(56) References cited:

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1 (19) TEPZZ B_T (11) EP B1 (12) EUROPEAN PATENT SPECIFICATION (4) Date of publication and mention of the grant of the patent: Bulletin 17/23 (21) Application number: (22) Date of filing: (1) Int Cl.: A61F 13/ (06.01) B0B 7/14 (06.01) A61F 13/34 (06.01) A61F 13/3 (06.01) (86) International application number: PCT/IB14/06027 (87) International publication number: WO 14/ ( Gazette 14/43) (4) MACHINE AND METHOD FOR MAKING ABSORBENT SANITARY ARTICLES MASCHINE UND VERFAHREN ZUR HERSTELLUNG SAUGFÄHIGER HYGIENEARTIKEL MACHINE ET PROCÉDÉ POUR FABRIQUER DES ARTICLES HYGIÉNIQUES ABSORBANTS (84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR () Priority: IT BO1174 (43) Date of publication of application: Bulletin 16/08 (73) Proprietor: GDM S.p.A. 133 Bologna (IT) (72) Inventors: PIANTONI, Matteo I-221 Albino (Bergamo) (IT) SOLI, Valerio I-13 Bologna (IT) (74) Representative: Bianciardi, Ezio Bugnion S.p.A. Via di Corticella, Bologna (IT) (6) References cited: EP-A WO-A1-09/ WO-A1-00/12974 EP B1 Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). Printed by Jouve, 7001 PARIS (FR)

2 1 EP B1 2 Description Aim of the invention Technical field [0001] This invention relates to a machine and a method for making absorbent sanitary articles. Background art [0002] As is known, nappies comprise an impermeable layer, for example of polyethylene, a layer of non-woven fabric permeable to liquids and an absorbent pad sandwiched therebetween. [0003] Absorbent pads are made mainly from natural fibre material (known as "fluff") uniformly blended with superabsorbent polymer material ("SAP"). In order to increase pad absorption capacity absorbent pads have been developed which comprise one or more discrete absorbent layers made mainly from superabsorbent polymer material ("SAP"). [0004] It is known from the prior art that a unit for making absorbent pads for nappies comprises a drum, which rotates about its axis of rotation and which has on its peripheral cylindrical surface a plurality of suction housings or recesses within which respective absorbent pads are formed. An example of apparatus for making absorbent pads is disclosed at document EP23439A1. [000] The unit also comprises a hood which is used for feeding fluff mixed with "SAP" and which is located to face the peripheral cylindrical surface of the drum. [0006] The fluff and "SAP" are fed pneumatically into the hood and, once mixed, settle in the suction recesses formed on the drum and located to face the hood. [0007] It is also known that the unit comprises a feeding duct having a mouth for Intermittent valve means regulate the feed flow of the feeding duct as a function of the spacing of the drum recesses, so that discrete charges of superabsorbent polymer material ("SAP") are delivered exactly at the moment a suction recess of the drum comes to face the delivery mouth of the duct itself. [0008] It has been found, however, that on account of incorrect manual settings or mechanical malfunctions, the intermittent valve means go out of phase with the rotation of the drum and, consequently, the feeding duct does not deliver the discrete charges of superabsorbent polymer material when a suction recess only partly faces the duct delivery mouth or does not face the duct delivery mouth. [0009] This leads to the formation of defective absorbent pads because the discrete layers of superabsorbent polymer material in the respective pad are not positioned correctly relative to a reference position. [00] The incorrect position of the discrete layers of superabsorbent polymer material reduces the effective liquid absorbing capacity of the absorbent pad [0011] This invention has for an aim to provide a machine and a method for making absorbent sanitary articles, as described in the independent claim 1, and which can overcome the above mentioned disadvantages of the prior art. Brief description of the drawings [0012] The invention will now be described with reference to the accompanying drawings which illustrate a non-limiting embodiment of it and in which: Figure 1 is a schematic front view illustrating a machine for making absorbent sanitary articles according to this invention; Figure 2 is a schematic front view of a detail of a first embodiment of the machine of Figure 1; Figure 3 is a schematic perspective view of a detail of a second embodiment of the machine of Figure 1; Figure 4 is a schematic perspective view of a detail of a third embodiment of the machine of Figure 1; Figure is a schematic front view of a detail of the machine of Figure 1. Detailed description of preferred embodiments of the invention [0013] With reference to Figure 1, the numeral 1 denotes in its entirety a machine for making absorbent sanitary articles 32 which comprise a sheet of permeable material and a sheet of impermeable material having, sandwiched between them, an absorbent pad 2 constituting the part of the absorbent sanitary article 32 whose function is to absorb liquids. [0014] The absorbent pad 2 comprises at least a first absorbent material 37. [00] Preferably, the first absorbent material 37 is made mainly from natural fibre material (fluff) 3 uniformly blended with superabsorbent polymer material ("SAP") 4 [0016] Alternatively the absorbent pad 2 is made mainly or only from natural fibre material (fluff) 3 or superabsorbent polymer material ("SAP") 4. [0017] The absorbent pad 2 also comprises at least one discrete layer 19 of superabsorbent polymer material ("SAP") 4b defining a second absorbent material 38. [0018] Preferably, the superabsorbent polymer material 4, 4b used is superabsorbent polymer material in granular form. [0019] The machine 1 comprises a line for feeding at least one continuous web 6 of impermeable material used to make the above mentioned sheet of impermeable material. [00] The machine 1 comprises a unit 7 for forming and applying a succession 8 of absorbent pads 2 and located along the feed line. [0021] More specifically, the unit 7 is substantially tan- 2

3 3 EP B1 4 gent to the feed line at a release station 9. [0022] The unit 7 comprises a forming drum by which the absorbent pads 2 are formed. [0023] The drum is substantially tangent to the feed line at the release station 9. [0024] The drum has a horizontal axis of rotation perpendicular to the feed line. [002] On its peripheral surface, the drum has one or more suction recesses 11. [0026] The suction recesses 11 are located on the peripheral surface of the drum at a predetermined spacing P. [0027] As the drum rotates, absorbent pads 2 are gradually formed inside respective suction recesses 11 and, once completed, are released onto the feed line by the drum itself at the release station 9. [0028] The unit 7 comprises a hood 12 which is mounted in such a way as to peripherally face at least part of the peripheral surface of the drum. [0029] More specifically, the hood 12 feeds the forming drum. [00] The unit 7 comprises a first system 32 for metering the natural fibre material (fluff) 3 and a second system 33 for metering the superabsorbent polymer material ("SAP") 4 of the first absorbent material 37. [0031] The unit 7 also comprises a third system 34 for metering the superabsorbent polymer material ("SAP") 4b defining the discrete layer 36 of the absorbent pad 2, as illustrated in Figure. [0032] The first, second and third metering systems 32, 33, 34 are preferably connected to the feed hood 12. [0033] The third metering system 34 comprises at least one metering device 3 and one feeding duct 13 connected to the metering device 3 at the outfeed of the metering device 3 itself. [0034] More precisely, the duct 13 has a delivery mouth 14 leading to the hood 12. [003] The feeding duct 13 comprises valve means driven by an actuator unit. [0036] The valve means are located upstream of the delivery mouth 14 along a stretch of the feeding duct 13. [0037] More specifically, the valve means define a first stretch T1 of the duct 13 upstream of the valve means and a second stretch T2 of the duct 13 downstream of them. [0038] The valve means deliver charges of superabsorbent polymer material intermittently into the feeding duct 13, in particular into the second stretch T2 of the feeding duct 13. [0039] More precisely, the valve means deliver charges of superabsorbent polymer material 4 intermittently as a function of the spacing P of the suction recesses 11 of the drum. [00] Thus, the feeding duct 13 delivers charges of superabsorbent polymer material 4 when a suction recess 11 is facing the delivery mouth 14 of the duct 13 itself [0041] It should be noted that correct phasing between the valve means and the position of the recesses 11 of the drum guarantees correct positioning of the discrete layers 19 of superabsorbent polymer material in the recesses 11 of the drum and, hence, in the absorbent pad 2. [0042] In effect, in order to guarantee optimal liquid absorption, the discrete layer 19 is located at a predetermined reference position in the absorbent pad 2. [0043] The unit 7 comprises at least one device 16 for detecting the superabsorbent polymer material 4 located downstream of the valve means and a control and drive unit 17 connected to the detecting device 16. [0044] More specifically, the detecting device 16 sends a detection signal 18 each time the detection signal 16 detects the superabsorbent polymer material 4 defining the discrete layer 19. [004] The control and drive unit 17 is configured to acquire the detection signal 18 and to compare it with a predetermined reference signal 19. [0046] Based on the deviation between the detection signal 18 and the reference signal 19, the control and drive unit 17 is configured to drive the actuator unit of the valve means to bring the valve means into phase with the rotation of the forming drum. [0047] In a first embodiment, the detecting device 16 is configured to detect the passage of each charge of superabsorbent polymer material 4 in the feeding duct 13, in particular in the second stretch T2, and to send the detection signal 18 to the control and drive unit 17. [0048] It should be noted that since feed by the valve means is intermittent, the detecting device 16 detects the superabsorbent polymer material 4 in the feeding duct 13 intermittently. [0049] In this case, the reference signal 19 of the control and drive unit 17 is a sync signal of the drum which forms the absorbent pads 2. [000] The control and drive unit 17 compares the detection signal 18 with the sync signal of the drum and is configured to drive the actuator unit into phase with the sync signal of the drum if the deviation between the detection signal 18 and the reference signal 19 is such that the valve means are not in phase with the forming drum. [001] The detecting device 16 comprises a microwave resonator 21 which at least partly faces the inside of the feeding duct 13. [002] More specifically, the detecting device 16 comprises a microwave resonator 21 which at least partly faces the inside of the second stretch T2 of the feeding duct 13. [003] In an alternative embodiment not illustrated, the detecting device 16 is mounted along the feeding duct 13 upstream of the valve means. In this case, the metering device 3 feeds the charge of superabsorbent polymer material 4b into the feeding duct 13 intermittently and the detecting device 16 detects its passage before it enters the valve means. 3

4 EP B1 6 [004] In a second and a third embodiment, the device 16 for detecting the absorbent pad 2 is mounted along the feed line downstream of the unit 7 for forming and applying the succession 8 of absorbent pads 2. [00] In this case, the detecting device 16 is configured to detect the position 22 of the discrete layer 19 of superabsorbent polymer material 4 inside the absorbent pad 2. [006] By detected position 22 is meant the profile of the discrete absorbent layer 19 along a main longitudinal direction of extension of the absorbent pad 2. The device 16 for detecting the absorbent pad 2 sends the detected position 22 of the discrete layer 19 of superabsorbent polymer material 4 to the control and drive unit 17. [007] The control and drive unit 17 compares the position 22 detected by the detecting device 16 with a reference position 23 and calculates the deviation "d" between the detected position 22 and the reference position 23. [008] The control and drive unit 17 is configured to drive the actuator unit and to bring the valve means into phase with the rotation of the forming drum as a function of the deviation "d". [009] The detecting device 16 comprises a microwave resonator 21 which at least partly faces the succession 8 of the absorbent pads 2 advancing along the feed line. [0060] In the second embodiment of the machine 1, as illustrated in Figure 3, the feed line comprises at least one stretch where the feed line comprises a single conveyor belt 24 for conveying the continuous web 6 of impermeable material. [0061] The detecting device 16 is located along that stretch of the feed line. The detecting device 16 has a slot 2 through which at least the conveyor belt 17 and the succession 8 of absorbent pads conveyed thereby pass in and out [0062] More precisely, and preferably, the detecting device 16 is crossed by the conveyor belt 24, by the continuous web 6 of impermeable material and by the succession 8 of absorbent pads 2. [0063] The microwave resonator 21 is positioned to face the conveyor belt 24 and the succession 8 of absorbent pads 2. [0064] In the third embodiment, as illustrated in Figure 4, the feed line comprises at least one stretch having a first and a second conveyor belt 26 and 27 for conveying the continuous web 6 of impermeable material. The detecting device 16 is interposed between the first and second conveyor belts 26 and 27 in such a way that at least the continuous web 6 of impermeable material and the succession 8 of absorbent pads 2, conveyed by the first and second belts 26 and 27, pass through the detecting device 16. [006] Thus, the continuous web 6 of impermeable material and the succession 8 of absorbent pads 2 pass in and out through the slot 2 of the detecting device 16 [0066] The microwave resonator 21 is located to face the continuous web 6 of impermeable material and the succession 8 of absorbent pads 2. [0067] In other words, the third embodiment differs from the second embodiment in that no conveyor belt 26, 27 transporting the continuous web 6 of impermeable material passes through the detecting device 16. [0068] To allow the detecting device 16 to be mounted easily along the feed line, the detecting device 16 comprises at least one removable element 28. [0069] More specifically, once the removable element 28 has been removed, the conveyor belt 24 and/or the continuous web 6 of impermeable material, depending on the embodiment of the machine 1, can be inserted into the slot 2 of the detecting device 16. [0070] It should be noted that to properly inspect the absorbent pad 2, the detecting device 16 must be calibrated to detect only the superabsorbent polymer material 4 making up the discrete layers 19 of the pad 2. [0071] To calibrate the detecting device 16, it is necessary to make the elements to be excluded during detection of the position 22 of the discrete layers 19 of the absorbent pad 2 pass through the detecting device 16. [0072] The detecting device 16 is preferably calibrated during start-up of the machine 1. [0073] Thus, during the steady-state operation of the machine 1, the detecting device 16 excludes from detection the resonance curves relating to the components of the absorbent article 32 being formed along the feed line, with the exception of the superabsorbent polymer material 4 making up the discrete layers 19 of the absorbent pad 2 itself. [0074] In the second and third embodiments, the detecting device 16 is substantially in the shape of a parallelepiped. [007] The detecting device 16 comprises a top wall 29, a bottom wall and two side walls or flanks 31. [0076] Preferably, the removable element 28 is located along one of the flanks 31 of the detecting device 16. [0077] Preferably, the microwave resonator 21 is located at the top wall 29 of the detecting device 16. [0078] In use, during the passage of the succession of absorbent pads 2 through the slot 2, the detecting device 16 of the second and third embodiments is configured to detect the profile of the discrete absorbent layer 19, preferably step by step. [0079] More specifically, the profile detected is the profile of the discrete absorbent layer 19 along a main longitudinal direction of extension of the absorbent pad 2. [0080] The profile of the discrete absorbent layer 19 defines the position 22 detected by the detecting device 16. [0081] The detecting device 16 sends the detected position 22 to the control and drive unit 17 and the latter compares the position 22 with the reference position 23 and calculates its deviation "d". [0082] If the deviation "d" is such that the valve means are no longer in phase with the drum, the control and drive unit 17 drives the actuator unit to reset the 4

5 7 EP B1 8 valve means in phase with the drum. [0083] It should be noted that the position 22 detected by the detecting device 16 is the detection signal 18 of the detecting device 16 and the reference position 23 is the reference signal 19. [0084] Advantageously, the microwave resonator 21 of the detecting device 16 is capable of detecting distinctly one or more absorbent materials 3, 4, 4b defining the absorbent pad 2. [008] In other words, using the detecting device 16 with the microwave resonator 16 it is possible to detect, distinctly from each other, the weights and density profiles (or weight profiles) of the natural fibre material (fluff) 3, of the superabsorbent polymer material ("SAP") 4 of the first absorbent material 37 and of the superabsorbent polymer material ("SAP") 4b defining the discrete layer 36 of the absorbent pad 2. [0086] During its operation, the microwave resonator 21 emits waves at a certain resonance frequency and, depending on the material inspected, generates a certain resonance curve characterized by a resonance frequency and a mean resonance amplitude. [0087] Since each material is characterized by its own resonance curve, having a specific resonance frequency and a specific mean resonance amplitude, the detecting device 16 is capable of detecting and distinguishing each material making up the inspected object and to calculate its weight and/or density profile (or weight profile). [0088] The control and drive unit 17 is configured to receive from the detecting device 16 at least one between the weight, density profile (or weight profile) parameters of at least one of the absorbent materials 3, 4, 4b of the pad 2 and to compare it with a respective reference parameter. [0089] If the parameter detected by the detecting device 16 deviates from the reference parameter by more than a predetermined threshold value, the control and drive unit 17 is configured to drive, as a function of that deviation, the system 32, 33, 34 for metering the respective absorbent material 3, 4, 4b. [0090] Advantageously, to check the weight and/or density profile (or weight profile) of the discrete layer 36 of superabsorbent polymer material, the control and drive unit 17 is configured to receive from the detecting device 16 at least one between the weight, density profile (or weight profile) parameters of the superabsorbent polymer material 4b defining the discrete layer 36 and to compare it with a respective reference parameter. If the parameter detected by the detecting device 16 deviates from the reference parameter by more than a predetermined threshold value, the control and drive unit 17 is configured to drive, as a function of that deviation, the third system 34 for metering the respective superabsorbent polymer material 4b. [0091] The correct contribution in weight of the superabsorbent polymer material 4b defining the discrete absorbent layers 36 is fundamental for guaranteeing effective absorption of liquids by the absorbent pad [0092] If the deviation of the detected parameters from the reference parameters is such that the absorbent pad 2 must be considered defective, the control and drive unit 17 is configured to reject the article comprising the defective absorbent pad 2. [0093] This invention also relates to a method for making absorbent pads for nappies which comprise an absorbent pad 2 in turn comprising at least one discrete layer 19 of superabsorbent polymer material 4. [0094] The method comprises a step of feeding along a feed line at least one continuous web 6 of impermeable material and a step of forming and applying a succession 8 of absorbent pads 2 along the continuous web 6 by means of a forming and application unit 7. [009] The step of forming and applying a succession 8 of absorbent pads 2 comprises a step of feeding a charge of superabsorbent polymer material 4 to a forming drum through a feeding duct 13 comprising valve means driven by a specific actuator unit. [0096] The method comprises a step of sending a detection signal 18 indicating that the superabsorbent polymer material 4 has been detected and a step of comparing the detection signal 18 with a reference signal 19. [0097] As a function of the deviation between the detection signal 18 and the reference signal 19, the method comprises a step of driving the actuator unit of the valve means into phase with the drum. [0098] More specifically, in a first embodiment, the detection signal 18 indicating that the superabsorbent polymer material 4 has been detected is generated when the charge of superabsorbent polymer material 4 passes in the feeding duct 13 downstream of the valve means. [0099] In a second and a third embodiment, the step of sending a detection signal 18 indicating that the superabsorbent polymer material 4 has been detected comprises a step of detecting the position 22 of the discrete layer 19 of superabsorbent polymer material 4 and a step of comparing the detected position 22 with a reference position 23. [00] The method comprises a step of driving the actuator unit of the valve means into phase with the drum as a function of the deviation between the detected position 22 and the reference position 23. [01] The method comprises a step of detecting at least one between the weight, density profile (or weight profile) parameters of at least one of the absorbent materials 3, 4, 4b defining the absorbent pad 2. [02] The method further comprises a step of sending at least one between the weight, density profile (or weight profile) parameters of at least one of the absorbent materials 3, 4, 4b to a control and drive unit 17 and a step of comparing the detected parameter with a respective reference parameter. A yet further a step of the method comprises driving a system 32, 33, 34 for metering the respective absorbent material as a function of the deviation of the detected parameter from the reference parameter. [03] The detection step comprises a step of detect-

6 9 EP B1 ing at least one between the weight, density profile (or weight profile) parameters of the superabsorbent polymer material 4b defining the discrete layers 36 of the absorbent pad 2. The method comprises a step of sending at least one between the weight, density profile (or weight profile) parameters of the superabsorbent polymer material 4b to a control and drive unit 17 and a step of comparing the detected parameter with a respective reference parameter; and a step of sending a feedback drive signal to a system 34 for metering the superabsorbent polymer material 4b defining the discrete layers 36 of the absorbent pad 2 as a function of the deviation of the detected parameter from the reference parameter. [04] In the first embodiment, the step of detecting at least one between the weight, density profile (or weight profile) parameters of at least one of the absorbent materials 3, 4, 4b occurs during the formation of the absorbent pad 2 in the above mentioned unit 7 for forming and applying the succession 8 of absorbent pads 2. [0] In the second and third embodiments, the step of detecting at least one between the weight, density profile (or weight profile) parameters of at least one of the absorbent materials 3, 4, 4b occurs downstream of the unit 7 for forming and applying the absorbent pad 2. [06] Advantageously, the detecting device 16 makes it possible to detect whether or not the intermittent valve means are in phase with the forming drum and, if they are not in phase, to reset the actuator unit in phase with the forming drum by means of the control and drive unit 17. [07] Advantageously, detecting the position of the discrete layer 19 of superabsorbent polymer material constituting the discrete layers 19 of the pad 2 by means of the detecting device 16 allows considerable savings in terms of labour cost because it is no longer necessary for an operator to be present at the end of the feed line to check the correct position of the discrete layer 19. [08] Advantageously, the detecting device 16 comprising a microwave resonator 21 is not affected, in detecting the specified parameters, by external factors such as the temperature and humidity of the operating environment. [09] Moreover, the microwave resonator 21 allows distinguishing each absorbent material 3, 4, 4b defining the pad and to calculate the weight and density profile (or weight profile) of each material. Claims 1. A machine for making absorbent sanitary articles which comprise an absorbent pad (2) in turn comprising at least one discrete layer (19) of superabsorbent polymer material (4, 4b); the machine (1) comprising a line () for feeding at least one continuous web (6) of impermeable material and at least one unit (7) for forming and applying a succession (8) of absorbent pads (2) along the continuous web (6) of impermeable material; the forming and application unit (7) comprising a drum () for forming the absorbent pad (2), a duct (13) for feeding a charge of superabsorbent polymer material (4, 4b) to the forming drum () and intermittent valve means () mounted along a stretch (T) of the feeding duct (13) and driven by its own actuator unit (); the machine (1) being characterized in that it comprises a device (16) for detecting the superabsorbent polymer material (4, 4b) defining the discrete layer (19) of the absorbent pad (2) and a control and drive unit (17) connected to the detecting device (16); the detecting device (16) sending a superabsorbent polymer material detection signal (18) and the control and drive unit (17) being configured to acquire the detection signal (18) and to compare it with a reference signal (19); the control and drive unit (17) being configured to drive the actuator unit () to bring the valve means () into phase with the rotation of the forming drum () if the deviation of the detection signal (18) from the reference signal (19) exceeds a defined threshold value. 2. The machine according to claim 1, characterized in that the detecting device (16) is mounted along a stretch of the feed duct (13) downstream of the intermittent valve means (); the detecting device (16) being configured to detect the passage of each charge of superabsorbent polymer material (4, 4b) in the feeding duct (13) and to send the detection signal (18) to the control and drive unit (17). 3. The machine according to claim 1 or 2, characterized in that the detecting device (16) comprises a microwave resonator (21) which at least partly faces the inside of the feeding duct (13). 4. The machine according to claim 1, characterized in that the device (16) for detecting the absorbent pad (2) is mounted along the feed line () downstream of the unit (7) for forming and applying the succession (8) of absorbent pads (2) the detecting device (16) being configured to detect the position of the discrete layer (19) of superabsorbent polymer material (4, 4b) inside the absorbent pad (2).. The machine according to claim 4, characterized in that the device (16) for detecting the absorbent pad (2) sends the position of the discrete layer (19) of superabsorbent polymer material (4, 4b) to the control and drive unit (17); the control and drive unit (17) comparing the position (22) detected by the detecting device (16) with a reference position (23) and calculating the deviation of the detected position (22) from the reference position (23); the control and drive unit (17) being configured to drive the actuator unit () to bring the valve means () into phase with the rotation of the forming drum () as a function of 6

7 11 EP B1 12 that deviation. 6. The machine according to claim 4 or, characterized in that the detecting device (16) comprises a microwave resonator (21) which at least partly faces the succession (8) of the absorbent pads (2) advancing along the feed line (). 7. The machine according to any one of claims 1 to 6, characterized in that the detecting device (16) detects at least one between the weight, density profile and weight profile parameters of the superabsorbent polymer materials (4b) defining the absorbent pad (2). 8. The machine according to claim 7, wherein the forming and application unit (7) comprises at least one system (32, 33, 34) for metering the superabsorbent polymer material (4, 4b), characterized in that it comprises a control and drive unit (17) connected to the detecting device (16); the control and drive unit (17) being configured to receive from the detecting device (16) at least one between the weight, density profile and weight profile parameters of the superabsorbent polymer materials (4, 4b) and to compare it with a respective reference parameter; the control and drive unit (17) being configured to drive the system (32, 33, 34) for metering the superabsorbent polymer material (4, 4b) as a function of the deviation of the detected parameter from the reference parameter. 9. A method for making absorbent sanitary articles which comprise an absorbent pad (2) in turn comprising at least one discrete layer (19) of superabsorbent polymer material (4, 4b); the method comprising a step of feeding at least one continuous web (6) of impermeable material along a feed line (); a step of forming and applying a succession (8) of absorbent pads (2) along the continuous web (6) by means of a forming and application unit (7); the step of forming and applying a succession (8) of absorbent pads (2) comprising a step of feeding a charge of superabsorbent polymer material (4, 4b) to a forming drum () through a feeding duct (13) comprising valve means () driven by their own actuator unit (); the method being characterized in that it comprises a step of sending a detection signal (18) indicating that the superabsorbent polymer material (4, 4b) has been detected; a step of comparing the detection signal (18) with a reference signal (19); and a step of driving the actuator unit () of the valve means () into phase with the drum () The method according to claim 9, characterized in that the detection signal (18) indicating that the superabsorbent polymer material (4, 4b) has been detected is sent when the charge of superabsorbent polymer material (4, 4b) passes in the feed duct (13) downstream of the valve means () and the reference signal (19) is the sync signal of the rotation of the drum (). 11. The method according to claim 9, characterized in that the step of sending a detection signal (18) indicating that the superabsorbent polymer material (4, 4b) has been detected comprises a step of detecting the position (22) of the discrete layer (19) of superabsorbent polymer material (4, 4b); a step of comparing the detected position (22) with a reference position (23) and a step of driving the actuator unit () of the valve means () into phase with the drum () as a function of the deviation of the detected position (22) from the reference position (23). 12. The method according to any one of claims 9 to 11, characterized in that it comprises a step of detecting at least one between the weight, density profile and weight profile parameters of the superabsorbent polymer materials (4, 4b) defining the absorbent pad (2). 13. The method according to claim 12, characterized in that it comprises a step of sending at least one between the weight, density profile and weight profile parameters of the superabsorbent polymer materials (4, 4b) to a control and drive unit (17) and a step of comparing the detected parameter with a respective reference parameter; and in that it comprises a step of driving a system (32, 33, 34) for metering the superabsorbent polymer material (4, 4b) as a function of the deviation of the detected parameter from the reference parameter. 14. The method according to claim 12 or 13, characterized in that the step of detecting at least one between the weight, density profile and weight profile parameters of the superabsorbent polymer materials (4b) occurs downstream of the unit () for forming and applying the absorbent pad (2).. The method according to claim 12 or 13, characterized in that the step of detecting at least one between the weight, density profile and weight profile parameters of the superabsorbent polymer materials (4b) occurs during the formation of the absorbent pad (2) in the unit (7) for forming and applying the succession (8) of absorbent pads (2). Patentansprüche 1. Maschine zur Herstellung saugfähiger Hygieneartikeln, die eine Saugeinlage (2) umfassen, die wiederum mindestens eine getrennte Schicht (19) an 7

8 13 EP B1 14 Superabsorber-Polymermaterial (4, 4b) umfasst; wobei die Maschine (1) eine Linie () zum Zuführen von mindestens einer durchgehenden Bahn (6) an undurchlässigem Material und mindestens eine Einheit (7) zum Formen und Anbringen einer Abfolge (8) an Saugeinlagen (2) entlang der durchgehenden Bahn (6) an undurchlässigem Material umfasst; wobei die Formungs- und Anbringungseinheit (7) eine Trommel () umfasst, um die Saugeinlage (2) zu formen, eine Leitung (13), um der Formungstrommel () eine Charge an Superabsorber-Polymermaterial (4, 4b) zuzuführen, sowie intermittierende Ventilmittel (), die entlang eines Teilstücks (T) der Zuführungsleitung (13) montiert sind und über ihre eigene Betätigungseinheit () gesteuert werden; wobei die Maschine (1) dadurch gekennzeichnet ist, dass sie eine Vorrichtung (16) zum Erfassen des Superabsorber-Polymermaterials (4, 4b), definierend die getrennte Schicht (19) der Saugeinlage (2), umfasst sowie eine Steuer- und Antriebseinheit (17), die mit der Erfassungsvorrichtung (16) verbunden ist; wobei die Erfassungsvorrichtung (16) ein Erfassungssignal (18) des Superabsorber-Polymermaterials übermittelt und die Steuer- und Antriebseinheit (17) ausgelegt ist, um das Erfassungssignal (18) zu erfassen und mit einem Referenzsignal (19) zu vergleichen; wobei die Steuer- und Antriebseinheit (17) ausgelegt ist, um die Betätigungseinheit () zu steuern, sodass die Ventilmittel () mit der Drehung der Formungstrommel () synchronisiert werden, wenn die Abweichung des Erfassungssignals (18) vom Referenzsignal (19) einen vorgegebenen Schwellenwert überschreitet. 2. Maschine nach Anspruch 1, dadurch gekennzeichnet, dass die Erfassungsvorrichtung (16) entlang eines Teilstücks der Zuführungsleitung (13) nach den intermittierenden Ventilmitteln () montiert ist; wobei die Erfassungsvorrichtung (16) ausgelegt ist, um den Durchgang einer jeden Charge an Superabsorber-Polymermaterial (4, 4b) in der Zuführungsleitung (13) zu erfassen und der Steuer- und Antriebseinheit (17) das Erfassungssignal (18) zu übermitteln. 3. Maschine nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass die Erfassungsvorrichtung (16) einen Mikrowellenresonator (21) umfasst, der mindestens teilweise der Innenseite der Zuführungsleitung (13) zugewandt ist. 4. Maschine nach Anspruch 1, dadurch gekennzeichnet, dass die Vorrichtung (16) zum Erfassen der Saugeinlage (2) entlang der Zuführungslinie () nach der Einheit (7) zum Formen und Anbringen der Abfolge (8) an Saugeinlagen (2) montiert ist, wobei die Erfassungsvorrichtung (16) ausgelegt ist, um die Position der getrennten Schicht (19) an Superabsorber-Polymermaterial (4, 4b) in der Saugeinlage (2) zu erfassen.. Maschine nach Anspruch 4, dadurch gekennzeichnet, dass die Vorrichtung (16) zum Erfassen der Saugeinlage (2) der Steuer- und Antriebseinheit (17) die Position der getrennten Schicht (19) an Superabsorber-Polymermaterial (4, 4b) übermittelt; wobei die Steuer- und Antriebseinheit (17) die von der Erfassungsvorrichtung (16) erfasste Position (22) mit einer Referenzposition (23) vergleicht und die Abweichung der erfassten Position (22) von der Referenzposition (23) berechnet, wobei die Steuer- und Antriebseinheit (17) ausgelegt ist, um die Betätigungseinheit () zu steuern, um die Ventilmittel () mit der Drehung der Formungstrommel () basierend auf dieser Abweichung zu synchronisieren. 6. Maschine nach Anspruch 4 oder, dadurch gekennzeichnet, dass die Erfassungsvorrichtung (16) einen Mikrowellenresonator (21) umfasst, der mindestens teilweise der Abfolge (8) an Saugeinlagen (2) zugewandt ist, die entlang der Zuführungslinie () vorgeschoben werden. 7. Maschine nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, dass die Erfassungsvorrichtung (16) mindestens einen der Parameter in Bezug auf Gewicht, Dichteprofil und Gewichtsprofil der Superabsorber-Polymermaterialien (4, 4b), die die Saugeinlage (2) definieren, erfasst. 8. Maschine nach Anspruch 7, wobei die Formungsund Anbringungseinheit (7) mindestens ein System (32, 33, 34) zum Dosieren des Superabsorber-Polymermaterials (4, 4b) umfasst, dadurch gekennzeichnet, dass sie eine Steuer- und Antriebseinheit (17) umfasst, die mit der Erfassungsvorrichtung (16) verbunden ist; wobei die Steuer- und Antriebseinheit (17) ausgelegt ist, um von der Erfassungsvorrichtung (16) mindestens einen der Parameter in Bezug auf Gewicht, Dichteprofil und Gewichtsprofil der Superabsorber-Polymermaterialien (4, 4b) zu erhalten und mit einem jeweiligen Referenzparameter zu vergleichen; wobei die Steuer- und Antriebseinheit (17) ausgelegt ist, um das System (32, 33, 34) zum Dosieren des Superabsorber-Polymermaterials (4, 4b) basierend auf der Abweichung des erfassten Parameters vom Referenzparameter zu steuern. 9. Verfahren zur Herstellung saugfähiger Hygieneartikeln, das eine Saugeinlage (2) umfasst, die wiederum mindestens eine getrennte Schicht (19) an Superabsorber-Polymermaterial (4, 4b) umfasst; wobei das Verfahren einen Schritt zum Zuführen von mindestens einer durchgehenden Bahn (6) an undurchlässigem Material entlang einer Zuführungslinie () umfasst, einen Schritt zum Formen und Anbringen einer Abfolge (8) an Saugeinlagen (2) entlang der 8

9 EP B1 16 durchgehenden Bahn (6) mittels einer Formungsund Anbringungseinheit (7); wobei der Schritt zum Formen und Anbringen einer Abfolge (8) an Saugeinlagen (2) einen Schritt zum Zuführen einer Charge an Superabsorber-Polymermaterial (4, 4b) zu einer Formungstrommel () über eine Zuführungsleitung (13) umfasst, umfassend Ventilmittel (), die über ihre eigene Betätigungseinheit () gesteuert werden; wobei das Verfahren dadurch gekennzeichnet ist, dass es einen Schritt zum Übermitteln eines Erfassungssignals (18) umfasst, das angibt, dass das Superabsorber-Polymermaterial (4, 4b) erfasst wurde; einen Schritt zum Vergleichen des Erfassungssignals (18) mit einem Referenzsignal (19); und einen Schritt zum Synchronisieren der Betätigungseinheit () der Ventilmittel () mit der Trommel ().. Verfahren nach Anspruch 9, dadurch gekennzeichnet, dass das Erfassungssignal (18), das angibt, dass das Superabsorber-Polymermaterial (4, 4b) erfasst wurde, übermittelt wird, wenn die Charge an Superabsorber-Polymermaterial (4, 4b) durch die Zuführungsleitung (13) nach den Ventilmitteln () geführt wird, und dadurch, dass das Referenzsignal (19) das Synchronisierungssignal der Drehung der Trommel () ist. 11. Verfahren nach Anspruch 9, dadurch gekennzeichnet, dass der Schritt zum Übermitteln des Erfassungssignals (18), das angibt, dass das Superabsorber-Polymermaterial (4, 4b) erfasst wurde, einen Schritt zum Erfassen der Position (22) der getrennten Schicht (19) an Superabsorber-Polymermaterial (4, 4b) umfasst; einen Schritt zum Vergleichen der erfassten Position (22) mit einer Referenzposition (23) und einen Schritt zum Synchronisieren der Betätigungseinheit () der Ventilmittel () mit der Trommel () basierend auf der Abweichung der erfassten Position (22) von der Referenzposition (23). 12. Verfahren nach einem der Ansprüche 9 bis 11, dadurch gekennzeichnet, dass es einen Schritt zum Erfassen von mindestens einen der Parameter in Bezug auf Gewicht, Dichteprofil und Gewichtsprofil der Superabsorber-Polymermaterialien (4, 4b), die die Saugeinlage (2) definieren, umfasst. 13. Verfahren nach Anspruch 12, dadurch gekennzeichnet, dass es einen Schritt zum Übermitteln von mindestens einem der Parameter in Bezug auf Gewicht, Dichteprofil und Gewichtsprofil der Superabsorber-Polymermaterialien (4, 4b) an eine Steuerund Antriebseinheit (17) und einen Schritt zum Vergleichen des erfassten Parameters mit einem jeweiligen Referenzparameter umfasst; sowie dadurch, dass es einen Schritt zum Steuern eines Systems (32, 33, 34) zum Dosieren des Superabsorber-Polymermaterials (4, 4b) basierend auf der Abweichung des erfassten Parameters vom Referenzparameter umfasst. 14. Verfahren nach Anspruch 12 oder 13, dadurch gekennzeichnet, dass der Schritt zum Erfassen von mindestens einem der Parameter in Bezug auf Gewicht, Dichteprofil und Gewichtsprofil der Superabsorber-Polymermaterialien (4, 4b) nach der Einheit () zum Formen und Anbringen der Saugeinlage (2) stattfindet.. Verfahren nach Anspruch 12 oder 13, dadurch gekennzeichnet, dass der Schritt zum Erfassen von mindestens einem der Parameter in Bezug auf Gewicht, Dichteprofil und Gewichtsprofil der Superabsorber-Polymermaterialien (4, 4b) während der Bildung der Saugeinlage (2) in der Einheit (7) zum Formen und Anbringen der Abfolge (8) an Saugeinlagen (2) stattfindet. Revendications 1. Machine de fabrication d articles hygiéniques absorbants comprenant un tampon absorbant (2) comprenant à son tour au moins une couche distincte (19) de matière polymère superabsorbante (4, 4b) ; la machine (1) comprenant une ligne () servant au moins à alimenter une bande continue (6) de matière imperméable et au moins une unité (7) servant à former et à appliquer une succession (8) de tampons absorbants (2) le long de la bande continue (6) de matière imperméable ; l unité de formation et d application (7) comprenant un tambour () servant à former le tampon absorbant (2), un conduit (13) servant à alimenter une dose de matière polymère superabsorbante (4, 4b) au tambour de formation () et des moyens de vanne intermittents () montés le long d une portion (T) du conduit d alimentation (13) et entraînés par sa propre unité d actionnement () ; la machine (1) étant caractérisée en ce qu elle comprend un dispositif (16) servant à détecter la matière polymère superabsorbante (4, 4b) définissant la couche distincte (19) du tampon absorbant (2) et une unité de commande et d entraînement (17) reliée au dispositif de détection (16) ; le dispositif de détection (16) envoyant un signal de détection (18) de la matière polymère superabsorbante et l unité de commande et d entraînement (17) étant configurée pour acquérir le signal de détection (18) et le comparer à un signal de référence (19) ; l unité de commande et d entraînement (17) étant configurée pour entraîner l unité d actionnement () pour mettre les moyens de vanne () en phase avec la rotation du tambour de formation () si la déviation du signal de détection (18) provenant du signal de 9

10 17 EP B1 18 référence (19) excède une valeur seuil définie. 2. Machine selon la revendication 1, caractérisée en ce que le dispositif de détection (16) est monté le long d une portion du conduit d alimentation (13) en aval des moyens de vanne intermittents () ; le dispositif de détection (16) étant configuré pour détecter le passage de chaque dose de matière polymère superabsorbante (4, 4b) dans le conduit d alimentation (13) et pour envoyer le signal de détection (18) à l unité de commande et d entraînement (17). 3. Machine selon les revendications 1 ou 2, caractérisée en ce que le moyen de détection (16) comprend un résonateur micro-ondes (21) qui au moins fait en partie face à l intérieur du conduit d alimentation (13). 4. Machine selon la revendication 1, caractérisée en ce que le dispositif (16) servant à détecter le tampon absorbant (2) est monté le long de la ligne d alimentation () en aval de l unité (7) servant à former et à appliquer la succession (8) de tampons absorbants (2), le dispositif de détection (16) étant configuré pour détecter la position de la couche distincte (19) de matière polymère superabsorbante (4, 4b) à l intérieur du tampon absorbant (2).. Machine selon la revendication 4, caractérisée en ce que le dispositif (16) servant à détecter le tampon absorbant (2) envoie la position de la couche distincte (19) de matière polymère superabsorbante (4, 4b) à l unité de commande et d entraînement (17) ; l unité de commande et d entraînement (17) comparant la position (22) détectée par le dispositif de détection (16) avec une position de référence (23) et calculant la déviation de la position détectée (22) à partir de la position de référence (23) ; l unité de commande et d entraînement (17) étant configurée pour entraîner l unité d actionnement () pour mettre les moyens de vanne () en phase avec la rotation du tambour de formation () en fonction de cette déviation. 6. Machine selon les revendications 4 ou, caractérisée en ce que le moyen de détection (16) comprend un résonateur micro-ondes (21) qui au moins fait face partiellement à la succession (8) de tampons absorbants (2) avançant le long de la ligne d alimentation (). 7. Machine selon l une quelconque des revendications de 1 à 6, caractérisée en ce que le dispositif de détection (16) détecte au moins l un des paramètres parmi le poids, le profil de densité et les paramètres de profil de poids d au moins une des matières polymères superabsorbantes (4, 4b) définissant le tampon absorbant (2) Machine selon la revendication 7, dans laquelle l unité de formation et d application (7) comprend au moins un système (32, 33, 34) pour doser la matière polymère superabsorbante (4, 4b), caractérisée en ce qu elle comprend une unité de commande et d entraînement (17) reliée au dispositif de détection (16) ; l unité de commande et d entraînement (17) étant configurée pour recevoir du dispositif de détection (16) au moins l un des paramètres parmi le poids, le profil de densité et les paramètres de profil de poids d au moins une des matières polymères superabsorbantes (4, 4b) et pour le comparer à un paramètre de référence respectif ; l unité de commande et d entraînement (17) étant configurée pour entraîner le système (32, 33, 34) pour doser la matière polymère superabsorbante respective (4, 4b) en fonction de la déviation du paramètre détecté à partir du paramètre de référence. 9. Procédé de fabrication d articles hygiéniques absorbants comprenant un tampon absorbant (2) comprenant à son tour au moins une couche distincte (19) de matière polymère superabsorbante (4, 4b) ; le procédé comprenant une étape consistant à alimenter au moins une bande continue (6) de matière imperméable le long d une ligne d alimentation () ; une étape consistant à former et à appliquer une succession (8) de tampons absorbants (2) le long de la bande continue (6) au moyen d une unité de formation et d application (7) ; l étape consistant à former et à appliquer une succession (8) de tampons absorbants (2) comprenant une étape d alimentation d une dose de matière polymère superabsorbante (4, 4b) à un tambour de formation () à travers un conduit d alimentation (13) comprenant des moyens de vanne () entraînés par leur propre unité d actionnement () ; le procédé étant caractérisé en ce qu il comprend une étape consistant à envoyer un signal de détection (18) indiquant que la matière polymère superabsorbante (4, 4b) a été détectée ; une étape consistant à comparer le signal de détection (18) avec un signal de référence (19) ; et une étape consistant à entraîner en phase l unité d actionnement () des moyens de vanne () avec le tambour ().. Procédé selon la revendication 9, caractérisé en ce que le signal de détection (18) indiquant que la matière polymère superabsorbante (4, 4b) ayant été détectée est envoyée lorsque la dose de matière polymère superabsorbante (4, 4b) passe dans le conduit d alimentation (13) en aval des moyens de vanne () et le signal de référence (19) est le signal de synchronisation de la rotation du tambour (). 11. Procédé selon la revendication 9, caractérisé en ce que l étape consistant à envoyer un signal de détection (18) indiquant que la matière polymère superab-

11 19 EP B1 sorbante (4, 4b) a été détectée comprend une étape consistant à détecter la position (22) de la couche distincte (19) de matière polymère superabsorbante (4, 4b) ; une étape consistant à comparer la position détectée (22) à une position de référence (23) et une étape consistant à entraîner l unité d actionnement () des moyens de vanne () en phase avec le tambour () en fonction de la déviation de la position détectée (22) à partir de la position de référence (23). 12. Procédé selon l une quelconque des revendications de 9 à 11, caractérisé en ce qu il comprend une étape consistant à détecter au moins l un des paramètres parmi le poids, le profil de densité et les paramètres de profil de poids d au moins une des matières polymères superabsorbantes (4, 4b) définissant le tampon absorbant (2). 13. Procédé selon la revendication 12, caractérisé en ce qu il comprend une étape consistant à envoyer au moins l un des paramètres parmi le poids, le profil de densité et les paramètres de profil de poids des matières polymères superabsorbantes (4, 4b) à une unité de commande et d entraînement (17) et une étape consistant à comparer le paramètre détecté à un paramètre de référence respectif ; et en ce qu il comprend une étape consistant à entraîner un système (32, 33, 34) destiné à doser la matière polymère superabsorbante (4, 4b) en fonction de la déviation du paramètre détecté à partir du paramètre de référence Procédé selon les revendications 12 ou 13, caractérisé en ce que l étape consistant à détecter au moins un paramètre parmi le poids, le profil de densité et les paramètres de profil de poids des matières polymères superabsorbantes (4, 4b) se déroule en aval de l unité () servant à former et à appliquer le tampon absorbant (2).. Procédé selon les revendications 12 ou 13, caractérisé en ce que l étape consistant à détecter au moins un paramètre parmi le poids, le profil de densité et les paramètres de profil de poids des matières polymères superabsorbantes (4, 4b) se déroule lors de la formation du tampon absorbant (2) dans l unité (7) servant à former et à appliquer la succession (8) de tampons absorbants (2)