Method and apparatus for folding absorbent sanitary products

Abstract

To provide a method and apparatus for folding absorbent sanitary articles.SOLUTION: In a method for folding absorbent sanitary articles, multiple absorbent sanitary articles advancing at a first speed (V1) are alternately routed towards at least two folding lines (18, 20), are slowed down to a second speed (V2) that is less than the first speed (V1), are folded while advancing at the second speed (V2), and are fed aligned with each other in a common outlet array (58).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to packaging for absorbent sanitary products.

[0002] In particular, the invention refers to folding absorbent sanitary products around one or two transverse fold lines at the end of the production line, upstream of the packaging machine.

[0003] The present invention has been developed in particular for its application in the field of feminine sanitary napkins, for example panty liners, light incontinence napkins, etc.

[0004] However, the invention is not limited to this particular field and can be used in all cases where it is necessary to fold an absorbent sanitary product around one or two transverse fold lines. [Background technology]

[0005] Some absorbent sanitary products, such as feminine sanitary napkins, are often individually packaged in their own pouch-like packaging.

[0006] Individual packaging of absorbent sanitary products may be carried out by enclosing each absorbent sanitary product between two flexible sheets, which are placed one on top of the other in a sandwich fashion and joined together at their edges by adhesive, enclosing each absorbent sanitary product.

[0007] Also known is a solution in which each absorbent sanitary product is enclosed in a casing made from a single sheet of flexible material that is folded to form two flaps joined together at their edges by gluing.

[0008] The wrapper may be made from a plastic material, for example polyethylene, or from a sheet of paper material.

[0009] Before packaging, absorbent sanitary products are often folded in two or three. This folding is performed by folding the absorbent sanitary product about one or two transverse axes relative to the longitudinal axis of the product. Feminine sanitary napkins are often folded into three overlapping portions.

[0010] Figure 18 of EP-A-2157952 describes an apparatus for folding disposable absorbent articles in thirds, in which the absorbent articles are inserted between two opposing belts by a folding blade that impinges laterally against the article along a fold line. In a first folding assembly, the sanitary articles are folded over approximately one-third of their length. The partially folded articles are passed to a second folding assembly which folds the remaining portion to produce a three-folded sanitary article made of three overlapping layers.

[0011] In modern machines for manufacturing absorbent sanitary products, the product moves at very high speeds: for example, if the absorbent sanitary product has a length in the machine direction of 300 mm and the machine is operated at a rate of 1000 pieces per minute, the product will travel at a speed of 300 m / min and each of the folding blades will impact the sanitary product at a frequency of 1000 times per minute.

[0012] Due to the high linear speed of the absorbent sanitary product when struck by the folding blade, there is a risk of damage to the product, the frequency of damage to the absorbent sanitary product increasing the faster the speed at which the product is advanced.

[0013] Typically, the speed of the folding machine is the bottleneck that limits the speed of the packaging machine: in practice, even if the packaging machine can run at a faster speed, their speed is limited by the maximum speed of the folding device. Summary of the Invention

[0014] SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for folding absorbent sanitary products that overcomes the problems of the prior art.

[0015] According to the present invention, this object is achieved by a method and a device for folding absorbent sanitary products having the features forming the subject matter of claims 1 and 7.

[0016] Preferred embodiments form the subject matter of the dependent claims.

[0017] The claims form an essential part of the disclosure provided herein regarding the invention. [Brief explanation of the drawings]

[0018] The invention will now be described in detail with reference to the accompanying drawings, given by way of non-limiting example only, in which: [Figure 1] 1 is a schematic side view of one embodiment of an apparatus for folding absorbent sanitary products according to the present invention; [Figure 2] 2 is an enlarged scale view of the fold indicated by arrow II in FIG. 1; [Figure 3] 1(a), (b), (c), (d) and (e) are schematic diagrams illustrating one embodiment of a method for folding an absorbent sanitary product according to the present invention.

[0019] It will be understood that the accompanying drawings are schematic and that in certain figures some components may not be shown to aid in understanding the figures. It will be understood that the various figures may not be drawn to scale. DETAILED DESCRIPTION OF THE INVENTION

[0020] Referring to Figure 1, the numeral 10 indicates an apparatus for folding absorbent sanitary products. The apparatus 10 may be located at the discharge of a manufacturing machine, upstream of a packaging machine (not shown).

[0021] 1 and 3(a), the apparatus 10 includes an inlet conveyor 12 configured to advance an inlet array 14 along a machine direction MD at a first velocity V1.

[0022] The inlet array 14 is formed by a plurality of aligned absorbent sanitary products 16. The absorbent sanitary products 16 forming the inlet array 14 are as they exit a manufacturing machine. In particular, the absorbent sanitary products 16 in the inlet array 14 are laid out in a flat shape and are not packaged.

[0023] The absorbent sanitary products 16 in the inlet array 14 are aligned with one another and have their respective longitudinal axes parallel to the machine direction MD.

[0024] In the inlet array 14, the absorbent sanitary products 16 may be substantially in contact with one another such that the pitch between the absorbent sanitary products 16 is substantially equal to their length.

[0025] The device 10 includes at least two fold lines 18, 20 configured to fold the absorbent sanitary product 16 about respective transverse axes relative to the longitudinal axis of the absorbent sanitary product 16.

[0026] In the example shown in the figures, the device 10 comprises two folding lines 18, 20. In contemplated embodiments, the device 10 may comprise three or more folding lines.

[0027] Each of the fold lines 18, 20 can be configured to fold the absorbent sanitary product 16 in two or three. When folded in two, the absorbent sanitary product 16 is folded about a central horizontal axis and has two flaps that overlap each other after folding. When folded in three, the absorbent sanitary product 16 is folded about two horizontal axes located approximately 1 / 3 and 2 / 3 of the length of the absorbent sanitary product 16 and has three flaps that overlap each other after folding.

[0028] 2, each folding line 18, 20 has a belt folding device 22. In the example shown, the belt folding device 22 is configured to fold each absorbent sanitary product 16 in thirds.

[0029] The belt folding device 22 includes a first belt 24, a second belt 26, and a third belt 28. The first belt 24 and the second belt 26 have respective straight sections facing each other that define a first folding channel 30. The first belt 24 and the third belt 28 have respective straight sections facing each other that define a second folding channel 32.

[0030] The belt folding device 22 comprises a first inserter device 34 configured to insert the continuous absorbent sanitary product 16 into the first folding channel 30 and a second inserter device 36 configured to insert the continuous absorbent sanitary product 16 into the second folding channel 32. The first and second inserter devices 34, 36 may have rotating folding blades 38, 40, respectively. The absorbent sanitary product 16 moves along the belt folding device 22 in the direction indicated by the arrows and is laterally folded once in the first folding channel 30 and once in the second folding channel 32.

[0031] Each of the folding lines 18, 20 is provided with a respective slowing down device 42 located upstream of the respective belt folding device 22 and configured to slow down the absorbent sanitary product 16 supplied to the belt folding device 22 at a second speed V2 that is less than the first speed V1.

[0032] In this way, at each belt folding device 22, the absorbent sanitary product 16 is folded as it travels at a speed V2 that is less than the speed V1 at which the absorbent sanitary product 16 exits the manufacturing machine.

[0033] The second velocity V2 may be equal to V1 / n, where n is the number of fold lines 18, 20.

[0034] The slowing down device 42 may be a rotary re-pitching device equipped with a plurality of gripping elements 44 that can rotate independently of one another about a common axis. Each of the gripping elements 44 picks up, for example by suction, an absorbent sanitary product 16 traveling at a first speed V1 and releases it at a second speed V2 into the belt folding device 22.

[0035] The apparatus 10 comprises a directing device 46 configured to direct the absorbent sanitary products 16 coming from the inlet array 14 alternately towards at least two folding lines 18,20.

[0036] In the case where the apparatus 10 has two folding lines 18, 20, as in the example shown, the directing device 46 directs the absorbent sanitary products 16 towards the first folding line 18 and the immediately succeeding absorbent sanitary products 16 towards the second folding line 20, etc., so that each folding line 18 receives half of the absorbent sanitary products 16 from the inlet array 14.

[0037] In the case where the apparatus 10 has n folding lines, the directing device 46 directs one absorbent sanitary product 16 out of every n to each folding line, so that each folding line receives 1 / n of the absorbent sanitary products 16 coming from the inlet array 14.

[0038] The directing device 46 may comprise a belt having branches 48 that hold the absorbent sanitary products 16 by suction, and a transfer wheel 50 provided with one or more suction sectors 52 that alternately transfer the absorbent sanitary products 16 towards the first folding line 18. The absorbent sanitary articles 16 that are not picked up by the transfer wheel 50 are directed towards the second folding line 20.

[0039] The folding lines 18 , 20 include respective outlet conveyors 54 , 56 that receive the folded absorbent sanitary products 16 from the respective belt folding devices 22 and deliver the folded absorbent sanitary products 16 to a common outlet array 58 .

[0040] The three-fold process requires that two successive folds are performed on each absorbent sanitary product 16. This can introduce variability in both the dimensions of the folded absorbent sanitary product 16 in the machine direction MD and the position in the machine direction MD of the folded absorbent sanitary product 16. This variability must be addressed and controlled to allow correct phasing of the products coming from the two folding lines 18, 20 to obtain a discontinuous chain of folded absorbent sanitary products 16.

[0041] To achieve this, at least one of the outlet conveyors 54, 56 may be configured to selectively vary the speed of the individual folded absorbent sanitary products 16. An exemplary device that allows for adjustment of the speed of the individual folded absorbent sanitary products 16 is called a "smart belt."

[0042] During the start-up step of the production machine (acceleration ramp), the folded absorbent sanitary products 16 must be discarded. For this purpose, one or both of the folding lines 18, 20 may be equipped with a rejection system. The rejection system may be located in the slowdown device 42 or in the belt folding device 22.

[0043] Referring to Figures 3(a), (b), (c), (d) and (e), the method of operation of the device 10 is as follows.

[0044] In a first step, shown in Figure 3(a), the method involves forming an inlet array 14 formed by a plurality of absorbent sanitary products 16 aligned with one another.

[0045] The absorbent sanitary products 16 forming the inlet array 14, in an unfolded and unwrapped state, are advanced at a first speed V1 along the machine direction MD.

[0046] Next, as shown diagrammatically in Figure 3(b), the absorbent sanitary products 16 coming from the inlet array 14 are directed alternately towards at least two folding lines 18, 20. In Figure 3(b) and in the subsequent figures, the absorbent sanitary products 16 are shown in both plan and side views.

[0047] Thereafter, as shown schematically in FIG. 3(c), at each of the folding lines 18, 20, the speed of the absorbent sanitary product 16 is slowed to a second speed V2 that is less than the first speed V1.

[0048] At each folding line 18, 20, the absorbent sanitary product may be slowed down to a second speed V2 by a respective rotary re-pitching device 42.

[0049] The decrease in speed proportionally decreases the pitch between the absorbent sanitary products 16. For example, if speed V2 is half of speed V1, then the pitch between the movable absorbent sanitary products 16 at speed V2 is equal to half the pitch between the same absorbent sanitary products 16 at speed V1.

[0050] In a contemplated embodiment, the absorbent sanitary product 16 may travel at different speeds along the folding lines 18, 20.

[0051] Next, as shown schematically in Figure 3(d), at each of the folding lines 18, 20, the absorbent sanitary products 16 are folded about their respective transverse axes while traveling at a second speed V2. As already explained above, at each of the folding lines, the absorbent sanitary products 16 may be folded by inserting them into the folding channels 30, 32 formed between the parallel branches of the two belts 24, 26, 28. The absorbent sanitary products 16 may be inserted into the folding channels 30, 32 by rotating the folding blades 38, 40.

[0052] At each folding line 18,20, the folded absorbent sanitary products 16 exiting the respective belt folding device 22 are picked up by a respective discharge conveyor 54,56 which delivers the folded absorbent products 16 to a common discharge array 58.

[0053] In the common outlet array 58, the absorbent sanitary products 16 coming from the fold lines 18, 20 are aligned with each other in a single line.

[0054] As shown schematically in Figure 3(e), the folding lines 18, 20 supply each folded absorbent product 16 to the common outlet array 58 in phase with one another so that the folded absorbent products 16 coming from the folding lines 18, 20 alternate with one another in the common outlet array 58.

[0055] In the case where two folding lines 18, 20 are provided, each folded absorbent sanitary product 16 coming from one folding line 18, 20 is placed between two folded absorbent sanitary products 16 coming from the other folding line 18, 20.

[0056] In prior art folding devices with a single folding line, the three-fold process creates gaps in the outlet array between successive folded absorbent sanitary products. These spaced-apart folded absorbent sanitary products are placed on a successive wrapping sheet, which can have unnecessary excess packaging material in the open spaces between successive products. In prior art, to avoid this problem, it is necessary to move the folded absorbent sanitary products closer together, which slows them down in the outlet array.

[0057] In the solution according to the invention, in the common outlet array 58, the empty spaces between the folded absorbent sanitary products 16 coming from one of the folding lines 18, 20 can be filled by the folded absorbent sanitary products 16 coming from the other folding line 18, 20.

[0058] In this way, the folded absorbent sanitary products 16 are placed close to each other in the common outlet array 58. This avoids unnecessary empty spaces between the folded absorbent sanitary products 16. Therefore, it is possible to maintain the same velocity V2 in the common outlet array 58 as the folded absorbent sanitary products 16 have at the outlets of the folding lines 18, 20.

[0059] The folded absorbent sanitary products 16 obtained in accordance with the present invention may be packaged individually or in groups.

[0060] The outlet conveyors 54 , 56 that receive the folded absorbent sanitary products 16 from the respective belt holders 22 may be configured to selectively vary the speed of the individual folded absorbent products 16 .

[0061] The solution according to the invention allows the folding of the absorbent sanitary product to be carried out at a slower speed (e.g. half) compared to the speed at which the absorbent sanitary product exits the manufacturing machine, which allows a significant reduction in the risk of damage to the absorbent sanitary product.

[0062] Of course, without prejudice to the principles of the invention, the details of construction and the embodiment may be varied widely with respect to the embodiments described and illustrated, without thereby departing from the scope of the invention as defined by the claims. (Other possible items) (Item 1) A method for folding an absorbent sanitary product (16), comprising: providing an inlet array (14) formed by a plurality of absorbent sanitary products (16), wherein in said inlet array (14), said absorbent sanitary products (16) are unpackaged and travelling at a first speed (V1) along a machine direction (MD); directing the absorbent sanitary products (16) coming from the inlet array (14) towards at least two folding lines (18, 20); slowing the absorbent sanitary product (16) along each of the at least two folding lines (18, 20) to a respective second speed (V2) that is less than the first speed (V1); folding the absorbent sanitary product (16) about a respective transverse axis at each of the at least two folding lines (18, 20) while the absorbent sanitary product (16) travels at the respective second speed (V2); and feeding the aligned, folded absorbent sanitary products (16) together in a common outlet array (58); A method comprising: (Item 2) 2. The method according to item 1, wherein the absorbent sanitary product (16) travels along the at least two folding lines (18, 20) at different speeds. (Item 3) 3. The method according to claim 1 or 2, wherein the at least two folding lines (18, 20) feed the folded absorbent sanitary products (16) in synchronism with one another in the machine direction (MD) towards the common outlet array (58) such that the folded absorbent sanitary products (16) coming from one folding line (18, 20) alternate in the common outlet array (58) with folded absorbent sanitary products (16) coming from another folding line (18, 20). (Item 4) 4. The method according to any one of items 1 to 3, wherein in each of the at least two folding lines (18, 20), the absorbent sanitary products (16) are slowed down to a respective second speed (V2) by a respective rotary re-pitching device (42). (Item 5) 5. The method according to any one of items 1 to 4, wherein in each of the at least two folding lines (18, 20), the absorbent sanitary products (16) are folded by inserting them into folding channels (30, 32) formed between parallel branches of two belts (24, 26, 28). (Item 6) 6. The method according to any one of items 1 to 5, wherein the speed of the individual folded absorbent sanitary products (16) at the outlet of each folding line (18, 20) is selectively controlled before feeding the individual folded absorbent products (16) into a common outlet array (58). (Item 7) 1. An apparatus for folding absorbent sanitary products, comprising: an inlet conveyor (12) configured to advance an inlet array (14) formed by a plurality of absorbent sanitary products (16) along a machine direction (MD) at a first speed (V1); at least two folding lines (18, 20) each having a slowing device (42) configured to slow down the absorbent sanitary product (16) to a respective second speed (V2) that is less than the first speed (V1), wherein the at least two folding lines (18, 20) are configured to fold the absorbent sanitary product (16) about a respective transverse axis while the absorbent sanitary product (16) travels at the respective second speed (V2); a directing device (46) configured to direct the absorbent sanitary products (16) coming from the inlet array (14) towards the at least two folding lines (18, 20); Equipped with The at least two folding lines (18, 20) are configured to supply the folded absorbent sanitary products (16) aligned with one another in a common outlet array (58). (Item 8) 8. The apparatus according to item 7, wherein the at least two folding lines are configured to supply the folded absorbent sanitary products (16) in sync with one another in the machine direction (MD) to the common outlet array (58) such that the folded absorbent sanitary products (16) coming from one folding line (18, 20) alternate in the common outlet array (58) with folded absorbent sanitary products (16) coming from another folding line (18, 20). (Item 9) Item 9. The device according to item 7 or 8, wherein each of the at least two folding lines (18, 20) comprises a rotary re-pitching device (18) configured to slow down the absorbent sanitary product to a respective second speed (V2). (Item 10) 10. The apparatus according to any one of items 7 to 9, wherein the folding lines (18, 20) have respective outlet conveyors (54, 56) configured to selectively vary the speed of the individual folded absorbent sanitary products (16) fed to the common outlet array (58).

Claims

1. 1. A method for folding an absorbent sanitary product, comprising: providing an inlet array formed by a plurality of absorbent sanitary products, wherein the absorbent sanitary products in the inlet array are unpackaged and travel at a first speed along a machine direction; directing the absorbent sanitary products coming from the inlet array towards at least two folding lines; slowing the absorbent sanitary product along each of the at least two folding lines to a respective second speed that is less than the first speed; folding the absorbent sanitary product about a respective transverse axis at each of the at least two folding lines while the absorbent sanitary product is traveling at the respective second speed; and feeding the aligned, folded absorbent sanitary products together in a common outlet array; Equipped with wherein the at least two folding lines feed their respective folded absorbent sanitary products in sync with one another in the machine direction towards the common outlet array such that the folded absorbent products from one folding line alternate in the common outlet array with folded absorbent products from another folding line.

2. 10. The method of claim 1, wherein the absorbent sanitary product advances at different speeds along the at least two folding lines.

3. 10. The method of claim 1, wherein at each of the at least two folding lines, the absorbent sanitary product is slowed to a respective second speed by a respective rotary re-pitching device.

4. 10. The method of claim 1, wherein in each of the at least two folding lines, the absorbent sanitary products are folded by inserting them into a folding channel formed between parallel branches of two belts.

5. 5. A method according to any one of claims 1 to 4, wherein the speed of the individual folded absorbent products at the outlet of each folding line is selectively controlled before feeding the individual folded absorbent products into a common outlet array.

6. 1. An apparatus for folding absorbent sanitary products, comprising: an inlet conveyor configured to advance an inlet array formed by a plurality of absorbent sanitary products along a machine direction at a first speed; at least two folding lines each having a slowing device configured to slow the absorbent sanitary product to a respective second speed that is less than the first speed, wherein the at least two folding lines are configured to fold the absorbent sanitary product about a respective transverse axis while the absorbent sanitary product is traveling at the respective second speed; a directing device configured to direct the absorbent sanitary products coming from the inlet array towards the at least two folding lines; the at least two folding lines are configured to be synchronized with one another in the machine direction to supply the folded absorbent sanitary products aligned with one another in a common outlet array; wherein the at least two folding lines are configured to supply respective folded absorbent sanitary products to the common outlet array such that the folded absorbent products from one folding line alternate in the common outlet array with folded absorbent products from another folding line.

7. 7. The apparatus of claim 6, wherein each of the at least two folding lines includes a rotary re-pitching device configured to slow the absorbent sanitary product to a respective second speed.

8. 8. An apparatus according to claim 6 or 7, wherein the folding line has respective outlet conveyors configured to selectively vary the speed of individual folded absorbent sanitary products fed to the common outlet array.

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