Apparatus for splicing a material web

Abstract

 The present invention relates to an apparatus for splicing a material web (2), which is paid off from a roll (1) such as packaging film web employed in liquid pouch packaging equipment, to a web (2') paid off from a new roll (1') when the web of the previous roll (1) is expiring, said apparatus comprising a splicing device (9) for making a splice between the web (2) of the expiring roll (1) and the web (2') of the new roll (1'), whereby the web (2, 2') being currently used is passed via said splicing device (9). The invention is implemented by having the apparatus equipped with support stands (10) for at least two rolls (1, 1') of which only one roll (1) is paid off at a time, further having the web tail (2') of the new roll (1') in the splicing device (9) threaded close to the web (2) of the previous, expiring roll (1), and finally having the apparatus provided with at least one sensor (14, 15) capable of detecting the expiration of the web (2) on the roll (1) being paid off and issuing a corresponding signal to said splicing device (9) that subsequently performs required splicing.

Description

[0001] The present invention relates to an apparatus for splicing a material web, which is paid off from a roll such as packaging film web employed in liquid pouch packaging equipment, to a material web to be paid off from a new roll when the web of the previous roll is expiring, said apparatus comprising a splicing device for making a splice between the web of the expiring roll and the web of the new roll, whereby the web being currently used is passed via said splicing device.

[0002] As referred to above, such apparatuses as the one disclosed herein are used in packaging equipment employed for, e.g., packaging liquid materials into plastic pouches. In such equipment a packaging film web is paid off from a roll typically located in the base of the equipment, the web is folded to form a pouch, the pouch bottom end is sealed liquid-tight, the pouch is filled with the desired liquid and the pouch top end is sealed and separated from the next pouch above in a single step, whereby a ready-packed pouch is formed. The film material typically is a polyolefin film such as polyethylene or a copolymer of polyethylene; alternatively also a polyamide film or similar material may be used.

[0003] The apparatus comprises a pay-off actuator, advantageously an electric motor adapted to actuate a pull roll, which is typically placed in the upper section of the packaging equipment, via a chain or belt drive, for instance. The pull roll pays off film from the roll at a preset speed. Next after leaving the pull roll, the film is taken via a buffering dancing roll set to the pouch-forming section. The purpose of the dancing roll set is to provide slack, or web reserve, in the film web so that pull devices located in the actual pouch-forming section can easily pull the web.

[0004] When the film roll is about to expire, a new roll must obviously be changed. The roll change operations include such steps as ejection of the core of the expired roll from its stand, insertion of the new roll in the stand and splicing of the end of the film web from the expired roll to the web tail of the new roll using a manual splicing device. Normally, such operations require stopping the equipment for the roll change, which obviously brings down the packaging capacity of the equipment thus causing unnecessary costs.

[0005] It is an object of the present invention to provide an apparatus capable of performing roll change without stopping the equipment. The apparatus according to the invention is characterized in that said apparatus has support stands for at least two rolls of which only one roll is paid off at a time, that in the splicing device of the apparatus the web tail of the new roll is threaded close to the film web of the previous, expiring roll, and that the apparatus is provided with at least one sensor capable of detecting the expiration of film on the roll being paid off and, correspondingly, issuing a signal to said splicing device which subsequently performs required splicing.

[0006] An embodiment of the invention is characterized in that the support stands for two rolls comprise elongated support beams at the opposite ends of the rolls, said beams being pivotally mounted at their center points so that the roll position can be changed over without removing the rolls from their stands.

[0007] Another embodiment of the invention is characterized in that the ends of the pivotal support beams are provided with open slots for the shafts of the rolls.

[0008] A still another embodiment of the invention is characterized in that to at least one of the pivotal support beams can be connected a link bar or similar member for the actuation of the rotary movement of the support beams and, thus, of roll changeover.

[0009] By virtue of the invention, the roll changeover can be performed automatically without the need for stopping the equipment for roll changeover. Obviously, a capacity increase of the packaging equipment is offered.

[0010] In the following, the invention will be described in greater detail with reference to the annexed drawings in which

Figure 1 is a diagrammatic side view of an apparatus according to the invention adapted to a piece of liquid pouch packaging equipment;

Figure 2 is a sectional view along line II-II in Fig. 1; and

Figure 3 is a sectional view along line III-III in Fig. 2.

[0011] Referring to Fig. 1, a portion of liquid pouch packaging equipment is shown. Therein, a roll paying off a packaging film web 2 is located in the base part of the equipment. The rolls 1 are paid off with the web being pulled by an pay-off actuator 3 such as an electric motor actuating via a chain or belt 4 the pull roll 5 exerting a pulling action on the film web 2. From the pull roll the film web is passed over a roll set 7 supported by a swinging arm 6 and, further, over corresponding rolls 8 of the equipment frame alternately to the actual pouch-forming section not shown in the diagrams. Such a pouch-forming section may be a part of any conventional packaging equipment using such a continuous web of packaging film as is discussed above. The purpose of the swinging arms 6, of which one is adapted to both ends of the roll set 7, is to provide a controllable buffer for the length of film reserve formed between the roll set 7 and the packaging equipment rolls 8. The swinging arms 6, of which one is shown in Fig. 1 in two different positions, are pivotally mounted at their one ends to the equipment frame, thus permitting the angle of the beams 6 and thereby the mutual distance between the roll set 7 and the rolls 8 to vary within certain limits. The length reserve of the film web is formed so that the pay-off actuator 3 is set to pull the film 2 slightly faster from the roll 1 than is consumed by the actual pouch packaging equipment. Then, with the increasing reserve length of the film, the swinging arm can rotate more and more downward until a preset lower limit is reached at which the pay-off actuator motor 3 is arranged to stop. Next, the reserve length is being consumed thereby rotating the arm 6 again upward until a preset upper limit is reached at which the motor is again started and the reserve length starts to increase, after which the cyclic operation will be repeated. While this represents conventional techniques, its explanation is considered necessary herein as the concept of reserve length is essential to the splicing function according to the invention.

[0012] In its passage between the pull roll 5 and the film roll 1, the film web 2 is passed via a splicing device 9, whose detailed structure will be described later with reference to Figs. 2 and 3.

[0013] In Fig. 1 is also illustrated a support beam 10 of the film roll 1 having a slot for the shaft 11 of the roll 1 made to one end of the beam and a corresponding slot made to the other end for the shaft 11' of the other roll 1'. The number of the support beams 10 is generally two (while only one is shown in diagrams), one beam at each end of the rolls 1, 1' and the beams may have an essentially identical design. Both of the support beams 10 are pivotally mounted at their center points to the equipment frame. For the rotation of the support beams 10, to at least one of the support beams is connected a detachable rotating link bar 13.

[0014] The rotation angle is 180 thus permitting positional changeover of the rolls 1 and 1'. Obviously, such rotation can be implemented with the help of a motor or similar actuator.

[0015] Additionally, the apparatus is equipped with two sensors 14 and 15, of which the sensor 14 utilizes a photocell, for instance, thus being able to issue a signal to a splicing device 9 immediately when the roll 1 runs out of film web 2 and the free end of the web has passed the sensor 14. In some rolls the trailing end of the web is adhered by, e.g., an adhesive to the roll core, whereby the web end will not leave the core when the film web expires from the roll. To guard against such a situation, another sensor 15 is adapted to detect the tensioning of the film web 2 in a conventional manner. Also this sensor can issue a signal to the splicing device 9 immediately when the web tension exceeds a preset limit.

[0016] Now referring to Figs. 2 and 3, the structure of the splicing device 9 is shown diagrammatically. Here, to a frame column 16 is attached a sealing member 19 on which a heatable sealing wire 20 is adapted in the manner shown in Fig. 2. To the frame column 16 are additionally connected two cylinders 21 having to their piston rods 22 connected a horizontal beam 17 arranged to perform a sealing swing when required actuated by the piston rods of the cylinder actuators 21, 22. To the horizontal beam 17 is attached in an easily detachable manner a counterpiece 18 for the heatable sealing wire so that between the counterpiece 18 and the horizontal beam 17 remains a gap through which the film web 2' of the new roll 1' is passed as shown in greater detail in Fig. 3. To the free end of the film web 2' is attached a weight 23 or other means serving to tighten or fix the film tail so as to assure its immobilization.

[0017] The function of the automatic splicing device according to the invention is as follows: the starting point is the situation shown in Figs. 1-3, wherein the film web 2 is being paid off from the roll 1. The free leading end of the film web 2' to be paid off from the next, new roll 1' is threaded in the manner shown in Figs. 2 and 3 past the gap between the sealing counterpiece 18 and the horizontal beam 17, and further over the counterpiece 18, after which in the illustrated embodiment a weight 23 is attached to the end of the film web. When the sensor 14 or the sensor 15 issues in the above-described manner a signal of film web expiration on the roll 1 to the splicing device 9 and its motor 3, the motor 3 is stopped and the splicing device 9 performs immediate splicing between the film web 2 and the new film web 2' in an operation where the horizontal beam 17 presses both the film web 2 and the film web 2' against each other between the members 18 and 19, whereby the heated sealing wire 20 heat-seals the film webs 2 and 2' to each other. Integrally mounted to the sealing device is a cutting device of conventional construction (not shown) that trims off the free ends of the spliced film webs. After completed splicing, the motor 3 is again started immediately. During splicing when the motor 3 is held stopped, the slack length of film web formed in the above-described manner provides sufficient material reserve for pouch packaging.

[0018] At the restart of the motor 3, the pull roll 5 commences to pull the film web 2' from the new roll 1'. At this moment the situation is such that the film web 2' travels via the gap between the members 17 and 18. Next, the counterpiece 18 is moved at a distance from the horizontal beam 17 so that the film web will be released from the nip between these members. Subsequently, the support beams 10 are rotated with the help of the rotating link bar 13 (Fig. 1) or using a motorized actuator about the pivot point 12 by 180 so that the new roll 2' will be changed over to the left in Fig. 1, while the core of the expired roll will be moved to the right. Now the roll core can be removed from the slots of the support beams and a new roll inserted thereto. The counterpiece 18 is attached back to the splicing device 9 and the free end of the new roll is again threaded in the manner shown in Fig. 3 through the gap between the members 17 and 18 to wait for the next splicing operation. Finally, the rotating link bar can be detached and reconnected to the right-side connection point shown in Fig. 1. Thus, the completed splicing sequence has restored the situation shown in the diagrams. The entire sequence will be repeated when the film web again expires from the roll being paid off. Most of the above-described steps can be performed in a freely varied order.

[0019] To a person versed in the art, it is obvious that the invention is not limited by the above-described exemplifying embodiments, but rather may be varied within the scope and spirit of the annexed claims. Hence, it is possible to vary the construction of the exemplifying embodiment on many of its details as required. The essential property, however, in the splicing device is to have a detachable member, because otherwise the new film web cannot be guided in the desired manner without stopping the pouch packaging equipment. Additionally, it is particularly advantageous to have the position changeover of the rolls made easy using, e.g., the pivotal support beam arrangement illustrated in the drawings and capable of providing the above-described function.

Claims

1. An apparatus for splicing a material web (2), which is paid off from a roll (1) such as packaging film web employed in liquid pouch packaging equipment, to a material web (2') to be paid off from a new roll (1') when the web of the previous roll (1) is expiring, said apparatus comprising a splicing device (9) for making a splice between the web (2) of the expiring roll (1) and the web (2') of the new roll (1'), whereby the web (2, 2') being currently used is passed via said splicing device (9), characterized in that

- said apparatus has support stands (10) for at least two rolls (1, 1') of which only one roll (1) is paid off at a time,

- the web tail (2') of the new roll (1') is threaded in the splicing device (9) close to the web (2) of the previous, expiring roll (1), and

- the apparatus is provided with at least one sensor (14, 15) capable of detecting the expiration of the web (2) on the roll (1) being paid off and issuing a corresponding signal to said splicing device (9) that subsequently performs required splicing.

2. An apparatus as defined in claim 1, characterized in that the support stands (10) for two rolls (1, 1') comprise elongated support beams at the opposite ends of the rolls, said beams being pivotally mounted at their center points (12) so that the position of the rolls (1, 1') can be changed over without removing the rolls from their stands.

3. An apparatus as defined in claim 2, characterized in that the ends of the pivotal support beams (10) are provided with open slots for the shafts (11, 11') of the rolls (1, 1').

4. An apparatus as defined in claim 2 or 3, characterized in that to at least one of the pivotal support beams (10) can be connected a link bar (13) or similar member for the actuation of the rotary movement of the support beams (10) and, thus, the rotating changeover movement of rolls (1, 1').

5. An apparatus as defined in any of claims 1-4, characterized in that said splicing device (9) is comprised in a conventional manner of against each other compressible members (18, 19) suited to perform splicing in the gap remaining between said members and of which members at least one (18) is easily detachable for threading the spliced web (2') over its proper path.

6. An apparatus as defined in any of claims 1-5, characterized in that one sensor (14) for detecting the expiration of the web (2) is adapted close to the roll (1), said sensor utilizing a photocell, for instance, and that the apparatus further includes another sensor (15) capable of detecting the tensioning of the web (2) if the trailing end of the web is adhered to the roll core.

Drawing