Apparatus for manufacturing an absorbent core, particle redirection device and method for redirecting particles - Patents.com

Abstract

The present invention relates to an apparatus (1', 1") for manufacturing an absorbent core (C) for an absorbent product, said absorbent core (C) comprising a fibrous material (11, 11') and particles (200, 200') distributed through at least a part of said fibrous material (11, 11). The present invention also relates to a particle redirection apparatus (100) and a method for redirecting particles.

Description

[Technical field]

[0001] The present disclosure relates to an apparatus for manufacturing an absorbent core for an absorbent product. The present disclosure also relates to a particle redirection apparatus and a method for redirecting particles. [Background technology]

[0002] Absorbent products such as diapers, training pants, napkins, incontinence pads and the like contain an absorbent core, which usually comprises a soft fluff material such as ground wood pulp fibers. Various secondary materials are often incorporated into the absorbent fluff material, such as particles of superabsorbent polymers (SAPs), heat-activated adhesive fibers or odor-absorbing materials. Superabsorbent materials, also called superabsorbent particles, are polymers that have the ability to absorb many times their own weight in water and body fluids. The superabsorbent materials are either mixed with the fluff pulp fibers or added in a layered configuration between layers of fluff pulp.

[0003] One method of producing an absorbent core containing superabsorbent polymer is to form a first layer of absorbent fluff pulp, whereupon the superabsorbent polymer is sprinkled on top of the fluff pulp. A second layer of absorbent fluff pulp is then placed on top of the second material to complete the core. The absorbent core may further include two or more layers of superabsorbent polymer arranged between layers of absorbent fluff pulp fibers. This method produces a product with a layered configuration in which the superabsorbent polymer is concentrated in fairly discrete zones within the core.

[0004] Alternatively, the SAP particles are mixed with the first material (absorbent fluff pulp fibers) and distributed throughout the first material. It is further known to create absorbent products that include first and second layers, the first layer containing pure first material and the second layer containing a mixture of the first and second materials.

[0005] One method of producing an absorbent core for a product with a very uniform distribution of a second material within the core is disclosed in US Pat. No. 5,399,633. In the disclosure, an apparatus is presented for making an absorbent product containing a first material, such as absorbent fluff derived from wood pulp fibers. The absorbent fluff pulp is introduced into a vacuum forming chamber. A portion of the fluff pulp is deposited in a mold cavity, which is transferred through the forming chamber by a mat forming wheel, so as to form a layer of pure fluff pulp in the bottom of the mold cavity. A second material, such as superabsorbent particles or heat-activated adhesive fibers, is introduced into the forming chamber, such that the flows of the first and second materials collide in a mixing zone. As the mold continues, the second material advances through the forming chamber. From the mixing zone, a mixture of the first and second materials is deposited in the mold cavity, thereby filling it. The result is an absorbent core having a first layer formed by pure first material, and a second layer formed by a mixture of the first and second materials.

[0006] A more detailed description of a known device for manufacturing absorbent products of the design discussed will now be given with reference to Figure 1. Figure 1 shows the device 1, in which the pulp fibres from a defibrating unit are transported with the aid of air up to and through hoods 8a, 8b towards a mat-forming wheel 3. The mat-forming wheel 3 comprises a stationary suction box 2, in which a very low pressure prevails. The suction box faces said hood containing the pulp fibres. On the surface of the mat-forming wheel 3, air-permeable means such as a net or a perforated plate are provided. When said air-permeable means rotates under said hood in the direction indicated by the arrow 3b, the pulp fibres are pressed by the air flow towards the air-permeable means, forming a core of pulp fibres along the periphery of the mat-forming wheel in the form of a continuous mat. Said periphery may comprise dies for forming separate absorbent cores of different designs.

[0007] The core may further be formed into multiple layers through the use of multiple hoods. The core may be formed into discrete cores as described, or if the core is formed into a continuous mat, it may later be cut into the desired design.

[0008] A stream of superabsorbent particles (SAP) is added to the pulp fibres by injecting the superabsorbent particles through a pipe 4, i.e. a particle feed conduit, into one or more hoods 8a, 8b. After the last hood (hood 8b in the figure), the core formation is completed and the cores are held in one or more dies on the wheel by low pressure in a second stationary suction box 5. After passing said second suction box 5, the cores are transferred to a transfer drum 9 where they may be compressed, for example using mechanical pressure applied to the cores while passing over the transfer drum. Finally, the cores are transferred to a conveyor 16 for further processing or packaging. The transfer from the mat-forming wheel 3 to the conveyor 16 may be done without a transfer drum.

[0009] The final product may be composed of a number of cores, whereby the manufacturing assembly for said final product is composed of two or more mat-forming wheels 3, each of which forms a core, on which two or more resulting cores are assembled into the final product.

[0010] This method of manufacturing an absorbent core provides a core with an even layer of highly absorbent particles throughout the mold.

[0011] However, it may be preferable to have highly absorbent particles in specific areas of the mold to create a highly absorbent zone within the core, for example at the front or back of the core.

[0012] US Patent No. 5,399,633 shows a method and apparatus for intermittently adding particulate material to a substrate that is precisely positioned within the substrate, but alternative solutions are needed.

[0013] [Patent Document 1] U.S. Pat. No. 5,447,677 [Patent Document 2] European Patent Application Publication No. 1053729 Summary of the Invention [Problem to be solved by the invention]

[0014] It would be desirable to provide an alternative system that allows for the distribution of particles in specific areas of the absorbent core and at the same time is a flexible system. [Means for solving the problem]

[0015] According to a first aspect of the present disclosure, there is provided an apparatus for manufacturing an absorbent core for an absorbent product, said absorbent core comprising fibrous material and particles dispersed throughout at least a portion of said fibrous material, said apparatus comprising: - a movable mat-forming device comprising at least one mold, said movable mat-forming device being movable in a machine direction; - a passageway for directing the mixture of the fibrous material and the particles toward at least one mold to deposit at least one layer of the mixture of the fibrous material and the particles into the at least one mold; a particle supply conduit having an opening inside said passage.

[0016] The apparatus further includes a particle redirector positioned adjacent to the opening of the particle supply conduit, the particle redirector being pivotable in or against the machine direction about a pivot axis extending transversely to the machine direction, thereby redirecting the particles to at least one region on the at least one mold.

[0017] By having a particle redirector pivotable about a pivot axis adjacent to an opening of the particle supply conduit, the particle redirector can redirect particles from the particle supply conduit to at least one specific region on the mold, where adjacent to the opening means that the particle redirector is positioned in close proximity to the opening.

[0018] The areas on the mold that are to receive the particles may be predefined, or the areas may be redefined, i.e., changing, throughout the process of making the absorbent core.

[0019] The mat-forming device may be a mat-forming wheel or a mat-forming belt. Both may comprise a continuous die extending along the periphery of the device. A continuous die is utilized when the fibers deposited on the air permeable means are to be used to form a continuous layer, which is then cut into the appropriate size and shape to form the individual absorbent cores of the absorbent product. Alternatively, a series of separate dies may be arranged along the periphery of the mat-forming device. The separate dies are used to directly form cores of specific shapes and dimensions to form the absorbent cores of the absorbent product. One or more dies on the moving mat-forming device move along the machine direction, and while the dies are moving, the particle redirector may pivot in a first step either in the same direction as the moving mat-forming device or in the opposite direction. Depending on the pivoting speed and the pivoting direction, the particles can advance to one or more specific areas on the dies. Once the mould is filled with particles in one or more specific areas, the particle redirector can move in a second step in the opposite direction to the first step or in the same direction as the starting position, so that the particle redirector is ready to fill the mould following the first mould, if the mat-forming device comprises a series of separate moulds. The particles can be distributed in the same area in all the moulds or can be different from mould to mould. Alternatively, several moulds, for example 10 moulds, can be filled in the same area and then the next 10 moulds are filled with particles in different areas. The same is true for a continuous mould, but the particles are then oriented in different positions on the continuous mould, so that when the individual absorbent cores are cut, they have the particles in their defined areas.

[0020] A passageway for directing the at least one mixture of fibrous material and particles toward the die may be formed by the hood.

[0021] The opening of the particle supply conduit is located at a certain distance from the moving mat-forming device so that the fibrous material and the particles can mix before arriving at the mold. For example, the distance may be 100 cm to 200 cm, more preferably 130 cm to 170 cm. Thus, the reoriented particles may be mixed with the fibrous material before being placed in the mold.

[0022] In one exemplary embodiment, the particle redirector includes a base having a convex surface and an opposing concave surface and a periphery. A first imaginary plane is aligned along the pivot axis and bisects the base into two halves such that a cross section of the base taken along the first imaginary plane is U- or V-shaped. A second imaginary plane is perpendicular to the first imaginary plane, and the first and second imaginary planes intersect along the pivot axis. A third imaginary plane bisects the base into two halves. The third imaginary plane is perpendicular to the first and second imaginary planes, and the third imaginary plane intersects the first imaginary plane along a first axis and intersects the second imaginary plane along a second axis. The particle redirector includes at least a first flange and a second flange extending from the convex surface on each side of the first imaginary plane and essentially parallel to the first imaginary plane, the concave surface or the convex surface together with the flanges directing the particles towards the die, and the pivot axis is positioned at a fixed distance along the first imaginary plane from the center of gravity or the center of gravity of the particle redirector.

[0023] Depending on how the surface of the particle redirector, i.e. the concave surface or the convex surface, together with the flange, is positioned in relation to the opening of the particle supply conduit in the first position, i.e. the starting position, the particles can be directed to at least one region on the mold. By selecting a particular starting position of the particle redirector, the region in which the particles will be present can be determined.

[0024] The pivot may be placed at the center of gravity of the particle redirector since it can then rotate smoothly. However, having the pivot at a fixed distance from the center of gravity will still work. The advantage of having the pivot at the center of gravity is that the motor loads will be lower than if it were placed at a fixed distance from the center of gravity. The forces on the mechanical structure, e.g. bearings, will also be lower if the pivot is placed at the center of gravity.

[0025] The base may have a generally oval shape. The base may also have a generally round shape or any suitable shape. The two flanges may be disposed at the same distance from the first imaginary plane.

[0026] In one exemplary embodiment, a first imaginary plane bisects the base into two equal halves and the third imaginary plane bisects the base into two equal halves. Thus, the particle redirector may be symmetric on each side of the first and third imaginary planes.

[0027] In one exemplary embodiment, the particles are superabsorbent particles, heat activated adhesive particles, or odor absorbing particles.

[0028] In one exemplary embodiment, the fibrous material is a soft fluff material, such as ground wood pulp fibers.

[0029] In one exemplary embodiment, the third flange extends from the convex surface aligned with the first imaginary plane and is parallel to the first imaginary plane. The third flange is disposed between the first and second flanges and serves to direct particles in the same manner as the first and second flanges. The particle orienting device is not limited to having two or three flanges, but may have more, for example, four or five flanges. The flanges may have a rounded outer contour or a rectangular shape or any other suitable shape when viewed normal to the first imaginary plane.

[0030] In one exemplary embodiment, a fourth flange extends from the convex surface aligned with the third imaginary plane between the first flange and the second flange and is parallel to the third imaginary plane. This fourth flange connects the first and second flanges together and also connects the third flange together if there is a third flange between the first and second flanges. The fourth flange may add stability to the particle redirector.

[0031] In one exemplary embodiment, the pivot axis in a cross section taken along the third imaginary plane is located at a substantially equal predetermined distance from the highest point of each of the first, second and / or third flanges and from an outer point of the periphery on each side of the first imaginary plane. The distance between the pivot axis and the highest point of the first flange is therefore the same as the distance between the pivot axis and the second or third flange. The distance between the pivot axis and one of the outer points is the same as the distance between the pivot axis and the highest point of the flange. That is, in a cross section taken along the third imaginary plane, a partial circle can be drawn from the first outer point of the periphery through the highest point of each flange to the second outer point of the periphery on the opposite side of the first imaginary plane. The radius of the partial circle is equal to the predetermined distance.

[0032] In one exemplary embodiment, each of the first, second and / or third flanges has a curved exterior shape extending from the highest point of the respective flange toward the convex surface as viewed normal to the first imaginary plane. The curved exterior shape may be symmetric on both sides of the third imaginary plane. Having a curved exterior shape prevents fibrous material from building up on the flanges and later dropping into the mold, which may create rigid regions in the core.

[0033] In one exemplary embodiment, the particle redirector has an exterior contour formed by first, second and / or third flanges together with a base that in part follows the shape of an imaginary surface of an imaginary ellipsoid.

[0034] In one exemplary embodiment, at least a part of the particle redirector protrudes into the opening of the particle supply conduit or the particle redirector is located close to the opening of the particle supply conduit, in this way it is achieved that most of the particles coming from the particle supply conduit impinge on the particle redirector to direct the particles towards the die.

[0035] In one exemplary embodiment, there is a gap with a predetermined distance between the wall of the particle supply conduit, i.e., the end of the particle supply conduit, and the first and second and / or third flanges when the particle redirector pivots and passes through the particle supply conduit. The predetermined distance is preferably minimized to reduce uncontrolled airflow in unwanted directions. The predetermined distance may be preferably 1 mm to 4 mm, more preferably 2 mm.

[0036] In one exemplary embodiment, the opening of the particle supply conduit has a shape and / or diameter such that the outer contour of the particle redirector is free to pivot adjacent to the particle supply conduit or at least partially inside the particle supply conduit.

[0037] In one exemplary embodiment, the first and second flanges are disposed at a distance from each other, which is equal to, smaller than, or larger than the inner diameter opening of the particle supply conduit. When the distance is equal to or larger than, the particles will impinge on the convex surface between the flanges when the convex surface is disposed facing the opening of the particle supply conduit, i.e., when the second surface faces the opening of the particle supply conduit. This is especially the case when a portion of the flanges protrudes into the opening. When the distance between the flanges is smaller, some particles may impinge on the convex surface between the first flange and the periphery and / or the convex surface between the second flange and the opposite periphery.

[0038] In one exemplary embodiment, the maximum width of the base of the particle redirector in a cross section taken along said first imaginary plane is equal to or greater than the inner diameter of the particle supply conduit, ensuring that most particles impinge on the base and can be directed by either the convex or concave side of the base.

[0039] In one exemplary embodiment, the first axis of the particle redirector is aligned with a central axis of the particle supply conduit, thus ensuring that the particle redirector is aligned with the particle supply conduit.

[0040] In one exemplary embodiment, the particle redirector includes a shaft connecting element extending along the pivot axis adapted to receive a shaft connectable to the shaft connecting element for pivoting the particle redirector about the pivot axis.

[0041] In one exemplary embodiment, the particle redirector is pivotable about the pivot axis by a shaft connected to the particle redirector that is rotatably supported in the passageway.

[0042] In one exemplary embodiment, the particle redirector is attached to a hood that defines the passageway.

[0043] In an exemplary embodiment, the particle redirector is pivotable about the pivot axis by a motor. The motor may be an AC servo motor. The motor may be operated by a programmable position control system, e.g. a computer. The motor is therefore programmable so that the particle redirector can take different starting positions so that the particles are distributed in one or more specific areas of the mould during the process. This may be the same one or more areas for all moulds or may be different for each mould. The AC servo motor may for example be set so that the particle redirector has for example 18 freely programmable positions, i.e. 18 starting positions. The limitation is that unusable positions can be avoided. However, the motor and the position control system are not limited thereto. The motor may be freely programmed so that the particle redirector can be positioned in any position about the pivot axis, i.e. at any angle to the central axis of the feed conduit before starting the pivot. The programmable position control system may also be set to a specific pivot direction and pivot speed so that the particle redirector pivots in a predefined direction and speed relative to the mat forming device.

[0044] According to another aspect of the present disclosure, there is provided a particle redirector including a base having a convex surface and an opposite concave surface and a periphery. A first imaginary plane is aligned along the pivot axis and bisects the base into two halves such that a cross section of the base at the first imaginary plane is U- or V-shaped. A second imaginary plane is perpendicular to the first imaginary plane, and the first and second imaginary planes intersect along the pivot axis. A third imaginary plane bisects the base into two halves, and the third imaginary plane is perpendicular to the first and second imaginary planes, and the third imaginary plane intersects the first imaginary plane along a first axis and intersects the second imaginary plane along a second axis. The particle redirector includes at least a first flange and a second flange extending from the convex surface on each side of the first imaginary plane and essentially parallel to the first imaginary plane. The pivot axis is located at the centre of gravity of the particle redirector or at a fixed distance from the centre of gravity along the first imaginary plane. The same advantages as described for the particle redirector in the apparatus above apply.

[0045] In one exemplary embodiment, a first imaginary plane bisects the base into two equal halves and the third imaginary plane bisects the base into two equal halves. In this manner, the particle redirector may be symmetric on each side of the first and third imaginary planes.

[0046] In one exemplary embodiment, a third flange extends from the convex surface aligned with the first imaginary plane and is parallel to the first imaginary plane. The third flange is disposed between the first flange and the second slack and serves to direct particles in the same manner as the first and second flanges. The particle orienting device is not limited to having two or three flanges, but may have more, for example, four or five flanges. The flanges may have a rounded outer contour or a rectangular shape or any other shape when viewed normal to the first imaginary plane.

[0047] In one exemplary embodiment, a fourth flange extends from the convex surface aligned with the third imaginary plane between the first flange and the second flange and is parallel to the third imaginary plane.

[0048] In one exemplary embodiment, the pivot axis in a cross section taken along the third imaginary plane is located at a substantially equal predetermined distance from a highest point of each of the first, second and / or third flanges and from an outer point of the periphery on each side of the first imaginary plane.

[0049] In one exemplary embodiment, each of the first, second and / or third flanges has a curved exterior shape extending from a highest point of the respective flange toward the convex surface when viewed normal to the first imaginary plane. Having a curved exterior shape prevents fibrous material from building up on the flanges and later falling into the mold, which may create rigid regions in the core.

[0050] In one exemplary embodiment, the particle redirector has an exterior contour formed by first, second and / or third flanges together with a base that in part follows the shape of an imaginary surface of an imaginary ellipsoid.

[0051] In one exemplary embodiment, the first and second flanges are positioned a fixed distance from each other.

[0052] In one exemplary embodiment, the base of the particle redirector has a maximum width in a cross section taken along said first imaginary plane.

[0053] In one exemplary embodiment, the particle redirector includes a shaft connecting element extending along the pivot axis adapted to receive a shaft connectable to the shaft connecting element for pivoting the particle redirector about the pivot axis.

[0054] The advantages and clarifications of the above features with respect to the particle redirector itself are the same as those made to the particle redirector within the apparatus described above.

[0055] According to another aspect of the disclosure, a method is provided for redirecting particles fed from an opening of a particle feed conduit inside a passageway, directing said particles towards at least one die on a moving mat-forming device moving in a machine direction. The redirection is performed by a particle redirector disposed adjacent to said opening. The particle redirector is pivotable about a pivot axis extending transversely to the machine direction of the moving mat-forming device. The method includes pivoting the particle redirector about said pivot axis along and / or against the machine direction, thereby redirecting said particles to at least one region on the at least one die. By having a particle redirector pivotable about a pivot axis, the particle redirector can redirect particles from a particle feed conduit to a specific predefined region or regions on the die. The mat-forming device may be a mat-forming wheel or a mat-forming belt. Both may comprise a continuous die extending along the periphery of the device. A continuous die is utilized when the fibers deposited on the air permeable means are to be used to form a continuous layer, which is then cut into the appropriate size and shape to form the individual absorbent cores of the absorbent product. Alternatively, a series of separate dies may be arranged along the periphery of the mat-forming device. The separate dies are used to directly form cores of specific shapes and dimensions to form the absorbent cores of the absorbent product. The dies on the moving mat-forming device move along the machine direction, and while the dies are moving, the particle redirector may pivot in a first step either in the same direction as the moving mat-forming device or in the opposite direction. Depending on the pivoting speed and the pivoting direction, the particles can advance to one or more specific areas on the die. Once the die is filled with particles in a specific area, the particle redirector may move in a second step in the opposite direction to the first step, or in the same direction as the first step, if the mat-forming device comprises a series of separate dies, to a position such that the particle redirector is ready to fill the die following the first die. The particles can be distributed in the same area throughout the dies, or they may vary from die to die. Alternatively, multiple molds, for example 10 molds, are filled in the same area and the next 10 molds are filled in different areas with particles.The same is true for a continuous die, but the particles are oriented at different locations on the continuous die so that when the individual absorbent cores are cut, they have the particles in their predetermined areas.

[0056] In one exemplary embodiment, the particle redirector is a particle redirector as described above.

[0057] In one exemplary embodiment, the particle redirector pivots from a starting position in a first step at a first speed in the same direction as the mat-forming device or in the opposite direction to the mat-forming device so that the particles are directed to a certain area on the mold. The advantage of doing this is that the particles can be distributed to a certain area or areas of the mold, for example at one end of the mold, for example at the front, if the front of the absorbent core advances first in the machine direction. Due to the pivoting, the particles can be concentrated in one area other than other areas of the mold. Thus, the particles are directed to a certain area, i.e., they follow the intended area on the mold when the mold is moving in the machine direction of the mat-forming device. In a conventional particle distribution, for example a highly absorbent particle distribution, the particles should be distributed uniformly in the mold without a pivotable particle redirector. The first speed can be adapted so that the particles close to the mold advance at the same speed as the mat-forming device, i.e., at the speed of the mold. For example, if the particle redirector pivots in the same direction at a first speed that gives the particles closest to the mold the same speed and direction as the mold, the particles will be positioned within the mold in a given area. The starting position of the particle redirector itself may be changed to vary the area of ​​the particles within the mold. The particle redirector may rotate at a slower or faster speed than the mat forming device and / or pivot in the same or opposite direction as the mat forming device. This provides a very flexible system, where particles can be positioned in any area within the mold, and the area can vary from mold to mold or be the same for multiple molds.

[0058] In one exemplary embodiment, in the second step, the particle redirector is pivoted in a direction opposite to the first direction at a second speed that is faster than the first speed. The advantage of doing this is that when the particles are distributed in a certain area, the particle redirector pivots back to the starting position so that when, for example, the first die receives the particles in its defined area, the particle redirector is ready to distribute the particles to the same or another area on the next die. The same thing happens if there is only one die and it creates one long core that is later separated into separate cores, and certain areas will have more particles than others.

[0059] Generally, all terms used throughout this disclosure should be interpreted according to their ordinary meaning in the art, unless expressly defined otherwise herein. All references to "a / an / the [element, device, component, means, step, etc.]" should be openly interpreted as a reference to at least one instance of that element, device, component, means, step, etc., unless expressly stated otherwise.

[0060] Other objects, features, and advantages of the exemplary embodiments of the present disclosure will become apparent from the following detailed disclosure, as well as from the drawings. Those skilled in the art will readily recognize that different features of the exemplary embodiments may be combined to produce embodiments other than those expressly described below, without departing from the scope of the present disclosure.

[0061] The above, as well as additional objects, features and advantages of the present disclosure, will be better understood through the following illustrative and non-limiting detailed description of exemplary embodiments of the invention, with reference to the accompanying drawings in which like reference numerals are used for similar elements, and in which: [Brief description of the drawings]

[0062] [Figure 1] 1 shows a schematic diagram of a conventional absorbent core manufacturing apparatus; [Diagram 2] 1 illustrates a schematic representation of an embodiment of a manufacturing apparatus according to one aspect of the present disclosure, comprising a mat-forming wheel; [Diagram 3] 1 shows a schematic representation of an embodiment of a manufacturing apparatus according to one aspect of the present disclosure, comprising a mat-forming belt. [Figure 4] 3 shows a perspective view of a portion of FIG. 2. [Diagram 5] 2 and 4, but showing the AA section with the particle redirector viewed from the side. [Figure 6] 6 shows a perspective schematic diagram of the particle redirector embodiment of FIGS. 2-5 connected to a motor and a connecting plate; FIG. [Figure 7] This shows a cross section taken along line BB in FIG. [Figure 8a] 8 shows a perspective view of the particle redirector in FIGS. 5, 6 and 7 with a downwardly facing flange according to one embodiment of the present disclosure. [Figure 8b] FIG. 8b shows a perspective view of the particle redirector of FIG. 8a pivoted 180 degrees with the flange facing upwards. [Figure 8c] 8a and 8b taken along a third imaginary plane with the flange facing upwards. FIG. [Figure 8d] 8a and 8b, shown diagrammatically as viewed normal to a first imaginary plane, with the flange pointing upwards. [Figure 9a] Figures 8a and 8b show schematic views of the particle redirector in different positions of the manufacturing apparatus in Figure 7, i.e. cross section BB in Figure 5, but with the particle redirector from the side. Figure 9a' shows an enlarged view of the particle redirector in Figure 9a, and Figure 9a" shows in perspective the filled mould on the mat-forming wheel in Figure 9a. [Figure 9b] Fig. 8a and 8b show schematic views of the particle redirector in different positions of the manufacturing apparatus in Fig. 7, i.e. cross section BB in Fig. 5, but with the particle redirector from the side. Fig. 9b' shows an enlarged view of the particle redirector in Fig. 9b and Fig. 9b" shows a perspective view of the filled mould on the mat-forming wheel in Fig. 9b. [Figure 9c]8a and 8b show schematic views of the particle redirector in different positions of the manufacturing apparatus in Fig. 7, i.e. cross section BB in Fig. 5, but with the particle redirector from the side. Fig. 9c' shows a close-up of the particle redirector in Fig. 9c, and Fig. 9c" shows a perspective view of the filled mould on the mat-forming wheel in Fig. 9c. [Figure 9d] 8a and 8b show schematic views of the particle redirector in different positions of the manufacturing apparatus in Fig. 7, i.e. cross section BB in Fig. 5, but with the particle redirector from the side. Fig. 9d' shows an enlarged view of the particle redirector in Fig. 9a and Fig. 9d" shows a perspective view of the filled mould on the mat-forming wheel in Fig. 9d. [Figure 9e] 8a and 8b show schematic views of the particle redirector in different positions of the manufacturing apparatus in Fig. 7, i.e. cross section BB in Fig. 5, but with the particle redirector from the side. Fig. 9e' shows an enlarged view of the particle redirector in Fig. 9e, and Fig. 9e" shows a perspective view of the filled mould on the mat-forming wheel in Fig. 9e. [Figure 9f] 8a and 8b show schematic views of the particle redirector in different positions of the manufacturing apparatus in Fig. 7, i.e. cross section BB in Fig. 5, but with the particle redirector from the side. Fig. 9f' shows a close-up of the particle redirector in Fig. 9f, and Fig. 9f" shows a perspective view of the filled mould on the mat-forming wheel in Fig. 9f. [Figure 10] FIG. 8 shows a perspective view of an enlarged view of the particle redirector and particle supply conduit in FIGS. [Figure 11a] 2A illustrates a schematic diagram of a second embodiment of a particle redirector according to an aspect of the present disclosure; [Figure 11b] 2A illustrates a schematic diagram of a second embodiment of a particle redirector according to an aspect of the present disclosure; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0063] All figures are very schematic and not necessarily to scale, the figures show only those parts necessary to clarify the invention, other parts being omitted or only suggested.

[0064] Various aspects of the disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. However, exemplary embodiments may take many different forms and should not be construed as being limited to the details of the embodiments set forth herein, but rather these embodiments are provided for the sake of thoroughness and completeness. Like reference characters refer to similar elements throughout the description.

[0065] The present disclosure refers to methods of making absorbent cores that can be used in disposable absorbent hygienic products, meaning products that are not intended to be laundered after use or otherwise repaired or reused as absorbent products, e.g., they are intended to be discarded after a single use and may be configured to be recycled, composted, or otherwise disposed of in an environmentally compatible manner. By "absorbent product" is meant a product that absorbs or is adapted to absorb bodily fluids, such as those containing urine and / or blood, and / or solid waste.

[0066] "Absorbent products", also called disposable absorbent hygiene products or articles, refer to consumable products that absorb and contain body exudates, and more specifically, products that are placed on or in close proximity to the wearer's body to absorb and contain various exudates discharged from the body. Absorbent articles, also called absorbent hygiene products, include, for example, diapers, sanitary napkins, and incontinence pads. Diapers include, for example, all-in-one diapers, pant diapers, and belt diapers. Diapers can be baby, toddler, or adult diapers.

[0067] In FIG. 2, an apparatus 1' for manufacturing absorbent cores of liquid absorbent products according to various embodiments of the present invention is disclosed.

[0068] The apparatus is similar to that disclosed in FIG. 1 and therefore the various parts of the equivalent apparatus have been given the same reference numbers as the parts which are generally equivalent.

[0069] The fibrous material, i.e. pulp fibres 11, from the defibrating unit (not shown), also called cellulose fluff pulp, is delivered with the aid of an air flow into forming chambers 8a, 8b, here called hoods. Each of the forming chambers, i.e. hoods 8a, 8b, forms a passage 7. A mat-forming wheel 3 for forming the absorbent product core C is arranged to rotate under the opening downstream of each hood 8a, 8b and is sealed connected with said hoods. The mat-forming wheel 3 rotates in the direction indicated by the arrow 3a, which is also the machine direction MD. In the embodiment according to Fig. 2, the device comprises two hoods 8a and 8b. Facing each hood opening, a first suction box 2, which does not rotate, is arranged inside the mat-forming wheel 3. Air permeable means are arranged along the periphery of the mat-forming wheel 3 in order to allow air to pass from said suction box 2 radially inwards of the mat-forming wheel. To draw air from the hoods 8a, 8b through the air permeable means, a low pressure prevails in the first suction box 2, generating the radially inward passing air flow 15. The low pressure may be generated by means of a fan, not shown.

[0070] The fibres 11 delivered to the hoods 8a, 8b are advanced by the flow 15 towards the periphery of the mat-forming wheel 3 and deposited there against an air permeable means, which may consist of any net, plate provided with holes, fibres or the like (not shown).

[0071] The mat-forming wheel 3 may comprise a continuous die extending along the circumference of the mat-forming wheel. A continuous die is utilized when the fibres deposited on the air permeable means are to be used to form a continuous layer, which is subsequently cut into the appropriate size and shape to form the individual absorbent cores of the absorbent product. In the figures, an example is shown in which a series of separate dies 6 are arranged along the circumference of the mat-forming wheel 3. The separate dies are used to directly form cores of specific shapes and dimensions to form the absorbent cores of the absorbent product. Variations of dies are known in the art and need not be discussed further here.

[0072] Pulp fibers 11 are often combined with other fibers or particles with specific properties as added ingredients to form the absorbent core of an absorbent product. Such added ingredients may be superabsorbent particles, heat activated adhesive particles, or odor absorbing particles. In Figure 2, superabsorbent particles 200 are added. However, if other particles are added, they can be added in the same manner as superabsorbent particles 200 described with respect to Figures 2-11f.

[0073] Superabsorbent particles are made from a type of absorbent polymeric material, called superabsorbent polymers, that chemically binds large amounts of fluid onto the absorbent to form a fluid-retaining gel.

[0074] Superabsorbent polymers are well known in the field of absorbent products and are used to serve to improve the absorption properties of such products. Superabsorbent polymers are comprised of water-swellable and water-insoluble polymers that can absorb large amounts of fluid when they form a hydrogel, such as being able to absorb at least 5 times its weight of 0.9% saline when measured according to method NSWP241.0.R2(15). Superabsorbent polymers may be inorganic or organic cross-linked hydrophilic polymers such as polyvinyl alcohol, polyethylene oxide, cross-linked starch, guar gum, xanthan gum, cross-linked polyacrylates, and the like. The polymers may be in the form of, for example, powders, granules, particulates, films, foams, and fibers. Upon contact with fluid, such superabsorbent polymers swell by absorbing the fluid into their structure. Generally, superabsorbent polymers can rapidly absorb insulted fluids into such articles, maintain such fluids from leaking, and serve to provide a dry feeling even after the insult of the fluid.

[0075] In the hood 8 a, only the pulp fibers 11 are used to form the first layer of the produced core C in the mould 6 .

[0076] The second hood 8b is equipped with a particle supply conduit 4 having an opening 4a through which the added superabsorbent particles 200 are injected. In the region of the opening 4a of the particle supply conduit 4, a particle redirector 100 is attached to the hood 8 via a connecting plate 300.

[0077] See also Figures 4 and 5. Figure 4 shows a part of Figure 2 in perspective, i.e. Figure 4 shows the mat-forming wheel 3 with its second hood 8b and its mould 6 in perspective, i.e. the first hood 8a has been removed. Figure 5 shows the section AA in Figure 2 with the particle redirector seen from the side, i.e. not in section.

[0078] The superabsorbent particles 200 have been redirected to one or more predefined regions on the mold 6 by the particle redirector 100. This is further described and shown in Figures 9a-9f.

[0079] The superabsorbent particles 200 are mixed with the pulp fibers 11 in the area below the particle redirector 100 and they are added to a flow 15 that is directed towards the die 6 on the mat forming wheel 3 as a mixture of pulp fibers 11 and added particles. Due to the particle redirector 100, the superabsorbent particles 200 are directed to specific areas on the die 6.

[0080] Therefore, as the first formed layer rotates out of the first hood 8a and enters the second hood 8b, the mixture of pulp fibers 11 and added superabsorbent particles 200 forms a second layer with more superabsorbent particles 200 in one area on top of the first layer to build the core of the absorbent product.

[0081] According to the prior art, as discussed, the finished cores in the mould 6 are transferred on the surface of the wheel 3 to a transfer drum 9 and finally to the conveyor belt 16 (see FIG. 2). The transfer drum 9 may be omitted. To hold the tackified fibre cores on the surface of the mat-forming wheel 3, said wheel is provided with a second suction box 5, which does not rotate inside the wheel 3, exerting a suction effect on the cores so that they adhere to the surface of the wheel. Said second suction box 5 acts along the surface of the mat-forming wheel as far as the cores are transferred on the wheel 3 from the last one of the forming chambers, the hoods 8a, 8b. In an alternative embodiment, the suction box 5 does not act along the complete second arc of the mat-forming wheel, so that the cores leave the mat-forming wheel 3 more easily without being sucked to the surface when they are delivered to the transfer drum or conveyor belt 16.

[0082] It should be appreciated that only one hood may be provided in the device, for example if the core should have only one layer of superabsorbent particles mixed with pulp fibers. When the final product may consist of several cores, the device for said final product may consist of two or more mat-forming wheels 3, each of which forms a core, whereupon two or more resulting cores are assembled into the final product. Each mat-forming wheel may have a similar design as described, for example with two hoods, a particle feed conduit in one of them and a particle redirector arranged near the opening of the particle feed conduit.

[0083] Alternatively, a mat-forming belt comprising dies can be used for the mat-forming wheel. Figure 3 shows diagrammatically the apparatus 1" with a mat-forming belt 13 with dies 6' on its outer surface. The mat-forming belt 13 may be driven by a drive motor, which can be involved in driving the belt via a gear mechanism (not shown). As in figures 1 and 2, the apparatus 1" comprises two hoods 8a' and 8b'. The forming chambers / hoods 8a', 8b' each form a passage 7'. The mat-forming belt 13 for forming the cores of the absorbent products is arranged to rotate under the downstream openings of the hoods 8a', 8b' and is sealed connected with said hoods. The mat-forming belt 13 moves in the direction indicated by the arrow 13a, which is the machine direction MD. In the embodiment according to the figure, the device comprises two hoods 8a' and 8b'. Facing each hood opening, a first non-rotating suction box 2' is arranged inside the mat-forming belt 13. Air permeable means are arranged along the circumference of the mat-forming belt 13 to allow air to pass from the suction box 2' to the inside of the mat-forming belt. Low pressure prevails in the first suction box 2' to draw air from the hood 8' through the air permeable means, generating a radially inward air flow 15'. The low pressure may be generated by means of a fan, not shown.

[0084] A second non-rotating suction box 5' is positioned inside the belt 13 and exerts a suction effect on the cores C, so that the cores C adhere to the surface of the belt until they leave the mat-forming belt 13 and are transferred to the transfer belt 16'.

[0085] The fibres 11' delivered to the hoods 8a', 8b' are advanced by a flow 15' towards the mat-forming belt 13 and deposited there against an air permeable means, which may consist of any net, a plate provided with holes, fibres or the like.

[0086] The mat-forming belt 13 may comprise a continuous die extending along the outer surface of the mat-forming belt. The figure shows an example in which a series of separate dies 6' are arranged along the outer surface of the mat-forming belt 13 forming separate cores C. A continuous die is utilized when the fibres deposited on the air permeable means are to be used to form a continuous layer, which is then cut into the appropriate size and shape to form the individual absorbent cores C of the absorbent product. Separate dies are used to directly form cores of specific shapes and dimensions to form the absorbent cores of the absorbent product. Variations of dies are known in the art and need not be discussed further here.

[0087] Similar to Fig. 2, Fig. 3 shows that in hood 8a' only pulp fibres 11' are used to form the first layer of the core C produced in mould 6'. The second hood 8b' comprises a particle supply conduit 4' having an opening through which the added particles are injected.

[0088] A particle redirector 100 similar to that in Figures 2-10 is positioned adjacent the opening of the supply conduit 4'. The similar particle redirector 100 is attached to the hood via a connecting plate. The superabsorbent particles 200' are redirected in the same manner as the particles 200 in Figures 2-10, and are further described in Figures 9a-9f. The function of the particle redirector 100 will therefore be described together with the apparatus 1' in Figures 2 and 4-10.

[0089] FIG. 5 shows the cross section AA in FIG. 2 and FIG. 4, but with the particle redirector 100 seen from the side. The particle redirector 100 is attached to the hood 8b via a connecting plate 300. See also FIG. 4 and FIG. 6. The hood 8b forms a passage 7, which directs the superabsorbent particles towards one of the moulds 6. The particle redirector 100 is pivotable about a pivot axis PA, which extends along a cross section CD, which is perpendicular to the machine direction MD of the movable mat-forming device 3, such that the particle redirector 100 can be pivotally moved along and against the machine direction MD to redirect the superabsorbent particles 200 to different areas on the at least one mould 6. See also FIG. 7. FIG. 7 shows the cross section BB in FIG. 5. This is done by different surfaces on the particle redirector 100. FIG. 8a-8d show the particle redirector 100 in more detail.

[0090] The particle redirector 100 is pivotable about a pivot axis PA by a motor 10 via a shaft 108 (see Figures 2, 5 and 6) that is connected to the particle redirector 100 and extends through the particle redirector 100. The motor may be an AC servo motor. Figure 6 shows a perspective view of the particle redirector 100 without a hood and connected to the motor 10 via the shaft 108 and a connecting plate 300.

[0091] The motor 10 can be operated by a programmable position control system, for example in a computer. The motor is therefore programmable so that the particle redirector 100 can assume different starting positions so that the superabsorbent particles are distributed in a specific area of ​​the mould 6. This may be the same area for all of the moulds 6 or may be different for each mould 6. The AC servo motor can be set, for example, such that said particle redirector 100 has a number of different reorientation positions, for example 18 freely programmable positions, i.e. starting positions. However, the motor and position control system are not limited thereto. The motor may be freely programmed so that the particle redirector 100 can be positioned in any position about a pivot, i.e. at any angle to the central axis CA of the feed conduit 4.

[0092] Figures 8a and 8b show the particle redirector 100 in perspective from two different orientations: Figure 8a shows the particle redirector 100 in a first orientation, and Figure 8b shows the particle redirector 100 in a second orientation, where the particle redirector 100 has been pivoted 180 degrees about pivot axis PA.

[0093] Particle redirector 100 includes a base 101 having a convex surface 102 and an opposing concave surface 103, and a periphery 104. Base 101 is generally oval in shape and has a predetermined thickness. Base 101 may alternatively have a round shape or any other shape suitable for the present application.

[0094] A first imaginary plane P1 is aligned along pivot axis PA and bisects the base 101 into two equal halves such that a cross-section of the base 101 at the first imaginary plane P1 is U- or V-shaped. Base 101 is illustratively U-shaped and can be seen in Figure 8d, which is a view of particle redirector 100 viewed normal to first imaginary plane P1.

[0095] A second imaginary plane P2 is disposed perpendicular to the first imaginary plane P1. The first imaginary plane P1 and the second imaginary plane P2 intersect along the pivot axis PA.

[0096] A third imaginary plane P3 bisects the base 101 into two equal halves. The third imaginary plane P3 is perpendicular to the first imaginary plane P1 and the second imaginary plane P2. The third imaginary plane P3 intersects the first imaginary plane P1 along a first axis A1. The third imaginary plane P3 also intersects the imaginary plane P2 along a second axis A2.

[0097] The concave surface 103 and the convex surface 102 of the base 101 in a cross section taken along the third imaginary plane P3 are essentially straight and parallel to the second axis. This can be seen in Figure 8C, which shows a cross section taken along the third imaginary plane P3.

[0098] The particle redirector 100 further comprises at least two flanges, a first flange 105a and a second flange 105b, extending from the convex surface 102 on either side of the first imaginary plane P1 and essentially parallel to the first imaginary plane P1. The concave surface 103 or the convex surface 102, together with the flanges 105a, 105b, direct the superabsorbent particles 200 into the mold 6 when the mold 6 is mounted in the apparatus 1', 1". The two flanges 105a, 105b are disposed at the same predetermined distance from the first imaginary plane P1. A third flange 106 extends from the convex surface 102 aligned with the first imaginary plane P1 and is parallel to the first imaginary plane P1.

[0099] A fourth flange 108 extends from the convex surface 102 aligned with and parallel to the third imaginary plane P3. The fourth flange 108 extends between the first flange 105a and the third flange 106, and between the third flange 106 and the second flange 105b. This fourth flange adds mechanical stiffness, preferably lower than the first, second and third flanges 105a, 105b, 106.

[0100] Each of the first flange 105a, the second flange 105b, and the third flange 106 extending from the convex surface 102 has a predetermined height. The predetermined height is highest at the point of intersection with the third imaginary plane P3. Each flange also has a predetermined thickness. The thickness can be selected so that the flange particle redirector is sufficiently strong. All three flanges 105a, 105b, 106 extend from a periphery 104 on one side of the third imaginary plane P3 to a periphery 104 on the opposite side. However, the flanges 105a, 105b, 106 may extend a fixed distance from the periphery 104.

[0101] Figure 8c shows a cross section of the particle redirector 100 taken from a third imaginary plane P3. The pivot axis PA is located at the centre of gravity CG (see also Figure 8a) of the particle redirector 100. The pivot axis PA is located at substantially equal predetermined distances D from the highest points H1, H2, H3 of each flange 105a, 105b, 106. The pivot axis PA is also located at substantially the same equal predetermined distances D from outer points OP1, OP2 of the periphery 104 of each side of the imaginary plane P1 in the cross section taken along the third imaginary plane. Therefore, in the cross-section shown in Figure 8c, i.e. a cross-section taken along imaginary plane P3, a partial circle can be drawn from a first outer point OP1 of the peripheral portion through the highest points H1, H2, H3 of each flange 105a, 105b, 106 to a second outer point PO2 of the peripheral portion 104 on the opposite side of the first imaginary plane P1 (not shown), in which case the midpoint of the partial circle coincides with the centre of gravity CG and the radius of the partial circle is a predetermined distance D.

[0102] The first and second flanges 105a, 105b are arranged at a distance D1 from each other, the distance D1 being essentially equal to the inner diameter DO of the opening 4a of the particle supply conduit 4, 4' (see FIG. 7), but the distance may be smaller or larger than the inner diameter of the opening.

[0103] The maximum width W1 of the particle redirector 100 in a cross section taken along the third imaginary plane P3 (see Figures 8c and 7) may be greater than or equal to the diameter opening DO of the particle supply conduit 4, such that essentially all particles impact the base. In Figure 7, the maximum width W1 is shown to be greater than the diameter opening DO of the particle supply conduit 4.

[0104] 8d shows the particle redirector 100 as viewed normal to a first imaginary plane P1. The maximum width W2 of the base 101 of the particle redirector 100 is larger than the diameter opening of the particle supply conduit 4 such that essentially all particles impinge on the particle redirector.

[0105] The maximum width W3 of the particle redirector 100 is greater than the maximum width W2 of the base 101. The maximum widths of the base and the particle redirector are in a cross section taken along a first imaginary plane P1.

[0106] Each of the flanges 105a, 105b, 106 has a curved external shape, as seen in Fig. 8d, which curves downwards from its highest point H1, H2, H3 to the periphery 104 on either side of a third imaginary plane P3, i.e. on either side of axis A1, i.e. each of the first, second and / or third flanges has a curved external shape starting from said highest point towards said convex base 102, as viewed normal to said first imaginary plane P1.

[0107] The external contour of the third flange 106 is symmetrical on both sides of the axis A1, curving from its highest point H2 to a point PF1 at the maximum width W3 of the particle redirector, and from that point PF1 towards the outer edge 104 of the base. The first and second flanges 105a, 105b have matching curvatures. The curvatures are such that the base 101 and the first, second and third flanges 105a, 105b, 106 extending from the convex surface 102 of the particle redirector 100 on the convex side 102 of the base 101, are the overall shape of a portion of an imaginary ellipsoid E (see FIG. 8b). That is, the external contours of the first, second and third flanges 105a, 105b, 106b together with the base 101 follow the shape of the imaginary surface of the partial imaginary ellipsoid E.

[0108] As shown in Figures 5 and 7, a particle redirector 100 is positioned near the opening 4a of the particle supply conduit 4. Figure 10 shows an enlarged perspective view of the particle redirector 100 and particle supply conduit 4 of Figures 5 and 7. A first axis A1 of the superabsorbent particle redirector 100 is aligned with a central axis CA of the particle supply conduit 4.

[0109] The second flange 105a, 105b is aligned with the wall of the particle supply conduit 4, and the third flange 106 extends into the opening 4a of the particle supply conduit 4. The end of the particle supply conduit 4, i.e. at the opening 4a, is fitted to the particle redirector 100. The end may be designed such that when a part of the flange of the particle redirector 100 protrudes into the opening of the particle supply conduit 4, the particle redirector 100 can pivot, i.e. rotate, without colliding with the particle supply conduit 4. For example, the end of the particle supply conduit 4 may have a shape that matches the outer contour of the first, second and third flanges 105a, 105b, 106b, which together with the base 101 follow the shape of the imaginary surface of the partial imaginary ellipsoid. That is, the end of the particle supply conduit 4 may have a shape that corresponds to the imaginary surface of the partial imaginary ellipsoid. As can be seen in Fig. 5 and especially in Fig. 10, the end of the particle supply conduit 4 has a concave shape when viewed normal to the first imaginary plane P1 of the particle orienting device and a convex shape when viewed normal to the third imaginary plane P3 of the particle orienting device (see Fig. 8a for a plan view). The end of the particle supply conduit 4 forming the opening therefore has as a concave / convex extension around the circumference of the particle supply conduit 4. Preferably, the particle orienting device 100 is arranged such that there is a minimum space, i.e. distance D2, between the first flange 105a and the end of the particle supply conduit 4 when the flange is parallel to the central axis CA of the particle supply conduit 4 and facing the opening 4a. The same applies to the second flange 105b and the third flange 106. Due to the first, second and third flanges 105a, 105b, 106 and the distance D2 from the pivot axis PA to the end points PO1 and PO2 being the same, and the shape of the flanges following the shape of the imaginary surface of a partial imaginary ellipsoid, the particle orienting device 100 does not collide with the particle supply conduit 4 during pivoting. The space between the flanges and the end of the particle supply conduit 4 is preferably minimized to reduce uncontrolled airflow entering in unwanted directions. The distance may be 1-4 mm, more preferably 2 mm.

[0110] 8a-8d. If the particle supply conduit 4 has an internal diameter DO of 46 mm with walls of 2 mm, for example, a particle orienting device 100 made from stainless steel may have the following dimensions:

[0111] The oval base is 2 mm thick and curved with a radius R (see FIG. 8d) on the concave side forming a curved portion. The radius is 18 mm. On each side of the axis A1, the base transitions from the curved portion to a flat portion 109. The angle α between the flat portions 109 is 60 degrees. The base is not limited to having a flat portion, but may also be a single curved portion.

[0112] The maximum width W2 of the base is 49 mm. W3 is 60 mm. The predetermined distance D between the pivot PA and the highest point H1, H2, H3 of each flange 105a, 105b, 106 and between the pivot PA and each outer point OP1, OP2 of the peripheral portion 104 is 45 mm. Therefore, if a curvature is drawn between the outer points OP1, OP2 and the highest point H1, H2, H3 of each flange 105a, 105b, 106, a partial circle can be drawn. The partial circle then has a radius of 45 mm. The central axis of the circle is aligned with the pivot PA.

[0113] The maximum width W1 of the base 101 in a cross section taken along the plane P3 is about 90 mm.

[0114] Each of the flanges 105a, 105b, 106 has a thickness of 1 mm. The external shape of the third flange 106 when viewed in the normal direction of the first imaginary plane P1 is curved symmetrically on both sides of the axis A1 from its highest point H2 to a point PF1 at the maximum width W3 of the particle orienter, and from that point PF1 to the outer edge of the base.

[0115] The outer contours of the first and second flanges 105a, 105b follow at a fixed distance the outer contour of the third flange 106. The distance should be selected such that the particle orienting device obtains the overall shape of the partial imaginary ellipsoid E.

[0116] In this example, the opening of the particle supply conduit 4 is located at a certain distance from the moving mat-forming device. The distance is here 150 cm, so that the fibrous material and the particles can mix before arriving at the mould. The particle redirector 100 protrudes into the particle supply conduit 4, so that the particles are mixed with the fibrous material before arriving at the mould.

[0117] 5, 7 and 10 show the particle redirector 100 extending partially into the particle supply conduit 4, the particle redirector 100 is not limited to this and can be positioned at a distance from the opening. The distance should be selected such that nearly all particles from the particle supply conduit 4 impinge on the particle redirector 100.

[0118] Particle redirector 200 further comprises a shaft connection element 107 (see Figures 8a and 8b) extending along said pivot axis PA adapted to receive a shaft 108 connectable to said shaft connection element 107 for pivoting said particle redirector about said pivot axis PA (see Figures 5 and 6). Shaft connection element 100 is illustrated here as having a cylindrical shape in particle redirector 100 with an opening through which the shaft extends and with which it is connected.

[0119] Particle redirector 200 is made from stainless steel, but any other material that is strong and wear resistant can be used.

[0120] The shape of the flanges 105a, 105b, 106 and the elliptical base 101 of the particle redirector 100 is described such that together they form the overall shape of a part of an imaginary ellipsoid E (see FIG. 8b). That is to say, the outer contours of the first, second and third flanges 105a, 105b, 106b together with the base 101 follow the shape of the imaginary surface of the partial imaginary ellipsoid E. However, the particle redirector is not limited to this. The first, second and third flanges 105a, 105b, 106b may have another curved shape when viewed in the normal direction of the first imaginary surface P1. They may also be rectangular in shape. The end of the particle supply conduit 4 is then adapted to the shape of the particle redirector.

[0121] Figures 9a-9f show the apparatus 1' of Figure 4 with the pivotable particle redirector 100 shown and described in Figures 8a-8d in different starting positions inside the hood 8b. Based on the starting position of the particle redirector 100 in relation to the outlet 4a of the particle supply conduit 4, the pivoting direction and the pivoting speed of the particle redirector 100, the superabsorbent particles 200 can be distributed in at least one region on the mould 6. That is to say, the particle redirector 100 comprises a redirecting surface adapted to redirect the superabsorbent particles 200 in the machine direction MD and / or the cross direction CD in the machine direction MD depending on the position of the particle redirector 100 inside the passage 7. The redirecting surface of the particle redirector 100 is a first, second, third and fourth flange 105a, 105b, 106, 108 or a convex surface 102 together with a concave surface 103.

[0122] The apparatus 1' of Figures 9a-9f is the same apparatus as shown in Figures 4-7, which redirects the superabsorbent particles 200 towards one mould 6 on a moving mat-forming device 3 moving in the machine direction MD. In the mould 6, an absorbent core is formed. The absorbent core comprises a front portion, a rear portion and a bifurcation portion located between the front portion and the rear portion. The core has a longitudinal axis extending along the length of said core and intersecting said front portion, bifurcation portion and rear portion, and the absorbent core has a width extending perpendicular to said length and a perimeter including at least two opposing ends and at least two opposing side portions located between said ends. The shape of the mould 6 forms the outer contour of the core, and the longitudinal axis AC of the mould extends in the machine direction MD, so that the leading portion 6a of the mould 6 may be the portion that forms the front portion of the absorbent core, the trailing portion 6b may form the rear portion of the absorbent core, and the intermediate portion 6c between the leading portion 6a and the trailing portion 6b forms the bifurcation portion (see Figures 9a"-9f"). In the following example, the leading part 6a of the mould forms the front part of the core and the trailing part 6b forms the rear part of the core, although this may be reversed.

[0123] In Figures 9a-9f, the particle redirector 100 is positioned a shorter distance from the opening 4a of the particle supply conduit 4 than the particle redirector 100 of Figures 4-7, but as long as a majority of the highly absorbent particles impinge on the particle redirector, it will function in a similar manner when positioned as described in Figures 4-7.

[0124] Reorientation of the superabsorbent particles 200 is effected in a particle redirector 100 located adjacent the opening 4a, said particle redirector 100 being pivotable about a pivot axis PA extending in a cross direction CD relative to the machine direction MD of the movable mat forming device 3. Figures 9a'-9f' are enlargements of each of the particle redirectors 100 of Figures 9a-9f, but shown slightly in perspective, and for illustrative purposes arrow A symbolizes the direction in which the superabsorbent particles 200 impact the particle redirector 100 and the direction which they follow after impacting the particle redirector 100.

[0125] In order to distribute the superabsorbent particles 200 to specific areas, the particle redirector 100 needs to pivot during the process. If the particle redirector 100 is stationary, the superabsorbent particles 200 should be distributed evenly over the entire length of the absorbent core. Therefore, the apparatus 1' pivots the particle redirector 100 about the pivot axis PA along and / or against the machine direction MD during production, thereby directing the superabsorbent particles 200 to different areas on the at least one mould 6.

[0126] In Figure 9a, the particle redirector 100 is positioned in a starting position with the concave surface 103 facing the particle supply conduit opening 4a in a slightly inclined position, so that the highly absorbent particles 200 are directed by the concave surface 103 towards the leading edge 106a of the mould 6 as they enter the hood 8b. So as the highly absorbent particles leave the particle supply conduit 4 (arrow A in Figure 9a'), they impact the concave surface 103 and slide down the concave surface towards the outer edge OP1 before falling down towards the mould 6. In a first step, the particle redirector 100 is pivoted in a first direction, arrow B, at a first speed at the same time that the highly absorbent particles enter the passage 7 and impact the particle redirector 100. The first speed should cause the highly absorbent particles close to the mold 6 to travel at the same speed and in the same direction as the mat-forming device 3, i.e. in the machine direction MD, so that the highly absorbent particles 200 are directed at the front part 6a of the mold 6 along the center line AC of the mold extending in the machine direction MD. This result can be seen in FIG. 9a″. Due to the pivoting of the particle redirector, the highly absorbent particles 200 are concentrated in some areas of the mold 6 more than in other areas. Hence, the absorbent core in this case has more highly absorbent particles 200 at the front part 6a along its center line AC, although it should be recognized that some particles may also fall into other areas.

[0127] The opening 4a of the particle supply conduit 4 is positioned at a distance from the movable mat-forming device 3 so that the fibrous material 11 and the superabsorbent particles 200 can mix before reaching the mold. In the area with the superabsorbent particles 200 in the mold 6 shown in Figure 9a'', the particles are mixed with the fibrous material 11. The area around the superabsorbent particles 200 in the mold also comprises fibrous material (not shown) as fibrous material 11 is added continuously throughout the process.

[0128] In a second step, the particle redirector 100 pivots back to its starting position in the opposite direction to the first direction at a second, faster speed. The advantage of doing this is that once the superabsorbent particles have been distributed in a particular area, the particle redirector 100 pivots back to its starting position so that, for example, once the first mold 6 has received superabsorbent particles in its predefined area, the particle redirector is ready to distribute the superabsorbent particles to the same predefined area on the next mold 6. If there is only one mold that creates one long core that is later separated into separate cores, the same thing will happen, certain areas will have more superabsorbent particles than others. Alternatively, instead of pivoting back, i.e., pivoting in the opposite direction to the first direction, the particle redirector can continue pivoting back to its starting position in the same first direction at a second, faster speed.

[0129] The apparatus of Figures 9b-9f function in the same manner, but the starting position of the particle redirector 100 is different in order to distribute the superabsorbent particles to different areas of the mold. Only the starting position is described for Figures 9b-9f, and how the superabsorbent particles 200 are distributed in the mold 6 as a result of the starting position. The pivoting of the particle redirector 200, i.e., the speed and direction of both the first and second steps, is the same as described for Figure 9a. The rotation of the mat-forming wheel, i.e., the direction and speed, is the same as described for Figure 9a. However, it should be understood that the pivoting direction can also be opposite to the machine direction, depending on how the particle redirector is positioned in its starting position and where the particles are desired to be in the mold. For example, for Figure 9a, if the pivoting direction of the first step was opposite to the machine direction, more particles would be along the centerline AC. It should be appreciated that the particle redirector 100 can be programmed to move at different speeds and in different directions so that the particles can be distributed as desired in the mold. It should also be appreciated that the starting position may vary from mold to mold, such that a core formed in one mold may be different from a core formed in another mold, for example a mold adjacent to the first mold.

[0130] In FIG. 9b, the particle redirector 100 is positioned such that more highly absorbent particles 200 are distributed towards the leading edge 6a of the die 6 entering the hood 8b, but also in the cross direction CD of the machine, so that the entire width of the die 6 in that area can pick up highly absorbent particles (see FIG. 9b″). This gives more highly absorbent particles 200 in front of the core, but across the entire width of the core. This is because the highly absorbent particles 200 are directed by the flange and convex surface 102 (arrows in FIG. 9b′). This is achieved by having the particle redirector at its starting position, angled to opening 4a, with flanges 105a, 105b, 106 slightly angled to opening 4a of the particle supply conduit, as shown in FIG. 1A. The highly absorbent particles 200 are directed towards the leading edge 6a, across the entire width of the core at that position, by first flange 105a, third flange 106 in particular, and also by fourth flange 108, as the particles also slide over the convex surfaces 102 on either side of fourth flange 108.

[0131] In FIG. 9c, the particle redirector 100 is positioned such that more highly absorbent particles 200 are distributed towards the more intermediate portion 6c between the leading portion 6a and the trailing portion 6b of the die 6, but also in the more cross direction CD of the machine, so that the entire width of the die 6 in that region can acquire highly absorbent particles 200 (see FIG. 9c"). This provides more highly absorbent particles 200 at the branching portion of the core, but also across the entire width of the core. This is achieved by having the flanges of the particle redirector 100, in its starting position, facing the opening 4a of the particle supply conduit, such that the highly absorbent particles 200 are directed towards the intermediate portion 6c by the flanges 105a, 105b as well as the convex surface 102, and also by the fourth flange 108 (see arrow A in FIG. 9c'). The highly absorbent particles hit the particle redirector 100 on both sides of the fourth wall 108, and therefore the particles 200 are directed across the entire width of the die 6.

[0132] In FIG. 9d, the particle orienting device 100 is positioned such that more highly absorbent particles 200 are distributed towards the more rearward part 6b of the die 6, but also in the more transverse direction CD of the machine, so that the entire width of the die 6 in that region can acquire highly absorbent particles (see also FIG. 9d″). This provides more highly absorbent particles 200 at the rear part of the core, but also across the entire width of the core. This allows the highly absorbent particles 200 to be concentrated on the flanges and convex surface 102, and in particular on the second flange 105b and the third flange 106, as well as on the convex surface 102. This is achieved by having the particle redirector 100 in its starting position angled to the opening 4a of the particle supply conduit 4, with the flange in a slightly angled position to the opening 4a of the particle supply conduit, but facing in the opposite direction in Figure 9b, so that the particles 200 are directed towards the rear part 6b by the fourth flange 108 (see arrow A in Figure 9d'). The highly absorbent particles 200 also impinge on the convex surfaces 102 of the particle directing device 100 on either side of the fourth wall 108 and therefore the particles 200 are directed across the full width of the mould 6.

[0133] In Figure 9e, the particle redirector 100 is positioned so that more of the highly absorbent particles 200 are distributed along the centre line AC (see Figure 9e") towards the more rearward portion 6b of the mould 6. This is achieved by having a concave surface 103 at a slightly inclined position at the particle supply conduit opening 4a, but facing in the opposite direction to Figure 9a. By having this starting position, the highly absorbent particles 200 are directed by the concave surface 103 towards the more rearward portion 6b of the mould 6 (see arrow A in Figure 9e').

[0134] In Figure 9f, the particle redirector 100 is positioned such that more highly absorbent particles 200 are distributed along the centerline AC of the die 6 (see also Figure 9f") towards both the leading and trailing portions 6a, 6b. This provides more highly absorbent particles 200 along the centerline AC to both the front and rear portions of the core. This is achieved by having the concave surface 103 of the particle redirector 100 in a starting position facing the opening 4a of the particle supply conduit 4, such that when the highly absorbent particles collide with the concave surface 103, they can be directed in either direction and fall over the outer circumferential edge 104 towards the die 6, since the highly absorbent particles 200 are directed in two directions by the concave surface 103 (see arrows A in Figure 9f').

[0135] The different starting positions of the particle redirector 100 are not limited to those described in Figures 9a-9f. The starting position may be any position in between. The position may be set and adjusted by a computer program operating the motor. The position of the superabsorbent particles within the mold may be manipulated by the starting position of the particle redirector relative to the mold, the position of the flange of the particle redirector relative to the base and / or the opening of the particle feed conduit, the speed and / or direction of pivoting of the particle redirector.

[0136] The particles described for the flanges are described as being highly absorbent particles, however, it should be recognized that other particles, such as heat activated adhesive particles or odor absorbing particles, may also be distributed in a similar manner.

[0137] Figures 11a-11b show a particle redirector 100' similar to Figures 8a-8d with similar features, except for the base 101, which has a slightly different shape. Only the differences will be described. The base 101 still has a convex surface 102 and a concave surface 103, as well as a periphery 104, but the base has a "saddle shape". The general three-dimensional shape of the base 101 can be described as a shape defined by the surface of a hyperbolic parabola with a planar ellipse superimposed thereon.

[0138] The present disclosure also covers all possible combinations of the described aspects, variations, alternatives and exemplary embodiments of the present disclosure.

[0139] Furthermore, the present disclosure is not limited to the above aspects or examples, but can certainly be applied to other aspects and exemplary embodiments within the scope of the following claims.

[0140] The reference signs in the claims should not be construed as limiting the extent of the matter protected by the claims, but their only function is to make the claims easier to understand. [Explanation of symbols]

[0141] 1 device 2. First Suction Box 3 Mat forming wheel (mat forming device) 4 Supply conduit 5. Second Suction Box 6. First Mold 7 Passage 8. Food 9 Transfer drum 10 Motor 11 Fibrous materials 13 Belt 16 Conveyor 100 Highly absorbent particle redirector 101 Base 102 Convex surface (convex base, convex side) 103 Concave surface 104 Outer edge (peripheral edge) 106 Third flange 107 Shaft connecting element 108 Fourth Flange 109 Flat area 200 Particle Reorienter 300 Connection Plate

Claims

1. An apparatus (1', 1") for manufacturing an absorbent core (C) for an absorbent product, said absorbent core (C) comprising a fibrous material (11, 11') and particles (200, 200') distributed through at least a portion of said fibrous material (11, 11'), said apparatus (1', 1") comprising: The device (1', 1") a movable mat-forming device (3, 13) comprising at least one mould (6, 6'), said movable mat-forming device (3, 13) being movable in a machine direction (MD); a passage (7, 7') for directing said mixture of said fibrous material (11, 11') and said particles (200, 200') towards said at least one mould (6, 6') in order to deposit at least one layer of said mixture of said fibrous material (11, 11') and said particles (200, 200') in said at least one mould (6, 6'); a particle supply conduit (4, 4') having an opening (4a) inside said passage (7, 7'); Including, The apparatus (1', 11) further comprises a particle redirector (100) disposed adjacent to the opening (4a) of the particle supply conduit (4, 4a'), the particle redirector (100, 100') being pivotable about a pivot axis (PA) extending in the machine direction (MD) or opposite to the machine direction (MD) in a cross direction (CD) to the machine direction (MD), thereby redirecting the particles (200, 200') to at least one region on the at least one mold (6, 6').

2. The particle redirector (100, 100') includes a base (101) having a convex surface (102) and an opposing concave surface (103) and a periphery (104); a first imaginary plane (P1) is aligned along said pivot axis (PA) and bisects said base (101) into two halves such that a cross section of said base (101) taken along said first imaginary plane (P1) is U- or V-shaped; a second imaginary plane (P2) is perpendicular to the first imaginary plane (P1), and the first imaginary plane (P1) and the second imaginary plane (P2) intersect along the pivot axis PA; a third imaginary plane (P3) bisects the base (101) into two halves, the third imaginary plane (P3) being perpendicular to the first imaginary plane (P1) and the second imaginary plane (P2), the third imaginary plane (P3) intersects the first imaginary plane (P1) along a first axis (A1) and intersects the second imaginary plane (P2) along a second axis (A2); the particle redirector (100, 100') includes at least a first flange (105a) and a second flange (105b) extending from the convex surface (102) on each side of the first imaginary plane (P1) and essentially parallel to the first imaginary plane (P1), the concave plane (103) or the convex surface (102) together with the flanges (105a) and (105b) direct the particles (200, 200') towards the mould (6, 6'); The device (1, 1') according to claim 1, wherein the pivot axis (PA) is located at a center of gravity (CG) of the particle redirector (100, 100') or at a fixed distance from the center of gravity (CG) along the first imaginary plane (P1).

3. 3. The device (1, 1') according to claim 2, wherein the first imaginary plane (P1) bisects the base (101) into two equal halves and the third imaginary plane (P3) bisects the base into two equal halves.

4. The device (1, 1') according to any one of claims 1 to 3, wherein said particles (200, 200') are high-absorbency particles, heat-activated adhesive particles or odor absorbing particles.

5. The apparatus (1, 1') according to any one of claims 2 to 4, wherein a third flange (106) extends from the convex surface (102) aligned with the first imaginary plane (P1) and is parallel to the first imaginary plane (P1).

6. The apparatus (1, 1') according to any one of claims 2 to 5, wherein a fourth flange (108) extends from the convex surface (102) aligned with the third imaginary plane (P3) between the first flange and the second flange (105a, 105b) and is parallel to the third imaginary plane (P3).

7. The device (1, 1') according to any one of claims 2 to 6, wherein the pivot axis (PA) in a cross section taken along the third imaginary plane (P3) is located at a substantially equal predetermined distance (D) from a highest point (H1, H2, H3) of each of the first, second and / or third flanges (105a, 105b, 106) and from an outer point (PO1, PO2) of the periphery (104) on each side of the first imaginary plane (P1).

8. The device (1, 1') according to any one of claims 2 to 7, wherein each of the first, second and / or third flanges (105a, 105b, 106) has a curved outer shape extending from a highest point (H1, H2, H3) of the respective flange (105a, 105b, 106) towards the convex surface (102), as viewed normal to the first imaginary plane (P1).

9. The particle redirector (100, 100') has an outer contour formed by the first, second and / or third flanges (105a, 105b, 106) together with the base (101) which in part follows the shape of an imaginary surface of an imaginary ellipsoid (E).

10. The apparatus (1,1') according to any one of claims 2 to 9, wherein at least a part of the particle redirector (100,100') protrudes into the opening (4a) of the particle supply conduit (4,4') or the particle redirector (100,100') is arranged in close proximity to the opening (4a) of the particle supply conduit (4,4').

11. The apparatus (1,1') according to any one of claims 2 to 10, wherein the opening (4a) of the particle supply conduit (4,4') has a shape and / or diameter such that the outer contour of the particle redirector (100,100') is free to pivot adjacent to the particle supply conduit (4,4') or at least partially inside the particle supply conduit (4,4').

12. The apparatus (1, 1') according to any one of claims 2 to 11, wherein the first and second flanges (105a, 105b) are arranged at a distance (D1) from each other, which is equal to, smaller than or larger than an inner diameter opening (DO) of the particle supply conduit (4, 4').

13. The apparatus (1,1') according to any one of claims 2 to 12, wherein a maximum width (W2) of the base (101) of the particle redirector (100, 100') in a cross section taken along the first imaginary plane (P1) is equal to or greater than the inner diameter (DO) of the particle supply conduit (4, 4').

14. Apparatus (1,1') according to any one of claims 2 to 13, wherein the first axis (A1) of the particle redirector (100) is aligned with a central axis (CA) of the particle supply conduit (4,4').

15. The particle redirector (100, 100') comprises a shaft connecting element (107) extending along the pivot axis (PA) adapted to accommodate a shaft (8) connectable to the shaft connecting element (107) for pivoting the particle redirector (100) about the pivot axis (PA).

16. The apparatus (1,1') according to any one of claims 1 to 15, wherein the particle redirector (100,100') is pivotable about the pivot axis (PA) by means of a shaft (108) connected to the particle redirector (100) which is rotatably supported in the passage (7,7').

17. Apparatus (1,1') according to any one of the preceding claims, wherein said particle redirector (100,100') is pivotable about said pivot axis (PA) by means of a motor (10).

18. A particle redirector (100, 100') comprising a base (101) having a convex surface (102) and an opposing concave surface (103) and a periphery (104), a first imaginary plane (P1) is aligned along said pivot axis (PA) and bisects said base (101) into two halves such that a cross-section of said base (101) in said first imaginary plane (P1) is U- or V-shaped; a second imaginary plane (P2) is perpendicular to the first imaginary plane (P1), and the first imaginary plane (P1) and the second imaginary plane (P2) intersect along the pivot axis (PA); a third imaginary plane (P3) bisects the base (101) into two halves, the third imaginary plane (P3) being perpendicular to the first imaginary plane (P1) and the second imaginary plane (P2), the third imaginary plane intersects the first imaginary plane (P1) along a first axis (A1) and intersects the second imaginary plane (P2) along a second axis (A2); the particle redirector (100, 100') includes at least a first flange (105a) and a second flange (105b) extending from the convex surface (102) on each side of the first imaginary plane (P1) and essentially parallel to the first imaginary plane (P1); The particle redirector (100, 100'), wherein said pivot axis (PA) is located at the centre of gravity (CG) of said particle redirector (100, 100') or at a fixed distance from said centre of gravity (CG) along said first imaginary plane (P1).

19. 19. The particle redirection device (100, 100') of claim 18, wherein the first imaginary plane (P1) bisects the base (101) into two equal halves and the third imaginary plane (P3) bisects the base (101) into two equal halves.

20. 20. A particle redirector (100, 100') according to claim 18 or 19, wherein a third flange (106) extends from the convex surface (102) aligned with the first imaginary plane (P1) and is parallel to the first imaginary plane (P1).

21. A particle redirector (100, 100') according to any one of claims 18 to 20, wherein a fourth flange (108) extends from the convex surface (102) aligned with the third imaginary plane (P3) between the first flange and the second flange (105a, 105b) and is parallel to the third imaginary plane (P3).

22. A particle redirection device (100, 100') according to any one of claims 18 to 21, wherein the pivot axis (PA) in a cross section taken along the third imaginary plane (P3) is located at a substantially equal predetermined distance (D) from a highest point (H1, H2, H3) of each of the first, second and / or third flanges (105a, 105b, 106) and from an outer point (OP1, OP2) of the periphery (105) on each side of the first imaginary plane (P1).

23. A particle redirection device (100, 100') as claimed in any one of claims 18 to 22, wherein each of the first, second and / or third flanges (105a, 105b, 105c) has a curved outer shape extending from a highest point (H1, H2, W3) of the respective flange (105a, 105b, 105c) towards the convex surface (102), as viewed normal to the first imaginary plane (P1).

24. The particle redirector (100) of any one of claims 18 to 23, wherein the particle redirector (100) has an outer contour formed by the first, second and / or third flanges (105a, 105b, 106) together with the base (101) which in part follows the shape of an imaginary surface of an imaginary ellipsoid (E).

25. A particle redirector (100, 100') according to any one of claims 18 to 24, wherein the first and second flanges (105a, 105b) are positioned at a fixed distance from each other.

26. A particle redirector (100, 100') as claimed in any one of claims 18 to 25, wherein the base (101) of the particle redirector (100) has a maximum width (W2) in a cross section taken along the first imaginary plane (P1).

27. The particle redirector (100) of any one of claims 18 to 26, comprising a shaft connection element (107) extending along the pivot axis (PA) adapted to accommodate a shaft (108) connectable to the shaft connection element (107) for pivoting the particle redirector about the pivot axis (PA).

28. A method for redirecting particles (100, 100') fed from an opening (4a) of a particle feed conduit (4, 4') inside a passage (7, 7') directing said particles (200, 200') towards at least one die (6, 6') on a moveable mat-forming device (3, 13) moving in a machine direction (MD), said redirection being performed in a particle redirector (100) arranged adjacent to said opening (4a), said particle redirector (100) comprising: The particle redirector (100, 100') is pivotable about a pivot axis (PA) extending in a transverse direction (CD) to the machine direction (MD) of the movable mat forming device (3, 13), the method comprising the step of pivoting the particle redirector (100, 100') about the pivot axis (PA) along and / or against the machine direction (MD), thereby redirecting the particles (200, 200') to at least one region on the at least one mold (6, 6').

29. The method of claim 28, wherein the particle redirector (100, 100') is a particle redirector according to any one of claims 18 to 27.

30. 30. The method according to any one of claims 28 or 29, wherein in a first step the particle redirector (100, 100') is pivoted from a start position in the same direction as the mat forming device (3, 13) or in an opposite direction to the mat forming device (3, 13) at a first speed such that particles (200, 200') are directed to a particular area on the mould (6, 6').

31. 31. The method of claim 30, wherein in a second step, the particle redirector (100, 100') pivots in a direction opposite to the first direction at a second speed that is faster than the first speed.

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