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Title:
DEVICE FOR PROCESSING A CONTINUOUS WEB FOR ABSORBENT ARTICLES
Document Type and Number:
WIPO Patent Application WO/2021/044236
Kind Code:
A1
Abstract:
A device for processing a continuous web for absorbent articles, comprising a cutting means (2), which rotates about its axis of rotation (2a), and an opposing means (3), which rotates about its axis of rotation (3a); the cutting means (2) has a plurality of cutting elements (4) and the opposing means (3) has a plurality of anvils (5) each intended to operate in conjunction with a cutting element (4) to cut the continuous web (19) into respective separate pieces (29); during the rotation of the cutting elements (4) about the axis of rotation (2a) of the cutting means (2), the cutting edge of each blade (6) defines a frustoconical trajectory (24); during the rotation of the anvil (5) about the axis of rotation (3a) of the opposing means (3), the opposing surface (7) of each anvil (5) defines a frustoconical trajectory (25); the frustoconical trajectory (24) defined by the blades (6) of the cutting elements (4) and the frustoconical trajectory (25) defined by the anvil (5) have a line of tangency (27) in common between the two frustoconical trajectories (24; 25) along which each cutting element (4) contacts an anvil (5) to cut the continuous web, thus defining a cutting station (17) where the continuous web (19) is cut.

Inventors:
PIANTONI MATTEO (IT)
SACCOMANI ALESSANDRO (IT)
ROSANI MARCO (IT)
RESMINI GABRIELE (IT)
Application Number:
IB2020/057531
Publication Date:
March 11, 2021
Filing Date:
August 11, 2020
Export Citation:
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Assignee:
GDM SPA (IT)
International Classes:
B26D1/56; B26D7/20
Foreign References:
US20050115665A12005-06-02
US4378737A1983-04-05
Attorney, Agent or Firm:
CASADEI, Barbara (Via di Corticella 87, Bologna, IT)
Download PDF:
Claims:
CLAIMS

1. A device for processing a continuous web for absorbent articles, comprising a cutting means (2), which rotates about its axis of rotation (2a), and an opposing means (3), which rotates about its axis of rotation (3a); the cutting element (2) has at least one cutting element (4) and the opposing means (3) has at least one anvil (5); the cutting element (4) has a respective blade (6) having a respective cutting edge; the anvil (5) has a respective opposing, or contrasting, surface (7) set against the blade (6) of the cutting element (4); characterized in that the axis of rotation (2a) of the cutting means (2) and the axis of rotation (3a) of the opposing means (3) are incident on each other to make at least an acute angle “a” between them; during the rotation of the cutting element (4) about the axis of rotation (2a) of the cutting means (2), the cutting edge of the blade (6) defines a frustoconical trajectory (24); during the rotation of the anvil (5) about the axis of rotation (3a) of the opposing means (3), the opposing surface (7) of the anvil (5) defines a frustoconical trajectory (25); the frustoconical trajectory (24) defined by the cutting edge of the blade (6) of the cutting element (4) and the frustoconical trajectory (25) of the opposing surface (7) of the anvil (5) have a line of tangency (27) in common between the two trajectories (24, 25) and along which the cutting element (4) contacts the anvil (5) to cut the continuous web, thus defining a cutting station (17) where the continuous web (19) is cut.

2. The device according to independent claim 1 , characterized in that the cutting means (2) comprises a rotary shaft (8) rotating about the axis of rotation (2a) and at least one support (9) for a respective cutting element (4); the support (9) comprises a first portion (10) that extends along a direction transverse to the axis of rotation (2a) of the shaft (8) and a second portion (11) having a cavity (20) for receiving the cutting element

(4) and disposed in such a way that the cutting edge of the blade (6) is inclined to the direction defined by the axis of rotation (2a) of the shaft (8).

3. The device according to claim 2, characterized in that each support (9) is configured to dispose the cutting element (4) in such a way that the cutting edge of the blade (6) is disposed along a direction incident on the axis of rotation (2a) of the shaft (8) and making an acute angle therewith.

4. The device according to any one of the preceding claims, characterized in that the opposing means (3) comprises a rotary shaft (12) rotating about the axis of rotation (3a) and at least one support (13) for a respective anvil

(5); each support (13) comprises a first portion (14) that extends along a direction transverse to the axis of rotation (3a) of the shaft (12) and a second portion (15) having a cavity (16) for receiving the anvil (5) and disposed in such a way that the edge of the opposing surface (7) of the anvil (5) is inclined to the direction defined by the axis of rotation (3a) of the shaft (12).

5. The device according to claim 4, characterized in that each support (13) is configured to dispose the anvil (5) in such a way that the cutting edge of the opposing surface (7) is disposed along a direction incident on the axis of rotation (3a) of the shaft (12) and making an acute angle therewith.

6. The device according to any one of the preceding claims, characterized in that the cutting element (4) is configured to vary its position relative to the axis of rotation (2a) of the cutting means (2).

7. The device according to claim 6, characterized in that the cutting element (4) is configured to vary its position along the direction incident on the axis of rotation (2a) of the cutting means (2).

8. The device according to any one of the preceding claims, characterized in that the anvil (5) is configured to vary its position relative to the axis of rotation (3a) of the opposing means (3).

9. The device according to claim 8, characterized in that the anvil (5) is configured to be positioned along the direction incident on the axis of rotation (3a) of the opposing means (3).

10. The device according to any one of the preceding claims, characterized in that the cutting edge of the blade (6) extends along a direction incident on the axis of rotation (2a) of the cutting means (2), making an acute angle therewith.

11. The device according to any one of the preceding claims, characterized in that the opposing surface (7) of the anvil (5) extends along a direction incident on the axis of rotation (3a) of the opposing means (3), making an acute angle therewith.

12. A unit for making absorbent articles comprising a device for processing a continuous web for absorbent articles according to any one of claims 1 to 11.

13. A method for processing a continuous web for absorbent articles characterized in that it comprises processing the continuous web along a line of tangency (27) in common between a frustoconical trajectory (24) defined by the rotation of a cutting edge of a blade (6) of a cutting element (4) and a frustoconical trajectory (25) defined by the rotation of an opposing surface (7) of an anvil (5).

Description:
DEVICE FOR PROCESSING A CONTINUOUS WEB FOR ABSORBENT ARTICLES

Technical field

This invention relates to a device for processing a continuous web for absorbent articles.

The device is applied in particular in the sector of absorbent articles, such as diapers for children or incontinence pants for adults, involving the cutting of material which consists of a continuous web into separate individual pieces intended to form an absorbent article.

In particular, but without limiting the scope of the invention, the device disclosed is particularly suitable for cutting a continuous web of elastic material into separate individual pieces of elastic material.

Background art

It is well known that, in the absorbent articles sector, the cutting device comprises a rotary means having a cylindrical shape, rotating about its axis of rotation, and an opposing means having a cylindrical shape, rotating about its axis of rotation.

The axes of rotation of the cutting means and of the opposing means extend along respective directions which are parallel to each other.

In this context, the need was felt to make a device for processing a continuous web for absorbent articles.

Disclosure of the invention

The device comprises a cutting means, which rotates about its axis of rotation, and an opposing means, which rotates about its axis of rotation. The cutting means has at least one cutting element and the opposing means has at least one anvil.

The cutting element has a respective blade having a respective cutting edge. The anvil has a respective opposing, or contrasting, surface set against the blade of the cutting element.

The axis of rotation of the cutting means and the axis of rotation of the opposing means are incident on each other to make at least an acute angle “a” between them;

During the rotation of the cutting element about the axis of rotation of the cutting means, the cutting edge of the blade defines a frustoconical trajectory.

During the rotation of the anvil about the axis of rotation of the opposing means, the opposing surface of the anvil defines a frustoconical trajectory. The frustoconical trajectory defined by the cutting edge of the blade of the cutting element and the frustoconical trajectory of the opposing surface of the anvil have a line of tangency in common between the two trajectories and along which the cutting element contacts the anvil to cut the continuous web, thus defining a cutting station where the continuous web is cut.

Advantageously, the inclination of the axes allows the dimensions to be limited relative to the shape of the prior art devices and allows the device to be coupled to any unit for processing separate pieces obtained by the cutting device, free from the kinematic mechanisms of the latter.

Brief description of drawings

Further features and advantages of this invention are more apparent in the non-limiting description of a preferred but non-exclusive embodiment of a device for processing a continuous web for absorbent articles, as illustrated in the accompanying drawings, in which:

Figure 1 is a schematic perspective view of a first embodiment of a device for cutting a continuous web into separate pieces of absorbent articles according to this invention;

Figure 2 is a schematic perspective view of a second embodiment of a device for cutting a continuous web into separate pieces of absorbent articles according to this invention;

Figures 3 and 4 are front schematic views of a detail of the device of Figures 1 and 2;

Figure 5 is a front schematic view of an operating diagram of the cutting device according to this invention.

Detailed description of preferred embodiments of the invention

With reference to the accompanying figures, the numeral 1 denotes a device for processing a continuous web for absorbent articles according to this invention.

The term “processing” means cutting the continuous web in order to sever it into pieces or perforating of the continuous web means an alternating sequence of cuts, for example in the form of dots or lines, which allows the continuous web to remain whole as it is fed. In this sense, perforating shall be understood to refer to pre-cutting before severing the web with the final cut.

It is possible to use a continuous web processing device 1 according to this invention to perform the pre-cutting and a continuous web processing device 1 according to this invention to perform the final cut. In that sense, there could be two devices 1 in series, one disposed after the other according to the direction of feed of the continuous web.

A feed system 18 for feeding a continuous web 19 is disposed upstream of the device 1 , with reference to the direction of feed of the continuous web 19. The continuous web 19 may be a laminated web with elastics or, in general, unprocessed or pre-worked material.

The device 1 comprises a cutting means 2, which rotates about its axis of rotation 2a, and an opposing means 3, which rotates about its axis of rotation 3a. In the embodiment illustrated, the cutting means 2 is configured to support at least one cutting element 4 during the rotation about its axis of rotation 2a.

Each cutting element 4 has a respective blade 6 having a respective cutting edge.

In the embodiment illustrated, the opposing means 3 is configured to support at least one anvil 5 during the rotation about its axis of rotation 3a. It should be noticed that the cutting means 2 and the opposing means 3 may have the same number of cutting elements 4 and anvils 5 or they may have a different number of cutting elements 4 and anvils 5.

Each anvil 5 has a respective opposing, or contrasting, surface 7 set against the blade 6 of the cutting element 4.

During the rotation of the cutting means 2 and of the opposing means 3, each cutting element 4 of the cutting means 2 is intended to operate in conjunction with an anvil 5 of the opposing means 3 to cut the continuous web into respective separate pieces 29. According to this invention, the axis of rotation 2a of the cutting means 2 and the axis of rotation 3a of the opposing means 3 are incident on each other to make at least an acute angle a between them.

According to this embodiment, the cutting edge of the blade 6 extends along a direction incident on the axis of rotation 2a of the cutting means, making an acute angle therewith.

In this way, during the rotation of the cutting element 4 about the axis of rotation 2a of the cutting means 2, the cutting edge of each blade 6 defines a frustoconical trajectory 24, as schematically illustrated in Figure 4 and 5. According to this embodiment, the opposing surface 7 of the anvil 5 extends along a direction incident on the axis of rotation 3a of the opposing means 3.

In this way, during the rotation of the anvil 5 about the axis of rotation 3a of the opposing means 3, the opposing surface 7 of each anvil 5 defines a frustoconical trajectory 25, as schematically illustrated in Figure 4 and 5. The frustoconical trajectory 24 defined by the cutting edges of the blades 6 of the cutting elements 4 and the frustoconical trajectory 25 of the opposing surface 7 of the anvil 5 have a line of tangency 27 in common between the two trajectories, along which each cutting element 4 contacts an anvil 5 to cut the continuous web, thus defining a cutting station 17 where the continuous web is cut.

At the cutting station 17, the cutting edge of the blade 6 and the opposing surface 7 of the anvil 5 are aligned with each other along the direction of the line of tangency 27 of the frustoconical trajectories 24, 25.

It should be noticed that, the point of incidence of the axis of rotation 2a of the cutting means 2 and the axis of rotation 3a of the opposing means 3 is the common vertex of the above-mentioned frustoconical trajectories 24 and 25.

The cutting means 2 comprises a rotary shaft 8 rotating about its axis of rotation 2a, that is to say, the axis of rotation of the cutting means 2.

The cutting means 2 comprises a plurality of supports 9, each for a respective cutting element 4.

Each support 9 is configured to dispose the cutting element 4 in such a way that the cutting edge of each blade 6 is disposed along a direction incident on the axis of rotation 2a of the shaft 8 and making an acute angle therewith..

In particular, each support 9 comprises a first portion 10 that extends along a direction transverse to the axis of rotation 2a of the shaft 8 and a second portion 11 having a cavity 20 for receiving the cutting element 4. That receiving cavity 20 is configured to dispose the cutting element 4 with the cutting edge of the blade 6 along a direction incident on the axis of rotation 2a of the shaft 8 and making an acute angle therewith.

The opposing means 3 comprises a rotary shaft 12 rotating about its axis of rotation 3a, that is to say, the axis of rotation of the opposing means 3. The opposing means 3 comprises a plurality of supports 13, each for a respective anvil 5.

Each support 13 is configured to dispose the anvil 5 in such a way that the opposing surface of each anvil 5 is disposed along a direction incident on the axis of rotation 3a of the shaft 12 of the opposing means 3 and making an acute angle therewith.

In particular, each support 13 comprises a first portion 14 that extends along a direction transverse to the axis of rotation 3a of the shaft 12 and a second portion 15 having a cavity 16 for receiving the anvil 5.

That receiving cavity 12 is configured to dispose the cutting element 4 with the cutting edge of the blade 6 along a direction incident on the axis of rotation 2a of the shaft 8 and making an acute angle therewith.

It should be noticed that, the shaft 8 of the cutting means 2 and the shaft 12 of the opposing means 3 rotate in opposite directions to each other.

In particular, at the end of the shaft 8 of the cutting means 2 there is a motion transmission means 21 configured to drive the rotation of the shaft 8 about its axis of rotation 2a.

At the end of the shaft 12 of the opposing means 3 there is a motion transmission means 22 configured to drive the rotation of the shaft 12 about its axis of rotation 3a.

According to one alternative embodiment, the transmission means 21 , 22 of the cutting means 2 and of the opposing means 3 are kinematically connected to each other.

In that embodiment, only one of the two transmission means 21 , 22 is connected to a motion actuating means.

In particular, the transmission means 21 , 22 of the cutting means 2 and of the opposing means 3 are in the form of bevel gears.

According to one alternative embodiment, the transmission means 21 , 22 of the cutting means 2 and of the opposing means 3 are moved synchronised with each other by respective actuating means.

According to one alternative embodiment, the device 1 according to this invention may be placed in use inside a frame 23 for receiving the device 1 , as shown in Figure 2.

The advantages of that configuration are the compact dimensions of the device 1 , ease of adjustment or maintenance, and the rigidity of the framework.

According to a further alternative embodiment, the device 1 may be coupled “in view” to a unit 26 for processing separate pieces 29 cut by the device 1 itself.

That unit 26 may be a rotary unit 26 rotating about its axis of rotation 26a, in particular horizontal, supporting a plurality of shoes 28 for gripping and releasing respective separate pieces 29.

In this case, once the cutting elements 4 and the anvils 5 have encountered each other in the cutting station 17, they will disengage from each other moving away from the unit 26 for processing the separate pieces 29, moving out of the operating plane of the operating unit, thanks to the respective frustoconical trajectory 24, 25.

The disengagement of each cutting element 4 from the respective anvil 5 therefore occurs in the space.

That allows addition of the cutting function to a unit for processing separate pieces 29, without causing a significant impact on the design of the latter.

Access to the device 1 allows more convenient adjustment of the elements involved in the cutting and easier maintenance of the elements.

Regarding the possibility of adjusting the position of the elements involved in the cutting, each cutting element 4 is configured to be positioned along the direction incident on the axis of rotation 2a of the cutting means 2.

The configuration adopted by each cutting element 4 determines its distance from the axis of rotation 2a of the cutting means 2.

Each anvil 5 is configured to be positioned along the direction incident on the axis of rotation 3a of the opposing means 3.

The configuration adopted by each cutting element 4 determines its distance from the axis of rotation 3a of the opposing means 3.

By means of adjustment of the relative position of the cutting elements 4 and the anvils 5, respectively relative to the axis of rotation 2a of the cutting means 2 and to the axis of rotation 3a of the opposing means 3, it is possible to vary the operating diameter and therefore the speeds of rotation.

The variation in the operating diameter translates into the variation of the cutting point, which moves away from or towards the centre of the generatrix of the frustoconical trajectory.