SE545563C2

SE545563C2 - Recyclable 3D shaped product for cushioning and/or thermal insulation of packaged goods

Info

Publication number: SE545563C2
Application number: SE2050890A
Authority: SE
Inventors: Maria Törnblom
Original assignee: Stora Enso Oyj
Priority date: 2020-07-09
Filing date: 2020-07-14
Publication date: 2023-10-24
Also published as: SE2050890A1

Abstract

A 3D shaped product (20) is formed by hot pressing of an air-laid blank (10) comprising natural fibers at a concentration of at least 70 % by weight of the air-laid blank and a thermoplastic polymer binder at a concentration selected within an interval of from 2.5 up to 30 % by weight of the air-laid blank. The 3D shaped product (20) is recyclable in a repulping process. At least a part of the thermoplastic polymer binder is water soluble at a repulping temperature of the repulping process. The 3D shaped product (20) are environmentally friendly alternatives to plastic 3D shaped products made by foamed polymers and can be recycled in existing recycling schemes.

Description

TECHNICAL FIELD The present embodiments generally relate to three dimensional (3D) shaped products, and in particular to 3D shaped products that can be recycled in a repulping process, and to methods for producing such 3D shaped products and to air-laid blanks.

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

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

The presence of binders in the methods described in U.S. patent application no. 2010/0190020 and European patent no. 1 446 286 presents several challenges from a recycling perspective. The binders are made to have very good attachment to the cellulose and/or lignocellulose ﬁbers in the air-laid blanks.

They also have very low solubility in water. Accordingly, the binders prevent effective disintegration of the 3D structures into single pulp ﬁbers when shearing in water in a repulping process. Furthermore, the binders leave may tacky impurities, often referred to as “stickies”, in the repulping process that severely restrict the usability of the recycled pulp acquired from the repulping process.

SUMMARY lt is an objective to provide 3D shaped products that are recyclable and methods for manufacturing such 3D shaped products. lt is a particular objective to provide such 3D shaped products that can be recycled in a repulping process.

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

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

An aspect of the invention relates to a 3D shaped product. The 3D shaped product is formed by hot pressing of an air-laid blank comprising natural fibers at a concentration of at least 70 % by weight of the air-laid blank and a thermoplastic polymer binder at a concentration selected within an interval of from 2.5 up to 30 % by weight of the air-laid blank. The 3D shaped product is recyclable in a repulping process. w . . , = . - -a ...y .\. >_\. _ » . ,-. ::\\- ïe-“t :Rs s i : \At least a part of the thermoplastic polymer binder is water soluble = at a repulping temperature of the repulping process Another aspect of the invention relates to an air-laid blank configured for hot pressing into a 3D shaped product. The air-laid blank comprises natural fibers at a concentration of at least 70 % by weight of the air-laid blank. The air-laid blank comprises a thermoplastic polymer binder at a concentration selected within an interval of from 2.5 up to 30 % by weight of the air-laid blank. The air-laid blank is recyclable in a repulping processgs least a part of the thermoplastic polymer binder is water soluble A further aspect of the invention relates to a method for manufacturing a 3D shaped product. The method comprises hot pressing of a male tool into an air-laid blank according to aboveg; The 3D shaped products of the present invention are useful as environmentally more friendly replacements to corresponding 3D shaped products made by polymers, for instance expanded polystyrene and plastic cutlery. The 3D shaped products are recyclable in a repulping process and can therefore be recycled in existing recycling schemes.

BRIEF DESCRIPTION OF THE DRAWINGS The embodiments, together with further objects and advantages thereof, may best be understood by making reference to the following description taken together with the accompanying drawings, in which: Fig. 1 is an illustrative embodiment of a cross section of a 3D shaped product; Fig. 2 schematically illustrates the 3D shaped product in Fig. 1 with different densities in different portions of the 3D shaped product; Fig. 3 schematically illustrates hot pressing of an air-laid blank to form the 3D shaped product shown in Fig. 1 prior to a male tool engaging the air-laid blank to produce a cavity; Fig. 4 schematically illustrates hot pressing of an air-laid blank to form the 3D shaped product shown in Fig. 1 when a male tool engages the air-laid blank; Fig. 5 is a schematic illustration of a male tool and a female tool configured to be used in hot pressing of an air-laid blank to form a 3D shaped product according to an embodiment; Fig. 6 is a ﬂow chart illustrating a method for manufacturing a 3D shaped product according to an embodiment; and Fig. 7 is an illustrative embodiment of a hard pressed 3D shaped product in the form of a spoon.

DETAILED DESCRIPTION The present embodiments generally relate to three dimensional (3D) shaped products, and in particular to 3D shaped products that can be recycled in a repulping process, and to methods for producing such 3D shaped products and to air-laid blanks. 3D shaped products of the present embodiments are useful as environmentally friendly replacements to corresponding 3D shaped products made by traditional foamed polymers, for instance expanded polystyrene (EPS) and polystyrene (PS). More sustainable alternatives to polymer products have been proposed in U.S. patent application no. 2010/0190020 and European patent no. 1 446 286, which both concern hot pressing of porous ﬁber mats (air-laid blank) produced by the process called air-laying into 3D structures with matched rigid molds or by membrane molding. The 3D shaped products produced in the above mentioned documents are, however, hard to recycle in existing recycling schemes. This is due to the presence of binders in the air-laid blanks. These binders are made to have very good attachment to the cellulose and/or lignocellulose ﬁbers in the air-laid blanks. They also have very low solubility in water. Accordingly, the binders prevent effective disintegration of the 3D shaped products into single pulp ﬁbers when shearing in water in a repulping process. Furthermore, the binders may leave tacky impurities, often referred to as “stickies”, in the repulping process that severely restrict the usability of the recycled pulp acquired from the repulping process.

The present invention relates to 3D shaped products that are recyclable in a repulping process. Hence, the 3D shaped products can be repulped into individual fibers when sheared with water in a repulping process. This means that the 3D shaped products of the present invention can be recycled in existing recycling schemes.

Generally, air-laid blanks and 3D shaped products made therefrom can be recycled if they can be disintegrated in an opener for this specific purpose and run through the air-laying process again with the possible addition of additional binder. This is in reality only possible for edge trim and other process rejects that are recycled in-house within the production facility. For consumers and other end users, this is not an option since there is no air-laying process in existing recycling schemes. A much better option would be if the products produced by or from air-laying could be sorted into one of the existing recycling fractions, for which there are already functioning collection and recycling systems. Since the majority of the material is made up of wood ﬁbers that could go into a paper or board making process these would be the natural, existing, fractions to collect the air-laid blanks and 3D shaped products with. With printing papers sensitive to impurities that can cause faults in the printing process or dark specs in the paper, the board fraction would typically be the better option. Recycled board is often used for mid-plies in box boards with several layers or ﬂuting in corrugated board. These are less sensitive to impurities, even those that decrease the strength of the recycled material.

An aspect of the invention relates to a 3D shaped product 20, The 3D shaped product 20 is formed by hot pressing of an air-laid blank 10, see Figs. 3 and 4, comprising see Fig. natural fibers at a concentration of at least 70 % by weight of the air-laid blank 10 and a thermoplastic polymer binder at a concentration selected within an interval of from 2.5 up to 30 % by weight of the air- laid blank 10. The 3D shaped product 20 is recyclable in a repulping process and at least a part of the thermoplastic polymer binder is water soluble at a repulping temperature of the repulping process.

The 3D shaped product 20 of the present embodiments is produced from the air-laid blank 10 in a hot pressing process. An air-laid blank 10, sometimes also referred to as dry-laid blank, air-laid mat, dry-laid mat, air-laid web or dry-laid web, is formed by a process known as air-laying, in which natural fibers and binders are mixed with air to form a porous fiber mixture. This ﬁber mixture constituting an air-laid blank 10 is characterized by being porous, having the character of an open cell foam and being produced in a so-called dry production method, i.e., no addition of water. The air-laying process was initially described in U.S. patent no. 3,575,749. The air-laid blank 10 may be in the form as produced in the air-laying process. Alternatively, the air-laid blank 10 may be in an at least partly processed form, such as by being cut into a given form prior to hot pressing.

Hot pressing as used herein indicates that the air-laid blank 10 is exposed to pressure exerted by pressing a male tool 30 or a male tool 30 and a female tool 50 into the air-laid blank 10 or moulding the air-laid blank 10 in matched molds (male tool 30 and female tool 50) while the air-laid blank 10 is heated or exposed to heat, see Figs. 3 to 5. Hence, hot pressing implies that the pressing is done at a temperature above room temperature, preferably at a temperature at which the thermoplastic polymer binder is malleable, or in the case of hard pressed products, at a temperature at which the thermoplastic polymer binder is melted.

The 3D shaped products 20 of the present embodiment are recycleable, i.e., repulpable, in a repulping process. This is possible since at least a part of the thermoplastic polymer binder in the air-laid blank 10 is water soluble at a repulping temperature of the repulping process. Water soluble as used herein imp|ies that the thermoplastic polymer binder disso|ves or disperses in water during the repulping process. For instance, the thermoplastic polymer binder may disso|ve or disperse in water at the repulping temperature of the repulping process, i.e., forms a solution or colloidal dispersion, in which the thermoplastic polymer binder exists as single molecules and/or form colloidal aggregates. Water soluble as used herein implies~_» «~ ~ w v w ~ * .' .~.~ .~ ~ . :W .\;.._.\\_.\_.\;_.\_.>,.__.\ _.\ _..\»~ »ywf v \ tﬂmq .\,.- “av 1 . \.\ NN; h, _._.“. .\,.- t..sal~,\\.~\.~~\-\..~\.~ w v. -.~. :_ .....s,~\.-~ ».~\.~~ ~ . . du.. .\\.-.\\.-~; a solubility of ftñfrft: äïiaïï *ïíf g least 1 g thermoplastic polymer binder per 100 mL water, and more preferably at least 5 g thermoplastic polymer binder per 100 mL water, such as at least 10 g thermoplastic polymer binder per 100 mL water. Hence, at least a part of the thermoplastic polymer binder that is water soluble ' :ïtaèyhas water solubility in accordance with above.

“Repulpability” and “recyclability” in paper or board processes are most widely tested using the PTS- method PTS-RH 021/97 from the German Papiertechnische Stiftung. For board products, the PTS- method tests the recyclability in tvvo steps, where the first is a repulpability test. ln the repulpability test, 50 g of material is disintegrated in a standard disintegrator for 20 min at conditions as speciﬁed in PTS- method PTS-RH 021/97. The undispersed residue is screened out and its weight is determined. lf the weight of this undispersed residue corresponds to less than 20% of the original weight (50 g), the material is classified as “recyclable”. lf the weight of the undispersed residue is 20-50% of the original weight, the material is classiﬁed as “recyclable but worthy of product design improvement”. ln more detail, the PTS-method PTS-RH 021/97 comprises disintegrating the specimens in line with DIN EN ISO 5263-1:2004-12, but using tap water of 40°C. The dilution water is poured over the sample material, which is placed in the disintegrator (Standard disintegrator to DIN EN ISO 5263-1:2004-12) without pre-swelling. The sample material is disintegrated at a consistency of 2.5 % o.d. corresponding to a weighed-in amount of 50 g o.d. and a slurry volume of 2 L. The disintegration period is 20 min (60,000 revolutions). After disintegrating, the pulp (total stock) is completely transferred to a standard distributor (Standard distributor to ZELLCHEMING Technical lnformation Sheet ZM V/6/61) and diluted with tap water to a total volume of 10 L, which corresponds to 0.5 % consistency. The screening is conducted in line with ZELLCHEMING Technical lnformation Sheet ZM V/18/62 using a perforated plate of 0.7 mm hole diameter. The test device is set to the "low stroke" mode. A test portion of the slurry corresponding to 2 g o.d. (400 ml) is taken out of the distributor and diluted to a total volume of 1000 mL, which is filled into the fractionator during 30 s and screened for 5 min at a washing water pressure of 0.3 bar. After 5 min, the water supply and the membrane displacement motor are cut off. The valve on the retaining ring is opened to drain the water which has gathered below the test chamber. The locking screw is loosened and the test chamber is tilted upwards. The rear nozzles are covered with one hand to prevent waterfrom dripping onto the unprotected perforated plate with the residue on it. All residue from the perforated plate is washed into a 2 L tank and dewatered through a ﬁlter inserted in a Büchner funnel. The ﬁlter is folded once and placed in the dryer to dry at 105 °C up to weight constancy. Products are rated as "recyclable" if the disintegration residue does not exceed 20 % in relation to the input and rated as “recyclable, but worthy of product design improvement” if the disintegration residue is from 20 % to 50 % of the input.

The second part of the PTS-method PTS-RH 021/97 for board products is a test for impurities, especially substances that become extremely tacky when heated, in the test to 130°C. ln the board making process, such sticky or tacky substances can attach to machine fabrics and other essential parts of the board machine and cause runability problems and the need for extended, costly, cleaning stoppages. ln the paper and board industry, this type of impurities are usually called “stickies”. The presence of such stickies in the unscreened, disintegrated sample render the material classiﬁed as “non-recyclable due to stickies”. The presence of other impurities can restrict the usability of the recycled pulp acquired from the material but is not considered totally detrimental.

Hence, in an embodiment, the 3D shaped product 20 is repulpable in accordance with PTS-method PTS- RH 021/97. For instance, the weight of any undispersed residue of the 3D shaped product 20 when sheared with water in a disintegrator for 20 min in the repulping process corresponds to less than 50 % (w/w), preferably less than 20 % (w/w), of the weight of the 3D shaped product 20. Thus, in a particular embodiment, the air-laid blank 10 and preferably the 3D shaped product 20 results in less than 50 % (w/w), preferably less than 20 % (w/w), of undispersed residue following disintegration of 50 g of the air- laid blank 10 or 3D shaped product 20 in a standard disintegrator for a 20 min at conditions as specified in PTS-method PTS-RH 021/ The repulping temperature used in the repulping process is the range of from 20 to 100°C, such as within the range of from 30 to 90°C, and typically within the range of from 30 to 70°C. Hence, least a part of the thermoplastic polymer binder is water soluble at a temperature selected within an interval of from 20 to 100°C, preferably within an interval of from 30 to 90°C, and more preferably within an interval of from 30 to 70°C. ln a particular embodiment, the temperature of water used in the repulping process is about 40°C in accordance with the PTS-method PTS-RH 021/ ln an embodiment, the natural ﬁbers are wood ﬁbers. ln a particular embodiment, the natural ﬁbers are cellulose and/or lignocellulose ﬁbers. Hence, in an embodiment, the natural fibers contain cellulose, such as in the form of cellulose and/or lignocellulose, i.e., a mixture of cellulose and lignin. The natural fibers may also contain lignin, such as in the form of lignocellulose. The natural ﬁbers may additionally contain hemicellulose. ln a particular embodiment, the natural ﬁbers are cellulose and/or lignocellulose pulp fibers produced by chemical, mechanical and/or chemo-mechanical pulping of softvvood and/or hardwood. For instance, the cellulose and/or lignocellulose pulp ﬁbers are in a form selected from the group consisting of sulfate pulp, sulﬁte pulp, thermomechanical pulp (TMP), high temperature thermomechanical pulp (HTMP), mechanical ﬁber intended for medium density ﬁberboard (MDF-fiber), chemo-thermomechanical pulp (CTMP), high temperature chemo-thermomechanical pulp (HTCTMP), and a combination thereof.

The natural ﬁbers can also be produced by other pulping methods and/or from other cellulosic or lignocellulosic raw materials, such as ﬂax, jute, hemp, kenaf, bagasse, cotton, bamboo, straw or rice husk.

The air-laid blank 10 comprises the natural ﬁbers in a concentration of at least 70 % by weight of the air- laid blank 10. ln a preferred embodiment, the air-laid blank 10 comprises the natural fibers in a concentration of at least 72.5 %, more preferably at least 75 %, such as at least 77.5 %, at least 80 %, at least 82.5 %, at least 85 % by weight of the air-laid blank 10. ln some applications, even higher concentrations of the natural fibers may be used, such as at least 87.5 %, or at least 90 %, at least 92.5 %, at least 95 % or at least 97.5 % by weight of the air-laid blank The thermoplastic polymer binder is included in the air-laid blank 10 as binder to bind the air-laid blank 10 together and preserve its form and structure during use, handling and storage. The thermoplastic polymer binder may also assist in building up the foam-like structure of the air-laid blank 10. The thermoplastic polymer binder is intermingled with the natural ﬁbers during the air-laying process forming a fiber mixture. The thermoplastic polymer binder may be added in the form of a powder, but * “^“.¿;¿ﬁbers that are intermingled with the natural ﬁbers in the air-laying process.

Alternatively, or in addition, the thermoplastic polymer binder may be added as solution, emulsion or dispersion into and onto the air-laid blank 10 during the air-laying process. This latter technique is most suitable for thin air-laid blanks ln an embodiment, the thermopiastic polymer binder has a softening or melting point not exceeding a degradation temperature of the natural ﬁbers. Hence, the thermopiastic polymer binder thereby becomes softened or melted at a process temperature during the hot pressing that does not exceed the degradation temperature of the natural ﬁbers. This means that the thermopiastic polymer binder becomes malleable or melted at a temperature that does not degrade the natural fibers in the air-laid blank ln an embodiment, the thermopiastic polymer binder is preferably polar to promote solubility in water during the repulping process. Polar thermopiastic polymer binders also have a good adhesion to cellulose and/or lignocellulose ﬁbers, i.e., the natural fibers of the air-laid blank . t ;- ..-\ .MN . +:\.*~~:t1~::~~\*à?:+ 1 “ component thermopiastic polymer ﬁbers. Bi-component thermopiastic polymer ﬁbers, also known as bico ﬁbers, comprise a core and sheath structure, where the core is made from a ﬁrst polymer, copolymer and/or polymer mixture and the sheath is made from a second, different polymer, copolymer and/or polymer mixture. »å-fgïhe mono-component thermopiastic polymer fibers are water soluble at the repulping temperature. Correspondingly, at least a sheath component of the bi-component thermopiastic polymer fibers is water soluble at the repulping temperature. ln embodiment, both the sheath component and the core component of the bi-component thermopiastic polymer ﬁbers are water soluble at the repulping temperature.

Examples of such water soluble thermopiastic polymer materials are polyvinyl alcohol (PVA), polyethylene glycol (PEG), poly(2-ethyl-2-oxazoline) (PEOX), polyvinyl ether (PVE), polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMAA) and copolymers and/or mixtures thereof. ln an embodiment, the thermopiastic polymer binder is or comprises, such as consists of, mono- component thermopiastic polymer ﬁbers made of a material selected from the group consisting of PVA, PEG, PEOX, PVE, PVP, PAA, PMAA and copolymers and/or mixtures thereof. ln another embodiment, the thermoplastic polymer binder is or comprises, such as consists of, bi- component thermoplastic polymer ﬁbers having a sheath or a sheath and core made of a material or materials selected from the group consisting of PVA, PEG, PEOX, PVE, PVP, PAA, PMAA and copolymers and/or mixtures thereof. ln a particular embodiment, at least the sheath of the bi-component thermoplastic polymer ﬁbers is made of a material selected from the group consisting of PVA, PEG, PEOX, PVE, PVP, PAA, PMAA and copolymers and/or mixtures thereof. ln such a particular embodiment, also the core of the bi-component thermoplastic polymer ﬁbers could be selected from this group. However, if the core of the bi-component thermoplastic polymer fibers does not soften to become tacky and attach to the natural ﬁbers in the hot pressing the core may actually be made of a material that are not necessarily water soluble at the repulping temperature. This means that the core could be made of a thermoplastic polymer that is not necessarily water soluble at the repulping temperature. Hence, in this particular embodiment, the bi-component thermoplastic polymer fibers comprise a core component made of 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) and copolymers and/or mixtures thereof, and a sheath component made of a material selected from the group consisting of PVA, PEG, PEOX, PVE, PVP, PAA, PMAA and copolymers and/or mixtures thereof. ln a further embodiment, the thermoplastic polymer binder is or comprises, such as consists of, a combination of mono-component thermoplastic polymer ﬁbers made of a material selected from the group consisting of PVA, PEG, PEOX, PVE, PVP, PAA, PMAA and copolymers and/or mixtures thereof, bi-component thermoplastic polymerfibers having a core and sheath made of a material or materials selected from the group consisting of PVA, PEG, PEOX, PVE, PVP, PAA, PMAA and copolymers and/or mixtures thereof and/or bi-component thermoplastic polymer fibers having a sheath made of a material selected from the group consisting of PVA, PEG, PEOX, PVE, PVP, PAA, PMAA and copolymers and/or mixtures thereof and a core made of a material selected from the group consisting of PE, EAA, EVA, PP, PS, PBAT, PBS PLA, PET, PCL and copolymers and/or mixtures thereof.

The thermoplastic polymer binder could be made of a single type of thermoplastic polymer fibers, i.e., made of a same material in the case of mono-component thermoplastic polymer ﬁbers or made of the same material or materials in the case of bi-component thermoplastic polymer ﬁbers. However, it is also possible to use a thermoplastic polymer binder made of multiple different mono-component thermoplastic polymer ﬁbers made of different materials and/or multiple different bi-component thermoplastic polymer ﬁbers made of different materials.ln an embodiment, the thermoplastic polymer binder šsæssﬂcomprises a thermoplastic polymer powder made of a material selected from the group consisting of PVA, PEG, PEOX, PVE, PVP, PAA, PMAA and copolymers and/or mixtures thereof.

The major portion of the thermoplastic polymer binder in the air-laid blank 10 is water soluble. The air- laid blank 10 may, though, comprise some thermoplastic po|ymer(s) that are not water soluble at the repulping temperature of the repulping process as long as the 3D shaped product 20 is repulpable, such as in accordance with PTS-method PTS-RH 021/97. Hence, the thermoplastic polymer binder may be a mixture of water soluble thermoplastic po|ymer(s) and thermoplastic po|ymer(s) not being water soluble at the repulping temperature of the repulping process as long as the 3D shaped product 20 is repulpable. ln an embodiment, the thermoplastic polymer binder is water soluble. “ffåfïhe air-laid blank 10 comprises the thermoplastic polymer binder at a concentration selected within an interval of from 2.5 up to 30 % by weight of the air-laid blank 10. ln some applications, it may be desirable to have comparatively low concentrations of the thermoplastic polymer binder, such as from 2.5 up to 15 % by weight of the air-laid blank 10, preferably within an interval of from 4 up to 15 % by weight of the air-laid blank 10, or from 5 up to 15 % by weight of the air-laid blank 10, such as from 7.5 up to 15 % by weight of the air-laid blank 10, and more preferably within an interval of from 10 up to 15 % by weight of the air-laid blank 10. ln other applications, a higher concentration of the thermoplastic polymer binder may be advantageous, such as from 10 up to 30 %, for instance from 15 up to 30 % by weight of the air-laid blank 10. ln a particular embodiment, the air-laid blank 10 comprises more than 15 % but no more than 30 % by weight of the thermoplastic polymer binder. For instance, the air-laid blank 10 comprises the thermoplastic polymer binder at a concentration selected within an interval of from 15 or 17.5 up to 30 % by weight of the air-laid blank 10. ln a particular embodiment, the air-laid blank 10 comprises the thermoplastic polymer binder at a concentration selected within an interval of from 15 or 17.5 up to 25 %, such as from 20 up to 25 % by weight of the air-laid blank 10. lt may, in some applications, be advantageous to have a comparatively higher concentration of the thermoplastic polymer binder, such as more than 15 % by weight of the air-laid blank 10, in order to preserve the porosity and foam-like structure of the air-laid blank 10 even when not pressing the air-laid blank 10 that hard to get porous 3D shaped products 20. Generally, a lower concentration of the thermoplastic polymer binder could be used when hard pressing the air-laid blank 10 during the hot pressing, whereas a comparativelyhigher concentration of the thermoplastic polymer binder is needed if the air-laid blank 10 is not pressed hard during the hot pressing. ln an embodiment, the 3D shaped product 20 is configured to protect packaged goods from electrostatic discharge (ESD). ln such an embodiment, the air-laid blank 10 is electrically conducting or semiconducting. For instance, the air-laid blank 10 could comprise an electrically conducting polymer or electrically conducting ﬁbers to make the air-laid blank 10 and, thereby, the 3D shaped product 20 formed by hot pressing the air-laid blank 10, electrically conducting or semiconducting. ln such a case, the air laid blank 10 preferably comprises the electrically conducting polymer or fibers at a concentration of no more than 10 % by weight of the air-laid blank 10, and more preferably of no more than 5 % by weight of the air-laid blank 10. ln an embodiment, a portion of the natural fibers may be replaced with electrically conducting polymer or fibers. ln another embodiment, the binder is made of, or comprises, an electrically conducting polymer. ln a further embodiment, these tvvo embodiments are combined. ln a particular embodiment, the electrically conducting polymer or fibers are carbon fibers. lnstead of, or as a complement to, having electrically conducting polymer or fibers, the air-laid blank 10 could comprise an electrically conducting or semiconducting ﬁller, such as carbon black, which, for instance, could be in the form of an additive to the binder. ln some applications, it may be desirable to seal some or all of the surfaces of the 3D shaped product 20, such as by heat, to prevent linting from the surface(s) onto the packaged goods. Surfaces that are processed with heat in the hot pressing will be sealed and do not need any additional (heat) sealing. The at least one surface to be sealed can be sealed, such as by heat, before or after the hot pressing operation. Hence, in an embodiment, the 3D shaped product 20 comprises at least one surface 21, 23 that is heat sealed to inhibit linting from the at least one surface 21, 23. Fig. 1 illustrates a 3D shaped product 20 having an upper surface 22, a bottom surface 24 and tvvo end surfaces 21, 23. A 3D shaped cavity 26 is formed in the upper surface 22 in the hot pressing to thereby impart a 3D shape of the 3D shaped product 20. The end surfaces 21, 23 may then be unprocessed from the air-laid blank 10 or may have been produced by sawing, cutting or stamping the air-laid blank 10 to produce these end surfaces 21, 23. ln such a case, it may be preferred to heat seal these surfaces 21, 23 to prevent or at least suppress or inhibit linting. The upper surface 22, or at least a portion thereof, has been hot pressed so no heat sealing thereof is generally needed. Heat sealing of the bottom surface 24 may be applied depending on whether the bottom surface of the air-laid blank 10 has been exposed to any heat during the hot pressing.ln some applications, the 3D shaped product 20, or at least a portion thereof, can be laminated with a surface layer, such as a thermoplastic polymer film or non-woven textile. This can both prevent linting and add additional functions to the surface, such as moisture barriers, haptic properties, color and designs. The film or non-woven textile could be made from any common thermoplastic polymer. The film or non-woven textile should, however, dissolve or peel off the 3D shaped product 20 in the repulping process and thereby be removed during the repulping process. Examples include the previously mentioned thermoplastic polymer materials for usage as thermoplastic polymer binder. This layer could be heat laminated to the air-laid blank 10 by being semi melted or attached with a water soluble hot-melt glue and/or applied directly, such as by extrusion, onto the air-laid blank 10 or the 3D shaped product 20. ln an embodiment, the film laminated to at least one surface, or a portion thereof, of the 3D shaped product 20 is electrically conducting or semiconducting to provide ESD protection of the packaged goods. ln an embodiment, the surface layer is attached to the at least one surface of the 3D shaped product 20 by a water soluble hotmelt glue and/or by a water soluble adhesive ﬁlm. ln further embodiments, it is possible to apply the surface layer by spraying it onto surface(s) of the 3D shaped product 20 or the air-laid blank 10. The layer may then contain any substances that can be prepared as solutions, emulsions or dispersions, such as thermoplastic polymers; natural polymers, such as starch, agar, guar gum or locust bean gum, microfibrillar or nanoﬁbrillar cellulose or lignocellulose or mixtures thereof. The surface layer may in addition comprise other substances, such as emulsifying agents, stabilizing agents, electrically conductive agents, etc. that provide additional functionalities to the surface layer and the 3D shaped product The 3D shaped product 20 of the embodiments could be used as an environmentally friendly alternative to single use items and products that are traditionally made of plastics. For instance, the 3D shaped product 20 could be manufactured as a cup, tray, bowl or beaker used for packaging of or containing food products. The recyclable 3D shaped product 20 could also be in the form of recyclable single use cutlery items including, for instance, knives, forks, spoons and stirrers as schematically shown in Fig. 7. ln these cases, the hot pressing is performed at comparatively higher pressures to increase the density of the 3D shaped product 20 to about 10 to 50 times the density of the air-laid blank 10 and thereby fully consolidate the material.

The 3D shaped product 20 could be in the form of a 3D shaped packaging product 20 for cushioning and/or thermal insulation of packaged goods, such as inserts of suitable form into packaging andprotection of goods. ln these applications, the 3D shaped product 20 preferably retains at least a portion of the porosity and open cell foam structure of the air-laid blank 10 even after hot pressing and have therefore excellent shock absorbing and thermally insulating properties. The 3D shaped products 20 could thereby be produced to have geometries, i.e., 3D shape, suitable for protection of goods during transport and/or storage. The preservation of the porous character of the air-laid blank starting material means that the 3D shaped products 20 could be used to protect not only consumer goods and products but also heavy equipment against impact. Furthermore, the porous 3D shaped products 20 have improved thermally insulting properties as compared to compact and dense 3D shaped products with thin cross sections. This means that the 3D shaped products 20 can also, or alternatively, be used for storage and/or transport of goods that need to be kept cold, such as cold provisions, or need to be kept hot or warm, such as ready meals. ln an embodiment, the 3D shaped product 20 has a density that is less than four times a density of the air-laid blank The 3D shaped product 20 of these embodiments is produced from the air-laid blank 10 in a hot pressing process that preserves at least some of the porosity of the air-laid blank 10. Hence, the density of the 3D shaped product 20 is less than four times the density of the air-laid blank 10. The prior art hot pressing processes that produce dense 3D shaped products with thin cross sections typically increase the density of the 3D shaped products with several tens of the density of the air-laid blank, such as 10 to 50 times. The significant increase in density of the prior art 3D shaped products means that most of the porosity of the air-laid blank is lost resulting in a dense and compact ﬁber structure. The comparatively lower increase in density according to these embodiments in clear contrast preserves the porous structure of the air-laid blank 10 also in the formed 3D shaped product The density of the 3D shaped product 20 as used herein is the average or mean density of the 3D shaped product 20. This means that the 3D shaped product 20 may contain portions or parts 25A, 25B, 25C, 25D, 25E, see Fig. 2, with different porosity and thereby different densities. This is due to hot pressing different parts of the air-laid blank 10 at different levels or amounts due to the shape of a male tool 30 employed in the hot pressing, see Figs. 3 and 4. The different densities in the different parts 25A, 25B, 25C, 25D, 25E of the 3D shaped product 20 are schematically shown with different gray scale patterns in Fig. 2. For instance, the parts of the air-laid blank 10 aligned with the protruding structures 32 of the male tool 30 will be pressed and compacted harder as compared other parts of the air-laid blank 10. As a consequence, the parts 25C, 25E of the 3D shaped product 20 aligned with the protruding structures 32 of the male tool 30 will have higher densities as compared to other parts 25A, 25B, 25D of the 3D shaped product 20. The density of the 3D shaped product 20 is, however, the average or mean density rather than densities of different parts thereof, and represents the total mass of the 3D shaped product 20 divided by the volume of the 3D shaped packaging product 20 excluding any cavities 26 in the 3D shaped product 20 formed during the hot pressing by the male tool 30 and/or a female tool 50, see Fig. ln an embodiment, the density of the 3D shaped product 20 is equal to or less than three times the density of the air-laid blank 10. ln a particular embodiment, the density of the 3D shaped product 20 is equal to or less than twice the density of the air-laid blank Hence, according to the invention the hot pressing of the air-laid blank 10 leads to an increase in density of the 3D shaped product 20 as compared to the density of the air-laid blank 10 of no more than 300 %, preferably no more than 250 %, and more preferably no more than 200 %, 150 % or most preferably of no more than 100 %.

The hot pressing, however, preferably causes an increase in the density of the 3D shaped packaging product 20 as compared to the density of the air-laid blank 10 due to hot pressing of the male tool 30 or the male tool 30 and the female tool 50 into the air-laid blank 10. The increase in density caused by the hot pressing is preferably at least 10 %, such as at least 12.5 %, at least 15 %, at least 17.5 %, at least 20 %, at least 22.5 %, at least 25%, or even higher, such as at least 30 %, at least 40 %, at least 50 %, at least 60 %, at least 70 %, at least 80 %, at least 90 % or at least 100 %. ln various embodiments, the increase in density caused by the hot pressing is at least 12.5 % but no more than 300 %, such as at least 15 % but no more than 275 %, at least 17.5 % but no more than 250 %, at least 20 % but no more than 225 %, such at least 22.5 % but no more than 200 %. ln an embodiment, the density of the air-laid blank 10 is selected within an interval of from 10 to 60 kg/m3. ln an embodiment, the density of the 3D shaped product 20 is selected within an interval of from 15 to 240 kg/m ln an embodiment, the air-laid blank 10 has a thickness of at least 20 mm, preferably at least 30 mm and more preferably at least 40 mm. Hence, such embodiments use rather thick air-laid blanks 10 to get 3D shaped products 20 suitable for cushioning and/or thermal insulation even after hot pressing. Thethickness of the air-laid blank 10 may be selected based on the particular use of the resulting 3D shaped product 20, such as based on the cushioning and/or isolation requirements for the 3D shaped product 20 and/or based on the geometries of the packaged goods that are to be protected by the 3D shaped product Another aspect of the invention re|ates to an air-laid blank 10 conﬁgured for hot pressing into a 3D shaped product 20. The air-laid blank 10 comprises natural ﬁbers at a concentration of at least 70 % by weight of the air-laid blank 10. The air-laid blank 10 also comprises a thermoplastic polymer binder at a concentration selected within an interval of from 2.5 up to 30 % by weight of the air-laid blank 10. The air-laid blank 10 is recyclable in a repulping processesxf %~.t least a part of the thermoplastic polymer binder is water soluble at a repulping temperature of the repulping process The disclosure above of various embodiments of the thermoplastic polymer binder and the natural ﬁber discussed in connection with the 3D shaped product 20 can also be applied to the air-laid blank 10 of the present invention.

Another aspect of the embodiments re|ates to a method for manufacturing a 3D shaped product 20, see Figs. 3 to 6. The method comprises hot pressing, in step S1, of a male tool 30 into an air-laid blankaccording to the present invention to form the 3D shaped product ln an embodiment, step S1 in Fig. 6 comprises hot pressing of a heated male tool 30 into the air-laid blank 10. ln this embodiment, the heated male tool 30 is preferably heated to a temperature selected within an interval of from 120°C up to 210°C, preferably within an interval of from 120°C up to 190°C. Hence, in this embodiment, the heating of the air-laid blank 10 is achieved by usage of a heated male tool 30. The male tool 30 may then comprise heating elements 38 that are preferably controllable heating elements 38 to heat the male tool 30 to a desired temperature for hot pressing. The temperature of themale tool 30 typically depends on the type of natural fibers and the thermoplastic polymer binder in the air-laid blank 10 and the cycle time of the hot pressing in step S1 . However, the above presented interval is suitable for most combinations of natural fibers, thermoplastic polymer binders and cycle times. ln an embodiment, the air-laid blank 10 is positioned on base platen 40 as shown in Figs. 3 and 4. ln an embodiment, step S1 in Fig. 6 comprises hot pressing of the heated male tool 30 into the air-laid blank 10 positioned on a base platen 40 having a temperature equal to or below ambient temperature. ln these embodiments, the heating of the air-laid blank 10 is achieved by the male tool 30, whereas the base platen 40 is at ambient temperature, typically room temperature, or may even be cooled. Having a base platen 40 at ambient temperature or even cooled may reduce the risk of heating the air-laid blank 10 too much during the hot pressing in step S1, which othen/vise may have negative consequences of degrading the natural ﬁbers, melting the thermoplastic polymer binder and destroying the porous structure of the air-laid blank 10 and the formed 3D shaped product lt is, though, possible to have the air-laid blank 10 positioned on a heated base platen 40 during the hot pressing in step S1 even in combination with a heated male tool 30. ln such a case, also the underside of the air-laid blank 10 facing the heated base platen 40 will be heat sealed during the hot pressing. ln another embodiment, see Fig. 5, step S1 comprises hot pressing of the heated male tool 30 and a heated female tool 50 into the air-laid blank 10 positioned in between the heated male tool 30 and the heated female tool 50 to form the 3D shaped product 20 having the 3D shape at least partly deﬁned by the male tool 30 and the female tool 50. ln an embodiment, the male tool 30 forms a 3D shaped cavity 26 in the formed 3D shaped packaging product 20, whereas the female tool 50 comprises a 3D shaped cavity 52 that defines the outer geometry and 3D shape of the 3D shaped product Matched male tool 30 and female tool 50 could also be used during the hot pressing similar to molds to form 3D shaped product 20, such as in the form of cutlery or other products with a, for most parts, thin and consolidated cross section. ln such a case, the air-laid blank 10 is positioned between the male tool 30 and the female tool 50 during the hot pressing to form a 3D shaped product 20 having the 3D shape at least partly defined by the male tool 30 and the female tool ln an embodiment, both the male tool 30 and the female tool 50 are heated, preferably to a temperature selected within an interval of from 120°C up to 210°C, preferably within an interval of from 120°C up to190°C. The male tool 30 and the female tool 50 may be heated to the same temperature or to different temperatures. ln another embodiment, one of the male tool 30 and the female tool 50 is heated, while the other is at ambient temperature. ln the above presented embodiments, at least one of the tools 30, 50 used in the hot pressing in step S1 is heated. ln another embodiment, the method comprises heating at least a portion of the air-laid blank 10 prior to hot pressing, in step S1 in Fig. 6, of the male tool 30 into the air-laid blank 10 or pressing or molding the air-laid blank 10 between the male tool 30 and the female tool Hence, rather than heating the male tool 30 and/or any female tool 50, the air-laid blank 10 is heated, preferably prior to the hot pressing operation. The air-laid blank 10 is then preferably heated to a temperature where the thermoplastic polymer binder is in a malleable but not melted state. For most thermoplastic polymer binders this temperature is within an interval of from 80°C up to 180°C, such as from 100°C up to 180°C or from 120°C up to 160°C. Hence, in an embodiment, the air-laid blank 10 is preferably heated to a temperature within the interval of from 80°C up to 180°C. ln this embodiment, the male tool 30 and the base platen 40 or female tool 50 may independently be at ambient temperature, such as room temperature, or cooled. ln an embodiment, heating of the air-laid blank 10 could be combined with usage of a heated male tool 30 or a male tool 30 and a female tool 50, of which at least one is heated. ln some applications, especially for hard pressed products, the air-laid blank 10 needs to be dried, such as by heating, prior to hot pressing. ln such a case, the air-laid blank 10 may be heated before the hot pressing and is then heated further by the heated tools 30, 50 in the hot pressing operation.

The overall 3D shape of the 3D shaped product 20 is at least partly deﬁned by the male tool 30, sometimes creating at least one cavity 26 within the 3D shaped product 20, and by the optional female tool 50 that deﬁnes at least partly the outer shape of the 3D shaped product 20. The 3D shape and geometries of the 3D shaped product 20 are at least partly selected based on the shape of the packaged goods that should be protected by the 3D shaped product 20 or by the intended use of the 3D shaped product 20, such as in the form of a food container, etc.ln an embodiment, step S1 comprises hot pressing of the male tool 30 into the air-laid blank 10 at an average pressure equal to or below 200 kPa. ln a particular embodiment, the male tool 30 is hot pressed into the air-laid blank 10 at a pressure equal to or below 175 kPa, and more preferably equal to or below 150 kPa. ln embodiments, where the air-laid blank 10 is hard pressed between the male tool 30 and the female tool 50 a pressure above 1 MPa may be used, including above 5 MPa, above 10 MPa, aboveMPa or even above 20 MPa.

The method may also comprise an additional step of cutting the air-laid blank 10 and/or the 3D shaped product 20 into a desired shape, such as by a saw, a cutter, or stamping die. This cutting operation may be performed prior to the hot pressing, simultaneously with the hot pressing and/or after the hot pressing. ln an embodiment, step S1 of Fig. 6 is performed without water. Hence, no water is added during the hot pressing operation. The air-laid blank 10 is preferably at ambient equilibrium moisture content or may be dried.

The method described above and shown in Fig. 6 is suitable to form a 3D shaped product 20 according to the present invention.

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

Claims

1. Athree-dimensional(3D)shaped product ' the 3D shaped product (20) is formed by hot pressing of an air-laid blank (10) comprising natural ﬁbers at a concentration of at least 70 % by weight of the air-laid blank (10) and a thermoplastic polymer binder at a concentration selected within an interval of from 2.5 up to 30 % by weight of the air- laid blank (10); the 3D shaped product (20) is recyclable in a repulping process; at least a part of the thermoplastic polymer binder is water soluble and has a solubility of at least 1 g thermoplastic polymer binder per 100 mL water at a repulping temperature of the repulping process selected within an interval of from 20 to 100°C; the thermoplastic polymer binder is or comprises thermoplastic polymer ﬁbers selected from the group consisting of mono-component thermoplastic polymer ﬁbers, bi-component thermoplastic polymer fibers and a combination thereof; the mono-component thermoplastic polymer ﬁbers are water soluble at the repulping temperature; and at least a sheath component of the bi-component thermoplastic polymer fibers is water soluble at the repulping temperature.

2. The 3D shaped product according to claim 1, wherein the 3D shaped product (20) is repulpable in accordance with PTS-method PTS-RH 021/

3. The 3D shaped product according to claim 1 or 2, wherein any undispersed residue of the 3D shaped product (20) when sheared with water in a disintegrator for 20 min in the repulping process corresponds to less than 50 % (w/w), preferably less than 20 % (w/w), of a weight of the 3D shaped product (20).

4. The 3D shaped product according to any one of the claims 1 to 3, wherein at least a part of the thermoplastic polymer binder is water soluble at a temperature selected within an interval of from 30 to 90°C, and preferably within an interval of from 30 to 70°C.

5. The 3D shaped product according to any one of the claims 1 to 4, wherein the thermoplastic polymer binder is a thermoplastic polymer binder with a softening point not exceeding a degradation temperature of the natural fibers.

6. The 3D shaped product according to any one of claims 1 to 5, wherein the thermoplastic polymer binder is or comprises mono-component thermoplastic polymer ﬁbers made of a material selected from the group consisting of polyvinyl alcohol (PVA), polyethylene glycol (PEG), poly(2-ethyl-2-oxazoline) (PEOX), polyvinyl ether (PVE), polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMAA) and copolymers and/or mixtures thereof.

7. The 3D shaped product according to any one of claims 1 to 6, wherein the thermoplastic polymer binder is or comprises bi-component thermoplastic polymer ﬁbers comprising: a core component made of a material selected from the group consisting of polyvinyl alcohol (PVA), polyethylene glycol (PEG), poly(2-ethyl-2-oxazoline) (PEOX), polyvinyl ether (PVE), polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMMA) and copolymers and/or mixtures thereof; and a sheath component made of a material selected from the group consisting of PVA, PEG, PEOX, PVE, PVP, PAA, PMAA and copolymers and/or mixtures thereof.

8. The 3D shaped product according to any one of the claims 1 to 7, wherein the thermoplastic polymer binder is or comprises bi-component thermoplastic polymer fibers comprising: a core component made of 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) and copolymers and/or mixtures thereof; and a sheath component made of a material selected from the group consisting of polyvinyl alcohol (PVA), polyethylene glycol (PEG), poly(2-ethyl-2-oxazoline) (PEOX), polyvinyl ether (PVE), polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMAA) and copolymers and/or mixtures thereof.

9. The 3D shaped product according to any of the claims 1 to 8, wherein the thermoplastic polymer binder comprises a thermoplastic polymer powder made of a material selected from the group consisting of polyvinyl alcohol (PVA), polyethylene glycol (PEG), poly(2-ethyl-2-oxazoline) (PEOX), polyvinyl ether (PVE), polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMAA) and copolymers and/or mixtures thereof.

10. The 3D shaped product according to any one of the claims 1 to 9, wherein the natural fibers are wood fibers, preferably cellulose and/or Iignocellulose ﬁbers, and more preferably cellulose and/or lignocellulose pulp ﬁbers produced by chemical, mechanical and/or chemo-mechanical pulping of softwood and/or hardwood.

11. The 3D shaped product according to c|aim 10, wherein the natural ﬁbers are cellulose and/or lignocellulose pulp fibers in a form selected from the group consisting of sulfate pulp, sulfite pulp, thermomechanical pulp (TMP), high temperature thermomechanical pulp (HTMP), mechanical fiber intended for medium density ﬁberboard (MDF-ﬁber), chemo-thermomechanical pulp (CTMP), high temperature chemo-thermomechanical pulp (HTCTMP), and a combination thereof.

12. The 3D shaped product according to any one of claims 1 to 11, wherein the 3D shaped product (20) comprises at least one surface (21, 23) that is heat sealed to inhibit linting from the at least one surface (21, 23).

13. The 3D shaped product according to any one of claims 1 to 12, wherein the 3D shaped product (20) comprises at least one surface coated with a surface layer selected from the group consisting of a linting inhibiting layer, a moisture barrier layer, a haptic layer and a colored layer.

14. The 3D shaped product according to c|aim 13, wherein the surface layer comprises at least one substance prepared as solutions, emulsions and/or dispersions, such as a thermoplastic polymer, a natural polymer, such as starch, agar, guar gum, locust bean gum, and/or microfibrillar or nanoﬁbrillar cellulose or lignocellulose, or mixtures thereof, and is applied to the at least one surface of the 3D shaped product (20) by spraying it onto the at least one surfaces of the 3D shaped product (20) or the air-laid blank (10).

15. The 3D shaped product according to c|aim 14, wherein the surface layer is attached to the at least one surface of the 3D shaped product (20) by a water soluble hotmelt glue and/or by a water soluble adhesive film.

16. An air-laid blank (10) configured for hot pressing into a three-dimensional (3D) shaped product (20),=; air-laid blank (10) comprises: natural ﬁbers at a concentration of at least 70 % by weight of the air-laid blank (10); anda thermoplastic polymer binder at a concentration selected within an interval of from 2.5 up to 30 % by weight of the air-laid blank (10), wherein the air-laid blank (10) is recyclable in a repulping process; at least a part of the thermoplastic polymer binder is water soluble and has a solubility of at least 1 g thermoplastic polymer binder per 100 mL water at a repulping temperature of the repulping process selected within an interval of from 20 to 100°C; the thermoplastic polymer binder is or comprises thermoplastic polymer ﬁbers selected from the group consisting of mono-component thermoplastic polymer ﬁbers, bi-component thermoplastic polymer fibers and a combination thereof; the mono-component thermoplastic polymer ﬁbers are water soluble at the repulping temperature; and at least a sheath component of the bi-component thermoplastic polymer fibers is water soluble at the repulping temperature.

17. The air-laid blank according to claim 16, wherein at least a part of the thermoplastic polymer binder is water soluble at a temperature selected within an interval of from 30 to 90°C, and preferably within an interval of from 30 to 70°C.

18. The air-laid blank according to claim 16 or 17, wherein the thermoplastic polymer binder is a thermoplastic polymer binder with a softening point not exceeding a degradation temperature of the natural ﬁbers.

19. The air-laid blank according to any one of claims 16 to 18, wherein the thermoplastic polymer binder is or comprises mono-component thermoplastic polymer ﬁbers made of a material selected from the group consisting of polyvinyl alcohol (PVA), polyethylene glycol (PEG), poly(2-ethyl-2-oxazoline) (PEOX), polyvinyl ether (PVE), polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMAA) and copolymers and/or mixtures thereof.

20. The air-laid blank according to any one of claims 16 to 19, wherein the thermoplastic polymer binder is or comprises bi-component thermoplastic polymer ﬁbers comprising: a core component made of a material selected from the group consisting of polyvinyl alcohol (PVA), polyethylene glycol (PEG), poly(2-ethyl-2-oxazoline) (PEOX), polyvinyl ether (PVE),polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMAA) and copolymers and/or mixtures thereof; and a sheath component made of a material selected from the group consisting of PVA, PEG, PEOX, PVE, PVP, PAA, PMAA and copolymers and/or mixtures thereof.

21. The air-laid blank according to any one of the claims 16 to 20, wherein the thermoplastic polymer binder is or comprises bi-component thermoplastic polymer ﬁbers comprising: a core component made of 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) and copolymers and/or mixtures thereof; and a sheath component made of a material selected from the group consisting of polyvinyl alcohol (PVA), polyethylene glycol (PEG), poly(2-ethyl-2-oxazoline) (PEOX), polyvinyl ether (PVE), polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMAA) and copolymers and/or mixtures thereof.

22. The air-laid blank according to any of the claims 16 to 21, wherein the thermoplastic polymer binder comprises a thermoplastic polymer powder made of a material selected from the group consisting of polyvinyl alcohol (PVA), polyethylene glycol (PEG), poly(2-ethyl-2-oxazoline) (PEOX), polyvinyl ether (PVE), polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PMAA) and copolymers and/or mixtures thereof.

23. The air-laid blank according to any one of the claims 16 to 22, wherein the natural ﬁbers are wood fibers, preferably cellulose and/or lignocellulose ﬁbers, and more preferably cellulose and/or lignocellulose pulp ﬁbers produced by chemical, mechanical and/or chemo-mechanical pulping of softwood and/or hardwood.

24. The air-laid blank according to claim 23, wherein the natural ﬁbers are cellulose and/or lignocellulose pulp fibers in a form selected from the group consisting of sulfate pulp, sulfite pulp, thermomechanical pulp (TMP), high temperature thermomechanical pulp (HTMP), mechanical fiber intended for medium density ﬁberboard (MDF-ﬁber), chemo-thermomechanical pulp (CTMP), high temperature chemo-thermomechanical pulp (HTCTMP), and a combination thereof.

25. A method for manufacturing a three-dimensional (3D) shaped product (20), the method comprising hot pressing (S1) of a male tool (30) into an air-laid blank (10) as defined in any one of claims 16 to 24 to form a 3D shaped cavity (26) in the 3D shaped product (20).

26. A method for manufacturing a three-dimensional (3D) shaped product (20), the method comprising hot pressing (S1) an air-laid blank (10) as defined in any one of claims 16 to 24 between a male tool (30) and a female tool (50).