DEVICE FOR RELEASING SECTIONS FROM A MATERIAL WEB

Abstract

A device for releasing sections from a material web has a vacuum cutting cylinder and a counter cylinder for cutting the sections. The device also has a vacuum transfer roll for removing the sections from the vacuum cutting cylinder and a conveyor belt, onto which the sections are capable of being deposited from the vacuum transfer roll.

Claims

1. device (10) for releasing sections (12) from a material web (14), having a vacuum cutting cylinder (20) and a counter cylinder (30) for cutting the sections (12), having a vacuum transfer roll (50) for removing the sections (12) from the vacuum. cutting cylinder (20), having a conveyor belt (70), onto which the sections (12) are capable of being deposited from the vacuum transfer roll (50).

2. The device as claimed in claim 1, wherein the speed of rotation of the vacuum transfer roll (50) is greater than the speed of rotation of the vacuum cutting cylinder (20).

3. The device as claimed in claim, wherein a first motor drive is present, by means of which the vacuum cutting cylinder (20) is capable of being driven in a rotatable manner, and a second motor drive is present, by means of which the vacuum transfer roll (50) is capable of being driven in a rotatable manner.

4. The device as claimed in claim 1, wherein the vacuum cutting cylinder (20) is connected to a compressed air channel.

5. The device as claimed in claim 4, wherein a fixed hollow cylinder is present beneath the outer surface (22) of the vacuum cutting cylinder (20), the fixed hollow cylinder in cross section exhibits at least two chambers, one of the at least two chambers is connected to a vacuum pump, and the other of the at least two chambers is connected to a compressed air channel.

6. The device as claimed in claim 1, wherein the vacuum transfer roll (50) is connected to a compressed air channel.

7. The device as claimed in claim 6, wherein a fixed hollow cylinder is present beneath the outer surface (52) of the. vacuum transfer roll (50), the fixed hollow cylinder in cross section exhibits at least two chambers, one of the at least two chambers is connected to a vacuum pump, and the other of the at least two chambers is connected to a compressed air channel.

8. The device as claimed in claim 1, wherein the conveyor belt is configured as a vacuum conveyor belt (70).

9. The device as claimed in claim 1, wherein the transport speed of the conveyor belt (70) is greater than the speed of rotation of the vacuum transfer roll (50).

Description

BRIEF DESCRIPTION OF THE DRAWING

[0019] The invention is described and explained below on the basis of the illustrative embodiment illustrated in the drawing. In the drawing:

[0020] FIG. 1 depicts a perspective view of the inventive device for releasing sections from a material web, and

[0021] FIG. 2 depicts a perspective view from the side of the inventive device according to FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The inventive device 10 for releasing sections 12 from a material web 14 is illustrated in perspective in FIGS. 1 and 2. The device 10 has a vacuum cutting cylinder 20, which is mounted in a rotatable manner and is displaced by means of a motor drive that is not illustrated here. The outer surface 22 of the vacuum cutting cylinder 20 has a number of cutting edges 24, which form a number of identical depressions 26. The outer shape of the depressions 26 corresponds to the shape of the sections 12 to be cut. A number of openings 28 are present in each depression 26. The openings 28 are connecteddepending on the rotational position of the vacuum cutting cylinder 20to a compressed air channel or to a vacuum line.

[0023] The vacuum cutting cylinder 20 interacts with a counter cylinder 30. The material web 14 is supplied to the device 10 via transport rollers that are not illustrated here and arrives in the transport direction 40 between the vacuum cutting cylinder 20 and the counter cylinder 30. In the present example, the direction of rotation 42 of the counter cylinder 30 runs in a clockwise direction, whereas the direction of rotation 44 of the vacuum cutting cylinder 20 runs in an anticlockwise direction. As the material web 14 is conveyed between the counter cylinder 30 and the vacuum cutting cylinder 20, the individual sections 12 are cut from the material web 14. The sections 12 are initially transported onwards into the depressions 26 in the vacuum cutting cylinder 20, before being transferred to the vacuum transfer roll 50.

[0024] The vacuum transfer roll 50 has in its otherwise smooth outer surface 52 a multiplicity of openings 54, which can be. acted upon by compressed air or by a vacuum, The vacuum transfer roll 50 is mounted in a rotatable manner and is driven in a rotatable manner by its own motor drive. The direction of rotation 56 of the vacuum transfer roll 50 runs in the clockwise direction in the present example. The speed of rotation of the vacuum transfer roll 50 can be selected on account of the separate motor drive regardless of the speed of rotation of the vacuum cutting cylinder 20. In the present example, the speed of rotation of the vacuum transfer roll 50 is slightly greater than the speed of rotation of the vacuum cutting cylinder 20. It is thus possible to separate the cut sections 12 from one another by a certain amount 58 at the time of their transfer to the vacuum transfer roll 50, when viewed in the direction of transport, and to spread them apart in this way. Two adjacent sections 12 in the direction of transport thus no longer lie immediately after one another on the vacuum transfer roll, and in point of fact a small distance (amount 58) is present between them. This small distance reduces the risk of the sections 12 sticking together again due to the cold flowing of the adhesive present in the material web 14 and no longer being capable of being separated cleanly from one another at a later time.

[0025] It is thus not necessary to provide a distance between two sections 12 lying behind one another in the direction of transport 40 of the material web 14 already when cutting with the vacuum cutting cylinder 20, since said distance can be produced subsequently by the transfer to the vacuum transfer roll 50. This reduces the non-reusable remainder of the material web 14, so that the latter consists only of three narrow strips 60, 62, 64.

[0026] The two edge strips 60, 64 are required in order to be able to cut out slightly rounded sections 12 at the corners. In addition, no edge strips 60, 64 would be necessary to the extent that it is possible to dispense with the roundings of the corner regions. The middle strip 62. in the present example is required in order likewise to be able to ensure a certain distance between two neighbouring sections 12 in the longitudinal direction of the vacuum cutting cylinder 20, so that these are not able to adhere to one another once more due to cold flowing. This can result in more or fewer central strips 62, depending on the width of the material web 14 and the product size of the sections 12.

[0027] The removal of the sections 12 from the depressions 26 of the vacuum cutting cylinder usually requires the presence of a vacuum on the vacuum transfer roll 50. Depending on the material of the material web 14, it may be sufficient if the vacuum of the vacuum transfer roll 50 is greater than the vacuum of the vacuum cutting cylinder 20. In the event of this difference in pressure not being sufficient, the vacuum of the vacuum cutting cylinder 20 can be increased in the transfer region between the vacuum transfer roll 50 and the vacuum cutting cylinder 20. A pulse of compressed air could also take place, if necessary, in order to eject the cut sections 12 from the depressions 26 and to transfer them rapidly and precisely onto the vacuum transfer roll 50.

[0028] The cut sections 12 are transferred from the vacuum transfer roll 50 onto a vacuum conveyor belt 70. The transport speed of the vacuum conveyor belt 70 is slightly greater in the present case than the speed of rotation of the vacuum transfer roll 50. As a result, the distance 72 between two sections 12 lying one after the other on the vacuum conveyor belt 70 is slightly larger than the distance 58 between two sections 12 on the vacuum transfer roll 50. This can further reduce the risk of adhesion due to cold flowing.

[0029] The vacuum conveyor belt 70 can then transfer the cut sections 12 to further web-processing stations, in order to process the sections 12 further, for example into transdermal therapeutic dressings. Because of the resulting small amount of waste, the device 10 is particularly suitable if the material web contains the therapeutic active substance, since suchlike material webs are correspondingly cost-intensive and should be optimally utilized.

[0030] Different vacuum cutting cylinders 20 may be utilized in the inventive device 10 depending on the size and shape of the. desired sections 12. The storage of the vacuum cutting cylinder 20 can be selected so that vacuum cutting cylinders 20 of different diameters can also be utilized in the device without major problems, so that a rapid change to the format of the device 10 is possible.