Recyclable 3d shaped products from air-laid blanks

Abstract

3D shaped product (20) is formed by hot pressing of an air-laid blank (10) comprising 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 in the interval 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 portion of the thermoplastic polymer binder is water-soluble at the repulping temperature of the repulping process. The 3D shaped product (20) is an environmentally friendly alternative to plastic 3D shaped products made from foamed polymers and is recyclable in existing recycling schemes.

Description

Technical Field

[0001] Embodiments of the present invention generally relate to three-dimensional (3D) shaped products, and particularly to 3D shaped products that can be recycled in a re-sizing process, as well as methods for producing such 3D shaped products and air-laid preforms. Background Technology

[0002] With growing awareness of the environment and human-induced climate change, the use of single-use plastic items and products has become increasingly questionable. However, despite these concerns, their use has increased dramatically due to new trends in lifestyles and consumer habits over the past decade. One reason for this is the increasing volume of goods shipped worldwide, requiring protection against shocks, vibrations, and / or extreme temperatures. A common way to protect goods is by including cushioning and / or insulating elements or products, such as inserts in appropriate forms within packaging. These can be made from various materials, but are typically made from expanded polystyrene (EPS), which is by far the cheapest and most common. In some cases, the entire package may be made of EPS. One example is shipping boxes used for foods that must be stored within a specified temperature range (such as cold foods like fish, or hot foods like ready-to-eat 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 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 manufactured through a process called pulp molding, in which a fiber suspension is vacuum-drawn onto a wire mold. Another technology for forming such inserts and other alternatives for different types of single-use plastic articles and products is described in U.S. Patent Application No. 2010 / 0190020, European Patent No. 1 446 286, and International Application No. 2014 / 142714. This technology involves hot-pressing porous fiber mats produced by a process called air-laid fabrication into a 3D structure using a matching rigid mold or by membrane molding.

[0004] The presence of adhesives in the methods described in U.S. Patent Application No. 2010 / 0190020, European Patent No. 1 446 286, and International Application No. 2014 / 142714 poses several challenges from a recycling perspective. The adhesives are prepared to have excellent adhesion to cellulose and / or lignocellulose fibers in the air-laid preform. They also have extremely low solubility in water. Therefore, when sheared in water during the repulping process, the adhesives prevent the 3D structure from effectively disintegrating into single pulp fibers. Furthermore, the adhesives may leave sticky impurities, commonly referred to as "stickies," in the repulping process, which severely limits the usability of the recycled pulp obtained from the repulping process. Summary of the Invention

[0005] One objective is to provide recyclable 3D-molded products and methods for manufacturing such 3D-molded products.

[0006] One specific objective is to provide this type of 3D-shaped product that can be recycled in a re-pulping process.

[0007] These and other objectives are achieved through embodiments of the present invention.

[0008] This invention is defined in the independent claims. Other embodiments of the invention are defined in the dependent claims.

[0009] One aspect of the present invention relates to a 3D-formed product. The 3D-formed product is formed by hot pressing an air-laid preform comprising at least 70% natural fibers by weight of the preform and a thermoplastic polymer binder selected at a concentration in the range of 2.5% to 30% by weight of the preform. The 3D-formed product is recyclable in a re-sizing process. At least a portion of the thermoplastic polymer binder is water-soluble at the re-sizing temperature of the re-sizing process.

[0010] Another aspect of the invention relates to an air-laid preform configured for hot pressing into a 3D-formed product. The air-laid preform comprises natural fibers at a concentration of at least 70% by weight of the preform. The preform also comprises a thermoplastic polymer binder selected at a concentration in the range of 2.5% to 30% by weight of the preform. The preform is recyclable in a re-sizing process, and at least a portion of the thermoplastic polymer binder is water-soluble at the re-sizing temperature of the re-sizing process.

[0011] Another aspect of the present invention relates to a method for manufacturing 3D molded products. The method includes hot-pressing a male tool into an air-laid blank according to the above-described method, or hot-pressing the air-laid blank according to the above-described method between a male tool and a female tool.

[0012] The 3D-molded products of this invention can be used as more environmentally friendly alternatives to corresponding 3D-molded products and plastic tableware made of polymers (e.g., expanded polystyrene). The 3D-molded products are recyclable during the re-pulping process and can therefore be recycled within existing recycling schemes. Attached Figure Description

[0013] The implementation scheme and its other objects and advantages can be best understood by referring to the following description in conjunction with the accompanying drawings, wherein:

[0014] Figure 1 This is an exemplary embodiment of the cross-section of a 3D-molded product;

[0015] Figure 2 This schematically illustrates different densities in different parts of a 3D-molded product. Figure 1 3D molded products;

[0016] Figure 3 The illustration schematically shows the hot pressing of the air-laid blank to form a cavity before the male die tool engages the air-laid blank to create the cavity. Figure 1 The 3D-formed product shown;

[0017] Figure 4 The illustration schematically shows the hot pressing of the air-laid web blank to form a web during engagement of the male die tool with the air-laid web blank. Figure 1 The 3D-formed product shown;

[0018] Figure 5 This is a schematic diagram of male and female mold tools according to one embodiment, which are configured for hot pressing an airflow web-forming preform to form a 3D molded product;

[0019] Figure 6 This is a flowchart illustrating a method for manufacturing a 3D-molded product according to one embodiment; and

[0020] Figure 7 An exemplary implementation of a 3D-molded product in the form of a spoon is shown. Detailed Implementation

[0021] Embodiments of the present invention generally relate to three-dimensional (3D) shaped products, and particularly to 3D shaped products that can be recycled in a re-sizing process, as well as methods for producing such 3D shaped products and air-laid preforms.

[0022] The 3D-molded products of this invention can be used as environmentally friendly alternatives to corresponding 3D-molded products made from conventional foamed polymers (e.g., expanded polystyrene (EPS)). More sustainable alternatives to polymer products have been proposed in U.S. Patent Application No. 2010 / 0190020, European Patent No. 1 446 286, and International Application No. 2014 / 142714, involving the use of a matching rigid mold or thermoforming of porous fiber mats (air-laid preforms) produced by a process called air-laid molding into 3D structures. However, the 3D-molded products produced in the aforementioned documents are difficult to recycle in existing recycling schemes. This is due to the presence of binders in the air-laid preforms. These binders are prepared to have excellent adhesion to the cellulose and / or lignocellulose fibers in the air-laid preforms. They also have very low solubility in water. Therefore, when sheared in water during a repulping process, the binders prevent the 3D-molded product from effectively disintegrating into single pulp fibers. In addition, binders may leave sticky impurities in the repulping process, often referred to as "adhesives," which severely limits the availability of recycled pulp obtained from the repulping process.

[0023] This invention relates to 3D-formed products that can be recycled in a repulping process. Therefore, when sheared with water in a repulping process, the 3D-formed product can be repulped into individual fibers. This means that the 3D-formed product of this invention can be recycled using existing recycling methods.

[0024] Generally, if the air-laid preform and the 3D-formed product made from it can disintegrate in an opener used for that specific purpose, then the air-laid preform and the 3D-formed product made from it can be recycled and run through the air-laid process again, possibly with the addition of additional adhesives. This is practically only possible for edge trim and other process waste that is recycled within the production facility. For consumers and other end-users, this is not an option because the air-laid process is not present in existing recycling schemes. A better option would be if the products produced by or through air-laid processes could be classified into one of the existing recycling classes (to which there are already operating collection and recycling systems). These would be the naturally existing classes collected from air-laid preforms and 3D-formed products, since most of the material is made from wood fibers that can enter the paper or paperboard manufacturing process. In the case of printing paper that is sensitive to impurities that may cause defects (failures) in the printing process or dark specifications of the paper, paperboard classes are typically a better option. Recycled paperboard is often used as the middle layer in multi-layered boxboard or as the corrugated paper in corrugated board. These are less sensitive to impurities, even those that reduce the strength of recycled materials.

[0025] One aspect of the present invention relates to a 3D-molded product 20, see [link to product description]. Figure 1 See also Figure 3 and 4 The 3D-formed product 20 is formed by hot pressing an air-laid preform 10 comprising at least 70% natural fibers by weight of the air-laid preform 10 and a thermoplastic polymer binder selected at a concentration ranging from 2.5% to 30% by weight of the air-laid preform 10. The 3D-formed product 20 is recyclable in a re-sizing process, and at least a portion of the thermoplastic polymer binder is water-soluble at the re-sizing temperature of the re-sizing process.

[0026] The 3D-formed product 20 of this embodiment is produced from an air-laid preform 10 in a hot-pressing process. The air-laid preform 10 (sometimes also referred to as a dry-laid preform, air-laid mat, dry-laid pad, air-laid web, or dry-laid web) is formed by a process called air-laid fabrication, in which natural fibers and a binder are mixed with air to form a porous fiber mixture deposited onto a carrier and solidified or bonded by heating or thermoforming. The air-laid preform 10 is characterized by being porous, exhibiting characteristics of open-cell foam, and is produced using a so-called dry-forming method, i.e., typically without the addition of water. The air-laid process was originally described in U.S. Patent No. 3,575,749. The air-laid preform 10 may be in the form produced as in the air-laid process. Alternatively, the air-laid preform 10 may be in a form that is at least partially processed, such as by cutting into a given shape prior to hot pressing.

[0027] As used herein, the hot-press indicator exposes the air-laid preform 10 to the pressure applied by pressing the male mold tool 30 or the male mold tool 30 and female mold tool 50 into the air-laid preform 10 or molding the air-laid preform 10 in a matching mold (male mold tool 30 and female mold tool 50), while simultaneously heating or exposing the air-laid preform 10 to heat, see [reference]. Figures 3 to 5 Therefore, hot pressing means pressing at a temperature above room temperature, preferably at a temperature where the thermoplastic polymer adhesive or at least a portion thereof is ductile, or, in the case of hard-pressed products, at a temperature where the thermoplastic polymer adhesive is melting.

[0028] The 3D-formed product 20 of this embodiment is recyclable in the resizing process, i.e., resizing. This is possible because at least a portion of the thermoplastic polymer binder in the air-laid preform 10 is water-soluble at the resizing temperature of the resizing process. As used herein, water solubility means that the thermoplastic polymer binder dissolves or disperses in water during the resizing process. For example, the thermoplastic polymer binder may dissolve or disperse in water at the resizing temperature of the resizing process, i.e., forming a solution or colloidal dispersion in which the thermoplastic polymer binder exists as a monomolecule and / or forms colloidal aggregates. In one embodiment, as used herein, water solubility means a solubility greater than 0.5 g thermoplastic polymer binder / 100 ml water, preferably at least 1 g thermoplastic polymer binder / 100 ml water, and more preferably at least 5 g thermoplastic polymer binder / 100 ml water, such as at least 10 g thermoplastic polymer binder / 100 ml water. Therefore, in one embodiment, at least a portion of the water-soluble thermoplastic polymer adhesive preferably has water solubility according to the above.

[0029] In paper or paperboard processes, "repulpingability" and "recyclability" are most widely tested using the PTS method, PTS-RH 021 / 97, from the German Papiertechnische Stiftung. For paperboard products, the PTS method tests recyclability in two steps, with the first step being a repulpingability test. In the repulpingability test, 50g of material is disintegrated for 20 minutes in a standard disintegrator under the conditions specified in PTS-RH 021 / 97. Undispersed residue is screened out and its weight is measured. If the weight of the undispersed residue corresponds to less than 20% of the initial weight (50g), the material is classified as "recyclable." If the weight of the undispersed residue is 20-50% of the initial weight, the material is classified as "recyclable but warrants product design improvement."

[0030] More specifically, the PTS method, PTS-RH 021 / 97, involves disintegrating the sample according to DIN EN ISO 5263-1:2004-12, but using tap water at 40°C. Diluent is poured onto the sample material, which is placed in a disintegrator (the standard disintegrator of DIN EN ISO 5263-1:2004-12) without pre-swelling. The sample material is disintegrated to a consistency of 2.5% od, corresponding to a weighing of 50 g od and a slurry volume of 2 L. The disintegration period is 20 minutes (60,000 rpm). After disintegration, the slurry (total stock solution) is completely transferred to a standard dispenser (the standard dispenser of ZELLCHEMING Technical Information Sheet ZM V / 6 / 61) and diluted with tap water to a total volume of 10 L, corresponding to a consistency of 0.5%. Screening was performed according to ZELLCHEMING Technical Information Sheet ZM V / 18 / 62, using a perforated plate with a 0.7 mm pore size. The test apparatus was set to "low stroke" mode. A test portion (400 ml) corresponding to 2 g od of slurry was removed from the dispenser and diluted to a total volume of 1000 ml. This was then filled into the sieve over a period of 30 seconds and sieved for 5 minutes at a wash water pressure of 0.3 bar. After 5 minutes, the water supply and membrane displacement motor were shut off. The valve on the retainer was opened to drain the water that had accumulated below the test chamber. The locking screw was loosened and the test chamber was tilted upwards. The rear nozzle was covered with one hand to prevent water droplets from falling onto the unprotected perforated plate with residue on it. The residue from the perforated plate was washed into a 2 L tank and dehydrated through a filter inserted into a Buchner funnel. The filter was folded once and placed in a desiccator to dry at 105°C to constant weight. If the disintegration residue is no more than 20% of the input, the product is rated as "recyclable". However, if the disintegration residue is between 20% and 50% of the input, it is rated as "recyclable but warrants product design improvement".

[0031] Part II of PTS Method PTS-RH 021 / 97 for paperboard products tests for impurities, particularly substances that become extremely sticky when heated to 130°C during testing. In paperboard manufacturing processes, such sticky or tacky substances can adhere to machine fabrics and other essential components of the paperboard machine, causing operational problems and requiring extended, costly cleaning downtime. In the paper and paperboard industry, this type of impurity is commonly referred to as "adhesive." The presence of such adhesive in an unscreened, disintegrating sample classifies the material as "not recyclable due to adhesive." The presence of other impurities may limit the availability of recycled pulp from the material but is not considered entirely harmful.

[0032] Therefore, in one embodiment, the 3D-formed product 20 may be re-slurryed according to PTS-method PTS-RH 021 / 97. For example, the weight of any undispersed residue of the 3D-formed product 20 corresponds to less than 50% (weight / weight), preferably less than 20% (weight / weight), of the weight of the 3D-formed product 20 when water-sheared in a disintegrator for 20 minutes during the re-slurrying process. Thus, in one specific embodiment, after disintegrating 50g of air-laid preform 10 or 3D-formed product 20 in a standard disintegrator for 20 minutes under the conditions specified in PTS-method PTS-RH 021 / 97, the air-laid preform 10 and preferably the 3D-formed product 20 result in less than 50% (weight / weight), preferably less than 20% (weight / weight), of undispersed residue.

[0033] The repulping temperature used in the repulping process is typically in the range of 20°C to 100°C, such as in the range of 30°C to 90°C, and typically in the range of 30°C to 70°C. Therefore, in one embodiment, at least a portion of the thermoplastic polymer adhesive is water-soluble at a temperature selected from the range of 20°C to 100°C, preferably in the range of 30°C to 90°C, and more preferably in the range of 30°C to 70°C. In one specific embodiment, according to PTS-method PTS-RH 021 / 97, the temperature of the water used in the repulping process is about 40°C. Therefore, in one embodiment, at least a portion of the thermoplastic polymer adhesive is water-soluble at 40°C.

[0034] In one embodiment, the natural fiber is wood fiber. In a specific embodiment, the natural fiber is cellulose and / or lignocellulose fiber. Thus, in one embodiment, the natural fiber contains cellulose, such as in the form of cellulose and / or lignocellulose (i.e., a mixture of cellulose and lignin). The natural fiber may also contain lignin, such as in the form of lignocellulose. The natural fiber may additionally contain hemicellulose. In a specific embodiment, the natural fiber is cellulose and / or lignocellulose pulp fiber produced by chemical, mechanical, and / or chemimechanical pulping of softwood and / or hardwood. For example, the cellulose and / or lignocellulose pulp fiber is selected from the following forms: sulfate pulp, sulfite pulp, thermomechanical pulp (TMP), high-temperature thermomechanical pulp (HTMP), mechanical fiber (MDF-fiber) intended for use in medium-density fiberboard, chemimechanical pulp (CTMP), high-temperature chemimechanical pulp (HTCTMP), and combinations thereof.

[0035] Natural fibers can also be produced through other pulping methods and / or from other cellulosic or lignocellulosic raw materials such as flax, jute, hemp, kenaf, bagasse, cotton, bamboo, straw, or rice husks.

[0036] The air-laid preform 10 contains at least 70% natural fibers by weight of the air-laid preform 10. In a preferred embodiment, the air-laid preform 10 contains at least 72.5% natural fibers by weight of the air-laid preform 10, more preferably at least 75%, such as at least 77.5%, at least 80%, at least 82.5%, or at least 85%. 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 air-laid preform 10.

[0037] A thermoplastic polymer binder is included as an adhesive in the air-laid preform 10 to bond the air-laid preform 10 together and maintain its shape and structure during use, handling, and storage. The thermoplastic polymer binder may also contribute to the formation of a foam-like structure in the air-laid preform 10. The thermoplastic polymer binder entangles with natural fibers during the air-laid process to form a fiber mixture. The thermoplastic polymer binder can be added in powder form, but is more commonly added in fibrous form entangled with natural fibers during the air-laid process. Alternatively or additionally, the thermoplastic polymer binder may be added as a solution, emulsion, or dispersion to and on the air-laid preform 10 during the air-laid process. The latter technique is best suited for thin air-laid preforms 10.

[0038] In one embodiment, the thermoplastic polymer binder is selected from thermoplastic polymer powder, thermoplastic polymer fiber, and combinations thereof.

[0039] In one embodiment, the thermoplastic polymer adhesive, or at least a portion thereof, has a softening point or melting point that does not exceed the degradation temperature of the natural fibers. Therefore, the thermoplastic polymer adhesive, or at least a portion thereof, softens or melts at a processing temperature that does not exceed the degradation temperature of the natural fibers during hot pressing. This means that the thermoplastic polymer adhesive becomes malleable or meltable at a temperature that does not degrade the natural fibers in the air-laid preform 10.

[0040] In one embodiment, the thermoplastic polymer binder is preferably polar to promote solubility in water during the repulping process. The polar thermoplastic polymer binder also exhibits good adhesion to cellulose and / or lignocellulose fibers (i.e., the natural fibers of the air-laid preform 10).

[0041] In one embodiment, the thermoplastic polymer binder is or comprises one-component and / or two-component thermoplastic polymer fibers. Two-component 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 mixture, and the sheath is made of a second, different polymer, copolymer, and / or polymer mixture. In such an embodiment, the one-component thermoplastic polymer fiber is water-soluble at the resizing temperature. Accordingly, at least the sheath component of the two-component thermoplastic polymer fiber is water-soluble at the resizing temperature. In another embodiment, both the sheath component and the core component of the two-component thermoplastic polymer fiber are water-soluble at the resizing temperature.

[0042] In one embodiment, the thermoplastic polymer binder is or comprises a bicomponent polymer fiber, such as a bicomponent polymer fiber comprising a core component made of a material having a melt temperature higher than the temperature at which the air-laid preform 10 is heated during hot pressing. The bicomponent polymer fiber also comprises a sheath component made of a material having a melt temperature lower than the temperature at which the air-laid preform 10 is heated during hot pressing.

[0043] In this embodiment, the melt temperature of the core component of the bicomponent polymer fiber is higher than that of the sheath component. Furthermore, the melt temperature of the core component is higher than the processing temperature at which the air-laid preform is heated during hot pressing, while the melt temperature of the sheath component is lower. This means that the core component does not melt but advantageously becomes ductile during hot pressing, while the sheath component melts or at least significantly thickens. Therefore, the sheath component adheres to the natural fibers, while the unmelted but ductile core component provides structural support. This bicomponent polymer fiber achieves good adhesion to the natural fibers and simultaneously maintains the porous structure of the air-laid preform, even during hot pressing.

[0044] Examples of water-soluble thermoplastic 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), copolymers thereof, and mixtures thereof.

[0045] In one embodiment, the thermoplastic polymer adhesive is or comprises a single-component thermoplastic polymer fiber, such as a single-component thermoplastic polymer fiber made of: i) a material selected from PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, copolymers thereof and mixtures thereof, and ii) optionally one or more additives.

[0046] Therefore, in one embodiment, the thermoplastic polymer fiber 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, plus one or more additives.

[0047] In another embodiment, the thermoplastic polymer binder is or comprises a bicomponent thermoplastic polymer fiber, such as a bicomponent thermoplastic polymer fiber having a sheath or sheath and core made of: i) one or more materials selected from PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, copolymers thereof, and mixtures thereof, and ii) optionally one or more additives. In one specific embodiment, at least the sheath of the bicomponent thermoplastic polymer fiber is made of: i) a material selected from PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, copolymers thereof, and mixtures thereof, and ii) optionally one or more additives. In such a specific embodiment, the core of the bicomponent thermoplastic polymer fiber may also be selected from this group. However, if the core of the bicomponent thermoplastic polymer fiber does not soften in hot pressing to become sticky and adhere to the natural fiber, the core may actually be made of a material that is not necessarily water-soluble at the repulping temperature. This means that the core may be made of a thermoplastic polymer that is not necessarily water-soluble at the repulping temperature. Therefore, in this specific embodiment, the bicomponent thermoplastic polymer fiber comprises a core component made of: i) a material selected from polyethylene (PE), ethylene acrylate 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; and a sheath component made of: i) a material selected from PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, copolymers thereof, and mixtures thereof, and ii) optionally one or more additives.In another embodiment, the thermoplastic polymer adhesive is or comprises (e.g., composed of) the following: a single-component thermoplastic polymer fiber made of: i) a material selected from PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, copolymers thereof, and mixtures thereof, and ii) optionally one or more additives; a two-component thermoplastic polymer fiber having a core and sheath made of: i) a material selected from PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, copolymers thereof, and mixtures thereof, and ii) optionally one or more additives; and / or a two-component thermoplastic polymer fiber having a sheath made of: i) a material selected from PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, copolymers thereof, and mixtures thereof, and ii) optionally one or more additives, and a core made of: i) a material selected from PE, EAA, EVA, PP, PS, PBAT, PBS. Materials of PLA, PET, PCL, their copolymers and mixtures thereof, and ii) optionally one or more additives.

[0048] Thermoplastic polymer adhesives can be made from a single type of thermoplastic polymer fiber, i.e., from the same material in the case of single-component thermoplastic polymer fibers, or from the same one or more materials in the case of two-component thermoplastic polymer fibers. However, thermoplastic polymer adhesives made from one or more (i.e., at least two) different single-component thermoplastic polymer fibers made from different materials and / or one or more different two-component thermoplastic polymer fibers made from different materials can also be used.

[0049] In one embodiment, the thermoplastic polymer binder is or comprises a thermoplastic polymer powder made from: i) a material selected from PVA, PEG, PEOX, PVE, PVP, PAA, PMAA, copolymers thereof, and mixtures thereof, and ii) optionally one or more additives.

[0050] As mentioned earlier, thermoplastic polymer adhesives, which are combinations of thermoplastic polymer fibers and thermoplastic polymer powders, can also be used.

[0051] The primary component of the thermoplastic polymer binder in the air-laid preform 10 is water-soluble. However, the air-laid preform 10 may contain some water-insoluble thermoplastic polymers at the resizing temperature of the resizing process, provided that the 3D-formed product 20 can be resizing, as per PTS-method PTS-RH021 / 97. Therefore, the thermoplastic polymer binder may be a mixture of a water-soluble thermoplastic polymer and a water-insoluble thermoplastic polymer at the resizing temperature of the resizing process, provided that the 3D-formed product 20 can be resizing.

[0052] In one embodiment, the thermoplastic polymer adhesive is water-soluble.

[0053] In one embodiment, the air-laid preform 10 comprises a thermoplastic polymer binder selected at a concentration ranging from 2.5% to 30% by weight of the air-laid preform 10. In some applications, a relatively low concentration of thermoplastic polymer binder may be desirable, such as 2.5% to 15% by weight of the air-laid preform 10, preferably 4% to 15% by weight, or 5% to 15% by weight, such as 7.5% to 15% by weight, and more preferably 10% to 15% by weight. In other applications, a higher concentration of thermoplastic polymer binder may be advantageous, such as 10% to 30% by weight of the air-laid preform 10, for example, 15% to 30%. In one specific embodiment, the air-laid preform 10 comprises more than 15% by weight but not more than 30% by weight of thermoplastic polymer binder. For example, the air-laid preform 10 contains a thermoplastic polymer binder selected at a concentration in the range of 15 or 17.5% to up to 30% by weight of the air-laid preform 10. In one specific embodiment, the air-laid preform 10 contains a thermoplastic polymer binder selected at a concentration in the range of 15 or 17.5% to up to 25% by weight of the air-laid preform 10, such as 20% to up to 25%. 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 air-laid preform 10, so as to maintain the porosity and foam-like structure of the air-laid preform 10 even when the air-laid preform 10 is pressed at lower pressures to obtain a porous 3D molded product 20. Generally speaking, when the air-laid preform 10 is subjected to a pressure equal to or greater than 1 MPa during hot pressing, a lower concentration of thermoplastic polymer adhesive can be used. However, if the air-laid preform 10 is not subjected to hard pressing and compaction to a high density during hot pressing, a relatively higher concentration of thermoplastic polymer adhesive is required.

[0054] In one embodiment, the 3D-formed product 20 is configured to protect packaged goods from electrostatic discharge (ESD). In such an embodiment, the air-laid preform 10 is conductive or semi-conductive. For example, the air-laid preform 10 may contain conductive polymers or conductive fibers to make the air-laid preform 10, and thus the 3D-formed product 20 formed by hot-pressing the air-laid preform 10, conductive or semi-conductive. In this case, the air-laid preform 10 preferably contains conductive polymers or fibers at a concentration not exceeding 10% by weight of the air-laid preform 10, and more preferably not exceeding 5% by weight of the air-laid preform 10. In one embodiment, a portion of the natural fibers may be replaced with conductive polymers or fibers. In another embodiment, the adhesive is made of or contains conductive polymers. In another embodiment, both embodiments are combined. In one specific embodiment, the conductive polymer or fiber is carbon fiber. Instead of or as a supplement to having conductive polymers or fibers, the air-laid preform 10 may contain conductive or semi-conductive fillers, such as carbon black, which may be, for example, in the form of an additive to the adhesive.

[0055] Therefore, in addition to natural fibers and thermoplastic polymer binders, the air-laid preform 10 may also contain one or more additives. One or more additives may be added to the thermoplastic polymer binder and / or added during the production of the thermoplastic polymer binder. Alternatively or additionally, one or more additives may be added to the natural fibers. Alternatively or additionally, one or more additives may be added to both the natural fibers and the thermoplastic polymer binder, such as during the air-laid process.

[0056] Exemplary but non-limiting examples of such additives include conductive or semi-conductive fillers, coupling agents, flame retardants, dyes, impact modifiers, etc.

[0057] In some applications, it may be desirable to seal some or all of the surfaces of the 3D-molded product 20, such as by heating, to prevent linting from one or more surfaces onto the packaged goods. Surfaces that have undergone heat treatment during hot pressing will be sealed, and no additional (heat) seal is required. At least one surface to be sealed can be sealed, such as by heating, before or after the hot pressing operation. Thus, in one embodiment, the 3D-molded product 20 includes at least one surface 21, 23, which is heat-sealed to inhibit linting from at least one surface 21, 23. Figure 1A 3D-formed product 20 is shown, having an upper surface 22, a bottom surface 24, and two end surfaces 21, 23. During hot pressing, a 3D-forming cavity 26 is formed in the upper surface 22, thereby imparting a 3D shape to the 3D-formed product 20. The end surfaces 21, 23 may then be unprocessed from the air-laid preform 10, or they may be produced by sawing, cutting, or punching the air-laid preform 10 to create these end surfaces 21, 23. In this case, it may be preferable to heat-seal these surfaces 21, 23 to prevent or at least inhibit or suppress defleasing. The upper surface 22, or at least a portion thereof, has already been hot-pressed, and therefore typically does not require heat sealing. The heat sealing of the bottom surface 24 may be applied depending on whether the bottom surface of the air-laid preform 10 has been exposed to any heat during hot pressing.

[0058] In some applications, the 3D-formed product 20, or at least a portion thereof, may be laminated with a surface layer such as a thermoplastic polymer film or nonwoven textile. This prevents linting and adds additional functionality to the surface, such as moisture resistance, tactile properties, color, and design. The film or nonwoven textile can be made of any common thermoplastic polymer. However, the film or nonwoven textile should be dissolved or peeled off from the 3D-formed product 20 during a resizing process, thereby being removed during the resizing process. Examples include the thermoplastic polymer materials previously mentioned as thermoplastic polymer adhesives. The layer may be thermally laminated onto the air-laid preform 10 by semi-melting or water-soluble hot melt adhesive and / or by direct application, such as by extrusion, onto the air-laid preform 10 or the 3D-formed product 20. In one embodiment, the film laminated to at least one surface or a portion thereof of the 3D-formed product 20 is conductive or semi-conductive to provide ESD protection for packaged goods.

[0059] In one embodiment, the surface layer is attached to at least one surface of the 3D-molded product 20 by means of a water-soluble hot melt adhesive and / or by means of a water-soluble adhesive film.

[0060] In another embodiment, the surface layer can be applied by spraying it onto one or more surfaces of the 3D-formed product 20 or the air-formed preform 10. This layer may contain any substance 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 may contain other substances that provide additional functionality to the surface layer and the 3D-formed product 20, such as emulsifiers, stabilizers, conductive agents, etc.

[0061] The 3D-molded product 20 of the implementation scheme can serve as an environmentally friendly alternative to disposable articles and products traditionally made of plastic. For example, the 3D-molded product 20 can be manufactured into cups, trays, bowls, or beakers for packaging or containing food. The recyclable 3D-molded product 20 can also be in the form of recyclable disposable tableware, including, for example, knives, forks, spoons, and stirrers. Figure 7 The illustration shows that in these cases, hot pressing is performed at relatively high pressures to increase the density of the 3D-formed product 20 to about 10 to 50 times the density of the air-blown preform 10, thereby achieving complete material solidification. As further described herein, these high pressures are preferably equal to or higher than 1 MPa, such as equal to or higher than 5 MPa, preferably equal to or higher than 10 MPa, such as equal to or higher than 15 MPa, or equal to or higher than 20 MPa. Figure 7 As shown, the 3D-formed product 20 obtained by hot-pressing the preform 10 under such high pressure typically has a strength of at least 500 kg / m³. 3 For example, at least 600 kg / m 3 Or 700kg / m 3 Preferably at least 750 kg / m 3 Or even higher, such as at least 800 kg / m 3 Or even at least 1000 kg / m 3 The average density.

[0062] The 3D-formed product 20 can be in the form of a 3D-formed packaging product 20 for cushioning and / or thermal insulation of goods, such as inserts suitable for packaging and protecting goods. In these applications, the 3D-formed product 20 preferably retains at least a portion of the porosity and open-cell foam structure of the air-laid preform 10 even after hot pressing, and thus has excellent shock absorption and thermal insulation properties. Therefore, the 3D-formed product 20 can be manufactured with a geometry suitable for protecting goods during transport and / or storage, i.e., a 3D shape. Retaining the porous characteristics of the air-laid preform starting material means that the 3D-formed product 20 can be used not only to protect consumer goods and products, but also to protect heavy equipment from impacts. Furthermore, the porous 3D-formed product 20 has improved thermal insulation properties compared to a tight and dense 3D-formed product with a thin cross-section. This means that the 3D-formed product can also, or alternatively, be used for storing and / or transporting goods that need to be kept cold, such as cold provisions, or goods that need to be kept hot or warm, such as ready-to-eat meals.

[0063] In such an embodiment, a relatively low average pressure is used during hot pressing compared to that described above for hard-pressed air-laid blank 10. As further illustrated herein, the air-laid blank 10 is preferably hot-pressed at an average pressure equal to or less than 200 kPa, such as equal to or less than 175 kPa, or preferably equal to or less than 150 kPa. In one embodiment, the average pressure is defined as the force applied during hot pressing divided by the area of ​​the air-laid blank 10.

[0064] The 3D-formed product 20 obtained by hot pressing the air-laid preform 10 under such low average pressure typically has a strength of 15 to 240 kg / m³. 3 Density within the specified range. In a preferred embodiment, the density of the 3D-molded product 20 is selected to be between 15 and 200 kg / m³. 3 Within the range of 15 to 150 kg / m 3 Within the range, and more preferably between 15 and 100 kg / m 3 Within this range. In one specific implementation, the density of the 3D-molded product 20 is selected to be between 20 and 75 kg / m³. 3 Within the range, preferably between 25 and 70 kg / m 3 Within the range, and more preferably between 25 and 65 kg / m 3 Within the range.

[0065] In one embodiment, the density of the 3D-formed product 20 is less than four times the density of the air-laid preform 10.

[0066] The 3D-formed product 20 of these embodiments is produced in a hot-pressing process from an air-laid preform 10, which retains at least some of the porosity of the air-laid preform 10. Therefore, the density of the 3D-formed product 20 is less than four times the density of the air-laid preform 10. Existing hot-pressing processes for producing dense 3D-formed products with thin cross-sections typically increase the density of the 3D-formed product to tens of times, such as 10 to 50 times, the density of the air-laid preform. This significant increase in density of existing 3D-formed products implies a substantial loss of porosity in the air-laid preform, resulting in a dense and compact fibrous structure. In stark contrast, the relatively low density increase according to these embodiments also preserves the porous structure of the air-laid preform 10 in the formed 3D-formed product 20.

[0067] As used herein, the density of the 3D-molded product 20 is the average or average density of the 3D-molded product 20. This means that the 3D-molded product 20 may contain portions or parts 25A, 25B, 25C, 25D, 25E ​​with different porosities and thus different densities, see [reference]. Figure 2This is due to the shape of the male mold tool 30 used in hot pressing, which results in different levels or amounts of hot pressing on different parts of the air-blown blank 10. See [link to relevant documentation]. Figure 3 and 4 The different densities in different parts 25A, 25B, 25C, 25D, and 25E of the 3D molded product 20 Figure 2 The images are schematically shown in different grayscale modes. For example, the portion of the air-laid preform 10 aligned with the protruding structure 32 of the male mold tool 30 is pressed and compacted more rigidly than other portions of the air-laid preform 10. Therefore, parts 25C, 25E ​​of the 3D-formed product 20 aligned with the protruding structure 32 of the male mold tool 30 will have a higher density compared to other portions 25A, 25B, 25D of the 3D-formed product 20. However, the density of the 3D-formed product 20 is an average or average density, not the density of its different portions, and represents the total mass of the 3D-formed product 20 divided by the volume of the 3D-formed product 20 (excluding any cavities 26 formed during hot pressing by the male mold tool 30 and / or female mold tool 50), see [link to relevant documentation]. Figure 5 .

[0068] In one embodiment, the density of the 3D-formed product 20 is equal to or less than three times the density of the air-laid preform 10. In a specific embodiment, the density of the 3D-formed product 20 is equal to or less than twice the density of the air-laid preform 10.

[0069] Therefore, according to the present invention, the density of the 3D molded product 20 increases by no more than 300%, preferably no more than 250%, and more preferably no more than 200%, 150%, or most preferably no more than 100%, compared with the density of the air-laid preform 10.

[0070] However, since the male mold tool 30 or both the male mold tool 30 and the female mold tool 50 are hot-pressed into the air-laid preform 10, the hot pressing preferably results in an increase in the density of the 3D-formed product 20 compared to the density of the air-laid preform 10. The density increase due to 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%.

[0071] In various embodiments, the density increase due to hot pressing is at least 12.5% ​​but not more than 300%, such as at least 15% but not more than 275%, at least 17.5% but not more than 250%, at least 20% but not more than 225%, such as at least 22.5% but not more than 200%.

[0072] In one embodiment, the density of the air-blown blank 10 is selected to be between 10 and 60 kg / m³. 3 Within the range.

[0073] In one embodiment, the thickness of the air-laid preform 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 air-laid preform 10 is at least 100 mm, such as at least 150 mm, at least 200 mm, or at least 250 mm. Very thick air-laid preforms 10, with a thickness of at least 300 mm, are also possible. Thus, such embodiments use considerably thick air-laid preforms 10 to obtain 3D-formed products 20 suitable for cushioning and / or thermal insulation, even after hot pressing. The thickness of the air-laid preform 10 can be selected based on the specific application of the resulting 3D-formed product 20, such as based on the cushioning and / or isolation requirements of the 3D-formed product 20 and / or based on the geometry of the packaged goods to be protected by the 3D-formed product 20.

[0074] Accordingly, the thickness of the 3D-formed product 20 may be at least 10 mm, preferably at least 15 mm, such as at least 20 mm or at least 25 mm, and more preferably at least 30 mm, such as at least 35 mm, or at least 40 mm, or even thicker, such as at least 45 mm or at least 50 mm. In one embodiment, when the air-laid preform 10 is hot-pressed into the 3D-formed product 20, a low average pressure, such as equal to or less than 200 kPa, is used. This low average pressure maintains most of the thickness of the air-laid preform 10. The hot pressing of the air-laid preform 10 can hard-press different portions of the air-laid preform 10. Therefore, the thickness of some portions of the 3D-formed product 20 may be substantially the same as or only slightly less than the thickness of the air-laid preform 10. In one specific embodiment, at least those portions of the 3D-formed product 20 that come into contact with the goods to be protected preferably have the thicknesses mentioned above.

[0075] Another aspect of the invention relates to an air-laid preform 10 configured for hot pressing into a 3D molded product 20. The air-laid preform 10 comprises natural fibers at a concentration of at least 70% by weight of the air-laid preform 10. The air-laid preform 10 also comprises a thermoplastic polymer binder selected at a concentration in the range of 2.5% to 30% by weight of the air-laid preform 10. The air-laid preform 10 is recyclable in a re-sizing process, and at least a portion of the thermoplastic polymer binder is water-soluble at the re-sizing temperature of the re-sizing process.

[0076] The above disclosures regarding various embodiments of thermoplastic polymer binders and natural fibers discussed in conjunction with 3D molded product 20 are also applicable to air-laid preform 10 of the present invention.

[0077] Another aspect of the implementation scheme relates to a method for manufacturing a 3D-molded product 20, see [link to implementation details]. Figures 3 to 6 The method includes hot-pressing a male mold tool 30 into an air-laid blank 10 according to the invention in step S1 to form a 3D molded product 20.

[0078] In one implementation scheme Figure 6 Step S1 involves hot-pressing a heated male die tool 30 into the air-laid preform 10. In this embodiment, the heated male die tool 30 is preferably heated to a temperature selected in the range of 120°C to 210°C, and more preferably in the range of 120°C to 190°C. Therefore, in this embodiment, heating of the air-laid preform 10 is achieved using a heated male die tool 30. The male die tool 30 may include heating elements 38, which are preferably controllable heating elements 38 to heat the male die tool 30 to the desired temperature for hot pressing. The temperature of the male die tool 30 typically depends on the type of natural fibers and thermoplastic polymer binder in the air-laid preform 10 and the cycle time of the hot pressing in step S1. However, the ranges presented above are suitable for most combinations of natural fibers, thermoplastic polymer binders, and cycle times.

[0079] In one embodiment, the air-blown blank 10 is positioned on the base pressure plate 40, such as... Figure 3 and 4 As shown. In one implementation, Figure 6 Step S1 includes hot-pressing a heated male mold tool 30 into an air-laid blank 10 positioned on a base plate 40 having a temperature equal to or lower than the ambient temperature.

[0080] In these embodiments, heating of the air-laid preform 10 is achieved via the male mold tool 30, while the base platen 40 is at ambient temperature, typically room temperature, or may even be cooled. Keeping the base platen 40 at ambient temperature or even cooled reduces the risk of overheating the air-laid preform 10 during hot pressing in step S1, which could otherwise have negative consequences such as degradation of natural fibers, molten thermoplastic polymer binders, and disruption of the porous structure of the air-laid preform 10 and the resulting 3D molded product 20.

[0081] However, during the hot pressing in step S1, even when combined with the heated male mold tool 30, the airflow web-forming blank 10 can be positioned on the heated base platen 40. In this case, during the hot pressing, the lower side of the airflow web-forming blank 10 facing the heated base platen 40 will also be heat-sealed.

[0082] In another implementation scheme, see Figure 5 Step S1 includes hot-pressing a heated male mold tool 30 and a heated female mold tool 50 into an airflow web-forming preform 10 positioned between the heated male mold tool 30 and the heated female mold tool 50 to form a 3D-formed product 20 having a 3D shape at least partially defined by the male mold tool 30 and the female mold tool 50. In one embodiment, the male mold tool 30 forms a 3D forming cavity 26 in the formed 3D-formed product 20, while the female mold tool 50 includes a 3D shape defining the external geometry of the 3D-formed product 20 and the 3D forming cavity 56.

[0083] Matching male and female mold tools 30 can also be used similarly to molds during hot pressing to form 3D molded products 20, such as tableware or other product forms, which, for most parts, have a thin and solidified cross-section. In this case, the airflow web preform 10 is positioned between the male mold tool 30 and the female mold tool 50 during hot pressing to form a 3D molded product 20 having a 3D shape at least partially defined by the male mold tool 30 and the female mold tool 50.

[0084] In one embodiment, both the male mold tool 30 and the female mold tool 50 are heated to a temperature preferably selected within the range of 120°C to 210°C, and more preferably within the range of 120°C to 190°C. The male mold tool 30 and the female mold tool 50 may be heated to the same temperature or different temperatures. In another embodiment, one of the male mold tool 30 and the female mold tool 50 is heated while the other is at ambient temperature.

[0085] In the embodiments presented above, at least one of the tools 30, 50 used in the hot pressing in step S1 is heated. In another embodiment, the method includes... Figure 6 In step S1, at least a portion of the airflow web forming blank 10 is heated before hot pressing the male mold tool 30 into the airflow web forming blank 10 or before pressing or molding the airflow web forming blank 10 between the male mold tool 30 and the female mold tool 50.

[0086] Therefore, heating the air-laid preform 10, rather than heating the male mold tool 30 and / or any female mold tool 50, is preferably performed before the hot pressing operation. Then, the air-laid preform 10 is preferably heated to a temperature at which the thermoplastic polymer adhesive or at least a portion thereof is in a malleable but unmelted state. For most thermoplastic polymer adhesives, 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 air-laid preform 10 is preferably heated to a temperature in the range of 80°C to 180°C.

[0087] In this embodiment, the male mold tool 30 and the base platen 40 or the female mold tool 50 can be independently exposed to ambient temperature (such as room temperature) or cooled.

[0088] In one embodiment, heating of the airflow web blank 10 can be combined with the use of a heated male mold tool 30 or at least one of the heated male mold tool 30 and female mold tool 50.

[0089] In some applications, especially for hard-pressed products, the air-laid blank 10 needs to be dried, for example, by heating, before hot pressing. In this case, the air-laid blank 10 can be heated before hot pressing, and then further heated by heated tools 30, 50 during the hot pressing operation.

[0090] In one embodiment, the overall 3D shape of the 3D-molded product 20 is defined at least in part by a male mold tool 30 that sometimes forms at least one cavity 26 within the 3D-molded product 20 and by an optional female mold tool 50 that at least partially defines the external shape of the 3D-molded product 20. The 3D shape and geometry of the 3D-molded product 20 are selected at least in part based on the shape of the packaged goods to be protected by the 3D-molded product 20 or by the intended use of the 3D-molded product 20 (e.g., the form of a food container).

[0091] In one embodiment, step S1 includes hot-pressing the male die tool 30 into the air-laid blank 10 at an average pressure equal to or less than 200 kPa. In a specific embodiment, the male die tool 30 is hot-pressed into the air-laid blank 10 at a pressure equal to or less than 175 kPa, and more preferably equal to or less than 150 kPa. In embodiments where the air-laid blank 10 is hard-pressed between the male die tool 30 and the female die tool 50, a pressure higher than 1 MPa can be used, including higher than 5 MPa, higher than 10 MPa, higher than 15 MPa, or even higher than 20 MPa.

[0092] The method may also include an additional step of cutting the air-blown preform 10 and / or the 3D-formed product 20 into the desired shape, such as by sawing, cutting, or stamping. This cutting operation may be performed before, during, and / or after hot pressing.

[0093] In one implementation scheme Figure 6 Step S1 is performed without water. Therefore, no water is added during the hot pressing operation. The air-laid blank 10 is preferably at environmental equilibrium moisture content or can be dried.

[0094] The above description and Figure 6 The method shown is suitable for forming a 3D molded product 20 according to the present invention.

[0095] The above embodiments should be understood as several exemplary examples of the present invention. Those skilled in the art will understand that various modifications, combinations, and changes can be made to the embodiments without departing from the scope of the present invention. In particular, where technically possible, different portions of solutions from different embodiments can be combined in other configurations.

Claims

1. Three-dimensional (3D) molded products (20), of which A three-dimensional (3D) molded product (20) is formed by hot pressing an air-laid preform (10) comprising at least 70% natural fibers by weight of the air-laid preform (10) and a thermoplastic polymer binder selected in the range of 2.5% to 30% by weight of the air-laid preform (10); The three-dimensional (3D) molded product (20) is recyclable in the re-pulping process; and At least a portion of the thermoplastic polymer adhesive is water-soluble at the re-pulping temperature of the re-pulping process. in The thermoplastic polymer adhesive comprises thermoplastic polymer fibers, which are selected from single-component thermoplastic polymer fibers, two-component thermoplastic polymer fibers, or combinations thereof; The one-component thermoplastic polymer fiber is water-soluble at the repulping temperature, and the one-component thermoplastic polymer fiber has a solubility greater than 0.5 g thermoplastic polymer binder / 100 ml water; and At least the sheath component of the bicomponent thermoplastic polymer fiber is water-soluble at the repulping temperature, and the sheath component of the bicomponent thermoplastic polymer fiber has a solubility greater than 0.5 g thermoplastic polymer binder / 100 ml water. The repulping temperature is in the range of 20°C to 100°C.

2. The three-dimensional (3D) molded product according to claim 1, wherein the three-dimensional (3D) molded product (20) can be re-slurryed according to PTS-method PTS-RH 021 / 97.

3. The three-dimensional (3D) molded product according to claim 1 or 2, wherein any undispersed residue of the three-dimensional (3D) molded product (20) corresponds to less than 50% of the weight of the three-dimensional (3D) molded product (20) when it is water-sheared for 20 minutes in a disintegrator during the repulping process.

4. The three-dimensional (3D) molded product according to claim 3, wherein any undispersed residue of the three-dimensional (3D) molded product (20) corresponds to less than 20% of the weight of the three-dimensional (3D) molded product (20) when it is water-sheared for 20 minutes in a disintegrator during the repulping process.

5. The three-dimensional (3D) molded product according to claim 1 or 2, wherein at least a portion of the thermoplastic polymer adhesive is water-soluble at a temperature selected from the range of 20°C to 100°C.

6. The three-dimensional (3D) molded product according to claim 1 or 2, wherein at least a portion of the thermoplastic polymer adhesive is water-soluble at a temperature selected from the range of 30°C to 90°C.

7. The three-dimensional (3D) molded product according to claim 1 or 2, wherein at least a portion of the thermoplastic polymer adhesive is water-soluble at a temperature selected from the range of 30°C to 70°C.

8. The three-dimensional (3D) molded product according to claim 1 or 2, wherein at least a portion of the thermoplastic polymer adhesive has a softening point not exceeding the degradation temperature of the natural fiber.

9. The three-dimensional (3D) molded product according to claim 1 or 2, wherein the thermoplastic polymer adhesive has a softening point not exceeding the degradation temperature of the natural fiber.

10. The three-dimensional (3D) molded product according to claim 1 or 2, wherein The thermoplastic polymer adhesive is a thermoplastic polymer fiber, which is selected from single-component thermoplastic polymer fibers, two-component thermoplastic polymer fibers, or combinations thereof; The single-component thermoplastic polymer fiber is water-soluble at the repulping temperature; and At least the sheath component of the bicomponent thermoplastic polymer fiber is water-soluble at the repulping temperature.

11. The three-dimensional (3D) molded product of claim 1, wherein the thermoplastic polymer binder comprises a two-component polymer fiber, the two-component polymer fiber comprising: The core component is made of a material whose melting temperature is higher than the temperature at which the air-laid preform (10) is heated during hot pressing; and The sheath component is made of a material with a melting temperature lower than the temperature at which the air-laid blank (10) is heated during hot pressing.

12. The three-dimensional (3D) molded product of claim 1, wherein the thermoplastic polymer binder is a two-component polymer fiber, the two-component polymer fiber comprising: The core component is made of a material whose melting temperature is higher than the temperature at which the air-laid preform (10) is heated during hot pressing; and The sheath component is made of a material with a melting temperature lower than the temperature at which the air-laid blank (10) is heated during hot pressing.

13. The three-dimensional (3D) molded product according to claim 1 or 11, wherein the thermoplastic polymer binder comprises a one-component thermoplastic polymer fiber, said one-component thermoplastic polymer fiber being made of: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

14. The three-dimensional (3D) molded product according to claim 1, wherein the thermoplastic polymer binder is a one-component thermoplastic polymer fiber, said one-component thermoplastic polymer fiber being made of: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

15. The three-dimensional (3D) molded product of claim 1, wherein the thermoplastic polymer binder comprises a two-component thermoplastic polymer fiber, the two-component thermoplastic polymer fiber comprising: The core component is made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof; and ii) optionally one or more additives; and The sheath component is made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

16. The three-dimensional (3D) molded product according to claim 1, wherein the thermoplastic polymer binder is a two-component thermoplastic polymer fiber, the two-component thermoplastic polymer fiber comprising: The core component is made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof; and ii) optionally one or more additives; and The sheath component is made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

17. The three-dimensional (3D) molded product of claim 1, wherein the thermoplastic polymer binder comprises a two-component thermoplastic polymer fiber, the two-component thermoplastic polymer fiber comprising: The core component is made from: i) a material selected from polyethylene, ethylene-acrylic acid copolymer, ethylene-vinyl acetate, polypropylene, polystyrene, polybutylene adipate, polybutylene succinate, polylactic acid, polyethylene terephthalate, polycaprolactone, copolymers thereof, or mixtures thereof; and ii) optionally one or more additives; and The sheath component is made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

18. The three-dimensional (3D) molded product according to claim 1, wherein the thermoplastic polymer binder is a two-component thermoplastic polymer fiber, the two-component thermoplastic polymer fiber comprising: The core component is made from: i) a material selected from polyethylene, ethylene-acrylic acid copolymer, ethylene-vinyl acetate, polypropylene, polystyrene, polybutylene adipate, polybutylene succinate, polylactic acid, polyethylene terephthalate, polycaprolactone, copolymers thereof, or mixtures thereof; and ii) optionally one or more additives; and The sheath component is made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

19. The three-dimensional (3D) molded product according to claim 1 or 2, wherein the thermoplastic polymer binder comprises a thermoplastic polymer powder made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

20. The three-dimensional (3D) molded product according to claim 1 or 2, wherein the thermoplastic polymer binder is a thermoplastic polymer powder made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

21. The three-dimensional (3D) molded product according to claim 1 or 2, wherein the natural fiber is wood fiber.

22. The three-dimensional (3D) shaped product according to claim 21, wherein the natural fiber is cellulose and / or lignocellulose fiber.

23. The three-dimensional (3D) molded product according to claim 21, wherein the natural fiber is cellulose and / or lignocellulose pulp fiber produced by chemical, mechanical and / or chemimechanical pulping of softwood and / or hardwood.

24. The three-dimensional (3D) shaped product according to claim 21, wherein the natural fiber is selected from cellulose and / or lignocellulose pulp fibers in the form of sulfate pulp, sulfite pulp, thermomechanical pulp, high-temperature thermomechanical pulp, mechanical fibers intended for use in medium-density fiberboard, chemi-thermomechanical pulp, high-temperature chemi-thermomechanical pulp, or combinations thereof.

25. The three-dimensional (3D) molded product according to claim 1 or 2, wherein the three-dimensional (3D) molded product (20) has a strength of 15 to 240 kg / m³. 3 The density selected within the specified interval.

26. The three-dimensional (3D) molded product according to claim 25, wherein the three-dimensional (3D) molded product (20) has a strength of 15 to 200 kg / m³. 3 The density selected within the specified interval.

27. The three-dimensional (3D) molded product according to claim 26, wherein the three-dimensional (3D) molded product (20) has a strength of 15 to 150 kg / m³. 3 The density selected within the specified interval.

28. The three-dimensional (3D) molded product according to claim 27, wherein the three-dimensional (3D) molded product (20) has a strength of 15 to 100 kg / m³. 3 The density selected within the specified interval.

29. The three-dimensional (3D) molded product according to claim 1 or 2, wherein the three-dimensional (3D) molded product (20) comprises at least one surface (21, 23), the at least one surface (21, 23) being heat-sealed to inhibit defleasing from the at least one surface (21, 23).

30. The three-dimensional (3D) molded product according to claim 1 or 2, wherein the three-dimensional (3D) molded product (20) comprises at least one surface coated with a surface layer selected from a down-proof layer, a moisture-proof layer, a tactile layer, and a coloring layer.

31. The three-dimensional (3D) molded product according to claim 30, wherein the surface layer comprises at least one substance prepared as a solution, emulsion and / or dispersion, and is applied to at least one surface of the three-dimensional (3D) molded product (20) by spraying it onto at least one surface of the three-dimensional (3D) molded product (20) or the air-laid preform (10).

32. The three-dimensional (3D) molded product according to claim 31, wherein the material is selected from thermoplastic polymers, natural polymers, or mixtures thereof.

33. The three-dimensional (3D) molded product according to claim 32, wherein the substance is selected from starch, agar, guar gum, locust bean gum, and / or microfibrillated or nanofibrillated cellulose or lignocellulose.

34. The three-dimensional (3D) molded product according to claim 30, wherein the surface layer is attached to at least one surface of the three-dimensional (3D) molded product (20) by means of a water-soluble hot melt adhesive and / or by means of a water-soluble adhesive film.

35. An air-laid preform (10) configured for hot pressing into a three-dimensional (3D) formed product (20), the air-laid preform (10) comprising: The concentration is at least 70% natural fiber based on the weight of the air-laid preform (10); and A thermoplastic polymer adhesive selected with a concentration in the range of 2.5% to 30% based on the weight of the air-laid preform (10), wherein The air-laid preform (10) is recyclable in the re-slurrying process; and At least a portion of the thermoplastic polymer adhesive is water-soluble at the re-pulping temperature of the re-pulping process. in The thermoplastic polymer adhesive comprises thermoplastic polymer fibers, which are selected from single-component thermoplastic polymer fibers, two-component thermoplastic polymer fibers, or combinations thereof; The one-component thermoplastic polymer fiber is water-soluble at the repulping temperature, and the one-component thermoplastic polymer fiber has a solubility greater than 0.5 g thermoplastic polymer binder / 100 ml water; and At least the sheath component of the bicomponent thermoplastic polymer fiber is water-soluble at the repulping temperature, and the sheath component of the bicomponent thermoplastic polymer fiber has a solubility greater than 0.5 g thermoplastic polymer binder / 100 ml water. The repulping temperature is in the range of 20°C to 100°C.

36. The air-laid preform of claim 35, wherein at least a portion of the thermoplastic polymer binder is water-soluble at a temperature selected from the range of 20°C to 100°C.

37. The air-laid preform of claim 35, wherein at least a portion of the thermoplastic polymer binder is water-soluble at a temperature selected from the range of 30°C to 90°C.

38. The air-laid preform of claim 35, wherein at least a portion of the thermoplastic polymer binder is water-soluble at a temperature selected from the range of 30°C to 70°C.

39. The air-laid preform according to any one of claims 35 to 38, wherein at least a portion of the thermoplastic polymer binder has a softening point not exceeding the degradation temperature of the natural fiber.

40. The air-laid preform according to any one of claims 35 to 38, wherein the thermoplastic polymer binder has a softening point not exceeding the degradation temperature of the natural fibers.

41. The air-laid web blank according to any one of claims 35 to 38, wherein The thermoplastic polymer adhesive is a thermoplastic polymer fiber, which is selected from single-component thermoplastic polymer fibers, two-component thermoplastic polymer fibers, or combinations thereof; The single-component thermoplastic polymer fiber is water-soluble at the repulping temperature; and At least the sheath component of the bicomponent thermoplastic polymer fiber is water-soluble at the repulping temperature.

42. The air-laid preform of claim 35, wherein the thermoplastic polymer binder comprises bicomponent polymer fibers, the bicomponent polymer fibers comprising: The core component is made of a material whose melting temperature is higher than the temperature at which the air-laid preform (10) is heated during hot pressing; and The sheath component is made of a material with a melting temperature lower than the temperature at which the air-laid blank (10) is heated during hot pressing.

43. The air-laid preform according to claim 35, wherein the thermoplastic polymer binder is a two-component polymer fiber, the two-component polymer fiber comprising: The core component is made of a material whose melting temperature is higher than the temperature at which the air-laid preform (10) is heated during hot pressing; and The sheath component is made of a material with a melting temperature lower than the temperature at which the air-laid blank (10) is heated during hot pressing.

44. The air-laid preform according to claim 35 or 42, wherein the thermoplastic polymer binder comprises a one-component thermoplastic polymer fiber made of: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

45. The air-laid preform according to claim 35, wherein the thermoplastic polymer binder is a one-component thermoplastic polymer fiber, the one-component thermoplastic polymer fiber being made of: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

46. ​​The air-laid preform of claim 35, wherein the thermoplastic polymer binder comprises a two-component thermoplastic polymer fiber, the two-component thermoplastic polymer fiber comprising: The core component is made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof; and ii) optionally one or more additives; and The sheath component is made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

47. The air-laid preform according to claim 35, wherein the thermoplastic polymer binder is a two-component thermoplastic polymer fiber, the two-component thermoplastic polymer fiber comprising: The core component is made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof; and ii) optionally one or more additives; and The sheath component is made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

48. The air-laid preform of claim 35, wherein the thermoplastic polymer binder comprises a two-component thermoplastic polymer fiber, the two-component thermoplastic polymer fiber comprising: The core component is made from: i) a material selected from polyethylene, ethylene-acrylic acid copolymer, ethylene-vinyl acetate, polypropylene, polystyrene, polybutylene adipate, polybutylene succinate, polylactic acid, polyethylene terephthalate, polycaprolactone, copolymers thereof, or mixtures thereof; and ii) optionally one or more additives; and The sheath component is made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

49. The air-laid preform according to claim 35, wherein the thermoplastic polymer binder is a two-component thermoplastic polymer fiber, the two-component thermoplastic polymer fiber comprising: The core component is made from: i) a material selected from polyethylene, ethylene-acrylic acid copolymer, ethylene-vinyl acetate, polypropylene, polystyrene, polybutylene adipate, polybutylene succinate, polylactic acid, polyethylene terephthalate, polycaprolactone, copolymers thereof, or mixtures thereof; and ii) optionally one or more additives; and The sheath component is made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

50. The air-laid preform of claim 35, wherein the thermoplastic polymer binder comprises a thermoplastic polymer powder made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

51. The air-laid preform according to claim 35, wherein the thermoplastic polymer binder is a thermoplastic polymer powder made from: i) a material selected from polyvinyl alcohol, polyethylene glycol, poly(2-ethyl-2-oxazoline), polyvinyl ether, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, copolymers thereof, or mixtures thereof, and ii) optionally one or more additives.

52. The air-laid blank according to any one of claims 35 to 38, wherein the natural fiber is wood fiber.

53. The air-laid web blank according to claim 52, wherein the natural fiber is cellulose and / or lignocellulose fiber.

54. The air-laid web blank according to claim 52, wherein the natural fiber is cellulose and / or lignocellulose pulp fiber produced by chemical, mechanical and / or chemimechanical pulping of softwood and / or hardwood.

55. The air-laid blank according to claim 52, wherein the natural fiber is cellulose and / or lignocellulose pulp fiber selected from the following forms: sulfate pulp, sulfite pulp, thermomechanical pulp, high-temperature thermomechanical pulp, mechanical fibers intended for use in medium-density fiberboard, chemi-thermomechanical pulp, high-temperature chemi-thermomechanical pulp, or combinations thereof.

56. A method for manufacturing a three-dimensional (3D) shaped product (20), the method comprising hot pressing (S1) a male mold tool (30) into an air-laid blank (10) according to any one of claims 35 to 55.

57. A method for manufacturing a three-dimensional (3D) shaped product (20), the method comprising hot pressing (S1) an air-laid blank (10) between a male mold tool (30) and a female mold tool (50) according to any one of claims 35 to 55.

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