Lidding machine for heat-sealing film onto containers
The lidding machine addresses the issue of thin or brittle films by using guide pairs to generate tensile forces perpendicular to the film's movement, maintaining shape and preventing tearing, thus ensuring effective sealing.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- MECAPLASTIC
- Filing Date
- 2024-11-13
- Publication Date
- 2026-05-15
AI Technical Summary
Existing sealing machines struggle with the use of thin or brittle films that wrinkle or stretch during the sealing process, leading to poor sealing and potential breakage due to increased tension, which is not suitable for reducing environmental impact or meeting mechanical constraints.
A lidding machine with a film sealing and cutting station equipped with movable upper and lower tooling, a container conveying device, and a drive device for film strip movement, featuring a guide path with pairs of guides that generate tensile forces perpendicular to the film's direction of movement to maintain shape and prevent tearing.
The solution effectively maintains the shape of the film during sealing, preventing creasing or tearing, even with reduced thickness, ensuring proper sealing and film advancement without breakage.
Smart Images
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Abstract
Description
Title of the invention: Lidding machine for thermally sealing film onto containers
[0001] The present invention relates to the field of containers. In particular, the invention relates to a sealing machine for heat-sealing film onto containers. Said machine comprises: at least one film sealing and cutting station with upper and lower tooling mounted movably in the direction of bringing them closer together and moving them apart; a container conveying device, said conveying device allowing the containers to pass through said at least one film sealing and cutting station; a discontinuous drive device for the conveying device to allow, when the conveying device is stopped, sealing by relative displacement of the lower and upper tooling; at least one drive device for moving a sealing film in strip, said drive device comprising a first storage zone for storing the portion of the film in strip to be cut in the wound state, a second storage zone for storing the offcut of the cut film in the wound state called skeleton, a guide path for the film in strip between the first and second zones passing through the film sealing and cutting station and at least one drive element for driving the film in the wound state along the guide path and its passage from the first zone to the second zone.
[0002] Lidding consists of sealing the opening of a container with a film generally made of plastic and / or aluminum and / or cellulose during the packaging of a product, particularly food, guaranteeing its quality before consumption.
[0003] To perform this sealing, it is known to use machines comprising a container conveying device that allows the containers to pass through a film sealing and cutting station. This film is generally in the form of a roll unwound to pass through the film cutting and sealing station.
[0004] During the capping process, the die-cutting sealing station applies the film to the containers, seals it, and cuts it. After capping, a portion of the film, called the skeleton, is perforated due to the cuts.
[0005] In order to reduce the environmental impact of the containers and / or meet certain constraints, it is possible to reduce the film thickness or use a film with more brittle or flexible characteristics. However, after cutting, the film backbone wrinkles or stretches, which prevents proper film advancement and results in poor sealing. One solution could have been to increase the tension on the film along its direction of advancement. However, since the backbone is fragile, increasing the tension on the backbone in this direction could cause it to break.
[0006] There is a need for a sealing machine that allows the use of a film in strip form of reduced thickness and / or with mechanical characteristics likely to generate breakage or deformation of the film.
[0007] To this end, the invention relates to a capping machine for thermally welding film onto containers, said machine comprising: at least one film sealing and cutting station with an upper tooling and a lower tooling mounted movably in the direction of approaching and moving away from each other; a container conveying device, said conveying device allowing the containers to pass through said at least one film sealing and cutting station; a discontinuous drive device for the conveying device to allow, when the conveying device is stopped, sealing by relative displacement of the lower and upper tooling; at least one drive device for moving a sealing film strip, said drive device comprising a first storage zone for storing the portion of the film strip to be cut in the wound state, a second storage zone for storing the offcut of the cut film strip, known as the skeleton, in the wound state, a film strip guide path between the first and second zones passing through the film sealing and cutting station, and at least one drive element for driving the film strip along the guide path and its passage from the first zone to the second zone, characterized in that the guide path comprises at least one pair of film strip guides, said guides being arranged on either side of the guide path, each guide being configured to generate a tensile force on the film strip in the direction of widening of the film strip.
[0008] Said at least one pair of guides which generates tensile forces in the direction of an expansion of the film in strip makes it possible to maintain the shape of the fall of the cut film in strip which prevents it from creasing or relaxing, while preventing it from tearing, even for a film of reduced thickness.
[0009] According to one embodiment of the invention, the traction forces generated by the guides of said at least one pair of guides are perpendicular to the direction of movement of the film in strip.
[0010] According to one embodiment of the invention, the norms of the traction forces generated by the guides of said at least one pair of guides are substantially equal to each other.
[0011] According to one embodiment of the invention, the guides are non-motorized and are configured to guide by rolling and / or sliding.
[0012] According to one embodiment of the invention, each guide of said at least one pair of guides comprises two guiding members delimiting a pinching zone of the film in strip.
[0013] Each guide element of a guide of said at least one pair of guides can be a rotary guide element, for example a roller or a track, or a sliding guide element.
[0014] The rotary guide member includes a rotating tread configured to be in contact with the film in strip.
[0015] The tread can be made of elastomer.
[0016] According to one embodiment of the invention, the guide members of a guide are rotary guide members with parallel axes of rotation whose axis of rotation forms an angle between 0 and 10° with an axis perpendicular to the direction of movement of the film in strip.
[0017] Alternatively, the guide members of a guide are rotary guide members with non-parallel axes of rotation, the axis of rotation of at least one of the guide members forms an angle between 0 and 10° with an axis perpendicular to the direction of movement of the film in strip.
[0018] According to one embodiment of the invention, the axes of rotation of the guide members of the guides of a pair of guides form, from the top of the guide path, a V open in the direction of the first zone.
[0019] According to one embodiment of the invention, each guide includes a means for adjusting the generated traction force.
[0020] According to one embodiment of the invention, the adjustment means is configured to modify the direction of the axis of rotation of the rotating members relative to the direction of movement of the film in strip.
[0021] The adjustment means can be configured to adjust the pinching force of the film in strip.
[0022] According to one embodiment of the invention, the guides of said at least one pair of guides are arranged on opposite sides of the guide path, that is to say, along a direction perpendicular to the direction of movement of the film strip.
[0023] According to one embodiment of the invention, the guide path comprises several pairs of film strip guides.
[0024] According to one embodiment of the invention, the guide path comprises a first pair of film strip guides at an inlet of said at least one film sealing and cutting station taken along the direction of movement of the film strip from the first zone to the second zone, and in that the guide path comprises a second pair of film strip guides at an outlet of said at least one film sealing and cutting station taken along the direction of movement of the film strip from the first zone to the second zone.
[0025] According to one embodiment of the invention, the guide path comprises at least one third pair of film strip guides at an intermediate position between the entry of said at least one film sealing and cutting station and the exit of said at least one film sealing and cutting station.
[0026] According to one embodiment of the invention, the guides are mounted as a unit with the upper tooling.
[0027] The film preferably has a thickness between 1 Opm and 300 pm.
[0028] The film strip can be made of polymer material or aluminum.
[0029] The machine can include between 2 and 20 pairs of guides. Brief description of the drawings
[0030] The invention will be better understood upon reading the following description of exemplary embodiments, with reference to the accompanying drawings in which:
[0031] [Fig-1] illustrates, in perspective, an example of a capping machine according to the invention,
[0032] [Fig.2] illustrates, in cross-section, side view, the capping machine of [Fig.1],
[0033] [Fig.3] illustrates, in perspective, a partial view of the capping machine of [Fig.1], in which the film strip, the conveying device, and the lower tool are shown.
[0034] [Fig.4] is an enlargement of [Fig.3] at the level of the lower tool,
[0035] [Fig.5] is an enlargement of [Fig.4] at the level of a guide,
[0036] [Fig.6] represents, in top view, a partial view of the capping machine of [Fig.1], in which a portion of the film strip and the guide pairs are shown,
[0037] [Fig.7] illustrates, in perspective, a partial view of the capping machine of [Fig.1], in which the film strip and the upper tool are shown,
[0038] [Fig.8] illustrates, in cross-section, side view, partially the capping machine of [Fig.1] in a first position of the film sealing and cutting station,
[0039] [Fig.9] is a view similar to [Fig.8] in which the film sealing and cutting station is in a second position, and
[0040] [Fig. 10] is a view similar to [Fig.8] in which the film sealing and cutting station is in a third position.
[0041] In the following description, identical elements or elements with identical functions bear the same reference numeral. For the sake of brevity, they are not described opposite each figure; only the differences between the embodiments are described.
[0042] In the figures, the actual proportions have not always been respected, for the sake of clarity.
[0043] Figures 1 to 10 illustrate an example of a capping machine 100 according to the invention.
[0044] The capping machine 100 is designed for sealing, for example by heat welding, film onto containers 101.
[0045] The machine 100 comprises a film sealing and cutting station 102 with an upper tool 1 and a lower tool 2 mounted movably in the direction of moving closer to and further away from each other. In particular, only one of the upper tool 1 and the lower tool 2 is movable, namely the upper tool 1.
[0046] The machine 100 also includes a container conveying device 3 for the containers 101 which allows the containers 101 to pass through the sealing and film cutting station 102. A drive device 4 allows the discontinuous movement of the conveying device 3 in a direction of movement to allow, in the stopped state of the conveying device 3, sealing by relative movement of the lower tooling 2 and upper tooling 1.
[0047] The machine 100 also includes a motor device 5 for driving a lidding film 103 in strip form, in particular made of polymer material, for example thermoplastic. This motor device 5 includes a first storage area 6 for storing, in the wound state, the portion of the film 103 in strip form to be cut, and a second storage area 7 for storing, in the wound state, the offcut 104 of the cut film 103 in strip form, called the skeleton, as will be detailed later.
[0048] The 103 film in strip form has, in this example, a thickness of 20 µm.
[0049] A guide path 8 of the film 103 in strip is disposed between the first 6 and second 7 zones. This guide path 8 crosses the film sealing and cutting station 102.
[0050] At least one drive element 9 is provided to enable the film 103 to move along the guide path 8 and from the first zone 6 to the second zone 7. The direction of movement Dp of the film 103 corresponds to the direction of movement of the container conveyor 3 101 at the sealing and cutting station. The direction of movement of the film in the strip, within the sealing and cutting station, is parallel to the longitudinal axis of the portion of the film guide path 8 located at the sealing and cutting station.
[0051] The guide path 8 comprises, in this example, three pairs of guides 10 of the film 103 in strip, arranged on either side of the guide path 8.
[0052] A first pair of guides 10 is located at an entrance 105 of the film sealing and cutting station 102 taken along the direction of movement Dp of the film 103 in strip from the first zone 6 to the second zone 7.
[0053] A second pair of guides 10 is located at an exit 106 of the film sealing and cutting station 102 taken along the direction of movement Dp of the film 103 in strip from the first zone 6 to the second zone 7.
[0054] A third pair of guides 10 is located at an intermediate position, in this example, median, between the inlet 105 and the outlet 106 of the film sealing and cutting station 102.
[0055] The guides 10 are mounted as a fixed part of the upper tooling 1. This ensures that the guides 10 remain in contact with the film 103 during the movements of the upper tooling 1.
[0056] The guides 10 of the same pair of guides 10 are aligned on the same axis perpendicular to the direction of movement Dp. These guides 10 are arranged in the same plane parallel to the film 103 in strip at the level of said pair of guides.
[0057] As illustrated in [Fig.6], each guide 10 is configured to generate a force Fg when the film 103 in strip moves in the direction of displacement Dp.
[0058] This force Fg is decomposed into a friction force Fr, opposite to the direction of displacement Dp, and a traction force F on the film 103 in strip perpendicular to the direction of displacement Dp of the film 103 in strip, that is to say in the direction of an expansion of the film 103 in strip.
[0059] The tensile forces F generated by the guides 10 of the same pair of guides are in opposite directions and have magnitudes, i.e., essentially equal absolute values. Thus, the film strip is not, or only slightly, deflected from its trajectory along the guide path 8 during its movement.
[0060] As illustrated in Figures 5 and 6, in this example, each guide 10 comprises two rotating guide members 11 delimiting a pinching zone of the film 103 in strip.
[0061] The rotating guide members 11 of a guide 10 are in particular rolling rollers with a substantially circular tread. The tread may be made of an elastomeric material.
[0062] The rotating guide members 11 of a guide 10 have parallel axes of rotation X. Furthermore, the axis of rotation X forms an angle B with an axis perpendicular to the direction of movement Dp of the film 103 in strip, an angle B between 0 and 10°, in particular between 5° and 10°.
[0063] The rotation axes X of the guide members 11 of the guides 10 of a pair of guides 10 thus form from the top of the guide path 8 an open V in the direction of the first zone 6.
[0064] Each guide 10 includes a means for adjusting the generated traction force F.
[0065] In this example, the adjustment means 12 includes a screw 130 for adjusting the pinching force of the film 103 in strip between the rotating guide members 11.
[0066] In addition, the adjustment means includes screws 131 allowing adjustment of the angle B between the axis of rotation X and an axis perpendicular to the direction of movement Dp of the film 103 in strip.
[0067] In the following, an example of the use of machine 100 is presented.
[0068] As illustrated in Figures 8 to 10, during the capping operation, the conveying device 3 will move containers 101, in this example four containers 101, to position them between the upper tooling 1 and the lower tooling 2 ([Fig.8]).
[0069] The film 103 in strip is also unrolled from the first storage area 6 to the second storage area 7. The part of the film 103 in strip below the containers 101 is solid, i.e. not perforated.
[0070] Next, as illustrated in [Fig.9], the upper tooling 1 is moved downwards towards the lower tooling 1. Then, support and sealing plates 120 carried by the upper tooling 1 press the film 103 in strip onto the containers 101 to perform the sealing, as illustrated in [Fig.10].
[0071] The upper tooling 1 is then moved away from the lower tooling 2.
[0072] The drop 104 of the film 103 in strip must then be moved to the second storage area 7. During this movement, which is done along the direction of movement Dp, each guide 10 will generate a tensile force F on the film 103 in strip in a direction of widening of the film 103 in strip.
[0073] The invention is not limited to the example just described.
[0074] In particular, the machine 100 can include a number of guide pairs 10 different, especially between 2 and 10 pairs of guides 10.
[0075] The machine 100 can be configured to seal a different number of containers simultaneously, in particular between 2 and 10.
Claims
Demands
1. A sealing machine (100) for heat-sealing film onto containers (101), said machine comprising: at least one film sealing and cutting station (102) with an upper tooling (1) and a lower tooling (2) mounted movable in the direction of approaching and moving away from each other; a conveying device (3) for the containers (101), said conveying device (3) allowing the containers (101) to pass through said at least one film sealing and cutting station (102); a drive device (4) for discontinuously driving the conveying device (3) to allow, in the stopped state of the conveying device (3), sealing by relative movement of the lower tooling (2) and upper tooling (1); at least one drive device (5) for moving a sealing film (103) in strip form,said drive device (5) comprising a first storage zone (6) for storing the portion of the film (103) in strip to be cut in the wound state, a second storage zone (7) for storing the offcut (104) of the film (103) in strip, called skeleton, in the wound state, a guide path (8) for the film (103) in strip between the first (6) and second (7) zones passing through the film sealing and cutting station (102) and at least one drive element (9) for driving the film (103) in strip along the guide path (8) and its passage from the first zone (6) to the second zone (7), characterized in that the guide path (8) comprises at least one pair of guides (10) for the film (103) in strip, said guides (10) being arranged on either side of the guide path (8),each guide (10) being configured to generate a tensile force (F) on the film (103) in the direction of widening of the film (103) in the strip.
2. Machine (100) according to the preceding claim, characterized in that the traction forces (F) generated by the guides (10) of said at least one pair of guides (10) are perpendicular to the direction of movement of the film (103) in strip.
3. Machine (100) according to claim 1 or 2, characterized in that the standards of the traction forces (F) generated by the guides (10) of said at least one pair of guides (10) are substantially equal to each other.
4. Machine (100) according to any one of the preceding claims, characterized in that the guides (10) are non-motorized and are configured to guide by rolling and / or sliding.
5. Machine (100) according to any one of the preceding claims, characterized in that each guide (10) of said at least one pair of guides comprises two guiding members (11) delimiting a pinching zone of the film (103) in strip.
6. Machine (100) according to the preceding claim, characterized in that the guide members (11) of a guide (10) are rotary guide members with parallel axes of rotation (X) whose axis of rotation (X) forms an angle between 0 and 10° with an axis perpendicular to the direction of movement (Dp) of the film (103) in strip
7. IV • Machine (100) according to the preceding claim, characterized in that the axes of rotation (X) of the guide members (11) of the guides (10) of a pair of guides form, from the top of the guide path (8), a V open in the direction of the first zone (6).
8. Machine (100) according to any one of claims 1 to 7, characterized in that each guide (10) includes a means for adjusting (12) the generated traction force (F).
9. Machine (100) according to the preceding claim taken in combination with claim 6, characterized in that the adjustment means (12) is configured to modify the direction of the axis of rotation (X) of the rotating members (11) relative to the direction of movement (Dp) of the film (103) in strip.
10. Machine (100) according to any one of the preceding claims, characterized in that the guides (10) of said at least one pair of guides (10) are arranged on the banks of the guide path (8) opposite each other, that is to say in a direction perpendicular to the direction of movement (Dp) of the film (103) in strip.
11. Machine (100) according to any one of the preceding claims, characterized in that the guide path (8) comprises several pairs of guides (10) for the film (103) in strip.
12. Machine (100) according to the preceding claim, characterized in that the guide path (8) comprises a first pair of guides (10) of the film in strip at an input (105) of said at least one film sealing and cutting station (102) taken along the direction of movement of the film (103) in strip from the first zone (6) to the second zone (7), and in that the guide path (8) includes a second pair of guides (10) of the film (103) in strip at an output (106) of said at least one film sealing and cutting station (102) taken along the direction of movement (Dp) of the film (103) in strip from the first zone (6) to the second zone (7).
13. Machine (100) according to the preceding claim, characterized in that the guide path (8) comprises at least a third pair of film (10) guides (10) in strip at an intermediate position between the inlet (105) of said at least one film sealing and cutting station (102) and the outlet (106) of said at least one film sealing and cutting station (102).
14. Machine (100) according to any one of claims 1 to 13, characterized in that the guides (10) are mounted integrally with the upper tooling (1).