Airlaid blank, method for producing an airlaid blank, and method for producing a three-dimensional product from the airlaid blank

Abstract

The airlaid blank (10) comprises natural fibers at a concentration of at least 70% by weight of the airlaid blank (10) and a thermoplastic polymer binder selected in a concentration range of 2.5 to 30% by weight of the airlaid blank (10). The airlaid blank (10) has an average density, and a portion (11) of the airlaid blank (10) has a density different from the average density. The airlaid blank (10) is produced by varying the air permeability of a portion (121) of an air permeable collector (120) to form a portion (11) of the airlaid blank (10) having a density different from the average density. The airlaid blank (10) has two parallel, planar major surfaces (12, 14).

Description

Technical Field

[0001] Embodiments of the present invention generally relate to airlaid blanks and methods of producing such airlaid blanks and three-dimensional (3D) formed products. Background Art

[0002] With growing awareness of the environment and human-induced climate change, the use of single-use plastic items and products has become increasingly questioned. However, despite these concerns, the use of these items and products has grown significantly over the past decade, driven by new trends in lifestyles and consumer habits. One reason for this is that more and more goods are being shipped around the world, and these goods need to withstand shock, vibration, and / or extreme temperatures. A common way to protect goods is to include cushioning and / or insulating elements or products, such as inserts in the packaging. These can be made from a variety of materials, but are typically made from foamed polymers, with expanded polystyrene (EPS) being by far the cheapest and most common. In some cases, the entire packaging can be made from EPS. An example is shipping boxes for food that must be kept within a specified temperature range (such as cold foods, such as fish, or hot foods, such as ready meals). However, EPS is one of the most questioned plastic materials, and many brand owners are seeking more sustainable solutions for these packaging applications. Many countries have also begun to take legislative action against single-use plastic items and products, increasing the pressure to find alternative solutions.

[0003] More sustainable alternatives to polymer products exist today, such as inserts made through a process called pulp molding, in which a fiber suspension is vacuum-drawn onto a wire mold. Another technique for forming such inserts is described in U.S. Patent Application No. 2010 / 0190020 and European Patent No. 1 446 286, both of which involve hot-pressing a porous fiber mat produced through a process called air-laying into a 3D structure using a matching rigid mold or through film molding.

[0004] However, the above-described methods provide limited shock protection and thermal insulation capabilities to the product. Therefore, there is a need in the market for 3D-formed products that are used for cushioning and / or thermal insulation of packaged goods and can be manufactured using materials that are more environmentally friendly than EPS. Summary of the Invention

[0005] One object is to provide airlaid blanks that can be used to produce cushioning and / or thermally insulating 3D shaped products for packaging goods.

[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 at a concentration of at least 70% by weight of the airlaid blank and a thermoplastic polymer binder selected in a concentration range of 2.5 to 30% by weight of the airlaid blank. The airlaid blank has an average density, and portions of the airlaid blank have densities different from the average density. The airlaid blank has two parallel, planar major surfaces.

[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 thermoplastic polymer binder and / or a mixture of natural fibers and a thermoplastic polymer binder into the upper end of a forming head. The method also includes conveying the natural fibers and the thermoplastic polymer binder and / or the mixture to the lower end of the forming head by applying a vacuum to a permeable collector, which is arranged to be connected to the lower end of the forming head. The method also includes capturing the natural fibers and the thermoplastic polymer binder and / or the mixture on the permeable collector. The method additionally includes heating the natural fibers and the thermoplastic polymer binder and / or the mixture to form the air-laid blank. The air-laid blank comprises natural fibers in a concentration of at least 70% by weight of the air-laid blank and a thermoplastic polymer binder selected in a concentration ranging from 2.5 to 30% by weight of the air-laid blank. The permeable collector has an average air permeability. The air permeability of a portion of the permeable collector is different from the average air permeability and / or the object is positioned on the portion of the permeable collector. The air permeability of the portion of the permeable collector on which the object is positioned is different from the average air permeability. The airlaid blank has an average density, and the density of the portion of the airlaid blank aligned with the portion of the permeable collector is different from the average density. The airlaid blank has two parallel planar major surfaces.

[0010] Another aspect of the present invention relates to a method for producing a 3D formed product. The method includes hot pressing a male tool into an airlaid blank to form a 3D formed product having a 3D shape at least partially defined by the male tool. The airlaid blank comprises a concentration of natural fibers of at least 70% by weight of the airlaid blank and a thermoplastic polymer binder selected in a concentration range of 2.5 to 30% by weight of the airlaid blank. The airlaid blank has an average density, and the density of a portion of the airlaid blank is different from the average density. The male tool includes a protrusion configured to be pressed into the airlaid blank, and the protrusion is configured to align with a portion of the airlaid blank having a density different from the average density of the airlaid blank during hot pressing.

[0011] Another aspect of the present invention relates to a method for producing an air-laid blank. The method includes introducing natural fibers and a thermoplastic polymer binder and / or a mixture of natural fibers and a thermoplastic polymer binder into the upper end of a forming head. The method also includes conveying the natural fibers and the thermoplastic polymer binder and / or the mixture to the lower end of the forming head, which is arranged to be connected to a belt collector running between drive rollers. The method also includes positioning the 3D object on the belt collector and capturing the natural fibers and the thermoplastic polymer binder and / or the mixture on the belt collector. The method additionally includes heating the natural fibers and the thermoplastic polymer binder and / or the mixture to form the air-laid blank. The air-laid blank comprises natural fibers at a concentration of at least 70% by weight of the air-laid blank and a thermoplastic polymer binder selected at a concentration within the range of 2.5% to 30% by weight of the air-laid blank. The air-laid blank has two parallel major surfaces and a thickness between the two parallel major surfaces. The 3D object defines holes in a first major surface of two parallel major surfaces and cavities in the airlaid blank.

[0012] The present invention relates to airlaid blanks that can be produced into highly cushioned 3D shaped products suitable for packaging goods, thereby providing excellent shock absorption and damping properties. The 3D shaped products also have thermal insulation properties, so they can be used to store and / or transport temperature-regulated (e.g., cold or hot) goods, such as provisions and foodstuffs. The 3D shaped products suitable for cushioning and / or thermal protection are additionally made of environmentally friendly natural fibers, in stark contrast to prior art foam inserts made of polystyrene and other polymers. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The embodiments together with further objects and advantages thereof may best be understood by reference to the following description taken in conjunction with the accompanying drawings, in which:

[0014] Figure 1 is a cross-sectional view of an airlaid blank according to one embodiment;

[0015] Figure 2 is a cross-sectional view of an airlaid blank according to another embodiment;

[0016] Figure 3 is a cross-sectional view of an airlaid blank according to another embodiment;

[0017] Figure 4 is a flow chart illustrating a method of producing an airlaid blank according to one embodiment;

[0018] Figure 5 It shows Figure 4 a flow chart of additional optional steps of the displayed method;

[0019] Figure 6 It shows Figure 4 or a flowchart of additional optional steps of the method shown in 13;

[0020] Figure 7 is a schematic diagram of an apparatus for producing airlaid blanks according to one embodiment;

[0021] Figure 8 Schematic diagram showing hot pressing of the male tool to Figure 1 In the airlaid blank shown;

[0022] Figure 9 yes Figure 8 A cross-sectional view of a 3D formed product formed by hot pressing;

[0023] Figure 10 Schematic diagram showing hot pressing of the male tool to Figure 2 In the airlaid blank shown;

[0024] Figure 11 yes Figure 10 A cross-sectional view of a 3D formed product formed by hot pressing;

[0025] Figure 12 is a flow chart illustrating a method of producing a 3D formed product according to one embodiment;

[0026] Figure 13 is a flow chart illustrating a method of producing an airlaid blank according to another embodiment;

[0027] Figure 14 It shows Figure 13 a flow chart of additional optional steps of the displayed method;

[0028] Figure 15 It shows Figure 13a flow chart of additional optional steps of the displayed method;

[0029] Figure 16 is a schematic diagram of an apparatus for producing an airlaid blank according to another embodiment; and

[0030] Figure 17 During operation Figure 16 Schematic diagram of an apparatus for producing air-laid blanks.

[0031] Figure 18 is a schematic diagram of an apparatus for producing airlaid blanks according to another embodiment. DETAILED DESCRIPTION

[0032] Embodiments of the present invention generally relate to airlaid blanks and methods of producing such airlaid blanks and three-dimensional (3D) formed products.

[0033] The 3D shaped products produced from air-laid blanks of embodiments of the present invention can be used as more environmentally friendly alternatives to corresponding 3D shaped products made from or derived from foamed polymers, such as expanded polystyrene (EPS). More sustainable alternatives to polymer products have been proposed in U.S. Patent Application No. 2010 / 0190020 and European Patent No. 1 446 286, both of which involve hot pressing a porous fiber mat produced by a process known as air-laying into a 3D structure using a matching rigid mold or by film molding. However, the 3D shaped products produced in the above-mentioned documents are dense, have a thin cross-section, and therefore have limited shock absorption or damping capabilities and relatively poor thermal insulation.

[0034] The 3D formed product produced according to an embodiment of the present invention is formed by hot pressing an air-laid blank comprising natural fibers and a thermoplastic polymer binder. Air-laid blanks (sometimes also referred to as dry-laid blanks, air-laid pads, dry-laid pads, air-laid webs or dry-laid webs) are formed by a process called air-laying, in which natural fibers and thermoplastic polymer binders are mixed with air to form a porous fiber mixture that is deposited on a carrier and consolidated or bonded by heating or thermoforming. The air-laid blank is characterized in that it is porous, has the characteristics of open-cell foam, and is produced with a so-called dry forming method, i.e., water is not usually added. The air-laid process was initially described in U.S. Patent No. 3,575,749. The air-laid blank can be a form as produced in the air-laid process. Alternatively, the air-laid blank can be a form that is at least partially processed, such as by being cut into a given form before hot pressing.

[0035] In stark contrast to U.S. Patent Application No. 2010 / 0190020 and European Patent No. 1 446 286, the 3D-formed products of embodiments of the present invention formed from airlaid blanks retain the characteristics of the airlaid blanks even after heat pressing and therefore have excellent shock-absorbing and thermal insulation properties. Consequently, 3D products can be produced with geometric shapes, i.e., 3D shapes, suitable for protecting goods during transport and / or storage. For example, the 3D-formed products may contain cavities designed to match the shape of the goods to be protected. Maintaining the porous characteristics of the airlaid blank starting material means that 3D-formed products can be used not only to protect consumer goods and products, but also to protect heavy equipment from impact. Furthermore, 3D-formed products produced according to embodiments of the present invention have improved thermal insulation properties compared to compact and dense 3D-formed products with thin cross-sections. This means that 3D-formed products can also or alternatively be used to store and / or transport goods that need to be kept cool, such as cold supplies, or goods that need to be kept hot or warm, such as ready-to-eat meals.

[0036] One aspect of the present invention relates to an airlaid blank 10, see Figures 1 to 3 The airlaid blank 10 comprises natural fibers in a concentration of at least 70% by weight of the airlaid blank 10 and a thermoplastic polymer binder selected in a concentration range of 2.5 to 30% by weight of the airlaid blank 10. The airlaid blank 10 has an average density, but a portion 11 of the airlaid blank has a density that differs from the average density. The airlaid blank 10 has two parallel planar major surfaces 12, 14.

[0037] Conventionally, airlaid blanks 10 are produced to form a fairly uniform and homogeneous mixture of natural fibers and one or more thermoplastic polymer binders. Consequently, these prior art airlaid blanks 10 have a substantially uniform density throughout the airlaid blank 10, wherein the density depends on the natural fibers and the thermoplastic polymer binder and the process parameters used in the airlaying process. However, the airlaying process used to produce or manufacture the airlaid blanks 10 of embodiments of the present invention produces at least one portion 11 of the airlaid blank 10 having a density that is different from the density of the other components 15 of the airlaid blank 10 and the average density of the airlaid blank 10.

[0038] As used herein, the average or mean density of an airlaid blank 10 refers to the total mass of the airlaid blank 10 divided by the volume of the airlaid blank 10 - excluding any cavities 13 in the airlaid blank 10 formed during the airlaying process, as referred to herein. Figures 13 to 17As further described. Accordingly, the density of the portion 11 of the air-laid blank 10 represents the average or mean value density of the portion 11 of the air-laid blank 10. In one embodiment, the portion 11 of the air-laid blank 10 may have a substantially uniform density that is different from the average density of the air-laid blank 10. However, the embodiment is not limited thereto. Therefore, the portion 11 of the air-laid blank 10 does not necessarily have a uniform density, such as through the full thickness of the air-laid blank 10. For example, when traveling through the thickness of the air-laid blank 10 from the first major surface 14 to the second major surface 12 of the air-laid blank 10 (i.e., from one of the two parallel flat major surfaces 12, 14 to the other of the two parallel flat major surfaces), the density may increase or decrease. However, the average density of the portion 11 of the air-laid blank 10 is still different from the average density of the air-laid blank 10.

[0039] In one embodiment, the portion 11 of the airlaid blank 10 having a density different from the average density of the airlaid blank 10 has a density lower than the average density of the airlaid blank 10 .

[0040] In one embodiment, the density of the portion 11 of the airlaid blank 10 is equal to or less than 95% of the average density, preferably equal to or less than 90%, equal to or less than 85%, equal to or less than 80%, or equal to or less than 75% of the average density of the airlaid blank 10. In some applications, the density of the portion 11 of the airlaid blank 10 can be even lower, such as equal to or less than 70%, equal to or less than 65%, equal to or less than 60%, equal to or less than 55%, such as equal to or less than 50% of the average density of the airlaid blank 10.

[0041] In one embodiment, the average density of the air-laid blank 10 is selected to be in the range of 10 to 60 kg / m 3 In the range of 15 to 60 kg / m 3 and more preferably 15 to 50 kg / m 3 within the range.

[0042] In one embodiment, the portion 11 of the airlaid blank 10 has a relative humidity of 1 to 50 kg / m 3 In the range of 2.5 to 40 kg / m 3 and more preferably 2.5 to 30 kg / m 3 In the range of 2.5 to 25 kg / m 3 The density is selected within the interval of , preferably with the proviso that the density of portion 11 of the air-laid blank 10 is lower than the average density of the air-laid blank 10.

[0043] 3D formed product 20 (see Figure 9 and11 ) is formed from the airlaid blank 10 in a hot pressing process that involves placing a male mold tool 30 (see Figure 8 and 9 ) into the airlaid blank 10 or hot pressing the airlaid blank 10 between such a male tool 30 and a female tool (not shown). Hot pressing may additionally impart a 3D shape to the airlaid blank 10 and the resulting 3D shaped product 20 via any protrusions 31 extending from the male tool 30. This means that different parts of the airlaid blank 10 are typically hot pressed with different hardnesses, depending on whether the part is aligned with one or more protrusions 31 of the male tool 30. Hot pressing the male tool 30 into the airlaid blank 10 or hot pressing the airlaid blank 10 between the male tool 30 and the female tool will at least partially compact and thereby densify the material, i.e., result in an increase in density and thereby a decrease in the porosity and open-cell foam structure of the airlaid blank 10.

[0044] Hot pressing of the prior art airlaid blank 10 not only increases the average density of the 3D formed product 20 compared to the average density of the airlaid blank 10, but also significantly increases the density of those portions of the airlaid blank 10 that engage with one or more protrusions 31 in the male tool 30, thereby significantly reducing porosity and reducing the open-cell foam structure. Therefore, when the male tool 30 is pressed into the airlaid blank 10 or when the airlaid blank 10 is hot pressed between the male tool 30 and the female tool, at least some portions of the airlaid blank 10 will be pressed to become relatively hard. These hard pressed portions will thus be more compact than the rest of the airlaid blank 10 and, therefore, less porous than other portions and have less open-cell foam structure in the resulting 3D formed product 20. Consequently, the hard pressed portions in the resulting 3D formed product 20 will have reduced shock absorption or damping capacity and relatively poor thermal insulation compared to the less-pressed portions of the resulting 3D formed product 20.

[0045] Embodiments of the present invention address the aforementioned disadvantages by preferably providing at least a portion 11 of the airlaid blank 10 with a density that is lower than the average density of the airlaid blank 10. This portion 11 of the airlaid blank 10 maintains at least a portion of the porosity of the airlaid blank 10 in the 3D shaped product 20 even when hot pressed harder than other portions 15 of the airlaid blank 10. Thus, the portion 11 of the airlaid blank 10 that is pressed harder than other portions of the airlaid blank 10 during hot pressing (e.g., aligned with one or more protrusions 31 of the male die tool 30) preferably has a density that is lower than the average density of the airlaid blank 10. This means that the density, and thus the porosity, in different portions of the resulting 3D shaped product 20 will be more similar than if an airlaid blank 10 having uniform density and porosity had been hot pressed.

[0046] Figure 1 Schematically shown is a cross-sectional view of an airlaid blank 10 positioned on a base plate 40. In the illustrated embodiment, individual portions 11 of the airlaid blank 10 have a lower density than the average density of the airlaid blank 10 and other portions 15 of the airlaid blank 10. Figure 8 The airlaid blank 10 is shown in connection with the heat pressing of a male die tool 30 comprising a single protrusion 31 substantially aligned with the low density portion 11 of the airlaid blank 10. The protrusion 31 preferably has a cross-sectional shape substantially corresponding to the cross-sectional shape of the low density portion 11. Figure 9 The resulting 3D shaped product 20 formed in a hot press is shown. The 3D shaped product 20 includes cavities 22 formed by protrusions 31 pressed into the low density portion 11 of the airlaid blank 10. Even though the low density portion 11 is hot pressed to be harder than the other portions 15 of the airlaid blank 10, the density and porosity of the corresponding portions 21 of the 3D shaped product 20 adjacent to the cavities 22 are more similar to the density and porosity of the other portions 25 of the 3D shaped product 20 that were not engaged with the protrusions 31 of the male mold tool 30 and thus were not hot pressed to be equally hard.

[0047] Therefore, although the low density portion 11 of the air-laid blank 10 has been heat pressed to be harder than the other portions 15 of the air-laid blank 10, the corresponding portion 21 in the 3D formed product preferably has a density similar to or slightly higher than the density of the other portions 25 of the 3D formed product 20.

[0048] In prior art airlaid blanks 10 having uniform density, the density of the hard pressed portions of the 3D shaped product can be 10 to 50 times higher than other portions of the 3D shaped product that are not equally hard pressed.

[0049] In one embodiment, the density of the hard pressed portion 21 in the 3D formed product 20 is equal to or less than 5 times the average density of the 3D formed product 20, preferably equal to or less than 4 times, such as equal to or less than 3 times or equal to or less than twice the average density of the 3D formed product 20. For example, the density of the hard pressed portion 21 in the 3D formed product may be equal to or less than 190%, equal to or less than 180%, equal to or less than 170%, equal to or less than 160%, equal to or less than 150%, equal to or less than 140%, equal to or less than 130%, equal to or less than 120%, or even equal to or less than 110% of the average density of the 3D formed product 20. In a specific embodiment, the 3D formed product 20 has a substantially uniform density.

[0050] exist Figure 1 , a single portion 11 having a density different from (preferably lower than) the average density of the air-laid blank 10 is shown. However, the embodiment is not limited thereto. The air-laid blank 10 may include a plurality (i.e., at least two) portions 11 having a density different from (preferably lower than) the average density of the air-laid blank 10. In this case, all of these plurality of portions 11 may have the same density, or they may have different densities. Figure 2 An example of the latter case is shown. In this example, the airlaid blank 10 comprises a first portion 11A having a first density and a second portion 11B having a second, different density. Furthermore, both the first and second densities are different (preferably less) than the average density of the airlaid blank 10 and, thus, the remainder 15 of the airlaid blank 10. Figure 10 and 11 The male tool 30 is shown as well as Figure 2 1. Heat pressing of an airlaid blank 10 is shown. In this example, the male die tool 30 includes a protrusion 31 having a main portion 31A aligned with the first portion 11A of the airlaid blank 10 and an outer or peripheral portion 31B aligned with the second portion 11B of the airlaid blank 10. The peripheral protrusion 31B extends further toward the airlaid blank 10 than the main protrusion 31A. This means that during heat pressing, the second portion 11B of the airlaid blank 10 will be heat pressed harder than the first portion 11A of the airlaid blank 10, which in turn will be heat pressed harder than the remainder 15 of the airlaid blank 10. Therefore, in a preferred embodiment of this example, the density of the second portion 11B is lower than the density of the first portion 11A, which in turn will be lower than the average density of the airlaid blank 10 and the density of the remainder 15 of the airlaid blank 10.

[0051] Figure 11 Shown in Figure 10A cross-sectional view of a 3D shaped product 20 formed in a hot press is shown. The 3D shaped product 20 includes a cavity 22 formed by the shape of the male mold tool 30, and in particular, by the shape of the protrusion 31. Although the portions 21A, 21B of the 3D shaped product 20 aligned with the cavity 22 have been hot pressed to be harder than other portions 25 of the 3D shaped product 20, the density and, therefore, the porosity of these portions 21A, 21B preferably remain within an acceptable range that provides them with shock absorbing or damping capabilities and / or good thermal insulation.

[0052] The density of the portion 11 of the airlaid blank 10 is different from (e.g., lower than) the average density of the airlaid blank before the airlaid blank 10 is exposed to any compression. Thus, the airlaid blank 10 includes portions 11, 15 having different densities before the airlaid blank 10 or any portion thereof is compressed. Compressing the airlaid blank 10 as referred to herein encompasses any cold or hot compression, calendaring, or pressing operation conventionally used to compact the airlaid blank 10.

[0053] In one embodiment, at least a portion 11 of the airlaid blank 10 having a density different from (preferably lower than) the average density of the airlaid blank 10 has a two-dimensional (2D) extension parallel to the two parallel planar major surfaces 12, 14 of the airlaid blank 10 and extends through the full thickness of the airlaid blank 10, such as Figure 1 and 2 is shown in .

[0054] For example, the at least one portion 11 may have any geometric 2D extension parallel to the major surfaces 12, 14, including but not limited to circular, oval, square, rectangular, triangular, polygonal, or even more irregular shapes. In one embodiment, the at least one portion 11 extends through the full thickness of the airlaid blank 10. In this case, the walls of the at least one portion 11 extending through the thickness of the airlaid blank 10 may be straight, i.e., perpendicular to the major surfaces 12, 14. In this case, depending on the cross-sectional shape of the at least one portion 11, the at least one portion 11 may, for example, be in the form of a prism or a right circular cylinder.

[0055] However, embodiments are not limited to having straight vertical walls and also encompass portions 11 having one or more inclined, concave, convex and / or parabolic walls.

[0056] exist Figure 1 and 2 In the embodiment shown, the portion 11 having a density different from (preferably lower than) the average density of the air-laid blank 10 extends through the full thickness of the air-laid blank 10. However, the embodiment is not limited thereto. Thus, the portion 11 may constitute only a portion of the thickness of the air-laid blank 10. Figure 3A cross-sectional view of an airlaid blank 10 according to such an example is shown. In this embodiment, the airlaid blank 10 comprises cavities 13 that extend into, but not through, the full thickness of the airlaid blank 10. In such an embodiment, portions 11 of the airlaid blank 10 having a density different from (preferably lower than) the average density of the airlaid blank 10 are then Figure 3 The cavity 13 shown is aligned. Thus, portion 11 is formed on top of cavity 13 (e.g. Figure 3 center) or below.

[0057] The two major surfaces 12, 14 of the air-laid blank 10 are substantially flat surfaces, as shown in Figures 1 and 2. In addition, the two major surfaces 12, 14 are parallel. Therefore, the air-laid blank 10 preferably has a uniform thickness.

[0058] In one embodiment, the thickness of the airlaid blank 10 is at least 20 mm, preferably at least 30 mm and more preferably at least 40 mm, or even thicker, such as at least 50 mm, at least 60 mm, at least 70 mm, at least 80 mm or at least 90 mm. In a specific embodiment, the thickness of the airlaid blank 10 is at least 100 mm, such as at least 150 mm, at least 200 mm, or at least 250 mm. It is also possible to have very thick airlaid blanks 10 with a thickness of at least 300 mm.

[0059] In one embodiment, natural fiber is wood fiber. In a specific embodiment, natural fiber is 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 a form selected from the group consisting of sulfate pulp, sulfite pulp, thermomechanical pulp (TMP), high temperature thermomechanical pulp (HTMP), mechanical fibers (MDF-fibers) intended for medium density fiberboard, chemical-thermomechanical pulp (CTMP), high temperature chemical-thermomechanical pulp (HTCTMP), and combinations thereof.

[0060] Natural fibers can 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 hulls.

[0061] The airlaid blank 10 comprises natural fibers in a concentration of at least 70% by weight of the airlaid blank 10. 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.

[0062] Thermoplastic polymer binder is included in the airlaid blank 10 as an adhesive so that the airlaid blank 10 is bonded together and maintains its form and structure during use, handling and storage. Thermoplastic polymer binder can also help to build the foam-like structure of the airlaid blank 10. The thermoplastic polymer binder is entangled with the natural fibers to form a fiber mixture during the airlaid process. Thermoplastic polymer binder can be added in powder form, but is more usually added in the form of fibers that are entangled with the natural fibers in the airlaid process. Alternatively or in addition, the thermoplastic polymer binder can be added into and onto the airlaid blank 10 as a solution, emulsion or dispersion during the airlaid process.

[0063] In a particular embodiment, the thermoplastic polymer binder is selected from the group consisting of thermoplastic polymer powders, thermoplastic polymer fibers, and combinations thereof.

[0064] In one embodiment, the thermoplastic polymer binder, or at least a portion thereof, has a softening point that does not exceed the degradation temperature of the natural fibers. Thus, the thermoplastic polymer binder softens at processing temperatures that do not exceed the degradation temperature of the natural fibers during heating and hot pressing. This means that the thermoplastic polymer binder becomes ductile and maintains at least a portion of the porous structure of the 3D formed product 20 at temperatures that do not degrade the natural fibers in the airlaid blank 10.

[0065] In one embodiment, the thermoplastic polymer binder is made of: 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), copolymers thereof and mixtures thereof, and ii) optionally one or more additives.

[0066] Thus, in one embodiment, the thermoplastic polymer binder is made of a material selected from the group mentioned above.In another embodiment, the thermoplastic polymer fiber is made of a material selected from the group mentioned above and one or more additives.

[0067] In one embodiment, the thermoplastic polymer binder is or comprises thermoplastic polymer fibers cut into fixed lengths, which are typically referred to as staple fibers. If the length of the thermoplastic polymer fibers is of the same order of magnitude as or longer than the length of the natural fibers, it is generally preferred for mixing in the air-laid process and thus for the properties of the air-laid blank 10 formed. The lengths of the thermoplastic polymer fibers and natural fibers as mentioned herein are length-weighted average fiber lengths. The length-weighted average fiber length is calculated as the sum of the squares of the individual fiber lengths divided by the sum of the individual fiber lengths.

[0068] In one embodiment, the thermoplastic polymer binder is or comprises thermoplastic polymer fibers having a length-weighted average fiber length selected from 100 to 600%, preferably 125 to 500%, and more preferably 150 to 450% of the length-weighted average fiber length of the natural fibers. In a specific embodiment, the thermoplastic polymer binder is or comprises thermoplastic polymer fibers having a length-weighted average fiber length selected from 200 to 400%, preferably 250 to 350% of the length-weighted average fiber length of the natural fibers. In a specific embodiment, the length-weighted average fiber length of the thermoplastic polymer fibers is in the range of 1 to 10 mm, preferably 2 to 8 mm, and more preferably 2 to 6 mm.

[0069] The length-weighted average fiber length of natural fibers depends on the source of the natural fibers (such as the tree species from which they are derived) and the pulping process. The length-weighted average fiber length of wood pulp fibers typically ranges from about 0.8 mm up to about 5 mm.

[0070] In one embodiment, the thermoplastic polymer binder is or comprises, such as consists of, monocomponent and / or bicomponent thermoplastic polymer fibers. Bicomponent thermoplastic polymer fibers (also known as bico fibers) comprise a core and sheath structure, wherein the core is made of a first polymer, copolymer, and / or polymer blend, and the sheath is made of a second, different polymer, copolymer, and / or polymer blend.

[0071] In one embodiment, the thermoplastic polymer binder is or comprises a monocomponent thermoplastic polymer fiber, such as consisting of a monocomponent thermoplastic polymer fiber, which is made of: i) a material selected from PE, EAA, EVA, PP, PS, PBAT, PBS, PLA, PET, PCL, copolymers thereof, and mixtures thereof, and ii) optionally one or more additives. In another embodiment, the thermoplastic polymer binder is or comprises a bicomponent thermoplastic polymer fiber, such as consisting of a bicomponent thermoplastic polymer fiber, which has a core and / or sheath made of: i) one or more materials selected from PE, EAA, EVA, PP, PS, PBAT, PBS, PLA, PET, PCL, copolymers thereof, and mixtures thereof, and ii) optionally one or more additives. In another embodiment, the thermoplastic polymer binder is or comprises, such as consists 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, copolymers thereof, and mixtures thereof, and ii) optionally one or more additives; and a bicomponent thermoplastic polymer fiber having a core and / or sheath made of: i) one or more materials selected from the group consisting of PE, EAA, EVA, PP, PS, PBAT, PBS, PLA, PET, PCL, copolymers thereof, and mixtures thereof, and ii) optionally one or more additives.

[0072] 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 or materials 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.

[0073] In one embodiment, the thermoplastic polymer binder is a thermoplastic polymer powder made from: i) a material selected from PE, EAA, EVA, PP, PS, PBAT, PBS, PLA, PET, PCL, copolymers thereof, and mixtures thereof, and ii) optionally one or more additives.

[0074] It is also possible to use a thermoplastic polymer binder that is a combination of thermoplastic polymer fibers and thermoplastic polymer powder.

[0075] In one embodiment, the airlaid blank 10 comprises a thermoplastic polymer binder in a concentration selected from the range of 10 to up to 30%, such as 12.5 to up to 30% or 15 to up to 30%, based on the weight of the airlaid blank 10. In a specific embodiment, the airlaid blank 10 comprises greater than 15 weight percent but not more than 30 weight percent of the thermoplastic polymer binder. For example, the airlaid blank 10 comprises a thermoplastic polymer binder in a concentration selected from the range of 15 or 17.5 to up to 30%, based on the weight of the airlaid blank 10. In a specific embodiment, the airlaid blank 10 comprises a thermoplastic polymer binder in a concentration selected from the range of 15 or 17.5 to up to 25%, such as 20 to up to 25%, based on the weight of the airlaid blank 10.

[0076] In some applications, it may be advantageous to have a relatively high concentration of thermoplastic polymer binder, such as greater than 15% by weight of the airlaid blank 10, in order to maintain the integrity and foam-like structure of the airlaid blank 10 even when the airlaid blank 10 is pressed at relatively low pressures to obtain the porous 3D shaped product 20. Therefore, if too low a concentration of thermoplastic polymer binder is included, i.e., less than 2.5% by weight of the airlaid blank 10, the formed 3D shaped product 20 may unintentionally disintegrate or break apart because the combination of too low a concentration of thermoplastic polymer binder and the "soft" hot pressing of the airlaid blank 10 is insufficient to maintain the structure of the 3D shaped product 20.

[0077] In some embodiments, the air-laid blank 10 contains a thermoplastic polymer binder selected in a concentration ranging from 2.5 to 15% by weight of the air-laid blank 10, preferably from 4 to 15% by weight of the air-laid blank 10, such as from 5 to 15% by weight of the air-laid blank 10, or from 7.5 to 15% by weight of the air-laid blank 10, and more preferably from 10 to 15% by weight of the air-laid blank 10.

[0078] In one embodiment, the 3D formed product 20 is configured to protect packaged goods from electrostatic discharge (ESD). In such an embodiment, the airlaid blank 10 is conductive or semiconductive. For example, the airlaid blank 10 may contain a conductive polymer or conductive fibers to make the airlaid blank 10, and thus the 3D formed product 20 formed by heat pressing the airlaid blank 10, conductive or semiconductive. In this case, the airlaid blank 10 preferably contains a conductive polymer or fiber at a concentration of no more than 10% by weight of the airlaid blank 10, and more preferably no more than 5% by weight of the airlaid blank 10. In one embodiment, a portion of the natural fibers may be replaced with a conductive polymer or fiber. In another embodiment, the thermoplastic polymer binder is made of or contains a conductive polymer. In another embodiment, these two embodiments are combined. In a specific embodiment, the conductive polymer or fiber is carbon fiber. Instead of or in addition to having a conductive polymer or fiber, the airlaid blank 10 may contain a conductive or semiconductive filler, such as carbon black, which may be in the form of an additive to the binder.

[0079] Thus, in addition to the natural fibers and the thermoplastic polymer binder, the airlaid blank 10 may also contain one or more additives. The one or more additives may be added to the thermoplastic polymer binder and / or added when the thermoplastic polymer binder is produced. Alternatively or additionally, the one or more additives may be added to the natural fibers. Alternatively or additionally, the one or more additives may be added to the natural fibers and the thermoplastic polymer binder, such as during the airlaying 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 some applications, it may be desirable to seal some or all of the surfaces of the 3D formed product 20, such as by heating, to prevent linting from one or more surfaces onto the packaged goods. The surfaces heat-treated in the hot press will be sealed, and no additional (heat) sealing is required. At least one surface to be sealed can be sealed, such as by heating, before or after the hot pressing operation. Therefore, in one embodiment, the 3D formed product 20 comprises at least one surface that is heat-sealed to suppress linting on at least one surface. For example, the end surfaces of the 3D formed product 20 may not be processed by the airlaid blank 10, or may be produced by sawing, cutting or punching the airlaid blank 10 to produce these end surfaces. In this case, it may be preferred to heat-seal these surfaces to prevent or at least suppress or inhibit linting. Any surface exposed to heat during the hot pressing generally does not require any heat sealing.

[0082] In some applications, the 3D formed product 20 or at least a portion thereof can be laminated with a surface layer such as a thermoplastic polymer film or a nonwoven textile. This can prevent linting and can also add additional functions to the surface, such as moisture resistance, tactile properties, color, and design. The film or nonwoven material can be made of any common thermoplastic polymer. Examples include the thermoplastic polymer materials used as adhesives mentioned above. The layer can be heat laminated or extruded onto the air-laid blank 10 and / or directly laminated onto the 3D formed product 20. In one embodiment, the film laminated to at least one surface of the 3D formed product 20 or a portion thereof is conductive or semi-conductive to provide ESD protection for the packaged goods.

[0083] Thus, in one embodiment, the 3D shaped product 20 comprises at least one surface coated with a surface layer selected from the group consisting of a down suppressing layer, a moisture barrier layer, a tactile layer, and a coloring layer.

[0084] The film, textile or surface layer can be attached to the airlaid blank 10 or 3D shaped product 20 with the help of a thin layer of hot melt glue, through an additional adhesive film, or by itself becoming semi-molten and tacky during the hot lamination process. This operation can be performed before, after, or simultaneously with the hot pressing operation. If lamination is performed on at least one surface of the airlaid blank 10, which will subsequently be processed by hot pressing, the softening point of the surface laminate should not exceed the degradation temperature of the natural fibers of the airlaid blank 10.

[0085] In another embodiment, the surface layer can be applied by spraying it onto one or more surfaces of the 3D formed product 20 or airlaid blank 10. This layer can comprise any one or more substances that can be prepared as a solution, emulsion, or dispersion, such as thermoplastic polymers; natural polymers such as starch, agar, guar gum, or locust bean gum; microfibrillated or nanofibrillated cellulose or lignocellulose; or mixtures thereof. Furthermore, the surface layer can comprise other substances that provide additional functionality to the surface layer and the 3D formed product 20, such as emulsifiers, stabilizers, conductive agents, and the like.

[0086] Another aspect of the present invention relates to a method of producing an airlaid blank 10, see Figure 4 and an embodiment showing an apparatus 100 for producing an airlaid blank 10 Figure 7. The method includes introducing natural fibers and a thermoplastic polymer binder and / or a mixture of natural fibers and a thermoplastic polymer binder into an upper end 112 of a forming head 110 in step S1. The method also includes conveying the natural fibers and the thermoplastic polymer binder and / or the mixture to a lower end 114 of the forming head 110 by a vacuum applied to an air-permeable collector 120 in step S2, the air-permeable collector being arranged to be connected to the lower end 114 of the forming head 110. The method also includes capturing the natural fibers and the thermoplastic polymer binder and / or the mixture on the air-permeable collector 120 in step S3. The method additionally includes heating the natural fibers and the thermoplastic polymer binder and / or the mixture to form the air-laid blank 10 in step S4.

[0087] According to this aspect, the airlaid blank 10 comprises natural fibers at a concentration of at least 70% by weight of the airlaid blank 10 and a thermoplastic polymer binder at a concentration selected from the range of 2.5 up to 30% by weight of the airlaid blank 10.

[0088] The permeable collector 120 has an average air permeability. In one embodiment, the air permeability of a portion 121 of the permeable collector 120 is different from the average air permeability. Alternatively or in addition, an object 125 is positioned on the portion 121 of the permeable collector 120. In this case, the air permeability of the portion 121 of the permeable collector 120 on which the object 125 is positioned is different from the average air permeability. According to the present invention, the airlaid blank 10 has an average density, and the density of the portion 11 of the airlaid blank 10 aligned with the portion 121 of the permeable collector 120 is different from the average density. The airlaid blank 10 has two parallel flat major surfaces 12, 14.

[0089] The equipment 100 for producing air-laid blank 10 comprises forming head 110, also referred to as forming chamber in the art. Natural fiber and thermoplastic polymer binder are input into forming head 110 as one or more discrete input streams and / or as one or more mixed input streams. For example, forming head 110 can comprise a stream input of natural fiber and a stream input of thermoplastic polymer binder at its upper end 112. In another embodiment, forming head 110 comprises a plurality of stream inputs of natural fiber and a stream input of thermoplastic polymer binder, a stream input of natural fiber and a plurality of stream inputs of thermoplastic polymer binder, or a plurality of stream inputs of natural fiber and a plurality of stream inputs of thermoplastic polymer binder. In these illustrative examples, natural fiber and thermoplastic polymer binder are mixed and blended during conveying through forming head 110, and the mixture of final natural fiber and thermoplastic polymer binder is deposited on air permeability collector 120.

[0090] Alternatively or in addition, one or more input streams of natural fibers and / or one or more input streams of thermoplastic polymer binder, a preformed mixture between natural fibers and thermoplastic polymer binder, can be introduced into the forming head 110 at one or more stream inputs.

[0091] In step S2, the natural fibers and thermoplastic polymer binder and / or a mixture thereof are conveyed from the upper end 112 to the lower end 114 through the forming head 110 by a vacuum (i.e., suction) applied to the permeable collector 120 or under pressure, which is arranged to be connected to the lower end 114 of the forming head 110.

[0092] Thus, the vacuum applied to the permeable collector 120 draws the natural fibers and thermoplastic polymer binder and / or mixture thereof toward the lower end 114 of the forming head 110 and down onto the permeable collector 120. The vacuum may also aid in mixing the natural fibers and thermoplastic polymer binder during transport through the forming head 110 and in compacting the fiber mixture onto the permeable collector 120.

[0093] The collector 120 is air permeable to allow a vacuum to be applied thereto and to draw the natural fibers and thermoplastic polymer binder onto the 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. However, any such openings are preferably small enough to prevent the natural fibers and thermoplastic polymer binder from passing through the air permeable collector 120. Thus, the natural fibers and thermoplastic polymer binder are instead deposited onto the air permeable collector 120 as a fiber mixture.

[0094] The applied vacuum compacts the natural fibers and thermoplastic polymer binder on the permeable collector 120. The density, and thus the porosity, of at least the portion 11 of the resulting air-laid blank 10 is controlled or varied by causing the air permeability of the portion 121 of the permeable collector 120 to differ from the average air permeability of the collector 120 and / or by positioning an object 125 on the portion 121 of the permeable collector 120 such that the air permeability of the portion 121 on which the object 125 is positioned differs from the average air permeability of the permeable collector 120.

[0095] The portion 121 of the permeable collector 120 and / or the object 125 positioned on the portion 121 of the permeable collector 120 thereby locally affects the vacuum and the air draw through the permeable collector 120 such that the vacuum and the air draw at that portion 121 of the permeable collector 120 will be different compared to the vacuum and the air draw at other portions of the permeable collector 120. Such localized changes in vacuum and air draw are possible because the permeability of the portion 121 of the permeable collector 120 and / or the portion 121 having the object 125 is different from the average permeability of the permeable collector 120.

[0096] In one specific embodiment, the air permeability of the portion 121 of the permeable collector 120 and / or the portion 121 with the object 125 is lower than the average air permeability of the permeable collector 120. As a result, a lower vacuum and air extraction are applied to the natural fibers and thermoplastic polymer binder, and thus to the portion 11 of the airlaid blank 10 aligned with the portion 121 of the permeable collector 120 and / or the object 125. The lower vacuum and air extraction, in turn, result in less compaction of the natural fibers and thermoplastic polymer binder in the portion 11 of the airlaid blank 10. As a result, the density of the portion 11 of the airlaid blank 10 is different from (preferably lower than) the average density of the airlaid blank 10.

[0097] The permeable collector 120 may include one or more portions 121 having a different permeability than other portions of the permeable collector 120. In another embodiment, at least one object 125 is positioned on the permeable collector 120, such as Figure 7 In such an embodiment, the method comprises Figure 5 An additional step S10 is shown. This step S10 therefore comprises positioning the object 125 onto the permeable collector 120 .

[0098] Object 125 can be any object that, when positioned on portion 121 of permeable collector 120, adjusts or changes the air permeability of portion 121 of permeable collector 120. A typical example of an object 125 that can be used in accordance with embodiments is a porous object 125 having multiple channels or passages extending through the thickness of object 125 and allowing air to pass through these channels or passages. Object 125 can have a uniform air permeability, or different portions of object 125 can have different air permeabilities. For example, the porosity of object 125 can vary in different portions of object 125. In a specific embodiment, the air permeability of object 125 is different from the average air permeability of permeable collector 120.

[0099] Another example of an object 125 that can be used in accordance with an embodiment is a substantially impermeable, non-porous object 125. Such an impermeable object 125 is particularly suitable for producing an airlaid blank 10 having a low-density portion 11. It is also possible to have an object 125 that includes at least one permeable portion and at least one impermeable portion.

[0100] Object 125 may be made of a variety of materials including, but not limited to, plastics, polymers, metals, including metal alloys, and the like.

[0101] When positioned in a plane parallel to the permeable collector 120 , the shape or form of the object 125 in that plane defines the shape or form of a portion 11 of the airlaid blank 10 having a density different from the average density of the airlaid blank 10 .

[0102] The permeable collector 120 can be a plate, tray, or similar planar collector 120 that is arranged to be connected to the lower end 114 of the forming head 110. Once the airlaid blank 10 has been formed on the permeable collector 120, the collector 120 with the airlaid blank 10 positioned thereon can be removed from the forming head 110.

[0103] In another embodiment capable of continuously producing the airlaid blank 10, the air permeable collector 120 may be a Figure 7 The form of the air permeable belt collector 120 shown is run between drive rollers 122, 124. In this case, Figure 5 In step S10 , the object 125 (if used) may be positioned on the air permeable belt collector 120 at a location upstream of the forming head 110 .

[0104] Upstream refers to the direction of movement of the permeable belt collector 120 from the drive roller 122 to the drive roller 124. Thus, at this upstream position, at least one object 125 can be placed onto the permeable belt collector 120 and thereby conveyed into the forming head 110 by the action of the drive rollers 122, 124, thereby allowing the mixture of natural fibers and thermoplastic polymer binder to be deposited onto the permeable belt collector 120 and the object 125 while a vacuum is applied to the permeable belt collector 120. The permeable belt collector 120 moves with the object 125 and the mixture of natural fibers and thermoplastic polymer binder thereon to be output from the forming head 110.

[0105] The natural fibers and thermoplastic polymer binder and / or mixture thereof are heated to form the airlaid blank 10. This heating step may be performed in an oven ( Figure 7The natural fibers and the thermoplastic polymer binder are preferably heated to a temperature at which the thermoplastic polymer binder is in a ductile state or a molten state, preferably a ductile but not molten state. For most thermoplastic polymer binders, this temperature is in the range of 80° C. to 180° C., such as 100° C. to 180° C. or 120° C. to 160° C. Thus, in one embodiment, as Figure 4 The heating applied in step S4 preferably reaches a temperature in the interval 80°C up to 180°C.

[0106] Another aspect of the embodiment relates to a method of producing a 3D formed product 20, see Figures 8 to 12 The method involves Figure 12 In step S20, a male mold tool 30 is hot-pressed into the airlaid blank 10 to form a 3D shaped product 20 having a 3D shape at least partially defined by the male mold tool 30. The airlaid blank 10 contains natural fibers in a concentration of at least 70% by weight of the airlaid blank 10 and a thermoplastic polymer binder in a concentration selected within the range of 2.5 to 30% by weight of the airlaid blank 10. The airlaid blank 10 has an average density, and the density of the portion 11 of the airlaid blank 10 is different from the average density. The male mold tool 30 used in the hot pressing in step S20 includes a protrusion 31 that is configured to be pressed into the airlaid blank 10, as shown in FIG. Figure 8 and 10 The protrusions 31 are then configured to align with portions 11; 11A, 11B of the airlaid blank 10 having a density different from the average density of the airlaid blank 10 during heat pressing.

[0107] As used herein, hot pressing refers to exposing the airlaid blank 10 to pressure applied by pressing a male tool 30 or a male tool 30 and a female tool (not shown) into the airlaid blank 10 while heating or exposing the airlaid blank 10 to heat. Thus, hot pressing means that the pressing is performed at a temperature above room temperature, preferably at a temperature at which the thermoplastic polymer binder is ductile.

[0108] In one embodiment, Figure 12Step S20 in the embodiment includes hot pressing a heated male mold tool 30 into the airlaid blank 10. In this embodiment, the heated male mold tool 30 is preferably heated to a temperature selected in the range of 120° C. to 210° C., preferably in the range of 120° C. to 190° C. The male mold tool 30 may include heating elements, which are preferably controllable heating elements to heat the male mold tool 30 to the desired hot pressing temperature. The temperature of the male mold tool 30 typically depends on the type of natural fibers and thermoplastic polymer binder in the airlaid blank 10 and the hot pressing cycle time in step S20. However, the ranges presented above are suitable for most combinations of natural fibers, thermoplastic polymer binders and cycle times.

[0109] In one embodiment, the airlaid blank 10 is positioned on a base plate 40, such as Figures 8 to 11 In one embodiment, Figure 12 Step S20 in the embodiment includes hot pressing a heated male mold tool 30 into the airlaid blank 10 positioned on a base press plate 40 having a temperature equal to or lower than ambient temperature.

[0110] In these embodiments, heating of the airlaid blank 10 is achieved by the male mold tool 30, while the base platen 40 is at ambient temperature, typically room temperature, or can even be cooled. Having the base platen 40 at ambient temperature or even cooled can reduce the risk of heating the airlaid blank 10 too much during the hot pressing in step S20, which could otherwise have the negative consequences of degrading the natural fibers, the melted thermoplastic polymer binder, and destroying the porous structure of the airlaid blank 10 and the formed 3D shaped product 20.

[0111] However, during the hot pressing in step S20, the airlaid blank 10 can be positioned on the heated base platen 40 even in combination with the heated male mold tool 30. In this case, the lower side of the airlaid blank 10 facing the heated base platen 40 will also be heat sealed during the hot pressing.

[0112] In another embodiment, Figure 12 Step S20 in the embodiment includes hot pressing a male mold tool 30 and a female mold tool into the airlaid blank 10 positioned between the male mold tool 30 and the female mold tool to form a 3D shaped product 20 having a 3D shape at least partially defined by the male mold tool 30 and the female mold tool. In this embodiment, the male mold tool 30 forms a 3D shaped cavity 22 in the formed 3D shaped product 20, while the female mold tool contains a 3D shaped cavity that defines the outer geometry and 3D shape of the 3D shaped product 20.

[0113] In one embodiment, both the male tool 30 and the female tool are heated to a temperature preferably selected in the range of 120° C. to 210° C., preferably in the range of 120° C. to 190° C. The male tool 30 and the female tool may be heated to the same temperature or to different temperatures. In another embodiment, one of the male tool 30 and the female tool is heated while the other is at ambient temperature.

[0114] In the embodiment presented above, at least one of the tools used in the hot pressing in step S20 is heated. In another embodiment, Figure 12 In step S20 of the method, at least a portion of the airlaid blank 10 is heated before the male mold tool 30 is hot pressed into the airlaid blank 10.

[0115] Therefore, the airlaid blank 10 is heated, rather than the male tool 30 and / or any female tool, preferably before the hot pressing operation. The airlaid blank 10 is then preferably heated to a temperature at which the thermoplastic polymer binder is in a ductile but unmolten state. For most thermoplastic polymer binders, this temperature is in the range of 80°C to 180°C, such as 100°C to 180°C or 120°C to 160°C. Therefore, in one embodiment, the airlaid blank 10 is preferably heated to a temperature in the range of 80°C to 180°C.

[0116] In this embodiment, the male tool 30 and the base platen 40 or female tool may independently be at ambient temperature (eg, room temperature) or cooled.

[0117] Alternatively, heating of the airlaid blank 10 may be combined with the use of a heated male tool 30 or a heated male tool 30 and / or a heated female tool.

[0118] In one embodiment, Figure 12 Step S20 in includes hot pressing the male tool 30 into the airlaid blank 10 by hot pressing a portion 11 of the airlaid blank 10 to be harder than the other portion 15 of the airlaid blank 10 to which the male tool 30 is engaged.

[0119] Therefore, during hot pressing, a portion 11 of the airlaid blank 10 having a density, and thus a porosity, different from (preferably lower than) the average density and porosity of the airlaid blank 10 is pressed correspondingly harder by being aligned with the protrusions 31 via the male mold tool 30. However, although this portion 11 is hot pressed harder than the other portions 15, this portion 21; 21A, 21B in the resulting 3D shaped product 20 still has a porosity sufficient to be suitable for shock absorption and damping and / or thermal insulation.

[0120] In one embodiment, Figure 12 The air-laid blank 10 hot-pressed in step S20 has two parallel flat major surfaces 12, 14.

[0121] Another embodiment of a method of producing an airlaid blank 10 is schematically shown in Figure 13 See also the flowchart of Figure 16 and 17 The method includes introducing natural fibers and a thermoplastic polymer binder and / or a mixture of natural fibers and a thermoplastic polymer binder into the upper end 112 of the forming head 110 in step S30. This step corresponds to Figure 4 and is not further described herein.

[0122] In the next step S31, the natural fibers and the thermoplastic polymer binder and / or the mixture thereof are fed to the lower end 114 of the forming head 110, which is arranged to be connected to a belt collector 120 running between drive rollers 122, 124. The method further comprises positioning the 3D object 127 on the belt collector 120 in step S32 and capturing the natural fibers and the thermoplastic polymer binder and / or the mixture thereof on the belt collector 120 in step S33. The method further comprises heating the natural fibers and the thermoplastic polymer binder and / or the mixture thereof in step S34 to form the airlaid blank 10. This step S34 corresponds to Figure 4 and is not further described herein.

[0123] According to the present invention, the airlaid blank 10 comprises natural fibers in a concentration of at least 70% by weight of the airlaid blank 10 and a thermoplastic polymer binder in a concentration selected from the range of 2.5 up to 30% by weight of the airlaid blank 10. The resulting airlaid blank 10 has two parallel major surfaces 12, 14 (see Figure 3 ) and a thickness between the two parallel major surfaces 12, 14. The 3D object 127 defines holes 17 in the first major surface 14 of the two parallel major surfaces 12, 14 and cavities 13 in the airlaid blank 10.

[0124] In one embodiment, the two parallel major surfaces 12 , 14 are two parallel planar major surfaces 12 , 14 .

[0125] According to Figure 13 The airlaid blank 10 produced by the method shown in the flow chart of FIG. 1 comprises at least one cavity 13 having holes 17 and formed and generated by the presence of 3D objects 127 on the belt collector 120. Thus, the 3D objects 127 locally block the natural fiber and thermoplastic polymer binder mixture from being present in the portion of the airlaid blank 10 occupied by the 3D objects 127.

[0126] The 3D objects 127 can thus be used to form cavities 13 in the airlaid blank 10. For example, such cavities 13 can be defined to match the article to be protected by the 3D shaped product 20. Thus, a 3D object 127 having a selected shape can be used to create cavities 13 in the airlaid blank 10 and thus in the 3D shaped product 20 produced from the airlaid blank 10. Figure 13 The method shown thus enables the production of an airlaid blank 10 having cavities 13 shaped and thus adapted to the goods and articles to be protected from shocks and / or heat.

[0127] The cavities 13 comprise holes or openings 17 in the first major surface 14 of the airlaid blank 10. The cavities 13 preferably extend a portion of the thickness of the airlaid blank 10 from the first major surface 14 to the second major surface 12. In such embodiments, the cavities 13 thus do not extend through the full thickness of the airlaid blank 10. In other embodiments, the cavities 13 may actually comprise first holes 17 in the first major surface 14 and second holes (not shown) in the second major surface 12, i.e., extend through the full thickness of the airlaid blank 10.

[0128] Generally speaking, compared to using a male die tool to heat press cavities into the airlaid blank 10, Figure 13 The method disclosed in the flow chart of FIG. 1 can produce more complex cavities 13 in the airlaid blank 10. This means that the cavities 13 in the airlaid blank 10 can have quite complex geometries and shapes that are well suited to the shape of any goods to be protected by the 3D formed product 20 produced in the hot press of the airlaid blank 10.

[0129] In one embodiment, the density of any portion 11 of the airlaid blank 10 that is aligned with the cavity 13 in the direction through the thickness of the airlaid blank 10 is different from the average density of the airlaid blank 10, such as Figure 3 In such an embodiment, the belt collector 120 is preferably an air-permeable belt collector 120 on which a vacuum is applied, as previously described herein. The 3D object 127 is preferably at least partially air-permeable.

[0130] As from Figure 17 The output of the airlaid blank 10 of the apparatus 100 may contain the 3D object 127. Thus, the 3D object 127 is then contained in the airlaid blank 10 and is thereby surrounded by the mixture of natural fibers and thermoplastic polymer binder. In such an embodiment, the method may include the following: Figure 14 The additional step S41 is shown. The method starts Figure 131. The process continues with step S34 in step S41. Step S41 includes removing the 3D object 127 from the airlaid blank 10. This step S41 can involve manually removing the 3D object 127 from the airlaid blank 10 as output from the apparatus 100. Alternatively, a robot or other machine can remove the 3D object 127 from the airlaid blank 10 to thereby obtain an airlaid blank 10 having cavities 13.

[0131] In one embodiment, the 3D object 127 comprises a tracking device 128. In such an embodiment, the method includes Figure 14 An additional step S40 is shown. This step S40 comprises identifying the 3D object 127 in the airlaid blank 10 based on the tracking device 128. The method then continues to step S41, where the identified 3D object 127 is removed from the airlaid blank 10.

[0132] Various types of tracking devices 128 can be used to identify the 3D object 127 in the airlaid blank 10. For example, the tracking device 128 may include a magnet, or be made of a magnetic material or include a magnetic material. In this case, the tracking device 128 and thus the 3D object 127 can be identified in the airlaid blank 10 using a magnet or a device that measures or responds to the magnetism of the magnet in the 3D object 127. Another solution is to have a tracking device 128 in the form of a radio frequency identification (RFID) tag, or a near field communication (NFC) device that can wirelessly communicate with an external detector or device used to identify the tracking device 128 and the 3D object 127 in the airlaid blank 10. Another alternative is to use an inductive sensor that can be used to detect metal objects. In this case, the 3D object 127 can be made of a metal material or at least include a metal material. The above embodiments of the tracking device 128 should only be regarded as illustrative but non-limiting examples of tracking devices 128 that can be used to identify 3D objects 127 in the airlaid blank 10.

[0133] 3D object 127 may be made of a variety of materials including, but not limited to, plastics, polymers, metals, including metal alloys, and the like.

[0134] Figure 15 It shows Figure 13 Flow chart of the embodiment of step S32 in the method. Figure 13 The process continues with step S31 in step S50. The next step S50 includes introducing the 3D object 127 into the airlock 135 of the positioning head or chamber 130, which is arranged upstream of the forming head 110 but connected to the forming head 110 at least through the delivery opening 132. This embodiment also includes positioning the 3D object 127 on the tape collector 120 within the positioning head 130 in step S51.

[0135] Therefore, the 3D objects 127 are preferably positioned on the tape collector 120 upstream of the forming head 110 and within a positioning head 130, which is arranged upstream of the forming head 110 in the apparatus 100 but connected to the forming head 110 via a delivery opening 132. The delivery opening 132 thus enables the 3D objects 127 positioned on the tape collector 120 to be delivered from the positioning head 130 to the forming head 110.

[0136] In one embodiment, the belt collector 120 is a permeable belt collector 120 as previously described herein, with a vacuum applied to the permeable belt collector 120 to draw the natural fibers and thermoplastic polymer binder and / or mixture thereof from the upper end 112 of the forming head 110 to the lower end 114 and onto the permeable belt collector 120. In this case, the positioning head 130 preferably includes or is connected to an airlock 135 through which the 3D object 127 is introduced into the forming head 130. Without such an airlock 135 for introducing the 3D object 127 into the positioning head 130, the opening of any opening in the positioning head 130 would adversely affect the vacuum-driven transport of the natural fibers and thermoplastic polymer binder and / or mixture thereof through the forming head 110. The airlock 135 thus enables the introduction of the 3D object 127 into the positioning head 130 without any significant negative impact on the vacuum-driven transport of the natural fibers and thermoplastic polymer binder and / or mixture thereof through the forming head 110.

[0137] In one embodiment, Figure 4 The methods shown and / or Figure 13 The methods shown may include Figure 6 The resulting method (ie, steps S1 to S4 and S60, or steps S30 to S34 and S60) thus defines a method for producing a 3D shaped product 20. In this case, the method starts with Figure 4 Step S4 in or Figure 13 The process proceeds to step S34 in step S60. The next step S60 includes hot pressing a male mold tool 30 into the airlaid blank 10 to form a 3D shaped product 20 having a 3D shape at least partially defined by the male mold tool 30. The male mold tool 30 includes a protrusion 31 configured to be pressed into the airlaid blank 10, and the protrusion 31 is configured to align with a portion 11 of the airlaid blank 10 having a density different from the average density of the airlaid blank 10 during hot pressing.

[0138] In one embodiment, see Figure 4 、 6, 7 and 17, the method for producing a 3D shaped product 20 thus includes introducing natural fibers and a thermoplastic polymer binder and / or a mixture of natural fibers and a thermoplastic polymer binder into the upper end 112 of the forming head 110 in step S1. The method also includes conveying the natural fibers and the thermoplastic polymer binder and / or the mixture to the lower end 114 of the forming head 110 by applying a vacuum to an air-permeable collector 120 in step S2, the air-permeable collector 120 being arranged to be connected to the lower end 114 of the forming head 110. The method also includes capturing the natural fibers and the thermoplastic polymer binder and / or the mixture on the air-permeable collector 120 in step S3, and heating the natural fibers and the thermoplastic polymer binder and / or the mixture to form an air-laid blank 10 in step S4. The method additionally includes hot pressing a male mold tool 30 into the air-laid blank 10 in step S60 to form a 3D shaped product 20 having a 3D shape at least partially defined by the male mold tool 30. In this embodiment, the air-laid blank 10 comprises natural fibers at a concentration of at least 70% by weight of the air-laid blank 10 and a thermoplastic polymer binder selected in a concentration range of 2.5 to 30% by weight of the air-laid blank 10. The air-laid blank 10 has an average density, and a portion 11 of the air-laid blank 10 has a density different from the average density. The male mold tool 30 comprises a protrusion 31 configured to be pressed into the air-laid blank 10, and the protrusion 31 is configured to align with the portion 11 of the air-laid blank 10 having a density different from the average density of the air-laid blank 10 during heat pressing. In addition, the permeable collector 120 has an average air permeability. In this embodiment, the air permeability of the portion 121 of the permeable collector 120 is different from the average air permeability, and / or the object 125 is positioned on the portion 121 of the permeable collector 120. The portion 121 of the permeable collector 120 on which the object 125 is positioned has an air permeability that is different from the average air permeability. The portion 11 of the air-laid blank 10 aligned with the portion 121 of the permeable collector 120 has a density that is different from the average density. In addition, the air-laid blank 10 has two parallel planar major surfaces 12, 14.

[0139] In another embodiment, see Figure 6 、 13and 17, the method for producing a 3D formed product 20 thus includes introducing natural fibers and a thermoplastic polymer binder and / or a mixture of natural fibers and a thermoplastic polymer binder into the upper end 112 of the forming head 110 in step S30. The method also includes conveying the natural fibers and the thermoplastic polymer binder and / or the mixture to the lower end 114 of the forming head 110 in step S31, which is arranged to be connected to a belt collector 120 running between drive rollers 122, 124. The method also includes positioning the 3D object 127 on the belt collector 120 in step S32 and capturing the natural fibers and the thermoplastic polymer binder and / or the mixture on the belt collector 120 in step S33. The method additionally includes heating the natural fibers and the thermoplastic polymer binder and / or the mixture in step S34 to form the airlaid blank 10. The method further includes, in step S60, heat-pressing a male mold tool 30 into the airlaid blank 10 to form a 3D shaped product 20 having a 3D shape at least partially defined by the male mold tool 30. In this embodiment, the airlaid blank 10 comprises natural fibers at a concentration of at least 70% by weight of the airlaid blank 10 and a thermoplastic polymer binder selected from a concentration range of 2.5% to 30% by weight of the airlaid blank 10. The airlaid blank 10 has an average density, and a portion 11 of the airlaid blank 10 has a density different from the average density. The male mold tool 30 comprises a protrusion 31 configured to press into the airlaid blank 10, and the protrusion 31 is configured to align with the portion 11 of the airlaid blank 10 having a density different from the average density of the airlaid blank 10 during heat-pressing. In addition, the airlaid blank 10 has two parallel major surfaces 12, 14 and a thickness between the two parallel major surfaces 12, 14. The 3D object 127 defines holes 17 in the first major surface 14 of two parallel major surfaces 12, 14 and cavities 13 in the air-laid blank 10, and the density of the portion 11 of the air-laid blank 10 aligned with the cavity 13 is different from the average density of the air-laid blank 10.

[0140] In one embodiment, Figure 6 Step S60 in includes hot pressing the male mold tool 30 into the airlaid blank 10 by hot pressing a portion 11 of the airlaid blank 10 to be harder than the other portion 15 of the airlaid blank 10 to which the male mold tool 30 is engaged.

[0141] Figure 6 This step S60 in substantially corresponds to Figure 12 The various embodiments of step S20 described above are also applicable to Figure 6 Step S60 in .

[0142] In one embodiment, the above combination Figure 4-6 The methods described in 13-15 may include the additional step of smoothing the upper major surface 12 of the airlaid blank 10. In such an embodiment, the apparatus 100 for producing the airlaid blank 10 preferably comprises a device, tool or apparatus 140 for smoothing the upper major surface 12 of the airlaid blank 10, such as Figure 18 shown. The device, tool or apparatus 140 may be in the form of a brush or scraper arranged to remove any loose fibers from the upper major surface 12 and to smooth the surface 12 to be flat and smooth. The device, tool or apparatus 140 is advantageously arranged downstream of the forming head 110 and thereby engages the upper major surface 12 of the airlaid blank 10 as it is output from the forming head 110. In alternative embodiments, the device, tool or apparatus 140 may be arranged internally to the forming head 110, but is then preferably arranged close to or at the downstream outlet of the forming head 110 where the airlaid blank 10 is output from the forming head 110. The device, tool or apparatus 140 may also be arranged as Figure 7 The device 100 is shown.

[0143] The above embodiments are to be understood as a few illustrative examples of the present invention. Those skilled in the art will appreciate that various modifications, combinations, and variations of the embodiments may be made 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 in a concentration of at least 70% by weight of the airlaid blank (10); and a thermoplastic polymer binder selected in a concentration range of 2.5 up to 30% by weight of the airlaid web (10), wherein The air-laid blank (10) has an average density; The portion (11) of the airlaid blank (10) has a density different from the average density; and The airlaid blank (10) has two parallel planar major surfaces (12, 14), wherein said portion (11) of said airlaid blank (10) has a density that is lower than the average density prior to exposing said airlaid blank (10) to any compression.

2. The air-laid blank according to claim 1, wherein the portion (11) of the air-laid blank (10) has a two-dimensional extension parallel to the two parallel flat main surfaces (12, 14) and extends through the full thickness of the air-laid blank (10).

3. The air-laid blank according to claim 1, wherein The airlaid blank (10) comprises cavities (13) extending into but not through the full thickness of the airlaid blank (10); and The portion (11) of the airlaid blank (10) is aligned with the cavity (13).

4. The airlaid blank according to any one of claims 1 to 3, wherein the natural fibers are wood fibers.

5. The airlaid blank according to claim 4, wherein the natural fibers are cellulosic and / or lignocellulosic fibers.

6. The airlaid blank according to claim 4, wherein the natural fibers are cellulosic and / or lignocellulosic pulp fibers produced by chemical, mechanical and / or chemi-mechanical pulping of softwood and / or hardwood.

7. The air-laid blank according to claim 4, 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), mechanical fibers intended for medium density fiberboard, chemi-thermomechanical pulp (CTMP), and combinations thereof.

8. The airlaid blank of claim 4, wherein the natural fibers are cellulosic and / or lignocellulosic pulp fibers in a form selected from the group consisting of high temperature thermomechanical pulp (HTMP), high temperature chemical-thermomechanical pulp (HTCTMP), and combinations thereof.

9. The airlaid blank according to any one of claims 1 to 8, wherein the thermoplastic polymer binder is selected from the group consisting of thermoplastic polymer powders, thermoplastic polymer fibers, and combinations thereof.

10. The air-laid blank according to any one of claims 1 to 9, wherein the thermoplastic polymer binder is made of: 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, copolymers thereof and mixtures thereof, and ii) optionally one or more additives.

11. The airlaid blank according to any one of claims 1 to 10, wherein the average density is selected from 10 to 60 kg / m 3 within the range.

12. The air-laid blank according to claim 11, wherein the average density is selected from 15 to 60 kg / m 3 within the range.

13. The air-laid blank according to claim 12, wherein the average density is selected from 15 to 50 kg / m 3 within the range.

14. The airlaid blank according to claim 11, wherein the portion (11) of the airlaid blank (10) has a mass fraction of 1 to 50 kg / m 3 The density is selected within the interval .

15. The airlaid blank according to claim 14, wherein the portion (11) of the airlaid blank (10) has a mass fraction of 2.5 to 40 kg / m 3 The density is selected within the interval .

16. The airlaid blank according to claim 15, wherein the portion (11) of the airlaid blank (10) has a mass fraction of 2.5 to 30 kg / m 3 The density is selected within the interval .

17. The airlaid blank according to claim 16, wherein the portion (11) of the airlaid blank (10) has a mass fraction of 2.5 to 25 kg / m 3 The density is selected within the interval .

18. The airlaid blank according to any one of claims 1 to 17, wherein the airlaid blank (10) has a uniform thickness.

19. An air-laid blank according to any one of claims 1 to 18, wherein the density of the portion (11) of the air-laid blank (10) increases or decreases as the thickness of the air-laid blank (10) progresses from one of the two parallel flat major surfaces (12, 14) to the other of the two parallel flat major surfaces (12, 14).

20. A method of producing an airlaid blank (10), the method comprising: introducing (S1) natural fibers and a thermoplastic polymer binder and / or a mixture of said natural fibers and said thermoplastic polymer binder into an upper end (112) of a forming head (110); conveying (S2) the natural fibers and the thermoplastic polymer binder and / or the mixture to the lower end (114) of the forming head (110) by means of a vacuum applied to a permeable collector (120), the permeable collector (120) being arranged in connection with the lower end (114) of the forming head (110); capturing (S3) the natural fibers and the thermoplastic polymer binder and / or the mixture on the air-permeable collector (120); and heating (S4) the natural fibers and the thermoplastic polymer binder and / or the mixture to form an air-laid blank (10), wherein i) said airlaid blank (10) comprises said natural fibers in a concentration of at least 70% by weight of said airlaid blank (10) and said thermoplastic polymer binder in a concentration selected from the range of 2.5 up to 30% by weight of said airlaid blank (10); ii) the permeable collector (120) has an average air permeability; iiia) the portion (121) of the permeable collector (120) has an air permeability that is different from the average air permeability; and / or iiib) positioning an object (125) on a portion (121) of the permeable collector (120), wherein the portion (121) of the permeable collector (120) on which the object (125) is positioned has an air permeability that is different from the average air permeability; iv) the air-laid blank (10) has an average density; v) the portion (11) of said airlaid blank (10) aligned with said portion (121) of said air permeable collector (120) has a density different from said average density; and vi) the airlaid blank (10) has two parallel planar major surfaces (12, 14), wherein said portion (11) of said airlaid blank (10) has a density lower than said average density.

21. The method of claim 20, further comprising positioning (S10) the object (125) onto the permeable collector (120).

22. The method of claim 20 or 21, wherein the permeable collector (120) is a permeable belt collector (120) running between drive rollers (122, 124).

23. The method according to claim 21 or 22, wherein positioning (S10) the object (125) comprises positioning (S10) the object (125) on the permeable belt collector (120) at a position upstream of the forming head (110).

24. A method for producing a three-dimensional (3D) shaped product (20), the method comprising hot pressing (S20, S60) a male mold tool (30) into an airlaid blank (10) to form a 3D shaped product (20) having a 3D shape at least partially defined by the male mold tool (30), wherein The air-laid blank (10) comprises: natural fibers in a concentration of at least 70% by weight of the airlaid blank (10); and a thermoplastic polymer binder selected in a concentration range of 2.5 up to 30% by weight of the airlaid web (10), wherein The air-laid blank (10) has an average density; The density of the portion (11) of the airlaid blank (10) is different from the average density; The male tool (30) comprises protrusions (31) configured to press into the airlaid blank (10); and The protrusions (31) are configured to align with the portion (11) of the airlaid blank (10) during the heat pressing, the portion (11) having a density different from the average density of the airlaid blank (10), wherein said portion (11) of said airlaid blank (10) has a density lower than said average density.

25. The method of claim 24, further comprising: introducing (S1) the natural fibers and the thermoplastic polymer binder and / or a mixture of the natural fibers and the thermoplastic polymer binder into an upper end (112) of a forming head (110); conveying (S2) the natural fibers and the thermoplastic polymer binder and / or the mixture to the lower end (114) of the forming head (110) by means of a vacuum applied to a permeable collector (120), the permeable collector (120) being arranged in connection with the lower end (114) of the forming head (110); capturing (S3) the natural fibers and the thermoplastic polymer binder and / or the mixture on the air-permeable collector (120); and heating (S4) the natural fibers and the thermoplastic polymer binder and / or the mixture to form an air-laid blank (10), wherein i) the permeable collector (120) has an average air permeability; iia) the portion (121) of the permeable collector (120) has an air permeability that is different from the average air permeability; and / or iib) positioning an object (125) on a portion (121) of the permeable collector (120), wherein the portion (121) of the permeable collector (120) on which the object (125) is positioned has an air permeability that is different from the average air permeability; iii) the portion (11) of said airlaid blank (10) aligned with said portion (121) of said air permeable collector (120) has a density lower than said average density; and iv) The airlaid blank (10) has two parallel planar major surfaces (12, 14).

26. The method of claim 24, further comprising: introducing (S30) the natural fibers and the thermoplastic polymer binder and / or a mixture of the natural fibers and the thermoplastic polymer binder into an upper end (112) of a forming head (110); delivering (S31) the natural fibers and the thermoplastic polymer binder and / or the mixture to a lower end (114) of the forming head (110), the lower end (114) being arranged to be connected to a belt collector (120) running between drive rollers (122, 124); positioning (S32) a three-dimensional (3D) object (127) onto the belt collector (120); capturing (S33) the natural fibers and the thermoplastic polymer binder and / or the mixture on the belt collector (120); and heating (S34) the natural fibers and the thermoplastic polymer binder and / or the mixture to form an air-laid blank (10), wherein The air-laid blank (10) has two parallel major surfaces (12, 14) and a thickness between the two parallel major surfaces (12, 14); The 3D object (127) defines apertures (17) in a first major surface (14) of the two parallel major surfaces (12, 14) and cavities (13) in the airlaid blank (10); and The portion (11) of the airlaid blank (10) aligned with the cavity (13) has a density lower than the average density of the airlaid blank (10).

27. A method according to any one of claims 24 to 26, wherein the density of the portion (21) of the 3D formed product (20) is equal to or less than 4 times the average density of the 3D formed product (20), and the portion (21) of the 3D formed product (20) is formed by hot pressing the protrusion (31) into the portion (11) of the air-laid blank (10) having a density lower than the average density of the air-laid blank (10).

28. The method according to claim 27, wherein the density of the portion (21) of the 3D shaped product (20) is equal to or less than 2 times the average density of the 3D shaped product (20).

29. The method according to claim 28, wherein the density of the portion (21) of the 3D shaped product (20) is equal to or less than 1.5 times the average density of the 3D shaped product (20).

30. A method according to any one of claims 24 to 29, wherein hot pressing (S20, S60) comprises hot pressing (S20, S60) the male mold tool (30) into the air-laid blank (10) by hot pressing a portion (11) of the air-laid blank (10) to be harder than other portions (15) of the air-laid blank (10) to which the male mold tool (30) is engaged.

31. A method of producing an airlaid blank (10), said method comprising: introducing (S30) natural fibers and a thermoplastic polymer binder and / or a mixture of the natural fibers and the thermoplastic polymer binder into an upper end (112) of a forming head (110); delivering (S31) the natural fibers and the thermoplastic polymer binder and / or the mixture to a lower end (114) of the forming head (110), the lower end (114) being arranged to be connected to a belt collector (120) running between drive rollers (122, 124); positioning (S32) a three-dimensional (3D) object (127) onto the belt collector (120); capturing (S33) the natural fibers and the thermoplastic polymer binder and / or the mixture on the belt collector (120); and heating (S34) the natural fibers and the thermoplastic polymer binder and / or the mixture to form an air-laid blank (10), wherein said airlaid blank (10) comprising said natural fibers in a concentration of at least 70% by weight of said airlaid blank (10) and said thermoplastic polymer binder in a concentration selected from the range of 2.5 up to 30% by weight of said airlaid blank (10); The airlaid blank (10) has two parallel major surfaces (12, 14) and a thickness between the two parallel major surfaces (12, 14); and The 3D object (127) defines holes (17) in a first major surface (14) of the two parallel major surfaces (12, 14) and cavities (13) in the airlaid blank (10), wherein the density of the portion (11) of the airlaid blank (10) is different from the average density of the airlaid blank (10); wherein said portion (11) of said airlaid blank (10) has a density lower than said average density, wherein the portion (11) of the airlaid blank (10) aligned with the cavity (13) has a density that is different from the average density of the airlaid blank (10).

32. The method of claim 31 , wherein the airlaid blank (10) comprises the 3D object (127).

33. The method of claim 32, further comprising removing (S41) the 3D object (127) from the airlaid blank (10).

34. The method according to claim 33, wherein the 3D object (127) comprises a tracking device (128), the method further comprising identifying (S40) the 3D object (127) in the air-laid blank (10) based on the tracking device (128).

35. The method according to any one of claims 31 to 34, wherein positioning (S32) the 3D object (127) comprises: introducing (S50) the 3D object (127) into an airlock (135) of a positioning head (130), the positioning head (130) being arranged upstream of the forming head (110) but connected to the forming head (110) at least via a delivery opening (132); and The 3D object (127) is positioned (S51) on the belt collector (120) within the positioning head (130).

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