Airlaid blank and cushioning insert

Abstract

The air laid blank (10) comprises natural fibers and a polymeric binder. The airlaid blank (10) comprises a cushioning portion (14) comprising a plurality of cavities (13) extending into the airlaid blank (10). The airlaid blank (10) also includes a frame portion (15) lacking any cavity extending into the airlaid blank (10). The frame portion (15) surrounds the buffer portion (14). The airlaid blank (10) is used to produce a cushioning insert (60A, 60B) configured to be inserted into a packaging box (50) to protect goods or products (70) packaged in the packaging box (50).

Description

Technical Field

[0001] Embodiments of the present invention are generally directed to airlaid blanks, and methods for producing such airlaid blanks and in particular airlaid blanks suitable for producing cushioning inserts. Background Art

[0002] As awareness of the environment and human-induced climate change continues to grow, the use of single-use plastic items and products has become increasingly questioned. However, despite this concern, the use of these items and products has grown significantly with new trends in lifestyle and consumer habits over the past decade. One of the reasons for this is that more and more goods are shipped around the world, and these goods need to be protected from shock or vibration. A common way to protect the goods is to include cushioning elements or products, such as inserts of suitable form into the packaging. These can be made of different materials, but are typically made of foamed polymers, of which expanded polystyrene (EPS) is by far the cheapest and most common. However, EPS is 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 has increased the pressure to find alternative solutions.

[0003] There are more sustainable alternatives to polymer products today, such as inserts made by a process called pulp molding, in which a fiber suspension is drawn onto a wire mesh 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, all of which involve hot pressing a porous fiber mat produced by a process called air-laying into a 3D structure using a matching rigid mold or by film molding.

[0004] However, the above exemplary methods produce cushioning inserts that are suitable for protecting specific products or goods. Therefore, the design of the wire mesh mold or matching mold is selected based on the shape and size of the specific product or goods to be protected by the cushioning insert. However, there is a need for a universal cushioning insert that can be used to protect products and goods of various shapes and sizes and can be manufactured using materials that are more environmentally friendly than polymer foams (such as EPS). Summary of the invention

[0005] One object is to provide airlaid blanks that can be used to produce universal cushioning inserts.

[0006] This and other objects are met by embodiments of the present invention.

[0007] The invention is defined in the independent claim. Further embodiments of the invention are defined in the dependent claims.

[0008] One aspect of the present invention relates to an airlaid blank comprising natural fibers and a polymer binder. The airlaid blank comprises a cushioning portion comprising a plurality of cavities extending into the airlaid blank and a frame portion lacking any cavities extending into the airlaid blank. The frame portion surrounds the cushioning portion.

[0009] Another aspect of the present invention relates to a method for producing an air-laid blank. The method includes introducing natural fibers and a polymer binder and / or a mixture of natural fibers and a polymer binder into at least one inlet of a forming head, conveying the natural fibers and the polymer binder and / or the mixture to the outlet of the forming head, and capturing the natural fibers and the polymer binder and / or the mixture as an unbonded air-laid web on a collector, which is arranged to be connected to the outlet of the forming head. The method also includes applying a gas pulse to the unbonded air-laid web to form a buffer portion comprising a plurality of cavities extending into the unbonded air-laid web. The buffer portion is surrounded by a frame portion of the unbonded air-laid web, and the frame portion lacks any cavity extending into the unbonded air-laid web. The method further includes heat treating the unbonded air-laid web to at least partially melt the polymer binder and form an air-laid blank.

[0010] Another aspect of the present invention relates to a method for producing an airlaid blank. The method includes introducing natural fibers into at least one inlet of a forming head, conveying the natural fibers to an outlet of the forming head, and capturing the natural fibers as a web of natural fibers on a collector, which is arranged to be connected to the outlet of the forming head. The method also includes applying a gas pulse to the web of natural fibers on the collector to form a buffer portion containing a plurality of cavities extending into the web of natural fibers. The buffer portion is surrounded 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 includes applying a polymer binder to the natural fibers, and heat treating the web of natural fibers and the polymer binder to form the airlaid blank.

[0011] Yet another aspect of the present invention relates to a cushioning insert made from an airlaid 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 surrounds the cushioning portion.

[0012] The present invention also relates to a packaging assembly, which comprises 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 buffer insert according to the above, arranged on the bottom of the packaging box, wherein the plurality of cavities face away from the bottom of the packaging box.

[0013] The present invention relates to airlaid blanks and cushioning inserts made from such airlaid blanks. The cushioning inserts are highly suitable for cushioning packaged goods, thereby providing excellent shock absorption and damping characteristics. The airlaid blanks and cushioning inserts are designed to include a deformable cushioning portion, which includes a plurality of cavities and wherein the cushioning portion adapts to various shapes and sizes of packaged goods. The cushioning portion is surrounded by a frame portion lacking cavities, thereby providing structural integrity and strength to the airlaid blanks and cushioning inserts, and at the same time providing shock absorption and damping protection for the packaged goods. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The embodiments and further objects and advantages thereof may best be understood by referring to the following description taken in conjunction with the accompanying drawings, in which:

[0015] Figure 1 is a cross-sectional view of a portion of an airlaid blank before forming cavities according to one embodiment;

[0016] Figure 2 is a cross-sectional view of a portion of an airlaid blank having a forming cavity according to one embodiment;

[0017] Figures 3A to 3D are illustrative examples of airlaid blanks according to various embodiments;

[0018] Figure 4 is a cross-sectional view of a portion of an unbonded airlaid web having a plurality of forming cavities according to one embodiment;

[0019] Figure 5 Is Figure 4 A cross-sectional view of an airlaid blank produced without incorporating an airlaid web;

[0020] Figure 6 is a cross-sectional view of a packaging assembly having a cushioning insert according to one embodiment;

[0021] Figure 7 is a cross-sectional view of a packaging assembly having two cushioning inserts according to one embodiment;

[0022] Figure 8 is a flow chart illustrating a method of producing an airlaid blank according to one embodiment;

[0023] Fig. 9is a flow chart illustrating a method of producing an airlaid blank according to another embodiment;

[0024] Fig.10 is a schematic overview of an upstream portion of an apparatus for producing airlaid blanks according to one embodiment;

[0025] Fig.11 yes Fig.10 A close-up of the device’s nozzle system is shown;

[0026] Fig.12 is a schematic overview of an upstream portion of an apparatus for producing airlaid blanks according to another embodiment;

[0027] Fig.13 yes Fig.12 A close-up of the device’s nozzle system is shown;

[0028] Fig.14 is a schematic overview of an apparatus for producing an airlaid blank according to one embodiment, showing the airlaid blank in longitudinal cross-section; and

[0029] Fig.15 is a schematic overview of an apparatus for producing an airlaid blank according to another embodiment, showing the airlaid blank in longitudinal cross-section. DETAILED DESCRIPTION

[0030] Embodiments of the present invention generally relate to airlaid blanks, methods and apparatus for producing such airlaid blanks and, in particular, airlaid blanks suitable for producing cushioning inserts.

[0031] The airlaid blanks of the embodiments of the present invention can be used to produce cushioning inserts (also referred to as cushioning inlays or cushioning elements in the art) for packaging products, articles, or goods. These cushioning inserts can then be used as more environmentally friendly alternatives to corresponding cushioning inserts made of or from foamed polymers (e.g., expanded polystyrene (EPS) or foamed polyurethane (PU)). More sustainable alternatives to cushioning inserts based on EPS or PU have been proposed in the art, such as U.S. Patent Application No. 2010 / 0190020, European Patent No. 1 446 286, and International Application No. 2014 / 142714, all of which involve using a matching rigid mold or hot pressing a porous fiber mat produced by a process called airlaid into a three-dimensional insert by film molding. A significant limitation of these prior art inserts is that they are designed to protect specific products or goods. Therefore, the design of the matching mold is selected based on the shape and size of the specific product or goods to be protected by the cushioning insert. This is in stark contrast to embodiments of the present invention, which produce a universal cushioning insert that can be used to protect products and goods of various shapes and sizes. Such universal cushioning inserts are particularly desirable for companies that offer or package a variety of different products and goods, such as e-commerce companies.

[0032] The cushioning insert of an embodiment of the present invention is formed by an airlaid blank comprising natural fibers and a polymer binder. The airlaid blank (sometimes also referred to as a drylaid blank, airlaid pad, drylaid pad, airlaid web or drylaid web) is formed by a process called airlaying, in which natural fibers and a polymer binder are mixed with air to form a porous fiber mixture that is deposited on a carrier and consolidated or bonded by heating. The airlaid blank is characterized in that it is porous, has the characteristics of an open-cell foam, and is produced in a so-called dry forming method, i.e., water is usually not added. The airlaid process was originally described in U.S. Patent No. 3,575,749.

[0033] Figure 1 1 is a cross-sectional view of a portion of an airlaid blank 10. This airlaid process typically produces an airlaid blank 10 in which the vast majority of the natural fibers are oriented with their long axes approximately parallel to the major surfaces 11, 12 ( Figure 1 The xy plane in the figure), where very few fibers are oriented perpendicular to this plane, i.e., along Figure 1 Thus, the fiber structure of the airlaid blank 10 becomes almost stratified or layered in a plane perpendicular to the z-axis. Figure 1 The layered fiber orientation of the airlaid blank 10 shown is beneficial to the strength and stiffness properties of the airlaid blank 10, thereby enabling a cushioning insert having desirable strength and stiffness properties to be produced from the airlaid blank 10.

[0034] One aspect of the present invention relates to an airlaid blank 10, see Figure 2 and 5 The cross-sectional view and Figures 3A to 3C . The airlaid blank 10 comprises natural fibers and a polymer binder. The airlaid 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 airlaid blank 10, while the frame portion 15 lacks any cavities extending into the airlaid blank 10. The frame portion 15 further surrounds the cushioning portion 14.

[0035] The airlaid blank 10 thus comprises an inner portion (buffer portion 14 ) and a peripheral portion (frame portion 15 ). The buffer portion 14 comprises a plurality of cavities 13 in the airlaid blank 10 extending into the buffer portion 14 . Figure 2 One such cavity 13 is shown, and Figure 5 A plurality of cavities 13 are shown in the buffer portion 14. The cavities 13 may be viewed as holes or channels, particularly closed channels, extending from one major surface 11 of the airlaid blank 10 to the opposite major surface 12 of the airlaid blank 10.

[0036] Due to the presence of the plurality of cavities 13, the cushioning portion 14 of the airlaid blank 10 contains less natural fiber material than the frame portion 15. This means that such cushioning portion 14 of the airlaid blank 10 is more easily deformed than the more rigid frame portion 15 and will thereby be formed in the cushioning inserts 60A, 60B formed from the airlaid blank 10 (see Figure 6 and 7 ) deforms and adapts to the specific shape and size of the product or goods 70 to be packaged in and protected by the cushioning inserts 60A, 60B. The frame portion 15 lacking the cavity 13 provides structural integrity for the airlaid blank 10 and the formed cushioning inserts 60A, 60B. In addition, the frame portion 15 also constitutes shock absorption and damping protection for the packaged products or goods 70.

[0037] In one embodiment, the plurality of cavities 13 extend through a portion of the thickness of the airlaid blank 10 from the first major surface 11 of the airlaid blank 10 to the second opposite major surface 12 of the airlaid blank 10. However, in a specific embodiment, the plurality of cavities 13 do not extend through the full thickness of the airlaid blank 10, such as Figure 2 and 5As shown. Therefore, the cavity 13 preferably extends from the first major surface 11 downward to only a portion of the thickness. In one embodiment, the cavity 13 or at least a majority of the plurality of cavities 13 extends downward from the major surface 11 to a certain percentage of the thickness of the air-laid blank 10. In a specific embodiment, the percentage is selected in the interval of 25% to 90%, preferably in the interval of 35% to 90%, more preferably in the interval of 50% to 90%, such as 60% to 80%. In an illustrative but non-limiting example, the cavity 13 or at least a majority of it extends from the first major surface 11 downward to two-thirds to three-quarters of the thickness of the air-laid blank 10.

[0038] In one embodiment, at least most of the plurality of cavities 13 extend through only a portion of the thickness of the airlaid blank 10, but not through the full thickness. In such an embodiment, at least some of the cavities 13 may pass through, extend through the full thickness of the airlaid blank 10, and thereby form a channel through the airlaid blank 10 from the first major surface 11 to the second major surface 12. However, it is generally preferred that all or at least most of the cavities 13 extend through only a portion, but not through the full thickness. The reason for this is that the cushioning portion 14 will then contain a bottom 17 containing natural fibers and a polymer binder, which will also be Figure 7 The lower cushioning insert 60A in the embodiment provides cushioning support and protection for products and goods from "below" and from "above" the upper cushioning insert 60B.

[0039] 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. However, the embodiment is not limited thereto. On the contrary, the cavities 13 may have different depths in the airlaid blank 10, thereby presenting a distribution of different depths. For example, the depth of the cavities 13 into the airlaid blank 10 may be greater (deeper) in the central portion of the buffer portion 14 to provide the highest deformability in the central portion, while the depth of the cavities 13 decreases toward the frame portion 15, thereby providing greater structural support and rigidity at the more peripheral portions of the airlaid blank 10. In such an embodiment, the depth of the plurality of cavities 13 generally decreases when traveling from the center of the buffer portion 14 toward the frame portion 15. In another embodiment, the depth of the plurality of cavities 13 generally increases when traveling from the center of the buffer portion 14 toward the frame portion 15.

[0040] As further described herein, the plurality of cavities 13 may be formed by applying pulses of gas to the airlaid blank 10, or more specifically to the unbonded or unbonded airlaid web 30 that is formed into the airlaid blank 10 by heat treatment (see Fig.14), and in particular applied to the first major surface 11, 31 of the airlaid blank 10 or the unbonded airlaid web 30. The depth of the cavity 13 into the airlaid blank 10 depends on the force of the gas pulse. The depth can range from shallow indentations in the first major surface 11 to deep holes.

[0041] In one embodiment, the force of the gas pulse is controlled so as not to form any channels through the full thickness of the airlaid blank 10, but to form cavities 13 in the airlaid blank 10. The force of the gas pulse can also be controlled to achieve different depths of the cavities 13 in different parts of the buffer portion 14.

[0042] The application of the gas pulses causes the natural fiber material 38 to pile up onto the frame portion 35 and also partially onto the portion 36 of the buffer portion 34 between the cavities 33 in the unbonded airlaid web 30, as shown in FIG. Figure 4 This stacked natural fiber material 38 will be flattened during the production process, thereby causing at least a portion 19 of the frame portion 15 to be densified, such as Figure 5 As shown. This means that the average density of the frame portion 15 is higher than the average density of the airlaid blank 10 before the plurality of cavities 13 are formed in the buffer portion 14. In other words, the average density of the airlaid material in the frame portion 15 is higher than the average density of the airlaid material in the buffer portion 14. Therefore, the natural fiber material 38 blown away from the buffer portion 34 that is not combined with the airlaid web 30 will be deposited at the frame portion 35 and will then be pushed into the frame portion 35. This means that, compared with other portions of the airlaid blank 10, the corresponding frame portion 15 of the airlaid blank 10 will thereby become denser, that is, have a higher natural fiber density. The higher density further improves the structural and stiffness properties of the frame portion 15.

[0043] The plurality of cavities 13 in the buffer portion 14 may be distributed to form a regular pattern, such as a predetermined pattern, in the air-laid blank 10. Figure 3A Compared to a regular grid or matrix, a denser distribution or pattern of multiple cavities 13 can also be formed (which is in Figure 3B and 3C ). Figure 3B and 3C In the embodiment, the cavities 13 are distributed in rows or columns shifted relative to each other to reduce the distance between adjacent cavities 13 in the buffer portion 14. Figure 3C The distribution of cavities 13 is shown, wherein the cavities 13 at least partially overlap or nearly overlap. This distribution of cavities 13 significantly reduces the amount of air-laid material in the cushioning portion 14, thereby forming pillars or protruding structures 16 in the cushioning portion 14 (see Figure 5This, in turn, results in a very deformable and flexible cushioning insert 60A that adapts well to the shape and size of any product or cargo 70 placed on the cushioning portion 64 of the cushioning insert 60A (see Figure 6 ).

[0044] In one embodiment, the distance between adjacent cavities 13 in the buffer portion 14 is less than twice the maximum side length or diameter of the adjacent cavities 13. In a specific embodiment, the distance is equal to or less than 1.75 times or 1.5 times the maximum side length or diameter of the adjacent cavities 13.

[0045] In another embodiment, if there are cavities 13 of different sizes, the distance between adjacent cavities 13 in the airlaid blank 10 (i.e., in the buffer portion 14 of the airlaid blank 10) is less than twice the average side length or average diameter of the plurality of cavities 13, or less than twice the maximum side length or diameter. In a specific embodiment, if there are cavities 13 of different sizes, 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 maximum side length or diameter.

[0046] The distance between adjacent cavities 13 is defined as the center-to-center distance of adjacent cavities 13 parallel to the first and second major surfaces 11, 12. Therefore, in one embodiment, the distance between the edges of adjacent cavities 13 in the buffer portion 14 is preferably less than the maximum side length or diameter of the adjacent cavities 13. In another embodiment, if there are cavities of different sizes, the distance between adjacent cavities 13 in the buffer portion 14 is preferably less than the average side length or average diameter of the plurality of cavities 13, or less than the maximum side length or diameter.

[0047] In fact, the distance between adjacent cavities 13 in the buffer portion 14 can be even shorter. For example, and as mentioned previously, the cavities 13 can actually at least partially 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 a portion of the plurality of cavities 13. Such an embodiment is shown in Figure 3D In which the cavities 13 overlap. In this case, a plurality of protruding structures 16 will be formed between the overlapping cavities 13 by the remaining air-laid material, which is further described herein.

[0048] The (center-to-center) distance between adjacent cavities 13 may be substantially the same throughout the cushioning portion 14. In another embodiment, a portion of the cushioning portion 14 may have a denser distribution of cavities 13 than another portion of the cushioning portion 14. For example, the distance between adjacent cavities 13 may be shorter at the center of the cushioning portion 14 than at the periphery of the cushioning portion 14 near 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 toward the frame portion 15.

[0049] The frame portion 15 surrounds the buffer portion 14 (eg Figures 3A to 3C 14. This means that the plurality of cavities 13 are framed and surrounded by a portion of the airlaid blank 15 that does not contain cavities.

[0050] In one embodiment, the 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. As used herein, the width of the frame portion 15 corresponds to the distance from the edge of the air-laid blank 10 to the buffer portion 14, such as Figure 3A Indicated by W in .

[0051] In one 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 the percentage is in the interval of 2.5% to 30%, preferably in the interval of 2.5% to 25%, and more preferably in the interval of 5% to 25%, such as in the interval of 7.5% to 25%, in the interval of 10% to 25%, or in the interval of 10% to 20%.

[0052] In one embodiment, the cushioning portion 14 comprises a bottom 17 containing natural fibers and a polymer binder and a plurality of protruding structures 16 containing natural fibers and a polymer binder. The protruding structures 16 can then be separated from each other and only interconnected by the bottom 17 of the cushioning portion 14. In this case, the cavities 13 overlap at least partially. In such an embodiment, the protruding structures 16 form pillars extending from the bottom 17. In another embodiment, the protruding structures 16 can be interconnected with adjacent protruding structures 16 with (thin) walls of natural fibers and polymer binder. In the latter embodiment, adjacent cavities 13 do not overlap, but are separated by (thin) parts of air-laid material. It is also possible to combine these embodiments, i.e., to have both separate protruding structures 16 and protruding structures 16 interconnected with (thin) walls, and thus have a combination of overlapping cavities 13 and non-overlapping cavities 13.

[0053] In one embodiment, the cavity 13 may have an average extension parallel to the first and second main surfaces 11, 12, such as an average side length or an average diameter, preferably not more than 100 mm, preferably not more than 75 mm, and more preferably not more than 50 mm, such as equal to or less than 40 mm, equal to or less than 30 mm or equal to or less than 25 mm.

[0054] The cavities 13 may have substantially the same extension, such as side length or diameter, or the airlaid blank 10 may include cavities 13 of different sizes with different extensions (such as different side lengths or diameters). In addition, the overall shape of the cavities 13 may be substantially the same, such as having a cylindrical shape as an illustrative non-limiting example. However, the embodiments are not limited thereto. Therefore, the buffer portion 14 of the airlaid blank 10 may include cavities 13 having different overall shapes and forms.

[0055] It is generally preferred if the natural fibers in the airlaid blank 10 are short, at least compared to the fibers in glass or mineral wool. Having relatively short natural fibers facilitates the formation of a porous airlaid blank 10. In more detail, such short natural fibers are suitable for use in embodiments of the present invention to apply gas pulses to the airlaid blank 10 to create cavities 13 in the cushioning portion 14 of the airlaid blank 10.

[0056] The length of fibres (such as natural fibres) as referred to herein is the length weighted average fibre length. The length weighted average fibre length is calculated as the sum of the squares of the individual fibre lengths divided by the sum of the individual fibre lengths as described in, for example, ISO 16065-1:2014 Pulps — Determination of fibre length by automated optical analysis — Part 1: Polarized light method or ISO 16065-2:2014 Pulps — Determination of fibre length by automated optical analysis — Part 2: Unpolarized light method.

[0057] In one embodiment, the natural fibers have a length-weighted average fiber length of up to 10 mm, preferably up to 8 mm, more preferably up to 6 mm, and most preferably up to 5 mm. In a specific embodiment, the natural fibers have a length-weighted average fiber length selected in the interval of 1 mm up to 10 mm, preferably selected in the interval of 1 mm up to 8 mm, more preferably selected in the interval of 1 mm up to 6 mm, and most preferably selected in the interval of 1 mm up to 5 mm.

[0058] A small proportion of longer fibers having a length-weighted average fiber length of 10 mm or more may be included.

[0059] In one embodiment, the airlaid blank 10 comprises natural fibers at a concentration of at least 70% by weight of the airlaid blank 10 and a polymer binder at a concentration selected within the range of 2.5 up to 30% by weight of the airlaid blank 10.

[0060] In a preferred embodiment, the airlaid blank 10 comprises 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 airlaid blank 10. In some applications, even higher concentrations of 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 airlaid blank 10.

[0061] In some embodiments, the airlaid blank 10 contains a polymer binder selected in a concentration ranging from 5 to 30% by weight of the airlaid blank 10, preferably in a range of 10 to 25%, such as 12.5 to 22.5% by weight of the airlaid blank 10, or in a range of 15 to 20% by weight of the airlaid blank 10, or in a range of 17.5 to 22.5% by weight of the airlaid blank 10.

[0062] In other embodiments, the air-laid blank 10 contains a polymer binder selected in a concentration ranging from 2.5 to 15% by weight of the air-laid blank 10, preferably ranging from 2.5 to 12.5% ​​by weight of the air-laid blank 10, and more preferably ranging from 2.5 to 10% by weight of the air-laid blank 10, such as ranging from 2.5 to 7.5% by weight of the air-laid blank 10.

[0063] In one embodiment, natural fiber is or comprises wood fiber. In one embodiment, natural fiber is or comprises cellulose and / or lignocellulosic fiber. Therefore, in one embodiment, natural fiber contains cellulose, such as in the form of cellulose and / or lignocellulosic, i.e. a mixture of cellulose and lignin. Natural fiber may also contain lignin, such as in the form of lignocellulose. Natural fiber may additionally contain hemicellulose. In a specific embodiment, natural fiber is cellulose and / or lignocellulosic pulp fiber produced by chemical, mechanical and / or chemical-mechanical pulping of softwood and / or hardwood. For example, cellulose and / or lignocellulosic pulp fiber is in the form selected from the following: kraft pulp, sulfite pulp, thermomechanical pulp (TMP), high temperature thermomechanical pulp (HTMP), mechanical fiber (MDF-fiber) intended for medium density fiberboard, chemical-thermomechanical pulp (CTMP), high temperature chemical-thermomechanical pulp (HTCTMP), and combinations thereof.

[0064] Natural fibers (such as cellulose and / or lignocellulosic pulp fibers) can be bleached or unbleached.

[0065] Natural fibers may also be produced by other pulping processes and / or from other cellulosic or lignocellulosic raw materials such as flax, jute, hemp, kenaf, bagasse, cotton, bamboo, straw or rice husks. Natural fibers that are mixtures of fibers from different raw materials (such as mixtures of wood and any of the materials mentioned above) may also be used.

[0066] The airlaid blank 10 may also include a small portion of synthetic materials or fibers mixed with natural fibers. Such synthetic materials or fibers that may be mixed with natural fibers include, for example, glass or mineral wool, and / or carbon fibers. Any such synthetic materials or fibers may be added in an amount of no more than 10% (wt / wt) of the airlaid blank 10, preferably no more than 8% (wt / wt) of the airlaid blank 10, such as no more than 6% (wt / wt), or preferably no more than 4% (wt / wt).

[0067] A polymeric binder is included in the airlaid blank 10 to bind the airlaid blank 10 together and maintain its form and structure during use, handling and storage. In one embodiment, the polymeric binder may also help to build the foam-like structure of the airlaid blank 10. In such embodiments, the polymeric binder is intertwined with the natural fibers during the airlaid process to form a fiber mixture. The polymeric binder can be added in powder form, but is more typically added in the form of fibers that are intertwined with the natural fibers during the airlaid process. Alternatively or in addition, the polymeric binder may be added to and onto the airlaid blank 10 as a solution, emulsion or dispersion during the airlaid process, such as in combination with the following. Fig.15 Further described.

[0068] In a particular embodiment, the polymer binder is selected from the group consisting of polymer powders, polymer fibers, and combinations thereof.

[0069] The polymer binder may 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.

[0070] In one embodiment, the polymer binder is made of: i) a material selected from 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), polyvinyl pyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyvinyl acetate (PVAc), polyurethane (PU), their copolymers and their mixtures, and ii) optionally one or more additives.

[0071] Thus, in one embodiment, the polymer binder is made of a material selected from the above mentioned group.In another embodiment, the polymer fiber is made of a material selected from the above mentioned group and one or more additives.

[0072] In one embodiment, the polymer binder is a thermoplastic polymer binder, and is preferably selected from the group consisting of thermoplastic polymer powders, thermoplastic polymer fibers, and combinations thereof.

[0073] In one embodiment, the polymer binder is or comprises, such as consisting of, a monocomponent and / or bicomponent thermoplastic polymer fiber. Bicomponent thermoplastic polymer fibers (also referred to as bico fibers) comprise a first polymer, copolymer, and / or polymer blend, and a second, different polymer, copolymer, and / or polymer blend. Most often, the bicomponent thermoplastic polymer fiber comprises a core made of a first polymer, copolymer, and / or polymer blend, and a sheath made of a second polymer, copolymer, and / or polymer blend, although combinations of two or even more polymers, copolymers, and / or polymer blends are possible.

[0074] In a specific embodiment, the thermoplastic polymer binder is or comprises, such as consists of, a monocomponent thermoplastic polymer fiber made of: i) a material selected from 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 specific embodiment, the thermoplastic polymer binder is or comprises, such as consists of, a bicomponent thermoplastic polymer fiber having a first material, such as a core made of: i) a first material selected from 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 from: i) a second material selected from PE, EAA, EVA, PP, PS, PBAT, PBS, PLA, PET, PCL, PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, PVAc, PU, ​​copolymers thereof and mixtures thereof, typically a different material, and ii) optionally one or more additives. In another embodiment, the thermoplastic polymer binder is or comprises, such as consisting of, a combination or mixture of: a monocomponent thermoplastic polymer fiber 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 a bicomponent thermoplastic polymer fiber having i) a material (such as 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.

[0075] The thermoplastic polymer binder can be made of a single type of thermoplastic polymer fiber, i.e., made of the same material in the case of monocomponent thermoplastic polymer fibers, or made of the same material in the case of bicomponent thermoplastic polymer fibers. However, it is also possible to use a thermoplastic polymer binder made of one or more (i.e., two or more) different monocomponent thermoplastic polymer fibers made of different materials and / or one or more different bicomponent thermoplastic polymer fibers made of different materials.

[0076] One advantage of using bicomponent thermoplastic polymer fibers is that they can have a higher melting point core that maintains its fiber form during the bonding operation, while the sheath melts and becomes tacky. The intact core will support the three-dimensional structure of the airlaid blank 10 and thus promote porosity, while the molten or tackified sheath will adhere to the natural fibers and maintain the strength of the airlaid blank 10.

[0077] In one embodiment, the polymer binder is a polymer powder, preferably a thermoplastic polymer powder, made of: i) a material selected from PE, EAA, EVA, PP, PS, PBAT, PBS, PLA, PET, PCL, PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, PVAc, PU, ​​their copolymers and their mixtures, and ii) optionally one or more additives.

[0078] As mentioned previously, it is also possible to use a thermoplastic polymer binder that is a combination of thermoplastic polymer fibers and thermoplastic polymer powder.

[0079] In addition to natural fibers and polymeric binders, the airlaid blank 10 may also include one or more additives. One or more additives may be added to the polymeric binder and / or added when the polymeric binder is produced. Alternatively or in addition, one or more additives may be added to natural fibers. Alternatively or in addition, one or more additives may be added to natural fibers and polymeric binders, such as during the airlaid process or before the airlaid process.

[0080] Illustrative but non-limiting examples of such additives include conductive or semiconductive fillers, coupling agents, flame retardants, dyes, impact modifiers, and the like.

[0081] In a particular embodiment, the polymer binder is a natural polymer selected from starch, agar, guar gum, locust bean gum, carrageenan, and cellulose, such as fibrillar, microfibrillar or nanofibrillar cellulose.

[0082] In one embodiment, the polymer binder may be in the form of a water-based (aqueous) solution, emulsion, suspension, or dispersion of the polymer binder.

[0083] Another aspect of the present invention relates to a method of producing an airlaid blank 10, see Figure 8 as well as Figure 10-14 , which shows an embodiment of an apparatus 100 for generating an airlaid blank 10. The method comprises introducing natural fibers and a polymer binder and / or a mixture of natural fibers and a polymer binder into at least one inlet 111 of a forming head 110 in step S1. The method further comprises conveying the natural fibers and the polymer binder and / or the mixture to an outlet 113 of the forming head 110 in step S2. The method further comprises capturing the natural fibers and the polymer binder and / or the mixture as an unbonded airlaid web 30 on a collector 120 arranged to be connected to the outlet 113 of the forming head 110 in step S3. The method additionally comprises applying a gas pulse to the unbonded airlaid web 30 in step S4 to form a buffer portion 34 comprising a plurality of cavities 33 extending into the unbonded airlaid web 30. The buffer portion 34 is surrounded by a frame portion 35 of the unbonded airlaid web 30, and the frame portion 35 lacks any cavities extending into the unbonded airlaid web 30. The method further comprises heat treating the unbonded airlaid web 30 in step S5 to at least partially melt the polymer binder and form the airlaid blank 10 .

[0084] In one embodiment, step S5 includes heat treating the unbonded airlaid web 30 to at least partially melt the polymer binder and form an airlaid blank 10 comprising a buffer portion 14 containing a plurality of cavities 13 extending into the airlaid blank 10 and a frame portion 15 lacking any cavities extending into the airlaid blank 10. The frame portion 15 surrounds the buffer portion 14.

[0085] The conveying or passing of the natural fibers and polymer binder and / or mixture in the forming head 110 in step S2 facilitates separation into individual fibers to thereby promote the porous unbonded air-laid web 30 on the collector 120 .

[0086] The equipment 100 for producing air-laid blank 10 comprises a forming head 110, also referred to as a forming chamber in the art. Natural fibers and polymer binders are input or introduced into the forming head 110 at one or more inlets 111 as one or more discrete input streams and / or as one or more mixed input streams. For example, as connected with its upper end 112 or further below in the forming head 110, the forming head 110 can comprise a flow inlet for natural fibers and a flow inlet for polymer binders. In another embodiment, the forming head 110 comprises a plurality of flow inlets for natural fibers and a flow inlet for polymer binders, a flow inlet for natural fibers and a plurality of flow inlets for polymer binders, or a plurality of flow inlets for natural fibers and a plurality of flow inlets for polymer binders. In these illustrative examples, natural fibers and polymer binders are mixed and blended during conveying through or passing through the forming head 110, and finally form the air-laid blank 10 on the collector 120.

[0087] Alternatively or in addition, one or more input streams of natural fibers and / or one or more input streams of polymer binder, a preformed mixture of natural fibers and polymer binder may be introduced into the forming head 110 at one or more stream inlets 111 .

[0088] The forming head 110 may include equipment disposed within the forming head 110 to facilitate separation and mixing of the natural fibers and the polymeric binder, and / or mixtures thereof, during transport through or past the forming head 110. Such equipment may include, for example, rollers with interlocking pins, one or more drums such as a slot drum, and / or one or more filters.

[0089] In one embodiment, the collector 120 is an air permeable collector 120. In such embodiments, step S3 includes capturing the natural fibers and polymer binder and / or mixture onto the air permeable collector 120 with a vacuum applied thereto.

[0090] The natural fibers and polymer binder and / or mixture thereof are transported upwardly to the forming head 110 by air and enter the forming head 110 in at least one inlet 111, which is arranged, for example, in connection with an upper end 112 of the forming head 110, or further below the forming head 110. The natural fibers and polymer binder and / or mixture thereof are then transported through the forming head 110 to an outlet 113, which is arranged, for example, in connection with a lower end 114 of the forming head 110. The natural fibers and polymer binder and / or mixture are then at least partially captured on the permeable collector 120, which is arranged in connection with the outlet 113 of the forming head 110, by a vacuum, i.e., extraction of air or under pressure, applied thereto.

[0091] Thus, the vacuum applied to the permeable collector 120 draws the natural fibers and polymer binder and / or mixtures thereof down onto the permeable collector 120 .

[0092] The collector 120 is preferably air permeable to allow a vacuum to be applied thereto and to draw the natural fibers and polymer binder onto the air permeable collector 120. For example, the air permeable collector 120 may include a plurality of openings, through-holes, or channels to allow air to be sucked or drawn through the air permeable collector 120. As an illustrative but non-limiting example, the air permeable collector 120 may be a mesh collector 120 containing a plurality of tiny through-holes. However, any such openings are preferably small enough to prevent the natural fibers and polymer binder from passing through the air permeable collector 120. Thus, the natural fibers and polymer binder are instead deposited onto the air permeable collector 120 as a mixture in the form of an unbonded airlaid web 30.

[0093] The collector 120 may be a plate, disk, mesh or similar planar collector 120 that is arranged to be connected to the outlet 113 of the forming head 110. Once the unbonded air-laid web 30 is formed on the collector 120, the collector 120 may transfer the unbonded air-laid web 30 positioned thereon from the forming head 110 to be subjected to a gas pulse at the nozzle system 130.

[0094] In another embodiment capable of continuously producing the airlaid blank 10, the collector 120 may be a Fig.14 The belt or wire collector 120 shown running between drive rollers 122, 124 is preferably in the form of an air-permeable belt or wire collector 120. Such an air-permeable belt or wire collector 120 is also referred to as an air-permeable belt or wire conveyor 120. In such embodiments, step S4 includes applying a gas pulse to the unbonded air-laid web 30 on the belt collector 120 positioned downstream of the forming head 110.

[0095] Downstream relates to the direction of movement of the belt collector 120 from the drive roller 122 to the drive roller 124. Thus, once the unbonded airlaid web 30 has left the forming head 110, a gas pulse is applied to the unbonded airlaid web 30 in step S4.

[0096] In one embodiment, the gas pulses are applied in step S4 by selectively applying gas pulses using a plurality of fixed gas nozzles 132, such as one or more rows, see Fig.11 and 13, arranged downstream of the forming head 110. Alternatively or additionally, in step S4, gas pulses may be selectively applied using at least one movable gas nozzle 132, which is arranged downstream of the forming head 110 and is selectively movable relative to the unbonded air-laid web 30 positioned on the belt collector 120.

[0097] Fig.11 and 13 A nozzle system 130 is schematically shown, which includes nozzles along the width ( Fig.11 ), or at least along a portion of the width of the unbonded airlaid web 30 ( Fig.13 ) are distributed in a plurality of gas nozzles 132. These gas nozzles 132 can then be used to selectively apply gas pulses in step S4 to form cavities 33 in the unbonded airlaid web 30. As used herein, selectively applying means that in one embodiment, the gas nozzles 132 are controlled by the controller 140 (see Fig.10 and 12 ) to apply gas pulses at selected time instances or time periods as the unbonded airlaid web 30 moves past the nozzle system 130 above the belt collector 120. In such an embodiment, the gas nozzles 132 may extend across a majority of the width of the unbonded airlaid web 30 (e.g., Fig.10 30) to prevent the formation of cavities 33 in the peripheral portion of the unbonded airlaid web 30 that forms part of the frame portion 35. In another embodiment, the gas nozzles 132 are provided as a plurality of groups (e.g., Fig.12 and 13 ), where there are gaps between adjacent groups of gas nozzles 132. Such a method can produce a side-by-side buffer portion 34 with a middle frame portion 35 in the unbonded airlaid web 30. All of the gas nozzles 132 can then be operated by the controller 140 to apply gas pulses simultaneously.

[0098] In another embodiment, the controller 140 can 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 to generate a more or less regular pattern of cavities 33, such as a matrix or a grid, in the unbonded airlaid web 30. This embodiment also enables to control the width of the frame portion 35 in the unbonded airlaid web 30.

[0099] exist Figures 10 to 13In the embodiment, a single row of gas nozzles 132 is arranged above the belt collector 120. However, the embodiment is not limited thereto. In contrast, multiple rows of such gas nozzles 132 may be arranged relative to the collector 120. In this case, the gas nozzles 132 may be arranged in a matrix or grid. Multiple rows of gas nozzles 132 may also be shifted relative to each other to form a pattern of the cavity 33, such as Figure 3B Or as shown in 3C.

[0100] Instead of or in addition to the nozzle system 130 having fixed gas nozzles 132, one or more movable gas nozzles 132 may be arranged downstream of the forming head 110. In this case, the controller 140 may control at least one movable gas nozzle 132 to move relative to the unbonded airlaid web 30 and selectively apply gas pulses to the unbonded airlaid web 30. In this case, the at least one movable gas nozzle 132 is preferably movable at least along the width of the unbonded airlaid web 30.

[0101] The heat treatment applied in step S5 performs a bonding operation wherein the unbonded airlaid web 30 is introduced into a bonding oven 150 (see Fig.14 ), wherein heat, for example in the form of heated air, is circulated through the unbonded airlaid web 30 to melt or partially melt the polymer binder. The polymer binder thereby becomes tacky and adheres to the natural fibers, thereby binding the fibrous material together and thereby resulting in an airlaid blank 10.

[0102] The heat treatment of step S5 causes the polymer binder to at least partially melt, so as to become tacky and adhere to the natural fibers in the unbonded airlaid web 30. Thus, the natural fibers and the polymer binder are bonded together and form the airlaid blank 10. This heat treatment in step S5 preserves the cavities 33 formed in step S4 by applying the gas pulses. Thus, the airlaid blank 10 comprises a buffer portion 14 comprising a plurality of cavities 13 surrounded or surrounded by a frame portion 15.

[0103] The bonding operation may also include and / or be accompanied by densification to form a greater number of bonding points in the fiber structure and, thus, to form a stronger and more dense air-laid blank 10. This densification operation may be applied after the bonding oven 150, before the air-laid blank 10 has been allowed to cool, or when heating is restarted, such as in a heated calender. The densification operation may also be performed in the bonding oven 150, for example, as a combined heating and densification operation. In the latter case, step S5 includes heat treating the unbonded air-laid web 30 to at least partially melt the polymer adhesive, and simultaneously applying pressure to the unbonded air-laid web 30 to form the air-laid blank 10. Densification may include various types of operations, including but not limited to calendering and / or pressing operations. Figure 5 Schematically shows Figure 4 A cross-sectional view of the airlaid blank 10 after heat treatment and densification without bonding the airlaid web 30 is shown. Figure 5 As shown, a plurality of cavities 13 remain in the airlaid blank 10 after the heat treating and densification operations.

[0104] In the above-described embodiment, the airlaid blank 10 is produced by introducing both natural fibers and a polymer binder into a forming head 110 . Fig. 9 is a flow chart showing another embodiment of a method for producing an airlaid blank 10, see also Fig.15 The method includes introducing natural fibers into at least one inlet 111 of a forming head 110 in step S10. The method also includes delivering the natural fibers to an outlet 113 of the forming head 110 in step S11 and capturing the natural fibers as a web 40 of natural fibers on a collector 120 arranged to be connected to the outlet 113 of the forming head 110 in step S12. The method further includes applying a gas pulse to the web 40 of natural fibers on the collector 120 in step S13 to form a buffer portion 44 including a plurality of cavities 43 extending into the web 40 of natural fibers. The buffer portion 44 is surrounded 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 includes applying a polymer binder to the natural fibers in step S14. The method additionally comprises heat treating S15 the web of natural fibers 40 and the polymer binder to form the airlaid blank 10 in step S15 .

[0105] In one embodiment, step S15 includes heat treating S15 the web 40 of natural fibers and the polymer binder to form an airlaid blank 10 comprising a buffer portion 14 containing a plurality of cavities 13 extending into the airlaid blank 10 and a frame portion 15 lacking any cavities extending into the airlaid blank 10. The frame portion 15 surrounds the buffer portion 14.

[0106] This embodiment of the method is combined with the above Figure 8 The method discussed differs in that no polymer binder is introduced into the forming head 110 in step S10. In sharp contrast, in step S10, one or more streams of natural fibers and / or mixtures thereof are introduced through one or more inlets 111 in the forming head 110. In step S11, the natural fibers are conveyed through or past the forming head 110 and then captured on a collector as a web 40 of natural fibers in step S12. The web 40 is then collected in step S13 in a manner similar to that of the web 40 of natural fibers. Figure 8 Gas pulses are applied to the web 40 of natural fibers in a manner as in step S4 in order to form cavities 43 in the web 40 of natural fibers. In this embodiment, a polymer binder is then applied to the web 40 of natural fibers in step S14 before exposing the web 40 of natural fibers and the polymer binder to heat in a downstream bonding oven 150 in step S15.

[0107] Therefore, 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 a polymeric binder. In step S14, the device 160 can apply the polymeric binder as, for example, a solution, an emulsion, a suspension or a dispersion to and on the web 40 of natural fibers. For example, the polymeric binder can be sprayed onto the web 40 of natural fibers in step S14. In an exemplary embodiment, the polymeric binder is in the form of a water-based (aqueous) solution, emulsion, suspension or dispersion of at least one polymeric binder in the form of one or more synthetic polymers and / or one or more natural polymers. In this case, the polymeric binder can be selected from the polymeric binder materials described previously.

[0108] Fig. 9 The subsequent step S15 in Figure 8 The heat treatment applied in step S15 in the bonding oven 150 may be performed in the same manner as step S5 in step S14. However, depending on the material of the polymer binder applied in step S14, the heat treatment applied in step S15 may not necessarily at least partially melt the polymer binder, but if the polymer binder is in the form of a water-based solution, emulsion, suspension or dispersion, water may be dried off to form the air-laid blank 10. This drying operation is also applicable to the use of a solvent other than water for the polymer binder.

[0109] The various embodiments of steps S1 to S5 described above can be applied with necessary changes to the following examples: Fig. 9 The method is shown with the exception that no polymer binder is introduced in step S10.

[0110] It is also possible to combine the two described embodiments shown in 8 and 9. Thus, the polymer binder can be introduced into the forming head (as above in combination with Figure 8 Additional polymeric binder may then be applied to the unbonded airlaid web 30 (eg, Fig. 9 ), for example, to strengthen the surface of the resulting air-laid blank 10.

[0111] The above description and Figure 8 and 9 The method shown in the flow chart is suitable for producing the air-laid blank 10 (such as Figure 2 , 3 and 5). Therefore, the air-laid blank 10 is formed by the above description and Figure 8 The method shown in the flowchart of or 9 can be obtained or obtained.

[0112] Figure 8 and 9 The method disclosed in the method may also include an additional step S6 or S16, including cutting the air-laid blank 10 into cushioning inserts 60A, 60B. In a general embodiment, the air-laid blank 10 includes a plurality of cushioning portions 14 surrounded by corresponding frame portions 15. In this case, in step S6 or S16, the air-laid blank 10 is preferably cut to form a plurality of cushioning inserts 60A, 60B.

[0113] The cutting operation in step S6 or S16 can be performed using any suitable cutter or cutting device. Illustrative but non-limiting examples of such cutting devices include saws, punches, knives, etc.

[0114] The present invention also relates to a cushioning insert 60A, 60B made from an airlaid blank 10 comprising natural fibers and a polymer binder, see Figure 6 and 7 The cushioning insert 60A, 60B includes a cushioning portion 64 and a frame portion 65. The cushioning portion 64 includes 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 surrounds the cushioning portion 64.

[0115] The cushioning inserts 60A, 60B are produced from the airlaid blank 10 of the present invention, such as by Figure 8 and 9In step S6 or S16, the air-laid blank 10 is cut into a plurality of buffer inserts 60A, 60B. The buffer inserts 60A, 60B are cut into an overall size and shape suitable for the packaging box 50, such as Figure 6 and 7 as displayed.

[0116] The various embodiments described above with respect to the airlaid blank 10 are also applicable to the cushioning inserts 60A, 60B produced from the airlaid blank 10.

[0117] In one embodiment, the plurality of cavities 63 extend from the first major surface 61 of the buffer insert 60A, 60B to the second opposite major surface 62 of the buffer insert 60A, 60B through a portion of the thickness of the buffer insert 60A, 60B, but not through the full thickness of the buffer insert 60A, 60B. In one embodiment, the cavity 63 or at least a majority of the plurality of cavities 63 extend downward from the major surface 61 to a certain percentage of the thickness of the buffer insert 60A, 60B. In a specific embodiment, the percentage is selected in the interval of 25% to up to 90%, preferably in the interval of 35% to up to 90%, more preferably in the interval of 50% to up to 90%, such as in the interval of 60% to up to 80%. In an illustrative but non-limiting example, the cavity 63 or at least a majority thereof extends downward from the first major surface 61 to two-thirds to three-quarters of the thickness of the buffer insert 60A, 60B.

[0118] In one embodiment, the distance between adjacent cavities 63 in the buffer portion 64 is less than twice the maximum side length or diameter of the adjacent cavities 63. In a specific embodiment, the distance is equal to or less than 1.75 times or 1.5 times the maximum side length or diameter of the adjacent cavities 63.

[0119] In another embodiment, if there are cavities 63 of different sizes, the distance between adjacent cavities 63 in the buffer portion 64 is less than twice the average side length or average diameter of the plurality of cavities 63, or less than twice the maximum side length or diameter. In a specific embodiment, if there are cavities 63 of different sizes, 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 maximum side length or diameter.

[0120] As previously discussed, this distance is defined as the center-to-center distance of the cavity 63 parallel to the first and second major surfaces 61 , 62 of the cushioning inserts 60A, 60B.

[0121] In fact, the distance between adjacent cavities 63 in the buffer portion 64 can be even shorter. For example, the cavities 63 can actually overlap at least partially. 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 a portion of the plurality of cavities 63.

[0122] In one embodiment, the 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. As used herein, the width of the frame portion 65 corresponds to the distance from the edge of the buffer insert 60A, 60B to the buffer portion 64.

[0123] In one embodiment, the width of the frame portion 65 of the buffer insert 60A, 60B corresponds to a percentage of the width of the buffer insert 60A, 60B, and wherein the percentage is in the interval of 2.5% to 30%, preferably in the interval of 2.5% to 25%, and more preferably in the interval of 5% to 25%, such as in the interval of 7.5% to 25%, in the interval of 10% to 25%, or in the interval of 10% to 20%.

[0124] In one embodiment, the cushioning portion 64 includes a base 67 and a plurality of protruding structures 66 extending from the base 67 .

[0125] With regard to the distribution of the cavities 13,63 in the buffering parts 14,64, the buffering parts 14 of the air-laid blank 10 and thus the buffering parts 64 of the buffering inserts 60A,60B can have various shapes. For example, the buffering parts 14,64 can be square, rectangular, circular, oval or any other shape in fact. In one embodiment, the shape and / or size of the buffering parts 14,64 can at least partially depend on the shape and / or size of the product or goods 70 to be packaged in the packaging box 50 and protected by the buffering inserts 60A,60B. However, the advantage of the present invention is that the buffering inserts 60A,60B can be used to protect various products and goods 70 from vibration and impact, regardless of whether the cavities 13,63 in the buffering parts 14,64 are formed together, for example, square or circular.

[0126] The outer dimensions and shape of the cushioning inserts 60A, 60B are preferably selected based on the size and shape of the package 50 into which the cushioning inserts 60A, 60B are to be inserted, such as Figure 6 and 7 as displayed.

[0127] Therefore, one aspect of the present invention relates to a packaging assembly, which includes a packaging box 50 and a first buffer 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 buffer insert 60A according to the present invention is arranged on the bottom 53 of the packaging box 50, wherein a plurality of cavities 63 are facing away from the bottom 53 of the packaging box 50, such as Figure 6 as displayed.

[0128] In one embodiment, the packaging assembly further comprises a second cushioning insert 60B according to the present invention, see Figure 7 In such an embodiment, the second cushioning insert 60B is disposed in the packaging volume 54 with the plurality of cavities 63 facing the first cushioning insert 60A.

[0129] Any goods or products 70 to be packaged in the packaging assembly are positioned between the first cushioning insert 60A and the second cushioning insert 60B, such as Figure 7 Indicated. The cavities 63 of the two buffer inserts 60A, 60B then face each other, and the goods or products 70 are placed between them. The cavity 63 present in the buffer portion 64 of the two buffer inserts 60A, 60B makes these parts of the buffer inserts 60A, 60B deformable to accompany the goods or products 70 and adapt to the specific shape and / or size of the goods or products 70. Compared with the buffer portion 64, the surrounding frame portion 65 has no cavity and is thus more rigid and has higher structural integrity. This means that the frame portion 65 thus provides support to the buffer inserts 60A, 60B, and provides protection from vibration and impact from at least one side wall 51, 52 outside of the packaging box 50.

[0130] The packaging assembly may be used to package a single product or good 70 or a plurality of products or good 70 in the packaging box 50 .

[0131] For example, if the packaging box 50 is in the form of a cylinder with a circular or oval bottom 53, the packaging box 50 (also referred to as a container herein) can include a single sidewall attached to the bottom 53. The sidewall is then a curved sidewall surrounding the circular or oval bottom 53. In such an embodiment, the packaging box 50 is a cylindrical packaging box 50. In other embodiments, the packaging box 50 can be in the form of a cube or a cuboid. In such an embodiment, the packaging box 50 includes four sidewalls 51, 52 attached to the bottom 53.

[0132] Packing box 50 can be made of various materials, include but not limited to paper-based materials, include but not limited to paperboard materials, as cardboard materials, box paperboard materials or corrugated paperboard materials, also referred to as boxboard materials. In a specific embodiment, packing box 50 is a cardboard box or a corrugated paper box. Another kind of material of packing box 50 can be timber.

[0133] The above embodiments are to be understood as several illustrative examples of the present invention. It will be appreciated 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 partial solutions in different embodiments may 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 buffer portion (14), the buffer portion comprising a plurality of cavities (13) extending into the airlaid blank (10); and A frame portion (15) lacking any cavities extending into the airlaid blank (10), wherein the frame portion (15) surrounds the cushioning portion (14).

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

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

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

5. The airlaid 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 a portion of the plurality of cavities (13).

6. The airlaid blank according to any one of claims 1 to 5, wherein the buffer portion (14) further comprises: a base (17), said base comprising said natural fibers and said polymer binder; and A plurality of protruding structures (16) comprising the natural fibers and the polymer binder and extending from the base (17).

7. The airlaid blank according to any one of claims 1 to 6, wherein the average density of the airlaid material in the frame portion (15) is higher than the average density of the airlaid material in the buffer 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 up to 6 mm, and most preferably up to 5 mm, such as a length-weighted average fiber length selected within the interval of 1 mm to up to 10 mm, preferably within the interval of 1 mm to up to 8 mm, more preferably within the interval of 1 mm to up to 6 mm, and most preferably within the interval of 1 mm to up to 5 mm.

9. The airlaid blank according to any one of claims 1 to 8, wherein the airlaid blank (10) comprises: a concentration of at least 70% by weight of said airlaid blank (10) of said natural fibers; and The polymeric binder is selected in a concentration ranging from 2.5 up to 30% by weight of the airlaid blank (10).

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

11. The airlaid blank according to claim 10, wherein the natural fibers are cellulosic and / or lignocellulosic pulp fibers in a form selected from the group consisting of kraft pulp, sulfite pulp, thermomechanical pulp (TMP), high temperature thermomechanical pulp (HTMP), mechanical fibers intended for medium density fiberboard (MDF-fibers), chemi-thermomechanical pulp (CTMP), high temperature chemi-thermomechanical pulp (HTCTMP), and combinations thereof.

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

13. The airlaid blank according to claim 12, wherein the thermoplastic polymer fibers are selected from the group consisting of monocomponent thermoplastic polymer fibers, bicomponent thermoplastic polymer fibers, and mixtures thereof, preferably bicomponent thermoplastic polymer fibers.

14. The airlaid blank according to any one of claims 1 to 13, wherein the polymer binder is made of: i) a material selected from 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), polyvinyl pyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyvinyl acetate (PVAc), polyurethane (PU), their copolymers and their mixtures, and ii) optionally one or more additives.

15. A method for 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); delivering ( 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 unbonded airlaid web (30) on a collector (120) arranged in connection with the outlet (113) of the forming head (110); applying (S4) a gas pulse to the unbonded airlaid web (30) to form a buffer portion (34) comprising a plurality of cavities (33) extending into the unbonded airlaid web (30), wherein the buffer portion (34) is surrounded by a frame portion (35) of the unbonded airlaid web (30) and the frame portion (35) lacks any cavities extending into the unbonded airlaid web (30); and The unbonded airlaid web (30) is heat treated (S5) to at least partially melt the polymer binder and form an airlaid blank (10).

16. A method according to claim 15, wherein the heat treatment (S5) includes heat treating (S5) the unbonded air-laid web (30) to at least partially melt the polymer binder and form an air-laid blank (10), the air-laid blank comprising a buffer portion (14) containing 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) surrounds the buffer portion (14).

17. A method for producing an airlaid blank (10), the method comprising: introducing (S10) natural fibers into at least one inlet (111) of a forming head (110); delivering (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 to be connected to the outlet (113) of the forming head (110); applying (S13) a gas pulse to the web (40) of natural fibers on the collector (120) to form a buffer portion (44) comprising a plurality of cavities (43) extending into the web (40) of natural fibers, wherein the buffer portion (44) is surrounded 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 to the natural fibers; as well as The natural fiber web (40) and the polymer binder are heat treated (S15) to form an air-laid blank (10).

18. The method according to claim 17, wherein the heat treatment (S15) includes heat treating (S15) the web (40) of natural fibers and the polymer binder to form an air-laid blank (10), the air-laid blank comprising a buffer portion (14) containing 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) surrounds the buffer portion (14).

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

20. A cushioning insert (60A, 60B) made from an airlaid 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 cavity extending into the cushioning insert (60A, 60B), wherein the frame portion (65) surrounds the cushioning portion (64).

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

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

23. The buffer insert according to claim 20 or 21, wherein the distance between adjacent cavities (63) in the buffer portion (64) is less than twice the 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 a 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: bottom (67); and A plurality of protruding structures (66) extend from the base (67).

26. The cushioning insert according to any one of claims 20 to 25, made from the airlaid 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 buffer insert (60A) according to any one of claims 20 to 26, arranged on the bottom (53) of the packaging box (50), wherein the plurality of cavities (63) face away from the bottom (53) of the packaging box (50).

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

Images