Method for manufacturing an absorbent web-based product, absorbent web-based product and apparatus for manufacturing an absorbent web-based product

Abstract

The present disclosure relates to a method of manufacturing an absorbent web-based product, comprising the steps of: preparing a fibrous foam, wherein the preparing comprises dispersing fibers and one or more surfactants in a liquid, having a fiber content of 5% to 60% by weight, a surfactant content of 0.02% to 1.20% by weight, and a liquid content of 40% to 95% by weight, and supplying and dispersing a gas in the liquid until a gas content of 64% or more by volume is reached, forming the fibrous foam into a foam layer, draining the fibrous foam in the foam layer to form a fibrous web, wherein the fibrous web has a liquid content of 20% to 85% by weight, and drying the fibrous web to obtain an absorbent web-based product.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing absorbent web-based products, particularly by preparing and forming fibrous foam into a foam layer, absorbent web-based products, and apparatus for manufacturing absorbent web-based products. Background Technology

[0002] Absorbency-based products are widely used in modern society. Toilet paper, tissues such as hand towels and household (kitchen) towels, wipes, facial tissues, napkins, and tissue hand towels are basic commodities.

[0003] These products are typically manufactured using a wet web forming process, which consists of: preparing an aqueous pulp (paper pulp) for the fibers; feeding the pulp into a headbox that spreads the pulp onto the wire, allowing liquid to drain while maintaining most of the fibers in a continuous web form; pressing; drying; and optionally winding and confectioning to produce the finished product.

[0004] WO 2016 / 173641 describes a wet web forming process for manufacturing cotton paper webs, comprising the following steps: providing pulp fibers, forming an aqueous suspension of the fibers, feeding the suspension into a cotton paper making headbox, depositing the suspension onto wire to form a wet web, dewatering the wet web, and drying and wrinkling the web.

[0005] The main physical properties of wet-laid web products include, for example, basis weight, strength, softness, absorbency (especially for water-based systems), and resistance to lint and dust.

[0006] While wet web forming can produce products with unique properties, it struggles to achieve lightweight, low-density absorbent products. However, this manufacturing process still requires significant amounts of water and energy, making the search for more sustainable / environmentally friendly production methods desirable. Alternative production methods may rely on foam formation. However, foam formation processes can be slower than wet web forming, limiting production efficiency and capacity. Furthermore, it has been demonstrated that achieving high-quality products with high viscosity is difficult when relying on foam formation technologies.

[0007] This disclosure aims to address one or more of the aforementioned disadvantages. In one aspect, the object of this disclosure is to provide raw materials and / or energy-saving processes for manufacturing absorbent web-based products.

[0008] A further objective is to provide an apparatus for manufacturing absorbent web-based products.

[0009] The further objectives will become apparent from the following detailed description. Summary of the Invention

[0010] This disclosure provides raw materials and / or energy-saving processes for manufacturing absorbent web-based products. In particular, this disclosure relates to a method for manufacturing absorbent web-based products, comprising the following steps: - Preparing fibrous foam, wherein the preparation comprises dispersing fibers, one or more surfactants in a liquid and / or foam, wherein the fiber content is 5% to 60% by weight, the surfactant content is 0.02% to 1.20% by weight, and the liquid content is 40% to 95% by weight, and supplying and dispersing gas in the liquid and / or foam until a gas content of 64% or more by volume is achieved; - Forming fibrous foam into a foam layer; - Discharge fibrous foam from the foam layer to form a fibrous web, wherein the fibrous web has a liquid content of 20% to 85% by weight; and - Dry fibrous webs to obtain absorbent web-based products.

[0011] More generally, foam can be prepared first, and then solids and gases can be dispersed in the foam. Alternatively, foam can be prepared, and solids can be dispersed in both the liquid and the foam. Alternatively, solids can be dispersed in the liquid. In each of these scenarios, the solid may include or be composed of fibers.

[0012] Regarding the preparation, the fiber content may be 5% to 60% or 8% to 45% by weight, or 9% to 40% by weight, or 9.5% to 35% by weight, or 10% to 30% by weight, or 10% to 25% by weight, or 10% to 20% by weight; the gas content may be 70% or more by volume, or 75% or more by volume, or 80% or more by volume, or 85% or more by volume, or 90% or more by volume; the surfactant content may be 0.02% to 1.1% by weight, or 0.02% to 1.0% by weight, or 0.05% to 0.8% by weight; and the liquid content may be 40% to 95% by weight, or 55% to 92% by weight, or 53.9% to 91.8% by weight, or 65% to 85% by weight, or 78.9% to 89.95% by weight. More generally, the liquid content can be 100% minus the sum of the surfactant content and the fiber content. Alternatively, the liquid content can be slightly lower, and the further content of the gas-dispersed liquid can be referred to as the remainder.

[0013] The present invention also relates to a method for manufacturing an absorbent web-based product, comprising the following steps: - Fibrous foam is prepared by supplying fibers and one or more surfactants to a liquid and / or foam and dispersing gas in the liquid and / or foam, achieving a fiber volume fraction of 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less; - Forming fibrous foam into a foam layer; - Discharge fibrous foam from the foam layer to form a fibrous web, wherein the fibrous web has a liquid content of 20% to 85% by weight; and - Dry fibrous webs to obtain absorbent web-based products.

[0014] More generally, the foam can be prepared first, and then the dispersion of the solid and gas within the foam can be performed. Alternatively, the foam can be prepared, and the solid dispersion can be dispersed in both the liquid and the foam. Alternatively, the solid can be dispersed in the liquid. In each of these cases, the solid may comprise or be composed of fibers.

[0015] In one aspect, this disclosure provides an absorbent web-based product having excellent properties, particularly one or more of excellent basis weight, softness, strength, and absorbency. In particular, this disclosure relates to absorbent web-based products that can be manufactured by the methods described above.

[0016] This disclosure also relates to an absorbent web-based product comprising at least 70% by weight of fiber material based on the total weight of the absorbent web-based product, wherein the absorbent web-based product has a density of 5 g / m². 2 or more, or 8g / m 2 or more, or 10g / m 2 or more and 500g / m 2 Or smaller, or 300g / m 2 Or smaller, or 200g / m 2 Or smaller, or 150g / m 2 Or smaller, or 10 to 120 g / m 2 The base weight and 5 to 200 kg / m 3 or 8 to 150 kg / m 3 or 10 to 100 kg / m 3 or 10 to 70 kg / m 3 The density.

[0017] In one aspect, this disclosure provides an apparatus for manufacturing absorbent web-based products. In particular, this disclosure relates to an apparatus for manufacturing absorbent web-based products, comprising: - A fibrous foam preparation apparatus for preparing fibrous foam. - A foam layer forming apparatus for forming fibrous foam into a foam layer; - A discharge device that discharges fibrous foam from a foam layer to form a fibrous web having a liquid content of 20% to 85% by weight; and - A drying device that dries fibrous webs to obtain absorbent web-based products. The fibrous foam preparation apparatus includes a supply device for supplying fibers, one or more surfactants, liquids, and gases, wherein the fiber content is 5% to 60% by weight, the surfactant content is 0.02% to 1.20% by weight, the liquid content is 40% to 95% by weight, and the gas content is 64% or more by volume.

[0018] This disclosure also relates to an apparatus for manufacturing absorbent web-based products, comprising: - A fibrous foam preparation apparatus for preparing fibrous foam. - A foam layer forming apparatus for forming fibrous foam into a foam layer; - A discharge device that discharges fibrous foam from a foam layer to form a fibrous web having a liquid content of 20% to 85% by weight; and - A drying device that dries fibrous webs to obtain absorbent web-based products. The fibrous foam preparation apparatus uses fibers, liquids, and gases to prepare fibrous foam, and the fiber volume fraction is 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less.

[0019] In particular, this disclosure relates to the following embodiments (items): 1. A method for manufacturing an absorbent web-based product, comprising the following steps: - Preparing fibrous foam, wherein the preparation comprises dispersing fibers and one or more surfactants in a liquid and / or foam, wherein the fiber content is 5% to 60% by weight, the surfactant content is 0.02% to 1.20% by weight, and the liquid content is 40% to 95% by weight, and supplying and dispersing gas in the liquid and / or foam until a gas content of 64% or more by volume is achieved; - The fibrous foam is formed into a foam layer; - Discharging the fibrous foam from the foam layer to form a fibrous web, wherein the fibrous web has a liquid content of 20% to 85% by weight; and - Dry the fibrous web to obtain an absorbent web-based product.

[0020] 2. The method according to Project 1, wherein feedback loop control is used to perform the dispersion of the gas in the liquid and / or foam, optionally including measuring at least one of the gas content, the density of the gas-liquid dispersion, and the electrical conductivity of the gas-liquid dispersion, and adding and dispersing the gas until at least one of the gas content, the density, and the electrical conductivity reaches a target value.

[0021] 3. The method according to item 1 or 2, wherein the preparation comprises supplying the gas and the liquid into a container such that the ratio between the amount of liquid supplied and the amount of gas supplied is within a predetermined range or reaches a predetermined value, and mechanically mixing in the container for at least a predetermined time or until foam parameters, such as foam height and / or gas content, reach a predetermined minimum threshold.

[0022] 4. The method according to any one of the preceding items, wherein the preparation comprises supplying a solid with a solid content of 5% to 60% by weight, and wherein at least 80% by weight of the solid is fiber.

[0023] 5. The method according to any one of the preceding items, wherein the liquid comprises at least 80% water by weight, and / or the gas used to prepare the fibrous foam comprises at least 95% air by volume.

[0024] 6. The method according to any one of the preceding items, wherein the fibrous foam comprises a liquid having at least 80% water by weight and / or a gas having at least 95% air by volume.

[0025] 7. A method for manufacturing an absorbent web-based product, comprising the following steps: - A fibrous foam is prepared by supplying fibers and one or more surfactants to a liquid and / or foam and dispersing gas in the liquid and / or foam, thereby achieving a fiber volume fraction of 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less; - The fibrous foam is formed into a foam layer; - Discharging the fibrous foam from the foam layer to form a fibrous web, wherein the fibrous web has a liquid content of 20% to 85% by weight; and - Dry the fibrous web to obtain an absorbent web-based product.

[0026] 8. The method according to Project 7, wherein the prepared fibrous foam comprises solids, and the solids volume fraction is 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less. Furthermore, at least 80% of the solid is fiber by weight.

[0027] 9. The method according to item 7 or 8, wherein the fiber content is 5% to 60% by weight, and / or the liquid content is 40% to 95% by weight, and the gas content is 64% or more by volume, optionally at least 70%, at least 75%, at least 80%, at least 85% or at least 90% by volume.

[0028] 10. The method according to any one of the preceding items, wherein the preparation comprises processing dried fibers or solids, moisturizing fibers or solids, liquid slurries or foams, and fibers into the fibrous foam.

[0029] 11. The method according to item 10, wherein the processing is performed prior to the transport, or The processing is performed at least in part by a transport device that carries the fibrous foam to a forming device that forms the fibrous foam into the foam layer. Optionally, the processing is performed by the transport device.

[0030] 12. The method according to item 10 or 11, wherein the processing is performed by a processing device and the discharge of the fibrous foam is performed by a discharge device. Optionally, one or more of the following components are part of an integral structural unit: the processing device, the transport device, the forming device, and the discharging device, wherein, optionally, the processing device includes the transport device.

[0031] 13. The method according to item 12, wherein the processing includes increasing the pressure applied to the liquid slurry or the fibrous foam during transport in the downstream direction by the transport device, wherein the increase in pressure is optionally at least 0.1 bar and optionally an increase of 10 bar or less.

[0032] 14. The method according to item 12 or 13, wherein the processing includes successively applying multiple different pressure levels in the downstream direction, wherein the pressure levels are optionally reduced two or more times and / or the pressure levels are optionally increased two or more times.

[0033] 15. The method according to any one of items 10 to 14, wherein the processing includes at least one of: shearing, elongation and / or distribution mixing, defiberization, anti-flocculation, refining, dispersion, disintegration, alteration of fiber shape, heating, and addition of chemical additives.

[0034] 16. The method according to any one of the preceding items, wherein the preparation includes supplying a rheology modifier.

[0035] 17. The method according to any one of the preceding items, wherein the discharge of the fibrous foam comprises mechanical discharge, optionally consisting of mechanical discharge.

[0036] 18. The method according to any one of the foregoing items, wherein the absorbency-based product has a liquid content of 0.5% to 15% by weight, optionally 1% to 15% by weight, or 1% to 10% by weight, or 1.5% to 8% by weight, or 1.8% to 6.5% by weight, or 2% to 5% by weight. Optionally, the absorbency-based product has a water content of 0.5% to 10% by weight, optionally 1% to 10% by weight, or 1.5% to 8% by weight, or 1.8% to 6.5% by weight, or 2% to 5% by weight.

[0037] 19. The method according to any one of the preceding items, wherein the prepared fibrous foam has a solid content of more than 10% by weight, and optionally a fiber content of more than 10% by weight.

[0038] 20. The method according to any one of the preceding items, wherein forming the fibrous foam into a foam layer includes making the fibrous foam planar.

[0039] 21. The method according to any one of the preceding items, comprising contacting the fibrous foam with at least one rotatable device and rotating the at least one rotatable device to transport the fibrous foam, optionally rotating the at least one rotatable device at 100 to 5000 revolutions per minute.

[0040] 22. The method according to item 21, wherein rotation of the at least one rotatable device promotes at least a portion, or optionally all, of the fiber to be defibrinated.

[0041] 23. The method according to item 21 or 22, wherein the fibrous foam is transported through at least one processing device selected from the following list: industrial mixer, screw kneader, industrial kneading machine, extruder, single-screw or twin-screw machine, single-screw or twin-screw continuous kneader, twin-screw or multi-screw machine, conical screw mixer, wherein the at least one processing device includes the at least one rotatable device.

[0042] 24. The method according to any one of items 21 to 23, wherein the rotatable device is housed in a housing, and the minimum distance between the rotatable device and the housing during rotation is in the range of 0.2% to 20% of the diameter of the at least one rotatable device, and optionally in the range of 0.3 mm to 20 mm.

[0043] 25. The method of claim 23, comprising supplying at least one component selected from the following list to the fibrous foam during transport of the fibrous foam through the processing device: - A liquid, such as water, which may optionally contain one or more additives; - Gases, such as air; - Foam and / or liquid slurries; and - Solids, such as fibers, powders and / or granules.

[0044] 26. The method according to any one of items 21 to 25, wherein the rotation of said at least one rotatable device comprises rotating a twin-screw, a single-screw, or a multi-screw, and Transporting the fibrous foam by rotating the at least one rotatable device includes one or more of the following: accelerating the fibrous foam; decelerating the fibrous foam; applying a shear force to the fibrous foam.

[0045] 27. The method according to any one of items 21 to 26, wherein the rotation of the at least one screw is performed in a screw assembly such as an extruder or a screw mixer, the screw assembly comprising a housing and the at least one screw, wherein in a cross section of the at least one screw perpendicular to the axis of rotation, the minimum distance between the at least one screw and the opposing inner surfaces of the housing is in the range of 1% to 20% of the outer diameter of the screw, optionally in the range of 0.3 mm to 20 mm.

[0046] 28. The method according to any one of items 21 to 27, wherein the at least one rotatable device comprises at least a first screw and a second screw, and the closest approach distance between the first screw and the second screw during rotation is in the range of 0.3 mm to 20 mm.

[0047] 29. The method according to any one of items 21 to 28, wherein the at least one rotatable device comprises a plurality of screws and at least one housing housing the plurality of screws, and the nearest approach distance between any of the plurality of screws and the relative inner surfaces of the at least one housing housing housing the at least one screw is in the range of 0.3 mm to 20 mm.

[0048] 30. The method according to any one of the preceding items, wherein the fibrous foam is displaced by a displacement pump prior to its formation, the displacement pump being optionally a rotary cam pump, a progressive chamber pump, a rotary gear pump, a piston pump, a diaphragm pump, a screw pump, a gear pump, a hydraulic pump, a rotary vane pump, a peristaltic pump, a rope pump, or a flexible impeller pump.

[0049] 31. The method according to any one of the preceding items, wherein the discharge comprises applying a vacuum to the foam layer at a constant pressure or a varying pressure, wherein the varying pressure is optionally a pressure that decreases at least once in the downstream direction of transport.

[0050] 32. The method according to any one of the foregoing items, wherein the discharge is performed by applying a vacuum to the foam layer in at least two consecutive stages, optionally to reduce the pressure.

[0051] 33. The method according to any one of the foregoing items, wherein forming the fibrous foam into the foam layer is performed at least partially in a compression mold and / or a headbox and / or a cylindrical die forming device and / or a chest-sucking roller forming device, and / or The processing and / or formation of the foam layer is performed in a controlled pressure chamber. Optionally, the molding die is a slit molding die with an adjustable molding die gap, wherein the fibrous foam is processed into continuous fibrous webs or sheets on a moving continuous dewatering / conveyor unit.

[0052] 34. The method according to any one of the preceding items, comprising a step of preparing a slurry prior to the step of preparing the fibrous foam, the slurry comprising at least one component selected from the group consisting of: water, fiber, surfactant, binder and slip agent; wherein the preparation of the slurry is optionally performed at least in part in a high-consistency mixing apparatus.

[0053] 35. The method according to any one of the preceding items, wherein the drying is heat drying, freeze drying, infrared drying, contact drying, impact drying, microwave drying, or air drying.

[0054] 36. The method according to any one of the preceding items, wherein the preparation of the fibrous foam comprises supplying at least one surfactant or a mixture of surfactants, said surfactant optionally selected from anionic surfactants, cationic surfactants, amphoteric surfactants, amphoteric surfactants, and nonionic surfactants.

[0055] 37. The method according to any one of the preceding items, wherein the preparation of the fibrous foam comprises supplying at least one nonionic surfactant or a mixture of surfactants containing at least one nonionic surfactant, said nonionic surfactant optionally being selected from the group consisting of: amine oxides, alkyl glucosides, alkyl polyglucosides, polyhydroxy fatty acid amides, alkoxylated mono- and di-fatty acid esters, alkoxylated fatty alcohols, alkoxylated alkylphenols, fatty acid monoglycerides, polyoxyethylene sorbitol, and sucrose esters.

[0056] 38. The method according to item 37, wherein the at least one nonionic surfactant is selected from the group consisting of alkyl glucosides, alkyl polyglucosides and alkoxylated fatty alcohols, and the at least one nonionic surfactant is optionally an alkyl polyglucoside of general formula (1): R 1 -O-(R 2 ) n -H (1) in, R 1 It is a straight-chain or branched hydrocarbon group with 4 to 20 carbon atoms. R 2 It consists of hexose or pentose units. n is between 1 and 5.

[0057] 39. The method according to any one of the preceding items, wherein the preparation of the fibrous foam and the transport of the fibrous foam to the foam layer forming apparatus are facilitated by the same mechanical motion.

[0058] 40. A method of manufacturing a final product, including the method according to any one of the preceding items, and including at least one of the following steps after drying: web treatment, winding, refining, and conversion into a packaged or unpackaged final product.

[0059] 41. An absorbent web-based product that can be manufactured by the method according to any one of the preceding items.

[0060] 42. The absorbency-based web product according to item 41 has 5 g / m 2 Up to 500 g / m 2 The base weight and 5 kg / m 3Up to 200 kg / m 3 The density, and / or the variation σ of the basis weight as measured according to SCAN-P 92:09 is less than 20%, less than 15%, less than 10%, less than 5%, less than 3%, or less than 2% of the average basis weight of the absorbency based on the web of the product.

[0061] 43. An absorbent web-based product comprising at least 70% by weight of fiber material based on the total weight of the absorbent web-based product. The absorbency of the web-based product is 5 g / m 2 Up to 500g / m 2 The base weight and 5 kg / m 3 Up to 200kg / m 3 The density.

[0062] 44. The absorbent web-based product according to item 43, wherein the variation in basis weight σ measured according to SCAN-P 92:09 is less than 20%, less than 15%, less than 10%, less than 5%, less than 3%, or less than 2% of the average basis weight of the absorbent web-based product.

[0063] 45. An absorbent web-based product according to item 43 or 44, wherein the absorbent web-based product has an upper side and a lower side, and the density of the absorbent web-based product in the central region located in the thickness direction between the upper side and the lower side is lower than the density of the absorbent web-based product in the region located on the lower side and / or the upper side.

[0064] 46. ​​Absorbent web-based products according to items 43 to 45, which contain surfactants.

[0065] 47. An absorbent web-based product according to any one of items 43 to 46, comprising one or more of the following (a) to (d): (a) at least 0.2% by weight of one or more binders, (b) at least 0.05% by weight of one or more rheology modifiers, (c) at least 0.01% by weight of one or more surfactants, and (d) At least 0.2% by weight of one or more slip agents, The total weight of each product based on the absorbency of the web material.

[0066] 48. A multi-layered product comprising at least one layer made of an absorbent web-based product as described in any one of items 43 to 47, optionally further comprising at least one nonwoven layer and / or at least one cotton paper layer, optionally conventional wet-pressed paper layer and / or structured layer and / or textured layer.

[0067] 49. Equipment for manufacturing absorbent web-based products, comprising: - A fibrous foam preparation apparatus for preparing fibrous foam. - A foam layer forming apparatus for forming the fibrous foam into a foam layer; - A discharge device that discharges fibrous foam from the foam layer to form a fibrous web having a liquid content of 20% to 85% by weight; and - A drying apparatus that dries the fibrous web to obtain an absorbent web-based product. The fibrous foam preparation apparatus includes a supply device for supplying fibers, one or more surfactants, liquids, and gases, wherein the fiber content is 5% to 60% by weight, the surfactant content is 0.02% to 1.20% by weight, the liquid content is 40% to 95% by weight, and the gas content is 64% or more by volume.

[0068] 50. The apparatus according to item 49, wherein the fibrous foam preparation apparatus includes a solid supply device for supplying solids, wherein the solid content is 5% to 60% by weight, and wherein at least 80% by weight of the solids are fibers.

[0069] 51. The apparatus according to item 49 or 50, wherein the supply device supplies a liquid and / or foam, the surfactant, the fiber and the gas dispersed in the liquid and / or foam, the liquid and / or foam comprising at least 80% water by weight, and / or the gas dispersed in the liquid and / or foam, the gas comprising at least 95% air by volume.

[0070] 52. The apparatus according to any one of items 49 to 51, wherein the fibrous foam preparation apparatus prepares a gas-liquid dispersion comprising a liquid content of at least 80% by weight of water and / or a gas content of at least 95% by volume of air.

[0071] 53. Equipment for manufacturing absorbent web-based products, comprising: - A fibrous foam preparation apparatus for preparing fibrous foam. - A foam layer forming apparatus for forming the fibrous foam into a foam layer; - A discharge device that discharges fibrous foam from the foam layer to form a fibrous web having a liquid content of 20% to 85% by weight; and - A drying apparatus that dries the fibrous web to obtain an absorbent web-based product. The fibrous foam preparation apparatus thereof prepares fibrous foam having fibers, liquid and gas, and wherein the fiber volume fraction is 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less.

[0072] 54. The apparatus according to item 53, wherein the fibrous foam preparation device prepares fibrous foam having a solid content, wherein the solid volume fraction is 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less. Furthermore, at least 80% of its solid content is fiber content.

[0073] 55. The device according to item 53 or 54, wherein the fiber content is 5% to 60% by weight, and / or the liquid content is 40% to 95% by weight, and the gas content is 64% or more by volume, optionally at least 70%, at least 75%, or at least 80%, or at least 85%, or at least 90% by volume.

[0074] 56. The apparatus according to any one of items 49 to 55, wherein the fibrous foam preparation apparatus comprises a processing device for processing liquid slurry or foam and fibers into said fibrous foam.

[0075] 57. The apparatus according to item 56, comprising a transport device for transporting the liquid slurry and / or the foam and / or the fibrous foam to the foam layer forming apparatus, wherein, optionally, the transport device performs at least a portion of the processing or performs the processing itself. Optionally, the transport device performs the processing.

[0076] 58. The equipment according to item 56 or 57, wherein one or more of the following components are part of an integral structural unit: the processing device, the fibrous foam preparation device, the transport device, the forming device, and the discharging device.

[0077] 59. The device according to item 57 or item 58, such as that belonging to item 57, wherein the transport device includes a pressurization section that increases the pressure applied to the liquid slurry or the fibrous foam during transport by the transport device in a downstream transport direction, wherein the pressure increase is optionally at least 0.1 bar and optionally an increase of 10 bar or less.

[0078] 60. The device according to item 59, wherein the pressurization section successively applies multiple different pressure levels in the downstream direction, the pressure levels decreasing at least twice and / or increasing at least twice.

[0079] 61. The apparatus according to any one of items 56 to 60, wherein the processing apparatus performs at least one of the following: shearing, elongation and / or distribution mixing, defiberization, anti-flocculation, refining, dispersion, disintegration, fiber shape alteration, heating, and addition of chemical additives.

[0080] 62. The apparatus according to any one of items 49 to 61, wherein the fibrous foam preparation apparatus facilitates the preparation of the fibrous foam and the transport of the fibrous foam to the foam layer forming apparatus by the same mechanical motion, and / or wherein the fibrous foam preparation apparatus transports the fibrous foam to the forming apparatus.

[0081] 63. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 62, further comprising one or more solid supply devices for supplying solids to the fibrous foam preparation apparatus, and one or more liquid supply devices for supplying liquids to the fibrous foam preparation apparatus to form the fibrous foam having a solid content of 5% to 60% by weight of the fibrous foam, optionally more than 10% by weight of the fibrous foam, and a liquid content of 40% to 95% by weight of the fibrous foam.

[0082] 64. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 63, wherein the fibrous foam preparation apparatus includes a rheology modifier supply device for supplying a rheology modifier.

[0083] 65. The apparatus for manufacturing absorbent web-based products according to any one of items 49 to 64, wherein the discharge device is a mechanical discharge device.

[0084] 66. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 65, wherein the fibrous foam preparation apparatus prepares the fibrous foam to have a solid content of more than 10% by weight and optionally a fiber content of more than 10% by weight.

[0085] 67. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 66, wherein the fibrous foam forming apparatus causes the fibrous foam to be in a planar form.

[0086] 68. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 67, comprising at least one rotatable device, the apparatus contacting the fibrous foam with the at least one rotatable device and rotating the at least one rotatable device to transport the fibrous foam, optionally rotating the at least one rotatable device at 100 to 5000 revolutions per minute.

[0087] 69. The apparatus for manufacturing absorbent web-based products according to item 68, wherein rotation of the at least one rotatable device facilitates at least one of the following: transport, mixing, defibrilation, applying pressure to the fibrous foam, and establishing pressure on the fibrous foam.

[0088] 70. The apparatus for manufacturing absorbent web-based products according to item 68 or 69, comprising at least one processing device selected from the following list: industrial mixer, screw kneader, industrial kneading machine, extruder, single-screw or twin-screw machine, single-screw or twin-screw continuous kneader, twin-screw or multi-screw machine, conical screw mixer, wherein the at least one processing device includes the at least one rotatable device.

[0089] 71. An apparatus for manufacturing an absorbent web-based product according to any one of items 68 to 70, comprising a housing housing the rotatable device, wherein the minimum distance between the rotatable device and the opposing inner surfaces of the housing is in the range of 0.2% to 20% of the diameter of the at least one rotatable device, and optionally in the range of 0.3 mm to 20 mm.

[0090] 72. An apparatus for manufacturing an absorbent web-based product according to item 69 or 71, comprising a supply device that supplies at least one component selected from the following list while the fibrous foam is being transported through the processing device: - A liquid, such as water, which may optionally contain one or more additives; - Gases, such as air; - Foam and / or liquid slurries; and - Solids, such as fibers, powders and / or granules.

[0091] 73. The apparatus for manufacturing absorbent web-based products according to any one of items 69 to 72, wherein the at least one rotatable device is a twin-screw, single-screw, or multi-screw assembly, and The at least one rotatable device may optionally include one or more of the following sections: an acceleration section that accelerates the fibrous foam being transported through the processing device; a deceleration section that decelerates the fibrous foam being transported through the processing device; and a shearing and / or elongation application section that applies shearing and / or elongation forces to the fibrous foam.

[0092] 74. An apparatus for manufacturing an absorbent web-based product according to any one of items 69 to 73, comprising a screw assembly including a housing and the at least one screw, wherein in a cross section of the at least one screw perpendicular to the axis of rotation, the minimum distance between the at least one screw and the opposing inner surface of the housing is in the range of 1% to 20% of the outer diameter of the screw, optionally in the range of 0.3 mm to 20 mm.

[0093] 75. An apparatus for manufacturing an absorbent web-based product according to any one of items 67 to 74, wherein the at least one rotatable device comprises at least a first screw and a second screw, and the closest approach distance between the first screw and the second screw during rotation is in the range of 0.3 mm to 20 mm.

[0094] 76. An apparatus for manufacturing an absorbent web-based product according to any one of items 69 to 75, wherein the at least one rotatable device comprises a plurality of screws and at least one housing housing the plurality of screws, and the nearest approach distance between any of the plurality of screws and the relative inner surfaces of the at least one housing housing housing the at least one screw is in the range of 0.3 mm to 20 mm.

[0095] 77. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 76, comprising a displacement pump, optionally a rotary cam pump, a progressive chamber pump, a rotary gear pump, a piston pump, a diaphragm pump, a screw pump, a gear pump, a hydraulic pump, a rotary vane pump, a peristaltic pump, a rope pump, or a flexible impeller pump, said displacement pump displacing the fibrous foam prior to the formation.

[0096] 78. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 77, wherein the discharge device applies a vacuum to the foam layer at a constant pressure or at a varying pressure, wherein the varying pressure is optionally a pressure that decreases at least once in the downstream direction of transport.

[0097] 79. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 78, wherein the discharging device applies a vacuum to the foam layer in at least two consecutive stages, optionally at reduced pressure.

[0098] 80. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 79, wherein the foam layer forming apparatus comprises a compression mold and / or a headbox and / or a cylindrical die former and / or a chest-absorbing roller former.

[0099] 81. An apparatus for manufacturing an absorbent web-based product according to any one of items 80 or 56 to 79, such as that belonging to item 80, wherein the processing apparatus and / or the foam layer forming apparatus are disposed in a controlled pressure chamber.

[0100] 82. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 81, comprising a liquid slurry preparation device for preparing an intermediate mixture / slurry foam / slurry solution, the intermediate mixture / slurry foam / slurry solution comprising at least one component selected from the group consisting of: water, fiber, one or more surfactants, one or more binders, and one or more slip agents; The liquid slurry preparation apparatus may optionally include a high-consistency mixing device.

[0101] 83. The apparatus for manufacturing absorbent web-based products according to any one of items 49 to 82, wherein the drying apparatus is a thermal drying apparatus, a freeze drying apparatus, an infrared drying apparatus, a contact drying apparatus, an impact drying apparatus, a microwave drying apparatus, or a ventilated drying apparatus.

[0102] 84. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 83, comprising a surfactant supply device that supplies at least one surfactant or a mixture of surfactants, the surfactant optionally selected from anionic surfactants, cationic surfactants, amphoteric surfactants, zwitterionic surfactants and nonionic surfactants.

[0103] 85. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 84, comprising a temperature control device that controls the temperature inside at least one section of the apparatus.

[0104] 86. An apparatus for manufacturing an absorbent web-based product according to any one of items 49 to 85, comprising a controller for controlling the apparatus to perform the method according to any one of items 1 to 39.

[0105] 87. An apparatus for manufacturing a final product, the apparatus comprising the apparatus according to any one of items 49 to 86, and at least one of the following components: a web processing device, a winding device, a refining device, and a conversion device for converting the final product into a packaged or unpackaged product.

[0106] 88. Use of the equipment according to any one of items 49 to 87 for manufacturing absorbent web-based products.

[0107] Detailed description of this disclosure 1. definition As used herein, the term "absorbent web-based product" refers to a product having a web-like structure comprising fibers and optional other additives and capable of absorbing liquids, moisture, or other substances. In this context, the term "web" (or "web-like structure") refers to a structure such as a fabric, sheet, or material in which individual fibers are placed. In one aspect, the term "absorbent product" characterizes a product having, for example, a water absorption capacity of 4 g / g or more, or 5 g / g or more, or 6 g / g or more, or 10 g / g or more, or 15 g / g or more, or 20 g / g or more as measured according to ISO 12625-8:2010. Furthermore, the water absorption time, as measured according to ISO 12625-8:2010, can be from 1 s to 25 s.

[0108] In this disclosure, "absorbent web-based product" generally refers to a product having at least one sheet, wherein the basis weight of each sheet may be 5 g / m². 2 or more, or 8g / m 2 or more, or 10g / m 2 or more and 500g / m 2 or smaller, 300g / m 2 or smaller, 200g / m 2 Or smaller, or 150g / m 2 Or smaller, or 120g / m 2 Or even smaller. In particular, the basis weight (gram weight) of (monolayer) absorbency based on the web can range from 5 to 500 g / m². 2Or 10 to 120 g / m 2 Furthermore, the absorbency of (monolayer) absorbent products based on web density can range from 5 to 200 kg / m³. 3 or 1 to 100 kg / m 3 Or 8 to 150 kg / m 3 or 10 to 70 kg / m 3 Absorbency-based web products can be single-layer or multi-layer products, which can be customized according to the end-user's needs through further transformation steps. Optionally, absorbency-based web products are single-layer products.

[0109] The term “nonwoven” is very common in the art and, for the purposes of this disclosure, may be further defined in the manner described in ISO 9092:2011.

[0110] As used herein, the term "cotton paper" refers to a base paper produced by a cotton paper machine and containing natural fibers. The term "cotton paper sheet" refers to a sheet of cotton paper obtained from a cotton paper machine. Cotton paper sheets are prepared by a method comprising the following steps: forming an aqueous suspension of pulp fibers, depositing the aqueous suspension onto a filament to form a wet web, and dehydrating, drying, and creping the web.

[0111] As used herein, the term "sheet" refers to, for example, one sheet or one of several sheets in a web-based product that is ultimately absorbent after drying or conversion.

[0112] In one respect, each individual sheet of an absorbent web-based product may consist of a fibrous web comprising one or more layers, such as one, two, three, or four layers. As a “layer,” we understand a web to have a defined stratum of fibers. One or more layers can be formed by depositing one or more foam or feed streams onto a wire having a pressurized single- or multi-layer headbox to form a “multilayer” fibrous web.

[0113] This disclosure covers a multi-layer product comprising at least one layer made of an absorbent web-based product having any one or more of the described characteristics. The multi-layer product may include two or more layers made of an absorbent web-based product. The multi-layer product may include one or more layers of other types (which may be identical or different from each other). For example, the multi-layer product may include one or more tissue paper layers. Each tissue paper layer may be a conventional wet paper layer, such as a structured layer, such as a TAD layer, an ATMOS layer, a crepe tissue paper layer, etc., or a textured layer.

[0114] As used herein, the term "fibrous foam" refers to foam containing fibers. In this context, the term "foam" describes the porous structure of air bubbles separated by a soft solid membrane or liquid medium. The properties of fibrous foam depend in particular on the air content and fiber consistency in the foaming slurry (which in turn determines the fiber volume fraction of the foam), the type of fibers used, and the size and size distribution of the bubbles.

[0115] The rheological properties of the fibrous foam sample were measured using a stress-controlled TAInstruments DHR-2 rheometer equipped with a blade geometry in a cup. The blades were made of stainless steel and featured a commercially available 4-blade blade geometry with a diameter of 15 mm. The cup was 3D printed using stereolithography and had a diameter of 30 mm. The outer wall of the cup had a vertical profile to eliminate wall slippage during rheological measurements. The cup was placed in a temperature-controlled Peltier jacket, which maintained the sample temperature at 25°C throughout all rheological measurements. The fibrous foam sample was loaded into the cup with the aid of a syringe, the tip of which was cut to ensure the entire cup was filled with fibrous foam and that there were no air pockets within the sample. The air content of the fibrous foam sample was determined by weighing it before inserting the foam-filled cup into the rheometer. Subsequently, the blade geometry was lowered into the sample such that the blades were vertically positioned in the center of the cup (16 mm from the bottom of the cup and the top surface of the foam sample).

[0116] For example, three types of rheological measurements can be performed on fibrous foam samples: 1) Amplitude scan measurements from 0.01% to 100% of strain amplitude at a constant angular frequency of 10 rad / s; 2) Frequency sweep measurements from 0.4 rad / s to 100 rad / s with a strain amplitude of 0.03%; and 3) Shear rate scan measurement first measures the shear rate from 0.1 s⁻¹ to 100 s⁻¹ (“upper curve”), and then measures the shear rate from 100 s⁻¹ to 0.01 s⁻¹ (“lower curve”).

[0117] As used herein, the term "surfactant" (or "surfactant") refers to any agent that effectively reduces the surface tension of a liquid (e.g., water) by selective adsorption onto an interface, even at low concentrations. Surfactants can be pure compounds or mixtures of different compounds. Examples of surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, zwitterionic surfactants, and combinations thereof.

[0118] The term "fiber volume fraction" refers to the ratio (V0) between the volume of fibers and the volume of liquid, gas, and solid in a fibrous foam. 纤维 / (V) 液体 +V 气体 +V 固体 Similarly, the term "solids volume fraction" refers to the ratio (Vsolids) between the volume of solids and the volume of liquid, gas, and solids in a fibrous foam. 固体 / (V) 液体 +V 气体 +V solid).

[0119] In this context, liquid (V) 液体 The volume of a liquid can be determined using standard calibrated volumetric instruments, such as pipettes, droppers, graduated cylinders, and volumetric flasks. These instruments can be used to measure the volume of liquids with high precision and accuracy. Such instruments can be calibrated according to ISO 4787:2021.

[0120] Fiber volume (V) 纤维 Fiber density is defined as the ratio of fiber mass to fiber density. Fiber density—that is, the density of a porous or internally void solid—can be determined using, for example, the gas density determination method described in ISO 12154:2014. That is, the volume of the solid is determined by measuring the pressure change when a known volume of gas is displaced by the solid in a closed chamber. Fiber density can be calculated as the ratio of mass to the volume of gas displaced. Typical fiber densities in this manufacturing method are 0.90 to 1.80 g / cm³. 3 (For example, spruce kraft paper: 1.5g / cm³) 3 Eucalyptus kraft paper: 1.5g / cm3, monocellulose: 1.5g / cm3 3 Flax: 1.43-1.52 g / cm³ 3 Hemp: 1.47-1.50 g / cm³ 3 Viscose fiber: 1.52 g / cm³ 3 Nylon 6.6: 1.14 g / cm³ 3 Polyester: 1.38 g / cm³ 3 Polypropylene: 0.90 g / cm³ 3 ).

[0121] Volume of solid (V) 固体 Volume {i} is defined as the sum of the volumes of each solid {i} present in the fibrous foam. Volume {i} can be defined as the ratio between the mass and density of solid {i}. The density of the solid can be determined as follows: - The density of a solid with a regular shape and measurable by a ruler or caliper can be determined by direct measurement of its mass and volume. The mass can be measured using a balance, and the volume can be calculated from the dimensions. Density is then the ratio of mass to volume. - The density of a solid with an irregular shape that cannot be directly measured can be determined using indirect volumetric measurement. The volume can be determined by displacing a known amount of liquid or gas with the solid and measuring the difference. Density is then the ratio of mass to the displaced volume. The density of insoluble and non-porous solids can be determined using hydrostatic weighing. The mass of the solid is measured in air and then in water (or another liquid). The mass difference is equal to the buoyant force exerted by the liquid on the solid. The density is then calculated based on the mass difference and the density of the liquid. The density of porous or internally void solids can be determined using, for example, the gas specific gravity determination method described in standard ISO 12154:2014. The volume of the solid is determined by measuring the pressure change when a known amount of gas is displaced by the solid in a closed chamber. The density is then the ratio of its mass to the volume of gas displaced.

[0122] Volume of gas (V) 气体 This can be determined by measuring the gas content of the fibrous foam. (In measuring V...) 液体 V 纤维 and V 固体 Then, the initial volume of the liquid before foaming can be calculated as the sum of all these volumes. After foaming, the volume (V) of the fibrous foam 纤维性泡沫 The volumetric volume can be determined using standard calibration instruments such as pipettes, droppers, graduated cylinders, and volumetric flasks. These instruments can be used to measure the volume of foam with high precision and accuracy. Such instruments can be calibrated according to ISO 4787:2021.

[0123] - The gas content in fibrous foam can be calculated as follows: Gas content = 1 - (V) 液体 +V 固体 ) / V 纤维性泡沫 - Then the volume of the gas (V) can be determined. 气体 The calculation is as follows: V 气体 = Gas content * (V) 液体 +V 固体 ) / (1-solid content) As used herein, the term "liquid slurry" refers to a liquid-solid suspension or mixture of chemical components. Liquid slurries can be generated, for example, from liquids and solids in contact within a reactor or mixer. Liquid slurries can provide benefits such as better handling of solids in the slurry and the attainment of certain chemical reactions or physical interactions, such as the capture of aromas from solids in the liquid.

[0124] As used herein, the term "fiber" refers to an elongated solid object having an apparent length (i.e., an aspect ratio of at least about 5 or at least about 10) that greatly exceeds its apparent width. Fibers are typically considered to be discontinuous in nature. Non-limiting examples of fibers include pulp fibers such as wood pulp fibers or ring-shaped plant fibers or synthetic short fibers such as viscose and polylactic acid (PLA) fibers. Fibers can be monocomponent or multicomponent, such as bicomponent fibers. As used herein, fibers can be those generally suitable for methods of producing absorbent web-based products, and particularly suitable for methods of manufacturing tissue paper or nonwoven fabrics.

[0125] The term "cellulose fiber" (also known as "wood pulp fiber," "ringed plant pulp fiber," or "non-wood fiber") refers to fibers composed of or derived from cellulose. Applicable wood pulps include chemical pulps such as kraft pulp, sulfite pulp, soda pulp, and sulfate pulp, as well as mechanical pulps, including, for example, groundwood pulp, thermomechanical pulp, and chemically modified thermomechanical pulp.

[0126] The term "man-made fiber" refers to cellulose or non-cellulose (e.g., thermoplastic) fibers. Thus, the term "man-made fiber" encompasses both "synthetic fibers" and "semi-synthetic fibers" made from natural sources such as rayon.

[0127] As used herein, the term "hardwood fiber" refers to fibers derived from the lignin of deciduous trees (angiosperms). Typically, hardwood fibers are short fibers with an average length of 0.5 mm to 2 mm, a diameter of 15 μm to 30 μm, and a wall thickness of 2 μm to 3 μm. Hardwood fibers are typically pulped using the sulfite process or the kraft paper process.

[0128] As used herein, the term "cork fiber" refers to fibers derived from the lignin of coniferous trees (gymnosperms). Typically, cork fibers are "long" fibers with an average length of 1.2 to 4 mm, a diameter of 30 to 40 μm, and a wall thickness of 3 to 4 μm. Cork fibers are typically pulped using the kraft paper process.

[0129] As used herein, the term "non-wood fiber" refers to fibrous pulp derived from non-woody substances from plants such as cotton, bagasse, hemp, miscanthus, sisal, rice straw, flax, or other plants.

[0130] As used herein, the term "natural cellulose fiber" can be specifically understood as the fibers covering the seeds, such as cotton, kapok, or milkweed; leaf fibers, such as sisal, Manila hemp, pineapple, or New Zealand hemp; and bast fibers, such as flax, hemp, jute, or kenaf. In addition to fibers derived from waste materials such as bagasse and straw, natural cellulose fibers can also originate from a variety of natural sources.

[0131] As used herein, the term "unrefined fiber" characterizes fibers as either naturally occurring or obtained through their respective preparation methods (chemical or mechanical pulping, recycling, etc.). While depending on the fiber source, unrefined hardwood and softwood pulp fibers typically have a Schopper Riegler freeness value of approximately 12 to 15°SRV (where "SRV" stands for "Schopper Riegler (freeness value)"). Unrefined non-wood pulp fibers (from pulp mills) can have SR values ​​ranging from 12 to 70°SRV.

[0132] As used herein, the term "refined fiber" refers to fiber that has undergone a refining process. These methods are well known to those skilled in the art. Refined fibers typically have a degree of freeness value greater than 15 SRV to 75 SRV.

[0133] As used herein, the term "primary pulp fiber" refers to fibers obtained from pulping processes of woody materials (e.g., hardwood, softwood) and non-woody materials (e.g., cotton, bagasse, hemp, miscanthus, etc.) that have not previously been used in manufacturing processes.

[0134] As used herein, the term "secondary pulp fiber" refers to fibers that have been previously used in manufacturing processes (e.g., papermaking or tissue paper manufacturing) and have been recycled (recirculated) as raw materials for the manufacturing methods of this disclosure. Secondary pulp fibers can be recycled from, for example, waste paper, paperboard, or corrugated board using techniques commonly used in the art.

[0135] As used herein, the term "fiber length" characterizes the average length weighted by fiber length (Lpl), which is determined by a technician using a MorFi LB01 device (laboratory equipment). According to the test procedure, pulp samples are treated with an impregnation liquid to ensure the absence of fiber bundles or debris. Each pulp sample is disintegrated in hot water and diluted to approximately 0.001% solution. When tested using the standard MorFi fiber analysis test procedure, individual test samples are drawn from the diluted solution in portions of approximately 50 to 100 ml. The average length weighted by fiber length (Lpl) can be expressed by the following equation: in, L i It is the length of a single fiber, and n is the total number of fibers measured.

[0136] As used herein, the term "rheology modifier" characterizes a substance that can alter the viscosity of a medium mixed with it, particularly by increasing its viscosity. Examples of rheology modifiers include, but are not limited to, cellulose ethers such as sodium hydroxyethyl cellulose (HEC) and sodium carboxymethyl cellulose (CMC), hydrophilic polymers such as polyvinyl alcohol and polyethylene oxide, and polyamides.

[0137] As used herein, the term "slip agent" characterizes a substance that can reduce the friction and stickiness of fibrous foams during preparation steps and subsequent process steps. Examples of slip agents include, but are not limited to, polyols such as glycerol, ethylene glycol, and propylene glycol, as well as polyether polyols.

[0138] As used herein, the term “discharge” refers to a reduction in liquid content, i.e., the extraction of liquid. In particular, it encompasses a reduction in water content. Discharge may also be referred to as deliquescenting, and when water is discharged (mostly or only), it is called dehydration. The term “discharge” specifically covers mechanical techniques for reducing liquid content, rather than drying, which is considered a form of thermal reduction in liquid content.

[0139] As used herein, the term "defibrillation" refers to a method of separating a group or bundle of fibers into at least 65%, optionally 70% or 75%, individual fibers. In particular, defibrillation involves mechanical techniques that generate shear forces, such as hammer milling.

[0140] As used herein, the term "antiflocculation" refers to the process of deflocculating fibers in a slurry or foam (fibrous foam) from a flocculated state to convert them into individual fibers. This specifically includes dispersing and / or maintaining them in a dispersed state. In particular, antiflocculation can be promoted by adding an antiflocculating agent to the substance to be antiflocculated, such as an electrolyte source liquid or powder, such as small amounts of sodium silicate, Darvan, or Displex. The antiflocculating agent can impart a charge to the flocculated particle aggregates, thereby creating a repulsive force between these particles that drives them apart.

[0141] As used herein, the term "hammer mill" refers to a method of crushing and / or crushing material into smaller fragments using a mill (also known as a hammer mill) by repeatedly blowing small amounts of hammers. A hammer mill may include a drum (e.g., a steel drum) containing a vertical or horizontal rotating shaft or roller on which hammers are mounted. The hammers swing freely at the ends of a cross or are fixed to a central rotor. The rotor rotates at high speed inside the drum while material is fed into a feed hopper. The material is impacted by the hammers, defiberized, and discharged through a screen in a drum of selected size.

[0142] As used herein, the term "refining" refers to the mechanical treatment of materials containing fibers that alters, in particular, the properties of the fibers. For example, refining can include fibrillation, which involves exposing fibrils to increase their surface area, thereby improving fiber-fiber bonding. Refining can be particularly useful for increasing the strength of fiber-fiber bonds by increasing the surface area of ​​the fibers and making them more flexible to conform to each other. This can increase the bonded surface area and can result in a denser final product.

[0143] As used herein, the terms “headbox” or “compression mold” refer to a device that distributes (or is configured to distribute) a continuous flow of slurry (e.g., a suspension of solids in a fluid such as water) and / or foam and / or fibrous foam to a machine at a constant rate and / or constant velocity, or to a device that delays (or is configured to delay) the flow rate, such as a top feed filter, or for removing some of the finest particles by overflow.

[0144] A headbox is specifically a headbox assembly that allows slurry to flow through it. Headboxes can particularly and progressively improve the uniformity, stability, and cleanliness of the slurry, and can reduce turbulence of the slurry during its flow through the headbox.

[0145] As used herein, the term "cylindrical die former" refers to a forming apparatus comprising a rotating cylinder covered with a mesh partially immersed in a fiber slurry bath, the rotating cylinder being configured to rotate within the cylindrical bath. The mesh covering the rotating cylinder may comprise two wires of different meshes. The inner wire (also called the backing wire) serves as a support base for the top wire (also called the facing wire) and is typically about 10 to 15 mesh. The top wire is typically about 35 or 80 mesh. The rotating roller is configured to drain water through the wire cloth, leaving fibrous deposits on its surface. Cylindrical die formers can promote random distribution of fibers and can promote high consistency. Cylindrical die diameters are typically in the range of up to about 2000 mm, and cylindrical die faces are in the range of up to about 5500 mm. Operating speeds can range from about 100 to 400 m / min.

[0146] As used herein, the term "breast suction roll former" characterizes a type of former used in cotton paper and papermaking machines. This former includes: a headbox for distributing fiber suspensions or fibrous foams and for ensuring uniform fiber distribution in a planar fiber-containing layer; a forming filament for receiving, transporting, and discharging the fiber suspensions or fibrous foams; and a vacuum-supported breast suction roll for initiating and controlling web formation and web discharge.

[0147] The term "sucking roll forming device" also includes other embodiments of forming devices for tissue paper and papermaking machines, such as sucking roll forming devices that include solid sucking rolls and any type of forming device for wire papermaking machines, as well as forming devices that include cylindrical sleeves or forming cylinders, such as forming devices for cylindrical papermaking machines, or suction forming cylinder forming devices, etc.

[0148] As used herein, the term "positive displacement pump" refers to a device configured to add energy to a fluid by applying force to it using a mechanical device such as a piston or plunger. A positive displacement pump can reduce the volume containing the liquid until the resulting liquid pressure equals the pressure in the discharge system. This increases the potential energy. The displacement pump mentioned herein can be a rotary pump, a blow-molded pump, or a reciprocating pump, as well as combinations thereof. In particular, positive displacement pumps encompass steam pumps, power pumps, controlled positive displacement pumps, vane pumps, piston pumps, flexible component pumps, cam pumps, gear pumps, circumferential piston pumps, and screw pumps.

[0149] Unless otherwise stated, all percentages and ratios are by weight.

[0150] 2. Methods for manufacturing absorbent web-based products One aspect of this disclosure relates to a method for manufacturing absorbent web-based products.

[0151] 2.1 Preparation of fibrous foam In one embodiment, the method includes the step of preparing a fibrous foam. In one embodiment, preparation may include supplying fibers, one or more surfactants, a liquid, and a gas, wherein the fiber content is 5% to 60% by weight, the surfactant content is 0.02% to 1.20% by weight, the liquid content is 40% to 95% by weight, and the gas content is 64% or more by volume. The liquid may be water or may include water. The gas may be air, or may include air and other gases, such as nitrogen or carbon dioxide. The fiber content, surfactant content, and liquid content are based on the total weight of the fibrous foam. The gas content is based on the total volume of the fibrous foam.

[0152] The liquid and / or foam supplied for preparation in which surfactants, fibers and gases are dispersed may contain at least 80% water by weight. It may contain at least 85%, at least 87%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, or at least 95% water by weight.

[0153] The gas to be dispersed in the liquid and / or foam may include at least 95% air by volume. It may include at least 96%, at least 97%, at least 98%, at least 99%, at least 99.2%, at least 99.3%, at least 99.4%, or at least 99.5% by volume.

[0154] The dispersion of gas in a liquid and / or foam (with or after dispersion of fibers and surfactants) results in a gas-liquid dispersion. The gas-liquid dispersion may have a liquid content of at least 80% water by weight and / or a gas content of at least 95% air by volume. The liquid content, by weight of water, may be at least 85%, at least 87%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, or at least 95%.

[0155] A gas content of 64% or more, and for example, an air content of 64% or more, is where the clogging transition occurs between the bubble-liquid and wet foam (volume % based on the total volume of the fibrous foam). Therefore, the fibrous foam can be wet foam. Alternatively, the fibrous foam can be dry foam. Dry foam can have a gas content of 95% or more. A gas content of 64% or more provides suitable properties for the fibrous foam, particularly in terms of rheology, thereby promoting uniform formation and transport of the fibrous foam. A gas content of 64% or more (above the clogging transition) helps prevent fiber flocculation (despite high fiber consistency) and provides associated yield stress and stability to the fibrous foam.

[0156] Fiber-like foams can be prepared to have a lower shear rate of 0.01 s⁻¹ according to the lower curve method. -1 Viscosity in the range of 50 to 2000 Pa·s at shear rates (as described in Section 2.f below) and storage modulus in the range of 400 to 2500 Pa in the linear viscoelastic region (as described in Section 2.f below).

[0157] The fibrous foam can then be formed into a foam layer having a lower shear rate of 0.01 s according to the lower curve method. -1 Viscosity in the range of 50 to 3000 Pa·s at shear rates (as described in Section 2.f) and storage modulus in the range of 500 to 10000 Pa in the linear viscoelastic region (as described in Section 2.f).

[0158] The gas content of the fibrous foam can be 70% or more, 75% or more, or particularly 80% or more, 85% or more, 90% or more, or 92% or more (volume % based on the total volume of the fibrous foam). Fiber foams with a gas content of 80% or more are particularly suitable for this manufacturing method.

[0159] In one respect, the prepared fibrous foam is stable. In this context, "foam stability" refers to the time it takes for the foam to maintain its initial properties (such as gas content and / or rheological properties) at the time of its formation. Foam stability can be expressed as "half-life," which is the time required for half the volume of liquid contained in the foam to return to the bulk liquid phase.

[0160] The fibrous foam disclosed herein may have a half-life of 2 minutes or more, or 3 minutes or more, or 4 minutes or more, or 5 minutes or more. The half-life of the fibrous foam may be determined by: (1) obtaining a sample of the fibrous foam and measuring its gas content to determine the liquid volume of the fibrous foam; (2) pouring 1 L of the fibrous foam into a graduated cylinder and starting a timer; (3) stopping the timer when half of the liquid volume has been discharged to the bottom of the graduated cylinder and reporting this time as the half-life of the fibrous foam. This measurement is performed in a conditioned laboratory (23°C, 50% relative humidity).

[0161] Foam or fibrous foam can be prepared by any method capable of trapping gas in a liquid, including, for example, chemical foaming, injection of pressurized gas, and / or mechanical mixing. Foam or fibrous foam can be prepared using, for example, high-consistency mixing equipment. Non-limiting examples of suitable mixing equipment include the Pico-mix (available from Hansa Industries-Mixer GmbH, Germany), the Lamort mixer (available from Kadant Inc.), or the paddle mixer (available from Forberg International AS). Depending on the type of mixer, the rotor, and the desired foam characteristics, the mixer can be operated at speeds of 100 rpm or more, or 200 rpm or more, and 5000 rpm or less, or 2000 rpm or less, or 1000 rpm or less, particularly 600 rpm or less.

[0162] The prepared liquid phase can have a viscosity of 1 to 500 centipoise (cP), or 5 to 400 cP, or 10 to 250 cP (23°C, 50% relative humidity), where 1 cP = 1 mPa·s. The viscosity can be determined using a Brookfield viscometer (operating conditions: V60 or V12, spindle 61).

[0163] The preparation may include supplying fibers. The fibers may be supplied substantially alone, as obtained through suitable chemical and / or mechanical pretreatment, such as pretreatment with a debinding agent or CMC for fluff pulp and / or hammer milling. The supplied fibers may be dry or may be pretreated with a liquid (e.g., water) (e.g., pre-wetting and / or fluffing pretreated with CMC or another suitable reagent) such that the liquid content of the supplied fibers is up to 80% by weight, or up to 60% by weight, such as about 40% by weight, based on the total weight of the (pretreated) fibers.

[0164] The preparation of fibrous foam may include pre-wetting fibers and optionally mixing them with a paddle mixer until a solid content in the range of 30% to 50% by weight is achieved to form pre-wetted fibers, the solid content being based on the total weight of the pre-wetted fibers.

[0165] Based on the total weight of the fibrous foam, the fiber content can be 5% or more by weight, 10% or more by weight, 15% or more by weight, or 20% or more by weight and 60% or less by weight, or 45% or less by weight, or 35% or less by weight, or 30% or less by weight. A fiber content of 5% or more by weight, particularly 10% or more by weight, or greater than 10% by weight, promotes foam stability, uniform formation, and / or desired product properties such as basis weight and density. Additionally, a fiber content of 5% or more by weight results in less discharge (e.g., dehydration) and / or drying of the fibrous web, thereby promoting energy efficiency in the manufacturing process. A fiber content greater than 60% by weight may be undesirable as it may promote flocculation or cause clogging problems in the machine.

[0166] The supplied fibers can be natural fibers and / or man-made fibers. In particular, the fibers can comprise pulp fibers, including but not limited to chemically pulped fibers, mechanically processed fibers that have undergone chemical pretreatment, and mixtures thereof. In this context, the term "chemical pulp" refers to a fibrous material obtained from plant material in which most of the non-cellulose components have been removed from the plant material through chemical pulping without substantial mechanical post-treatment (according to DIN 6730). When a mixture of natural and man-made fibers is supplied, it may be expected, based on the total weight of the supplied fibers, that at least 25%, 50%, 80%, 90%, or 95% by weight of the fibers are natural fibers. In one aspect, the supplied fibers can be purely natural fibers or purely man-made fibers. The supplied fibers can be purely cellulose-based fibers to produce recyclable absorbent products. This can promote sustainability.

[0167] "Natural fiber" can be any wood fiber and / or non-wood fiber commonly used in papermaking. Natural fiber can be derived from multiple natural sources. Fiber can be pulp fiber obtained through any suitable pulping process. In particular, pulp fiber can be obtained through, for example, kraft paper pulping, soda pulping, sulfite pulping, chemical pulping, chemimechanical pulping (CMP), thermomechanical pulping (TMP), chemithermomechanical pulping (CTMP), bleached chemithermomechanical pulping (BCTMP), or pressure / pressure thermomechanical pulping (PTMP). Considering the production and process steps of environmentally friendly products, pulp fiber can be bleached by using a chlorine-free bleaching step. In one aspect, pulp fiber is obtained through soda pulping or CTMP processes as described by Cappelletto et al. in Industrial Crop and Products, 11 (2000) 205-210.

[0168] Wood pulp fibers can be milled wood pulp fibers. In one aspect, wood pulp fibers can be selected from pulp fibers comprising hardwood fibers (such as eucalyptus, beech, poplar, gum arabic, or birch fibers) and softwood fibers (such as pine, spruce, red cedar, Douglas fir, hemlock, or pine fibers). Particularly useful softwood fibers in this method are Northern Bleached Softwood Kraft Paper (NBSK) fibers. Wood pulp fibers can be a mixture of pulp fibers comprising hardwood and softwood fibers. In one aspect, the weight ratio of hardwood fibers to softwood fibers can be 80 / 20 to 0 / 100, or 50 / 50 to 0 / 100, or 30 / 70 to 0 / 100. Softwood fibers can contribute to desired strength and / or rheological properties, while hardwood fibers can contribute to achieving good softness.

[0169] Wood pulp fibers may be refined or unrefined. In one aspect, at least a portion of the cork fiber to be used is refined and / or at least a portion of the hardwood fiber to be used is unrefined. Cork fibers may be refined to a freeness of 19 to 35°SRV, particularly 19 to 26°SRV, such as 19 to 24°SRV. In one aspect, hardwood pulp fibers are derived from eucalyptus and / or cork pulp fibers are Northern Bleached Cork Kraft Paper (NBSK) fibers, wherein the NBSK fibers are optionally refined to a freeness of 19 to 35°SRV, particularly 19 to 26°SRV, such as 19 to 24°SRV.

[0170] Non-wood fibers can be selected from cotton, bagasse, hemp, miscanthus, sisal, rice straw, and flax fibers. Non-wood fibers can be refined or unrefined. Non-wood fibers can be bleached or unbleached.

[0171] The pulp fibers used in this manufacturing method can be primary fibrous materials (e.g., cork, hardwood, or non-wood fibers such as straw or bagasse), secondary fibrous materials (i.e., fibrous materials containing secondary pulp fibers), and mixtures thereof. In one aspect, (i) all fibers present in the cotton paper web are primary pulp fibers, or (ii) a mixture of primary and secondary (recycled) pulp fibers.

[0172] Man-made fibers can be cellulose fibers and / or non-cellulose fibers. Man-made fibers can be any fiber used to manufacture a substrate and formed through appropriate techniques such as spinning.

[0173] Cellulose synthetic fibers can be selected from: - Regenerated cellulose, such as rayon, viscose, lyocell, cellulose acetate, and other cellulose-derived fibers, and - Modified fibers, such as modified southern pine fiber (for example, sold under the trade name Helix fiber).

[0174] Regenerated cellulose can be obtained by converting natural cellulose into a soluble cellulose derivative and then regenerating the cellulose, typically forming fibers or filaments. The use of cellulose-based synthetic fibers helps to provide bio-based, sustainable products. Examples of regenerated cellulose suitable for manufacturing processes include, but are not limited to, lyocell, Tencel, Neocell, seaweed fiber, and Excel fiber.

[0175] In one respect, cellulose synthetic fibers are not chemically modified. Examples of unmodified cellulose synthetic fibers include viscose and lyocell. Using unmodified cellulose filaments formed from natural cellulose further contributes to providing plastic-free products. Synthetic cellulose fibers can include a variety of fiber types.

[0176] Non-cellulose synthetic fibers can be selected from polyesters (e.g., polyalkylene terephthalate (PET), polybutylene terephthalate (PBT), (bio-based) polylactic acid (PLA), polybutylene succinate (PBS), polybutylene succinate-co-butylene adipate (PBSA), polyhydroxyalkanoates (PHA) and the like), polyolefins (e.g., polyethylene, polypropylene and the like), polyamides (e.g., nylon, such as nylon-6, nylon-6, 6, nylon 6, 12 and the like), and polyacrylonitrile (PAN).

[0177] In one respect, the supplied fibers may comprise multicomponent or bicomponent fibers, such as fibers with a core / sheath structure, for example, fibers in which the core is made of a first material and the sheath is made of another material. Hutterer et al. (see BioResources 2017, 12(3), 5632-5648) have described examples of useful bicomponent fibers, namely xylan-rich viscose. Further useful fibers include, but are not limited to, polyethylene-polypropylene fibers. Bicomponent fibers can be used to improve the bonding between fibers.

[0178] Natural fibers can have an average fiber length of 0.2 mm to 40 mm, or 0.3 mm to 30 mm, or 0.3 mm to 25 mm, or 0.5 mm to 20 mm, or 0.5 mm to 3 mm. Man-made fibers can have any desired average fiber length. However, man-made fibers can be prepared to have an average fiber length of 0.2 mm to 50 mm, or 0.5 mm to 30 mm, or 1 mm to 25 mm.

[0179] In one aspect, the synthetic fibers can be short fibers cut to a specific length for use in the manufacturing methods of this disclosure. The short fibers can be formed from polyethylene, polypropylene, polyester (e.g., polylactide, polyhydroxyalkanoate), polyamide, or cellulose, preferably from polylactide, polyhydroxyalkanoate, or cellulose, and more preferably from cellulose. Using short fibers formed from polylactide, polyhydroxyalkanoate, or cellulose helps to provide biodegradable and compostable products. The short fibers can also be formed from bio-based polyethylene, bio-based polypropylene, bio-based polyester, or bio-based polyamide. Using short fibers formed from bio-based polyethylene, bio-based polypropylene, bio-based polyester, or bio-based polyamide helps to provide bio-based products. Furthermore, the short fibers can be formed from naturally derived cellulose such as regenerated cellulose (as described above). Using short fibers formed from naturally derived cellulose helps to provide bio-based, sustainable products. The average length of the synthetic short fibers used herein can be 5 to 25 mm, or 5 to 20 mm.

[0180] While the supply of fibers has been mentioned, the preparation steps may more generally include the supply of solids. In other words, the solids include fibers and may include further solids. In this context, the further solids may be selected from other solid materials commonly used in fillers, pigments, and absorbent products. Examples of fillers are clay (or kaolin), calcined clay (or kaolin), ground calcium carbonate (GCC), precipitated calcium carbonate (PCC), titanium dioxide, satin white, zinc oxide, barium sulfate, gypsum, silica, alumina trihydrate, talc, mica, and diatomaceous earth, as well as biological fillers such as wood chips, sawdust, crop husks, etc.

[0181] Based on the total weight of the fibrous foam, the solid content can be from 5% to 60% by weight, and at least 80% of the solids by weight can be fibers. At least 85%, or at least 90%, or at least 95%, 97%, 98%, 99%, or 99.5% of the solids by weight can be fibers. All solids can be fibers.

[0182] The prepared fibrous foam may have a solids content of more than 10% by weight. In particular, the prepared fibrous foam may have a fiber content of more than 10% by weight. This can provide a particularly beneficial consistency for absorbent web-based products.

[0183] Specifically, the solids content can be more than 12% by weight. Specifically, the fiber content can be more than 12% by weight. The increased solids content (or fiber content) can provide a particularly beneficial consistency for absorbent web-based products.

[0184] Solid content (or particularly fiber content) can be more than 14%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24% or 25% by weight. Increased solid content (or fiber content) can provide a particularly beneficial consistency for absorbent web-based products.

[0185] The preparation may include supplying one or more surfactants. There are no particular limitations on the surfactants, as long as they can be used to generate foam. The surfactants (multiple surfactants) can be selected from anionic surfactants, cationic surfactants, amphoteric surfactants, amphoteric surfactants, and nonionic surfactants. The surfactants (multiple surfactants) can be polymer- or protein-based.

[0186] Anionic surfactants (a variety of anionic surfactants) may be selected from anionic sulfates, alkyl ether sulfonates, alkyl aryl sulfonates (e.g., (di)alkyl(di)benzenesulfonic acid, alkylphenol sulfonic acid and the like), alkali metal sulfonates, sulfonated glycerol esters of fatty acids, salts of sulfonated monovalent alcohol esters, metal soaps of fatty acids, amides of aminosulfonic acids (e.g., 2-acrylamido-2-methylpropanesulfonic acid), sulfonated amides of aminosulfonic acids, sulfonated products of fatty acid nitriles, alkali metal alkyl sulfates (e.g., sodium dodecyl sulfate (SDS), sodium lauryl sulfate, sodium lauryl polyoxyethylene ether sulfate), ether sulfates, sulfates of polyoxyethylene alkyl ethers, salts of alkyl naphthyl sulfonic acids, phosphate esters, especially sodium dodecyl phosphate and combinations thereof.

[0187] Cationic surfactants (a variety of cationic surfactants) may be selected from fatty acid amines and amides and their salts (e.g., dodecylamine acetate, tallow fatty acid acetate, dodecylaniline, undecylimidazoline and the like), mono-, di- or tri-carbonylammonium or phosphonium salts, carbonyl carboxyl salts, quaternary ammonium salts (e.g., dioctadecyl dimethyl ammonium chloride, didodecyl dimethyl ammonium chloride, dihexadecyl ammonium chloride and the like), imidazolines, ethoxylated amines, quaternary phospholipids and combinations thereof.

[0188] Amphoteric surfactants (a variety of amphoteric surfactants) may be selected from betaine and mixtures thereof. Examples of amphoteric surfactants include, but are not limited to, cocodimethylcarboxymethyl betaine, cocamidopropyl betaine, lauramide propyl betaine, lauryl betaine, citrate betaine, sodium hydroxymethylglycinate, (carboxymethyl)dimethyl-3-[(1-oxododecyl)amino]propylammonium hydroxide, cocoalkyldimethyl betaine, (carboxymethyl)dihydroxymethylacylammonium hydroxide, cocamidopropyl betaine, (carboxymethyl)dimethyl(octadecyl)ammonium, and combinations thereof.

[0189] The amphoteric surfactant (a variety of amphoteric surfactants) may be selected from sodium acylamphoacetate, sodium acylamphopropionate, disodium acylamphodiacetate, and disodium acylamphodipropionate, wherein the alkyl acyl group may include a C7-C18 alkyl moiety. Examples of amphoteric surfactants include, but are not limited to, sodium lauroylamphoacetate, sodium cocoylamphoacetate, sodium lauroylamphoacetate, sodium cocoylamphoacetate, and combinations thereof.

[0190] Nonionic surfactants (a variety of nonionic surfactants) may be selected from amine oxides, alkyl glucosides, alkyl polyglucosides, polyhydroxy fatty acid amides, alkoxylated mono- and di-fatty acid esters, alkoxylated fatty alcohols, alkoxylated alkylphenols, fatty acid monoglycerides, polyoxyethylene sorbitol, sucrose esters, and combinations thereof. In particular, nonionic surfactants (a variety of nonionic surfactants) may be selected from alkyl glucosides, alkyl polyglucosides, alkoxylated fatty alcohols, and combinations thereof.

[0191] In one respect, nonionic surfactants (various nonionic surfactants) can have the following general formula (1): R 1 -O-(R 2 ) n -H (1) in, R 1 It is a straight-chain or branched hydrocarbon group with 4 to 20 carbon atoms. R2 is a hexose or pentose unit, and n is between 1 and 5.

[0192] In general formula (1), R1 It can be a straight-chain or branched hydrocarbon group having 6 to 18 carbon atoms, or 8 to 16 carbon atoms, especially 10 carbon atoms. R 1 It can be expressed as -(CH2) n′ A straight-chain hydrocarbon group of -CH3, wherein n′ is 3 to 19, or 5 to 17, or 7 to 15, especially 9. R 2 It can be a hexose unit or a pentose unit. n can be 1 to 4, especially 1 or 2.

[0193] In one respect, nonionic surfactants (various nonionic surfactants) can have the following general formula (2): CH3-(CH2) n′ -O-(R 2 ) n -H (2) in, R 2 It is a hexose unit, and n is 1 or 2.

[0194] A particularly suitable alkyl polyglucan is Simulsol SL10 (available from Seppic, France).

[0195] Based on the total weight of the fibrous foam, the surfactant content can be from 0.02% to 1.20% by weight. In one aspect, the surfactant content can be from 0.05% to 1.0% by weight, or from 0.1% to 0.8% by weight, or from 0.2% to 0.7% by weight. A content of less than 0.02% by weight may not produce foam with sufficient gas (e.g., air) content and / or stability, while a content of more than 1.20% by weight may not be cost-effective.

[0196] In one aspect, the preparation of fibrous foam may include supplying at least one nonionic surfactant or a mixture of surfactants containing at least one nonionic surfactant. The preparation may include supplying only one or more nonionic surfactants. In this context, the at least one nonionic surfactant (or a plurality of nonionic surfactants) may be selected from the group consisting of: amine oxides, alkyl glucosides, alkyl polyglucosides, polyhydroxy fatty acid amides, alkoxylated mono- and di-fatty acid esters, alkoxylated fatty alcohols, alkoxylated alkylphenols, fatty acid monoglycerides, polyoxyethylene sorbitol, and sucrose esters.

[0197] The at least one nonionic surfactant may be selected from alkyl glucosides, alkyl polyglucosides, and alkoxylated fatty alcohols. In one aspect, the at least one nonionic surfactant may have the above general formula (1) or the above general formula (2).

[0198] When a mixture of surfactants is used, the at least one nonionic surfactant may be contained in an amount of at least 50%, at least 75%, at least 90%, or at least 95% by weight, based on the total weight of the mixture.

[0199] The liquid may contain at least 80% water by weight. Alternatively, the liquid may contain at least 85%, 90%, 96%, 97%, 98%, 99%, 99.5%, or at least 99.8% water by weight. Using a large amount of water as the liquid can improve cost efficiency. The liquid may also contain polar solvents other than water, particularly alcohols such as ethanol or isopropanol. Based on the total weight of the supplied liquid, the content of such polar solvents may be 10% or less by weight, particularly 5% or less by weight. The liquid may contain further components, including one or more binders, one or more rheology modifiers, and other additives soluble therein.

[0200] The gas may contain at least 95% air by volume. Alternatively, the gas may contain at least 96%, 97%, 98%, 99%, 99.5%, 99.8%, or at least 99.9% air by volume. Using a large amount of air as the gas can promote cost efficiency.

[0201] In one respect, the gas may comprise nitrogen and / or carbon dioxide. The gas may also be a mixture of air and nitrogen and / or carbon dioxide, wherein the mixture optionally comprises at least 10%, at least 50%, or at least 90% air by volume. Using nitrogen and / or carbon dioxide as the gas can promote foam stability.

[0202] The preparation may include supplying one or more binders. Using one or more binders may facilitate stabilizing the porous structure and / or improving the strength properties of the absorbent product. The binders (multiple binders) that can be used in the manufacturing process are not particularly limited and can be selected from, for example, strength resins commonly used in papermaking. In one aspect, the binders (multiple binders) may be selected from wet strength agents and dry strength agents.

[0203] Wet strength agents (various wet strength agents) can be selected from urea-formaldehyde (UF) resins, melamine-formaldehyde (MF) resins, polyethyleneimine, polyethyleneamine, polyurea-formaldehyde resins, glyoxal-acrylamide resins, and cationic materials obtained by reacting polyalkylene polyamines with polysaccharides such as starch and various natural gums, as well as resins containing 3-hydroxy-nitro-heterocyclic butane ions obtained by reacting nitrogen-containing polymers with epichlorohydrin. Suitable materials are further described in detail in US 3,998,690 and EP1583869 B1. In particular, wet strength agents (various wet strength agents) can be selected from polyaminoamide-epitaphthol resins, polyamide-epitaphthol (PAE) resins, polyamine-epitaphthol resins, and amino polymer-epitaphthol resins. An example of these resins is the commonly used Kymene resin (available from Ashland).

[0204] Dry strength agents (a variety of dry strength agents) can be selected from polycarboxylic acids and anhydrides, such as starch-based polymers, (meth)acrylic acid-derived polymers and copolymers, modified polyacrylamide, sugars, polyvinyl alcohol, copolymers derived from maleic anhydride, vinyl copolymers of carboxylic acids and cellulose-based polymers. Cellulose ethers, especially carboxyalkylated polysaccharides and carboxyalkylated cellulose derivatives, are particularly suitable for this method.

[0205] Cellulose ethers include carboxymethyl cellulose (CMC), methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), methylethyl cellulose (MEC), hydroxyethyl methyl cellulose (HEMC), hydroxypropyl methyl cellulose (HPMC), guar gum, locust bean gum, carboxymethyl starch and the like, as well as their alkali metal or ammonium salts. Sodium carboxymethyl cellulose (CMC) is particularly suitable for this method.

[0206] In one aspect, binders (multiple binders), such as polysaccharides like CMC and modified starch, can also be used to modify the rheological properties of fibrous foams, particularly increasing viscosity. In this case, it should be understood that the binders (multiple binders) can be used alone or in combination with one or more other rheology modifiers (described further below). In one aspect, the fibrous foam contains one or more binders (e.g., CMC) and is substantially free of other rheology modifiers. In this context, the term "substantially free of" means that other rheology modifiers are not supplied or are supplied such that their content is less than 0.05% or less than 0.02% by weight based on the total weight of the fibrous foam.

[0207] Based on the total weight of the supplied fibers, the content of the binder (multiple binders) (if present) as described above may be 0.005% to 30% by weight, or 0.01% to 28% by weight, or 0.05% to 25% by weight, or 0.10% to 20% by weight, or 0.10% to 15% by weight.

[0208] Additionally, the binder (multiple binders) may be selected from latex, such as anionic styrene-butadiene copolymer, anionic styrene-butadiene copolymer, polyvinyl acetate homopolymer, vinyl acetate-ethylene copolymer, vinyl acetate-acrylic copolymer, ethylene-vinyl chloride copolymer, ethylene-vinyl chloride-vinyl acetate terpolymer, acrylic-polyvinyl chloride polymer, acrylic polymer, nitrile polymer, and combinations thereof. The latex (multiple latexes) content (if present) may be from 5.0% to 20.0% by weight, or from 10.0% to 15.0% by weight, based on the total weight of the supplied fibers.

[0209] In one aspect, the binder (of various types) may be selected from microfibrillated cellulose (MFC) fibers, nanofibrillated cellulose (NFC) fibers, and mixtures thereof. Using MFC and / or NFC fibers as binders can promote desired strength and tactile properties. Based on the total weight of the supplied fibers, the content of MFC / NFC fibers (if present) may be from 0.5% to 20.0% by weight, or from 0.8% to 10.0% by weight, or from 1.0% to 5.0% by weight.

[0210] The preparation may include supplying one or more rheology modifiers. Rheology modifiers (multiple rheology modifiers) can be particularly useful for defiberizing fibrous materials and / or achieving desired rheological properties for formation. Rheology modifiers (multiple rheology modifiers) may be selected from water-soluble substances commonly used in papermaking, including but not limited to cellulose ethers such as hydroxyethyl cellulose (HEC) and sodium carboxymethyl cellulose, hydrophilic polymers such as polyvinyl alcohol and polyethylene oxide, polyamides, and combinations thereof. In this context, the term "water-soluble" means a solubility in water of at least 40 g / L, or at least 200 g / L, particularly 500 g / L, at 25°C. Cellulose ethers such as sodium carboxymethyl cellulose (e.g., available under the trade name Carbocell) are particularly suitable for this method.

[0211] In one aspect, one or more rheology modifiers supplied have a viscosity of 10 to 2,500,000 cP, or 100 to 140,000 cP, or 200 to 12,000 cP, or 300 to 6,500 cP, or 700 to 3,000 cP, or 750 to 2,500 cP, or 800 to 2,000 cP, or 800 to 1,500 cP (as measured using a Brookfield viscometer and a 1% aqueous solution at 25°C).

[0212] The content of the rheology modifier (a variety of rheology modifiers) (if present) may be 0.001% to 10% by weight, or 0.001% to 5% by weight, or 0.001% to 2% by weight, or 0.001% to 1% by weight, or 0.001% to 0.5% by weight, or 0.001% to 0.25% by weight, or 0.001% to 0.15% by weight, or 0.001% to 0.1% by weight, or 0.001% to 0.05% by weight, based on the total weight of the supplied fibers.

[0213] The preparation may include supplying one or more slip agents. In the preparation and subsequent method steps, the slip agent (or multiple slip agents) may help reduce the friction and stickiness of the fibrous foam. The slip agent (or multiple slip agents) may be selected from polyols such as glycerol, ethylene glycol and propylene glycol, polyether polyols, and combinations thereof.

[0214] In one aspect, the slip agent (multiple slip agents) can be a polyether polyol selected from polyethylene glycol, polypropylene glycol, and combinations thereof. In particular, the slip agent (multiple slip agents) can be polyethylene glycol, which optionally has a number average molecular weight of 100 to 1,000,000, or 500 to 500,000, or 800 to 250,000, or 1,000 to 20,000, or 1,500 to 10,000, as determined by suitable techniques such as gel permeation chromatography (GPC).

[0215] Based on the total weight of the supplied fibers, the content of the slip agent (multiple slip agents, if present) may be 0.001% to 10% by weight, or 0.001% to 5% by weight, or 0.001% to 2% by weight, or 0.001% to 1% by weight, or 0.001% to 0.75% by weight, or 0.001% to 0.5% by weight, or 0.001% to 0.3% by weight, or 0.001% to 0.2% by weight, or 0.001% to 0.15% by weight, or 0.001% to 0.10% by weight.

[0216] The preparation may include the supply of one or more additives. Additives may be selected from softeners, debinding agents, retention agents, pH modifiers for expanded microcapsules (e.g., Expansion microspheres), colorants, dyes, and the like. In this context, it should be understood that the additives (multiple additives) are soluble and / or dispersible in a liquid and are distinct from the solids described above. The content of the additives (multiple additives) (if present) may be 0.001% to 0.5%, 0.001% to 0.3%, 0.001% to 0.2%, or 0.005% to 0.18%, or 0.01% to 0.15%, or 0.01% to 0.10% by weight, based on the total weight of the supplied fibers.

[0217] In one embodiment, the method includes the step of preparing a fibrous foam comprising fibers, a liquid, and a gas, wherein the fiber volume fraction is 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less. The liquid may be water, or may contain water. The gas may be air, or may contain air.

[0218] Although fibers have been mentioned, the fibrous foam prepared may more generally contain solids, and the solid volume fraction may be 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less.

[0219] The solids may contain at least 80% by weight of fibers. Alternatively, at least 85%, or at least 90%, or at least 95%, 97%, 98%, 99%, or 99.5% by weight of fibers may be present. All solids may be fibers. The fiber content may range from 5% to 60% by weight. The liquid content may range from 40% to 95% by weight. The gas content may be 64% or more by volume, optionally at least 70%, at least 75%, or at least 80% by volume.

[0220] The preparation may include supplying a rheology modifier. The rheology modifier can be used to reduce or increase the viscosity of fibrous foams and can promote stability.

[0221] The method may include a step of preparing a liquid slurry prior to the step of preparing fibrous foam, the liquid slurry comprising at least one component selected from the group consisting of liquids such as water, fibers, surfactants, binders, and slip agents.

[0222] The preparation of fibrous foam may include supplying at least one surfactant or a mixture of surfactants. In particular, any one or more surfactants or surfactant types defined in this disclosure may be supplied. Specifically, the surfactant (a variety of surfactants) may be selected from anionic surfactants, cationic surfactants, amphoteric surfactants, amphoteric surfactants, and nonionic surfactants.

[0223] The preparation of fibrous foam may include supplying at least one nonionic surfactant or a mixture of surfactants containing at least one nonionic surfactant, wherein the nonionic surfactant (a variety of nonionic surfactants) is optionally selected from the group consisting of: amine oxides, alkyl glucosides, alkyl polyglucosides, polyhydroxy fatty acid amides, alkoxylated mono- and di-fatty acid esters, alkoxylated fatty alcohols, alkoxylated alkylphenols, fatty acid monoglycerides, polyoxyethylene sorbitol, and sucrose esters.

[0224] The at least one nonionic surfactant may be selected from the group consisting of alkyl glucosides, alkyl polyglucosides and alkoxylated fatty alcohols, wherein the at least one nonionic surfactant may be an alkyl polyglucoside of general formula (1): R 1 -O-(R 2 ) n -H (1) in, R 1 It is a straight-chain or branched hydrocarbon group with 4 to 20 carbon atoms. R 2 It consists of hexose or pentose units, and n is between 1 and 5.

[0225] The preparation of fibrous foam and the transport of fibrous foam to a foam layer forming apparatus can be facilitated by the same mechanical motion. This can particularly improve processing efficiency and / or allow for a reduction in specific energy consumption.

[0226] 2.2 Fibrous foam is formed into a foam layer. This method may include the step of forming a fibrous foam into a foam layer. Forming into a foam layer may particularly involve making the fibrous foam planar. The foam layer has two extension dimensions (two directions of the planar surface) and a thickness dimension, wherein the foam layer is thinner in the thickness dimension compared to the planar extension dimensions.

[0227] The foam layer form may be advantageous in allowing for evaporation, particularly mechanical evaporation, but also in allowing for thermal drying. Furthermore, the foam layer can be considered a step towards a desirable form of absorbent web-based product, which serves as the base material for hygiene products such as tissue-like or nonwoven products.

[0228] Forming fibrous foam into a foam layer may include making the fibrous foam into a planar layer. The planar form can allow for efficient discharge (especially for dehydration).

[0229] The method may include contacting one or more of liquid slurry, foam, solid, liquid and fibrous foam with at least one rotatable device (e.g., a screw) and rotating the at least one rotatable device to transport the fibrous foam.

[0230] The rotation of the at least one rotatable device (e.g., a screw) can enable mechanical discharge / dehydration, or can facilitate discharge / dehydration. The rotation of the at least one rotatable device can also process fibrous foam or facilitate the processing of fibrous foam.

[0231] The at least one rotatable device (e.g., a screw) can rotate at 100 to 5000 rpm or 500 to 3000 rpm, or 800 to 2800 rpm, or 1000 to 2500 rpm, or 1600 to 2400 rpm.

[0232] The rotatable device may consist of a high-shear mixer, and the mixer may operate at a speed of 100 rpm or more. The speed may be 200 rpm or more and 5000 rpm or less, or 200 rpm or more and 2000 rpm or less, or 200 rpm or more and 1000 rpm or less, or 200 rpm or more and 600 rpm or less.

[0233] Forming fibrous foam into foam layers can be performed, at least in part, in one or more of the following devices: compression molding, headbox, and cylindrical die forming device.

[0234] The molding die can be a slot die with an adjustable molding gap. Fibrous foam can be processed into continuous fibrous webs or sheets on a moving continuous dewatering / conveyor unit.

[0235] Forming fibrous foam into a foam layer can include making the fibrous foam planar. A planar form is a form in which one dimension of the foam (orthogonal to the plane of the planar form) is much thinner than the dimension in the planar direction.

[0236] Forming apparatus for performing formation (or being configured to perform formation) may include at least one foam forming section (flow section) to which fibrous foam is attached and flows to form a planar shape. Specifically, the die and / or headbox and / or cylindrical mold may have an outlet opening having a cross-section perpendicular to the flow direction of the fibrous foam and having a major axis and a minor axis, the major axis also referred to herein as the width of the outlet opening, and the minor axis also defined herein as the height of the outlet opening, wherein the ratio between the major axis dimension and the minor axis dimension is in the range of 2 or more, 4 or more, 6 or more, 8 or more, or 9 or more, or 10 or more, or 11, or 12, or 13 or more.

[0237] The forming apparatus may include two or more foam forming sections.

[0238] The short shaft of the outlet opening of the forming device may have a dimension of at least 0.5 mm, or at least 0.8 mm, 0.9 mm, or 1.0 mm. These minimum short shaft dimensions, increasing with increasing minimum value, are suitable for preventing or even avoiding blockage. The outlet short shaft (specifically referred to as the height when the short shaft is oriented along or substantially along the direction of gravity) may be a slit opening. The outlet short shaft dimension may range from 0.5 mm to 5.0 mm, 0.8 mm to 4.0 mm, 0.9 mm to 3.0 mm, or 1.0 mm to 2.5 mm.

[0239] The forming apparatus may include an inlet defined by the width of a cross-section perpendicular to the flow direction of the fibrous foam and having a major axis and a minor axis, the major axis also referred to herein as the width of the outlet opening, and the minor axis also defined herein as the height of the opening. The major axis of the inlet opening may be at least 1.5 times, 2.0 times, 3.0 times, 5.0 times, or 8.0 times larger than the minor axis of the outlet opening.

[0240] The outlet height, or more generally, the opening size (e.g., the dimensions of the cross-section of the outlet surface), can be adapted to the desired foam consistency. The foam consistency, fiber volume fraction, and / or air content can be adapted to achieve the desired target basis weight and / or density of the product. Additionally, the bulk solids volume fraction, and particularly the fiber volume fraction, can also be customized according to the desired basis weight and / or density.

[0241] The forming apparatus may include a lateral diffusion portion shaped to promote lateral diffusion of the foam in order to increase the MD / CD size ratio of the foam.

[0242] The forming apparatus may include or consist of a mold and / or a headbox and / or a cylindrical mold. The forming apparatus may include or consist of multiple molds or headboxes or cylindrical mold forming devices (or combinations thereof).

[0243] The formation of fibrous foam into foam layers can be performed entirely in a forming apparatus, and particularly, for example, in one or more molds and / or one or more headboxes.

[0244] 2.3 Discharge (specifically: dehydration) and drying The method may include the step of discharging fibrous foam from a foam layer to form a fibrous web, wherein the fibrous web has a liquid content of 20% to 85% by weight.

[0245] A liquid content of 20% to 85% in fibrous webs can be considered a significantly low liquid content as a starting point for subsequent drying steps. This allows for reduced specific energy consumption and facilitates achieving the desired level of dryness of the product. For example, the liquid content at the end of the discharge step can be half that encountered in comparable manufacturing methods prior to the drying step. This can allow for savings of up to 80%, and particularly at least 50%, of the energy required for proper drying of the product during subsequent drying steps.

[0246] The liquid content of the fibrous web may be 20% to 85% by weight, or 25% to 85% by weight, or 30% to 80% by weight, or 40% to 80% by weight, or 50% to 80% by weight, or 50% to 75% by weight.

[0247] Discharge of fibrous foam can include mechanical discharge. Mechanical discharge relies on the use of mechanical force to remove the liquid. When the liquid is water (or substantially water), mechanical discharge can also be referred to as mechanical dehydration. Mechanical discharge can be enhanced by raising the temperature of the liquid before mechanical discharge.

[0248] Mechanical discharge allows for a reduction in liquid content, and thus allows for a reduction in specific energy consumption during thermal discharge (particularly thermal dehydration), i.e., for reducing specific energy consumption. This can promote energy conservation and therefore environmental friendliness.

[0249] Dehydration of fibrous foam can include mechanical dehydration. Mechanical dehydration relies on the use of mechanical force to remove water.

[0250] The discharge of fibrous foam can consist of mechanical discharge. Dehydration can consist of mechanical dehydration.

[0251] In this context, dehydration is understood to exclude drying; that is, in this context, dehydration should be considered separate from heat emissions (especially thermal dehydration) in the sense of drying.

[0252] This method may include a drying step of drying fibrous webs to obtain absorbent web-based products. The specific energy consumption of drying can be reduced compared to when relying on conventional manufacturing processes. One reason may be that the liquid content of fibrous webs is significantly lower compared to known intermediate products. Furthermore, drying can reduce the liquid content to the level required for absorbent products.

[0253] Drying may include thermal drying. Drying may include freeze drying. Drying may include infrared drying. Drying may include contact drying. Drying may include shock drying. Drying may include microwave drying. Drying may include ventilated drying. Drying may include any combination of the types of drying described above and repeated drying steps. In contrast to mechanical discharge, drying may be specifically considered as thermal drying.

[0254] A drying step can be performed, and the resulting absorbent web-based product can have a liquid content of 0.5% to 15% by weight. The liquid content can be 1% to 15% by weight. The liquid content can be 1% to 10% by weight. The liquid content can be 1.5% to 8% by weight. The liquid content can be 1.8% to 6.5% by weight. The liquid content can be 2% to 5% by weight. This increasingly narrow range of liquid content may become increasingly beneficial for the absorbency characteristics of absorbent web-based products, as well as for sufficient stability and customer satisfaction in hygiene products including absorbent web-based products.

[0255] Specifically, absorbency-based products can have a water content of 1% to 15% by weight. The water content can specifically be 1% to 10% by weight. The water content can specifically be 1.5% to 8% by weight. The water content can specifically be 1.8% to 6.5% by weight. The water content can specifically be 2% to 5% by weight.

[0256] Discharge may include applying a vacuum to the foam layer at a constant pressure or at a varying pressure. The variation may be temporal or spatial. In other words, the pressure may increase or decrease over time. Alternatively, the pressure may be higher or lower upstream and downstream (i.e., spatial pressure variation).

[0257] The changing pressure can be a pressure that decreases at least once in the downstream direction of transport. The pressure can, for example, decrease and increase successively, or decrease again, etc.

[0258] Discharge can be performed by applying a vacuum to the foam layer in at least two consecutive stages, optionally to reduce the pressure. Between these stages, the pressure may or may not be reduced. In other words, there can be several stages involving both increasing and decreasing pressure.

[0259] 2.4 Processing The preparation steps may include processing liquid slurry or foam and fibers into fibrous foam. In other words, liquid slurry and solids (such as fibers) or foam and solids (such as fibers) can be processed into fibrous foam.

[0260] The processing can be performed at least in part by a transport device that transports the fibrous foam to a forming device that forms the fibrous foam into a foam layer.

[0261] This can provide the benefits of a more space-efficient manufacturing process and can improve process efficiency. When at least a portion of the machining is performed by a transport device, there is no need to provide additional separation devices for the same portion being machined.

[0262] According to some embodiments, the processing can be performed by a transport device.

[0263] This can particularly facilitate manufacturing in a space-efficient manner. Unitized processing and transport allow for the holistic execution of individual steps, such as using a single structural unit. This, in turn, allows for higher processing speeds, as identical procedural steps can facilitate both processing and transport. The fusion of these steps can also reduce specific energy consumption, as the same motion can be used to facilitate different purposes in parallel.

[0264] The device may include a pressurizing device between the transport device and the forming device.

[0265] The processing can be performed by a processing device, and the discharge of fibrous foam can be performed by a discharge device.

[0266] One or more of the following components may be part of an integral structural unit: processing device, conveying device, forming device, and discharging device. The integral structural unit may include any two or any three or all of the listed devices.

[0267] The processing apparatus may include a transport device. The processing apparatus and the transport device can be a single, identical structural unit. This can promote space efficiency regarding the equipment. Furthermore, this integrated construction can also promote higher processing speeds and / or lower specific energy consumption.

[0268] A monolithic construction means that all components belong to the same structural unit, rather than being housed in separate units. This promotes space efficiency in manufacturing equipment. Furthermore, a monolithic construction allows for precise matching of subsequent manufacturing steps, thereby reducing manufacturing time.

[0269] This process may include increasing the pressure applied to the liquid slurry or fibrous foam during transport by a transport device in the downstream transport direction. The increase in pressure can be influenced by changing the transport speed (e.g., by subsequently increasing and decreasing the transport speed, or vice versa).

[0270] The pressure increase or decrease can be, for example, at least 0.1 bar. It can be up to 10 bar. It can be in the range of 0.5 bar to 8 bar. The pressure can be increased once or several times. The pressure can be decreased once or several times. The pressure can be increased and decreased once or several times. Increasing and / or decreasing the pressure can help change the properties of the processed foam.

[0271] The process may include applying multiple different pressure levels in succession in the downstream direction, wherein the pressure level may be reduced two or more times and / or the pressure level may be increased two or more times.

[0272] The increase in pressure may include applying multiple different pressure levels in succession in the downstream direction, with the pressure level increasing at least twice.

[0273] The processing may include at least one of the following: heating, defiberization, anti-flocculation, refining, dispersion, disintegration, alteration of fiber shape, and addition of chemical additives. The above can be achieved by applying shear force, tensile force, and mixing, particularly by applying tensile force.

[0274] The fiber volume fraction in fibrous foam can be specifically controlled by selecting the consistency of one or more types of fibers in the fibrous foam and the air content in the fibrous foam.

[0275] Adjusting the fiber volume fraction can be used to control the properties of fibrous foams, such as viscosity and / or rheology.

[0276] This processing can be specifically used to reduce the fiber volume fraction. Alternatively, processing can be performed to keep the fiber volume fraction more or less the same. Alternatively, processing can be performed to increase the fiber volume fraction.

[0277] 2.5 Transportation Rotation of at least one rotatable device can promote the defibrination of at least a portion, and optionally all, of the fibers. This can be a particularly efficient use of energy to facilitate transport while simultaneously promoting defibrination. This can further improve energy efficiency.

[0278] The fibrous foam can be conveyed by at least one processing device selected from the following list: industrial mixer, screw kneader, industrial kneading machine, extruder, single-screw or twin-screw machine, single-screw or twin-screw continuous kneader, twin-screw or multi-screw machine, conical screw mixer, wherein the at least one processing device includes at least one rotatable device.

[0279] The method may include supplying the fibrous foam with at least one component selected from the following list when the fibrous foam is being transported through a processing device: - A liquid, such as water, which may optionally contain one or more additives; - Gases, such as air; - Foam and / or liquid slurries; and - Solids, such as fibers, powders and / or granules.

[0280] The liquid may be derived, for example, from dispersing the additive in a medium. One or more additives may include additive solutions, liquid additives, and / or additive dispersions.

[0281] The rotation of the at least one rotatable device includes rotating a twin-screw, a single-screw, or a multi-screw.

[0282] Transporting fibrous foam by rotating the at least one rotatable device may include one or more of the following: accelerating the fibrous foam; decelerating the fibrous foam; and applying shear force to the fibrous foam. Applying shear force (or different shear forces) and / or accelerating or decelerating the foam can help modify foam properties, particularly such as viscosity and / or rheology.

[0283] The rotation of the at least one rotatable device is performed in a screw assembly. The screw assembly may include a housing and at least one screw (as an example of a rotatable device).

[0284] In a cross-section perpendicular to the axis of rotation of at least one screw, the minimum distance between at least one screw and the relative inner surface of the housing is in the range of 1% to 20% of the screw's outer diameter, optionally in the range of 0.3 mm to 20 mm.

[0285] At a specific location along its axis of rotation, the outer diameter of the screw should be understood as the diameter of the surface swept by a segment of the rotating screw in a direction perpendicular to the axis of rotation. This outer diameter of the screw may also be referred to as the thread diameter, the major diameter, or the diameter of the rotating surface of the screw.

[0286] The outer diameter of a screw can vary along its axis of rotation, or it can remain constant. An example of a screw with a varying outer diameter is a tapered screw. The minimum distance referred to is the smallest of all minimum distances at different locations along the screw's axis of rotation.

[0287] The outer diameter of the screw can be in the range of 1.5mm to 2000mm, or 2mm to 1500mm, or 4mm to 1000mm, or 5mm to 800mm, or 8mm to 700mm, or 12mm to 500mm, or 15mm to 400mm, or 18mm to 350mm, or 20mm to 300mm, or 20mm to 250mm, or 20mm to 200mm, or 20mm to 150mm, or 20mm to 120mm, or 20mm to 110mm, or 20mm to 100mm.

[0288] The at least one rotatable device may include at least a first screw and a second screw. The first screw and the second screw may be rotatable independently, or rotatable together, or in some embodiments, alternatively rotatable independently or jointly.

[0289] During rotation, the closest approach distance between the first and second screws can range from 0.3 mm to 20 mm. Specifically, the closest approach distance can be within the ranges of 0.35 mm to 20 mm, or 0.4 mm to 15 mm, or 0.45 mm to 12 mm, or 0.5 mm to 10 mm, or 0.7 mm to 7 mm, or 0.8 mm to 5 mm, or 0.9 mm to 3 mm, or 0.93 mm to 2 mm, or 0.95 mm to 1.5 mm. The first and second screws may mesh with each other, or they may not mesh with each other.

[0290] The outer diameter of the first screw can be constant along its axis of rotation, or it can vary along the axis of rotation. Additionally, the closest approach between the first screw and the housing can be constant, or it can vary along the axis of rotation. Similarly, the outer diameter of the second screw can be constant along its axis of rotation, or it can vary along the axis of rotation. The term "closest approach between screw and housing" refers to the distance between the swept surface of the corresponding screw's outer diameter and the opposing surface of the housing. The closest approach distance is the minimum distance among all distances along the corresponding axis of rotation. The term "closest approach between two screws" refers to the minimum distance reached between the two screws when they rotate.

[0291] The at least one rotatable device may include a plurality of screws and at least one housing housing the plurality of screws. The nearest approach distance between any of the plurality of screws and the opposing inner surfaces of the at least one housing housing housing any screw may be in the range of 0.3 mm to 20 mm. The nearest approach distance may be in the range of 0.35 mm to 20 mm, or 0.4 mm to 15 mm, or 0.45 mm to 12 mm, or 0.5 mm to 10 mm, or 0.7 mm to 7 mm, or 0.8 mm to 5 mm, or 0.9 mm to 3 mm, or 0.93 mm to 2 mm, or 0.95 mm to 1.5 mm.

[0292] Before formation, the fibrous foam can be displaced using a displacement pump. The fibrous foam can also be displaced using two or more displacement pumps, particularly positive displacement pumps. Each displacement pump (or, if a single displacement pump is available) can be rotary or reciprocating. Positive displacement pumps can generate high pressure while operating at low suction pressure.

[0293] The displacement generated by one or more displacement pumps can be combined with other types of displacement.

[0294] 2.6 Control Therefore, the method can be controlled to include one or more control units.

[0295] The dispersion of gas in a liquid can be performed using feedback loop control.

[0296] Feedback loop control may include measuring at least one of a gas content, the density of a gas-liquid dispersion, and the conductivity of a gas-liquid dispersion, as well as adding and dispersing the gas until at least one of the gas content, density, and conductivity reaches a target value. Feedback loop control may include measuring and controlling one, two, or three of the aforementioned parameters. Alternatively or in addition to this, feedback loop control may include measuring and controlling one or more different parameters.

[0297] The target value for gas content can be set within the range of 70% or more, 75% or more, 80% or more, 85% or more, or 90% or more by volume of the gas-liquid dispersion.

[0298] The target density value can be set between 3 and 550 kg / m³. 3 or 4 to 355 kg / m 3 or 5 to 300 kg / m 3 or 6 to 180 kg / m 3 or 7 to 150 kg / m 3 or 7 to 130 kg / m 3 Or 8 to 110 kg / m 3 or 9 to 90 kg / m3 or 9.5 to 75 kg / m 3 Within the range.

[0299] The target value for conductivity can be set in the range of 0 to 5000 µS / cm, or 100 to 4000 µS / cm, or 500 to 3500 µS / cm, or 1000 to 3000 µS / cm.

[0300] The preparation may include supplying gas and liquid into a container such that the volume ratio between the amount of liquid supplied and the amount of gas supplied is within a predetermined range or reaches a predetermined value.

[0301] The predetermined volume ratio can be in the range of 0.002 to 0.55, or 0.005 to 0.43, or 0.01 to 0.33, or 0.018 to 0.25, or 0.025 to 0.18, or 0.033 to 0.14.

[0302] Preparation may include supplying gas and liquid into a container such that the density of the gas-liquid dispersion is within a predetermined range or reaches a predetermined value.

[0303] The preset range can be set from 3 to 550 kg / m 3 or 4 to 355 kg / m 3 or 5 to 300 kg / m 3 or 6 to 180 kg / m 3 or 7 to 150 kg / m 3 or 7 to 130 kg / m 3 Or 8 to 110 kg / m 3 or 9 to 90 kg / m 3 or 9.5 to 75 kg / m 3 Within the range.

[0304] Preparation may include mechanically mixing in a container for at least a predetermined time or until foam parameters (such as foam height and / or gas content) reach a predetermined minimum threshold.

[0305] The predetermined minimum threshold for foam height can be set according to the geometry of the fibrous foam preparation device.

[0306] The predetermined minimum threshold for gas content can be set to at least 70%, 75%, 80%, 85%, 90%, 93%, 95%, or 96% by volume.

[0307] 2.7 Manufacturing of the final product This disclosure also relates to the manufacture of a final product, wherein the manufacture includes the steps of manufacturing an absorbent web-based product according to any one or more aspects described in this disclosure.

[0308] The absorbent web-based products manufactured are particularly prone to wrinkling. Wrinkling is a process that can be applied to sheets of absorbent web-based materials to create a cracked, three-dimensional texture.

[0309] Wrinkling can include rotating pressure vessels heated by steam using Yankee drying cylinders (Yankee dryers). The Yankee drying cylinder may comprise a steam-heated rotating pressure vessel (e.g., rotating at a circumferential speed between 1 m / s and 50 m / s, or 2 m / s to 45 m / s, or 5 m / s to 45 m / s, or 10 m / s to 40 m / s, or 20 m / s to 35 m / s), and having a diameter, for example, between 0.5 m and 8 m, optionally between 0.7 m and 6 m, or 0.8 m and 5 m, or 1 m and 4 m, or 1 m and 3 m, and slightly wider than the entire width of the sheet of absorbent web-based material to be wrinkled. It first forms a counter-roll gap against the pressure rollers or multiple pressure rollers, then dries the sheet by conductive heat, and finally provides a platform on which wrinkling occurs. A wrinkling scraper (sometimes also called a stationary scraper) extending along the width of the Yankee drying cylinder at the wrinkling location can be used as a mechanical component for imparting wrinkling. The area where wrinkling occurs between the tip of the wrinkling scraper and the Yankee surface can be referred to as a wrinkling bag.

[0310] When manufacturing web-based absorbent materials, an alternative or additional process to the structural modification process is a rapid transfer applied as the web is moved from one surface to another (e.g., from a discharge permeable conveyor to a drying permeable conveyor). The structural change is caused by the velocity difference between the surfaces; this velocity difference causes compression and network deformation when the second surface moves at a lower velocity than the first surface, or network stretching when the second surface moves at a higher velocity than the first surface. Thus, the surface structure of the second surface can be fully or partially imprinted into the surface of the web-based absorbent material.

[0311] Transfer can be supported by applying a vacuum to ensure successful material transfer from the first surface to the second surface and / or to enhance structural modifications. Rapid transfer can be applied at any transfer point within the process when manufacturing web-based absorbent materials and can be applied across a wide range of solids contents.

[0312] The manufacturing of the final product may specifically include web processing.

[0313] The manufacture of the final product may include winding the absorbent web-based product.

[0314] The manufacture of the final product may include refining the manufactured absorbent web-based product, either alone or in combination with one or more further products. Refining may include any one or more of the following operations, which may be considered part of the tissue paper conversion process, such as folding, lamination, printing, coating, and embossing.

[0315] The manufacture of the final product may include transforming the manufactured absorbent web-based product into a packaged or unpackaged final product. A packaged final product may, for example, include or consist of a product already packaged in a plastic wrapping or other type of wrapping or packaging.

[0316] The final product can be a consumer final product, or it can be a retailer's or distributor's product. The final product can be multiple packages of a product. Furthermore, the final product can include, or consist of, packaged or unpackaged single-absorbent web-based product sheets or multi-sheet products, wherein a multi-sheet product includes at least one manufactured absorbent web-based product sheet. The final product can be a multi-sheet product comprising one or more manufactured absorbent web-based product sheets, wherein two or more sheets of the multi-sheet product can be identical or different from each other.

[0317] Single-layer or multi-layer final products can be rolled up, folded, stacked, bound, or grouped in another manner.

[0318] 3. Absorption based on web products This disclosure also relates to an absorbent web-based product manufactured by means of one or more aspects of the methods described above. One aspect may be one or more features, and in particular, a combination of the features discussed. Specifically, this disclosure also relates to an absorbent web-based product manufactured by means of one or more aspects of the methods described above.

[0319] The absorbency of web-based products that can be manufactured can reach 500 g / m². 2 Or smaller, or 300g / m 2 Or smaller, or 200g / m 2 Or smaller, or 150g / m 2 Or smaller, or 10 to 120 g / m 2 The base weight, and 5 to 200 kg / m 3 Or 8 to 150 kg / m 3 or 10 to 100 kg / m 3 or 10 to 70 kg / m 3 The density.

[0320] The change in basis weight σ, as measured according to SCAN-P 92:09, can be less than 20%, less than 15%, less than 10%, less than 5%, less than 3%, or less than 2% of the average basis weight of the absorbent web-based product. In particular, the change in basis weight σ can be determined by beta-formation analysis.

[0321] The principle of β-formation analysis is based on 14 The decay of C atoms, emitted electrons, antineutrinos, and the resulting nitrogen (N). In short, the test sample is placed in a radiation source ( 14 The electrons penetrating the test sample were measured on top of the C (active 1.18 GBq) using an imaging plate (BAS IP-MS2325). This is possible because the electron energy is continuous from 0 to the maximum decay energy Emax. The lower the electron measurement current, the more material between the radiation source and the imaging plate. The radiograph of the electrons in the imaging plate was read using a reader (BAS 1800 II4046) and converted into a basis weight map using Matlab. The result is a small-scale basis weight map of the sample. The pixel size is 1 mm * 1 mm. A suitable instrument for performing β-formation analysis is the Ambertec Bety Formation Tester (available from Ambertec Oy, Finland).

[0322] Based on the total weight of the absorbent web-based product, the absorbent web-based product may include at least 70% by weight of fiber material. The absorbent web-based product may have a density of 5 g / m². 2 or more, or 8g / m 2 or more, or 10g / m 2 or more and 500g / m 2 Or smaller, or 300g / m 2 Or smaller, or 200g / m 2 Or smaller, or 150g / m 2 Or smaller, or 10 to 120 g / m 2 The base weight and 5 to 200 kg / m 3 Or 8 to 150 kg / m 3 or 10 to 100 kg / m 3 or 10 to 70 kg / m 3 The density. In this context, the basis weight is determined by standard DIN / ISO 12625-6.

[0323] This can provide sufficient strength for the product, which in turn provides a sufficiently strong foundation for the end product for the user (such as hygiene products).

[0324] According to SCAN-P 92:09, the change in basis weight σ can be less than 20%, less than 15%, less than 10%, less than 5%, less than 3%, or less than 2% of the average basis weight of the absorbent web-based product.

[0325] More generally, absorbency-based products may include those with a thickness of 5 g / m². 2 or more, or 8g / m 2 or more, or 10g / m 2 or more and 500g / m 2 Or smaller, or 300g / m 2 Or smaller, or 200g / m 2 Or smaller, or 150g / m 2 Or smaller, or 120g / m 2 A single sheet with a basis weight of 5 g / m³ or less, or it may comprise more than one sheet (e.g., two, three, four, five, or six sheets), each sheet having a basis weight of 5 g / m³. 2 or more, or 8g / m 2 or more, or 10g / m 2 or more and 500g / m 2 Or smaller, or 300g / m 2 Or smaller, or 200g / m 2 Or smaller, or 150g / m 2 Or smaller, or 10 to 120 g / m 2 Optional 10 to 100 g / m 2 The base weight, and 5 to 200 kg / m 3 Or 8 to 150 kg / m 3 or 10 to 100 kg / m 3 or 10 to 70 kg / m 3 The density. (Monolayer) Absorbency: The density of web-based products can be specifically from 5 to 200 kg / m³. 3 Or 8 to 150 kg / m 3 or 10 to 100 kg / m 3 or 10 to 70 kg / m 3 Absorbency-based web products can be single-layer or multi-layer products, which can be customized according to the needs of the end user through further transformation steps.

[0326] Absorbent web-based products may have an upper side and a lower side, and the density of the absorbent web-based product located in the central region between the upper and lower sides in the thickness direction may be lower than the density of the absorbent web-based product located in the regions located on the lower side and / or upper side (multiple lower and / or upper sides).

[0327] Products based on absorbency may include surfactants. The presence of surfactants can allow verification that the product has been manufactured according to some embodiments of the methods disclosed herein.

[0328] Absorption properties based on web material can include one, two, or three of the following: (a) at least 0.2% by weight of one or more binders, (b) at least 0.05% by weight of one or more rheology modifiers, (c) at least 0.01% by weight of one or more surfactants, and (d) At least 0.2% by weight of one or more slip agents, The total weight of each product based on absorbency based on the web. The remainder may contain or be composed of fibers.

[0329] In one aspect, this disclosure also relates to a multi-layered product, such as a product comprising two, three, four, five, or six layers, comprising at least one layer made of an absorbent web-based product that can be manufactured according to one or more aspects of the methods described above. The multi-layered product may further comprise at least one nonwoven layer and / or at least one cotton paper layer, optionally conventional wet-pressed paper layers and / or structured layers and / or textured layers.

[0330] In another aspect, this disclosure relates to a multi-layered product, for example, comprising two, three, four, five, or six layers, which includes a product having 5 g / m³ of material. 2 or more, or 8g / m 2 or more, or 10g / m 2 or more and 500g / m 2 Or smaller, or 300g / m 2 Or smaller, or 200g / m 2 Or smaller, or 150g / m 2 Or smaller, or 10 to 120 g / m 2 The base weight and 5 to 200 kg / m 3 Or 8 to 150 kg / m 3 or 10 to 100 kg / m 3 or 10 to 70 kg / m 3 The density of the absorbency is based on at least one sheet made from the web material. The multi-layer product may further include at least one nonwoven sheet and / or at least one cotton paper sheet, optionally a conventional wet-pressed paper sheet and / or a structured sheet and / or a textured sheet.

[0331] The multi-layer product can be selected from the group consisting of: wipes, hygiene products (such as toilet paper), hand towels, household towels, towels, tissues for facial use (facial tissues), napkins / napkins, sheets and clothing.

[0332] 4. Equipment for manufacturing absorbent web-based products This disclosure also relates to an apparatus for manufacturing absorbent web-based products.

[0333] 4.1 Fibrous Foam Preparation Apparatus The equipment may include a fibrous foam preparation apparatus for preparing fibrous foam. The fibrous foam preparation apparatus may include a supply device for supplying (or configured to supply) fibers, one or more surfactants, a liquid, and a gas, wherein the fiber content is 5% to 60% by weight, the surfactant content is 0.02% to 1.20% by weight, the liquid content is 40% to 80% by weight, and the gas content is 64% or more by volume. The liquid may be water or may contain water. The gas may be air or may contain air.

[0334] The supply device can supply (or be configured to supply) a liquid comprising at least 80% water by weight and / or a gas comprising at least 95% air by volume.

[0335] A fibrous foam preparation apparatus may include a solids supply device for supplying solids, wherein the solids content may be 5% to 60% by weight, and wherein at least 80% by weight of the solids may be fibers. At least 85%, or at least 90%, or at least 95%, 97%, 98%, 99%, or 99.5% by weight of the solids may be fibers. All solids may be fibers.

[0336] The fibrous foam preparation apparatus can prepare (or can be configured to prepare) fibrous foam having a solid content, wherein the solid volume fraction can be 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less, and wherein at least 80% of the solid content can be fiber content.

[0337] The liquid may contain at least 80% water by weight. Alternatively, the liquid may contain at least 85%, 90%, 93%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.8%, or at least 99.9% water by weight. Using a large amount of water as the liquid can promote cost efficiency.

[0338] The fiber content can be from 5% to 60% by weight. The liquid content can be from 40% to 95% by weight. The gas content can be 64% or more by volume, and optionally at least 70%, at least 75%, or at least 80% by volume.

[0339] The gas may contain at least 95% air by volume. Alternatively, the gas may contain at least 96%, 97%, 98%, 99%, 99.5%, 99.8%, or at least 99.9% air by volume. Using a large amount of air as the gas can promote cost efficiency.

[0340] A fibrous foam preparation apparatus can be used to prepare (or configured to prepare) fibrous foam from fibers, liquids, and gases, wherein the fiber volume fraction is 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less. The liquid can be water or may contain water. The gas can be air or may contain air.

[0341] The device may include a liquid slurry preparation device that prepares (is configured to prepare) an intermediate mixture / slurry foam / slurry solution containing at least one component selected from the group consisting of liquids such as water, fibers, one or more surfactants, one or more binders, and one or more slip agents.

[0342] The device may include a surfactant supply device that supplies (or is configured to supply) at least one surfactant or a mixture of surfactants. The surfactant (among other surfactants) may be selected from anionic surfactants, cationic surfactants, amphoteric surfactants, amphoteric surfactants, and nonionic surfactants.

[0343] The fibrous foam preparation apparatus can transport (or be configured to transport) fibrous foam to the forming apparatus.

[0344] A fibrous foam preparation apparatus can facilitate (or be configured to facilitate) the preparation of fibrous foam and transport the fibrous foam to a foam layer forming apparatus via the same mechanical motion. This can particularly improve process efficiency and / or allow for a reduction in specific energy consumption.

[0345] The equipment may include a high-consistency mixing device. This high-consistency mixing device may be included in a transport device and may be part of the same structural unit as the transport device, processing device, and / or fibrous foam forming device.

[0346] 4.2 Fibrous Foam Forming Device The device may include a foam layer forming apparatus that forms (or is configured to form) fibrous foam into a foam layer.

[0347] A foam layer forming apparatus can (or be configured to) form fibrous foam in a planar form. The foam layer has two extension dimensions (two directions on the planar surface) and a thickness dimension, wherein the foam layer is thinner in the thickness dimension compared to the planar extension dimensions.

[0348] The formation of a foam layer may be beneficial in allowing for evaporation, particularly mechanical evaporation, but also in allowing for (thermal) drying. Furthermore, the foam layer can be considered a step towards a desirable form of absorbent web-based product, which is the base material for hygiene products such as tissue-like products.

[0349] A foam layer forming apparatus can make (or configure to make fibrous foam into) a planar layer. The planar form allows for efficient discharge (particularly for dehydration). Making fibrous foam into a planar layer can also be referred to as forming fibrous foam into a planar layer.

[0350] The apparatus may include a mold and / or a headbox and / or a cylindrical die, which can at least partially perform (or be configured to perform) the forming. The mold and / or headbox may include at least one foam forming section (flow section) on which fibrous foam flows to form a planar shape. In particular, the mold and / or headbox and / or cylindrical die may be formed such that the foam has a ratio of 8 or more between its length in the MD (machine direction) direction and its length in the CD (transverse machine direction). This ratio may be 2 or more, 4 or more, 6 or more, 9 or more, or 10 or more, or 11, or 12, or 13 or more.

[0351] The molding die and / or headbox may include two or more foam forming sections.

[0352] The die and / or headbox may include an outlet height of at least 0.5 mm, or at least 0.8 mm, 0.9 mm, or 1.0 mm. These minimum heights increase in degree to prevent or even avoid clogging. The outlet height may be a slit opening. The outlet height may be in the range of 0.5 mm to 5.0 mm, 0.8 mm to 4.0 mm, 0.9 mm to 3.0 mm, or 1.0 mm to 2.5 mm. The entrance height can be at least 1.5 times, 2.0 times, 3.0 times, 5.0 times, or 8.0 times the exit height.

[0353] The outlet height, or more generally, the opening size (e.g., the dimensions of the cross-section of the outlet surface), can be adapted to the desired foam consistency or product. The foam consistency, fiber volume fraction, and / or air content can be adapted to achieve the desired target basis weight of the foam layer. Additionally, the overall solids volume fraction, and particularly the fiber volume fraction, can also be customized according to the desired basis weight and / or density.

[0354] The molding die and / or headbox may include a lateral diffusion section shaped to promote lateral diffusion of the foam in order to increase the MD / CD size ratio of the foam.

[0355] 4.3 Discharge devices (e.g., dehydration devices) and drying devices The device may include a discharge device that discharges (or is configured to discharge) fibrous foam in a foam layer to form a fibrous web having a liquid content of 20% to 85% by weight.

[0356] A liquid content of 20% to 85% in fibrous webs can be considered a significantly low liquid content as a starting point for subsequent drying processes in the drying unit. This equipment can have lower specific energy consumption compared to equipment used in conventional sanitary papermaking processes. For example, the liquid content at the end of the discharge step can be half that encountered in comparable manufacturing methods prior to the drying step. This allows for the use of less energy compared to comparable manufacturing equipment that relies on conventional wet paper production.

[0357] Discharge devices can include mechanical discharge devices. Mechanical discharge relies on the use of mechanical force to remove liquids. When the liquid is water or contains water (or is substantially water), mechanical discharge can also be referred to as mechanical dehydration. Discharge devices can be dehydration devices. Mechanical discharge devices can be mechanical dehydration devices. Mechanical dehydration relies on the use of mechanical force to remove water.

[0358] Mechanical emissions can allow for a reduction in liquid content, and thus promote lower specific energy consumption in equipment, particularly with thermal drying (especially thermal dehydration). This can contribute to energy conservation and, consequently, environmental friendliness.

[0359] The discharge device may consist of a mechanical discharge device. It may include or consist of a mechanical dehydration device.

[0360] In this context, dehydration is understood to exclude drying; that is, in this context, dehydration is considered separate from heat emissions (especially thermal dehydration) in the sense of drying.

[0361] The venting device can apply (or be configured to apply) a vacuum to the foam layer at a constant or varying pressure. The variation can be temporal or spatial. In other words, the pressure can increase or decrease over time. Alternatively, the pressure can be higher or lower upstream and downstream (i.e., spatial pressure variation). The venting device can include or consist of one or more vacuum chambers.

[0362] The changing pressure can be a pressure that decreases at least once in the downstream direction of transport. The pressure can, for example, decrease and increase successively, decrease again, etc.

[0363] In some cases, the discharge may, in conjunction with control devices, apply (or be configured to apply) at least two stages of vacuum to the foam layer, optionally to reduce pressure. Between these stages, pressure may or may not be increased. In other words, several stages of pressure reduction and increase may exist.

[0364] The venting device can apply (or be configured to apply) a vacuum to the foam layer at a constant or varying pressure, wherein the varying pressure may optionally have at least one decrease in the downstream direction of transport. The venting device can apply (or be configured to apply) successive pressure decreases and / or increases, further decreases, etc.

[0365] The equipment may include a drying unit that dries (or is configured to dry) fibrous webs to obtain absorbent web-based products. The specific energy consumption associated with subsequent drying can be lower than that using conventional manufacturing processes. This, in turn, may be associated with the lower liquid content of the fibrous webs compared to known intermediate products. Furthermore, drying can reduce the liquid content to the level required for absorbent products.

[0366] Drying equipment may include or consist of thermal drying equipment. Drying equipment may include or consist of freeze drying equipment. Drying equipment may include or consist of infrared drying equipment. Drying equipment may include or consist of contact drying equipment. Drying equipment may include or consist of impact drying equipment. Drying equipment may include or consist of microwave drying equipment. Drying equipment may include or consist of ventilated drying (TAD) equipment. Drying equipment may include or consist of any combination of or consist of the types of drying equipment mentioned, including one or more specific types of drying equipment. In contrast to mechanical discharge devices, drying equipment can be specifically considered as thermal drying equipment.

[0367] The drying device can perform (or be configured to perform) drying, and the resulting absorbent web-based product can have a liquid content of 0.5% to 15% by weight. The liquid content can be 1% to 15% by weight. The liquid content can be 1% to 10% or 1.5% to 8% by weight. The liquid content can be 1.8% to 6.5% by weight. The liquid content can be 2% to 5% by weight. This increasingly narrow range of liquid content may be increasingly beneficial for achieving sufficient stability and consumer satisfaction with hygiene products, including absorbent web-based products.

[0368] Specifically, absorbency-based products can have a water content of 1% to 15% by weight. The water content can specifically be 1% to 10% by weight or 1.5% to 8% by weight. The water content can specifically be 1.8% to 6.5% by weight. The water content can specifically be 2% to 5% by weight.

[0369] 4.4 Processing Equipment The apparatus for preparing fibrous foam may include a processing apparatus for processing (or being configured to process) liquid slurry and / or foam and fibers into fibrous foam.

[0370] A fibrous foam preparation apparatus may include two or more processing units, wherein at least one of them can prepare liquid slurry and / or foam, and another of them can process (or be configured to process) liquid slurry and / or foam and fibers into fibrous foam.

[0371] A fibrous foam preparation apparatus may include two or more processing units, wherein at least one of them can process (or be configured to process) liquid slurry and fibers into fibrous foam, and another of them can process (or be configured to process) foam and fibers into fibrous foam.

[0372] The apparatus may further include one or more solid supply devices for supplying solids to the fibrous foam preparation apparatus, and one or more liquid supply devices for supplying liquids to the fibrous foam preparation apparatus, to form a fibrous foam having a solid content of 5% to 60% by weight, optionally more than 10% by weight, and a liquid content of 40% to 95% by weight, based on the weight of the fibrous foam. The one or more liquid supply devices may supply liquids at different stages of the preparation process, i.e., sequentially at different points in time or space during the preparation process.

[0373] Specifically, the solid supply device and the liquid supply device can be sized (and particularly relatively sized) to obtain fibrous foam with the desired (rheological) properties. Alternatively, the device may include one or more control devices configured to control the solid supply device and the liquid supply device to obtain fibrous foam with the desired (rheological) properties. Additionally, the one or more control devices may be configured to control the gas supply device, such as, for example, an air supply device.

[0374] A fibrous foam preparation apparatus may include a rheology modifier supply device for supplying (or being configured to supply) a rheology modifier. The rheology modifier (of various types) may be particularly useful for defiberizing fibrous materials and / or achieving desired rheological properties for formation.

[0375] A fibrous foam preparation apparatus can prepare (or can be configured to prepare) fibrous foam having a solids content of more than 10% by weight. The solids content may specifically refer to the fiber content, and the fiber content may be more than 10% by weight (of the fibrous foam).

[0376] The device may include at least one rotatable device, and the device may (or be configured to) contact one or more of liquid slurry, foam, solid, liquid and fibrous foam with the at least one rotatable device and rotate (or be configured to rotate) the at least one rotatable device to transport fibrous foam.

[0377] The rotation of at least one rotatable device can also process fibrous foam or facilitate the processing of fibrous foam. The same mechanical motion can be used particularly effectively because transport, as well as processing and / or forming, can all be facilitated by the same motion.

[0378] The device can cause (or be configured to cause) the at least one rotatable device to rotate at 100 to 5000 rpm, or 500 to 3000 rpm, or 800 to 2800 rpm, or 1000 to 2500 rpm, or 1600 to 2400 rpm.

[0379] The rotatable device may include a high-shear mixer, and the mixer may operate at a speed of 100 rpm or more. The speed may be 200 rpm or more and 5000 rpm or less, or 200 rpm or more and 2000 rpm or less, or 200 rpm or more and 1000 rpm or less, or 200 rpm or more and 600 rpm or less.

[0380] The rotation of the at least one screw can facilitate at least one of the following: transport, mixing, defiberization, applying pressure to fibrous foam, and establishing pressure on fibrous foam.

[0381] The equipment may include at least one processing device selected from the following list: industrial mixer, screw kneader, industrial kneading machine, extruder, single-screw or twin-screw machine, single-screw or twin-screw continuous kneader, twin-screw or multi-screw machine, conical screw mixer, wherein the at least one processing device includes the at least one rotatable device.

[0382] The device may include a screw mixer. The screw mixer may be, for example, a conical screw mixer. The screw mixer may, in particular, be transported by the conveying device described above. The screw mixer may, for example, include at least a rotating device (in this case, the screw).

[0383] The device may include a fully automatic foam generator capable of producing foam, for example, with a density between 50 and 1000 g / L. It may include a temperature-controlled mixing head and may include a double-acting mechanical seal. It may further be controlled by automatic air volume control and, for example, by a touchscreen or PLC. The screw mixer may include, for example, an eccentric screw pump (e.g., gasket-free), or, for example, a temperature-controlled storage tank.

[0384] The device may include a supply device that supplies (or is configured to supply) at least one component selected from the following list as the fibrous foam is transported through the processing device: - A liquid, such as water, which may optionally contain one or more additives; - Gases, such as air; - Foam and / or liquid slurries; and - Solids, such as fibers, powders and / or granules.

[0385] The at least one rotating device can be a twin screw, a single screw, or a multi-screw.

[0386] The at least one rotating device may include one or more of the following sections: an acceleration section that accelerates (or is configured to accelerate) fibrous foam being transported through a transport device (such as, for example, an extruder, mixer, or kneader); a deceleration section that decelerates (or is configured to decelerate) fibrous foam being transported through a transport device; and a shear and / or elongation application section that applies (or is configured to apply) shear and / or elongation forces to the fibrous foam.

[0387] The device may include a screw assembly, which includes a housing and at least one rotatable device.

[0388] The closest distance between the at least one rotating device and the relative inner surface of the housing can be in the range of 0.3mm to 20mm, or 0.4mm to 15mm, or 0.45mm to 12mm, or 0.5mm to 10mm, or 0.7mm to 7mm, or 0.8mm to 5mm, or 0.9mm to 3mm, or 0.93mm to 2mm, or 0.95mm to 1.5mm.

[0389] The device may include a displacement pump. The displacement pump may be, for example, a rotary cam pump, a progressive chamber pump, a rotary gear pump, a piston pump, a diaphragm pump, a screw pump, a gear pump, a hydraulic pump, a rotary vane pump, a peristaltic pump, a rope pump, a flexible impeller pump, and the like, which displaces (or is configured to displace) fibrous foam prior to its formation. The displacement pump may be included in the transport device described above.

[0390] The processing apparatus can be located in a controlled pressure chamber. The foam layer forming apparatus can be located in a controlled pressure chamber. The processing apparatus and the foam layer forming apparatus can be located in the same controlled pressure chamber or in different controlled pressure chambers.

[0391] 4.5 Transport Equipment The equipment may include a transport device that transports (or is configured to transport) liquid slurry and / or foam and / or fibrous foam and / or solids such as fibers to a foam layer forming device.

[0392] The processing apparatus may include a transport device, and the transport device may perform at least a portion of the processing.

[0393] The transport device can perform processing. The processing device and the transport device can be a single, identical structural unit.

[0394] Unitized transport and processing, or more generally, transport and foam formation, can at least partially or even entirely improve the space efficiency of the machines required for manufacturing processes. Furthermore, unitizing different steps and performing them within a single, multi-purpose device can improve processing speed (since one identical step can facilitate more than one processing step simultaneously) and can contribute to reducing specific energy consumption.

[0395] One or more of the following components may be part of a single integral structural unit: processing device, fibrous foam preparation device, conveying device, forming device, heating device, and discharge device. For example, two of the listed components may be a single unit, i.e., a structurally integral unit. Alternatively, any three or all four of the listed components may be a single unit, i.e., a structurally integral unit. This allows for a particularly space-saving construction of the equipment. Alternatively or additionally, it may allow for the simultaneous utilization of different functions of the same device, which can promote the production efficiency and / or energy efficiency of the equipment.

[0396] The transport device may include a pressurization section that increases (or is configured to increase) the pressure applied to the liquid slurry or fibrous foam during transport in the downstream transport direction. The increase in pressure can be achieved by changing the transport speed (e.g., by subsequently increasing and decreasing the transport speed, or vice versa). More generally, the pressurization section may increase (or be configured to increase) the pressure applied to the liquid slurry or fibrous foam during transport at least twice and / or decrease (or be configured to decrease) the pressure applied to the liquid slurry or fibrous foam during transport at least twice.

[0397] Pressure can be increased or decreased by, for example, by at least 0.1 bar. Pressure can be increased several times. Pressure can be decreased once or several times. Pressure can be increased and decreased several times.

[0398] Increasing and / or decreasing pressure can help alter the properties of the processed foam. In particular, fibrous foams can include both compressible and incompressible compounds. Thus, changes in pressure can alter the fiber volume fraction of the fibrous foam and therefore affect its rheological properties.

[0399] The pressurized section can apply multiple different pressure levels in succession (or be configured to apply them in succession) in the downstream direction, with the pressure level increasing at least twice.

[0400] The processing (or transport) apparatus may perform (or be configured to perform) at least one of the following: applying shear force, mixing, defibrinating, antiflocculation, refining, dispersing, disintegrating, altering fiber shape, heating the slurry to improve subsequent discharge, and adding chemical additives. Any one or more of the types of processing listed may be used to modulate and control the properties of fibrous foams, such as viscosity and / or rheology.

[0401] Fibrous foams can be prepared to exhibit properties according to the following curve method at 0.01 s. -1Viscosity measured at shear rates in the range of 50 to 2000 Pa·s (as described in Section 2.f below), and storage modulus in the linear viscoelastic region in the range of 400 to 2500 Pa (as described in Section 2.f below).

[0402] The fibrous foam can then be formed into a foam layer, which has a curvature of 0.01 s according to the curve method below. -1 Viscosity measured at shear rates in the range of 50 to 3000 Pa·s (as described in Section 2.f below), and storage modulus in the linear viscoelastic region in the range of 500 to 10000 Pa (as described in Section 2.f below).

[0403] This processing can be specifically used to reduce the fiber volume fraction. Alternatively, processing can be performed to keep the fiber volume fraction more or less the same. Alternatively, processing can be performed to increase the fiber volume fraction.

[0404] 4.6 Control Device The device may include a temperature control device that controls (or is configured to control) the temperature inside at least one section of the device.

[0405] The device may include a control device that controls (or is configured to control) the device to perform any one or more of the methods described above.

[0406] 4.7 Manufacturing equipment for the final product This disclosure also relates to an apparatus for manufacturing a final product. The apparatus for manufacturing a final product may include equipment for manufacturing absorbent web-based products according to any one or more of the aspects discussed above. The apparatus for manufacturing a final product may include any one or more of the following components: web processing devices, winding devices, refining devices, and conversion devices for converting into packaged or unpackaged final products. Attached Figure Description

[0407] The following description is given with reference to the accompanying drawings, in which: Figure 1A This is a schematic diagram of an apparatus for manufacturing absorbent web-based products according to embodiments of the present disclosure; Figure 1B This is a schematic diagram of an embodiment of an apparatus for manufacturing absorbent web-based products according to embodiments of the present disclosure; Figure 2 An exemplary apparatus for preparing fibrous foam is described; Figure 3A A perspective view depicting a portion of an exemplary foam layer forming apparatus; Figure 3B Depicting Figure 3A A portion of an exemplary foam layer forming apparatus, without an upper cover, such that a portion of the inner side is visible; Figure 3C A cross-sectional side view of a compression mold, which serves as an example of a foam layer forming apparatus; Figure 4A A cross-sectional view of a twin-screw pump, which is an example of a transport device for manufacturing web-based absorbent products according to this disclosure. Figure 4B A cross-sectional view of a cam pump, which is an example of a transport device for manufacturing web-based absorbent products according to this disclosure. Figure 5A This is a perspective view of an extruder, which serves as an example of a transport device for manufacturing web-based absorbent products according to this disclosure. Figure 5B Depicting Figure 5A The extruder, but part of the housing was removed to expose the interior; Figure 6A Depicts a portion of the twin-screw extruder; Figure 6B Depicts a portion of the twin-screw extruder exposed from its casing; Figure 6C Show Figure 6A and Figure 6B A cross-sectional view of the twin screw and its housing together; Figure 7A Depicting a portion of another embodiment of an extruder, the extruder including a plurality of screws positioned inside its common housing; Figure 7B As depicted as a part of an embodiment of an extruder, the extruder includes a plurality of screws positioned inside its common housing 31; Figure 8 Depicts an emission device of an apparatus for manufacturing web-based absorbent products, according to the present disclosure, used when performing an embodiment of the method according to the present disclosure; Figure 9 A drying apparatus according to the present disclosure for manufacturing web-based absorbent products is described for use when performing embodiments of the method according to the present disclosure; Figure 10A Depicts a web processing device of an apparatus for manufacturing web-based absorbent products, according to the present disclosure, used when performing embodiments of the methods according to the present disclosure; Figure 10B An alternative web processing device is described, which involves a stage of wrinkling a web-based absorbent product. Figure 11This is a block diagram illustrating features of an embodiment of a method for manufacturing a web-based absorbent product according to the present disclosure; Figure 12 It is a graph showing the relationship between the fiber content and the air content of fibrous foam; Figure 13 It is a graph showing the relationship between the solid content and the air content of fibrous foam; Figure 14 This is a graph showing the correlation between the fiber volume fraction of fibrous foam and the storage modulus G′ of fibrous foam. Figure 15 This is a photograph of a stress-controlled TA Instruments DHR-2 rheometer equipped with a blade geometry in a cup for measuring the rheological properties of fibrous foam samples manufactured according to this disclosure; Figure 16 A cross-section is depicted through a sheet of an embodiment of an absorbent web-based product according to this disclosure; Figure 17 A cross-section through a multilayer product is depicted, including embodiments of absorbency-based web products according to this disclosure; Figure 18 A cross-section is depicted through a multilayer product comprising two layers of an absorbency-based web product according to this disclosure; Figure 19 A cross-section is depicted through a multi-layered product comprising sheets formed of foam according to embodiments of absorbent web-based products according to this disclosure; Figure 20 A cross-section is depicted through a multi-layered product comprising sheets formed of foam according to embodiments of absorbent web-based products according to this disclosure; Figure 21 A cross-section is depicted through a multi-layered product comprising sheets formed of foam according to embodiments of absorbent web-based products of the present disclosure; Figure 22 A cross-section is depicted through a multi-layered product comprising sheets formed of foam according to embodiments of absorbent web-based products of the present disclosure; Figure 23 A cross-section is depicted through a multi-layered product comprising sheets formed of foam according to embodiments of absorbent web-based products of the present disclosure; Figure 24 A cross-section is depicted through a multi-layered product comprising sheets formed of foam according to embodiments of absorbent web-based products of the present disclosure; Figure 25A Micro-CT measurement images of the top side of a structured sheet (TAD sheet) manufactured according to a conventional TAD manufacturing process; Figure 25B A micro-CT measurement image of the top side of a sheet of foam manufactured according to the present disclosure is shown; Figure 26A Micro-CT measurement images depicting the underside of a structured sheet (TAD sheet) manufactured according to a conventional TAD manufacturing process; Figure 26B A micro-CT measurement image of the underside of a sheet of foam manufactured according to the present disclosure is shown; Figure 27A Micro-CT measurement images of the top side of a structured sheet (TAD sheet) manufactured according to a conventional TAD manufacturing process; Figure 27B A micro-CT measurement image of the top side of a sheet of foam manufactured according to the present disclosure is shown; Figure 28A Micro-CT measurement images depicting the underside of a structured sheet (TAD sheet) manufactured according to a conventional TAD manufacturing process; Figure 28B A micro-CT measurement image of the underside of a sheet of foam manufactured according to the present disclosure is shown; Figure 29A Micro-CT measurement images depicting cross-sections taken through structured sheets (TAD sheets) manufactured according to conventional TAD manufacturing processes; and Figure 29B Micro-CT measurement images showing a cross-section taken through a sheet formed from foam manufactured according to this disclosure. Detailed Implementation

[0408] Figure 1A A schematic diagram depicts an apparatus 10 for manufacturing absorbent web-based products according to embodiments of the present disclosure. Methods according to embodiments of the present disclosure can be performed on this apparatus 10.

[0409] Figure 1A The equipment 10 includes a fibrous foam preparation apparatus 20 for preparing fibrous foam. Figure 1A The fibrous foam preparation apparatus 20 is a mixer. However, the mixer is merely an example, and other embodiments may include different fibrous foam preparation apparatuses. A fibrous foam preparation apparatus may include or consist of one or more devices.

[0410] The arrow pointing laterally towards the fibrous foam preparation apparatus 20 indicates the supply device 25, which can supply the fibrous foam preparation apparatus 20 with at least fibers, one or more surfactants, liquids, and gases.

[0411] The supply device 25 includes a solids supply device (indicated by one of the side arrows) for supplying solids. For example, the solids supply device may supply a solids content of 5% to 60% by weight, wherein at least 80% by weight of the solids is fiber.

[0412] The supply device 25 also includes one or more liquid supply devices (indicated by one or more lateral arrows) for supplying liquid to the fibrous foam preparation device 20 to form fibrous foam. The fibrous foam may, for example, be formed having a solid content of 5% to 60% by weight of the fibrous foam, optionally greater than 10% by weight of the fibrous foam, and a liquid content of 40% to 95% by weight of the fibrous foam.

[0413] The supplied solids are dispersed in a solid-liquid dispersion to be prepared into a fibrous foam.

[0414] The supply device 25 may include a rheology modifier supply device for supplying rheology modifiers.

[0415] pass Figure 1A The fibrous foam prepared by the apparatus described herein may have a fiber content of 5% to 60% by weight, a surfactant content of 0.02% to 1.20% by weight, a liquid content of 40% to 95% by weight, and a gas content of 64% or more by volume. The above defines a narrower range that can be used in the various embodiments.

[0416] The supply device 25 can supply liquids, surfactants, fibers and gases (and optionally, other chemical components) dispersed in the liquid, containing at least 80% water by weight, and / or gases dispersed in liquids and / or foams containing at least 95% air by volume.

[0417] The fibrous foam can, for example, be prepared to have a fiber volume fraction of 0.040 or less. Alternatively, as described above, a narrower range of fiber volume fractions is associated with each embodiment.

[0418] More generally, fibrous foams can be prepared to have a solids content of 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less, and wherein at least 80% of the solids content is fiber content.

[0419] The fibrous foam preparation apparatus 20 can prepare a gas-liquid dispersion containing at least 80% by weight of water and / or at least 95% by volume of air.

[0420] Figure 1A The device 10 includes a transport device 30, which includes sections constituting a foam layer forming device 33, which forms a foam layer from fibrous foam (prepared by the fibrous foam preparation device 20). The device 10 supplies the fibrous foam prepared by the fibrous foam preparation device 20 to the transport device 30. This... Figure 1A The arrow pointing from the fibrous foam forming device 20 to the transport device 30 indicates this. The transport device 30 transports the fibrous foam and forms it into a foam layer in the section constituting the foam layer forming device 33.

[0421] Figure 1A The transport device 20 includes a pressurization section that increases the pressure applied to the liquid slurry or fibrous foam during transport in the downstream direction (from left to right in the figure).

[0422] The resulting foam layer is then transferred to the permeable conveyor 40 and conveyed together with it.

[0423] Figure 1A The device 10 further includes a discharge device 50 that discharges fibrous foam from the foam layer to form a fibrous web with a liquid content of 20% to 85% by weight.

[0424] also, Figure 1A The device 10 includes a drying unit 60 that dries fibrous webs to form absorbent web-based products.

[0425] Figure 1A The equipment 10 also includes a web processing device 70, which includes a winding device 72. The web processing device 70 removes the manufactured web-based absorbent product from the conveyor section 71 and feeds it into the winding device 72.

[0426] Figure 1B An embodiment of an apparatus 10 for manufacturing absorbent web-based products is schematically depicted. Figure 1A and Figure 1B The parts are similar, and similar parts are indicated by the same reference numerals. Descriptions of similar parts will not be repeated, but will be referred to in the accompanying drawings. Figure 1A The description.

[0427] Figure 1A and Figure 1B The difference between them is that, Figure 1B The fibrous foam forming apparatus / processing apparatus / transporting device 20A of the embodiment is depicted more specifically, that is, as a transport device including a rotatable device rotatable by a motor 35. Figure 1BThe device 10 brings liquid slurry and / or foam and / or fibrous foam transported by the transport device into contact with the rotatable device. More generally, as in... Figure 1A As described in the context, liquids, fibers (e.g., dried fibers) and chemical components (such as surface additives) are supplied to the fibrous foam forming apparatus 20A, gases are supplied, and solids are dispersed to prepare a gas-liquid dispersion for preparing fibrous foam.

[0428] The rotatable device is rotated by a motor 35 to transport fibrous foam. Depending on the embodiment, the rotational speed of the rotatable device is set in the range of 100 to 5000 rpm.

[0429] The rotatable device, through the rotation of motor 35, can facilitate the formation, processing, and transportation of fibrous foam through the same mechanical motion.

[0430] The rotatable device can facilitate one or more of the following by rotating the motor 35: transport, mixing, defibrination, applying pressure to fibrous foam, and building pressure on fibrous foam.

[0431] Figure 1A Foam forming apparatus / processing apparatus / transport apparatus 20 or Figure 1B The foam forming apparatus / processing apparatus / transport apparatus 20A may each be any of the following: industrial mixer, screw kneader, industrial kneading machine, extruder, single-screw or twin-screw machine, single-screw or twin-screw continuous kneader, twin-screw or multi-screw machine, conical screw mixer, which includes at least one rotatable device.

[0432] Figure 1B The foam forming apparatus / processing apparatus / transport apparatus 20A includes a housing that accommodates a rotatable device. The minimum distance between the rotatable device and the relative inner surfaces of the housing (i.e., the minimum distance achieved when considering all positions, especially all rotational positions of the rotatable device) is in the range of 0.3 mm to 20 mm.

[0433] The transport device 30A includes a section constituting a foam layer forming device 33A, which forms a foam layer from fibrous foam. Then, similar to... Figure 1A As described in the context, a foam layer is supplied to a permeable conveyor 40. The permeable conveyor 40 conveys the foam layer through a discharge device 50 and a drying device 50.

[0434] Figure 2 An exemplary foam preparation apparatus 20, namely a mixer 20B, is described in more detail. The mixer 20B can be used to prepare foam, and in this case, it is used to prepare fibrous foam.

[0435] Mixer 20B is an example of a processing apparatus for processing liquid slurry or foam and fibers into fibrous foam. Mixer 20B can be used to partially prepare fibrous foam, which can then be further processed as follows: Figure 1A In the fibrous foam forming apparatus 20 shown or as... Figure 1B The preparation continues in the fibrous foam forming apparatus 20A shown. In other words, in some embodiments, a portion of the fibrous foam formation may have already been processed using, for example... Figure 1A and Figure 1B The fibrous foam forming apparatus / processing apparatus / transportation apparatus of the illustrated embodiment occurs before processing. In other embodiments, the entire fibrous foam forming occurs within the overall fibrous foam forming apparatus / processing apparatus / transportation apparatus (e.g., as shown in the illustration). Figure 1A and 1B (As shown).

[0436] The mixer 20B includes a rotor 21 that can be used to mix the supplied components and thereby apply shear force to defiberize, prevent flocculation, refine, disperse, disintegrate, change the shape of fibers, and heat the slurry and / or foam (towards the fibrous foam at the end of the process), as well as heat the slurry or foam while adding chemical additives thereto.

[0437] Mixer 20B includes an input 23 for feeding chemicals and / or fibers, and an air input including a compressor 22 for compressing the air to be supplied to the mixing chamber. After the mixing process, mixer 20B outputs fibrous foam to transport pump 24, which, depending on the embodiment, may be the transport device itself, or may pump the fibrous foam toward transport device 30.

[0438] Figure 3A A perspective view depicting a portion of an exemplary foam layer forming apparatus 33 / 33A. This exemplary foam layer forming apparatus 33 / 33A is a compression mold 33B.

[0439] The mold 33B includes an inlet 41 and an outlet 42. Fibrous foam is fed into the mold 33B through the inlet 41. The mold 33B forms the fibrous foam into a foam layer. The mold 33B includes an outlet 42 through which the foam layer exits the mold 33B.

[0440] Figure 3A The mold 40A is depicted from the outside. The mold 33B includes a housing with an upper cover 43 and a lower cover 44, which are embedded together in a hollow space having a shape designed to form fibrous foam, which is transported in a downstream direction into a planar shape, i.e., forming a foam layer.

[0441] Figure 3B Depicting Figure 3AThe mold 33B has no upper cover 43, making a portion of the inner side (hollow space) of the mold 33B visible.

[0442] The space within the mold includes a high but narrow portion 45 near the inlet 41 and a shallow but wide portion 46 near the outlet 42, where the fibrous foam begins to widen and flatten. In fact, in the depicted embodiment, there is a continuous transition in the geometry of the hollow space, which promotes the fibrous foam to form an increasingly flattened shape towards the downstream side of the foam flow.

[0443] Figure 3C Depicting Figure 3A and Figure 3B A cross-sectional side view of the compression mold 33B. Figure 3C In the view, it is easy to see that the height of the interior space (the hollow space in which the fibrous foam is formed) is in the downstream direction ( Figure 3C It gets narrower and narrower from left to right.

[0444] Figure 4A A cross-sectional view of a twin-screw pump 30B (which may also be a processing device and / or a foam layer forming device) is depicted as an example of a transport device for manufacturing web-based absorbent products according to the present disclosure, used in performing embodiments of the method according to the present disclosure.

[0445] The twin-screw pump 30B includes a pump body 34 with an inlet 39 and an outlet 36. The pump body 34 houses a first screw 37A and a second screw 37B that together form a twin screw, as well as corresponding shafts 38A and 38B.

[0446] Figure 4B A cross-sectional view of a cam pump 30C (which may also be a processing device and / or a foam layer forming device) is depicted as an example of a positive displacement pump for a conveying device of an apparatus for manufacturing a web-based absorbent product according to the present disclosure, used when performing an embodiment of the method according to the present disclosure.

[0447] The cam pump 30C includes a housing 38 with an inlet 36A and an outlet 39A, and two cams 37C and 37D housed therein for displacing fibrous foam.

[0448] Figure 5A This is a perspective view of an extruder 30D (which may also be a processing device and / or a foam layer forming device) as an example of a transport device for manufacturing web-based absorbent products according to the present disclosure, used when performing embodiments of the method according to the present disclosure.

[0449] Before reaching the extruder 30D, fibrous foam is prepared, and then the extruder 30D transports the fibrous foam in the downstream direction by rotating the extruder screw 32, which is positioned inside the extruder housing 31.

[0450] Figure 5B Extruder 30D is shown, but part of the housing has been removed to expose the interior. (As shown in...) Figure 5B As can be seen, the extruder 30D includes the extruder screw 32.

[0451] Although Figure 5A and Figure 5B The extruder 30D includes a single extruder screw 32, but other embodiments may include two or more screws. Figure 6A A portion of the twin screws 32A (two extruder screws operating together) is shown within their common housing 31A.

[0452] In the illustrated embodiment, the closest approach distance between the two screws of the twin-screw 32A is approximately 1.25 mm. However, in other embodiments, the closest approach distance may be different and may be located elsewhere, for example, within the range of 0.3 mm to 20 mm.

[0453] Figure 6B A portion of the twin-screw 32A under discussion is shown without the housing 31A.

[0454] Figure 6C Show Figure 6A and Figure 6B A cross-sectional view of the twin screw 32A and its housing 31A together.

[0455] Figure 7A This depicts a portion of another embodiment of an extruder, which includes a plurality of screws 32B positioned inside a common housing 31B. The housing 31B has a cylindrical shape, but this is merely an example, as the shape of the housing may vary significantly from embodiment to embodiment. Figure 7A In the embodiment, multiple screws 32B are arranged circumferentially around the central bearing unit 45.

[0456] Figure 7B A portion of an embodiment of an extruder is also depicted, the extruder including a plurality of screws 32C positioned inside a common housing 31C. The housing 31C has a planar cuboid shape, as another example of a possible housing shape. In this embodiment, the plurality of screws 32C are arranged adjacent to each other in a planar configuration.

[0457] Figure 8 Depicts an emission device 50 of an apparatus for manufacturing web-based absorbent products according to the present disclosure, used when performing an embodiment of the method according to the present disclosure.

[0458] Before reaching the emission device 50, the fibrous foam has already formed into a foam layer L. The foam layer L extends downstream ( Figure 8 The transport is carried out from left to right (as indicated by the arrow pointing to the right).

[0459] The discharge device 50 includes a vacuum station 51 that applies a vacuum to the foam layer L and removes liquid in such a way that (in particular, in the case of the illustrated embodiment, defluidization: dehydration) to form a fibrous web with a liquid content of 20% to 85% by weight.

[0460] The discharge device 50 includes a vacuum pump 52 for generating a vacuum to dehydrate the foam layer L.

[0461] Figure 9 A drying apparatus 60 for manufacturing web-based absorbent products is depicted for use when performing embodiments of the methods according to the present disclosure.

[0462] A fibrous web W is formed prior to the drying step via the drying apparatus 60. It is then conveyed toward the drying apparatus 60 to perform thermal drying, further defluidizing (particularly dehydrating) the fibrous web W to form an absorbent web-based product according to this disclosure.

[0463] Figure 10A Depicts a web processing device 70 of an apparatus for manufacturing web-based absorbent products according to the present disclosure, used when performing an embodiment of the method according to the present disclosure.

[0464] Web processing device 70 includes winding device 72. Web processing device 70 removes manufactured web absorbent product from conveyor section 71 and feeds it into winding device 72.

[0465] Figure 10B An alternative web processing device 70A is described, which involves a stage for creping absorbent products based on webs. Specifically, the web processing device 70A includes a creping blade 73 (also referred to as a fixed scraper) and a Yankee drying cylinder 74. The area between the tip of the creping blade 73 and the surface of the Yankee surface is referred to as the creping pocket where creping occurs.

[0466] The speed difference between the Yankee drying cylinder (where the unwrinkled web-based absorbent product is fed) and the roll (where the web-based absorbent product is wrinkled after wrinkling) defines the wrinkling ratio. The web-based absorbent product is supplied from the roll to the conversion process to manufacture the finished product.

[0467] Figure 11 This is a block diagram illustrating features of an embodiment of a method for manufacturing a web-based absorbent product according to the present disclosure. Specifically, Figure 11The features of a method for controlling an apparatus used to manufacture web-based absorbent products are shown.

[0468] To prepare fibrous foam, the necessary materials are supplied. This is represented by supply steps S0a and S0b, where step S0a involves, for example, the supply of water such that the water content is 40% to 95% by weight, the supply of fibers such that the fiber content is 5% to 60% by weight, and the supply of surfactant such that the surfactant content is 0.02% to 1.20% by weight, and step S0b involves the supply of air. Of course, there may be a large number of distinguishable supply steps. Steps S0a and S0b are intended to represent only the supply.

[0469] In step S1, a fibrous foam is prepared, wherein the preparation includes dispersing supplied fibers and one or more supplied surfactants in a supplied liquid, and dispersing gas in the liquid until a desired gas content (64% or more by volume) is achieved. For different embodiments, the desired gas content is set differently (it may be set, for example, 70%, 75%, 80%, 85%, 90%, or 95%, etc.).

[0470] In step S2, the air content is measured periodically (continuously in some cases, intermittently in others, etc.), and the measured values ​​are fed back to the control unit (step S3). The control unit controls the preparation process, including, in particular, mixing. The feedback loop also allows the control unit to modify the amount supplied in supply steps S0a and S0b.

[0471] When the air content measurement in step S2 indicates that the fibrous foam has the desired consistency, the fibrous foam is supplied to the transport device in step S4.

[0472] Figure 12 This is a graph showing the relationship between the fiber content (by weight%) and air content (by volume%) of fibrous foam. Specifically, Figure 12 The line shows a constant fiber volume fraction. That is, by adjusting the corresponding air content, the same fiber volume fraction can be achieved with different fiber contents, and vice versa.

[0473] Figure 13 A similar graph is used, this time showing the relationship between the solids content (by weight%) and air content (by volume%) of the fibrous foam. That is, the solids volume fraction is based on all solids contained in the fibrous foam. For some embodiments, the solids volume fraction may be essentially the fiber volume fraction, but for other embodiments, 99%, 98%, 97%, or less (e.g., 90%) of the solids may be fibers. In other words, the solids volume fraction can be considered more general in this respect. Similar to... Figure 12 , Figure 13 The line shows a constant solids volume fraction. That is, by adjusting the corresponding air content, the same solids volume fraction can be achieved with different solids contents, and vice versa.

[0474] Figure 14 The graph illustrates the correlation between the fiber volume fraction (x-axis) of the fibrous foam and the storage modulus G′[Pa] (y-axis) measured at a strain amplitude of 0.025% and an angular frequency of 10 rad / s.

[0475] Storage modulus G′ [Pa] represents the elastic component of material stiffness. Storage modulus G′ [Pa] can be considered as the energy elastically stored in the material when it deforms and can then be reversibly released.

[0476] Storage modulus G′ [Pa] is one of the two components that make up complex modulus G* (or complex modulus), which is a measure of a material's resistance to deformation, i.e., the total stiffness of a viscoelastic material. The other component is loss modulus, which represents the energy dissipated as heat when a material undergoes deformation.

[0477] The "storage modulus" or "elastic modulus" G′ is defined as: G′ = G*cos(δ) The "loss modulus" or "viscous modulus" G′′ is defined as: G′′ = G*sin(δ) Where tanδ = G′′ / G′ is a measure of the material’s elasticity (tanδ<1) or viscosity (tanδ>1).

[0478] Figure 15 This is a photograph of a stress-controlled TA Instruments DHR-2 rheometer equipped with a blade geometry in a cup for measuring the rheological properties of fibrous foam samples manufactured according to this disclosure (and using equipment according to this disclosure).

[0479] Figure 16 A cross-section is depicted through a sheet of an embodiment of an absorbent web-based product 100 according to the present disclosure.

[0480] Figure 16 Product 100 is a monolayer product manufactured using the foam forming technology described herein. Based on its total weight, it contains over 70% by weight of fiber material. Furthermore, it has a density of 5 g / m³. 2 or more, or 8g / m 2 or more, or 10g / m 2 or more and 500g / m 2 Or smaller, or 300g / m2 Or smaller, or 200g / m 2 Or smaller, or 150g / m 2 Or smaller, or 10 to 120 g / m 2 The base weight, and 5 to 200 kg / m 3 Or 8 to 150 kg / m 3 or 10 to 100 kg / m 3 or 10 to 70 kg / m 3 The density.

[0481] Figure 16 Product 100 may contain at least 0.2% by weight of one or more binders based on absorbency based on the web material.

[0482] Figure 16 Product 100 may contain at least 0.05% by weight of one or more rheology modifiers based on absorbency based on the web material.

[0483] Figure 16 Product 100 may contain at least 0.01% by weight of one or more surfactants based on absorbency based on the web material.

[0484] Figure 16 Product 100 may contain at least 0.2% by weight of one or more slip agents based on absorbency based on the web material.

[0485] Product 100 is manufactured based on embodiments of the structural components and method steps described with reference to the foregoing figures.

[0486] Figure 17 A cross-section through a multilayer product 110 is depicted, the multilayer product 110 including embodiments of absorbent web-based products 111 according to the present disclosure. Figure 17 Product 110 is a double-layer product.

[0487] The absorbency of multi-layer product 110 is based on web-based product 111 and Figure 16 The products depicted are identical to those in the previous text, and their descriptions will not be repeated.

[0488] The multi-layer product 110 includes another layer 112. This additional layer 112 can be a nonwoven layer or a paper layer, such as a conventional wet-pressed paper layer, a structured layer (e.g., TAD, ATMOS, etc.), or a textured layer.

[0489] Figure 18 A cross-section is depicted through a multi-layer product 120, which includes two layers 121 and 123 according to embodiments of absorbent web-based products according to the present disclosure. Figure 18 Product 120 is a three-layer product.

[0490] Multi-layer product 120 with absorbent web-based product layers 121 and 123 and Figure 16 The sheets constituting product 100 depicted herein are identical and will not be described again. Sheets 121 and 123 may be the same or they may be different.

[0491] The multi-layer product 120 includes another layer 122. This additional layer 122 can be a nonwoven layer or a paper layer, such as a conventional wet-pressed paper layer, a structured layer (e.g., TAD, ATMOS, etc.), or a textured layer.

[0492] Alternatively, a foam-formed sheet may be combined with two or more further sheets, or a selected number of other foam-formed sheets may be combined with a selected number of further sheets, each of which is a nonwoven sheet or a tissue paper sheet, such as a conventional wet-pressed paper sheet, a structured sheet (e.g., TAD, ATMOS, etc.), or a textured sheet. The further sheets may be the same or different. The foam-formed sheets may also be the same or different from each other.

[0493] Figure 19 A cross-section is depicted through a multilayer product 130, which includes a sheet 131 formed of foam according to an embodiment of an absorbent web-based product according to the present disclosure. Figure 19 Product 130 is a double-layer product.

[0494] The foam-formed sheets 131 are in harmony with Figure 16 The product 100 depicted is manufactured in the same manner, but the sheet 131 is additionally embossed.

[0495] The multi-layer product 130 includes another layer 132. This additional layer 132 can be a nonwoven layer or a tissue paper layer, such as a conventional wet-pressed paper layer, a structured layer (e.g., TAD, ATMOS, etc.), or a textured layer.

[0496] Alternatively, a foam-formed sheet may be combined with two or more further sheets, or a selected number of other foam-formed sheets may be combined with a selected number of further sheets, each of which is a nonwoven sheet or a tissue sheet, such as a conventional wet-pressed paper sheet, a structured sheet (e.g., TAD, ATMOS, etc.), or a textured sheet. The further sheets may be the same or different. The foam-formed sheets may also be the same or different from each other.

[0497] Figure 20A cross-section is depicted through a multilayer product 140, which includes a sheet 141 formed of foam according to an embodiment of an absorbent web-based product according to the present disclosure. Figure 20 Product 140 is a double-layer product.

[0498] The foam-formed sheets 141 are in harmony with Figure 16 The product 100 depicted is manufactured in the same manner, but the sheet 141 is additionally embossed.

[0499] The multi-layer product 140 includes another layer 142. This additional layer 142 can be a nonwoven layer or a tissue paper layer, such as a conventional wet-pressed paper layer, a structured layer (e.g., TAD, ATMOS, etc.), or a textured layer. Relative to Figure 19 The difference in the embodiment is that the sheet 142 has also been embossed.

[0500] Alternatively, a foam-formed embossed or non-embossed sheet layer may be combined with two or more further embossed or non-embossed sheets, or a selected number of other foam-formed sheets may be combined with a selected number of further sheets, each of which is a nonwoven sheet or a tissue paper sheet, such as a conventional wet-pressed paper sheet, a structured sheet (e.g., TAD, ATMOS, etc.), or a textured sheet. The further sheets may be the same or different. The foam-formed sheets may also be the same or different from each other.

[0501] Figure 21 A cross-section is depicted through a multilayer product 150, which includes a foam-formed sheet 150 according to an embodiment of an absorbent web-based product of the present disclosure. Figure 21 The multi-layer product 150 includes another layer 152, and the two layers 151 and 152 are laminated together. Prior to lamination, similar to... Figure 16 The product 100 depicted in the image is made of foam forming sheets 151.

[0502] Figure 22 A cross-section is depicted through a multilayer product 160, which includes a foam-formed sheet 161 according to an embodiment of an absorbent web-based product of the present disclosure.

[0503] Figure 22 The multi-layer product 160 is a three-layer product including further layers 162 and 163. The three layers 161, 162, and 163 are laminated together. Before lamination, similar to... Figure 16 The product 100 depicted in the image is made of foam forming sheets 161.

[0504] Figure 23A cross-section is depicted through a multi-layer product 170, which includes foam-formed sheets 170 according to embodiments of absorbent web-based products of the present disclosure. The foam-formed sheets 171 are embossed. Figure 23 The multi-layer product 170 includes another layer 172, and the two layers 171 and 172 are laminated together. Prior to embossing and subsequent lamination, similar to... Figure 16 The product 100 depicted in the image is made of foam forming sheets 171.

[0505] Figure 24 A cross-section is depicted through a multi-layer product 180, which includes a foam-formed sheet 181 according to an embodiment of an absorbent web-based product of the present disclosure. The foam-formed sheet 181 is embossed. Figure 24 The multi-layer product 180 includes another layer 182, which is also an embossed layer, and the two layers 181 and 182 are laminated together. Prior to embossing and subsequent lamination, similar to... Figure 16 The product 100 depicted in the image is made of foam forming sheets 181.

[0506] Figure 25A This shows a micro-CT measurement image of the top side of a structured sheet (TAD sheet) manufactured according to a conventional TAD manufacturing process. The top side is not in contact with the imprint tape.

[0507] For comparison, Figure 25B A micro-CT measurement image of the top side of a foam-formed sheet manufactured according to this disclosure is shown. The top side is not in contact with the imprinting tape.

[0508] A comparison between the two images shows that the fiber distribution in the foam-formed sheets is much more uniform compared to the TAD sheets.

[0509] Similarly, Figure 26A This shows a micro-CT measurement image of the bottom side of a structured sheet (TAD sheet) manufactured according to a conventional TAD manufacturing process. The bottom side is in contact with the imprint tape.

[0510] For comparison, Figure 26B This image shows a micro-CT measurement of the underside of a foam-formed sheet manufactured according to the present disclosure. The underside is in contact with the imprint tape.

[0511] A comparison between the two images shows that the fiber distribution in the foam-formed sheets is much more uniform compared to the TAD sheets.

[0512] Figure 27AThe image shows a micro-CT measurement of the top side of a structured sheet (TAD sheet) manufactured according to a conventional TAD manufacturing process, and specifically depicts four segments A2, B2, C2 and D2, from which the cross-sections are visualized and examined in further detail.

[0513] Similarly, Figure 27B A micro-CT measurement image of the top side of a foam-formed sheet manufactured according to the present disclosure is shown, and four segments A1, B1, C1 and D2 are depicted, from which cross-sections are visualized and examined in further detail.

[0514] Similarly, Figure 28A This image shows a micro-CT measurement of the underside of a structured sheet (TAD sheet) manufactured according to a conventional TAD manufacturing process, with particular emphasis on four identical segments A2, B2, C2, and D2 from which samples were taken and further examined in detail. Figure 27A As shown.

[0515] Figure 28B The image shows a micro-CT measurement of the underside of a sheet of foam manufactured according to this disclosure, and depicts the same four segments A1, B1, C1, and D2 from which samples were taken and observed in further detail. Figure 27B As shown.

[0516] Figure 29A Microscopic CT measurement images of cross sections A2, B2, C2, and D2 taken through a structured sheet (TAD sheet) manufactured according to a conventional TAD manufacturing process are shown.

[0517] Figure 29B Micro-CT measurement images of cross sections A1, B1, C1, and D1 taken through a sheet formed from foam manufactured according to this disclosure are shown.

[0518] Example 1) Material The main starting materials and chemicals used in the following examples are listed below: Northern Bleached Cork Kraft Paper (NBSK) fluff pulp from Stora Enso; Northern Bleached Cork Kraft Paper (NBSK) wrapping pulp from Mercer; Simulsol SL10 (nonionic surfactant) from Seppic (France) Low viscosity (CAS 9004-32-4) carboxymethyl cellulose (CMC, binder) from Sigma-Aldrich (Germany); Carbocell MM8C (CMC, binder) from Lamberti Polyethylene glycol (PEG20000, a slip agent) with an average molecular weight of 20,000 g / mol from Sigma-Aldrich (Germany); and Maresin WS505 (wet strength resin) from Mare.

[0519] 2) method The following test methods are used to evaluate the manufactured web-based products. Before testing, the test samples are conditioned at 50% relative humidity and 23°C for at least 12 hours.

[0520] a) Base weight The basis weight is determined according to ISO 12625-6:2014.

[0521] b) Caliper value Measurements were performed using a precision micrometer (accuracy 0.001 mm) according to a modified method based on EN ISO 12625-3:2014. For this purpose, the distance between the sample and the fixed reference plate and the parallel pressure foot was measured. The diameter of the pressure foot was 35.7 mm. + 0.1mm (10.0cm) 2 (Nominal area). The applied pressure is 2.0 kPa. + 0.1 kPa. Pressure foot at 2.0... + It can move at a speed of 0.2 mm / s.

[0522] The available device is the thickness gauge type L&W SE050 (available from Lorentzen & Wettre in Europe).

[0523] Cut the finished product to be measured into 20x25cm slices and conditioned at 23°C and 50%RH for at least 12 hours.

[0524] For the measurement, a sheet is placed under the pressure plate and then lowered. The sheet thickness is then read after 5 seconds when the pressure has stabilized. This thickness measurement is repeated 9 times, and subsequent samples are processed in the same manner.

[0525] The average of the 10 values ​​obtained is taken as the thickness of a sheet of the finished product ("a sheet caliper value").

[0526] c) in g / cm 3 Density of the meter The density of a product based on its web length is calculated using the following formula: X = w / t X = density (g / cm³) 3 ) w = basis weight of the sheet (g / m³)2 ) t = Average thickness of the sheet (μm) d) Absorption capacity Determine the absorption capacity (in g / g) according to ISO 12625-8:2006.

[0527] e) Foam density and air content The foam density and air content of foam or fibrous foam are determined by placing the (fibrous) foam in a container of a predetermined volume and weighing the container filled with the (fibrous) foam. Specifically, the foam density (kg / m³) is determined by comparing the measured weight of the foam with the weight of water of the same volume as the foam, according to the following equations (1) and (2). 3 ) and air content (%): (1) (in percentage) (2) f) Dry solids content The dry solids content of the fibrous foam was determined immediately after molding and dehydration. The test sample was weighed, moistened, and dried, and the dry solids content was calculated according to the following equation (3): ×100 (in percentage terms) (3) Where m a It is the dry mass of the sample and m b This refers to the wet mass of the sample.

[0528] g) Rheology Rheological properties of fibrous foam were measured using a stress-controlled TA Instruments DHR-2 rheometer equipped with a blade geometry in a cup. The blades were made of stainless steel and had a commercially available 4-blade blade geometry with a diameter of 15 mm. The cup was 3D printed using stereolithography and had a diameter of 30 mm. The outer wall of the cup was vertically shaped to eliminate wall slippage during rheological measurements (see Carraretto et al., Physics of Fluid 2022, 43(11); Time-resolved rheology of coarse foam using 3D-printed fractal blades). The cup was placed in a temperature-controlled Peltier jacket that maintained the sample temperature at 25 °C during all rheological measurements. The fibrous foam sample was loaded into the cup with the aid of a syringe whose tip had been cut to ensure that the entire cup was filled with fibrous foam and that there were no air pockets within the sample. The air content of the fibrous foam sample was determined by weighing it before inserting the foam-filled cup into the rheometer. Subsequently, the blade geometry was lowered into the sample, so that each blade was vertically positioned in the center of the cup (16 mm from the bottom of the cup and the top surface of the foam sample). Figure XY shows an image of the blade measurement setup in the cup.

[0529] Three types of rheological measurements were performed on the fibrous foam samples: 1) Amplitude scan measurement from 0.01% to 100% strain amplitude at a constant angular frequency of 10 rad / s. 2) Frequency sweep measurement from 0.4 rad / s to 100 rad / s at a strain amplitude of 0.03%. 3) Shear rate scan measurement first from 0.1 s⁻¹ to 100 s⁻¹ -1 The shear rate (“upper curve”), then from 100 s -1 up to 0.01s -1 The shear rate (“lower curve”) Example 1: The method of this disclosure is used to produce absorbent web-based products.

[0530] The pulp (NBSK fluff pulp) is fed into a laboratory hammer mill (Kvarn H01, M-NR 4.122 4599, available from Kamas Industries AB) to produce defibrillated fluff pulp. The dried pulp fibers are pre-wetted by spraying water to a moisture content of 60% by weight within a Forberg paddle mixer.

[0531] The blend of components as described in Table 1 is introduced into a twin-screw extruder using a pump. The wetted fluff pulp is then introduced into the extruder via a weight feeder from Coperion K-Tron. Wet strength resin (Maresin WS505) is introduced after the fiber feed.

[0532] The twin-screw extruder was connected to a static die with a width of 250 mm and an opening (height) of 2.5 mm. The total throughput was set to 30 kg / h and the twin-screw speed was set to 2400 rpm.

[0533] The fiber consistency of the fibrous foam was measured to be 9% by weight and the total solids content was measured to be 10% by weight. After the preparation of the fibrous foam, the fiber volume fraction was calculated to be 0.0121.

[0534] Table 1. List of ingredients and quantities used in Example 1 The fibrous web, formed by static molding, is spread onto a standard air-penetrating-drying (TAD) fabric and discharged (dehydrated) through five consecutive vacuum chambers, with the vacuum level increasing (from -0.05 bar to -0.6 bar). The fabric is moved at a speed of 8 meters per minute.

[0535] Six samples were collected on TAD fabric and dried in a ventilated oven at 105°C until completely dry (approximately 2 hours).

[0536] After drying, the average basis weight and thickness of the product were measured, and the density was calculated. The results are shown in Table 2.

[0537] Table 2. Average properties of the prepared web-based products Example 2: The method of this disclosure is used to produce absorbent web-based products.

[0538] The pulp (NBSK fluff pulp) is fed into a laboratory hammer mill (Kvarn H01, M-NR 4.122 4599, available from KamasIndustries AB) to produce fiber-separated fluff pulp. The dried pulp fibers are pre-wetted by spraying water to a moisture content of 60% by weight within a Forberg paddle mixer.

[0539] A dilute suspension (2.5% by weight aqueous solution) of low viscosity CMC (LV-CMC; from Sigma-Aldrich) was used for fiber wetting.

[0540] A blend of the components described in Table 3 was introduced into a Pico-Mix foam mixer (commercially available from Hansa) to prepare a foam with an air content of 95% by volume. This foam was then introduced into a twin-screw extruder. A wetted fluff pulp was then introduced into the extruder via a weight feeder from Coperion K-Tron. A wet strength resin (Maresin WS505) was introduced after the fiber feed.

[0541] The twin-screw extruder was connected to a static die with a width of 250 mm and an opening (height) of 2.5 mm. The total throughput was set to 30 kg / h and the twin-screw speed was set to 2400 rpm.

[0542] The fiber consistency of the fibrous foam was measured as 20% by weight and the total solids content was measured as 10% by weight. After the preparation of the fibrous foam, the fiber volume fraction was calculated to be 0.0118.

[0543] Table 3. List of ingredients and quantities used in Example 2 The fibrous web, formed by static molding, is diffused onto a standard air-penetrating-drying (TAD) fabric and discharged (dehydrated) through five consecutive vacuum chambers, with the vacuum level increasing (from -0.05 bar to -0.6 bar). The fabric speed is 16 m / min.

[0544] Six samples were collected on TAD fabric and dried in a ventilated oven at 105°C until completely dry (approximately 2 hours).

[0545] After drying, the average basis weight and caliper readings of the product were measured, and the density was calculated. The results are shown in Table 4.

[0546] Table 4. Average properties of the prepared web-based products A comparison was made between the manufacture of sheets of cotton paper products according to the prior art (i.e., dry-creased cotton paper sheets and structured sheets) and sheets comprising absorbent web-based products according to this disclosure. Specifically, specific energy consumption was evaluated. The results are summarized in Table 5 below:

[0547] Table 5. Specific energy consumption of different manufacturing technologies It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed devices and systems without departing from the scope of this disclosure. Other aspects of this disclosure will become apparent to those skilled in the art upon consideration of the specification and the features disclosed herein. The specification and examples are intended to be considered exemplary only. Many additional variations and modifications are possible and are to be understood to fall within the framework of this disclosure.

Claims

1. A method for manufacturing an absorbent web-based product, comprising the following steps: - Preparing fibrous foam, wherein the preparation comprises dispersing fibers and one or more surfactants in a liquid and / or foam, wherein the fiber content is 5% to 60% by weight, the surfactant content is 0.02% to 1.20% by weight, and the liquid content is 40% to 95% by weight, and supplying and dispersing gas in the liquid and / or foam until a gas content of 64% or more by volume is achieved; - Form the fibrous foam into a foam layer; - Discharging the fibrous foam from the foam layer to form a fibrous web, wherein the fibrous web has a liquid content of 20% to 85% by weight; and - Dry the fibrous web to obtain an absorbent web-based product.

2. The method of claim 1, wherein feedback loop control is used to perform the dispersion of the gas in the liquid and / or foam, optionally comprising measuring at least one of the gas content, the density of the gas-liquid dispersion, and the electrical conductivity of the gas-liquid dispersion, and adding and dispersing the gas until at least one of the gas content, the density, and the electrical conductivity reaches a target value.

3. The method according to claim 1 or 2, wherein the preparation comprises supplying the gas and the liquid into a container such that the ratio between the amount of liquid supplied and the amount of gas supplied is within a predetermined range or reaches a predetermined value, and mechanically mixing in the container for at least a predetermined time or until foam parameters, such as foam height and / or gas content, reach a predetermined minimum threshold.

4. The method according to any one of the preceding claims, wherein the preparation comprises supplying a solid having a solid content of 5% to 60% by weight, and wherein at least 80% by weight of the solid is fiber.

5. The method according to any one of the preceding claims, wherein the liquid comprises at least 80% water by weight, and / or the gas used to prepare the fibrous foam comprises at least 95% air by volume.

6. The method according to any one of the preceding claims, wherein the fibrous foam comprises a liquid having at least 80% water by weight and / or a gas having at least 95% air by volume.

7. A method for manufacturing an absorbent web-based product, comprising the following steps: - A fibrous foam is prepared by supplying fibers and one or more surfactants to a liquid and / or foam and dispersing gas in the liquid and / or foam, thereby achieving a fiber volume fraction of 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less; - Form the fibrous foam into a foam layer; - Discharging the fibrous foam from the foam layer to form a fibrous web, wherein the fibrous web has a liquid content of 20% to 85% by weight; and - Dry the fibrous web to obtain an absorbent web-based product.

8. The method of claim 7, wherein the prepared fibrous foam comprises solids, and the solid volume fraction is 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less. Furthermore, at least 80% of the solid is fiber by weight.

9. The method according to claim 7 or 8, wherein the fiber content is 5% to 60% by weight, and / or the liquid content is 40% to 95% by weight, and the gas content is 64% or more by volume, optionally at least 70%, at least 75%, at least 80%, at least 85% or at least 90% by volume.

10. The method according to any one of the preceding claims, wherein the preparation comprises processing dried fibers or solids, moisturizing fibers or solids, liquid slurries or foams, and fibers into the fibrous foam.

11. The method of claim 10, wherein the processing is performed prior to the transport, or The processing is performed at least in part by a transport device that carries the fibrous foam to a forming device that forms the fibrous foam into the foam layer. in, Optionally, the processing is performed by the transport device.

12. The method according to claim 10 or 11, wherein the processing is performed by a processing apparatus and the discharge of the fibrous foam is performed by a discharge device. in, Optionally, one or more of the following components are part of an integral structural unit: the processing device, the transport device, the forming device, and the discharging device, wherein, optionally, the processing device includes the transport device.

13. The method of claim 12, wherein the processing includes increasing the pressure applied to the liquid slurry or the fibrous foam during transport in the downstream direction by the transport device, wherein the increase in pressure is optionally at least 0.1 bar and optionally an increase of 10 bar or less.

14. The method of claim 12 or 13, wherein the processing comprises applying a plurality of different pressure levels in succession in the downstream direction, wherein the pressure levels are optionally reduced two or more times and / or the pressure levels are optionally increased two or more times.

15. The method according to any one of claims 10 to 14, wherein the processing comprises at least one of: shearing, elongation and / or distribution mixing, defiberization, anti-flocculation, refining, dispersion, disintegration, alteration of fiber shape, heating, and addition of chemical additives.

16. The method according to any one of the preceding claims, wherein the preparation comprises supplying a rheology modifier.

17. The method according to any one of the preceding claims, wherein the discharge of the fibrous foam comprises mechanical discharge, optionally consisting of mechanical discharge.

18. The method according to any one of the preceding claims, wherein the absorbency-based product has a liquid content of 0.5% to 15% by weight, optionally 1% to 15% by weight, or 1% to 10% by weight, or 1.5% to 8% by weight, or 1.8% to 6.5% by weight, or 2% to 5% by weight. in, Optionally, the absorbency-based product has a water content of 0.5% to 10% by weight, optionally 1% to 10% by weight, or 1.5% to 8% by weight, or 1.8% to 6.5% by weight, or 2% to 5% by weight.

19. The method according to any one of the preceding claims, wherein the prepared fibrous foam has a solid content of more than 10% by weight, and optionally a fiber content of more than 10% by weight.

20. The method according to any one of the preceding claims, wherein forming the fibrous foam into a foam layer comprises making the fibrous foam planar.

21. The method according to any one of the preceding claims, comprising contacting the fibrous foam with at least one rotatable device and rotating the at least one rotatable device to transport the fibrous foam, optionally rotating the at least one rotatable device at 100 to 5000 revolutions per minute.

22. The method of claim 21, wherein rotation of the at least one rotatable device promotes at least a portion, or optionally all, of the fiber to be defibrinated.

23. The method of claim 21 or 22, wherein the fibrous foam is transported via at least one processing device selected from the following list: industrial mixer, screw kneader, industrial kneading machine, extruder, single-screw or twin-screw machine, single-screw or twin-screw continuous kneader, twin-screw or multi-screw machine, conical screw mixer, wherein the at least one processing device includes the at least one rotatable device.

24. The method according to any one of claims 21 to 23, wherein the rotatable device is housed in a housing, and the minimum distance between the rotatable device and the housing during rotation is in the range of 0.3 mm to 20 mm.

25. The method of claim 23, further comprising supplying at least one component selected from the following list to the fibrous foam during transport of the fibrous foam through the processing device: - A liquid, such as water, which may optionally contain one or more additives; - Gases, such as air; - Foam and / or liquid slurries; and - Solids, such as fibers, powders and / or granules.

26. The method according to any one of claims 21 to 25, wherein the rotation of the at least one rotatable device comprises rotating a twin-screw, a single-screw, or a multi-screw, and Transporting the fibrous foam by rotating the at least one rotatable device includes one or more of the following: accelerating the fibrous foam; This slows down the fibrous foam; Shear force is applied to the fibrous foam.

27. The method according to any one of claims 21 to 26, wherein the rotation of the at least one screw is performed in a screw assembly such as an extruder or a screw mixer, the screw assembly comprising a housing and the at least one screw, wherein in a cross section of the at least one screw perpendicular to the axis of rotation, the minimum distance between the at least one screw and the opposing inner surfaces of the housing is in the range of 1% to 20% of the outer diameter of the screw, optionally in the range of 0.3 mm to 20 mm.

28. The method according to any one of claims 21 to 27, wherein the at least one rotatable device comprises at least a first screw and a second screw, and the closest approach distance between the first screw and the second screw during rotation is in the range of 0.3 mm to 20 mm.

29. The method according to any one of claims 21 to 28, wherein the at least one rotatable device comprises a plurality of screws and at least one housing housing the plurality of screws, and the nearest approach distance between any of the plurality of screws and the relative inner surfaces of the at least one housing housing housing the at least one screw is in the range of 0.3 mm to 20 mm.

30. The method according to any one of the preceding claims, wherein the fibrous foam is displaced by a displacement pump prior to its formation, the displacement pump being optionally a rotary cam pump, a progressive chamber pump, a rotary gear pump, a piston pump, a diaphragm pump, a screw pump, a gear pump, a hydraulic pump, a rotary vane pump, a peristaltic pump, a rope pump, or a flexible impeller pump.

31. The method according to any one of the preceding claims, wherein the discharge comprises applying a vacuum to the foam layer at a constant pressure or a varying pressure, wherein the varying pressure is optionally a pressure that decreases at least once in the downstream direction of transport.

32. The method according to any one of the preceding claims, wherein the emission is performed by applying a vacuum to the foam layer in at least two consecutive stages, optionally to reduce the pressure.

33. The method according to any one of the preceding claims, wherein forming the fibrous foam into the foam layer is performed at least partially in a compression mold and / or a headbox and / or a cylindrical die forming device and / or a breast-sucking roller forming device, and / or The processing and / or formation of the foam layer is performed in a controlled pressure chamber. in, Optionally, the die is a slit die with an adjustable die gap, wherein the fibrous foam is processed into continuous fibrous webs or sheets on a moving continuous dewatering / conveyor unit.

34. The method according to any one of the preceding claims, comprising a step of preparing a slurry prior to the step of preparing the fibrous foam, the slurry comprising at least one component selected from the group consisting of: water, fiber, surfactant, binder and slip agent; wherein the preparation of the slurry is optionally performed at least in part in a high-consistency mixing apparatus.

35. The method according to any one of the preceding claims, wherein the drying is thermal drying, freeze drying, infrared drying, contact drying, impact drying, microwave drying, or ventilation drying.

36. The method according to any one of the preceding claims, wherein the preparation of the fibrous foam comprises supplying at least one surfactant or a mixture of surfactants, said surfactant optionally selected from anionic surfactants, cationic surfactants, amphoteric surfactants, amphoteric surfactants, and nonionic surfactants.

37. The method according to any one of the preceding claims, wherein the preparation of the fibrous foam comprises supplying at least one nonionic surfactant or a mixture of surfactants comprising at least one nonionic surfactant, said nonionic surfactant optionally being selected from the group consisting of: amine oxides, alkyl glucosides, alkyl polyglucosides, polyhydroxy fatty acid amides, alkoxylated mono- and di-fatty acid esters, alkoxylated fatty alcohols, alkoxylated alkylphenols, fatty acid monoglycerides, polyoxyethylene sorbitol, and sucrose esters.

38. The method of claim 37, wherein the at least one nonionic surfactant is selected from the group consisting of alkyl glucosides, alkyl polyglucosides and alkoxylated fatty alcohols, and the at least one nonionic surfactant is optionally an alkyl polyglucoside of general formula (1): R 1 -O-(R 2 ) n -H (1) in, R 1 It is a straight-chain or branched hydrocarbon group with 4 to 20 carbon atoms. R 2 It consists of hexose or pentose units. n is between 1 and 5.

39. The method according to any one of the preceding claims, wherein the preparation of the fibrous foam and the transport of the fibrous foam to the foam layer forming apparatus are facilitated by the same mechanical motion.

40. A method of manufacturing a final product, comprising the method according to any one of the preceding claims, and including at least one of the following steps after drying: web treatment, winding, refining, and conversion into a packaged or unpackaged final product.

41. An absorbent web-based product, which can be manufactured by the method according to any one of the preceding claims.

42. The absorbency-based web product according to claim 41, having a concentration of 5 g / m². 2 Up to 500 g / m 2 The base weight and 5 kg / m 3 Up to 200 kg / m 3 The density, and / or the variation σ of the basis weight as measured according to SCAN-P 92:09 is less than 20%, less than 15%, less than 10%, less than 5%, less than 3%, or less than 2% of the average basis weight of the absorbency based on the web of the product.

43. An absorbent web-based product comprising at least 70% by weight of fiber material based on the total weight of the absorbent web-based product. The absorbency of the web-based product is 5 g / m 2 Up to 500g / m 2 The base weight and 5 kg / m 3 Up to 200 kg / m 3 The density.

44. The absorbent web-based product of claim 43, wherein the change in basis weight σ measured according to SCAN-P 92:09 is less than 20%, less than 15%, less than 10%, less than 5%, less than 3%, or less than 2% of the average basis weight of the absorbent web-based product.

45. The absorbent web-based product according to claim 43 or 44, wherein the absorbent web-based product has an upper side and a lower side, and the density of the absorbent web-based product in the central region located in the thickness direction between the upper side and the lower side is lower than the density of the absorbent web-based product in the region located on the lower side and / or the upper side.

46. ​​The absorbent web-based product according to claims 43 to 45, comprising a surfactant.

47. The absorbent web-based product according to any one of claims 43 to 46, comprising one or more of the following (a) to (d): (a) at least 0.2% by weight of one or more binders, (b) at least 0.05% by weight of one or more rheology modifiers, (c) at least 0.01% by weight of one or more surfactants, and (d) At least 0.2% by weight of one or more slip agents, The total weight of each product based on the absorbency of the web material.

48. A multi-layered product comprising at least one layer made of the absorbent web-based product of any one of claims 43 to 47, optionally further comprising at least one nonwoven layer and / or at least one cotton paper layer, optionally conventional wet-pressed paper layer and / or structured layer and / or textured layer.

49. Equipment for manufacturing absorbent web-based products, comprising: - A fibrous foam preparation apparatus for preparing fibrous foam. - A foam layer forming apparatus for forming the fibrous foam into a foam layer; - A discharge device that discharges fibrous foam from the foam layer to form a fibrous web having a liquid content of 20% to 85% by weight; and - A drying apparatus that dries the fibrous web to obtain an absorbent web-based product. The fibrous foam preparation apparatus includes a supply device for supplying fibers, one or more surfactants, liquids, and gases, wherein the fiber content is 5% to 60% by weight, the surfactant content is 0.02% to 1.20% by weight, the liquid content is 40% to 95% by weight, and the gas content is 64% or more by volume.

50. The apparatus of claim 49, wherein the fibrous foam preparation apparatus includes a solid supply device for supplying solids, wherein the solid content is 5% to 60% by weight, and wherein at least 80% by weight of the solids are fibers.

51. The apparatus of claim 49 or 50, wherein the supply device supplies a liquid and / or foam, the surfactant, the fiber, and the gas dispersed in the liquid and / or foam, the liquid and / or foam comprising at least 80% water by weight, and / or the gas dispersed in the liquid and / or foam, the gas comprising at least 95% air by volume.

52. The apparatus according to any one of claims 49 to 51, wherein the fibrous foam preparation apparatus prepares a gas-liquid dispersion comprising a liquid content of at least 80% by weight of water and / or a gas content of at least 95% by volume of air.

53. Equipment for manufacturing absorbent web-based products, comprising: - A fibrous foam preparation apparatus for preparing fibrous foam. - A foam layer forming apparatus for forming the fibrous foam into a foam layer; - A discharge device that discharges fibrous foam from the foam layer to form a fibrous web having a liquid content of 20% to 85% by weight; and - A drying apparatus that dries the fibrous web to obtain an absorbent web-based product. The fibrous foam preparation apparatus thereof prepares fibrous foam having fibers, liquid and gas, and wherein the fiber volume fraction is 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less.

54. The apparatus of claim 53, wherein the fibrous foam preparation device prepares a fibrous foam having a solid content, wherein the solid volume fraction is 0.040 or less, optionally 0.035 or less, or 0.030 or less, or 0.025 or less, or 0.020 or less, or 0.015 or less, or 0.01 or less, or 0.005 or less. Furthermore, at least 80% of its solid content is fiber content.

55. The device according to claim 53 or 54, wherein the fiber content is 5% to 60% by weight, and / or the liquid content is 40% to 95% by weight, and the gas content is 64% or more by volume, optionally at least 70%, at least 75%, or at least 80%, or at least 85%, or at least 90% by volume.

56. The apparatus according to any one of claims 49 to 55, wherein the fibrous foam preparation apparatus comprises a processing apparatus for processing liquid slurry or foam and fibers into the fibrous foam.

57. The apparatus of claim 56, further comprising a transport device for transporting the liquid slurry and / or the foam and / or the fibrous foam to the foam layer forming apparatus. in, Optionally, the transport device performs at least a portion of the processing, wherein, optionally, the transport device performs the processing.

58. The apparatus according to claim 56 or 57, wherein one or more of the following components are part of an integral structural unit: the processing device, the fibrous foam preparation device, the transport device, the forming device, and the discharging device.

59. The device according to claim 57 or claim 58, as dependent on claim 57, wherein the transport device includes a pressurization section that increases the pressure applied to the liquid slurry or the fibrous foam during transport by the transport device in a downstream transport direction, wherein the pressure increase is optionally at least 0.1 bar and optionally an increase of 10 bar or less.

60. The device of claim 59, wherein the pressurization section successively applies a plurality of different pressure levels in the downstream direction, the pressure levels decreasing at least twice and / or increasing at least twice.

61. The apparatus according to any one of claims 56 to 60, wherein the processing apparatus performs at least one of the following: shearing, elongation and / or distribution mixing, defiberization, anti-flocculation, refining, dispersion, disintegration, fiber shape alteration, heating, and addition of chemical additives.

62. The apparatus according to any one of claims 49 to 61, wherein the fibrous foam preparation apparatus facilitates the preparation of the fibrous foam and the transport of the fibrous foam to the foam layer forming apparatus by the same mechanical motion, and / or wherein the fibrous foam preparation apparatus transports the fibrous foam to the forming apparatus.

63. The apparatus for manufacturing an absorbent web-based product according to any one of claims 49 to 62, further comprising one or more solid supply devices for supplying solids to the fibrous foam preparation apparatus, and one or more liquid supply devices for supplying liquids to the fibrous foam preparation apparatus to form the fibrous foam having a solid content of 5% to 60% by weight of the fibrous foam, optionally more than 10% by weight of the fibrous foam, and a liquid content of 40% to 95% by weight of the fibrous foam.

64. The apparatus for manufacturing an absorbent web-based product according to any one of claims 49 to 63, wherein the fibrous foam preparation apparatus includes a rheology modifier supply device for supplying a rheology modifier.

65. The apparatus for manufacturing absorbent web-based products according to any one of claims 49 to 64, wherein the discharging device is a mechanical discharging device.

66. The apparatus for manufacturing an absorbent web-based product according to any one of claims 49 to 65, wherein the fibrous foam preparation apparatus prepares the fibrous foam to have a solid content of more than 10% by weight and optionally a fiber content of more than 10% by weight.

67. The apparatus for manufacturing an absorbent web-based product according to any one of claims 49 to 66, wherein the fibrous foam forming apparatus causes the fibrous foam to be in a planar form.

68. The apparatus for manufacturing an absorbent web-based product according to any one of claims 49 to 67, comprising at least one rotatable device, the apparatus contacting the fibrous foam with the at least one rotatable device and rotating the at least one rotatable device to transport the fibrous foam, optionally rotating the at least one rotatable device at 100 to 5000 revolutions per minute.

69. The apparatus for manufacturing absorbent web-based products according to claim 68, wherein rotation of the at least one rotatable device facilitates at least one of the following: transport, mixing, defiberization, applying pressure to the fibrous foam, and establishing pressure on the fibrous foam.

70. The apparatus for manufacturing absorbent web-based products according to claim 68 or 69, comprising at least one processing device selected from the following list: industrial mixer, screw kneader, industrial kneading machine, extruder, single-screw or twin-screw machine, single-screw or twin-screw continuous kneader, twin-screw or multi-screw machine, conical screw mixer, wherein the at least one processing device includes the at least one rotatable device.

71. The apparatus for manufacturing absorbent web-based products according to any one of claims 68 to 70, comprising a housing housing the rotatable device, wherein the minimum distance between the rotatable device and the opposing inner surfaces of the housing is in the range of 0.3 mm to 20 mm.

72. The apparatus for manufacturing an absorbent web-based product according to claim 69 or 71, comprising a supply device that supplies at least one component selected from the following list while the fibrous foam is being transported through the processing device: - A liquid, such as water, which may optionally contain one or more additives; - Gases, such as air; - Foam and / or liquid slurries; and - Solids, such as fibers, powders and / or granules.

73. The apparatus for manufacturing absorbent web-based products according to any one of claims 69 to 72, wherein the at least one rotatable device is a twin-screw, single-screw, or multi-screw assembly, and The at least one rotatable device may optionally include one or more of the following sections: an acceleration section that accelerates the fibrous foam being transported through the processing device; a deceleration section that decelerates the fibrous foam being transported through the processing device; and a shearing and / or elongation application section that applies shearing and / or elongation forces to the fibrous foam.

74. The apparatus for manufacturing an absorbent web-based product according to any one of claims 69 to 73, comprising a screw assembly including a housing and the at least one screw, wherein in a cross section of the at least one screw perpendicular to the axis of rotation, the minimum distance between the at least one screw and the opposing inner surfaces of the housing is in the range of 1% to 20% of the outer diameter of the screw, optionally in the range of 0.3 mm to 20 mm.

75. The apparatus for manufacturing an absorbent web-based product according to any one of claims 67 to 74, wherein the at least one rotatable device comprises at least a first screw and a second screw, and the closest approach distance between the first screw and the second screw during rotation is in the range of 0.3 mm to 20 mm.

76. The apparatus for manufacturing an absorbent web-based product according to any one of claims 69 to 75, wherein the at least one rotatable device comprises a plurality of screws and at least one housing housing the plurality of screws, and the nearest approach distance between any of the plurality of screws and the opposing inner surfaces of the at least one housing housing housing the at least one screw is in the range of 0.3 mm to 20 mm.

77. The apparatus for manufacturing an absorbent web-based product according to any one of claims 49 to 76, comprising a displacement pump, optionally a rotary cam pump, a progressive chamber pump, a rotary gear pump, a piston pump, a diaphragm pump, a screw pump, a gear pump, a hydraulic pump, a rotary vane pump, a peristaltic pump, a rope pump, or a flexible impeller pump, said displacement pump displacing the fibrous foam prior to the formation.

78. The apparatus for manufacturing an absorbent web-based product according to any one of claims 49 to 77, wherein the discharge device applies a vacuum to the foam layer at a constant pressure or at a varying pressure, wherein the varying pressure is optionally a pressure that decreases at least once in the downstream direction of transport.

79. The apparatus for manufacturing an absorbent web-based product according to any one of claims 49 to 78, wherein the discharging device applies a vacuum to the foam layer in at least two consecutive stages, optionally at reduced pressure.

80. The apparatus for manufacturing absorbent web-based products according to any one of claims 49 to 79, wherein the foam layer forming apparatus comprises a compression mold and / or a headbox and / or a cylindrical die former and / or a chest-absorbing roller former.

81. An apparatus for manufacturing an absorbent web-based product according to claim 80 or any one of claims 56 to 79, such as that dependent on claim 80, wherein the processing apparatus and / or the foam layer forming apparatus are disposed in a controlled pressure chamber.

82. The apparatus for manufacturing an absorbent web-based product according to any one of claims 49 to 81, comprising a liquid slurry preparation device for preparing an intermediate mixture / slurry foam / slurry solution, the intermediate mixture / slurry foam / slurry solution comprising at least one component selected from the group consisting of: water, fiber, one or more surfactants, one or more binders, and one or more slip agents; The liquid slurry preparation apparatus may optionally include a high-consistency mixing device.

83. The apparatus for manufacturing absorbent web-based products according to any one of claims 49 to 82, wherein the drying apparatus is a thermal drying apparatus, a freeze drying apparatus, an infrared drying apparatus, a contact drying apparatus, an impact drying apparatus, a microwave drying apparatus, or a ventilated drying apparatus.

84. The apparatus for manufacturing absorbent web-based products according to any one of claims 49 to 83, comprising a surfactant supply device that supplies at least one surfactant or a mixture of surfactants, the surfactant optionally selected from anionic surfactants, cationic surfactants, amphoteric surfactants, amphoteric surfactants, and nonionic surfactants.

85. The apparatus for manufacturing absorbent web-based products according to any one of claims 49 to 84, comprising a temperature control device that controls the temperature inside at least one section of the apparatus.

86. The apparatus for manufacturing an absorbent web-based product according to any one of claims 49 to 85, comprising a controller for controlling the apparatus to perform the method according to any one of claims 1 to 39.

87. An apparatus for manufacturing a final product, the apparatus comprising the apparatus according to any one of claims 49 to 86, and at least one of the following components: a web processing device, a winding device, a refining device, and a conversion device for converting the final product into a packaged or unpackaged product.

88. Use of the apparatus according to any one of claims 49 to 87 for manufacturing absorbent web-based products.

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