METHOD AND DEVICE FOR DOSING AND APPLYING A SMALL QUANTITY OF PARTICULAR MATERIAL

Description

[0001] The present invention relates to a method for dosing and applying a small quantity of a particulate material in a high-speed manufacturing machine for absorbent hygiene products, wherein components of the hygiene products to be manufactured are successively fed and conveyed in the manufacturing machine as the target structure for the particulate material to be applied, wherein a metering roller with cavities provided in its outer circumferential surface for receiving the particulate material is used, wherein the successively fed components are guided past and preferably below the metering roller and preferably at a distance from the metering roller.

[0002] Methods and devices for metering and applying superabsorbent particles using continuously driven metering rollers are known, for example, from EP0347544, WO 13 / 0084311 A1, EP 1 655 007 A1, and EP 2 583 648 A1. In these methods, considerable quantities of superabsorbent granules are introduced between flat materials to form a SAP laminate. In another method according to EP 2 777 664 B1, a superabsorbent particle material is placed in a container, and an outlet opening from the container is alternately opened and closed by means of a pivotable wedge-shaped element, so that a uniform and predetermined quantity of material can trickle out and reach a conveyor belt or a target structure conveyed thereon.

[0003] When superabsorbent particulate material is applied to components of hygiene products, this typically involves relatively substantial quantities of at least 5.0 g, in particular at least 8.0 g, and especially at least 10.0 g of particulate material. In contrast, the present invention relates to a method for dosing and applying a smaller quantity of, for example, at most 2.0 g or at most 1.0 g of particulate material. This material may, for example, be a pH regulator, in particular an acid or its salts or a mixture thereof, in particular monosodium citrate or disodium citrate, which is to be supplied to and applied to a rather narrowly defined area of ​​an absorbent component.

[0004] Typically known devices and methods for dosing and applying larger quantities of superabsorbent material per article are not suitable for precisely applying very small quantities of a potentially unfree-flowing, i.e., fine-grained or powdered, particulate material in a predetermined small amount. With these known devices and methods, particulate material is either dispensed more or less continuously, or only broad Gaussian distributions of particle quantities can be applied, resulting in a non-constant application quantity and an unsatisfactory distribution or application of the material on the target structure.

[0005] When metering rollers are used, they are operated at a constant speed and usually roll opposite the component being fed. Their cavities are either evenly distributed around the outer circumference of the roller or arranged in groups to apply particulate material to components spaced apart along the machine direction. This means, however, that depending on the extent of the target area along the machine direction and the spacing of the components along the machine direction, individually adapted metering rollers must be manufactured, kept in stock, and used.

[0006] DE102021006409.7 (still unpublished) describes a device and a method for applying particulate material using a metering roller with cavities, which is controlled in a clocked manner, i.e., accelerated and decelerated according to the machine cycle, in order to bring a predetermined number of cavities filled with particulate material into a dispensing position per cycle. It was found that under certain circumstances, for example with very fine powdery materials, the dispensing of the cavity contents can be partially incomplete, which can lead to a risk of inaccurate dosing.

[0007] The present invention aims to provide a method and a device for more accurately dosing and precisely applying a small amount of particulate material in a high-speed manufacturing machine for absorbent hygiene products.

[0008] This task is solved by a method of the type mentioned above, wherein the metering roller is controlled in a clocked manner, i.e., accelerated and decelerated according to the movement of the components being passed, so that with each clock cycle a number of cavities are brought into a dispensing position for the component that has just been passed and the particulate material contained therein is applied to the component, and wherein the metering roller is rotated by a rotation angle α of more than 30° and less than 120° per clock cycle.

[0009] It has been found according to the invention that the problem of more precise dosing and targeted application of small quantities of particulate material during clocked, i.e., intermittent, operation of the dosing roller can be satisfactorily solved by such a preset rotation angle α, and that this also enables economical operation of the manufacturing machine for hygiene products. With a rotation angle α of more than 30° per cycle, the dosing roller can achieve a longer acceleration time and thus a higher maximum rotational speed at a given machine speed, i.e., at a given speed of the components being conveyed, than with a smaller rotation angle of the dosing roller.In this process, the particulate material transported in the cavities can be accelerated to a higher speed, and during the subsequent deceleration, the particulate material transported in the cavities to the discharge position can be more easily released and / or ejected from the cavities at the discharge position. A discharge position of the cavities of the metering roller is understood to mean that these cavities are exposed to the target structure, i.e., no longer covered by device components, in particular a doctor blade device preventing their emptying, so that the particulate material contained therein is dispensed with the assistance of gravity and / or centripetal accelerations of the metering roller and / or the acceleration and deceleration of the metering roller, and preferably reaches or is guided directly or indirectly onto the target structure.

[0010] With such a rotation angle α of more than 30°, a predetermined quantity of particulate material can be applied to a target structure with precise quantity and target accuracy, while conserving resources and machine resources, using a clocked and therefore intermittent drive of the metering roller.

[0011] With a very large rotation angle per cycle, the risk of the metering roller and / or the drive overheating or being subjected to increased wear could be elevated, especially at high cycle rates in very fast-running machines. Limiting the rotation angle α upwards can therefore protect the machine and reduce wear, while maintaining the beneficial effect on metering accuracy.

[0012] It proves advantageous if the metering roller is rotated by the angle of rotation α of 35° to 100°, in particular 40° to 90°, and further in particular 45° to 60° per cycle.

[0013] The same dosing roller can be used to produce hygiene products with varying amounts of particulate material to be applied to each product. Depending on the desired dose or quantity of particulate material, the rotation angle of the dosing roller is selected for each cycle. The larger the rotation angle per cycle, the more cavities filled with particulate material reach the dispensing position and are emptied. This allows for virtually stepless adjustment of the dosage quantity per product. Since the cavities can also be very small, even small quantities of particulate material can be precisely dosed and applied.

[0014] Furthermore, it proves advantageous if the particulate material is applied with a discharge angle β of at least 0°, in particular greater than 0°, and / or of at most 90°, in particular from 5° to 80°, in particular from 10° to 70°, in particular from 15° to 60°. The discharge angle is an angle to be determined in the radial cross-section of the metering roller, an angle enclosed by a radial line intersecting the discharge position and a cross-sectional center of the metering roller, and by a perpendicular extending from the cross-sectional center of the metering roller.

[0015] Preferably, the discharge position is spaced apart from the vertical line emanating from the cross-sectional center of the metering roller and is located, in particular, upstream of the vertical line of the metering roller in the machine direction.

[0016] It proves advantageous if the metering roller is accelerated to a maximum rotational speed in each cycle and then decelerated by at least 30%, particularly by at least 50%, and further, particularly by at least 70% of the maximum rotational speed, and further, particularly, decelerated to a standstill. This is particularly beneficial at high cycle rates in high-speed machines with a high maximum rotational speed of the metering roller, which has a beneficial effect on, or supports, the complete emptying of the cavities. It proves advantageous that, using the method according to the invention, even particulate material with less than optimal flowability can be completely dispensed from the cavities and applied to the target component.While typical superabsorbent particulate materials have a particle size predominantly larger than 300 µm and can be considered free-flowing (i.e., at least 80% by weight of a particle fraction is retained by a sieve with 300 µm openings during a residue analysis), this can be problematic with finer, more powder-like particulate materials. Nevertheless, the clocked, intermittent drive of the metering roller allows even particulate materials with a particle size predominantly smaller than 300 µm (at least 80% by weight of a particle fraction passes through a sieve with 300 µm openings during a residue analysis) to be applied with high metering accuracy, as the material is dispensed from the cavities without leaving any residue for practical applications.

[0017] Preferably, the maximum rotational speed v of the metering roller is 0.2 to 3.0 m / s, particularly 0.3 to 2.0 m / s, and more particularly 0.5 to 1.5 m / s. This refers to the speed at the outer circumferential surface of the roller.

[0018] The present invention proves to be particularly advantageous when a machine speed of at least 100 components of the hygiene articles to be manufactured per minute, in particular at least 200 components of the hygiene articles to be manufactured per minute, in particular at least 300 components of the hygiene articles to be manufactured per minute, in particular at least 400 components of the hygiene articles to be manufactured per minute, in particular about 500 components of the hygiene articles to be manufactured per minute is operated.

[0019] Furthermore, the invention proves to be particularly advantageous when a machine speed of more than 500 components of the hygiene products to be manufactured per minute, in particular at least 1000 components of the hygiene products to be manufactured per minute, and further, in particular, approximately 1500 components of the hygiene products to be manufactured per minute, is achieved. Such machine speeds are conceivable, for example, in the production of small hygiene products such as incontinence pads or panty liners.

[0020] In particular, it proves advantageous to operate at a machine speed of at least 1 m / s, particularly at least 2 m / s, particularly at least 3 m / s, particularly at least 4 m / s, and further, particularly at least 5 m / s, during component feeding. This results in the target area of ​​the component being located vertically below the metering roller for only 20–100 ms, particularly 40–60 ms, and typically only 50 ms. Accordingly, the metering roller must be controlled in a timed manner. Due to the high cycle rates, short dwell time of the target area in the target zone, and the high machine speed, a higher rotational speed of the metering roller can be achieved, which has a beneficial effect on, or further supports, complete emptying of the cavities.

[0021] Furthermore, with regard to precise positioning and in view of a tangential component of the particulate material when dispensing or ejecting it from the cavities at the dispensing position, it proves advantageous if a guiding arrangement is located downstream of the dispensing position of the cavities, by means of which particulate material ejected from the cavities is directed towards the target structure or a target area of ​​the target structure.

[0022] In this context, it proves advantageous if the guide arrangement has a baffle or guide wall which preferably includes an angle of inclination γ between 90° and 20°, in particular between 90° and 25°, in particular between 80° and 25°, in particular between 60° and 25° and further in particular between 50° and 25° to a horizontal plane.

[0023] It is also conceivable and advantageous if the impact or guide wall, depending on its positioning relative to the outer circumferential surface of the metering roller in the dispensing position, includes different angles to the horizontal plane.

[0024] Alternatively, the impact or guide wall can have a curved cross-section, preferably a convex or concave profile. Particularly when the vertical distance between the components passing the metering roller and the metering roller is small, as described below with reference to a device according to the invention, an angle of inclination γ of less than 20° between the impact or guide wall and a horizontal plane, in particular from 0° to 10°, or a slightly curved profile of the impact or guide wall can also be advantageous.

[0025] The cavities in the metering roller are designed to precisely receive and completely dispense particulate material when moved into the dispensing position and, in particular, slowed down until the roller comes to a complete stop. Therefore, they should be designed with a well-defined receiving volume (cavity volume). Furthermore, good emptying capability must be ensured. With regard to this aspect, it proves advantageous to incorporate inwardly tapered cavities, especially rounded, dome-shaped, or cup-shaped cavities, in the metering roller. Cavities without internal corners or edges have proven particularly beneficial for complete emptying.

[0026] To support complete emptying of the cavities in the dispensing position, it proves advantageous if the cavities in a transition to the outer circumferential surface of the metering roller are bounded by a wall with an opening angle greater than 0°, in particular at least 10°, further in particular at least 20°, further in particular at least 25°, in particular at least 30°, further in particular at least 35°, further in particular at least 40°, further in particular at least 45°, further in particular at least 55°.

[0027] Preferably, the opening angle of the cavities in a direction parallel to the drive axis of the metering roller is equal to or greater than in a direction of rotation of the metering roller. This allows the forces arising from acceleration and / or deceleration during intermittent operation to contribute more effectively to complete emptying of the cavities.

[0028] It is advantageous if each of the cavities in the outer circumferential surface of the metering roller has a cavity opening with a clear cross-sectional area and a cylindrical surface adjacent to the outer circumferential surface of the metering roller and a cavity volume enclosed jointly by the cylindrical surface and the clear cross-sectional area, wherein a ratio of the cavity volume to the clear cross-sectional area preferably has a value of 0.5 to 3.0 mm³ / mm², more preferably 0.5 to 2.0 mm³ / mm², more preferably 0.6 to 1.5 mm³ / mm², more preferably 0.6 to 1.0 mm³ / mm².

[0029] Furthermore, it proves advantageous if the cavity volume is at least 6 mm³, in particular at least 8 mm³, in particular at least 10 mm³, in particular at least 12 mm³, in particular at least 14 mm³. It also proves advantageous if the cavity volume is at most 50 mm³, in particular at most 40 mm³, in particular at most 35 mm³.

[0030] Preferably, each of the cavities has a cavity depth that is measured orthogonally to the clear cross-sectional area, wherein the ratio of the cavity volume to the respective cavity depth preferably has a value of 5.0 to 80.0 mm³ / mm, more preferably 6.0 to 60.0 mm³ / mm, more preferably 8.0 to 50.0 mm³ / mm, more preferably 10.0 to 30.0 mm³ / mm, more preferably 12.0 to 20.0 mm³ / mm.

[0031] Furthermore, it proves advantageous if the cavity depth is at least 0.8 mm, in particular at least 0.9 mm, in particular at least 1.0 mm, in particular at least 1.1 mm, and / or at most 4.0 mm, in particular at most 3.0 mm.

[0032] Preferably, the ratio of the clear cross-sectional area to the respective cavity depth has a value of 5.0 to 80.0 mm² / mm, more preferably 6.0 to 60.0 mm² / mm, more preferably 8.0 to 40.0 mm² / mm, more preferably 10.0 to 30.0 mm² / mm, more preferably 12.0 to 25 mm² / mm.

[0033] The clear cross-sectional area of ​​the cavities is preferably circular, oval or elliptical.

[0034] Furthermore, it proves advantageous if a largest dimension of the clear cross-sectional area of ​​a cavity in the outer circumferential surface of the metering roller is at least 2.5 mm, in particular at least 3.0 mm, and further in particular at least 3.5 mm, and / or at most 9.0 mm, in particular at most 8.5 mm, and further in particular at most 8.0 mm.

[0035] Preferably, the cavities in the outer circumferential surface of the metering roller are arranged in rows running parallel to a drive axis of the metering roller.

[0036] Preferably, the cavities in the outer circumferential surface are arranged offset from each other from row to row in the direction of the drive axis.

[0037] In an advantageous embodiment, 3 to 20 cavities are brought into the dispensing position per cycle, in particular 4 to 17, and further in particular 5 to 14.

[0038] In a further advantageous embodiment, more than one row of cavities, in particular two rows of cavities, are brought into the dispensing position per cycle. In an alternative embodiment, exactly one row of cavities is brought into the dispensing position per cycle. This can prove particularly advantageous at very high machine speeds and / or with relatively small target areas.

[0039] With regard to achieving high metering accuracy, it proves advantageous for the cavities to be designed and arranged on the outer circumferential surface of the metering roller in such a way that they are fully exposed in the dispensing position, i.e., not partially covered and partially exposed by a doctor blade or its cutting edge. This can be achieved very easily, for example, if the cavities on the outer circumferential surface of the metering roller are arranged in rows parallel to a drive axis of the metering roller.

[0040] The cavities do not necessarily have to be arranged in a strict square pattern. It can also be advantageous to arrange the cavities in the outer circumferential surface staggered from row to row in the direction of the drive axis. In this way, a higher density of cavities can be achieved on the outer circumferential surface.

[0041] It can also prove conceivable and advantageous if the cavities in the outer circumferential surface of the metering roller are arranged in groups spaced apart from each other in the circumferential direction. This allows for a cavity-free web to be formed between these groups in the circumferential direction. A doctor blade can then be positioned and resting on this web between two successive groups of cavities, with one group in the dispensing position and the other group still in front of the dispensing position and covered by the doctor blade.

[0042] It may prove advantageous if the outside diameter of the metering roller is at least 60 mm, in particular at least 70 mm, in particular at least 80 mm, and in particular at most 350 mm, in particular at most 320 mm, in particular at most 300 mm, in particular at most 250 mm, in particular at most 200 mm, in particular at most 150 mm.

[0043] As already mentioned at the outset, the present invention relates in particular to a method in which a small amount of particulate material of at most 2.0 g, in particular at most 1.5 g, in particular at most 1.2 g, in particular at most 1.0 g, in particular at most 0.8 g, is applied per component and cycle. In particular, even smaller amounts of particulate material, such as at most 0.5 g, in particular at most 0.3 g, and further, in particular at most 0.2 g, can be applied more reliably using the method according to the invention.

[0044] The invention further relates to a device for dosing and applying a small quantity of a particulate material in a high-speed manufacturing machine for absorbent hygiene products, wherein components of the hygiene products to be manufactured are successively fed and conveyed in the manufacturing machine as the target structure for the particulate material to be applied, comprising a metering roller with cavities provided in its outer circumferential surface for receiving the particulate material, and a doctor blade device with a doctor blade blade bearing against the outer circumferential surface of the metering roller, wherein the successively fed components are guided past and preferably below the metering roller and preferably at a distance from the metering roller, and comprising a control device and drive device for the metering roller, wherein the control and drive device is designed such that the metering roller can be controlled in a clocked manner.The system is accelerated and decelerated according to the movement of the components being passed, so that with each cycle a number of cavities are brought into a dispensing position for the component that has just been passed and the particulate material contained therein is applied to the component, characterized in that a rotation angle α of the metering roller per cycle is greater than 30° and less than 120°.

[0045] The inventors have determined that the device with such a rotation angle advantageously supports complete emptying of the cavities and, at the same time, machine-friendly operation of the manufacturing machine.

[0046] The device can preferably be designed such that the rotation angle α of the metering roller per cycle is in particular 35° to 100°, further in particular 40° to 90°, further in particular 45° to 60°.

[0047] The device can advantageously be designed such that the metering roller can be controlled in such a timed manner that it is accelerated in each cycle up to a maximum rotational speed and decelerated by at least 30%, in particular by at least 50%, and further in particular by at least 70% of the maximum rotational speed, and further in particular decelerated to a standstill.

[0048] This can be particularly advantageous at high cycle rates in high-speed machines, ensuring complete emptying of the cavities.

[0049] The device can advantageously be designed such that an outer surface of the metering roller is pre-treated to reduce wear, in particular by surface hardening and polishing, or coated, and in particular by hard chrome plating.

[0050] For a surface-hardened and polished outer surface of the metering roller, it has proven advantageous if the outer surface has a Rockwell hardness of 60+3 HRC after wear-reducing pretreatment.

[0051] For a hard-chrome plated outer surface of the metering roller, it has proven advantageous if the outer surface has a coating thickness of 50+3 µm after the wear-reducing pretreatment.

[0052] The wear-reducing pretreatment can further reduce the risk of wear, such as scratches or material removal caused by friction of the metering roller against other parts of the device, such as the doctor blade assembly, thus advantageously supporting a long service life of the metering roller, trouble-free operation and more lasting metering accuracy.

[0053] It proves advantageous if a launch angle β is at least 0°, in particular greater than 0° and / or at most 90°, in particular 5° to 80°, further in particular 10° to 70°, further in particular 15° to 60°.

[0054] The discharge angle, as previously explained with reference to the method, is an angle to be determined in the cross-section of the metering roller, an angle enclosed by a radial line intersecting the discharge position and a cross-sectional center of the metering roller and a perpendicular line emanating from the cross-sectional center of the metering roller.

[0055] At such a discharge angle, the acceleration caused by the intermittent operation of the metering roller can advantageously guide the particulate material towards the target structure and apply it with greater positional accuracy. The particulate material is accelerated in the machine direction and, particularly at a discharge angle greater than 0°, can be combined with the passing target structures while avoiding excessive turbulence.

[0056] A particularly vertical distance between the components guided past the metering roller and the metering roller is advantageously more than 0.0 cm, in particular 0.2 - 15.0 cm, further in particular 0.4 - 10.0 cm, further in particular 0.6 - 8.0 cm, further in particular 0.8 - 6.0 cm, further in particular 1.0 - 5.0 cm, further in particular 2.0 - 4.5 cm.

[0057] This allows the particulate material to be advantageously distributed over a designated target area, while simultaneously enabling space-saving production in the manufacturing machine and higher speeds due to the relatively short path of the particulate material.

[0058] The device can advantageously be designed such that a guide arrangement is arranged downstream of the dispensing position of the cavities, by means of which particulate material dispensed from the cavities is guided in the direction of the target structure or a target area of ​​the target structure.

[0059] The device can advantageously be designed such that the guide arrangement has a baffle or guide wall which includes an angle of inclination γ between 90° and 20°, in particular between 90° and 25°, further in particular between 80° and 25°, further in particular between 60° and 25° and further in particular between 50° and 25° to a horizontal plane.

[0060] It is also conceivable and advantageous if the impact or guide wall of the device includes different angles to the horizontal plane depending on its positioning relative to the outer circumferential surface of the metering roller in the dispensing position.

[0061] Alternatively, the impact or guide wall can have a curved cross-section, preferably a convex or concave profile. Particularly when the vertical distance between the components passing the metering roller and the metering roller is relatively small, an angle of inclination γ of less than 20° between the impact or guide wall and a horizontal plane, especially 0° to 10°, or a slightly curved profile of the impact or guide wall can also be advantageous.

[0062] The device can advantageously be designed such that the metering roller has tapered cavities, in particular rounded tapered cavities, for example, dome-shaped or cup-shaped cavities. It has been found that cavities without internal corners or edges, in particular, can be emptied more completely.

[0063] The device can advantageously be designed such that the cavities in a transition to the outer circumferential surface of the metering roller are bounded by a wall with an opening angle greater than 0°, in particular at least 10°, further in particular at least 20°, further in particular at least 25°, in particular at least 30°, further in particular at least 35°, further in particular at least 40°, further in particular at least 45°, further in particular at least 55°.

[0064] Preferably, the opening angle of the cavities in a direction parallel to the drive axis of the metering roller is equal to or greater than in a direction of rotation of the metering roller. This allows the forces occurring during intermittent operation due to acceleration and / or deceleration to contribute more effectively to complete emptying of the cavities.

[0065] Preferably, the opening angle in the direction of rotation of the metering roller is at most 110°, in particular at most 90°, and more preferably at most 70°.

[0066] Preferably, the opening angle in the direction parallel to the drive axis of the metering roller is at most 150°, in particular at most 130°, and more preferably at most 110°.

[0067] The device can advantageously be designed such that each of the cavities in the outer circumferential surface of the metering roller has a cavity opening with a clear cross-sectional area and a cylindrical surface adjacent to the outer circumferential surface of the metering roller and a cavity volume enclosed jointly by the cylindrical surface and the clear cross-sectional area, wherein a ratio of the cavity volume to the clear cross-sectional area preferably has a value of 0.5 to 3.0 mm³ / mm², more preferably 0.5 to 2.0 mm³ / mm², more preferably 0.6 to 1.5 mm³ / mm², more preferably 0.6 to 1.0 mm³ / mm².

[0068] The device can advantageously be designed such that the cavity volume is at least 6 mm 3< , in particular at least 8 mm 3< , further in particular at least 10 mm 3< , further in particular at least 12 mm 3< , further in particular at least 14 mm 3< .

[0069] Furthermore, the device can advantageously be designed such that the cavity volume is at most 50 mm³, in particular at most 40 mm³, and in particular at most 35 mm³.

[0070] The device can advantageously be designed such that each of the cavities has a cavity depth to be measured orthogonally to the clear cross-sectional area, wherein the ratio of the cavity volume to the respective cavity depth preferably has a value of 5.0 to 80.0 mm³ / mm, more preferably 6.0 to 60.0 mm³ / mm, more preferably 8.0 to 50.0 mm³ / mm, more preferably 10.0 to 30.0 mm³ / mm, more preferably 12.0 to 20.0 mm³ / mm.

[0071] The device can advantageously be designed such that the cavity depth is at least 0.9 mm, in particular at least 1.0 mm, further in particular at least 1.1 mm, and / or at most 4.0 mm, in particular at most 3.0 mm.

[0072] The device can advantageously be designed such that the ratio of the clear cross-sectional area to the respective cavity depth preferably has a value of 5.0 to 80.0 mm² / mm, more preferably 6.0 to 60.0 mm² / mm, more preferably 8.0 to 40.0 mm² / mm, more preferably 10.0 to 30.0 mm² / mm, more preferably 12.0 to 25 mm² / mm.

[0073] The clear cross-sectional area of ​​the cavities is preferably circular, oval or elliptical.

[0074] The device can advantageously be designed such that a maximum dimension of the clear cross-sectional area of ​​a cavity in the outer circumferential surface of the metering roller is at least 2.5 mm, in particular at least 3.0 mm, further in particular at least 3.5 mm, and / or at most 9.0 mm, in particular at most 8.5 mm, further in particular at most 8.0 mm.

[0075] The device can advantageously be designed such that the cavities in the outer circumferential surface of the metering roller are arranged in rows running parallel to a drive axis of the metering roller.

[0076] The device can advantageously be designed such that the cavities in the outer circumferential surface are arranged offset from each other from row to row in the direction of the drive axis.

[0077] Furthermore, the device can advantageously be designed such that 3 to 20 cavities are brought into the dispensing position per cycle, in particular 4 to 17, and further in particular 5 to 14.

[0078] In a further advantageous embodiment, the device can be designed such that more than one row of cavities, in particular 2 rows of cavities, are brought into the dispensing position per cycle.

[0079] The device can advantageously be designed such that the cavities in the outer circumferential surface of the metering roller are arranged in groups that are spaced apart from each other in the circumferential direction, so that a cavity-free web area is formed between these groups in the circumferential direction.

[0080] The device can advantageously be designed such that the outside diameter of the metering roller is at least 60 mm, in particular at least 70 mm, in particular at least 80 mm, and in particular at most 350 mm, in particular at most 320 mm, in particular at most 300 mm, in particular at most 250 mm, in particular at most 200 mm, in particular at most 150 mm.

[0081] The device can advantageously be designed such that a small amount of particulate material of at most 2.0 g, in particular at most 1.5 g, in particular at most 1.2 g, in particular at most 1.0 g, in particular at most 0.8 g is applied per component and cycle.

[0082] In particular, the device according to the invention allows even smaller quantities of particulate material, such as a maximum of 0.5 g, in particular a maximum of 0.3 g, and further, in particular a maximum of 0.2 g, to be applied in a more reliable manner.

[0083] The invention further relates to a manufacturing machine for absorbent hygiene articles with a device for dosing and applying a small quantity of a particulate material, as described above and claimed in the attached patent claims.

[0084] Further features, details, and advantages of the invention will become apparent from the attached claims and from the accompanying drawings and the following description of the invention. The drawing shows: Figure 1 a sectional view through a device according to the invention for dosing and applying a small quantity of a particulate material, with components of a hygiene article to be manufactured passed below the device and downstream topsheet feeding; Figure 2 a view of a metering roller unit of the device according to Figure 1 seen in the direction of arrow II in Figure 1 ; Figure 3 a perspective view of the metering roller unit after Figure 2 ; Figure 4 another perspective view of the metering roller unit after Figure 2 ; Figures 5 and 6 various patterns of cavity arrangement on the metering roller; Figures 7 ad , 8 ad and 9 aeVarious views of different metering rollers with drive shaft and details of the respective cavities; Figures 10a-h Further exemplary arrangements of the cavities by a radial view of a respective metering roller; Figures 11a and 11b Each a cross-sectional view through a dosing unit with a different discharge angle β.

[0085] Figure 1Figure 2 shows a device, designated in its entirety by reference numeral 2, for dosing and applying a small quantity of a particulate material 3, for example, in the form of a pH regulator, in a manufacturing machine 4 for absorbent hygiene products, which is only partially indicated. Only a portion of this manufacturing machine 4 is shown, in which a carrier material web 8, fed continuously in a machine direction 6, for example, to form a backsheet of the hygiene product, is fed with absorbent bodies 10 arranged at intervals from each other in the machine direction 6 and is passed, by way of example and preferably, below the device 2. Downstream of the device 2, another continuous material web 12, for example, in the form of a liquid-permeable topsheet of the hygiene product, is then fed, so that each absorbent body 10 is sandwiched between the carrier material web 8 and the material web 12.

[0086] Each absorption body 10, fed in the machine direction 6, forms a component 14 of a hygiene article to be manufactured, into or onto which a specific predetermined quantity of the particulate material 3 is to be applied as precisely as possible as a target structure 16. For this purpose, the device 2 includes a storage container 18 for receiving the material. Figure 1 only indicated particulate material 3 and a metering roller 20, which is attached in or at a lower opening 19 of the storage container 18 in such a way that it is exposed to the particulate material 3 inside the storage container 18 with a part of its outer circumferential surface 22 and seals the opening 19 of the storage container 18 in a substantially particle-tight manner in the remainder and together with a doctor blade device 24 or its doctor blade cutting edge 26.

[0087] As mentioned, the metering roller 20 has an outer circumferential surface 22 in which a multitude of cavities 28 are formed for receiving the particulate material 3.

[0088] The Figures 2 to 4 Further illustrations show device 2 for better visualization, omitting other components of the Figure 1 It can be seen that the storage container 18 together with the dosing roller 20 rotatably mounted therein forms a modular-looking dosing unit 30, which as a whole can be attached to or integrated into the high-speed production machine 4.

[0089] When the metering roller 20 with its cavities 28 comes into contact with the particulate material 3 inside the storage container 18, the cavities 28 fill with this particulate material 3. The release of this material 3 outside the metering unit 30 is achieved by the doctor blade 24, located below the metering roller 20, with its doctor blade 26, and by a sealing element 32 in the respective area of ​​the transition between the outer circumferential surface 22 and the adjacent axial end face of the metering roller 20. The sealing element 32 is advantageously designed as a somewhat flexible plastic sealing element and consists only of Figures 2 to 4As can be seen, the interior of the device 2, or rather its storage container 18, is effectively sealed against the environment and the manufacturing machine 4. Only when the respective cavities 28 of the metering roller 20 are released by the doctor blade 26 can the small and precisely metered quantity of particulate material contained therein be dispensed towards the component 14 of the hygiene product. In the passage of the components 14 shown here, this can be achieved, for example, below and at a vertical distance of 0.2–15.0 cm from the metering roller 20, with the aid of gravity. Furthermore, centripetal accelerations arise as a result of the rotation of the metering roller 20, which will be explained later, and tangential components with respect to this rotation also occur when the particulate material 3 is dispensed from the cavities 28 as they are rotated into a dispensing position 40 immediately following the doctor blade assembly 24.Therefore, the particulate material 3 does not flow from the cavities 28 onto the components 14 along a dashed arrow 42, i.e., exactly in a vertical direction, but rather follows a path more or less oblique to this direction, which is only schematically indicated by a slanted arrow 44. The material can and likely will follow an arc-shaped path (not shown). To support precise application, a guide arrangement 46 with a baffle or guide wall 48 is also provided, which has different angles of inclination γ to the horizontal. For example, the angle of inclination γ of the baffle or guide wall 48 is almost 90° in an upper region, and approximately 40° in a lower region. Alternatively, the baffle or guide wall can also have a curved or bent profile.

[0090] According to the invention, the metering roller 20 is not driven at a constant continuous rotational speed, but is controlled in a clocked manner and thereby accelerated and decelerated according to the movement of the components 14 being passed by, preferably decelerating to a standstill, so that with each clock cycle a number of cavities 28 are brought into the dispensing position 40 with respect to the component 14 that has just passed by and the particulate material 3 contained therein is applied to the component 14. It was found that this allows for a much more precise metering of particulate material and its dispensing to a respective component. This is achieved by means of a correspondingly clocked control system using an electronic control device 50 and a drive device 52 (in Figure 2(schematically indicated) it can be achieved that a predetermined number of cavities 28, corresponding to a rotation angle selected for each cycle for the metering roller 20, reach the dispensing position 40. Due to the high accelerations and decelerations resulting from the rotation angle α of more than 30° according to the invention, the complete dispensing of the particulate material 3 from each cavity 28 brought into the dispensing position 40 is achieved. This can be further supported by a shaping of the cavities 28, which will be described later, and / or by treating an outer surface of the metering roller 20, in particular including a cylindrical surface of the cavities 28, by hardening or coating, for example hard chrome plating, and / or by forming the surface of the metering roller 20 forming the cavities 28 from polished hard metal.

[0091] Limiting the rotation angle α to less than 120° reduces the risk of overheating of the metering roller and / or the drive device, which is particularly beneficial for high-speed machines, i.e., at high cycle rates, as it protects the machine and reduces wear.

[0092] As in Figure 1 as exemplified and also in Figures 5 and 6 As shown, the cavities 28 are arranged in rows 58 parallel to a geometric drive axis 56. Furthermore, it can be seen in Figure 1 and 6 , that the cavities are arranged in groups 60 of three rows 58 each, which are spaced apart from each other in the circumferential direction 61. Figures 2-4The figures show exemplary groups of two rows each. In this way, a cavity-free web area 62 is formed between the groups 60, which is suitable for the positioning of the doctor blade 26 after an incremental movement of the metering roller 20. However, it is also conceivable and advantageous if the cavities 28 are arranged in a more or less uniform distribution on the outer circumferential surface 22. It proves advantageous if the arrangement is such that a doctor blade can bear against the outer circumferential surface of the metering roller at a multitude of incremental rotational positions of the metering roller without overlapping a cavity. In this way, a defined number of cavities 28 can then be completely brought into the dispensing position 40.

[0093] The Figures 7a to 7dFigure 1 shows the metering roller 20 with bearing sections 66 of its drive shaft 68. It is preferably designed as a hollow roller. The arrangement of the cavities 28 is again exemplified in groups 60 of, for example, two rows 58 of cavities 28 each, wherein the groups 60 are spaced apart from each other by a cavity-free web area 62. Figure 7c (Sectional view according to level BB in Figure 7a The division of a circle segment is given as an example. The rotation angle of the metering roller 20 is, for example, 22.5°, which corresponds to 1 / 16 of a full revolution of the metering roller.

[0094] Detail C according to Figure 7dFigure 1 shows that the cavities 28 taper radially inwards. Advantageously, they are rounded and, in their radially inward apex, are cap-shaped, particularly in sections spherical cap-shaped. The cavities 28 have a circular clear cross-sectional area. It can also be seen that the cavities 28 are bounded at a transition to the outer circumferential surface of the metering roller by a wall with an opening angle of 40°, given here as an example. However, the dimensions (in millimeters) of the cavities in the figures are purely exemplary.

[0095] The Figures 8a to 8dFigure 1 shows the metering roller 20 with bearing sections 66 of its drive shaft 68. It is preferably designed as a hollow roller. The arrangement of the cavities 28 is again exemplified in groups 60 of, for example, two rows 58 of cavities 28 each, wherein the groups 60 are spaced apart from each other by a cavity-free web area 62. Figure 8c (Sectional view according to level EE in Figure 8a A circular segment division is given as an example. The rotation angle of the metering roller 20 is, for example, 45°, which corresponds to 12.5% ​​of a full revolution of the metering roller.

[0096] Detail F according to Figure 8dFigure 1 shows that the cavities 28 taper radially inwards. Advantageously, they are rounded and flattened in their radially inward apex, particularly in their lateral sections, forming a spherical cap. The cavities 28 have a circular clear cross-sectional area. It can also be seen that the cavities 28 are bounded at a transition to the outer circumferential surface of the metering roller by a wall with an opening angle of 23°, given here as an example. However, the dimensions (in millimeters) of the cavities in the figures are purely exemplary.

[0097] The Figures 9a to 9eFigure 1 shows the metering roller 20 with bearing sections 66 of its drive shaft 68. It is preferably designed as a hollow roller. The arrangement of the cavities 28 is again exemplified in groups 60 of, for example, two rows 58 of cavities 28 each, wherein the groups 60 are spaced apart from each other by a cavity-free web area 62. Figure 9c (Sectional view according to level HH in Figure 9a A circular segment division is given as an example. The rotation angle of the metering roller 20 is, for example, 45°, which corresponds to 12.5% ​​of a full revolution of the metering roller.

[0098] Detail J according to Figure 9d and detail K according to Figure 9eFigure 1 shows that the cavities 28 taper radially inwards. They are advantageously rounded and dome-shaped in their radially inward apex, with an oval or elliptical clear cross-sectional area. A dimension of the clear cross-sectional area of ​​a cavity in the outer circumferential surface of the metering roller, measured parallel to the drive shaft (also referred to above as the drive axis), has a different value (9.0 mm in). Figure 9d ), here, for example, a larger value, measured parallel to a direction of rotation of the metering roller (5.1 mm in Figure 9e In this example, one of the largest dimensions of the clear cross-sectional area of ​​a cavity in the outer circumferential surface of the metering roller extends parallel to the drive shaft. Based on the Figure 9dIt can further be seen that the cavities 28, in the direction parallel to the drive shaft, are bounded in a transition to the outer circumferential surface of the metering roller by a wall with an opening angle, here given as an example of 106°. Based on the Figure 9e It can further be seen that the cavities 28, in the direction of rotation of the metering roller, are bounded at a transition to the outer circumferential surface of the metering roller by a wall with an opening angle of 64°, given here as an example. However, the dimensions (in millimeters) of the cavities in the figures are purely exemplary.

[0099] The Figures 10a-10hFurther exemplary cavity arrangements are shown by a radial view of a respective metering roller. The closer the cavities are arranged to each other, the greater the application volume of particulate material is available per revolution of the metering roller. A smaller number of cavities, as for example in Figure 8a and Figure 9a , however, can further support more precise application and / or the dosage of a smaller amount of particulate material, thus conserving material resources.

[0100] The Figures 11a and 11b Each figure shows a sectional view of exemplary dosing units of the device with different discharge angles β, omitting other components for better illustration. Figure 1A discharge position 40 immediately following a doctor blade device 24 is located upstream of the vertical line 59 extending from the cross-sectional center 57 of the metering roller 20 in the machine direction 6. The discharge angle β is an angle to be determined in the radial cross-section of the metering roller 20, namely an angle enclosed by a radial line 55 intersecting the discharge position 40 and the cross-sectional center 57 of the metering roller 20 and by the vertical line 59 extending from the cross-sectional center 57 of the metering roller 20. In the Figure 11a In the example shown, the launch angle β is 17°. In the example shown Figure 11b In the example shown, the launch angle β is 47°.

Claims

1. Method for metering and applying a small amount of a particulate material in a high-speed manufacturing machine (4) for absorbent hygiene articles, wherein components (14) of the hygiene articles to be produced are successively supplied and conveyed in the manufacturing machine (4) as a target structure (16) for the particulate material that is to be applied, wherein a metering roller (20) with cavities (28) provided in its outer circumferential surface (22) is used to receive the particulate material, wherein the successively supplied components (14) are guided past and preferably below the metering roller (20) and preferably at a distance from the metering roller (20), wherein the metering roller (20) is controlled in a clocked manner, i.e. is accelerated and decelerated according to the movement of the components (14) guided past, so that with each clock cycle a number of cavities (28) are brought into a discharge position (40) with respect to the component (14) just guided past, and particulate material contained in the cavities is applied to the component (14), and wherein the metering roller (20) is rotated by an angle of rotation α of more than 30° and less than 120° per clock cycle.

2. Method according to Claim 1, characterized in that the metering roller (20) is rotated, per clock cycle, by the angle of rotation α of 35° to 100°, in particular 40° to 90°, more particularly 45 to 60°.

3. Method according to one or more of the preceding claims, characterized in that the particulate material is applied with a throw-off angle β of at least 0°, in particular of greater than 0° and / or of at most 90°, in particular of 5° to 80°, more particularly of 10° to 70°, more particularly of 15° to 60°.

4. Method according to one or more of the preceding claims, characterized in that the metering roller (20) is accelerated in each clock cycle up to a maximum rotational speed and decelerated by at least 30%, in particular by at least 50%, more particularly by at least 70% of the maximum rotational speed, more particularly decelerated until it comes to a standstill.

5. Method according to one or more of the preceding claims, characterized in that the discharge position (40) of the cavities is followed downstream by a guide arrangement (46) by means of which particulate material discharged from the cavities (28) is guided in the direction of the target structure (16) or a target region of the target structure (16), wherein the guide arrangement (46) has a baffle or guide wall (48) which, with respect to a horizontal plane, preferably encloses an angle of inclination γ of between 90° and 20°, in particular of between 90° and 25°, in particular of between 80° and 25°, in particular of between 60° and 25°, and more particularly of between 50° and 25°.

6. Device (2) for metering and applying a small amount of a particulate material in a high-speed manufacturing machine (4) for absorbent hygiene articles, wherein components (14) of the hygiene articles to be produced are successively supplied and conveyed in the manufacturing machine (4) as a target structure (16) for the particulate material that is to be applied, having a metering roller (20) with cavities (28) provided in its outer circumferential surface (22) for the purpose of receiving the particulate material, and having a doctor device (24) with a doctor blade (26) resting against the outer circumferential surface (22) of the metering roller (20), wherein the successively supplied components (14) are guided past and preferably below the metering roller (20) and preferably at a distance from the metering roller (20), and having a control device (50) and drive device (52) for the metering roller (20), wherein the control device (50) and drive device (52) are designed in such a way that the metering roller (20) can be controlled in a clocked manner, i.e. is accelerated and decelerated according to the movement of the components (14) being guided past, so that with each clock cycle a number of cavities (28) are brought into a discharge position (40) with respect to the component just guided past, and particulate material contained in the cavities is applied to the component (14), and wherein an angle of rotation α of the metering roller is greater than 30° and less than 120° per clock cycle.

7. Device according to Claim 6, characterized in that the angle of rotation α of the metering roller per clock cycle is in particular 35° to 100°, more particularly 40° to 90°, more particularly 45° to 60°.

8. Device according to one or both of preceding Claims 6 and 7, characterized in that an outer surface of the metering roller is pre-treated to reduce wear, in particular surface-hardened and polished, or coated, more particularly hard-chrome plated.

9. Device according to one or more of preceding Claims 6 to 8, characterized in that a throw-off angle β is at least 0°, in particular greater than 0° and / or at most 90°, in particular 5° to 80°, more particularly 10° to 70°, more particularly 15° to 60°.

10. Device according to one or more of preceding Claims 6 to 9, characterized in that an in particular vertical distance between the metering roller and the components guided past the metering roller is more than 0.0 cm, in particular 0.2 - 15.0 cm, more particularly 0.4 - 10.0 cm, more particularly 0.6 - 8.0 cm, more particularly 0.8 - 6.0 cm, more particularly 1.0 - 5.0 cm, more particularly 2.0 - 4.5 cm.

11. Device according to one or more of preceding Claims 6 to 10, characterized in that the discharge position (40) of the cavities (28) is followed downstream by a guide arrangement (46) by means of which particulate material discharged from the cavities (28) is guided in the direction of the target structure (16) or a target region of the target structure (16), wherein the guide arrangement (46) has a baffle or guide wall (48) which, with respect to a horizontal plane, preferably encloses an angle of inclination γ of between 90° and 20°, in particular of between 90° and 25°, more particularly of between 80° and 25°, more particularly of between 60° and 25° and more particularly of between 50° and 25°.

12. Device according to one or more of preceding Claims 6 to 11, characterized in that the cavities (28), in a transition to the outer circumferential surface of the metering roller (20), are delimited by a wall with an opening angle greater than 0°, in particular of at least 10°, more particularly of at least 20°, more particularly of at least 25°, in particular of at least 30°, more particularly of at least 35°, more particularly of at least 40°, more particularly of at least 45°, more particularly of at least 55°.

13. Device according to one or more of the preceding claims, characterized in that each of the cavities (28) in the outer circumferential surface of the metering roller (20) has a cavity opening with a clear cross-sectional area and a jacket surface adjoining the outer circumferential surface of the metering roller and a cavity volume enclosed jointly by the jacket surface and the clear cross-sectional area, wherein a ratio of the cavity volume to the clear cross-sectional area preferably has a value of 0.5 to 3.0 mm3 / mm2, more preferably of 0.5 to 2.0 mm3 / mm2, more preferably of 0.6 to 1.5 mm3 / mm2, more preferably of 0.6 to 1.0 mm3 / mm2.

14. Device according to preceding Claim 13, characterized in that each of the cavities has a cavity depth to be measured orthogonally to the clear cross-sectional area, wherein a ratio of the cavity volume to the respective cavity depth preferably has a value of 5.0 to 80.0 mm3 / mm, more preferably of 6.0 to 60.0 mm3 / mm, more preferably of 8.0 to 50.0 mm3 / mm, more preferably of 10.0 to 30.0 mm3 / mm, more preferably of 12.0 to 20.0 mm3 / mm.

15. Device according to preceding Claim 14, characterized in that a ratio of the clear cross-sectional area to the respective cavity depth preferably has a value of 5.0 to 80.0 mm2 / mm, more preferably of 6.0 to 60.0 mm2 / mm, more preferably of 8.0 to 40.0 mm2 / mm, more preferably of 10.0 to 30.0 mm2 / mm, more preferably of 12.0 to 25 mm2 / mm.