 371 of said first compressed region 371 is different from a shape of said upper surface 371' of said second compressed region 37'.

A density of said compressed materials 372, 372' is preferably 10-90% higher than a density of said solid cellulose foam plank 3, more preferred 20-90% and most preferred 40-90%.

Said protective packaging insert 1 may be in a folded state or an unfolded state.

When said protective packaging insert 1 is in said folded state said insert 1 has a flat shape of a minimum volume.

It is a state of said substrate 2 that determines said state of said insert 1.

When said substrate 2 is folded around said plank 3, said insert 1 is in a folded state FS. In said folded state of said substrate 1, said at least one second portion 35 of said solid cellulose foam plank 3 is arranged in said at least one though-going hole 38 of said first portion 36 of said solid cellulose foam plank 3.

Said at least one folding line facilitates said folding an unfolding.

In Fig. 3 said folded state FS of said insert 1 is shown. Said four removably arranged portions (i.e. said four second portions) 35a-35d are arranged in said corresponding through-holes 381, 382. In said folded state, said insert 1 is flat.

Two second portions 35a, 35c of said four second portions are arranged in said first through-going hole 381; while two other second portions 35b, 35d are arranged in said second through-going hole 382.

Said substrate 2 is in said folded state in a tight relation to said plank 3. Each section 23, 24, 25 of said substrate 2 are in contact with a respective surface of said plank 3.

Said top surface 251 of said first section 25 of said substrate 2 is fixedly arranged to said bottom surface of said first portion 36 of said plank 3.

Said top surface 241a of said first portion 24a of said second section 24 is in contact with one of said short side surfaces 34 of said plank 6.

Said top surface 231a of said first portion 23a of said second section 23 is in contact with the other one of said short side surfaces 34 of said plank 6.

Said top surface 241b of said second portion 24b of said second section 24 is in contact with said upper surface 31 of said plank 6.

Said top surface 23 lb of said second portion 23b of said second section 23 is in contact with said upper surface 31 of said plank 6. Said third portion 23c of said third section 23 is overlapping said second portion 24b of said second section 24 such that said top surface 231c of said third portion 23c is in contact with a bottom surface of said second portion 24b of said second section 24.

Said hole 20 arranged on said folding line FL5 separating said second portion 23b and said third portion 23c provides a handle for easy opening of the folded insert.

Bottom surfaces of said four second portions 35a-35d are in contact with said top surface 251 of said first section 25.

In the embodiment shown in Fig. 3, a step of pressing into said surface of said at least one pattern 6 has not been performed. Rather, in this embodiment it is the product itself that will be said pressing tool. A surface of said product is positioned such that said surface faces said surface of said at least one pattern 6. Said product is then pressed into said surface of said at least one pattern 6 and into said plank 3 thereby at the same time compressing said plank and creating at least one compressed region 37, 372

Since said surface of said pattern 6 has not yet been pressed into said plank 6 said top surface 23 lb of said second portion 23b of said second section 23 and said top surface 241b of said second portion 24b of said third section 24 are further in contact with said upper surface 361 of said first portion 36 of said plank 3.

Figs. 2a-2c show the protective packaging insert in said unfolded state ready for insertion of a product to be protected.

Said insert 1 is arranged to house a first part of the product to be protected in said at least one housing 5 of said first portion 36 of said solid cellulose foam plank 3, wherein said at least one second portion 35 of said solid cellulose foam plank 3 is arranged to keep a second part of said product in place in said insert 1 and to protect said second part of said product when said at least one second section is folded towards said product and said at least one second portion 35 of said solid cellulose foam plank 3 is arranged to enclose said second part of said product. A whole of said product is now protected by said insert 1.

It is to be understood that said insert 1 is arranged to have a shape corresponding to a shape of said product when said product is arranged inside of said insert 1 and said at least one second section is folded against said product.

Said second aspect, the method for producing said protective packaging insert 1 comprising a substrate 2 and a solid cellulose foam material 3, is now to be described.

Said method for producing a protective packaging insert 1 comprises the steps of: a) providing a solid cellulose foam plank 3; b) arranging at least one portion 35 of said solid cellulose foam plank 3 to be at least one removably arranged portion 35 of said solid cellulose foam plank 3 thereby dividing said cellulose foam plank 3 provided in step a) into a remaining portion 36 (also termed a first portion of said solid cellulose plank 3 in the description of said first aspect of the invention) and said at least one removably arranged portion 35 (also termed a second portion in the description of said first aspect of the invention); c) providing a substrate 2 comprising at least two sections 23, 24, 25 and at least one folding line FL1-FL5; d) fixedly arranging a bottom surface 362 of said remaining portion 36 of said solid cellulose foam plank 3 on a top surface 251 of a first section 25 of said substrate 2 by a fixing means, and e) fixedly arranging an upper surface 351 of said at least one removably arranged portion 35 of said solid cellulose foam plank 3 to a top surface 231b, 241b of a second section 23b, 24b of said at least two sections of said substrate 2 by said fixing means.

Said method further comprises folding said second section 23, 24 of said at least two sections 23, 24, 25 of said substrate 2 around said at least one folding line FL1-FL4 such that said top surface 231b, 241b of said second section 23, 24 comes in a position near said upper surface 351 of said at least one removably arranged portion 35 of said solid cellulose foam plank 3 before fixedly arranging said upper surface 351 of said at least one removably arranged portion 35 to said top surface 231b, 241b of said second section 23, 24.

A preferred embodiment is now to be described. Said preferred embodiment is a method for producing said protective packaging insert 1 as described above and with reference to Figs 1-3.

Said solid cellulose foam plank 3 is provided in step a). Said plank 3 is flat and dimensions of said plank 3 are chosen based on dimensions of the product to be enclosed and protected.

Step b) comprises arranging four portions 35 of said solid cellulose foam plank 3 to be four removably arranged portions 35a-35d of said solid cellulose foam plank 3 thereby dividing said cellulose foam plank 3 provided in step a) into said remaining portion 36 and said four removably arranged portions 35a-35d.

In step c) said substrate 2 is provided. Said substrate comprises three sections 23, 24, 25 and at least two folding lines separating said three sections 23, 24, 25. Said folding line FL2 separates said first 25 and said third section 24 and said folding line FL3 separates said first section 25 and said second section 23.

In said preferred embodiment as much as five folding lines FL1-FL5 are arranged and as disclosed in relation to said first aspect of the invention.

Step d) comprises fixedly arranging said bottom surface of said remaining portion 36 of said solid cellulose foam plank 3 on said top surface 251 of said first section 25 of said substrate 2 by a fixing means.

Step e) comprises fixedly arranging upper surfaces 35 la-35 Id of said four removably arranged portions 35a-35d of said solid cellulose foam plank 3 to a top surface 231b, 241b of a second section 23b, 24b of said at least two sections of said substrate 2 by said fixing means. Said fixing means may be a glue, preferably a bio-based glue.

Said four removably arranged portions 35a-35d of said solid cellulose foam plank 3 are arranged to be removable from said upper surface 31 of said solid cellulose foam plank

3.

Said method further comprises providing at least one cutting line 4 of a predetermined depth of cut DC into a surface of said solid cellulose foam plank 3, whereby said at least one cutting line 4 defining at least one pattern 6 on said surface of said solid cellulose foam plank 3.

In Fig. 1 it is shown that said at least one cutting line 4 comprises several cutting lines

4. Said several cutting line s4 preferably have different predetermined depths of cut DC.

Said cutting lines 4 are provided into said upper surface 31 of said solid cellulose foam plank 3.

At least one cutting line 4 is arranged to cut through a thickness of said cellulose foam plank 3 such that said predetermined depth of cut DC is equal to said thickness x3 of said cellulose foam plank 3, thereby arranging said four portions of said solid cellulose foam plank 3 to be said four removably arranged portions of said solid cellulose foam plank 3.

At least one cutting line 4 is arranged to partially cut through said thickness x3 of said cellulose foam plank 3 such that said predetermined depth of cut DC is less than said thickness of said cellulose foam plank 3.

For said at least one cutting line 4 arranged to partially cut through said thickness x3 of said plank 3, said predetermined depth of cut DC of said at least one cutting line is 90% or less of said thickness x3 of said cellulose foam plank 3, preferably 70% or less and more preferred 60% or less. Said method further comprises a pressing step. At least one pressing tool is pressed into said at least one pattern 6 of said upper surface 31 of said cellulose foam plank 3 and/or by pressing a product to be protected by said protective packaging insert.

Said at least one pressing tool preferably has a pressing area that corresponds to or is smaller than an area of the at least one pattern 6 of said upper surface 31 of said cellulose foam plank 3.

Said pressing is preferably performed without heating said at least one pressing tool and said cellulose foam plank.

Two compressed regions 37, 37' are thereby formed; said two compressed regions 37, 37' forming said at least one housing 5.

A depth of said at least one housing 5 is less than said thickness x3 of said solid cellulose foam plank 3.

Said method further comprises folding said first portion 23a and said second portion 23b of said second section 23 around folding lines FL3, FL4 and said first portion 24 a and said second portion 24b of said third section 24 of said substrate 2 around folding lines FL1, FL2, such that said top surface 231b, 241b of respective said second and third section 23, 24 come in a position near said upper surfaces 35 la-35 Id of said four removably arranged portions 35 of said solid cellulose foam plank 3, followed by fixedly arranging said upper surfaces 35 la-35 Id of said four removably arranged portions 35 to said top surface 231b, 241b of respective said second and third section 23, 24.

Said upper surfaces 351a, 351b of said first pair 35a, 35b of said four removably arranged portions 35 of said solid cellulose foam plank 3 are fixedly arranged on said top surface 241b of said second portion 24b of said third section 24 of said substrate 2. Said upper surfaces 351c, 35 Id of said second pair 35c, 35d of said at least one removably arranged portion 35 of said solid cellulose foam plank 3 are fixedly arranged on said top surface 23 lb of said second portion 23b of said second section 23 of said substrate 2.

Said at least one removably arranged portion 35 - said four removably arranged portions 35a-35d of said preferred embodiment - is fixedly arranged on said top surface 21 of said substrate 2.

Said at least one removably arranged portion 35 (said four removably arranged portions 35a-35d of said preferred embodiment) is further arranged to be removable from said at least one through-going hole 38 (said two through-going holes 381, 382 in said preferred embodiment) of said remaining portion 36 of said plank 36, i.e. said first portion 36 of said plank 3.

Said at least one removably arranged portion 35 is arranged to be removed from said at least one through-going hole 38 and to be reintroduced into said at least one through- going hole 38.

Said at least one removably arranged portion 35 is further fixedly arranged to said top surface 21 of said substrate 2.

When said at least one removably arranged portion 35 is arranged in said at least one through-going hole 38, said substrate 2 is closely enclosing said plank 3. Said insert 1 is in its folded state FS and having said flat shape.

Said protective packaging insert 1 has now been produced by said method.

Said protective packaging insert 1 is ready to be sent to a producer of said product for protectively packing said product in said protective packaging insert 1. Said third aspect of the invention, i.e. the method for protecting a product by inserting said product in a protective packaging insert, is now to be described.

Said method comprises the steps of: a) Providing said protective packaging insert 1, preferably in said folded state FS; b) Unfolding said second section 23, 24 of said substrate 2 of said protective packaging insert 1 from a folded state into an open state, whereby exposing said first portion 36 of said solid cellulose foam plank 3 and said at least one second portion 35 of said solid cellulose foam plank 3; c) Inserting a product to be protected in said at least one housing 5 comprised in said first portion 36; whereby said at least one housing 5 enclosing a first part of said product; d) Folding said second section 23, 24 towards said product such that said at least one said second portion 23, 24 of said solid cellulose foam plank 3 enclosing a second part of said product; whereby a whole of said product is protected, and preferably followed by e) Inserting said protective packaging insert comprising said protected product in an enclosing packaging.

In a preferred embodiment of said method for protecting a product, said method further comprises:

Grabbing a handle arranged on said insert 1. In the preferred embodiment said hole 20 is arranged to be said handle. It is however conceivable to arrange said handle in other ways without departing from the scope of the present invention.

By grabbing the hole 20, said second section 23 of said substrate 2 may be moved from the close enclosing of said plank 3. When said second section 23 is moved, said second pair of removably arranged portions 35c, 35d are removed from said through-going holes 381, 382. Said second portion 23b of said second section 23 is unfolded around said folding line FL4 and said first portion 23a of said second section 23 is unfolded around said folding line FL3. Next step is to grab said third section 24. This section may also be provided with some kind of handle, e.g. a hole. Said second portion 24b of said third section 24 is moved from its close enclosing of said plank 3. When said third section 24 is moved, said first pair of removably arranged portions 35a, 35b are removed from said through-going holes 381, 382. Said second portion 24b of said second section 24 is unfolded around said folding line FL1 and said first portion 24a of said second section 24 is unfolded around said folding line FL2.

Both first pair 35a, 35b and second pair 35c, 35d are removed from said through-going holes 381, 382. Said insert 1 is now in its unfolded state and ready to receive said product to be protected.

Said product to be protected is inserted into said insert 1 such that a surface of the product is placed in said at least one housing 5 of said remaining (first) portion 36.

In the embodiment shown in Fig. 3 there is no housing 5 yet. Said plank 3 comprises at least one cutting line 4 having a predetermined depth of cut DC that is smaller than said thickness x3 of said plank 3. Said surface of said product is positioned such that said surface of said product contacts said surface said pattern 6 defined by said at least one cutting line 4. A pressure is applied to the product thereby causing said surface of said product to be pressed into a core of said plank thereby creating said compressed region 37, 37' and said housing 5.

After said product is positioned in and enclosed by said at least one housing 5, said third section 24 is folded around its folding lines FL1, FL2 towards said product. Said first pair 35a, 35b comes in a direct contact with a part of said second portion of said product. Said part of said second portion of said product will be firmly held in place by said first pair 35a, 35b of removably arranged portions 35 of said solid cellulose foam plank 3. Said first pair further protects said part of said second portion due to the cushioning properties of said cellulose foam material of the plank 3.

Said folding of said third section 24 is followed by folding of said second section 23. Said second section 23 is folded around its folding lines FL3, FL4 towards said product. Said second pair 35c, 35d conies in a direct contact with another part of said second portion of said product. Said another part of said second portion of said product will be firmly held in place by said second pair 35c, 35d of removably arranged portions 35 of said solid cellulose foam plank 3. Said second pair further protects said another part of said second portion due to the cushioning properties of said cellulose foam material of the plank 3.

Said whole of said product is protected by said protective packaging insert 1.

Preferably said protective packaging insert comprising said protected product is inserted in an enclosing packaging, preferably comprising cellulose fibres, e.g. a cardboard box.

MATERIALS AND MATERIAL PROPERTIES

Said substrate 2 is preferably made of a material comprising at least one of cardboard, fibreboard, corrugated fibreboard, paper and paperboard.

Said substrate comprises pulp chosen from wood pulps, non-wood pulps, unbleached or bleached chemical pulp, defibrated fiber material, bagasse, straws, hemp, bamboo, spruce CTMP, eucalyptus CTMP, spruce HT CTMP, kraft pulp, sulphite pulp, PGW, GW, DIP, recycled paper and board, broke, RMP, TMP, CMP, CSP NSSC nanopulp, dissolving pulp, and regenerated fibers or mixtures thereof.

Said solid cellulose foam plank 3 comprises: a) from 71-95 wt% cellulose fibres, as calculated on the total weight of solid content of said foam plank 3, b) from 4-24 wt% of a water-soluble thickener, as calculated on the total weight of solid content of said foam plank 3, and c) at least two surfactants. Said cellulose fibres comprised in said solid cellulose foam plank 3 are selected from wood pulp, regenerated cellulose fibres, and plant fibres; preferably selected from softwood pulp, bleached kraft pulp, chemithermomechanical pulp (CTMP) and dissolving pulp or a combination thereof.

A density of said solid cellulose foam plank 3 is in an interval of 10-80 kg/m ³ , preferably 20-50 kg/m ³ and more preferred 20-50 kg/m ³ .

A density of said at least one compressed region 37, 37' is higher than the density of said solid cellulose foam plank 3 provided in step a).

Said density of the at least one compressed region is preferably 10-90% higher than a density of said solid cellulose foam plank provided in step a), more preferred 20-90% and most preferred 40-90%.

Said solid cellulose foam plank comprises at least one densified outer layer. All outer surfaces of the solid cellulose foam plank may comprise a densified outer layer, or the upper surface 31 and the bottom surface 32 of the solid cellulose foam plank 3 may comprise densified outer layers. Preferably, at least the upper surface 31 of the solid cellulose foam plank 3 comprises a densified outer layer.

As will be understood by those skilled in the present field of art, numerous changes and modifications may be made to the above described and other embodiments of the present invention, without departing from the scope of the present invention as defined in the appending claims. For example, said folding line FL5 running through said hole 20 may in some embodiments be excluded.

It is conceivable to first arrange said plank 3 to said top surface 21 of said substrate 2 and thereafter arranging portions of said plank to be removably arranged portions.

Portions of said plank 3 may be fixedly arranged to said plank 3 before arranging other portions of said plank to be removably arranged portions. EXAMPLES

Example 1

A protective packaging insert (similar to the one illustrated in figures 1-3) for a steam iron was constructed from a solid cellulose foam plank having a thickness of 5 cm. The cellulose foam was dry, had a density in the range of from 32 to 35 kg/m ³ and comprised from 83 to 88 wt% cellulose fibres (softwood bleached Kraft pulp), from 10 to 15 wt% thickener (CMC) and about 2 wt% surfactant (mixture of myristic acid and sodium cocoyl sarcosinate).

Four portions of the foam were cut out using a cutting table, thus forming two through- going holes in the plank. The remaining part of the foam plank was shaped corresponding to the base of the steam iron, by pre-cutting and pressing.

The four portions were put back in the plank. Glue was applied to the bottom side of the foam plank and on the top side of the four portions. The foam plank, including the four portions, was then placed on a board (made from virgin pulp fibres, thickness of the board was 1.5 mm). The board had folding lines according to figure 1, so that it could be wrapped around the foam plank. The side sections of the board were folded so that the four portions were attached to them.

The foam plank and board could be stored in the folded state. When the steam iron was to be inserted, the board was unfolded, thus removing the four portions from the foam plank. The steam iron was placed in the shaped foam plank, and the board was folded again so that it was wrapped around the steam iron. The four portions are all in contact with the steam iron after folding. The side sections of the board are connected to each other.

The packaging insert was placed in a box. Drop tests were performed, and the protective packaging insert could protect the steam iron during a fall. The four portions help keeping the steam iron in place in the packaging insert and also provide cushioning properties. If the four portions are not included, the steam iron was not kept in place within the packaging insert.

It should be noted that the above described aspects may be the subject for its own protection, as such in a separate divisional application. Hence, it is foreseen that this aspect of the invention may require a protection by its own, e.g. since it may be applicable per se also in other concepts than that defined by the independent claim in this application.