Apparatus for processing a continuous moving web and a machine comprising such an apparatus

Abstract

To provide a device for processing a moving continuous web.SOLUTION: A device for processing a moving continuous web has a tool holder roller (12), an anvil roller (16), and a control device (40) constituted so as to rotate the tool holder roller (12) and the anvil roller (16) around rotation axes (14, 18) under at lest one first operation condition and one second operation condition, and thereby changes the format of the device using selection through software.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates generally to processing a continuous, moving web.

[0002] More specifically, the present invention relates to an apparatus that can be used to perform operations such as cutting, welding, embossing, perforating, etc. on a continuous, moving web, such as a composite web comprising one or more nonwoven layers.

[0003] The present invention has been particularly developed for its application to the production of absorbent sanitary articles such as diapers, diaper pants, absorbent articles for incontinent adults, etc., but is not limited to this particular field.

[0004] According to another aspect, the invention relates to a machine comprising an apparatus for treating a continuous moving web. [Background technology]

[0005] To produce absorbent sanitary products, it is often necessary to subject a continuous, moving web, such as a continuous composite web comprising a plurality of elastic yarns encapsulated between one or more nonwoven layers, to various types of processing. Processing operations can include, for example, cutting, welding, embossing, perforating, etc.

[0006] These operations are usually carried out using a device comprising an anvil roller and a tool holder roller on which tools such as cutting blades, welding elements, embossing elements, etc. are arranged depending on the processing operation to be carried out.

[0007] Rotary machines for treating a continuous moving web are configured to operate on a web corresponding to a particular type of absorbent sanitary product.

[0008] When the type of absorbent sanitary product produced on the same line is changed, the width of the operations that must be performed on the continuous web used to produce the absorbent sanitary product often also changes.

[0009] Typically, when the format of an absorbent sanitary product is changed, the rotary tools that perform operations such as cutting, welding, embossing, etc. must be changed in order to adapt the width of the tools to the new size of the product to be produced.

[0010] The solution currently employed to effect a format change is to completely or partially replace the rotating unit.

[0011] A change of type is one of the most complex and time-consuming operations, as it requires disengaging the unit's rotary shaft transmissions, pneumatic connections and mechanical fasteners, especially in hard-to-reach places.

[0012] Furthermore, removal of the units requires that there be access space within the line for lifting equipment such as forklift trucks, which significantly limits the availability of space in front of the machine.

[0013] In some cases, it may be necessary to replace only the tool holder roller of the machine, which again requires very delicate (micron-scale) adjustment movements that can risk damaging the tool. Summary of the Invention

[0014] The object of the present invention is to provide an apparatus for processing a continuous moving web, which overcomes the problems of the prior art. According to the present invention, this object is achieved by an apparatus having the features of claim 1.

[0015] According to another aspect, the invention relates to a machine according to claim 10.

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

[0017] The claims form an integral 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 purely as non-limiting examples, in which: [Figure 1] 1 is a schematic front view of a first embodiment of a device according to the invention; [Figure 2] FIG. 2 is a schematic side view according to arrow II in FIG. [Figure 3] FIG. 2 is a schematic front view of a second embodiment of the device according to the invention. [Figure 4] FIG. 4 is a schematic side view according to arrow IV in FIG. 2. [Figure 5] 1A and 1B are schematic plan views of two continuous webs processed by an apparatus according to the invention, respectively in first and second operating conditions; [Figure 6] 1A and 1B are schematic plan views of two continuous webs processed by an apparatus according to the invention, respectively in first and second operating conditions; DETAILED DESCRIPTION OF THE INVENTION

[0019] 1-4, the numeral 10 designates an apparatus for treating a continuous moving web.

[0020] The apparatus 10 includes a tool holder roller 12 rotatable about a first axis of rotation 14 and an anvil roller 16 rotatable about a second axis of rotation 18 parallel to the first axis of rotation 14 .

[0021] The tool holder roller 12 holds at least one first tool 20 and at least one second tool 22 angularly spaced apart from one another. Generally, the tool holder roller 12 can hold a generic number of tools equal to or greater than two. In the example shown in the figures, the tool holder roller 12 holds a first tool 20, a second tool 22, and a third tool 24.

[0022] In the following, reference will be made by way of example to the case where the tool holder roller 12 holds a first tool 20 and a second tool 22, but it should be understood that what is described applies equally to the case where the tool holder roller 12 holds a general number of tools equal to or greater than two.

[0023] The first tool 20 and the second tool 22 may be configured to perform an operation selected from cutting, welding, embossing, laminating, and punching.

[0024] The first tool 20 and the second tool 22 have different geometric characteristics. Specifically, the first tool 20 and the second tool 22 may have different lengths L1 and L2, respectively.

[0025] The first tool 20 and the second tool 22 may have active surfaces configured to perform different machining operations, such as machining the same type but different patterns, or different machining operations, such as welding, embossing, etc.

[0026] In a possible embodiment, the first tool 20 and the second tool 22 project radially from the outer surface 26 of the tool holder roller.

[0027] The anvil roller 16 carries at least one anvil element 28 .

[0028] 1 and 2, the anvil roller 16 carries a single anvil element 28. In this case, as described below, the first tool 20, the second tool 22, and any additional tools 24 are intended to cooperate with the same anvil element 28. The single anvil element 28 has a width L3 that is greater than the maximum width of the tools 20, 22, and 24.

[0029] 3 and 4, the anvil roller 16 carries a plurality of anvil elements 28, 30, 32 angularly spaced apart from one another. In this case, as described below, a first tool 20, a second tool 22, and any additional tools 24 are intended to cooperate with each anvil element 28, 30, 32. In this case, each tool 20, 22, 24 can be set with a corresponding anvil element 28, 30, 32.

[0030] Each of the anvil elements 28 , 30 , 32 may project radially from an outer surface 34 of the anvil roller 16 .

[0031] The tool holder roller 12 and the anvil roller 16 are driven by respective electric motors 36 , 38 that are controlled by a control device 40 .

[0032] The control device 40 is configured to rotate the tool holder roller 12 and the anvil roller 16 about their respective rotation axes 14, 18 in at least one first and one second operating condition. The number of operating conditions may be equal to the number of different tools 20, 22, 24 provided on the tool holder roller 12.

[0033] In a first operating condition, the first tool 20 of the tool holder roller 12 is in phase with the single anvil element 28 or each anvil element 28, 30, 32 and periodically cooperates with the single anvil element 28 or each anvil element 28, 30, 32 during operation to perform a working operation on the continuously moving web. In the first operating condition, the second tool 22 and any additional tools 24 are out of phase with the single anvil element 28 or with the multiple anvil elements 28, 30, 32 and do not cooperate with any of the anvil elements 28, 30, 32 during operation.

[0034] In the second operating condition, the second tool 22 of the tool holder roller 12 is in phase with the single anvil element 28 or each anvil element 28, 30, 32 and periodically cooperates with the single anvil element 28 or each anvil element 28, 30, 32 during operation to perform a working operation on the continuously moving web. In the second operating condition, the first tool 20 and any additional tools 24 are out of phase with the single anvil element 28 or with the multiple anvil elements 28, 30, 32 and do not cooperate with any of the anvil elements 28, 30, 32 during operation.

[0035] Thus, the device 10 can operate in a variety of operating conditions, but only one type of tool can operate in each operating condition, and the device 10 can switch from one operating condition to another using software selection.

[0036] Transitioning from one operating condition to another provides the possibility of changing the geometry of the process being performed on the continuously moving web, and corresponds to a change in the type of apparatus 10.

[0037] 5 and 6 show two continuous webs 42, 44 processed by the apparatus 10 at first and second operating conditions, respectively. In the example shown, the continuous webs 42, 44 are elastic bands comprising a plurality of longitudinal elastic yarns 46, 48 encapsulated between two nonwoven layers. The longitudinal elastic yarns 46, 48 are attached between the two continuous webs 42, 44 by discontinuously applied adhesive. Lines 54 and 56 define windows where no adhesive is applied and where the longitudinal elastic yarns 46, 48 are not attached between the two continuous webs 42, 44.

[0038] In the example shown, the continuous webs 42, 44 are subjected to a cutting action in the apparatus 10 to transversely cut the longitudinal elastic yarns 46, 48 at regular intervals. In Figures 5 and 6, the transverse cuts are indicated at 50 and 52 and have widths L1 and L2, respectively. After the transverse cuts 50, 52, the portions of the longitudinal elastic yarns 46, 48 that are not attached to the two continuous webs 42, 44 each shrink to a line 56.

[0039] In a first operating condition, the apparatus 10 is configured to operate with a first tool 20 having a width L1, which periodically cooperates with one of the anvil elements 28, 30, 32 to make a first cut 50 in the first moving continuous web 42 with a width L1 and a pitch P1.

[0040] In a second operating condition, the apparatus 10 is configured to operate with a second tool 22 having a width L2, which periodically cooperates with one of the anvil elements 28, 30, 32 to make second cuts 52 in the second moving continuous web 44 with width L2 and pitch P2.

[0041] Changing operating conditions is accomplished solely through software, without the need to replace components and without the need to perform settings or adjustments.

[0042] The control device 40 controls the tool holder roller 12 and the anvil roller 16 in phase with each other to perform the movement, in this case the cut 50 or 52 at the required pitch P1, P2.

[0043] The rotational speeds of the tool holder roller 12 and the anvil roller 16 may be varied during one revolution, respectively, to effect movement at programmed pitches P1, P2.

[0044] When the tools 20, 22, 24 that are operable at any given time cooperate with the respective anvil elements 28, 30, 32, the speed of the tools 20, 22, 24 and anvil elements 28, 30, 32 may be equal to the feed speed V1, V2 of the continuous webs 42, 44 in the machine direction MD. After performing an operation, the tools 20, 22, 24 and respective anvil elements 28, 30, 32 that are operable at any given time may accelerate or decelerate to perform the next operation after the continuous webs 42, 44 have advanced a predetermined pitch P1, P2 in the machine direction MD. Tools that are not operable contact the continuous webs 42, 44 out of phase with respect to the anvil elements 28, 30, 32 and do not perform any operation on the webs 42, 44.

[0045] The apparatus 10 may be configured to perform intermittent operations on moving continuous webs 42, 44, each having an extent in the longitudinal direction of the continuous webs 42, 44.

[0046] Each movement has an extent in the direction of web movement (machine direction MD) that is less than the circumference of the anvil roller 12 divided by the number of possible format changes. For example, if the anvil roller 12 has a radius R and carries n tools, each movement may have a dimension in the machine direction MD that is less than 2πR / n.

[0047] It should be understood that multiple devices 10 can be combined to perform different operations or the same operation with different widths.

[0048] The present invention also relates to a machine for producing absorbent sanitary articles such as diapers, diaper pants, absorbent articles for incontinent adults, etc., comprising a device for treating a continuous moving web as described above.

[0049] Naturally, without prejudice to the principles of the invention, the details of construction and embodiment may be varied in various ways from those described and illustrated, without thereby departing from the scope of the invention as defined by the following claims.

Claims

1. a tool holder roller rotatable about a first axis of rotation and holding at least one first tool and at least one second tool arranged at an angular distance from each other and having different geometrical characteristics; an anvil roller rotatable about a second axis of rotation parallel to said first axis of rotation and carrying at least one anvil element; a control device configured to rotate the tool holder roller and the anvil roller about the first axis of rotation and the second axis of rotation in at least one first operating condition and one second operating condition; wherein in the first operating condition, the first tool is in phase with and cyclically cooperates with at least one anvil element and the at least one second tool is out of phase with and cyclically cooperates with the anvil element, and in the second operating condition, the second tool is in phase with and cyclically cooperates with at least one anvil element and the first tool is out of phase with and cyclically cooperates with the anvil element.

2. The apparatus of claim 1 , wherein the first tool and the second tool have respective lengths that differ from one another.

3. The apparatus of claim 1 or claim 2, wherein the first tool and the second tool are configured to perform an operation selected from cutting, welding, laminating, embossing, and perforating.

4. 3. The apparatus of claim 1 or claim 2, wherein the first tool and the second tool include respective active surfaces configured to perform different operations from each other.

5. 3. The apparatus of claim 1 or claim 2, wherein the first tool and the second tool in the first operating condition and the second operating condition cooperate with the same anvil element.

6. 3. The apparatus of claim 1, wherein the anvil roller carries a plurality of anvil elements spaced angularly apart from one another, and wherein the first tool and the second tool cooperate with each anvil element in the first operating condition and the second operating condition.

7. The apparatus of claim 1 or 2, wherein the first tool and the second tool protrude radially from an outer surface of the tool holder roller.

8. The apparatus of claim 1 or 2, wherein the at least one anvil element projects radially from an outer surface of the anvil roller.

9. 3. The apparatus according to claim 1, wherein the control device is configured to vary the rotational speeds of the tool holder roller and the anvil roller each during one revolution to perform the programmed pitch operation.

10. A machine comprising a device for treating a continuous moving web according to claim 1 or 2.

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