Method and apparatus for feeding a production line of absorbent sanitary articles with a layer of a virgin multilayer tape

Abstract

A method for feeding a production line of absorbent sanitary articles with a layer of a virgin multilayer tape including providing a head free end of the virgin multilayer tape partially unwound from a respective virgin spool; providing a tail free end of a multilayer tape in use; applying a first connecting element on a first layer of the virgin multilayer tape and on a first layer of the multilayer tape in use at the head free end and tail free end; applying a second connecting element on a second layer of the virgin multilayer tape and on a second layer of the multilayer tape in use at the head free end and tail free end; pulling the first layer of the virgin multilayer tape in a first direction; pulling the second layer of the virgin multilayer tape in a second direction.

Claims

1. A method for feeding a production line of absorbent sanitary articles with a layer of a virgin multilayer tape, comprising: providing a head free end of said virgin multilayer tape partially unwound from a respective virgin spool; providing a tail free end of a multilayer tape in use; applying a first connecting element on a first layer of the virgin multilayer tape and on a first layer of the multilayer tape in use at said head free end and said tail free end; applying a second connecting element on a second layer of the virgin multilayer tape and on a second layer of the multilayer tape in use at said head free end and said tail free end; pulling the first layer of said virgin multilayer tape in a first direction (D1) by making the first layer of the multilayer tape in use and the first connecting element advance in the first direction (D1); pulling the second layer of said virgin multilayer tape in a second direction (D2) divergent from the first direction by making the second layer of the multilayer tape in use and the second connecting element advance in the second direction.

2. The method according to claim 1, wherein the layer to be fed to the production line is the second layer of the virgin multilayer tape, wherein each of the second layer of the virgin multilayer tape and the second layer of the multilayer tape in use comprises a main layer comprising a glue substrate, and wherein each of the first layer of the virgin multilayer tape and the first layer of the multilayer tape in use comprises a protective layer to be removed that covers the glue substrate of the main layer.

3. The method according to claim 2, wherein applying said second connecting element is performed after applying said first connecting element.

4. The method according to claim 1, wherein applying said second connecting element is performed after applying said first connecting element.

5. The method according to claim 4, comprising: moving said head free end and said tail free end after applying the first connecting element and before applying the second connecting element; wherein the second connecting element is applied while said head free end and said tail free end are moving along a feed path.

6. The method according to claim 5, wherein applying the second connecting element comprises: detecting by a sensor the first connecting element already applied; wherein applying said second connecting element is performed when the sensor detects the first connecting element.

7. The method according to claim 4, wherein applying the second connecting element comprises: detecting by a sensor the first connecting element already applied; wherein applying said second connecting element is performed when the sensor detects the first connecting element.

8. The method according to claim 1, wherein said first connecting element and the second connecting element, when applied, are not overlapped to each other.

9. The method according to claim 1, wherein applying the first connecting element comprises arranging the head free end of said virgin multilayer tape in a position adjacent to the tail free end of said multilayer tape in use without overlapping said head free end to said tail free end.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further characteristics and advantages of the present invention will become clearer from the following detailed description of a preferred embodiment thereof, made with reference to the appended drawings and provided by way of indicative and non-limiting example, in which:

(2) FIG. 1 is a schematic view of an apparatus in accordance with the present invention;

(3) FIGS. 2-7 are schematic views of details of the apparatus of FIG. 1, in respective operating configurations in accordance with the method of the present invention;

(4) FIG. 8 is a schematic plan view of two joined tapes in accordance with the method of the present invention;

(5) FIGS. 9-11 are schematic views of details of the apparatus of FIG. 1, in further operating configurations in accordance with the method of the present invention.

DETAILED DESCRIPTION

(6) In the accompanying figures, the reference numeral 100 is used to indicate an apparatus in accordance with the present invention. The apparatus 100 is configured to feed a production line 200 of absorbent sanitary article (schematically shown in FIG. 1) with a main layer 47 of a multilayer tape in use 46 and, subsequently, with a main layer 57 of a virgin multilayer tape 56.

(7) In a preferred embodiment thereof, each main layer 47, 57 comprises a main substrate made of a solid material, preferably at least partially biodegradable, for example paper, and a glue substrate that covers the main substrate.

(8) In the production line 200, not shown in detail, a plurality of semi-finished products of absorbent sanitary articles are being processed. The main layer 47 and thereafter the main layer 57 are continuously fed from the apparatus 100 to the production line 200, where they are cut into discrete sheets (not shown) of rectangular or square shape, each comprising a portion of the main substrate covered with a portion of the glue substrate.

(9) Non-limiting examples of absorbent sanitary articles made in the production line 200 are sanitary pads for women, baby diapers, diapers and pads for people suffering from incontinence and the like. Such absorbent sanitary articles (not shown) comprise an upper layer and a lower layer overlapped and joined together, between which a core of absorbent material is interposed. The lower layer is made of a non-woven fabric, preferably of biodegradable cellulose-based material.

(10) In the production line 200, one or more discrete sheets obtained by cutting the main layers 47, 57 are applied to each semi-finished product of absorbent article, so that the glue of the respective glue substrate adheres to the lower layer and remains stuck on the surface of the lower layer. The glue of each glue substrate is viscous enough to remain on the surface and not penetrate in a significant amount into the lower layer.

(11) Each main substrate is configured such that the portion of main substrate of each discrete sheet is weakly held on the lower layer of the absorbent article by the glue of the respective glue substrate and performs the function of protecting the glue. The absorbent sanitary articles are then packaged with the respective main substrates still held on the lower layer, so that they can be removed by the end consumer at the time of use of the absorbent sanitary article.

(12) Each main layer 47, 57 is stored, transported and preserved in a respective spool 45, 55. A respective multilayer tape 46, 56 is wound on each spool 45, 55. In FIG. 1, the multilayer tape 46, hereinafter referred to as multilayer tape in use, has been unwound from the spool 45, hereinafter referred to as spool in use, and made to advance along an advancement path P to feed the main layer 47 to the production line 200 and the multilayer tape 56, hereinafter referred to as virgin multilayer tape is unwound from the spool 55, hereinafter referred to as virgin spool, and made to advance along the advancement path P to feed the main layer 57 to the production line 200 upon depletion of the main layer 47.

(13) Each multilayer tape 46, 56 comprises the respective main layer 47, 57 and a respective protective layer 40, 50 overlapped to the glue substrate of the respective main layer 47, 57 to protect the glue substrate. Each protective layer 40, 50 is configured to be interposed between successive overlapped windings of the main layer 47, 57 of the respective multilayer tape 46, 56 wound on the respective spool 45, 55, so as to prevent these successive windings from sticking together due to the glue substrate.

(14) Each protective layer 40, 50 is made of a material that can adhere to the glue substrate and be easily removed leaving the glue on the respective main substrate. Each protective layer 40, 50 is configured so that it can be removed from the respective main layer 47, 57 without dragging the glue away from the glue substrate. The protective layers 40, 50 are for example made of siliconized paper. The main layer 47 and the protective layer 40 overlapped thereon form the multilayer tape 46 and are wound together on the spool 45. The main layer 57 and the protective layer 50 overlapped thereon form the multilayer tape 56 and are wound together on the spool 55.

(15) The apparatus 100 comprises a first spool support 101 and a second spool support 102 configured to interchangeably support the spools 45 and 55.

(16) In a first operating configuration of the apparatus 100, shown in FIGS. 1-3, the second spool support 102 supports the spool in use 45, whose multilayer tape in use 46 has been unwound to feed its main layer 47 to the production line 200. In this operating configuration the first spool support 101 is available for receiving the virgin spool 55 so that the virgin spool 55 is ready to replace the spool in use 45 when the latter is depleted.

(17) In a second operating configuration of the apparatus 100, shown in FIGS. 9 and 10, the first spool support 101 supports the spool in use 45 while the main layer 47 of the multilayer tape in use 46 is fed to the production line 200. In the second configuration the second spool support 102 is available for receiving the virgin spool 55, so that the virgin spool 55 is ready to replace the spool in use 45 when the latter is depleted.

(18) In this way the virgin multilayer tape 56 of the virgin spool 55 can be replaced quickly to the multilayer tape in use 46 after depletion of the multilayer tape in use 46.

(19) The apparatus 100 comprises a joining station 105, schematically shown in FIG. 1, at which the virgin multilayer tape 56 is joined to the multilayer tape in use 46.

(20) The joining station 105 comprises a first holding device 110. The first holding device 110 is configured to hold a head free end 58 of the virgin multilayer tape 56, partially unwound from the virgin spool 55 (FIG. 4). The head free end 58 of the virgin multilayer tape 56 can be positioned on the first holding device 110 manually by an operator. The first holding device 110 is preferably pneumatic and is configured to hold the head free end 58 by suction. The first holding device 110 is configured to hold the head free end 58 of the virgin multilayer tape 56 in the first configuration of the apparatus 100. The head free end 58 of the virgin multilayer tape 56 is arranged on the first holding device 110 with the main layer 57 placed against the first holding device 110 and the protective layer 50 facing away from the first holding device 110.

(21) The joining station 105 further comprises a knife 112. The knife 112 is configured to cut the multilayer tape in use 46 to obtain a tail free end 48. In the first operating configuration and in the second operating configuration of the apparatus 100, when the spool in use 45 is running out, the multilayer tape in use 46 is stopped and held under tension and the knife 112 traverses the multilayer tape in use 46 to cut it clean transversely. The cut part 49 of the multilayer tape in use 46 that remains partially wound in the spool in use 45 is disposed of.

(22) The joining station 105 further comprises a second holding device 114. The second holding device 114 is configured to hold the tail free end 48 of the multilayer tape in use 46. The second holding device 114 is adjacent to the first holding device 110. The second holding device 114 is configured to hold the tail free end 48 of the multilayer tape in use 46 cut by the knife 112. The second holding device 114 is preferably pneumatic and is configured to hold the tail free end 48 by suction. The first holding device 110 and the second holding device 114 have a common lying plane. In the first and second operating configurations, the first holding device 110 and the second holding device 114 hold the multilayer tape in use 46 while it is cut by the knife 112 and, subsequently, the second holding device 114 holds the tail free end 48 of the multilayer tape in use 46. After cutting, the tail free end 48 of the multilayer tape in use 46 is arranged on the second holding device 114 with the protective layer 40 and the main layer 47 arranged as the virgin multilayer tape 56. The main layer 47 is placed against the second holding device 114 and the protective layer 40 faces away from the second holding device 114.

(23) The joining station 105 further comprises a first applicator 116. The first applicator 116 is configured to hold a first connecting element 60 and to apply it on the protective layer 50 of the virgin multilayer tape 56 and on the protective layer 40 of the multilayer tape in use 46 at the head free end 58 and the tail free end 48. The first connecting element 60 comprises an adhesive sheet 61 having an adhesive face and a non-adhesive face. The first applicator 116 is arranged on the opposite side to the first holding device 110 and the second holding device 114 with respect to the advancement path P.

(24) The first applicator 116 is configured to hold the first connecting element 60 by suction from the side of the non-adhesive face. The first applicator 116 is movable between a rest position distal with respect to the first holding device 110 and to the second holding device 114 and an application position proximal and facing the first holding device 110 and the second holding device 114. The first applicator 116, in the respective application position, is configured to press the adhesive face of the first connecting element 60 against the first holding device 110 and the second holding device 114.

(25) In the first configuration of the apparatus 100, the first connecting element 60 is arranged on the first applicator 116 in the rest position, preferably manually by the operator. After the knife 112 has cut the multilayer tape in use 46, the tail free end 48 of the multilayer tape in use 46 is held by the second holding device 114 and the head free end 58 of the virgin multilayer tape 56 is held by the first holding device 110, the one next to the other and in a common lying plane. The first applicator 116 is moved from the rest position to the application position towards the first holding device 110 and the second holding device 114. In the application position, the adhesive face of the first connecting element 60 contacts the head free end 58 and the tail free end 48, adhering to both. The first holding device 110 and the second holding device 114 hold the tail free end 48 of the multilayer tape in use 46 and the head free end 58 of the virgin multilayer tape 56 from opposite the side to the first applicator 116 during application of the first connecting element 60. The first applicator 116 is then returned to the rest position.

(26) In the second configuration of the apparatus 100, the first connecting element 60 is preliminarily applied to the head free end 58 of the virgin multilayer tape 56 partially unwound from the virgin spool 55, preferably manually by an operator, so as to protrude from the head free end 58. The first connecting element 60 and the head free end 58 are then both arranged, already joined, on the first applicator 116 in the rest position, preferably manually by the operator. After the knife 112 has cut the multilayer tape in use 46, the tail free end 48 of the multilayer tape in use 46 is held by the second holding device 114. The first applicator 116 is moved from the rest position to the application position towards the first holding device 110 and the second holding device 114. In the application position, the adhesive face of the first connecting element 60 protruding from the head free end 58 of the virgin multilayer tape 56 contacts the tail free end 48 of the multilayer tape in use 46, adhering thereto. The first applicator 116 is then returned to the rest position. The first connecting element 60 is applied on the protective layer 50 of the virgin multilayer tape 56 and on the protective layer 40 of the multilayer tape in use 46 to join the protective layers 50, 40 of the virgin multilayer tape 56 and of the multilayer tape in use 46. In this way the multilayer tape in use 46 and the virgin multilayer tape 56 are joined together through the respective protective layers 40, 50.

(27) The joining station 105 further comprises a second applicator 118. The second applicator 118 is configured to hold a second connecting element 70 and to apply it on the main layer 57 of the virgin multilayer tape 56 and on the main layer 47 of the multilayer tape in use 46 at the head free end 58 and the tail free end 48. The second applicator 118 is arranged downstream of the first applicator 116 along the advancement path P. The second applicator 118 is further arranged on the opposite side to the first applicator 116 with respect to the advancement path P.

(28) The second connecting element 70 comprises one or more adhesive sheets 71 having an adhesive face and a non-adhesive face. The second applicator 118 is analogous to the first applicator 116. The second applicator 118 is configured to hold the second connecting element 70 by suction from the side of the non-adhesive face.

(29) The joining station 105 also comprises an abutment element 120. The abutment element 120 is arranged on the opposite side to the second applicator 118 with respect to the advancement path P. The second applicator 118 is movable between a rest position distal with respect to the abutment element 120 and an application position proximal and facing the abutment element 120. The second applicator 118, in the respective application position, is configured to press the adhesive face of the second connecting element 70 against the abutment element 120.

(30) The joining station 105 also comprises a sensor 122. The sensor 122 is arranged along the advancement path P between the first applicator 116 and the second applicator 118. The sensor 122 is arranged downstream of the first applicator 116 and upstream of the second applicator 118 with respect to the advancement path P. The sensor 122 is configured to detect the first connecting element 60. Preferably, the sensor 122 is of the optical type, for example a photocell, and faces toward the advancement path P.

(31) In both the first configuration and the second configuration of the apparatus 100, the second connecting element 70 is arranged on the second applicator 118 in a rest position, preferably manually by the operator.

(32) The second connecting element 70 is applied on the second applicator 118 such that it is not overlapped to the first connecting element 60 when applied. For example, as shown in FIG. 9, the first connecting element 60 may comprise a single adhesive sheet 61 positioned on the first applicator 116 so as to be applied at a central portion of the head free end 58 and tail free end 48 and the second connecting element 70 may comprise two adhesive sheets 71 positioned on the second applicator 118 so as to be applied at opposite side portions of the head free end 58 and of the tail free end 48, to the sides of the first connecting element 60, or vice versa. In a further example that is non shown, the first connecting element 60 may comprise a single adhesive sheet positioned on the first applicator 116 so as to be applied at a side portion of the head free end 58 and tail free end 48 and the second connecting element 70 may comprise a single sheet positioned on the second applicator 118 so as to be applied at an opposite side portion of the head free end 58 and of the tail free end 48.

(33) The second applicator 118 is controlled by signals received by the sensor 122, so as to apply the second connecting element 70 on the head free end 58 and tail free end 48 at the first connecting element 60. After the first applicator 116 has applied the first connecting element 60, the multilayer tape in use 46 and the virgin multilayer tape 56 are made to advance along the advancement path P joined by only the first connecting element 60 at the respective head free end 58 and tail free end 48. The second connecting element 70 is applied subsequently to the first connecting element 60, while the head free end 58 and tail free end 48 are moving along the advancement path P. The sensor 122 detects the first connecting element 60 and controls the movement of the second applicator 118 from the rest position to the application position. The movement of the second applicator 118 from the moment in which the sensor 122 detects the first connecting element 60 can be substantially instantaneous or delayed by a pre-established time so that the second connecting element 70 is applied at the first connecting element 60. In the application position, the adhesive face of the second connecting element 70 contacts the head free end 58 and the tail free end 48, adhering to both. The abutment element 120 holds the tail free end 48 of the multilayer tape in use 46 and the head free end 58 of the virgin multilayer tape 56 on the side opposite to the second applicator 118 during application of the first connecting element 60. The second applicator 118 is then returned to the rest position.

(34) The second connecting element 70 is applied on the main layer 57 of the virgin multilayer tape 56 and on the main layer 47 of the multilayer tape in use 46 to join the main layers 57, 47 of the virgin multilayer tape 56 and of the multilayer tape in use 46. In this way, the second connecting element 70 joins the multilayer virgin tape 56 to the multilayer tape in use 46 on the opposite side to the first connecting element 60 and through the respective main layers 57, 47.

(35) A separation station 130, shown in FIGS. 1 and 7, is arranged downstream of the joining station 105 along the advancement path P. In the separation station 130 the protective layer 40 is separated from the main layer 47.

(36) A first pulling member 150 is arranged at the separation station 130. The first pulling member 150 is configured to move the protective layer 40 of the multilayer tape in use 46 and the protective layer 50 of the virgin multilayer tape 56 in a first direction D1. In the accompanying figures, the first pulling member 150 is schematically represented as a roller.

(37) A second pulling member 155 is arranged at the separation station 130. The second pulling member 155 is configured to move the main layer 47 of the multilayer tape in use 46 and the main layer 57 of the virgin multilayer tape 56 in a second direction D2. The second direction D2 is divergent from the first direction D1. In the accompanying figures the second pulling member 155 is schematically represented as a roller.

(38) After the application of the first connecting element 60 and of the second connecting element 70, the first pulling member 150 and the second pulling member 155 move the protective layer 40 and the main layer 47 of the multilayer tape in use 46 respectively in the first direction D1 and in the second direction D2. The tail free end 48 of the multilayer tape in use 46, the first connecting element 60, the second connecting element 70, and the head free end 58 of the multilayer tape in use 46 are dragged along the advancement path P towards the separation station 130.

(39) When the tail free end 48 of the multilayer tape in use 46 arrives at the separation station 130, the first connecting element 60 is dragged in the first direction D1 by the protective layer 40 of the multilayer tape in use 46. The first connecting element 60 in turn drags in the first direction D1 the protective layer 50 of the virgin multilayer tape 56. At the same time, the second connecting element 70 is dragged in the second direction D2 by the main layer 47 of the multilayer tape in use 46. The second connecting element 70 in turn drags in the second direction D2 the main layer 57 of the virgin multilayer tape 56.

(40) In the embodiment shown in the figures, the protective layer 40 of the multilayer tape in use 46 and the protective layer 50 of the virgin multilayer tape 56, after the separation of the main layers 40 and 50, are conveyed to a disposal device 140. The main layer 47 of the multilayer tape in use 46 and the main layer 57 of the virgin multilayer tape 56, after the separation of the protective layers 40 and 50, are conveyed to the production line 200.

(41) In the disposal device 140, the protective layer is disposed of, e.g. destroyed.

(42) The main layer 57 of the virgin multilayer tape 56 is fed to the production line 200. The virgin multilayer tape 56 thus becomes the multilayer tape in use 46 and the virgin spool 55 from which it is unwound becomes the spool in use 45. When such a spool is running out, the method described above may be repeated. The method is repeated by alternating at each iteration the first operating configuration and the second operating configuration of the apparatus 100 described above.

(43) Obviously, a person skilled in the art, in order to satisfy specific and contingent needs, can make numerous modifications and changes to the invention described above while remaining within the scope of protection defined by the following claims.