EP1157929B1 - Method and device for applying an outer head cover on a roll of web material to be packaged - Google Patents

Description

The invention relates to a method for attaching an outer end cover to a material web roll to be packaged, in which the outer end cover is made tacky by heating and brought to bear against the end face of the material web. Furthermore, the invention relates to a device for attaching outer end caps to a web roll to be packaged with at least one end cover stack with end caps, which are provided on one side with heat-activatable adhesive, and a gripping device which is movable over the end cover stack.

The invention will be described below with reference to a roll of paper to be packaged, but without being limited thereto. It is also applicable to comparable rolls that are packed in a similar way.

In one of the last manufacturing steps, paper webs, after being cut to the correct width, are wound up into paper rolls. They must be packed before being transported to a consumer. For this purpose, in each case a so-called inner end cover is usually attached to the end faces of the paper roll. Thereafter, the circumference of the paper roll is wrapped with a packaging web, which usually protrudes slightly beyond the end faces. This projection is taken when wrapping or later on the front pages. Thereafter, an outer end cover is glued to each end face. For this purpose one often uses end caps, which are provided with a heat-activatable adhesive, a so-called hot-melt adhesive. The outer end covers are placed with their adhesive-free side on a packing press plate. The packing press plate is heated. The heat penetrates the outer face cap and makes the glue sticky. At the same time or offset in time, the packing press plate presses the outer end cover against the end face of the paper roll and thus glued the outer end cover with the inner end cover and the folded supernatants of the packaging web.

Such a procedure is known, for example, from EP 0 088 558 A1. The front cover is firmly sucked on a press plate. The press plate moves to the front side of the web roll to be packaged. It is heated so that the hot melt adhesive adheres to the front cover on the front side of the web roll.

This procedure has basically proven itself. It produces relatively stable packaging that protects the web rolls. However, this type of packaging is time consuming and energy consuming. It is not only necessary to heat the outer end cover, but the entire press plate, which takes a certain amount of time and consumes relatively much energy.

US 5 761 881 A shows another type of packaging. Here, the web roll is wrapped with a packaging web whose width corresponds to the axial length of the web roll. At the end faces end caps are fixed, whose diameter is greater than the diameter of the web roll. The front cover has at its periphery a plurality of incisions, so that tabs arise, which are bent over the outer periphery of the web roll to be packaged and glued there. These tabs can be provided with a heat-activated adhesive, which is activated when folding the tabs. To apply the heat required for this purpose, for example, a heating roller, warm air or a heat radiator can be used.

The invention has for its object to reduce energy consumption.

This object is achieved in a method of the type mentioned above in that the outer end cover is heated contactless on the way between a receiving position and a position in front of the front side of its adhesive side by passing it past a heater.

This eliminates the need to heat the entire press plate. It is heated only the outer end cover and there even only the part that is to be made sticky later, namely the adhesive. It will not be absent that the outer end cover itself is heated. However, this heat does not have to pass through the outer end cover because it is fed contactlessly from the adhesive side. Since one carries out the heating on the way between a receiving position and a position in front of the front side, one is relatively free in the choice of the heater. Since you already heated the outer end cover on the way from a receiving position to the position in front of the web roll, the outer end cover can be brought directly to the front end to the plant without removing after heating the heater from the space between the outer end cover and the front page is required. This saves time. The term adhesive is to be understood here broadly. By "adhesive" is meant all materials which become tacky at elevated temperature and, after cooling, cause a connection of the front cover and end face. Thus, the adhesive may also be a plastic coating of the end cover, for example made of polyethylene (PE). Although the PE layer should be in the first Line act as a "vapor barrier". However, as it begins to melt and become tacky at around 110 ° C, it can also be used as a heat-activatable adhesive. By passing the outer end cap past a heater saves time again. The heating then takes place during transport of the front cover, which is required anyway.

Preferably, two end covers are taken in succession and transported together. For receiving the outer end cover, which are also referred to below as the front cover, one usually uses a gripping device. This gripping device must cover the path between the receiving position and the web roll to be packaged. If she already wears two end covers, she only needs to be driven halfway.

Preferably, the outer end cap is centered prior to heating. If you remove the front cover of a stack, is not readily ensured that the end cover then has the correct orientation with respect to the end face of the web roll. It is known to center the end cover. By providing this centering prior to the heating step, one can more effectively effect the heating of the adhesive, that is, one need not spend more heating energy than is absolutely necessary, and yet be assured of hitting the entire adhesive surface of the end cover ,

It is preferred that the outer end cover is picked up by a lid stack is placed on a centering on which it can slide against centering stops and the Außenstirndekkel is then resumed. One thus temporarily triggers the engagement between the end cover and the gripping device by allowing the end cover to slide against centering stops. This is a relative one simple and fast action that can be accomplished without additional measurements.

Preferably, the end covers are centered sequentially. If you transport the two end covers together, they also get together on the centering device. It also saves time by centering the end covers one after another, but before they move on.

Preferably, an outer end cover is first heated and attached to the web roll and then heated the other outer end cover and attached to the web roll. The heat-activatable adhesive must not sink below a predetermined temperature between heating and application to the face. In this case, he would lose his adhesiveness again. For this reason, it is expedient to handle individually again from the step of heating to each end cover.

Preferably, the heat emission is limited to the surface of the outer end cover. This not only saves energy, but also reduces potential hazards. Heat energy then does not pass the front cover and thus can not damage any components.

Preferably, the outer face cap is brought into abutment with the face within 10 seconds of the end of the heating. This time is so short that the heat-activatable adhesive remains sticky.

Preferably, IR radiation is used for heating. Infrared radiation enables problem-free transport of the required heating energy. It is ready relatively quickly, so usually does not require longer preheat times.

The invention is achieved in a device of the type mentioned above in that a heating device is provided which acts contactlessly on the adhesive-provided side of the outer end cover and in that the gripping device is movable past the heating device.

The heater is thus positioned adjacent (i.e., laterally, above, or below) a travel path that the gripper travels on its way from the end cap stack to the face of the web roll. Of course, the gripper may also remain in front of the heater to heat the adhesive layer, if necessary. Since the heating device is arranged next to the movement path of the gripping device, it is possible to fasten the outer end cover directly to the end faces of the material web roll with the aid of the gripping device. So it is not necessary to re-implement the front cover on press plates or the like.

Preferably, a centering unit is provided which can be approached between receiving an outer end cover and the heating. This centering device causes two things. On the one hand, the outer end cover is related centered on the roll of web material, so that it can be positioned there relatively accurately. On the other hand, it is also centered with respect to the heater, so that the heater does not have to irradiate more surface than is required.

Preferably, the gripping device has two gripping heads. In this case, the gripping device can transport two end covers from the end cover stack to the material web roll.

Preferably, the gripping heads are arranged offset by 180 degrees to each other. You can thus record both end caps in the same way. The gripping device is lowered onto the end cover stack and can grasp the first end cover. Thereafter, it is rotated 180 degrees and lowered again onto the end cap stack to receive the second end cap. The two end covers can then be transported together.

Preferably, the gripping device has surface-acting pressure means. You can then use the gripping device to press the end cover on the front side of the web roll. The gripping device thus receives a further, beyond the pure gripping and transporting task.

The heating device preferably has a plurality of individually activatable heating elements. These heating elements can then be switched on or activated individually to heat certain areas of the end cover. It is conceivable, for example, that the heating elements are formed as rings, which are arranged concentrically or in another way so that one depending on must turn on the diameter of the front side in each case only a predetermined number of heating elements. It is also conceivable that the heating elements are arranged in a row next to each other, wherein when passing the front cover always only the heating elements are activated, which are covered at a certain time by the outer end cover.

Since the heater acts contactless, avoid contamination of the heating elements by the adhesive. In addition, lower requirements are placed on the positioning accuracy of the end cover relative to the heater.

It is particularly preferred that the heater has IR emitters. Infrared radiation, as stated above, is a particularly effective form of heat transfer.

Fig. 1

eine schematische Draufsicht auf eine Vorrichtung zum Anbringen von Außenstirndeckeln an eine Materialbahnrolle,

Fig. 2

eine vergrößerte schematische Ansicht einer Greifeinrichtung und

Fig. 3

eine perspektivische Ansicht der Vorrichtung.

The invention will be described below with reference to a preferred embodiment in conjunction with the drawings. Herein show:

Fig. 1

a schematic plan view of an apparatus for attaching outer end caps to a web roll,

Fig. 2

an enlarged schematic view of a gripping device and

Fig. 3

a perspective view of the device.

FIG. 1 shows a device 1 for attaching outer end covers to a packed web roll 2, for example a paper roll. The web roll is already provided in a conventional manner with a peripheral packaging, wherein axial projections of the peripheral packaging on the end faces 3, 4 of the web roll 2 are folded. Optionally, an inner end cover may have been applied to the end faces 3, 4 before folding the supernatants. The web roll 2 rests on support rollers 5, 6, which may optionally also be used as a means of transport.

The diameter and the axial length of the web rolls may vary from roll to roll. In order to be able to select an outer end cover of suitable size, the outer end covers are arranged on stacks 7a-7e, on which outer end covers (hereinafter referred to briefly as end covers) 7 are kept in stock. The stacks 7a-7e are arranged approximately on a circular line which is formed around a stand 8 of a gripping device 9. The gripping device has a telescopic arm 10 with a plurality of joints 11, 12, wherein the outermost end of the arm 10 is still rotatable about the axis of the arm, as should be symbolized in Figure 2 by an arrow 13. The joints 11, 12 are shown by way of example only. If necessary, even more joints can be provided. At the end of the arm 10, a gripping mechanism 14 is arranged. This gripping mechanism 14 is movable by means of the arm 10 and the stator 8, which can be rotated in the direction of arrow 15, in virtually any position within the device. In particular, it can be moved over the individual end cover stack 7a-7e. The stand 8 is height-adjustable, so that the gripping mechanism 14 can each be lowered onto the uppermost end cover of a stack 7a-7e in order to grasp an end cover 7 located there. However, the gripping mechanism 14 can also be moved so that it brings a front cover 7 on the end faces 3, 4 of the web roll 2 to the plant.

Also on the circular path 16, a centering device 17 is arranged, which has an inclined plane 18, at the lower end of which a prism 19 is located.

In addition to the centering device, a heating device 20 is arranged, which has a plurality of individually activatable heating elements 21, which are designed as infrared radiators.

Figure 3 shows the same arrangement in a schematic perspective view. Identical parts are provided with the same reference numerals. For attaching an end cover 7 to the web roll 3, which is already provided with inner end covers and has a peripheral packaging, the device 1 operates as follows:

The gripping mechanism 14 of the gripping device 9 is pivoted over those of the end cover stack 7a-7e, whose end cover has one of the roll 2 to be packed corresponding diameter. Here, the diameter of web roll 2 and end cover 7 do not have to match exactly. The front cover 7 may be slightly smaller.

The gripping device 9 lowers the gripping mechanism 14 on the stack 7a-7e and takes over the top cover 7. Then, the gripping mechanism 14 is raised again, thereby pivoted 180 degrees in the direction of arrow 13 and lowered to take over a second end cover 7 again.

For this purpose, the gripping mechanism 14 on a first gripping head 22 and a second gripping head 23, which are arranged mirror-symmetrical to each other. Each gripping head 22, 23 has a predetermined number of suction cups 24, which can be placed under negative pressure to hold the end cover 7. Between the suction cups 24 pressure pads 25 are arranged, whose function will be described later. The necessary for the supply of the suction cups 24 and the pressure pad 25 pneumatic lines are not shown for reasons of clarity.

When the gripping mechanism 14 has received the two end covers 7, pivots the arm 10, which has been set for this course to the appropriate length, on the centering device 7, ie the inclined plane 18, at the lower end, the prism 19 is located. Here, first, the lower end cover is dropped. He then slips on the inclined plane 18 in the prism 19, whereby it is centered. The lid thus centered is then picked up again by the gripping head 22. The gripping head 22 is in this case positioned so that the recorded end cover 7 can later be brought to bear centrally on the end faces 3, 4 of the web roll 2. The relevant data are available via a control device, not shown.

After the first end cover has been centered, it is raised again and the gripping mechanism 14 is rotated 180 degrees to center the second end cover in the same way.

Thereafter, the gripping mechanism 14 passes over the heater 20. The coated bottom of the first, i. lower end cap plasticized, so made sticky, so that it can be applied by the gripping mechanism 14 to the first end face 3 of the material web roll 2 to be packaged. Here, the pressure pad 25 are inflated, so that the end cover 7 can be pressed flat against the end face 3. Since the underside of the end cover 7 (in Figure 2, these are the outer sides of the end cover 7) heated by the heater 20 and thus made tacky, the connection of the end cover 7 takes place with the web roll 2 during cooling.

Once the first end cover has been secured to the end face 3, the gripping mechanism 14 moves back to the heater 20 and makes in the same way the underside of the second end cover 7 sticky.

The individual heating elements 21 of the heater 20 can be controlled individually, so that only those heating elements are always active, which are just covered by a front cover 7. The heating elements 21 may be formed, for example, as infrared radiators, which are activated or deactivated by switching on and off of a stream. Thus, there is no danger that radiation directed past a face cap sets any other parts of the device on fire.

The second end cover is then applied to the other end face 4 of the web roll and pressed surface by means of the pressure pockets 25.

A conventional packing press is not required in this embodiment. The energy needed to tackify the outer end cover 7 is relatively low. The gripping device 9, which can be realized by means of a known industrial robots, allows the front cover relatively quickly from the heater 20 to the end faces 3, 4 to transport, so that it can be sure that the end cover 7 are still sticky when they are brought to the end faces 3, 4 of the web roll to the plant.

Instead of the illustrated quasi-line arrangement of the heating elements 21 can also provide that the heating elements are formed as concentric rings, the gripping mechanism 14, the corresponding end cover 7 then positioned centrally on the heater. Here, the gripping mechanism 14 must remain for a short time in front of the heater to heat the adhesive side of the end cover, other configurations are also possible, for example, the respective end cover can be heated with hot air.

The concrete design of the heater depends on the adhesive used. If the time required for the end cap to become sticky is relatively long, training may be advisable in which the gripping mechanism remains in front of the heater. you but can also provide that the gripping mechanism 14 reciprocates the front cover before the heater.

Claims (16)

1. Method for applying an outer end cover (7) to a roll of web material (2) to be packaged, in which the outer end cover (7) is made tacky by heating and is brought into contact with the end (3, 4) of the material web, characterized in that, on the way between a pick-up position and a position in front of the end (3, 4), the outer end cover (7) is heated without contact from its side provided with adhesive by being led past a heating device (20).
2. Method according to Claim 1, characterized in that two outer end covers (7) are picked up one after the other and transported onward together.
3. Method according to Claim 1 or 2, characterized in that the outer end cover (7) is centred before being heated.
4. Method according to Claim 3, characterized in that the outer end cover (7) is picked up from a cover stack (7a - 7e), deposited on a centring device (17), on which it is allowed to slip against centring stops (19), and the outer end cover (7) is then picked up again.
5. Method according to Claim 3 or 4, characterized in that the outer end covers (7) are centred one after another.
6. Method according to one of Claims 2 to 5, characterized in that firstly one outer end cover (7) is heated and fixed to the roll of web material (2), and then the other outer end cover (7) is heated and fixed to the roll of web material (2).
7. Method according to one of Claims 1 to 6, characterized in that the discharge of heat onto the surface of the outer end cover (7) is limited.
8. Method according to one of Claims 1 to 7, characterized in that the outer end cover (7) is brought into contact with the end (3, 4) within 10 seconds after the end of the heating.
9. Method according to one of Claims 1 to 8, characterized in that IR radiation is used for heating.
10. Device for applying outer end covers (7) to a roll of web material (2) to be packaged, having at least one end cover stack (7a - 7e) with end covers (7), which are provided on one side with adhesive that can be activated by heat, and a gripping device (9), which can be moved over the end cover stack (7a - 7e), characterized in that a heating device (20) is provided which acts without contact on the side of the outer end cover (7) provided with adhesive, and in that the gripping device (9) can be moved past the heating device (20).
11. Device according to Claim 10, characterized in that a centring device (17) is provided which can be moved between picking up an outer end cover (7) and the heating.
12. Device according to Claims 10 and 11, characterized in that the gripping device (9) has two gripping heads (22, 23).
13. Device according to Claim 12, characterized in that the gripping heads (22, 23) are arranged to be offset by 180 degrees in relation to each other.
14. Device according to one of Claims 10 to 13, characterized in that the gripping device (9) has pressing means (25) that act flatly.
15. Device according to one of Claims 10 to 14, characterized in that the heating device (20) has a plurality of heating elements (21) that can be activated individually.
16. Device according to one of Claims 10 to 15, characterized in that the heating device (20) has IR radiant heaters.

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