EP4620664A1

EP4620664A1 - Group for applying a zip closure strip on a long pasta bag

Info

Publication number: EP4620664A1
Application number: EP25164379.7A
Authority: EP
Inventors: Giuseppe VEZZANI
Original assignee: Altopack SpA
Current assignee: Altopack SpA
Priority date: 2024-03-19
Filing date: 2025-03-18
Publication date: 2025-09-24

Abstract

A zip group (2), for long pasta packaging machine (1), able to apply a zip closure strip (3) on a plastic film (4) suitable for making bags to accommodate doses of long pasta, is described. The zip group (2) provides a zip application device (40) comprising a reel (50) of a zip closure tape (3), a rotor (7) able to feed a defined length of zip closure strip (3) for application on the plastic film (4), a sealing bar (8) for applying the zip closure strip (3) on the plastic film (4), feeding and cutting means (5) of the zip closure tape (3) to define the zip closure strip (3) for the rotor (7), and suction means (6) of the zip closure strip (3) on the rotor (7). The zip group (2) also includes a first oscillating frame (9) upstream of the rotor (7), a second oscillating frame (10) downstream of the rotor (7), a guide frame (30) above the second oscillating frame (10), and blocking and actuating means (23) of the plastic film (4) downstream of the rotor (7) and upstream of the second oscillating frame (10).

Description

The present invention relates to a group for applying a zip closure strip on a long pasta bag.
The pasta industry, a product now found worldwide, is called to meet several packaging needs.
Long pasta requires particular attention because it is more difficult to handle, and therefore more subject to breaking.
Machines for packaging long pasta have been proposed, which provide the horizontal insertion of doses of long pasta into a plastic material casing being formed, which is advanced by a conveyor belt along a horizontal path where, once a dose of pasta is received, its flaps are progressively folded and joined to each other to form a closed tubular casing around the pasta itself. As shown in granted Italian Patent No. 102016000059196 of the present Applicant, the longitudinal closure of the casing is made permanent by a mutual longitudinal sealing of the two flaps performed at the end of the folding and joining operation.
The long pasta dosing step is very important in packaging machines. The present Applicant is also the holder of European Patent EP-3142927B1 describing a dosing machine comprising a three-compartment rotor able to feed two load cells in series.
It is therefore understood that the long pasta is usually contained in tubular shape plastic film bags closed at the head and bottom by sealing.
However, once it is opened at the head, the bag requires external means, for example a common clip, to be reclosed, moreover without any guarantee of effective closure. The clip may accidentally be released from the head of the bag, with the risk of the long pasta coming out of the bag.
Solutions are known providing the application of a zip closure on the plastic film for making a tubular bag.
A zip closure means a closure consisting of two strips of plastic material, each provided with at least one groove and one protrusion complementary to the groove, in which the protrusion of one strip is suitable for snap coupling, by pressure, with the groove of the other strip. In the case of tubular shape bags for long pasta, generally a single zip closure strip provided with at least one groove and one protrusion is applied, the subsequent formation of the plastic film tube defining two stretches of the same plastic material strip suitable for being coupled to transversely close a bag.
For example, EP-1737311 shows a rotor with grooves provided with slides for zip closure strips, and EP-1186404 describes a suction rotor.
Disadvantageously, to apply the zip closure strip, there is a need to block the sliding of the plastic film in the forming tube downstream of the application group of the zip closure strip.
Consequently, the production undergoes intermittent stops, increasing the packaging times.
WO-99/03672 describes a zip group for applying a zip closure strip on a plastic film, comprising two oscillating frames and two pairs of drive rollers for blocking the plastic film for the application of the zip closure strip.
Unfortunately, it is difficult to synchronize the deactivation of the two pairs of drive rollers to block the plastic film while keeping it taut to achieve a quality application of the zip closure strip.
It is the object of the present invention to make a group for applying a zip closure strip on a long pasta bag, for a packaging machine able to continuously form and fill bags for long pasta.
It is a further object of the present invention that said group for applying a zip closure strip is simply associable with known packaging machines able to continuously form and fill bags for long pasta.
It is yet a further object of the present invention that the application of the zip closure strip does not jeopardize the quality of the bag obtained at the end of the process.
According to the invention, said and further objects are achieved by a zip group as defined in claim 1.
Advantageously, the oscillating frames compensate for the blocking of the plastic film for applying the zip closure strip on the plastic film.
In particular, the first oscillating frame accumulates plastic film in braking step by rotating downwards and releases the plastic film in acceleration step by rotating upwards. The second oscillating frame rotates upwards to recover plastic film with the zip closure strip already applied when the portion of plastic film between the sealing bar and the rotor is stopped for application of the zip closure strip. When the motion of the plastic film between the sealing bar and the rotor resumes, the second oscillating frame rotates downwards to compensate for the plastic film fed in excess with respect to what is needed to keep constant and continuous the motion of the plastic film with the zip closure strip applied downstream of the zip group.
Advantageously, the zip group according to the present invention is associable with known packaging machines without zip groups, before the plastic film tube forming station, after the plastic film is unrolled from its reel. The packaging machine with the zip group is efficient and highly productive.
These and other features of the present invention will become more apparent from the following detailed description of a practical embodiment thereof, shown by way of non-limiting example in the accompanying drawings, in which:

Figure 1 shows a side view of a long pasta packaging machine;
Figure 2 shows a top plan view of the packaging machine;
Figure 3 shows an enlarged side view of a zip group of the packaging machine, in a first configuration;
Figure 4 shows an enlarged side view of the zip group, in a second configuration;
Figure 5 shows a top plan view of the zip group, in the first configuration.

A packaging machine 1 for the continuous production of tubular shape plastic film bags filled with doses of long pasta includes a dosing station preferably with at least one rotor able to feed load cells, a station for forming a plastic film tube, a station for the periodic insertion of doses of long pasta into the plastic film tube, and a sealing and cutting station of the plastic film tube filled with doses of long pasta to obtain a plurality of tubular shape plastic film bags with defined doses of long pasta to be sold.
Examples of stations for dosing, forming the plastic film tube, periodic insertion of doses of long pasta, and sealing and cutting stations comprised in the packaging machine 1 are described in EP-3142927B1 , in granted Italian Patent No. 102016000059196 , both already mentioned above, and in granted Italian Patent No. 202020000001588 of the present Applicant.
The packaging machine 1 further comprises a zip group 2 able to apply a zip closure strip 3 on a plastic film 4, located upstream of the plastic film tube forming station.
Zip closure 3 means a closure consisting of two strips of plastic material, each provided with at least one groove and one protrusion complementary to the groove, in which the protrusion of one strip is suitable for being snap coupled by pressure with the groove of the other strip. As will become more apparent below, the zip group 2 of the present invention applies a single zip closure strip 3 provided with at least one groove and one protrusion, the subsequent formation of the plastic film tube defining two stretches of the same strip of plastic material suitable for being coupled to transversely close a bag.
The zip group 2 provides a zip application device 40 comprising a reel 50 of a zip closure tape 3, a rotor 7 able to feed a defined length of zip closure strip 3 for application on the plastic film 4, a sealing bar 8 for applying the zip closure strip 3 on the plastic film 4, feeding and cutting means 5 of the zip closure tape 3 to define said zip closure strip 3 for rotor 7, and suction means 6 of the zip closure strip 3 on rotor 7.
The zip group 2 further comprises a first oscillating frame 9 upstream of rotor 7 and a second oscillating frame 10 downstream of rotor 7.
The first oscillating frame 9 comprises two parallel arms 11 between which two rollers 12 rotatably fixed to said parallel arms 11 extend. The rollers 12 have an axis of rotation orthogonal to the direction of development of the parallel arms 11 and to the sliding direction of the plastic film 4, a space being provided between the two rollers 12 so as to allow the passage of the plastic film 4. At least two rollers 12 need to be provided, possibly more than two rollers 12 if the accelerations/decelerations of the plastic film 4 require it, as will become more apparent below.
The parallel arms 11, at a constrained end 13, are associated with a bar 14 parallel to the rollers 12 so that the parallel arms 11 can only rotate around a first oscillation axis 17 corresponding to the axis of bar 14, i.e., no other rotary or translation movements are allowed because bar 14 is integral with two uprights 15 fixed to the base frame 16 of the packaging machine 1.
Said constrained ends 13 of the parallel arms 11 embrace bar 14 and are free to rotate around said first axis of oscillation 17, sliding on bar 14.
The oscillation of the first oscillating frame 9 is actuated by the movement of the plastic film 4, as will become more apparent below.
The second oscillating frame 10 comprises two parallel arms 18 between which rollers 19 extends, preferably three rollers 19, which are rotatably fixed to said parallel arms 18. The rollers 19 have axis of rotation orthogonal to the sliding direction of the plastic film 4, a space being provided between consecutive rollers 19 so as to allow the passage of the plastic film 4. The rollers 19 are parallel to the rollers 12. The number of rollers 19 may vary according to the accelerations/decelerations of the plastic film 4, as will become more apparent below.
The parallel arms 18, at the respective constrained ends 22, are associated with pins so that the parallel arms 18 can rotate around a second axis of oscillation 20 corresponding to the axes of the pins, i.e., no other rotary or translational movements are allowed because the pins are integral with the uprights 15.
Said constrained ends 22 of the parallel arms 18 embrace the respective pins and are free to rotate around said second axis of oscillation 20, sliding on the pins.
The oscillation of the second oscillating frame 10 is actuated by a pneumatic piston 35 comprising a cylinder 36 rotatably fixed to a guide frame 30 located above the second oscillating frame 10, and a stem 37 sliding in cylinder 36 and having one end, external to cylinder 36, rotatably fixed to a free end 38 of the parallel arms 18 of the second oscillating frame 10.
The guide frame 30 comprises two arms 31 integral with the uprights 15 and a plurality of rollers 32, parallel to the rollers 19, preferably four rollers 32. The arms 31 are preferably horizontal, the plastic film 4 sliding between the rollers 32. The number of rollers 32 varies according to the number of rollers 19 of the second oscillating frame 10.
There preferably is provided, below the second oscillating frame 10, a guide roller 33 parallel to the rollers 32 and fixed to the uprights 15 by means of arms parallel to the arms 31 of the guide frame 30.
The zip group 2 further comprises blocking and actuating means 23 of the plastic film 4 downstream of rotor 7 and upstream of the second oscillating frame 10.
The blocking and actuating means 23 comprises at least one friction element 24, preferably cylindrical in shape, and a blocking and actuating cylinder 25 below the friction element 24 at a variable distance. The outer surface of the blocking and actuating cylinder 25 is made of rubbery material to promote the fraction with the plastic film 4.
The friction element 24 is fixed because it is integral with a bar 26, parallel to the rollers 12, 19, and integral with the uprights 15.
The blocking and actuating cylinder 25, parallel to bar 26, is fixed to a bar associated with the uprights 15 so as to be able to translate vertically between a motion position of the plastic film 4 and a blocking position of the plastic film 4.
The blocking and actuating cylinder 25 is further able to rotate around a drive shaft 70 coincident with the axis of the blocking and actuating cylinder 25 upon actuation of a brushless type motor 71.
The vertical translational movement of bar 26, i.e., of the blocking and actuating cylinder 25, is actuated by pneumatic means, for example, pneumatic pistons 28 fixed to side extensions 29 of the uprights 15.
In the motion position, there is, between the friction element 24 and the blocking and actuating cylinder 25, a space useful for the movement of the plastic film 4 which is moved by friction with the rubbery outer surface of the blocking and actuating cylinder 25.
In the blocking position, the blocking and actuating cylinder 25 is blocked from rotation and is forced by translation against the friction element 24, canceling said space and blocking by friction the sliding of the plastic film 4. Even if motor 71 is deactivated, there could be movements of the plastic film 4 due, for example, to the oscillating frames 9, 10, for applying a zip closure strip 3 by means of the sealing bar 8 since a complete and safe blocking of the plastic film 4 is required.
The blocking and actuating cylinder 25 is in fact a drive roller which, thanks to the possibility of translating towards the friction element 24, is able not only to move the plastic film 4 but also to effectively block it in combination with the friction element 24 for the application of the zip closure strip 3.
The zip application device 40 further comprises means able to actuate the rotation of rotor 7 according to a non-continuous angular step, each step corresponding to the application of a zip closure strip 3 on the plastic film 4 by the sealing bar 8 able to move orthogonally to the sliding direction of the plastic film 4, i.e., towards the plastic film 4 or away from it. Said actuation means of the rotation of rotor 7 consist, for example, of a brushless type motor 60.
Operatively, the zip group 2 works so as to keep a continuous motion of the plastic film 4 downstream of the zip group 2.
In greater detail, with particular reference to Figures 3 and 4, the plastic film 4 enters the zip group 2 at the first oscillating frame 9.
When the blocking and actuating cylinder 25 is actuated to interact with the friction element 24, thus blocking the sliding of the plastic film 4, the first oscillating frame 9 rotates downwards to recover the plastic film 4 in excess up to taking the configuration shown in Figure 3.
Once the plastic film 4 is blocked, the sealing bar 8 moves towards rotor 7, or better towards the plastic film 4 stopped between rotor 7 and the sealing bar 8, applying the zip closure strip 3 on the plastic film 4.
Prior to the application of the zip closure strip 3, rotor 7 was caused to rotate so as to position a zip closure strip 3 in front of the plastic film 4.
The zip closure strip 3 is withheld by rotor 7 by suction means 6, and previously cut from the tape, unwound from reel 50 and blocked for cutting.
Rotor 7 preferably provides four seats 80 for zip closure strips 3, i.e., it is able to rotate by 90° for each step. Obviously, the number of seats 80 may vary based on production needs.
As shown in Figure 3, when the plastic film 4 is blocked, simultaneously to the downwards rotation of the first oscillating frame 9, an upwards rotation of the second oscillating frame 10 occurs so as to recover the plastic film 4 to ensure the continuity of the motion of the plastic film 4 downstream of the zip group 2.
A control unit coordinates the actuators of the pneumatic piston 35 able to control the rotation of the second oscillating frame 10, of the blocking and actuating cylinder 25 able to block the plastic film 4 together with the friction element 24 and give the plastic film 4 movement again once there is no more blocking, of the rotating step motor 7, of the sealing bar 8 translating towards rotor 7 and away from it, of the suction means 6 of the zip closure strip 3, of the feeding and cutting means 5 of the zip closure tape 3.
The feeding and cutting means 5 of the zip closure tape 3 comprise a motor which drags the zip closure tape 3, unwinding it from reel 50, blocking means of the zip closure tape 3 to keep it in position after the cutting, cutting means of the zip closure tape 3 to obtain a defined length of zip closure strip 3 which is sucked in a seat 80 of rotor 7.
Advantageously, the oscillating frames 9, 10 compensate for the block of the plastic film 4 for applying the zip closure strip 3 on the plastic film 4.
In particular, the first oscillating frame 9, mounted idle on bar 27, accumulates the plastic film 4 in braking stage by rotating downwards, and releases the plastic film 4 in acceleration stage by rotating upwards, as shown in Figure 4, in which the plastic film 4 is free to slide between rotor 7 and the sealing bar 8, moved by the blocking and actuating cylinder 25 in motion position.
The second oscillating frame 10 is instead actuated into rotation by the pneumatic piston 35, rotating upwards to recover the plastic film 4 with the zip closure strip 3 already applied, when the portion of plastic film 4 between the sealing bar 8 and rotor 7 is stopped for the application of the zip closure strip 3 (Figure 3). When the motion of the plastic film 4 between the sealing bar 8 and rotor 7 resumes, the second oscillating frame 10 rotates downwards to compensate for the plastic film 4 in excess with respect to what is required to keep constant and continuous the motion of the plastic film 4 with the zip closure strip 3 applied downstream of the zip group 2 (Figure 4).
Preferably, also the first oscillating frame 9 is actuated by a pneumatic piston, like the second oscillating frame 10. Advantageously, there is an increased control of the blocking and sliding of the plastic film 4.
Advantageously, the zip group 2 according to the present invention is associable with known packaging machines without zip groups, before the forming station of the plastic film tube, after the plastic film is unwound from its reel.
The actuators of the zip group 2 are preferably of pneumatic and/or electric type, i.e., simple and reactive.
Equivalent actuators are, however, possible. For example, in place of the pneumatic piston 35, it is possible to provide an electric motor actuating the second oscillating frame 10.
The presence of the pair of oscillating frames 9, 10 is essential, one upstream and one downstream of the area where the plastic film 4 is blocked for the application of the zip closure strip 3. The mounting of the oscillating frames 9, 10 on upright 15 can vary, the identification of the two oscillation axes 17, 20 lying orthogonal to the sliding direction of the plastic film 4 being essential.
A control unit synchronizes the movements of all devices of the zip group 3. For example, the sealing bar 8 must be ready and quick to operate when the plastic film 4 is stopped. Or the suction means 6 of rotor 7 must be ready and quick to release the zip closure strip 3 when the sealing bar 8 fixes the zip closure strip 3 to the plastic film 4.
As mentioned above, the number of rollers 12, 19, 32 may vary according to the production speed, type of plastic film 4 or other features that can be assessed by the designer.
Also, the shape of the frames 9, 10, 30 can vary, i.e., it must be simply adapted to support said rollers 12, 19, 32 parallel to one another.
The packaging machine 1, with the zip group 2, is efficient and has identical productivity to that it would have without the zip group 2.

Claims

Zip group (2), for long pasta packaging machine (1), suitable for applying a zip closure strip (3) on a plastic film (4) suitable for making bags to accommodate doses of long pasta,
wherein the zip group (2) provides a zip application device (40) comprising a reel (50) of a zip closure tape (3), a rotor (7) capable of feeding a defined length of zip closure strip (3) for application on the plastic film (4), a sealing bar (8) for applying the zip closure strip (3) on the plastic film (4), feeding and cutting means (5) of the zip closure tape (3) to define the zip closure strip (3) for the rotor (7), and suction means (6) of the zip closure strip (3) on the rotor (7),

wherein the rotor (7) is able to retain zip closure strips (3) by means of said suction means (6) in correspondence with suction seats (80), and to rotate according to a predefined angular step so as to sequentially arrange zip closure strips (3) in a position suitable for application on the plastic film (4) using the sealing bar (8),

wherein

the zip group (2) also includes a first oscillating frame (9) upstream of the rotor (7), a second oscillating frame (10) downstream of the rotor (7), a guide frame (30) above the second oscillating frame (10), and blocking and actuating means (23) of the plastic film (4) downstream of the rotor (7) and upstream of the second oscillating frame (10),

wherein the first oscillating frame (9) includes rollers (12) for guiding the motion of the plastic film (4) having an axis of rotation orthogonal to the direction of sliding of the plastic film (4), and is mounted on coupling means integral with uprights (15) of the zip group (2) so as to be able to rotate around a first axis of oscillation (17) parallel to the axis of rotation of the rollers (12),

wherein the second oscillating frame (10) includes rollers (19) for guiding the motion of the plastic film (4) parallel to the rollers (12) of the first oscillating frame (9), and is mounted on coupling means integral with uprights (15) of the zip group (2) so as to be able to rotate around a second oscillation axis (20) parallel to the first oscillation axis (17), the oscillation of the second oscillating frame (10) being controlled by actuating means (35),

wherein the guide frame (30) includes rollers (32) parallel to the rollers (19) of the second oscillating frame (10),

characterized in that

the blocking and actuating means (23) comprises at least one friction element (24) fixed because it is integral with a bar (26) parallel to the rollers (12, 19) and integral with the uprights (15), and a drive roller (25) parallel to the bar (26),

wherein the friction element (24) and the drive roller (25) face each other at a variable distance by means of actuating means (28) suitable for translating the drive roller (25) between a motion position of the plastic film (4) wherein the friction element (24) and the drive roller (25) are spaced so as to allow the plastic film (4) to move by means of the driving rotation of the drive roller (25) on the plastic film (4), and a blocking position of the plastic film (4) wherein the drive roller (25) is disactivated for the driving rotation and the plastic film (4) is squeezed between the friction element (24) and the drive roller (25).
Zip group (2) according to claim 1, characterized in that
the first oscillating frame (9) includes two parallel arms (11) between which the rollers (12) extend, rotatably fixed to said parallel arms (11), wherein said parallel arms (11) of the first oscillating frame (9), in correspondence of constrained ends (13), are associated with a bar (14) parallel to the rollers (12) and integral with the uprights (15),

the second oscillating frame (10) includes two parallel arms (18) between which the rollers (19) extend, rotatably fixed to said parallel arms (18), wherein said parallel arms (18) of the second oscillating frame (10), in correspondence of constrained ends (22), are associated with pins integral with the uprights (15), and

the guide frame (30) includes two arms (31) integral with the uprights (15) between which the rollers (32) rotatably fixed to said parallel arms (31) extend.
Zip group (2) according to claim 1 or 2, characterized in that the oscillation of the second oscillating frame (10) is actuated by a pneumatic piston (35) comprising a cylinder (36) rotatably fixed to the guide frame (30), and a stem (37) sliding in the cylinder (36) and having one end, external to the cylinder (36), rotatably fixed to a free end (38) of the parallel arms (18) of the second oscillating frame (10).
Zip group (2) according to any of the previous claims, characterized in that the oscillation of the first oscillating frame (9) is controlled by actuating means, preferably a pneumatic piston.
Packaging machine (1) for the production of plastic film bags filled with doses of long pasta, includes a dosing station for the long pasta, a station for forming a plastic film tube, a station for the periodic insertion of doses of long pasta in the plastic film tube, and a sealing and cutting station of the plastic film tube filled with doses of long pasta to obtain a plurality of plastic film bags with defined doses of long pasta for sale, characterized by comprising a zip group (2) according to any of the previous claims.