EP4532812A1

EP4532812A1 - Air-laid blanks and cushioning inserts

Info

Publication number: EP4532812A1
Application number: EP23815369.6A
Authority: EP
Inventors: Maria TÖRNBLOM
Original assignee: Stora Enso Oyj
Current assignee: Stora Enso Oyj
Priority date: 2022-06-03
Filing date: 2023-05-03
Publication date: 2025-04-09
Also published as: US20250340355A1; CN119343491A; WO2023233220A1; SE545796C2; EP4532812A4; MX2024014163A; JP2025518311A; SE2230182A1; CA3258119A1

Abstract

An air-laid blank (10) comprises natural fibers and a polymer binder. The air-laid blank (10) comprises a cushioning portion (14) comprising a plurality of cavities (13) extending into the air-laid blank (10). The air-laid blank (10) also comprises a frame portion (15) lacking any cavities extending into the air-laid blank (10). The frame portion (15) encircles the cushioning portion (14). The air-laid blank (10) is used to produce cushioning inserts (60A, 60B) configured to be inserted into packaging boxes (50) to protect goods or products (70) packaged in the packaging boxed (50).

Description

AIR-LAID BLANKS AND CUSHIONING INSERTS

TECHNICAL FIELD

The present embodiments generally relate to air-laid blanks and methods for producing such air-laid blanks, and in particular air-laid blanks suitable for production of cushioning inserts.

BACKGROUND

With growing awareness for the environment and humanly induced climate change, the use of single-use plastic items and products has come more and more into question. However, despite this concern the use of these items and products has grown vastly with new trends in lifestyles and consumer habits of the last decade. One reason for this is that more and more goods are transported around the globe and these goods need protection against impact or shock. A common way of protecting the goods is to include cushioning elements or products, such as inserts of suitable form into the packaging. These can be made from different materials but are typically made from a foamed polymer, of which expanded polystyrene (EPS) is by far cheapest and most common. EPS is, however, one of the most questioned plastic materials and many brand owners are looking for more sustainable solutions for these packaging applications. Many countries have also begun to take legislative actions against single use plastic items and products, which increases the pressure to find alternative solutions.

More sustainable alternatives to polymer products exist today, such as inserts made by a process known as pulp molding, where a fiber suspension is sucked against a wire mold by vacuum. Another technique for forming such inserts is described in U.S. patent application no. 2010/0190020, European patent no. 1 446 286 and International application no. 2014/142714, which concern hot pressing of porous fiber mats produced by the process called air-laying into 3D structures with matched rigid molds or by membrane molding.

The above exemplified methods, however, produce cushioning inserts that are adapted to protect a particular product or goods. Hence, the design of the wire mold or the matched molds is selected based on the shape and size of the particular product or goods to be protected by the cushioning inserts. There is, however, a need for a generic cushioning insert that could be used to protect products and goods of various shapes and sizes and that can be manufactured using more environmentally friendly materials than polymer foams, such as EPS. SUMMARY

It is an objective to provide an air-laid blank that can be used to produce generic cushioning inserts.

This and other objectives are met by embodiments of the present invention.

The present invention is defined in the independent claims. Further embodiments of the invention are defined in the dependent claims.

An aspect of the invention relates to an air-laid blank comprising natural fibers and a polymer binder. The air-laid blank comprises a cushioning portion comprising a plurality of cavities extending into the air-laid blank and a frame portion lacking any cavities extending into the air-laid blank. The frame portion encircles the cushioning portion.

Another aspect of the invention relates to a method of producing an air-laid blank. The method comprises introducing natural fibers and a polymer binder and/or a mixture of the natural fibers and the polymer binder into at least one inlet of a forming head, transporting the natural fibers and the polymer binder and/or the mixture to an outlet of the forming head and capturing the natural fibers and the polymer binder and/or the mixture as an unbound air-laid web on a collector arranged in connection with the outlet of the forming head. The method also comprises applying gas pulses onto the unbound air-laid web to form a cushioning portion comprising a plurality of cavities extending into the unbound air-laid web. The cushioning portion is encircled by a frame portion of the unbound air-laid web and the frame portion lacks any cavities extending into the unbound air-laid web. The method further comprises heat treating the unbound air-laid web to at least partly melt the polymer binder and form an air-laid blank.

A further aspect of the invention relates to a method of producing an air-laid blank. The method comprises introducing natural fibers into at least one inlet of a forming head, transporting the natural fibers to an outlet of the forming head, and capturing the natural fibers as a web of natural fibers on a collector arranged in connection with the outlet of the forming head. The method also comprises applying gas pulses onto the web of natural fibers on the collector to form a cushioning portion comprising a plurality of cavities extending into the web of natural fibers. The cushioning portion is encircled by a frame portion of the web of natural fibers and the frame portion lacks any cavities extending into the web of natural fibers. The method further comprises applying a polymer binder onto the natural fibers and heat treating the web of natural fibers and the polymer binder to form an air-laid blank. Yet another aspect of the invention relates to a cushioning insert made of an air-laid blank comprising natural fibers and a polymer binder. The cushioning insert comprises a cushioning portion comprising a plurality of cavities extending into the cushioning insert and a frame portion lacking any cavities extending into the cushioning insert. The frame portion encircles the cushioning portion.

The invention also relates to a packaging assembly comprising a packaging box having a bottom and at least one side wall attached to the bottom. The bottom and the at least one side wall define a packaging volume. The packaging assembly also comprises a first cushioning insert according to above arranged on the bottom of the packaging box with the plurality of cavities facing away from the bottom of the packaging box.

The present invention relates to air-laid blanks and cushioning inserts made from such air-laid blanks. The cushioning inserts are highly suitable for cushioning of packaged goods providing excellent shock absorbing and damping properties. The air-laid blanks and the cushioning inserts are designed to comprise a deformable cushioning portion comprising a plurality of cavities and where this cushioning portion adapts to various shapes and sizes of packaged goods. The cushioning portion is encircled by a frame portion lacking cavities and thereby providing structural integrity and strength to the air-laid blanks and cushioning inserts, while at the same time constituting a shock absorbing and damping protection for the packaged goods.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments, together with further objects and advantages thereof, may best be understood by making reference to the following description taken together with the accompanying drawings, in which:

Fig. 1 is a cross-sectional view of a portion of an air-laid blank prior to forming cavities according to an embodiment;

Fig. 2 is a cross-sectional view of a portion of an air-laid blank with a formed cavity according to an embodiment;

Figs. 3A to 3D are illustrative examples of air-laid blanks according to various embodiments;

Fig. 4 is a cross-sectional view of a portion of an unbound air-laid web with a plurality of formed cavities according to an embodiment; Fig. 5 is a cross-sectional view of an air-laid blank produced from the unbound air-laid web in Fig. 4;

Fig. 6 is cross-sectional view of a packaging assembly with a cushioning insert according to an embodiment;

Fig. 7 is cross-sectional view of a packaging assembly with two cushioning inserts according to an embodiment;

Fig. 8 is a flow chart illustrating a method of producing an air-laid blank according to an embodiment;

Fig. 9 is a flow chart illustrating a method of producing an air-laid blank according to another embodiment;

Fig. 10 is a schematic overview of an upstream portion of an apparatus for producing an air-laid blank according to an embodiment;

Fig. 11 is a close-up of a nozzle system of the apparatus shown in Fig. 10;

Fig. 12 is a schematic overview of an upstream portion of an apparatus for producing an air-laid blank according to another embodiment;

Fig. 13 is a close-up of a nozzle system of the apparatus shown in Fig. 12;

Fig. 14 is a schematic overview of an apparatus for producing an air-laid blank according to an embodiment showing the air-laid blank in a longitudinal sectional view; and

Fig. 15 is a schematic overview of an apparatus for producing an air-laid blank according to another embodiment showing the air-laid blank in a longitudinal sectional view.

DETAILED DESCRIPTION

The present embodiments generally relate to air-laid blanks, methods, and apparatuses for producing such air-laid blanks, and in particular air-laid blanks suitable for production of cushioning inserts. Air-laid blanks of the present embodiments are useful for production of cushioning inserts, also referred to as cushioning inlays or cushioning elements in the art, for packaging of products, articles, or goods. These cushioning inserts can then be used as more environmentally friendly replacements to corresponding cushioning inserts made of or from foamed polymers, for instance expanded polystyrene (EPS) or foamed polyurethane (PU). More sustainable alternatives to EPS- or PU-based cushioning inserts have been proposed in the art, such as in U.S. patent application no. 2010/0190020, European patent no. 1 446 286 and International application no. 2014/142714, which concern hot pressing of porous fiber mats produced by the process called air-laying into three dimensional inserts with matched rigid molds or by membrane molding. A significant limitation of these prior art inserts is that they are designed to protect a particular product or goods. Hence, the design of the matched molds is selected based on the shape and size of the particular product or goods to be protected by the cushioning inserts. This is in clear contrast to the present embodiments, which produce generic cushioning inserts that could be used to protect products and goods of various shapes and sizes. Such generic cushioning inserts are in particular desired by companies offering or packing a plurality of different products and goods, such as e-commerce companies.

The cushioning inserts of the present embodiments are formed from an air-laid blank comprising natural fibers and a polymer binder. An air-laid blank, sometimes also referred to as dry-laid blank, air-laid mat, dry-laid mat, air-laid web, or dry-laid web, is formed by a process known as air-laying, in which natural fibers and polymer binders are mixed with air to form a porous fiber mixture deposited onto a support and consolidated or bonded by heating. This air-laid blank is characterized by being porous, having the character of an open cell foam and being produced in a so-called dry forming method, i.e., generally without addition of water. The air-laying process was initially described in U.S. patent no. 3,575,749.

Fig. 1 is a cross-sectional view of a portion of an air-laid blank 10. The air-laying process typically produces air-laid blanks 10 where the vast majority of the natural fibers are oriented with their long axis close to parallel to the major surfaces 11, 12 of the air-laid blank 10 (x-y-plane in Fig. 1) with very little fibers oriented perpendicular to this plane, i.e., along the z-axis in Fig. 1. The fiber structure of the air-laid blank 10, thus, becomes almost stratified or layered in planes perpendicular to the z-axis. The stratified fiber orientation of air-laid blanks 10 as shown in Fig. 1 is good for the strength and stiffness properties of the air-laid blank 10, which thereby enables production of cushioning inserts with desired strength and stiffness properties from the air-laid blank 10. An aspect of the invention relates to an air-laid blank 10, see the cross-sectional views in Figs. 2 and 5 and top views in Figs. 3A to 3C. The air-laid blank 10 comprises natural fibers and a polymer binder. The air-laid blank 10 comprises a cushioning portion 14 and a frame portion 15. The cushioning portion 14 comprises a plurality of cavities 13 extending into the air-laid blank 10, whereas the frame portion 15 lacks any cavities extending into the air-laid blank 10. The frame portion 15 further encircles the cushioning portion 14.

The air-laid blank 10, thus, comprises an internal portion, the cushioning portion 14, and a peripheral portion, the frame portion 15. The cushioning portion 14 comprises a plurality of cavities 13 extending into the air-laid blank 10 in this cushioning portion 14. Fig. 2 illustrates one such cavity 13, whereas Fig. 5 illustrates a plurality of cavities 13 in the cushioning portion 14. The cavities 13 can be viewed as pores or channels, in particular closed channels, extending from one of the major surfaces 11 of the air-laid blank 10 towards the opposite major surface 12 of the air-laid blank 10.

The cushioning portion 14 of the air-laid blank 10 comprises less natural fiber material as compared to the frame portion 15 due to the presence of the plurality of cavities 13. This means that this cushioning portion 14 of the air-laid blank 10 is more deformable as compared to the stiffer frame portion 15 and will thereby, in a cushioning insert 60A, 60B, see Figs. 6 and 7, formed from the air-laid blank 10, deform and adapt to the particular shape and size of products or goods 70 to be packaged in and protected by the cushioning insert 60A, 60B. The frame portion 15 lacking the cavities 13 then provides structural integrity to the air-laid blank 10 and the formed cushioning insert 60A, 60B. Furthermore, the frame portion 15 at the same time constitutes a shock absorbing and damping protection for the packaged products or goods 70.

In an embodiment, the plurality of cavities 13 extend through a portion of a thickness of the air-laid blank 10 from a first major surface 11 of the air-laid blank 10 towards a second, opposite major surface 12 of the air-laid blank 10. In a particular embodiment, the plurality of cavities 13, however, does not extend through the whole thickness of the air-laid blank 10 as shown in Figs. 2 and 5. Hence, the cavities 13 preferably merely extend down to a portion of the thickness from the first major surface 11. In an embodiment, the cavities 13, or at least a majority of the plurality of cavities 13, extend down to a percentage of the thickness of the air-laid blank 10 from the major surface 11 . In a particular embodiment, this percentage is selected within an interval of from 25 % up to 90 %, preferably within an interval of from 35 % up to 90 %, more preferably within an interval of from 50 % up to 90 %, such as within an interval of from 60 % up to 80 %. In an illustrative, but non-limiting, example the cavities 13, or at least a majority thereof, extend down to from two thirds up to three quarters of the thickness of the air-laid blank 10 from the first major surface 11 .

In an embodiment, at least a majority of the plurality of cavities 13 extend through merely a portion of the thickness of the air-laid blank 10 but not through the whole thickness. In such an embodiment, at least some of the cavities 13 may, though, extend through the whole thickness of the air-laid blank 10 and thereby form channels through the air-laid blank 10 from the first major surface 11 to the second major surface 12. It is, though, generally preferred if all or at least a majority of the cavities 13 merely extend through a portion but not the whole thickness. The reason for this is that the cushioning portion 14 will then comprise a bottom 17 comprising the natural fibers and polymer binder that will provide cushioning support and protection for products and goods also from “below” of the lower cushioning insert 60A in Fig. 7 and from “above” of the upper cushioning insert 60B.

The cavities 13 may extend substantially the same distance from the first major surface 11 into the airlaid blank 10, i.e., may have substantially the same depth. The embodiments are, however, not limited thereto. The cavities 13 may instead have different depths into the air-laid blank 10 to thereby present a distribution of different depths. For instance, the depth of the cavities 13 into the air-laid blank 10 could be larger (deeper) in the central portion of the cushioning portion 14 to provide the highest deformability in this central portion, whereas the depth of the cavities 13 decrease towards the frame portion 15 to thereby provide more structural support and stiffness at the more peripheral parts of the air-laid blank 10. In such an embodiment, the depth of the plurality cavities 13 generally decrease when traveling from the center of the cushioning portion 14 towards the frame portion 15. In another embodiment, the depth of the plurality cavities 13 generally increase when traveling from the center of the cushioning portion 14 towards the frame portion 15

The plurality of cavities 13 may, as is further described herein, be achieved by applying gas pulses into the air-laid blank 10, or more correctly into an unbound or unbonded air-laid web 30, see Fig. 14, which is formed into the air-laid blank 10 through heat treatment, and in particular into the first major surface 11, 31 of the air-laid blank 10 or unbound air-laid web 30. The depth of the cavities 13 into the air-laid blank 10 is dependent on the force of the gas pulses. The depth may go from a shallow indentation in the first major surface 11 to a deep pore.

In an embodiment, the force of the gas pulses is controlled to not form any channels through the whole thickness of the air-laid blank 10 but may form cavities 13 in the air-laid blank 10. The force of the gas pulses may also be controlled to achieve different depths of the cavities 13 in different parts of the cushioning portion 14.

Application of gas pulses causes a pile up of natural fiber material 38 onto the frame portion 35 and partly also onto the parts 36 of the cushioning portion 34 between the cavities 33 in the unbound air-laid web 30 as schematically shown in Fig. 4. This piled up natural fiber material 38 will, during the production process, be flattened out causing a de nsificati on of at least a part 19 of the frame portion 15 as shown in Fig. 5. This then means that an average density of the frame portion 15 is higher than an average density of the air-laid blank 10 prior to forming the plurality of cavities 13 in the cushioning portion 14. In other words, an average density of air-laid material in the frame portion 15 is higher than an average density of air-laid material in the cushioning portion 14. Hence, natural fiber material 38 blown away from the cushioning portion 34 of the unbound air-laid web 30 will deposit at the frame portion 35 and will then be pushed into the frame portion 35. This means that the corresponding frame portion 15 of the air-laid blank 10 will thereby become denser, i.e., having a higher density of natural fibers, as compared to other parts of the air-laid blank 10. The higher density further improves the structural and stiffness properties of the frame portion 15.

The plurality of cavities 13 in the cushioning portion 14 could be distributed to form a regular pattern, such as a pre-determined pattern, in the air-laid blank 10, such as a regular grid or matrix as shown in Fig. 3A. It is also possible to form a denser distribution or pattern of the plurality of cavities 13 as compared to a regular grid or matrix, which is shown in Figs. 3B and 3C. In Fig. 3B and 3C, the cavities 13 are distributed in rows or columns that are displaced relative to each other to reduce the distance between adjacent cavities 13 in the cushioning portion 14. Fig. 3C illustrates a distribution of cavities 13 with at least partly overlapping or near overlapping cavities 13. Such a distribution of cavities 13 significantly reduces the amount of air-laid material in the cushioning portion 14 to thereby form pillars or protruding structures 16, see Fig. 5, in the cushioning portion 14. This in turn leads to a very deformable and flexible cushioning insert 60A that well adapts to the shape and size of any products or goods 70 placed on the cushioning portion 64 of the cushioning insert 60A, see Fig. 6.

In an embodiment, a distance between adjacent cavities 13 in the cushioning portion 14 is less than twice the largest side length or diameter of the adjacent cavities 13. In a particular embodiment, the distance is equal to or less than 1.75 times or 1 .5 times the largest side length or diameter of the adjacent cavities 13. In another embodiment, the distance between adjacent cavities 13 in the air-laid blank 10, i.e., in the cushioning portion 14 of the air-laid blank 10, is less than twice the average side length or average diameter of the plurality of cavities 13, or less than twice the largest side length or diameter if having differently sized cavities 13. In a particular embodiment, the distance is equal to or less than 1.75 times or 1 .5 times the average side length or average diameter of the plurality of cavities 13, or equal to or less than 1 .75 times or 1 .5 times the largest side length or diameter if having differently sized cavities 13

The distance between adjacent cavities 13 is defined as the center-to-center distance of the adjacent cavities 13 parallel with the first and second major surfaces 11, 12. Hence, in an embodiment, the distance between the edges of adjacent cavities 13 in the cushioning portion 14 is preferably less than the largest side length or diameter of the adjacent cavities 13. In another embodiment, the distance between adjacent cavities 13 in the cushioning portion 14 is preferably less than the average side length or average diameter of the plurality of cavities 13, or less than the largest side length or diameter if having differently sized cavities.

It may in fact be possible to have even shorter distances between adjacent cavities 13 in the cushioning portion 14. For instance, and as previously mentioned, cavities 13 may in fact at least partly overlap. In such an embodiment, each cavity 13 of at least a portion of the plurality of cavities 13 overlaps with another cavity 13 of at least the portion of the plurality of cavities 13. Such an embodiment is shown in Fig. 3D with overlapping cavities 13. In such a case, a plurality of protruding structures 16 will be formed by the remaining air-laid material, in between the overlapping cavities 13, which is further described herein.

The (center-to-center) distance between adjacent cavities 13 may be substantially the same throughout the cushioning portion 14. In another embodiment, one part of the cushioning portion 14 could have a denser distribution of cavities 13 as compared to another part of the cushioning portion 14. For instance, the distance between adjacent cavities 13 could be shorter at the center of the cushioning portion 14 as compared to the peripheral parts of the cushioning portion 14 close to the frame portion 15. In such an embodiment, the (center-to-center) distance between adjacent cavities 13 generally increases when traveling from the center of the cushioning portion 14 towards the frame portion 15.

The frame portion 15 encircles the cushioning portion 14 as shown in Figs. 3A to 3C and thereby surrounds the cushioning portion 14. This means that the plurality of cavities 13 are framed and encircled by a portion of the air-laid blank 15 that does not comprise cavities. In an embodiment, a width of the frame portion 15 is preferably at least 10 mm, preferably at least 15 mm, and more preferably at least 20 mm, such as at least 25 mm, at least 30 mm, at least 35 mm or at least 40 mm. Width of the frame portion 15 as used herein corresponds to a distance from an edge of the air-laid blank 10 to the cushioning portion 14 as indicated by a W in Fig. 3A.

In an embodiment, the width of the frame portion 15 of the air-laid blank 10 corresponds to a percentage of the width of the air-laid blank 10 and wherein this percentage is selected within an interval of from 2.5 % up to 30 %, preferably within an interval of from 2.5 % up to 25 %, and more preferably within an interval of from 5 % up to 25 %, such as within an interval of from 7.5 % up to 25 %, within an interval of from 10 % up to 25 %, or within an interval of from 10 % up to 20 %.

In an embodiment, the cushioning portion 14 comprises a bottom 17 comprising the natural fibers and the polymer binder and a plurality of protruding structures 16 comprising the natural fibers and the polymer binder. The protruding structures 16 may then be separated from each other and are merely interconnected through the bottom 17 of the cushioning portion 14. In such a case, the cavities 13 are at least partly overlapping. In such an embodiment, the protruding structures 16 form pillars extending from the bottom 17. In another embodiment, the protruding structures 16 may be interconnected with adjacent protruding structures 16 with (thin) walls of natural fibers and the polymer binder. In this latter embodiment, the adjacent cavities 13 are not overlapping but are rather separated by a (thin) part of the air-laid material. It is also possible to combine these embodiments, i.e., having both separate protruding structures 16 and protruding structures 16 interconnected with (thin) walls and thereby a combination of overlapping cavities 13 and non-overlapping cavities 13.

In an embodiment, the cavities 13 may have an average extension, such as average side length or average diameter, parallel with the first and second major surfaces 11, 12 that preferably does not exceed 100 mm, preferably does not exceed 75 mm, and more preferably does not exceed 50 mm, such as being equal to or below 40 mm, equal to or below 30 mm or equal to or below 25 mm.

The cavities 13 may have substantially the same extension, such as side length or diameter, or the airlaid blank 10 could comprise differently sized cavities 13 having different extensions, such as different side lengths or diameters. Furthermore, the overall shape of the cavities 13 could be substantially the same, such as having a cylinder shape as an illustrative, but non-limiting, example. The embodiments are, however, not limited thereto. Hence, the cushioning portion 14 of the air-laid blank 10 could comprise cavities 13 with different overall shapes and forms.

It is generally preferred if the natural fibers in the air-laid blank 10 are short at least as compared to the fibers in glass or mineral wool. Having comparatively short natural fibers promotes formation of a porous air-laid blank 10. In more detail, such short natural fibers are suitable for usage in embodiments of the present invention applying gas pulses onto the air-laid blank 10 to produce cavities 13 in the cushioning portion 14 of the air-laid blank 10.

Length of fibers, such as natural fibers, as referred to herein is length weighted average fiber length. Length weighted average fiber length is calculated as the sum of individual fiber lengths squared divided by the sum of the individual fiber lengths as described in e.g., ISO 16065-1 :2014 Pulps — Determination of fibre length by automated optical analysis — Part 1 : Polarized light method or IS0 16065-2:2014 Pulps — Determination of fibre length by automated optical analysis — Part 2: Unpolarized light method.

In an embodiment, the natural fibers have a length weighted average fiber length of up to 10 mm, preferably of up to 8 mm, more preferably of up to 6 mm, and most preferably up to 5 mm. In a particular embodiment, the natural fibers have a length weighted average fiber length selected within an interval of from 1 mm up to 10 mm, preferably selected within an interval of from 1 mm up to 8 mm, more preferably selected within an interval of from 1 mm up to 6 mm, and most preferably selected within an interval of from 1 mm up to 5 mm.

It is also possible to include a minor portion of longer fibers having a length weighted average fiber length of 10 mm or more.

In an embodiment, the air-laid blank 10 comprises the natural fibers at a concentration of at least 70 % by weight of the air-laid blank 10 and the polymer binder at a concentration selected within an interval of from 2.5 up to 30 % by weight of the air-laid blank 10.

In a preferred embodiment, the air-laid blank 10 comprises the natural fibers in a concentration of at least 72.5 %, more preferably at least 75 %, such as at least 77.5 %, at least 80 %, at least 82.5 %, at least 85 % by weight of the air-laid blank 10. In some applications, even higher concentrations of the natural fibers may be used, such as at least 87.5 %, or at least 90 %, at least 92.5 %, at least 95 % or at least 97.5 % by weight of the air-laid blank 10. In some embodiments, the air-laid blank 10 comprises the polymer binder at a concentration selected within an interval of from 5 up to 30 % by weight of the air-laid blank 10, preferably within an interval of from 10 up to 25 %, such as from 12.5 up to 22.5 % by weight of the air-laid blank 10, or within an interval of from 15 up to 20 % by weight of the air-laid blank 10 or within an interval of from 17.5 up to 22.5 % by weight of the air-laid blank 10.

In other embodiments, the air-laid blank 10 comprises the polymer binder at a concentration selected within an interval of from 2.5 up to 15 % by weight of the air-laid blank 10, preferably within an interval of from 2.5 up to 12.5 % by weight of the air-laid blank 10, more preferably within an interval of from 2.5 up to 10 % by weight of the air-laid blank 10, such as within an interval of from 2.5 up to 7.5 % by weight of the air-laid blank 10.

In an embodiment, the natural fibers are or comprise wood fibers. In an embodiment, the natural fibers are or comprise cellulose and/or lignocellulose fibers. Hence, in an embodiment, the natural fibers contain cellulose, such as in the form of cellulose and/or lignocellulose, i.e., a mixture of cellulose and lignin. The natural fibers may also contain lignin, such as in the form of lignocellulose. The natural fibers may additionally contain hemicellulose. In a particular embodiment, the natural fibers are cellulose and/or lignocellulose pulp fibers produced by chemical, mechanical and/or chemi-mechanical pulping of softwood and/or hardwood. For instance, the cellulose and/or lignocellulose pulp fibers are in a form selected from the group consisting of sulfate pulp, sulfite pulp, thermomechanical pulp (TMP), high temperature thermomechanical pulp (HTMP), mechanical fiber intended for medium density fiberboard (MDF-fiber), chemi-thermomechanical pulp (CTMP), high temperature chemi-thermomechanical pulp (HTCTMP), and a combination thereof.

The natural fibers, such as cellulose and/or lignocellulose pulp fibers, may be bleached or unbleached.

The natural fibers can also be produced by other pulping methods and/or from other cellulosic or lignocellulosic raw materials, such as flax, jute, hemp, kenaf, bagasse, cotton, bamboo, straw, or rice husk. It is also possible to use natural fibers that are a mixture of fibers from different raw materials, such as a mixture of wood and any of the materials mentioned above.

The air-laid blank 10 may also comprise a minor portion of synthetic material or fibers that are mixed with the natural fibers. Such synthetic material or fibers that may be mixed with the natural fibers include, for instance, glass or mineral wool, and/or carbon fibers. Any such synthetic material or fibers may be added at an amount of no more than 10 % (w/w) of the air-laid blank 10, preferably no more than 8 % (w/w), such as no more than 6 % (w/w), or preferably no more than 4 % (w/w) of the air-laid blank 10.

The polymer binder is included in the air-laid blank 10 to bind the air-laid blank 10 together and preserve its form and structure during use, handling, and storage. In an embodiment, the polymer binder may also assist in building up the foam-like structure of the air-laid blank 10. The polymer binder is, in such an embodiment, intermingled with the natural fibers during the air-lying process forming a fiber mixture. The polymer binder may be added in the form of a powder but is more often added in the form of fibers that are intermingled with the natural fibers in the air-laying process. Alternatively, or in addition, the polymer binder may be added as solution, emulsion, or dispersion into and onto the air-laid blank 10 during the air-laying process as is further described below in connection with Fig. 15.

In a particular embodiment, the polymer binder is selected from the group consisting of a polymer powder, polymer fibers and a combination thereof.

The polymer binder could be a natural or synthetic polymer binder, or a mixture of natural polymer binders, a mixture of synthetic polymer binders, or a mixture of natural and synthetic polymer binders, but is preferably a thermoplastic polymer binder.

In an embodiment, the polymer binder is made from i) a material selected from the group consisting of polyethylene (PE), ethylene acrylic acid copolymer (EAA), ethylene-vinyl acetate (EVA), polypropylene (PP), polystyrene (PS), such as styrene-butadiene rubber (SBR) or styrene acrylate copolymer, polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polylactic acid (PLA), polyethylene terephthalate (PET), polycaprolactone (PCL), polyvinyl alcohol (PVA), polyethylene glycol (PEG), poly(2-ethyl-2-oxazoline) (PEOX), polyvinyl ether (PVE), polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyvinyl acetate (PVAc), polyurethane (PU), copolymers thereof and mixtures thereof, and ii) optionally one or more additives.

Hence, in an embodiment, the polymer binder is made of a material selected from the above-mentioned group. In another embodiment, the polymer binder is made of a material selected from the above- mentioned group and one or more additives. In an embodiment, the polymer binder is a thermoplastic polymer binder and preferably selected from the group consisting of a thermoplastic polymer powder, thermoplastic polymer fibers and a combination thereof.

In an embodiment, the polymer binder is or comprises, such as consists of, mono-component and/or bicomponentthermoplastic polymer fibers. Bi-component thermoplastic polymer fibers, also known as bico fibers, comprise a first polymer, copolymer and/or polymer mixture and a second, different polymer, copolymer and/or polymer mixture. Most often the bi-component thermoplastic polymer fiber comprises a core made of the first polymer, copolymer and/or polymer mixture and a sheath made of the second polymer, copolymer and/or polymer mixture, although other combinations of two or even more polymers, copolymers and/or polymer mixtures are possible.

In a particular embodiment, the thermoplastic polymer binder is or comprises, such as consists of, monocomponent thermoplastic polymer fibers made of i) a material selected from the group consisting of PE, EAA, EVA, PP, PS, PBAT, PBS, PLA, PET, PCL, PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, PVAc, PU, copolymers thereof and mixtures thereof, and ii) optionally one or more additives. In another particular embodiment, the thermoplastic polymer binder is or comprises, such as consists of, bi-component thermoplastic polymer fibers having a first material, such as a core made of i) a first material, selected from the group consisting of PE, EAA, EVA, PP, PS, PBAT, PBS, PLA, PET, PCL, PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, PVAc, PU, copolymers thereof and mixtures thereof, and ii) optionally one or more additives, and a second material, such as a sheath made of i) a second material, typically a different material, selected from the group consisting of PE, EAA, EVA, PP, PS, PBAT, PBS, PLA, PET, PCL, PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, PVAc, PU, copolymers thereof and mixtures thereof, and ii) optionally one or more additives. In a further embodiment, the thermoplastic polymer binder is or comprises, such as consists of, a combination or mixture of mono-component thermoplastic polymer fibers made of i) a material selected from the group consisting of PE, EAA, EVA, PP, PS, PBAT, PBS, PLA, PET, PCL, PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, PVAc, PU, copolymers thereof and mixtures thereof, and ii) optionally one or more additives, and bi-component thermoplastic polymer fibers having i) materials, such as of the core and/or sheath, selected from the group consisting of PE, EAA, EVA, PP, PS, PBAT, PBS, PLA, PET, PCL, PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, PVAc, PU, copolymers thereof and mixtures thereof, and ii) optionally one or more additives.

The thermoplastic polymer binder could be made of a single type of thermoplastic polymer fibers, i.e. , made of a same material in the case of mono-component thermoplastic polymer fibers or made of the same materials in the case of bi-component thermoplastic polymer fibers. However, it is also possible to use a thermoplastic polymer binder made of one or multiple, i.e., two or more, different mono-component thermoplastic polymer fibers made of different materials and/or one or multiple different bi-component thermoplastic polymer fibers made of different materials.

An advantage of using bi-component thermoplastic polymer fibers is that they can have a core with a higher melting point that keeps its fiber form during the binding operation, whereas the sheath melts and becomes tacky. The intact core will support the three-dimensional structure of the air-laid blank 10 and, thus, promote porosity while the melted or tackified sheath will attach to the natural fibers and preserve the strength of the air-laid blank 10.

In an embodiment, the polymer binder is a polymer powder, preferably a thermoplastic polymer powder, made of i) a material selected from the group consisting of PE, EAA, EVA, PP, PS, PBAT, PBS, PLA, PET, PCL, PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, PVAc, PU, copolymers thereof and mixtures thereof, and ii) optionally one or more additives.

It is also, as mentioned in the foregoing, possible to use a thermoplastic polymer binder that is a combination of thermoplastic polymer fibers and thermoplastic polymer powder.

The air-laid blank 10 may comprise one or more additives in addition to the natural fibers and the polymer binder. One or more additives could be added to the polymer binder and/or added when producing the polymer binder. Alternatively, or in addition, one or more additives could be added to the natural fibers. Alternatively, or in addition, one or more additives could be added to the natural fibers and the polymer binder, such as during the air-laying process or prior to the air-laying process.

Illustrative, but non-limiting, examples of such additives include electrically conducting or semiconducting fillers, coupling agents, flame retardants, dyes, impact modifiers, etc.

In a particular embodiment, the polymer binder is a natural polymer selected from the group consisting of starch, agar, guar gum, locust bean gum, carrageenan, and cellulose, such as fibrillar, microfibrillar or nanofibrillar cellulose.

In an embodiment, the polymer binder may be in the form of a water-based (aqueous) solution, emulsion, suspension, or dispersion of the polymer binder. Another aspect of the invention relates to a method of producing an air-laid blank 10, see Fig. 8 and Figs. 10-14 showing an embodiment of an apparatus 100 for producing an air-laid blank 10. The method comprises introducing, in step S1 , natural fibers and a polymer binder and/or a mixture of the natural fibers and the polymer binder into at least one inlet 111 of a forming head 110. The method also comprises, transporting, in step S2, the natural fibers and the polymer binder and/or the mixture to an outlet 113 of the forming head 110. The method further comprises capturing, in step S3, the natural fibers and the polymer binder and/or the mixture as an unbound air-laid web 30 on a collector 120 arranged in connection with the outlet 113 of the forming head 110. The method additionally comprises applying, in step S4, gas pulses onto the unbound air-laid web 30 to form a cushioning portion 34 comprising a plurality of cavities 33 extending into the unbound air-laid web 30. The cushioning portion 34 is encircled by a frame portion 35 of the unbound air-laid web 30 and this frame portion 35 lacks any cavities extending into the unbound air-laid web 30. The method further comprises heat treating, in step S5, the unbound air-laid web 30 to at least partly melt the polymer binder and form an air-laid blank 10.

In an embodiment, step S5 comprises heat treating the unbound air-laid web 30 to at least partly melt the polymer binder and form an air-laid blank 10 comprising a cushioning portion 14 comprising a plurality of cavities 13 extending into the air-laid blank 10 and a frame portion 15 lacking any cavities extending into the air-laid blank 10. The frame portion 15 encircles the cushioning potion 14.

The transport or passage of the natural fibers and the polymer binder and/or the mixture in the forming head 110 in step S2 contributes to separation into individual fibers to thereby promote a porous unbound air-laid web 30 on the collector 120.

The apparatus 100 used for producing an air-laid blank 10 comprises a forming head 110, also referred to as forming chamber in the art. The natural fibers and the polymer binder are input or introduced into the forming head 110 as one or more discrete input streams and/or as one or more mixed input streams at one or more inlets 111 . For instance, the forming head 110 may, such as in connection with its upper end 112 or further down in the forming head 110, comprise one stream inlet for the natural fibers and one stream inlet for the polymer binder. In another embodiment, the forming head 110 comprises multiple stream inlets for the natural fibers and one stream inlet for the polymer binder, one stream inlet for the natural fibers and multiple stream inlets for the polymer binder or multiple stream inlets for the natural fibers and multiple stream inlets for the polymer binder. In these illustrative examples, the natural fibers and the polymer binder are mixed and blended during the transport or passage through the forming head 110 ultimately forming an air-laid blank 10 on the collector 120.

Instead of, or as a complement to, having one or more input streams for the natural fibers and/or one or more input streams for the polymer binder, a pre-formed mixture of the natural fibers and the polymer binder may be introduced into the forming head 110 at one or multiple stream inlets 111.

The forming head 110 may include equipment arranged inside the forming head 110 to promote separation and mixing of the natural fibers and the polymer binder, and/or the mixture thereof during the transport or passage through the forming head 110. Such equipment may comprise, for instance, rolls with interlocking spikes, one or more drums, such as slit drums, and/or one or more strainers.

In an embodiment, the collector 120 is an air-permeable collector 120. In such an embodiment, step S3 comprises capturing the natural fibers and the polymer binder and/or the mixture on the air-permeable collector 120, over which a vacuum is applied.

The natural fibers and the polymer binder and/or the mixture thereof is transported up to the forming head 110 by air and enters the forming head 1 10 in the at least one inlet 111 , such as arranged in connection with the upper end 112 of the forming head 110, or further down in the forming head 110. The natural fibers and the polymer binder and/or the mixture thereof is then transported through the forming head 110 to the outlet 113, such as arranged in connection with the lower end 114 of the forming head 110. The natural fibers and the polymer binder and/or the mixture is then captured on the air-permeable collector 120 at least partly by a vacuum, i.e., an air suction or under-pressure, applied over the air- permeable collector 120 that is disposed in connection with the outlet 113 of the forming head 110.

The vacuum applied over the air-permeable collector 120, thus, draws the natural fibers and the polymer binder and/or the mixture thereof down onto the air-permeable collector 120.

The collector 120 is preferably air-permeable to allow application of the vacuum there over and draw the natural fibers and the polymer binder onto the air-permeable collector 120. For instance, the air- permeable collector 120 could comprise a plurality of openings, through holes or channels for allowing air to be sucked or drawn through the air-permeable collector 120. As an illustrative, but non-limiting, example, the air-permeable collector 120 could be a mesh collector 120 comprising a plurality of minute through holes. However, any such openings are preferably small enough to prevent the natural fibers and the polymer binder from passing through the air-permeable collector 120. Hence, the natural fibers and the polymer binder are instead deposited as a mixture onto the air-permeable collector 120 in the form of an unbound air-laid web 30.

The collector 120 could be a plate, disc, mesh, or similar planar collector 120 that is arranged in connection with the outlet 113 of the forming head 110. Once the unbound air-laid web 30 has been formed on the collector 120, the collector 120 may be transferred from the forming head 110 with the unbound air-laid web 30 positioned thereon to be subjected to gas pulses at a nozzle system 130.

In another embodiment, which enables a continuous manufacture of air-laid blanks 10, the collector 120 could be in the form of a belt or wire collector 120, preferably an air-permeable belt or wire collector 120, running between drive rollers 122, 124 as shown in Fig. 14. Such an air-permeable belt or wire collector 120 is also referred to as air-permeable belt or wire conveyor 120. In such an embodiment, step S4 comprises applying the gas pulses onto the unbound air-laid web 30 positioned on the belt collector 120 downstream of the forming head 110.

Downstream relates to the movement direction of the belt collector 120 from the drive roller 122 towards the drive roller 124. Hence, the gas pulses are applied onto the unbound air-laid web 30 in step S4 once the unbound air-laid web 30 has exited the forming head 110.

In an embodiment, the gas pulses are applied in step S4 by selectively applying gas pulses using multiple fixed gas nozzles 132, such as in one or more rows, see Figs. 11 and 13, arranged downstream of the forming head 110. Alternatively, or in addition, the gas pulses could be selectively applied in step S4 using at least one movable gas nozzle 132 arranged downstream of the forming head 110 and selectively movable relative to the unbound air-laid web 30 positioned on the belt collector 120.

Figs. 11 and 13 schematically illustrate a nozzle system 130 comprising multiple gas nozzles 132 distributed along the width of the unbound air-laid web 30 (Fig. 11), or at least along a portion of the width of the unbound air-laid web 30 (Fig. 13). Gas pulses could then be selectively applied in step S4 using these gas nozzles 132 to form cavities 33 in the unbound air-laid web 30. Selectively applied as used herein implies, in an embodiment, that the gas nozzles 132 are controlled, such as by a controller 140, see Figs. 10 and 12, to apply the gas pulses at selected time instances or periods of time as the unbound air-laid web 30 is moved past the nozzle system 130 on the belt collector 120. In such an embodiment, the gas nozzles 132 may extend over a majority of the width of the unbound air-laid web 30 as shown in Fig. 10 but not up to the ends of the unbound air-laid web 30 to prevent formation of cavities 33 in the peripheral parts of the unbound air-laid web 30, which form part of the frame portion 35. In another embodiment, the gas nozzles 132 are provided as multiple groups as shown in Figs. 12 and 13 with a gap between adjacent groups of gas nozzles 132. Such an approach enables generation of cushioning portions 34 side-by-side with intermediate frame portion 35 in the unbound air-laid web 30. All the gas nozzles 132 could then be operated by the controller 140 to apply gas pulses at the same time.

In another embodiment, the controller 140 could selectively activate the gas nozzles 132 to apply gas pulses so that not all gas nozzles 132 of the nozzle system 130 apply gas pulses at the same time. This allows generation of more or less regular patterns, such as matrices or grids, of cavities 33 in the unbound air-laid web 30. This embodiment also enables control of the widths of the frame portion 35 in the unbound air-laid web 30.

In Figs. 10 to 13, a single row of gas nozzles 132 are arranged over the belt collector 120. The embodiments are, however, not limited thereto. In clear contrast, multiple such rows of gas nozzles 132 could be arranged relative to the collector 120. In such a case, the gas nozzles 132 could be arranged in a matrix or grid. It is also possible to have multiple rows of gas nozzles 132 displaced relative to each other to form a pattern of cavities 33 as shown in Figs. 3B or 3C.

Instead of, or as a complement to, having a nozzle system 130 with fixed gas nozzles 132, one or more movable gas nozzles 132 could be arranged downstream of the forming head 110. In such a case, the controller 140 could control the at least one movable gas nozzle 132 to move relative to the unbound airlaid web 30 and selectively apply gas pulses onto the unbound air-laid web 30. In such a case, the at least one movable gas nozzle 132 is preferably at least movable along the width of the unbound air-laid web 30.

The heat treatment applied in step S5 performs a bonding operation, in which the unbound air-laid web 30 is introduced into a bonding oven 150, see Fig. 14, where heat, such as in the form of heated air, is circulated through the unbound air-laid web 30 to melt or partially melt the polymer binder. The polymer binder thereby becomes tacky and adheres to the natural fibers and, thus, holds the fiber material together and thereby resulting in an air-laid blank 10.

The heat treatment of step S5 causes at least a partial melting of the polymer binder to thereby become tacky and adhere to the natural fibers in the unbound air-laid web 30. As a consequence, the natural fibers and polymer binder hold together and form an air-laid blank 10. This heat treatment in step S5 preserves the cavities 33 formed in step S4 by applying gas pulses. Hence, the air-laid blank 10 comprises a cushioning portion 14 comprising a plurality of cavities 13 encircled or surrounded by the frame portion 15.

The bonding operation may also comprise, and/or be accompanied by, a densification to create a larger number of binding points in the fiber structure and, thus, a stronger and denser air-laid blank 10. Such a densification operation could be applied either before the air-laid blank 10 has been allowed to cool after the bonding oven 150 or upon renewed heating, such as in a heated calender. It is also possible to perform the densification operation in the bonding oven 150, e.g., as a combined heating and densification operation. In this latter case, step S5 comprises heat treating the unbound air-laid web 30 to at least partly melt the polymer binder and simultaneously applying pressure onto the unbound air-laid web 30 to form the air-laid blank 10. The densification can include various types of operations including, but not limited to, calendering and/or pressing operations. Fig. 5 schematically illustrates a cross- sectional view of the air-laid blank 10 following heat treatment and densification of the unbound air-laid web 30 shown in Fig. 4. As is shown in Fig. 5, the plurality of cavities 13 are preserved in the air-laid blank 10 after the heat treatment and the densification operation.

In the above-described embodiment, the air-laid blank 10 is produced by introducing both the natural fibers and the polymer binder into the forming head 110. Fig. 9 is a flow chart illustrating another embodiment of a method of producing an air-laid blank 10, see also Fig. 15. The method comprises introducing, in step S10, natural fibers into at least one inlet 111 of a forming head 110. The method also comprises transporting, in step S11, the natural fibers to an outlet 113 of the forming head 110 and capturing, in step S12, the natural fibers as a web 40 of natural fibers on a collector 120 arranged in connection with the outlet 113 of the forming head 110. The method further comprises applying, in step S13, gas pulses onto the web 40 of natural fibers on the collector 120 to form a cushioning portion 44 comprising a plurality of cavities 43 extending into the web 40 of natural fibers. The cushioning portion 44 is encircled by a frame portion 45 of the web 40 of natural fibers and the frame portion 45 lacks any cavities 43 extending into the web 40 of natural fibers. In this embodiment, the method also comprises applying a polymer binder onto the natural fibers in step S14. The method additionally comprises heat treating, in step S15, the web 40 of natural fibers and the polymer binder to form an air-laid blank 10.

In an embodiment, step S15 comprises heat treating S15 the web 40 of natural fibers and the polymer binder to form an air-laid blank 10 comprising a cushioning portion 14 comprising a plurality of cavities 13 extending into the air-laid blank 10 and a frame portion 15 lacking any cavities extending into the airlaid blank 10. The frame portion 15 encircles the cushioning portion 14.

This embodiment of the method differs from the one as discussed above in connection with Fig. 8 in that no polymer binder is introduced into the forming head 110 in step S10. In clear contrast, one or multiple streams of natural fibers and/or mixtures thereof are introduced in step S10 through one or multiple inlets 111 in the forming head 110. The natural fibers are transported or passed through the forming head 110 in step S11 and then captured as a web 40 of natural fibers on the collector in step S12. Gas pulses are then applied to this web 40 of natural fibers in step S13 in a similar way to step S4 in Fig. 8 to form cavities 43 in the web 40 of natural fibers. In this embodiment, the polymer binder is then applied to the web 40 of natural fibers in step S14 prior to exposing the web 40 of natural fibers and the polymer binder to heat in the downstream bonding oven 150 in step S15.

Hence, in this embodiment, the apparatus 100 comprises a device 160 arranged downstream of the nozzle system 130 but upstream of the bonding oven 150 to apply the polymer binder. This device 160 may apply the polymer binder as, for instance, a solution, emulsion, suspension, or dispersion into and onto the web 40 of natural fibers in step S14. For instance, the polymer binder may be sprayed onto the web 40 of natural fibers in step S14. In an illustrative embodiment, the polymer binder is in the form of a water-based (aqueous) solution, emulsion, suspension, or dispersion of at least one polymer binder in the form of one or more synthetic polymers and/or one or more natural polymers. In such a case, the polymer binder could be selected among the previously described polymer binder materials.

The following step S15 in Fig. 9 is performed in the same way as step S5 in Fig. 8. However, depending on the material of the polymer binder applied in step S14, the heat treatment applied in step S15 does not necessarily at least partly melt the polymer binder in the bonding oven 150 but may, if the polymer binder is in the form of a water-based solution, emulsion, suspension, or dispersion dry off the water to form the air-laid blank 10. Such a drying operation also applies to using solvents other than water for the polymer binder.

The various embodiments of steps S1 to S5 described above can be applied mutatis mutandis to the method as shown in Fig. 9 except for not introducing any polymer binder in step S10.

The two described embodiments shown in Figs. 8 and 9 may also be combined. Hence, polymer binder may be introduced into the forming head as described above in connection with step S1 in Fig. 8 and additional polymer binder may then also be applied to the unbound air-laid web 30 as described in step S14 in Fig. 9 to, for instance, strengthen the surface of the resulting air-laid blank 10.

The methods described above and shown in the flow chart of Figs. 8 and 9 are suitable for producing airlaid blanks 10 according to the present invention, such as shown in Figs. 2, 3 and 5. Hence, the air-laid blank 10 is obtainable or obtained by the methods described above and shown in the flow chart of Fig. 8 or 9.

The methods disclosed in Figs. 8 and 9 may also include an additional step S6 or S16 comprising cutting the air-laid blank 10 into cushioning inserts 60A, 60B. In a general embodiment, the air-laid blank 10 comprises multiple cushioning portions 14 encircled by respective frame portions 15. In such a case, the air-laid blank 10 is preferably cut in step S6 or S16 to form multiple cushioning inserts 60A, 60B.

The cutting operation in step S6 or S16 could be performed using any suitable cutter or cutting means. Illustrative, but non-limiting examples, of such cutting means include a saw, a punch, a knife, etc.

The present invention also relates to a cushioning insert 60A, 60B made of an air-laid blank 10 comprising natural fibers and a polymer binder, see Figs. 6 and 7. The cushioning insert 60A, 60B comprises a cushioning portion 64 and a frame portion 65. The cushioning portion 64 comprising a plurality of cavities 63 extending into the cushioning insert 60A, 60B. The frame portion 65 lacks any cavities extending into the cushioning insert 60A, 60B. The frame portion 65 encircles the cushioning portion 64.

The cushioning insert 60A, 60B is produced from the air-laid blank 10 of the invention, such as by cutting the air-laid blank 10 into multiple cushioning inserts 60A, 60B in step S6 or S16 in Figs. 8 and 9. The cushioning insert 60A, 60B is then cut to have an overall size and shape to fit into a packaging box 50 as shown in Figs. 6 and 7.

The various embodiments described in the foregoing regarding the air-laid blank 10 also apply to the cushioning insert 60A, 60B that is produced from the air-laid blank 10.

In an embodiment, the plurality of cavities 63 extend through a portion of a thickness of the cushioning insert 60A, 60B from a first major surface 61 of the cushioning insert 60A, 60B towards a second, opposite major surface 62 of the cushioning insert 60A, 60B but not through the whole thickness of the cushioning insert 60A, 60B. In an embodiment, the cavities 63, or at least a majority of the plurality of cavities 63, extend down to a percentage of the thickness of the cushioning insert 60A, 60B from the major surface 61. In a particular embodiment, this percentage is selected within an interval of from 25 % up to 90 %, preferably within an interval of from 35 % up to 90 %, more preferably within an interval of from 50 % up to 90 %, such as within an interval of from 60 % up to 80 %. In an illustrative, but non-limiting, example the cavities 63, or at least a majority thereof, extend down to from two thirds up to three quarters of the thickness of the cushioning insert 60A, 60B from the first major surface 61 .

In an embodiment, a distance between adjacent cavities 63 in the cushioning portion 64 is less than twice the largest side length or diameter of the adjacent cavities 63. In a particular embodiment, the distance is equal to or less than 1.75 times or 1 .5 times the largest side length or diameter of the adjacent cavities 63.

In another embodiment, the distance between adjacent cavities 63 in the cushioning portion 64 is less than twice the average side length or average diameter of the plurality of cavities 63, or less than twice the largest side length or diameter if having differently sized cavities 63. In a particular embodiment, the distance is equal to or less than 1 .75 times or 1 .5 times the average side length or average diameter of the plurality of cavities 63, or equal to or less than 1.75 times or 1.5 times the largest side length or diameter if having differently sized cavities 63.

As discussed in the foregoing, the distance is defined as the center-to-center distance of the cavities 63 parallel with first and second major surfaces 61 , 62 of the cushioning insert 60A, 60B.

It may in fact be possible to have even shorter distances between adjacent cavities 63 in the cushioning portion 64. For instance, cavities 63 may in fact at least partly overlap. In such an embodiment, each cavity 63 of at least a portion of the plurality of cavities 63 overlaps with another cavity 63 of at least the portion of the plurality of cavities 63.

In an embodiment, a width of the frame portion 65 is preferably at least 10 mm, preferably at least 15 mm, and more preferably at least 20 mm., such as at least 25 mm, at least 30 mm, at least 35 mm or at least 40 mm Width of the frame portion 65 as used herein corresponds to a distance from an edge of the cushioning insert 60A, 60B to the cushioning portion 64.

In an embodiment, the width of the frame portion 65 of a cushioning insert 60A, 60B corresponds to a percentage of the width of the cushioning insert 60A, 60B and wherein this percentage is selected within an interval of from 2.5 % up to 30 %, preferably within an interval of from 2.5 % up to 25 %, and more preferably within an interval of from 5 % up to 25 %, such as within an interval of from 7.5 % up to 25 %, within an interval of from 10 % up to 25 %, or within an interval of from 10 % up to 20 %.

In an embodiment, the cushioning portion 64 comprises a bottom 67 and a plurality of protruding structures 66 extending from the bottom 67.

The cushioning portion 14 of the air-laid blank W and thereby the cushioning portion 64 of the cushioning insert 60A, 60B may have various shapes in terms of the distribution of the cavities 13, 63 in the cushioning portion 14, 64. For instance, the cushioning portion 14, 64 may be quadratic, rectangular, circular, elliptical, or indeed any other shape. The shape and/or size of the cushioning portion 14, 64 may, in an embodiment, be dependent at least partly on the shape and/or size of the products or goods 70 to be packaged in a packaging box 50 and protected by the cushioning insert 60A, 60B. However, an advantage of the invention is that the cushioning insert 60A, 60B can be used to protect various products and goods 70 from shock and impact regardless of whether the cavities 13, 63 in the cushioning portion 14, 64 collectively form, for instance, a quadratic shape or a circular shape.

The outer dimensions and shape of the cushioning insert 60A, 60B are preferably selected based on the dimensions and shape of the packaging box 50, into which the cushioning insert 60A, 60B is to be inserted as shown in Figs. 6 and 7.

An aspect of the invention therefore relates to a packaging assembly comprising a packaging box 50 and a first cushioning insert 60A. The packaging box 50 has a bottom 53 and at least one side wall 51 , 52 attached to the bottom 53. The bottom 53 and the at least one side wall define a packaging volume 54. The first cushioning insert 60A according to the invention is arranged on the bottom 53 of the packaging box 50 with the plurality of cavities 63 facing away from the bottom 53 of the packaging box 50 as shown in Fig. 6.

In an embodiment, the packaging assembly also comprises a second cushioning insert 60B according to the invention, see Fig. 7. In such an embodiment, the second cushioning insert 60B is arranged in the packaging volume 54 with the plurality of cavities 63 facing the first cushioning insert 60A.

Any goods or products 70 to be packed in the packaging assembly are positioned in between the first and second cushioning inserts 60A, 60B as indicated in Fig. 7. The cavities 63 of the two cushioning inserts 60A, 60B then face each other and the goods or products 70 placed therebetween. The cavities 63 present in the cushioning portions 64 of the two cushioning inserts 60A, 60B make these parts of the cushioning inserts 60A, 60B deformable to accompany goods or products 70 and adapt to the particular shape and/or size of the goods or products 70. The surrounding frame portions 65 lack cavities and are thereby stiffer and have higher structural integrity as compared to the cushioning portions 64. This means that the frame portions 65 thereby provide support to the cushioning inserts 60A, 60B but also protection against shock and impact from outside of the at least one side wall 51 , 52 of the packaging box 50.

The packaging assembly could be used to pack a single product or goods 70 or multiple products or goods 70 in the packaging box 50.

The packaging box 50, also referred to as container herein, could comprise a single side wall attached to the bottom 53, for instance, if the packaging box 50 is in the form of cylinder with a circular or elliptical bottom 53. The side wall is then a curved side wall encircling a circular or elliptical bottom 53. In such an embodiment, the packaging box 50 is a cylindrical packaging box 50. In other embodiments, the packaging box 50 could be in form of a cube or rectangular cuboid. In such embodiments, the packaging box 50 comprises four side walls 51 , 52 attached to the bottom 53.

The packaging box 50 can be made of various materials including, but not limited, to paper-based material, including, but not limited to, paperboard material, such as a cardboard material, cartonboard material or corrugated board material, also referred to as containerboard material. In a particular embodiment, the packaging box 50 is a cardboard box or a corrugated board box. Another material for the packaging box 50 could be wood.

The embodiments described above are to be understood as a few illustrative examples of the present invention. It will be understood by those skilled in the art that various modifications, combinations, and changes may be made to the embodiments without departing from the scope of the present invention. In particular, different part solutions in the different embodiments can be combined in other configurations, where technically possible.

Claims

1 . An air-laid blank (10) comprising: natural fibers; and a polymer binder, wherein the air-laid blank (10) comprises: a cushioning portion (14) comprising a plurality of cavities (13) extending into the air-laid blank (10); and a frame portion (15) lacking any cavities extending into the air-laid blank (10), wherein the frame portion (15) encircles the cushioning portion (14).

2. The air-laid blank according to claim 1 , wherein the plurality of cavities (13) extends through a portion of a thickness of the air-laid blank (10) from a first major surface (11) of the air-laid blank (10) towards a second, opposite major surface (12) of the air-laid blank (10) but not through the whole thickness of the air-laid blank (10).

3. The air-laid blank according to claim 1 or 2, wherein a distance between adjacent cavities (13) in the cushioning portion (14) is less than twice a largest side length or diameter of the adjacent cavities (13).

4. The air-laid blank according to claim 1 or 2, wherein a distance between adjacent cavities (13) in the cushioning portion (14) is less than twice an average side length or average diameter of the plurality of cavities (13).

5. The air-laid blank according to any one of claims 1 to 4, wherein each cavity (13) of at least a portion of the plurality of cavities (13) overlaps with another cavity (13) of at least the portion of the plurality of cavities (13).

6. The air-laid blank according to any one of claims 1 to 5, wherein the cushioning portion (14) further comprises: a bottom (17) comprising the natural fibers and the polymer binder; and a plurality of protruding structures (16) comprising the natural fibers and the polymer binder and extending from the bottom (17).

7. The air-laid blank according to any one of claims 1 to 6, wherein an average density of air-laid material in the frame portion (15) is higher than an average density of air-laid material in the cushioning portion (14).

8. The air-laid blank according to any one of claims 1 to 7, wherein the natural fibers have a length weighted average fiber length of up to 10 mm, preferably up to 8 mm, more preferably of up to 6 mm, and most preferably up to 5 mm, such as selected within an interval of from 1 mm up to 10 mm, preferably within an interval of from 1 mm up to 8 mm, more preferably within an interval of from 1 mm up to 6 mm, and most preferably within an interval of from 1 mm up to 5 mm.

9. The air-laid blank according to any one of claims 1 to 8, wherein the air-laid blank (10) comprises: the natural fibers at a concentration of at least 70 % by weight of the air-laid blank (10); and the polymer binder at a concentration selected within an interval of from 2.5 up to 30 % by weight of the air-laid blank (10).

10. The air-laid blank according to any one of claims 1 to 9, wherein the natural fibers comprise wood fibers, preferably cellulose and/or lignocellulose fibers, and more preferably cellulose and/or lignocellulose pulp fibers produced by chemical, mechanical and/or chemi-mechanical pulping of softwood and/or hardwood.

11. The air-laid blank according to claim 10, wherein the natural fibers are cellulose and/or lignocellulose pulp fibers in a form selected from the group consisting of sulfate pulp, sulfite pulp, thermomechanical pulp (TMP), high temperature thermomechanical pulp (HTMP), mechanical fiber intended for medium density fiberboard (MDF-fiber), chemi-thermomechanical pulp (CTMP), high temperature chemi-thermomechanical pulp (HTCTMP), and a combination thereof.

12. The air-laid blank according to any one of claims 1 to 11 , wherein the polymer binder is selected from the group consisting of a polymer powder, polymer fibers, and a combination thereof, preferably selected from the group consisting of a thermoplastic polymer powder, thermoplastic polymer fibers and a combination thereof.

13. The air-laid blank according to claim 12, wherein the thermoplastic polymer fibers are selected from the group consisting of mono-component thermoplastic polymer fibers, bi-component thermoplastic polymer fibers and a mixture thereof, preferably bi-component thermoplastic polymer fibers.

14. The air-laid blank according to any one of claims 1 to 13, wherein the polymer binder is made from i) a material selected from the group consisting of polyethylene (PE), ethylene acrylic acid copolymer (EAA), ethylene-vinyl acetate (EVA), polypropylene (PP), polystyrene (PS), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polylactic acid (PLA), polyethylene terephthalate (PET), polycaprolactone (PCL), polyvinyl alcohol (PVA), polyethylene glycol (PEG), poly(2-ethyl-2- oxazoline) (PEOX), polyvinyl ether (PVE), polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyvinyl acetate (PVAc), polyurethane (PU), copolymers thereof and mixtures thereof, and ii) optionally one or more additives.

15. A method of producing an air-laid blank (10), the method comprising: introducing (S1) natural fibers and a polymer binder and/or a mixture of the natural fibers and the polymer binder into at least one inlet (111 ) of a forming head (110); transporting (S2) the natural fibers and the polymer binder and/or the mixture to an outlet (113) of the forming head (110); capturing (S3) the natural fibers and the polymer binder and/or the mixture as an unbound air-laid web (30) on a collector (120) arranged in connection with the outlet (113) of the forming head (110); applying (S4) gas pulses onto the unbound air-laid web (30) to form a cushioning portion (34) comprising a plurality of cavities (33) extending into the unbound air-laid web (30), wherein the cushioning portion (34) is encircled by a frame portion (35) of the unbound air-laid web (30) and the frame portion (35) lacks any cavities extending into the unbound air-laid web (30); and heat treating (S5) the unbound air-laid web (30) to at least partly melt the polymer binder and form an air-laid blank (10).

16. The method according to claim 15, wherein heat treating (S5) comprises heat treating (S5) the unbound air-laid web (30) to at least partly melt the polymer binder and form an air-laid blank (10) comprising a cushioning portion (14) comprising a plurality of cavities (13) extending into the air-laid blank (10) and a frame portion (15) lacking any cavities extending into the air-laid blank (10), wherein the frame portion (15) encircles the cushioning portion (14).

17. A method of producing an air-laid blank (10), the method comprising: introducing (S10) natural fibers into at least one inlet (111 ) of a forming head (110); transporting (S11) the natural fibers to an outlet (113) of the forming head (110); capturing (S12) the natural fibers as a web (40) of natural fibers on a collector (120) arranged in connection with the outlet (113) of the forming head (110); applying (S13) gas pulses onto the web (40) of natural fibers on the collector (120) to form a cushioning portion (44) comprising a plurality of cavities (43) extending into the web (40) of natural fibers, wherein the cushioning portion (44) is encircled by a frame portion (45) of the web (40) of natural fibers and the frame portion (45) lacks any cavities (43) extending into the web (40) of natural fibers; applying (S14) a polymer binder onto the natural fibers; and heat treating (S15) the web (40) of natural fibers and the polymer binder to form an air-laid blank (10).

18. The method according to claim 17, wherein heat treating (S15) comprises heat treating (S15) the web (40) of natural fibers and the polymer binder to form an air-laid blank (10) comprising a cushioning portion (14) comprising a plurality of cavities (13) extending into the air-laid blank (10) and a frame portion (15) lacking any cavities extending into the air-laid blank (10), wherein the frame portion (15) encircles the cushioning portion (14).

19. The method according to any one of claims 15 to 18, wherein the method is for producing an airlaid blank (10) according to any one of claims 1 to 14.

20. A cushioning insert (60A, 60B) made of an air-laid blank (10) comprising natural fibers and a polymer binder, wherein the cushioning insert (60A, 60B) comprises: a cushioning portion (64) comprising a plurality of cavities (63) extending into the cushioning insert (60A, 60B); and a frame portion (65) lacking any cavities extending into the cushioning insert (60A, 60B), wherein the frame portion (65) encircles the cushioning portion (64).

21 . The cushioning insert according to claim 20, wherein the plurality of cavities (63) extend through a portion of a thickness of the cushioning insert (60A, 60B) from a first major surface (61) of the cushioning insert (60A, 60B) towards a second, opposite major surface (62) of the cushioning insert (60A, 60B) but not through the whole thickness of the cushioning insert (60A, 60B).

22. The cushioning insert according to claim 20 or 21, wherein a distance between adjacent cavities (63) in the cushioning portion (64) is less than twice a largest side length or diameter of the adjacent cavities (63).

23. The cushioning insert according to claim 20 or 21, wherein a distance between adjacent cavities (63) in the cushioning portion (64) is less than twice an average side length or average diameter of the plurality of cavities (63).

24. The cushioning insert according to any one of claims 20 to 23, wherein each cavity (63) of at least a portion of the plurality of cavities (63) overlaps with another cavity (63) of at least the portion of the plurality of cavities (63).

25. The cushioning insert according to any one of claims 20 to 24, wherein the cushioning portion (64) further comprises: a bottom (67); and a plurality of protruding structures (66) extending from the bottom (67).

26. The cushioning insert according to any one of claims 20 to 25 made of an air-laid blank (10) according to any one of claims 1 to 14.

27. A packaging assembly comprising: a packaging box (50) having a bottom (53) and at least one side wall (51 , 52) attached to the bottom (53), wherein the bottom (53) and the at least one side wall define a packaging volume (54); and a first cushioning insert (60A) according to any one of claims 20 to 26 arranged on the bottom (53) of the packaging box (50) with the plurality of cavities (63) facing away from the bottom (53) of the packaging box (50).

28. The packaging assembly according to claim 27, further comprising a second cushioning insert (60B) according to any one of claims 20 to 26 arranged in the packaging volume (54) with the plurality of cavities (63) facing the first cushioning insert (60A).