SE533300C2 - Device for removing an end seal - Google Patents

Description

2 25 30 35 533 SÛÛ 2 are separated from each other to allow the insertion of a filling nozzle.

This is because in some cases the walls of the filling channel tend to stick together right at the cut surface. A contributing factor to this phenomenon is smearing of the packaging material, which smearing occurs in the cut surface in connection with the removal of said end closure. Another contributing factor to this phenomenon is a cold weld that occurs in the cut surface between the side walls of the package. Said cold weld is produced as a result of compression of the packaging material in connection with the cutting, ie each cut surface of the side surfaces of the package is pressed against each other and molecular bonds which cause the sides to adhere to each other arise. The word cold welding is used because the adhesion takes place at a temperature which is significantly below the temperature at which the packaging material melts.

An alternative way of removing the end closure is to use a crushing knife in which a rotatably arranged knife with a circumferential, peripheral edge is applied to a stationary abutment to form a nip in which the web of packages is inserted to remove the end closure. Even when the end closure is removed in this way, the above-mentioned problem arises. That is, smearing of the packaging material and cold welding in the cut surface.

Another alternative is to use a stationary knife of the razor blade type. In this way, a removal of the end closure is achieved largely without smearing of the packaging material or cold welding of the walls of the filling channel at the cut surface. Another problem that arises in this context, however, is the wear of the knife. The same point is responsible for the cutting all the time, which is why the knife quickly wears out and needs to be replaced, which leads to frequent production stops.

Thus, there is a need to provide a reliable and simple way of removing an end closure of a package of collapsing type, which method also allows subsequent simple and reliable separation of the walls of the opened filling channel.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a device for reliable and easy removal of an end closure of a package of collapsing kind.

Another object of the present invention is that the device for reliable and simple removal of an end closure of a package of 10 15 20 25 30 35 l 'in M3 lll-Il ILO' Ei l-.fll 3 collapsing types also allows subsequent simple and reliable separation of the walls of the opened filling channel.

In order to achieve the above and further unspecified objects, which will appear from the following description, the present invention relates to a device according to claim 1. Embodiments of the device appear from claims 2-14.

According to a first aspect of the invention, this relates to a device for removing an end closure of a package of collapsing kind, which end closure closes a channel delimited by two opposite side walls of the package. The device comprises a cutting disc with circumferentially arranged, pointed teeth and an abutment disc.

The teeth of the cutting disc together define a circumferentially extending cutting disc edge. The cutting disc is further rotatably arranged about a first axis of rotation. The abutment disc is also rotatably arranged about a second axis of rotation. Said second axis of rotation is parallel to said first axis of rotation. Furthermore, the cutting disc has a radially elongated, peripheral cutting disc surface which partially defines said cutting disc edge. The abutment plate has a radially elongated, abutment plate surface which faces the first cutting disc surface. The cutting disc surface of the cutting disc and the abutting disc surface of the abutment disc are arranged with an overlapping abutment to form a cutting nip.

In this way a device is provided which allows reliable and easy removal of an end closure of a package of collapsing kind. The removal of the end closure made with the device also allows subsequent simple and reliable separation of the walls of the opened filling channel. The pointed teeth of the cutting disc allow a snap-action pulsating shear when removing the end closure. Experiments have shown that the removal of the end closure of packages made with the device defined above counteracts smearing of the packaging material and cold welding of the walls of the filling channel at the cut surface. Furthermore, it has also been found that small air pockets occur between the two opposite side walls of the package when the end closure is removed with the device according to the invention. These air pockets occur where the pointed teeth engage the package. The air pockets allow air to easily penetrate between the two opposite side walls of the package when these are separated. The fact that air can easily flow into the package when the side walls of the package are separated means that said separation of the side walls becomes much easier to perform. This, together with the fact that the packaging material in the section across the side walls of the package does not smear or stick together, allows a simple and reliable opening of the channel of the package after the end closure has been removed.

Each tooth of the cutting disc may have an angular tip in a plane perpendicular to said first axis of rotation. If the package whose end closure is to be removed is fed towards the cutting nip in a plane which is substantially parallel to said first and second axis of rotation, a perpendicular engagement between the package and the tip is allowed. In this way, a minimal contact surface is obtained between the package and the tip when removing the end closure.

Said tip may be located at a maximum distance from the center of rotation of the cutting disc. At least one of the abutment disc and the cutting disc may be biased in the axial direction towards the other of the abutment disc and the cutting disc. In this way a better cutting / cutting action is achieved in said nip 45.

Pre-tensioning can be effected by means of a spring which acts for axial displacement of one of the first or second shaft in such a direction that the cutting disc surface of the cutting disc and the abutting disc surface of the abutment disc are pressed against each other. It will be appreciated that either the abutment disc may be biased toward the cutting disc or the cutting disc may be biased toward the abutment disc.

Alternatively, the abutment disc may be biased against the cutting disc while the cutting disc is biased against the abutment disc.

Said abutment disc may comprise a circumferentially extending abutment disc edge, said abutment disc surface partially defining said abutment disc edge. Because the abutment disc also has an edge, a better de-cut cutting pinch is obtained.

The device may further comprise a drive means arranged for rotation of at least one of the abutment disc and the cutting disc.

The drive means can be arranged for simultaneous rotation of the cutting disc and the abutment disc.

The drive means can be arranged for rotation of the cutting disc and the abutment disc in opposite directions. In this way, the direction of movement of the cutting disc and the abutment disc where the two discs overlap can be made to be substantially the same as the direction of movement of the packages fed into the device, the end closures of which are to be removed. Said cutting disc surface and abutment disc surface may be complementary to allow said overlapping abutment. In particular, said cutting disc surface and abutment disc surface may be flat. In this way, the cutting disc and the abutment disc can be easily rotated.

Said cutting disc edge may have an edge angle in the range 10-60 °.

Said retaining disc edge may have an edge angle in the range 20-90 °.

When both the cutting disc edge and the abutment disc edge have acute edge angles, a well-defined nip is obtained in which the cutting / clipping takes place and thus the cutting effect is better. The sharper the edges, the better the clipped pinch is obtained, which means that a better cutting effect is obtained. However, the sharpness must be weighed against the life of each edge. The sharper the edge, the shorter the life.

The cutting disc can have a cross section with the shape of a truncated cone.

The cutting disc may have a first cutting disc main surface and a second cutting disc main surface opposite to the first cutting disc main surface and a radially outer cutting disc side surface connecting the first cutting disc main surface to the second cutting disc main surface.

Said cutting disc side surface may be grooved. The teeth of the cutting disc can be easily formed by milling said grooves in said cutting disc side surface.

The abutment disc may have a cross section with the shape of a truncated cone.

Brief Description of the Drawings Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings.

Figure 1 is a schematic view of a process for producing packages of collapsing types.

Figure 2 is a perspective view of an unfilled package of collapsing type.

Figure 3 is a perspective view of an embodiment of a device for removing an end closure of a package of collapsing type.

Figure 4 is a further perspective view of the embodiment of the device for removing an end closure of a package of collapsing kind shown in Figure 3.

Figure 5 is a side view of the device for removing an end closure of a package of collapsing type shown in Figure 3.

Figure 6 is a bottom view of the device for removing an end closure of a package of collapsing type shown in Figure 3. Figure 7 is a view from above, in magnification, of a package of collapsing type whose end closure is removed.

Figure 8 is a bottom view of an alternative embodiment of the device for removing an end closure of a package of collapsing type.

Description of exemplary embodiments Figure 1 illustrates an example which does not limit the invention to a process for producing packages 1 of a collapsing type.

The packages 1 are manufactured from an M-weight packaging web 2 which comprises two opposite side wall-forming portions 2a, 2b and a folded bottom wall-forming portion 3 arranged therebetween. The packaging web 1 is preferably manufactured from a flexible, laminated packaging material.

The packaging material may comprise a backing layer of a polyolefin material.

The backing layer may further comprise a filler of mineral material which may advantageously consist of chalk (calcium carbonate).

To form a package 1, the two side wall-forming portions 2a, 2b and the bottom-forming portion 3 are brought together in a tool 10.

The tool 10 connects the portions 2a, 2b, 3 along a connecting portion 4 for delimiting a chamber 5. The tool 10 can for example connect the connecting portions 4 by means of a friend, pressure, ultrasound or a combination thereof. The finished package 1 has a tight chamber 5.

The finished packages 1 are interconnected. In this way, an elongated web of packages is formed 1. Excess material that is not included in the packages can be removed, for example in a roller punch (not shown).

The elongate web of packages 1 can later be rolled up on a bobbin to form a roll with a web of interconnected empty packages 1. The roll can then be distributed to a filling plant for use in a filling machine. Figure 2 illustrates a package 1 of the above type.

The package 1 comprises two opposite side walls 6a, 6b and a bottom wall 7 folded into a double-walled shape.

The side walls 6a, Bb of the package together delimit a channel 8 which is closed in the shown unfilled state of the package. By removing an end closure 9 of the package 1, said channel 8 is opened, whereby the chamber 5 of the package 1 can be connected to the surroundings via said channel 8 to allow filling of the package. The channel 8 is arranged for resealing after filling, for example by heat sealing.

The present invention relates to a device 12 for removing an end closure 9 of a package 1 of a collapsing type, and embodiments of the invention according to the invention will now be described.

Referring to Figures 3-6, an embodiment of an inventive device 12 for removing the end closure 9 of a package 1 of collapsing type is shown, which end closure 9 closes the channel 8 defined by the two opposite side walls 6a, 6b of the package 1.

The device 12 comprises a cutting disc 20 and an abutment disc 30.

The cutting disc 20 has, in the embodiment shown, a cross section with the shapes of a truncated cone, see especially 5. figure 5. The abutment disc 30 also has, in the embodiment shown, a cross section with the shape of a truncated cone, see especially 5. figure 5. The cutting disc 20 is supported by a first shaft and arranged for symmetrical rotation about a first axis of rotation 26. The abutment disc 30 is supported by a second shaft and arranged for symmetrical rotation about a second axis of rotation 36.

Said second axis of rotation 36 is parallel to said first axis of rotation 26. In the embodiment shown, said first and second axes extend along said first and second axis of rotation 26, 36, respectively.

The cutting disc 20 has a circumferentially extending cutting disc edge 22. The cutting disc 20 further has a radially extending, peripheral and circumferential cutting disc surface 24. Said cutting disc surface 24 partially defines said cutting disc edge 22.

The abutment disc 30 has a radially extending, peripheral and circumferential abutment disc surface 34. Said abutment disc surface 34 faces said first cutting disc surface 24. Further, the cutting disc surface 24 of the cutting disc 20 and the abutment disc surface 34 of the abutment disc 30 are provided with an overlapping cutting nipple 45.

To allow said overlapping abutment, said cutting disc surface 24 and abutment disc surface 34 are complementary. Advantageously, said cutting disc surface 24 and abutment disc surface 34 are flat. In the embodiment shown in Figures 3-6, the cutting disc 20 is arranged below the retaining disc 30. However, it will be appreciated that the cutting disc 20 and the retaining disc 30 may change places.

In order to provide the required cutting action / cutting action in said nip 45, the cutting disc surface 24 of the cutting disc 20 and the abutment disc surface 34 of the retaining disc 30 are provided with a loaded overlapping abutment, by which is meant that the discs are pressed against each other. This can be achieved by at least one of the retaining disc 30 and the cutting disc 20 being biased in the axial direction towards the other of the retaining disc 30 and the cutting disc 20. This biasing can be achieved by means of a spring which acts for axial displacement of one of the first or second shaft in such a direction that the cutting disc surface 24 of the cutting disc 20 and the abutting disc surface 34 of the abutment disc 30 are pressed against each other. It will be appreciated that either the retaining disc 30 may be biased toward the cutting disc 20 or the cutting disc 20 may be biased toward the retaining disc 30. Alternatively, the retaining disc 30 may be biased toward the cutting disc 20 while the cutting disc 20 is biased toward the retaining disc 30. However, it is to be preferred the cutting disc 20 and the retaining disc 30 are fixed in the vertical direction. This is so that a well-defined cutting height is obtained.

Furthermore, the cutting disc 20 has circumferentially arranged, pointed teeth 21. The teeth together define the circumferentially extending cutting disc edge 22.

Each tooth 21 has an angular tip 23 in a plane perpendicular to said first axis of rotation 26. In the embodiment shown in Figures 3-6, said tip is located at a greatest radial distance from the center of rotation of the cutting disc 20. In the exemplary embodiment shown in Figures 3-6, the continuously extending cutting disc edge 22 is arcuate. Other types of design on teeth 21 and cutting edge edge 22 are also conceivable, see below.

As mentioned above, the cutting disc 20 has a cross-section in the form of a truncated cone and thus has a first cutting disc main surface 27 and a second cutting disc main surface 28 opposite the first cutting disc main surface 27 and a radially outer cutting disc side surface 29 connecting the first cutting disc main surface 28 to the second cutting disc main surface 27. Said cutting disc side surface 29 may, as in the embodiment shown in Figures 3-6, be grooved. In the embodiment shown, the grooves are a consequence of the method for producing the teeth 21 of the cutting disc 20 of the cutting disc 20.

The cutting disc edge 22 is defined by said first cutting disc main surface 27 and said cutting disc side surface 29. The cutting disc edge 22 has an acute edge angle, i.e. the edge angle is less than 90 °. Advantageously, said cutting disc edge 22 has an edge angle which is less than 45 °. In the embodiment shown in Figures 3-6, the abutment disc 30 comprises a first abutment disc head surface 37 and a second abutment disc head surface 38 opposite the first abutment disc head surface 38 and a radially outer abutment disc side surface 39 connecting the first abutment plate 38 to the second abutment plate.

The countertop side surface 39 is chamfered. The chamfer de nines a circumferentially extending abutment disk edge 32. The abutment disk edge 32 is pointed. Advantageously, said abutment disc edge 32 has an angle in the range 20-90 °.

Since both the cutting disc 20 and the abutment disc 30 have edges 22, 32 with acute edge angles, a well-defined nip 45 is obtained in which the cutting / cutting takes place and thus the cutting effect is better. The sharper the edges 22, 32, the better defined nip 45 is obtained and the better the cutting effect is obtained. However, the sharpness must be weighed against the service life of the respective edge 22, 32. The sharper the edge, the shorter the service life. For example. For example, the life of the retaining disc edge 32 can be extended by the bevel discussed above which results in the edge angle becoming less acute.

Since the abutment disk 30 includes this bevel, an abutment disk edge 32 is obtained with a larger edge angle than the edge angle of the abutment disk side surface 39.

Furthermore, the device 12 comprises a drive means 40 which are arranged for rotation of the abutment disc 30 and the cutting disc 20. The drive means 40 may be a motor, in particular an electric motor. Said drive means 40 are arranged to rotate the cutting disc 20 about the first axis of rotation 22 and the abutment disc 30 about the second axis of rotation 32. Said drive means 40 can rotate both the cutting disc 20 and the abutment disc 30 because their rotation shafts 22, 32 are linked to a first and a second gear 25. It will be appreciated, however, that the abutment disc 30 and the cutting disc 20, respectively, may be rotated by separate drive means.

The drive means 40 is arranged for rotation of the cutting disc 20 and the abutment disc 30 in opposite directions. The direction of movement of the cutting disc 20 10 15 20 25 30 35 531%; ÉÛÜ 10 and the abutment disc 30 where the two discs 20, 30 overlap are substantially the same as in the direction of movement of the packages 1 whose end closure 9 is to be removed. the feeding of the packaging web can take place intermittently, which leads to acceleration and deceleration of said web, so that the feeding speed is not constant. Alternatively, the packaging web can be fed continuously at a constant feed rate.

The peripheral speed of the cutting disc and the abutment disc should be slightly higher than or at least equal to the maximum feed speed. If continuous feed at a constant speed were to occur, the peripheral speed is slightly higher than or at least equal to this constant feed rate.

The peripheral speed of the cutting disc 20 and the abutment disc 30, respectively, should thus be slightly higher than the maximum feed speed of the packaging web. As a non-limiting example, the peripheral speed of the cutting disc 20 and the abutment disc 30, respectively, is 5-10% higher than the feed speed of the packaging web. This is because if the peripheral speed of the cutting disc 20 and the abutment disc 30, respectively, is the same or slower than the speed of the fed-in packaging web, the nip 45 creates a resistance. This in turn means that the height of the clip at the height of the package becomes uncontrolled. In order to obtain a clip that is controllable in height, the peripheral speed of the cutting disc 20 and the abutment disc 30, respectively, must be slightly higher than or at least equal to the maximum feed speed of the packaging web.

A typical feed rate of the packaging web is 0.5-2 m / s.

The package 1 whose end closure 9 is to be removed is fed towards the cutting nip 45 in a plane which is substantially parallel to said first and second axis of rotation 26, 36.

As a non-limiting example, it can be mentioned that the abutment disc 30 and the cutting disc 20, respectively, can be formed with a diameter in the range 40 to 80 mm. One way of selecting the diameter of the discs 20, 30 is that the diameter is chosen so that the peripheral speed of the cutting disc 20 and the abutment disc 30 at a rotational speed given by the drive means 40 slightly exceeds the feed speed of the packages 1 whose end closure 9 is to be removed. According to an actual embodiment, the cutting disc 20 and the abutment disc 30, respectively, were designed with a diameter of 60 mm. 10 15 20 25 30 35 'Il llu W W Cmt w * 11 Furthermore, it can also be mentioned, even now as a non-limiting example, that the abutment disc 30 and the cutting disc 20, respectively, can be formed with a thickness in the range 2 to 8 mm. According to an actual embodiment, the cutting disc 20 and the abutment disc 30, respectively, were designed with a thickness of 4 mm.

As a non-limiting example, it can also be mentioned that the number of teeth 21 per unit length of the cutting disc 20 is between 0.1 to 2 teeth per mm. In an actual embodiment, the cutting disc was designed with 72 teeth along the circumference of a disc with a diameter of 60 mm, ie about 0.4 teeth per mm.

Since the peripheral edge 22 of the cutting disc 20 is pointedly toothed, a snap-acting pulsating shear is produced when the end closure 9 is removed.

Experiments have shown that the removal of the end closure 9 of packages 1 made with the above-mentioned device 12 counteracts smearing of the packaging material and minimizes cold welding of the walls of the filling channel at the cut surface. Furthermore, it has also been found that small air pockets 50 arise between the two opposite side walls 6a, 6b of the package 1 when the end closure 9 is removed with the device according to the invention 12, see figure 7. These air pockets 50 occur in connection with the teeth 21 engaging the package 1. The air pockets 50 allow air to easily penetrate between the two opposite side walls 6a, 6b of the package 1 when these are separated.

One way of separating the side walls 6a, 6b of the package 1 is to provide a gripping means which first grips the two side walls of the package 1 by means of gripping arms provided with suction cups and then the gripping arms are moved apart to separate the side walls 6a, 6b of the package 1. The fact that air can easily flow into the package 1 thanks to said air pockets 50 when the side walls 6a, 6b of the package 1 are separated means that said separation of the sled walls 6a, Gb becomes much easier to perform. This together with the packaging material in the section across the side walls 6a, 6b of the package 1 is subjected to a reduced smearing and cold welding allows a simple and reliable opening of the channel 8 of the package 1 after the end closure 9 has been removed. In the above-described embodiment, the device 12 has been described with a cutting disc 20 with circumferentially arranged, pointed teeth 21, which teeth 21 together form a circumferentially extending wavy cutting disc edge 22. As mentioned above, other embodiments 12 of teeth 21 and of cutting edge eggs 22 conceivable. An example of an alternative design of teeth 21 and of cutting disc edge 22 can be found in Figure 8a. In this case, each tooth 21 has two, in a plane perpendicular to said first axis of rotation 26, opposite angular-forming tips 23a, 23b. Said tips 23a, 23b may have a curvature towards the center of the cutting disc 20.

Other examples of possible embodiments of teeth 21 are teeth 21 with shark fin shape, triangle shape, square shape, etc. Some possible designs of teeth 21 are illustrated in Figures 6, 8a-f.

It will thus be appreciated that the present invention is not limited to the embodiments described. Several modifications and variations are possible, which is why the scope of the present invention is defined exclusively by the following claims.

Claims (14)

10 15 20 25 30 5 l * al-a lll-Il lll-Ä Ü f: 1 3 PATENTKRAV Device for removing an end closure (9) of a package (1) of collapsing type, which end closure (9) closes a channel (8) delimited by two opposite side walls (Sa, Gb) of the package (1 ), the device comprising: a cutting disc (20) with circumferentially arranged, pointed teeth (21), which teeth (21) together form a circumferentially extending cutting disc edge (22), which cutting disc (20) is rotatably arranged around a first rotary shaft (26), and an abutment disc (30), which is rotatably arranged about a second axis of rotation (36), which is parallel to said first axis of rotation (26), which cutting disc (20) has a radially extending, peripheral cutting disc surface ( 24) which partially defines said cutting disc edge (22), and which abutment disc (30) has a radially extending abutment disc surface (34) facing said first cutting disc surface (24), characterized in that the cutting disc surface (24) and the abutment disc of the cutting disc (20) (30) mot retaining disc surface (34) are provided with an overlapping abutment to form a cutting nip (45). The device of claim 1, wherein each tooth (21) has an angular tip (23, 23a, 23b) in a plane perpendicular to said first axis of rotation (26). Device according to claim 2, wherein said tip (23, 23a, 23b) is located at a greatest distance from the center of rotation of the cutting disc (20). Device according to any one of claims 1-3, wherein at least one of the abutment disc (30) and the cutting disc (20) are biased in the axial direction towards the other of the abutment disc (30) and the cutting disc (20). A device according to any one of claims 1-4, wherein said abutment disc (30) comprises a circumferentially continuously extending abutment disc edge (32), and wherein said abutment disc surface (34) partially defines said abutment disc edge (32). 10 15 20 25 533 3GB 14 Device according to any one of claims 1-5, further comprising a drive means (40) arranged for rotation of at least one of the abutment disc (30) and the cutting disc (20). Device according to claim 6, wherein the drive means (40) is arranged for rotation of the cutting disc (20) and the abutment disc (30). Device according to claim 7, wherein the drive means (40) is arranged for rotation of the cutting disc (20) and the abutment disc (30) in opposite directions. Device according to any one of claims 1-8, wherein said cutting disc surface (24) and abutment disc surface (34) are complementary to allow said overlapping abutment. Device according to any one of claims 1-9, wherein said cutting disc edge (22) has an angle in the range 10-60 °. Device according to any one of claims 5-10, wherein said abutment disc edge (32) has an angle in the range 20-90 °. Device according to any one of claims 1-11, wherein the cutting disc (20) has a cross section with the shape of a truncated cone. Device according to claim 12, wherein the cutting disc (20) has a first cutting disc main surface (27) and a second cutting disc main surface (28) opposite the first cutting disc main surface (27) and a radially outer cutting disc side surface (29) connecting the first cutting disc main surface (27). with the second cutting disc main surface (28), and wherein said cutting disc side surface (29) is recessed. Device according to any one of claims 1-13, wherein the abutment disc (30) has a cross section with the shape of a truncated cone.