Device for processing moving continuous web and machine having the same

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] The present invention generally relates to processing a continuously moving web.

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

[0003] The present invention has been specifically developed for its application to the production of absorbent hygiene products such as diapers, diaper pants, and incontinence absorbent products for adults, but is not limited to this particular field.

[0004] According to another aspect, the present invention relates to a machine comprising an apparatus for processing a continuously moving web.

Background Art

[0005] In order to produce absorbent hygiene products, it is often necessary to perform various types of processing on a continuously moving web, such as a continuous composite material web comprising a plurality of elastic threads encapsulated between one or more nonwoven layers. The processing operations can include, for example, cutting, welding, embossing, perforating, etc.

[0006] These operations are usually performed using an apparatus comprising an anvil roller and a tool holder roller on which tools such as a cutting blade, a welding element, an embossing element, etc. are arranged according to the processing operation to be performed.

[0007] Rotary machines for processing a continuously moving web are configured to operate on a web corresponding to a particular format of absorbent hygiene products.

[0008] When the format of the absorbent hygiene products produced on the same line is changed, the range of operations that have to be performed on the continuous web used for producing the absorbent hygiene products often also changes.

[0009] Typically, when the form of an absorbent hygiene product is changed, the rotary tool that performs operations such as cutting, welding, and embossing must be replaced to adapt the width of the tool to the new size of the product to be produced.

[0010] The solution currently adopted to make the form change is to replace the rotary unit completely or partially.

[0011] The form change is one of the most complex and time-consuming operations because it requires the disengagement of the unit's rotary shaft transmission, pneumatic connections, and mechanical fasteners, especially in hard-to-reach locations.

[0012] Furthermore, the removal of the unit requires the presence of an access space in the line for a lifting device such as a forklift truck, which significantly limits the possibility of using the space in front of the machine.

[0013] In some cases, it may be necessary to replace only the toolholder rollers of the device, but this also requires a very delicate (on the order of microns) adjustment operation, which may result in the risk of damaging the tool. SUMMARY OF THE INVENTION

[0014] The object of the present invention is to provide a device for processing a continuously moving web that overcomes the problems of the prior art. According to the present invention, this object is achieved by a device having the features described in claim 1.

[0015] According to another aspect, the present invention relates to a machine as described in claim 10.

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

[0017] The claims form an essential part of the present disclosure provided herein with respect to the present invention.

Brief Description of the Drawings

[0018] Next, the present invention will be described in detail with reference to the accompanying drawings, which are given merely as non-limiting examples.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0019] Referring to FIGS. 1 to 4, the numeral 10 indicates an apparatus for processing a continuously moving web.

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

[0021] The tool holder roller 12 holds at least one first tool 20 and at least one second tool 22 arranged at an angle from each other. Generally, the tool holder roller 12 can hold a generic number of tools equal to or greater than 2. In the example shown in the figure, the tool holder roller 12 holds a first tool 20, a second tool 22, and a third tool 24.

[0022] In the following, the case where the tool holder roller 12 holds the first tool 20 and the second tool 22 will be referred to as an example, but it should be understood that the content described is equally applicable when the tool holder roller 12 holds an equal to or greater than two general number of tools.

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

[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 various machining operations, such as machining of the same type but different patterns, or machining operations different from each other, such as welding, embossing, etc.

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

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

[0028] In the embodiments shown in FIGS. 1 and 2, the anvil roller 16 holds a single anvil element 28. In this case, as will be described below, the first tool 20, the second tool 22, and any additional tool 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, 24.

[0029] In the embodiment shown in FIGS. 3 and 4, the anvil roller 16 holds a plurality of anvil elements 28, 30, 32 that are angularly spaced from each other. In this case, as will be described below, the first tool 20, the second tool 22, and any additional tool 24 are intended to cooperate with each anvil element 28, 30, 32. In this case, each tool 20, 22, 24 can be set with the corresponding anvil element 28, 30, 32.

[0030] Each of the anvil elements 28, 30, 32 can project radially from the 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 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 axes of rotation 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 the first operating condition, the first tool 20 of the tool holder roller 12 is in phase with a single anvil element 28 or each anvil element 28, 30, 32 and periodically cooperates with a single anvil element 28 or each anvil element 28, 30, 32 during operation to perform a machining operation on a continuously moving web. In the first operating condition, the second tool 22 and any additional tool 24 are out of phase with respect to a single anvil element 28 or with respect to the plurality of anvil elements 28, 30, 32 and do not cooperate with any of the anvil elements 28, 30, 32 during operation.

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

[0035] Accordingly, the apparatus 10 can operate under various operating conditions, but only one type of tool is operable under each of its operating conditions, and the apparatus 10 can be switched from one operating condition to another using software selection.

[0036] The transition from one operating condition to another results in the possibility of changing the geometry of the machining being performed on the continuously moving web, corresponding to a change in the form of the apparatus 10.

[0037] Figures 5 and 6 show two continuous webs 42, 44 machined by the apparatus 10 under the first and second operating conditions, respectively. In the example shown, the continuous webs 42, 44 are elastic bands comprising a plurality of longitudinal elastic threads 46, 48 encapsulated between two non-woven layers. The longitudinal elastic threads 46, 48 are attached between the two continuous webs 42, 44 by adhesives applied discontinuously. Lines 54 and 56 define windows where no adhesive is applied and the longitudinal elastic threads 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 operation in the apparatus 10 in order to transversely cut the longitudinal elastic threads 46, 48 at regular intervals. In FIGS. 5 and 6, the transverse cuts are shown at 50 and 52, having widths L1 and L2 respectively. After the transverse cuts 50, 52, the longitudinal elastic threads 46, 48 of the portions not attached to the two continuous webs 42, 44 each contract to the line 56.

[0039] In a first operating condition, the apparatus 10 is configured to operate with a first tool 20 having a width L1, and the first tool 20 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, and the second tool 22 periodically cooperates with one of the anvil elements 28, 30, 32 to make a second cut 52 in the second moving continuous web 44 with a width L2 and a pitch P2.

[0041] The change of the operating condition is performed only by software without the need to replace components and without the need to make settings or adjustments.

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

[0043] The rotational speeds of the tool holder roller 12 and the anvil roller 16 may change during each rotation in order to operate at the programmed pitches P1, P2.

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

[0045] Device 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 operation has an extent smaller than the size obtained by dividing the circumference of anvil roller 12 by the possible number of format changes in the direction of web movement (machine direction MD). For example, if anvil roller 12 has a radius R and holds n tools, each operation may have a dimension smaller than 2πR / n in the machine direction MD.

[0047] It should be understood that a plurality of 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 hygiene products such as diapers, diaper pants, absorbent articles for incontinent adults, etc., comprising a device for processing a continuously moving web as described above.

[0049] Of course, without impairing the principles of the present invention, the details of the structure and embodiments may be variously changed with respect to those described and illustrated, and do not thereby depart from the scope of the present invention 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 angle from each other and having different geometric 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; and wherein in the first operating condition, the first tool is in phase with and periodically cooperates with at least one anvil element and the at least one second tool is out of phase with and out of cooperation with the anvil element, and in the second operating condition, the second tool is in phase with and periodically cooperates with at least one anvil element and the first tool is out of phase with and out of cooperation 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 punching.

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 2, wherein the first tool and the second tool in the first operating condition and in the second operating condition cooperate with the same anvil element.

6. 3. The apparatus of claim 1 or 2, wherein the anvil roller carries a plurality of anvil elements arranged angularly spaced from one another, and in the first operating condition and the second operating condition, the first tool and the second tool cooperate with each anvil element.

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. 10. The apparatus of 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 a 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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