Packaging line for a compressible material in plastic film, comprising a bundling machine

Abstract

The invention relates to a line for packaging a compressible material (M) in plastic film, comprising: - a compression module (1) for the material; - a shrink-wrapper (2), in the extension of the compression module in a direction of travel of the material so as to shrink-wrapper the material in a compressed state, - an output module (4), in the immediate extension of the shrink-wrapper (2) in a direction of travel of the material, maintaining the material in a compressed state, - an interlayer module (3) arranged between the compression module (1) and the shrink-wrapper (2) so as to be able to provide a functional gap with the output module (4), capable of maintaining the material in a compressed state, characterized in that it comprises means for setting in motion (5) the interlayer module (3) relative to the compression module (1) and / or relative to the output module (4),controlled so that the interposed module (3) adjoins the compression module (1) and provides the functional gap with the output module (4), or, alternatively, so that the interposed module (3) adjoins the output module (4) and provides a gap with the compression module (1).,

Description

[0001] The field of the invention is that of the design and manufacture of packaging machines under plastic film, and in particular under polyethylene film.

[0002] More specifically, the invention relates to the design of shrink-wrapping machines and associated equipment.

[0003] It is worth remembering that the function of a shrink wrapper is to wrap products in plastic film, whether heat-shrinkable or not. The shrink wrapper is generally the first element in a plastic film packaging line, preferably using polyethylene film.

[0004] The operating principle of a shrink wrapper is as follows: an upper plastic film is sealed to a lower film to form a nearly vertical film curtain. The product to be wrapped is conveyed by a conveyor towards the pre-formed curtain. The conveying of the product causes it to be pushed against the curtain, which then unwinds the upper and lower films from their respective rolls. Photoelectric cells (or another method) detect the rear end of the product to be wrapped, at which point the conveyor stops. At this stage, a sealing device automatically closes the upper and lower films behind the product. Generally, a double seal and a cut are performed, thus completing the wrapping of the product.

[0005] At the same time, the film curtain is being rebuilt for the next product.

[0006] Of course, each shrink wrapper is designed and manufactured according to the dimensions and characteristics of the products to be packaged.

[0007] According to a classic design of shrink wrappers, the upper plastic film is unwound from a horizontal reel positioned above the conveyor and transversely to it, while the lower plastic film is unwound from a horizontal reel positioned below the conveyor, and also transversely to it.

[0008] Shrink-wrapping, particularly using shrink wrappers, has been around for a number of years now. Initially limited to certain sectors, its use has expanded and continues to grow across all industries.

[0009] In particular, plastic film packaging is now commonly used for compressible insulating materials, such as glass wool or rock wool, or more generally any type of bio-based compressible material such as wood, hemp, cotton, recycled cardboard, PVC fibers...

[0010] Naturally, with such compressible materials, the material is first compressed before packaging, and then the compression is maintained during the packaging process. The aim is obviously to reduce the volume of the packaged compressible products during transport and storage.

[0011] To achieve compression of the material before packaging, several techniques are known from the prior art.

[0012] According to a known technique, the compressible material is pushed into a funnel-shaped cavity, which promotes forced compression of the material. Upon exiting the funnel, the material is fed into a shrink wrapper which wraps the material in plastic film while preserving its compressed state.

[0013] According to another technique described by the figures 1 à 6 A packaging line for a compressible material under plastic film includes: a compression module 1 of the material M, comprising a lower compression plate 10 and an upper compression plate 11, movable in height relative to each other from an admission position of the material M in an uncompressed state as illustrated by the figure 1 , to a close position designed to bring the material into a compressed state as illustrated by the figure 2 ; a shrink wrapper 2, in the extension of the compression module 1 in a direction of material flow D, so as to shrink the material in a compressed state, an output module 4, comprising a lower output plate 40 and an upper output plate 41 separated from each other in height so as to maintain the material M in a compressed state.

[0014] In a classic manner, the shrink wrapper also includes: a lower reel 20; an upper reel 21; a lower sealing bar 22 (also referred to as "counter sealing bar") and an upper sealing bar 23, movable relative to each other to, firstly, join the plastic film of the upper reel and the plastic film of the lower reel in order to form a film curtain and, secondly, to weld the lower and upper parts of the film curtain behind the product.

[0015] Typically, a double weld is performed and a cut is made between the two welds, thus completing the wrapping of the product.

[0016] According to this technique, the line further includes an interlayer module 3, arranged between the compression module 1 and the shrink wrapper 2, this module comprising a lower interlayer plate 30 and an upper interlayer plate 31, separated from each other in height so as to maintain the material in a compressed state.

[0017] This intercalary module is arranged between the compression module and the output module so as to provide a functional gap E, through which the film curtain is intended to extend and through which the upper sealing bar 21 can be moved towards the lower sealing part 20 to make the seals necessary for the proper unfolding of the bundling.

[0018] Furthermore, a valve C is provided to close the functional gap at the level of the upper output tray 41 and the upper intermediate tray 31 during the passage of the material M between the intermediate module and the output module. This valve C is movable, specifically pivotable, between a position in which it closes the functional gap, and a position in which it allows the passage of the welding means through the functional gap once the material M has passed between the intermediate module and the shrink wrapper.

[0019] Thus, according to prior art, the packaging of a compressible material under plastic film is carried out according to the following steps: the material M is admitted into the compression module 1, while the lower plate 10 and the lower plate 11 are separated from each other by a height greater than or equal to that of the material M ( figure 1 ) ; the upper plate 11 of the compression module 1 is lowered towards the lower plate 10 so as to compress the material M ( figure 2 ); the material M is transferred from the compression modulus 1 to the intercalated modulus 3.

[0020] It is noted that during these first steps, a film curtain is made beforehand so as to join the film of the lower reel 20 to that of the upper reel 21. In addition, the flap C is kept in the closed position, ensuring closure of the functional space E and ensuring continuity of support between the upper intercalated plate 31 and the upper output plate 41.

[0021] The lower welding bar 20 extends in the plane of the lower intermediate plate 30 and the lower output plate 40.

[0022] Thus, the material M is transferred from the interlayer module 3 to the output module 4, by being pushed against the film curtain extending between the lower reel 20 and the upper reel 21 ( figure 4 ).

[0023] While the conveying of material M continues between the lower output tray and the upper output tray, by unwinding the plastic film from the lower reel 20 and the upper reel 21, the valve C is brought into the open position of the functional space E ( figure 5 ).

[0024] The lower welding bar 20 and the upper welding bar 21 can then be moved within the functional gap E so as to carry out the double welding of the plastic film and the cutting between the two welds made ( figure 6 ).

[0025] Such a packaging line ensures the expected result, namely compressing the compressible material and wrapping it in a plastic film while it remains in a compressed state.

[0026] On the other hand, the proper functioning of this prior art conditioning line necessarily implies the implementation of the valve C, otherwise the material M would tend to expand in the functional space, when passing from the intercalated module 3 to the output module 4.

[0027] However, implementing such a valve is not without its difficulties in terms of assembly and adjustment. These difficulties are further compounded by the complexity of controlling the valve, in order to synchronize its opening and closing with the movement of the welding equipment within the functional gap between the interleaving module and the shrink wrapper.

[0028] Furthermore, the gate necessarily has a certain length in the direction of material flow. However, this gate is not a conveyor. Consequently, materials with a shorter length in the direction of flow than the gate are incompatible with such a prior art packaging line, as they would become stuck at the gate due to the lack of conveying at that point.

[0029] The invention aims in particular to overcome this drawback of the prior art.

[0030] More specifically, the invention aims to provide a packaging line for a compressible material under plastic film of the type comprising a compression module, a shrink wrapper and an interlayer module disposed between the shrink wrapper and the compression method, which allows the functional gap between the interlayer module and the shrink wrapper to be filled in a simpler, more reliable and more durable way than with the prior art solution.

[0031] The invention also aims to provide such a packaging line which makes it possible to increase packaging rates.

[0032] These objectives, as well as others that will emerge subsequently, are achieved through the invention, which relates to a packaging line for a compressible material under plastic film, comprising: a material compression module, comprising a lower compression plate and an upper compression plate movable in height relative to each other from a material admission position in an uncompressed state to a close position intended to bring the material into a compressed state;a shrink wrapper, extending from the compression module in the direction of material flow so as to shrink the material in a compressed state; an output module, immediately extending from the shrink wrapper in the direction of material flow, comprising a lower output plate and an upper output plate spaced apart vertically so as to maintain the material in a compressed state; an interlayer module disposed between the compression module and the shrink wrapper so as to allow a functional gap with the output module; the interlayer module comprising a lower interlayer plate and an upper interlayer plate spaced apart vertically so as to maintain the material in a compressed state.

[0033] According to the invention, the packaging line includes means for moving the interlayer module relative to the compression module and / or relative to the output module, the means for moving being controlled so that the interlayer module is adjacent to the compression module and maintains the functional gap with the output module, the functional gap being suitable for allowing the passage of an upper plastic film, a lower plastic film and means for welding the upper plastic film with the lower plastic film to create a film curtain or, alternatively, so that the interlayer module is adjacent to the output module and maintains a space with the compression module.

[0034] Thus, thanks to the invention, we do not need to implement a valve to close the functional gap between the shrink wrapper and the interlayer module to keep the material compressed while it passes through this gap.

[0035] Indeed, the means of moving the interleaving module advantageously replace this valve, by alternately ensuring the presence of the functional gap when the interleaving module is moved away from the shrink wrapper or, conversely, by ensuring continuity of the respective plates of the interleaving module and the output module, which keeps the material compressed during its transition from the interleaving module to the shrink wrapper.

[0036] Note that the term "in the immediate extension," when referring to the positioning of the output module relative to the shrink wrapper, means that the input of the output module is directly adjacent to the shrink wrapper film, downstream of it in the direction of material flow. Upstream of the film, the interleaving module is likely to occupy a position with no gap between it and the shrink wrapper, and therefore with little or no gap between it and the shrink wrapper film. Thus, during the transfer of material from the interleaving module to the output module, the interleaving module and the output module are in close proximity to each other, on either side of the shrink wrapper film.

[0037] According to an advantageous solution, the compression module is fixed and the intercalated module is mobile relative to the compression module.

[0038] More specifically, the intercalated module is mobile in translation relative to the compression module, according to the direction of material flow.

[0039] Regardless of this feature or in combination with it, the shrink wrapper can advantageously be fixed and the interleaving module mobile relative to the shrink wrapper.

[0040] Again, the interlayer module is mobile in translation in the direction of material flow.

[0041] Of course, in the case where only the intermediate module is mobile, we obtain an embodiment that is both advantageous and simplified from a kinematic point of view.

[0042] Advantageously, the lower intermediate plate and the upper intermediate plate are aligned in height respectively with the lower compression plate and the upper compression plate when they occupy the close position.

[0043] In this case, the lower intermediate tray and the upper intermediate tray are advantageously aligned in height with the lower output tray and the upper output tray respectively.

[0044] It is understood that, in this way, the compressible material is conveyed while remaining in the same plane defined by the set of lower plates of the compression module, the intercalated module and the output module, with the respective upper plates also aligned in height to maintain the compressed state of the material.

[0045] According to an advantageous embodiment, the packaging line also has one or both of the following characteristics: the lower compression plate carries a first conveyor of the material in a direction of material flow; the lower intermediate plate carries a second conveyor of the material in a direction of material flow; the lower output plate carries a third conveyor of the material in a direction of material flow.

[0046] Thus, an advantageous characteristic is retained with regard to integrating the conveying means into the lower platform of each module.

[0047] According to yet another particular feature, the line includes a sensor for detecting the functional gap between the intercalated module and the output module and also includes a control unit capable of receiving a signal of the presence of the functional gap from the sensor for detecting the functional gap, the control unit being parameterized to cause a displacement and a weld by the welding means after receiving the signal of the presence of the functional gap.

[0048] In this way, it is easy to synchronize the movement of the welding means through the functional gap with the movement of the intermediate module towards the compression module, that is to say in a position in which it precisely preserves the functional gap with the output module.

[0049] Other features and advantages of the invention will become more apparent upon reading the following description of a preferred embodiment of the invention, given by way of illustrative and non-limiting example, and the accompanying drawings, among which: there figure 1 illustrates an initial conditioning phase of a compressible material with a prior art line; the figure 2 illustrates a second phase of conditioning a compressible material with a prior art line; the figure 3 illustrates a third phase of conditioning a compressible material with a line of prior art; the figure 4 illustrates a fourth phase of conditioning a compressible material with a line of prior art; the figure 5 illustrates a fifth conditioning phase of a compressible material with a prior art line; the figure 6 illustrates a sixth conditioning phase of a compressible material with a prior art line; the figure 7 illustrates a first phase of conditioning a compressible material with a conditioning line according to the invention; the figure 8 illustrates a second phase of conditioning a compressible material with a conditioning line according to the invention; the figure 9 illustrates a third phase of conditioning a compressible material with a conditioning line according to the invention; the figure 10 illustrates a fourth phase of conditioning a compressible material with a conditioning line according to the invention; the figure 11 illustrates a fifth conditioning phase of a compressible material with a conditioning line according to the invention; the figure 12 illustrates a sixth conditioning phase of a compressible material with a conditioning line according to the invention.

[0050] With reference to figures 7 à 12 , a packaging line for a compressible material under plastic film, according to the invention, is described below.

[0051] As schematically illustrated, such a conditioning line according to the invention comprises, in a manner known in itself, a compression module 1 of a compressible material M, comprising a lower compression plate 10 and an upper compression plate 11, the two plates being movable in height relative to each other to achieve compression of the material M. More specifically, the lower plate 10 is fixed in height and the upper compression plate 11 is movable in height from an admission position of the material M in an uncompressed state (the distance between the lower compression plate and the upper compression plate being then greater than or equal to the uncompressed height of the material M) to a position close to the lower compression plate, a position in which the material M is brought into a compressed state.

[0052] The packaging line also includes a shrink wrapper 2, positioned downstream of the compression module 1 along the direction D of material flow M in the packaging line. This shrink wrapper is typically composed of the following elements: an upper reel 21 from which an upper film is unwound; a lower reel 20 from which a lower film is unwound; a lower welding bar 22 and an upper welding bar 24, intended to be moved towards each other until they meet to effect a weld and in particular a double weld of the upper film with the lower film so as to create a film curtain.

[0053] The shrink wrapper (represented by dashed lines in the figures) essentially comprises a frame that supports the various elements listed above. According to this embodiment, the upper and lower reels are located above and below the interleaving module, respectively. However, it is also possible for the reels to be situated alongside the interleaving module, with angled return rollers to the shrink wrapper, as described, for example, in the text of the patent document published under number FR3108594.

[0054] Downstream of the shrink wrapper, in the direction of material flow, is an output module 4, comprising a lower output tray 40 and an upper output tray 41. The material M is conveyed between the two trays by pushing the film curtain (and thus unwinding the lower film from the lower reel and the upper film from the upper reel). Furthermore, in a particular embodiment, this output module incorporates lateral heating elements designed to shrink the plastic film (provided, of course, that it is heat-shrinkable).

[0055] In the context of the invention, the lower outlet plate 40 and the upper outlet plate 41 are spaced vertically apart from each other so as to maintain the material in a compressed state and, more specifically, in the compressed state as obtained by the compression modulus 1.

[0056] A packaging line according to the invention further comprises an interlayer module 3 disposed between the compression module 1 and the shrink wrapper 2, this module comprising a lower interlayer plate 30 and an upper interlayer plate 31 separated from each other in height so as to maintain the material in the compressed state obtained by the compression module 1. The disposition and dimensions of the interlayer module between the compression module 1 and the output module 4 are such that a functional gap E can be provided between the interlayer module 3 and the output module 4, as will be explained later.

[0057] According to the principle of the invention, the conditioning line further includes means for moving 5 the intercalated module 3, these means for moving the position of the intercalated module between the compression module 1 and the output module 4. In other words, the intercalated module can be moved relative to the compression module 1 and / or relative to the output module 4, in order to maintain, or not maintain, the functional gap E between the intercalated module 3 and the output module.

[0058] According to the present embodiment, the movement means 5 are controlled so that the intermediate module is moved between two positions, namely: a first position in which the intercalated module is adjacent to the compression module 1 and maintains the functional gap E with the output module; a second position in which the intercalated module is adjacent to the output module and maintains a space with the compression module 1.

[0059] The functional gap E is suitable for allowing the passage of the upper plastic film and the lower plastic film, as well as the passage of means for welding the upper plastic film with the lower plastic film in order to create a film curtain extending vertically, or almost, into the input of the output module.

[0060] As previously stated, the welding means comprise a lower welding bar 22 (also referred to as the "counter welding bar") and an upper welding bar 23 designed to cooperate together. In their respective inactive positions, the lower welding bar 22 is located above the level of the lower intermediate tray and the lower shrinkage tray, while the upper welding bar 23 is located above the upper intermediate tray and the upper shrinkage tray.

[0061] Means of movement known to those skilled in the art are employed to enable the lower welding bar 22 and the upper welding bar 23 to move between their inactive position and their welding position. According to the present embodiment, both the lower and upper welding bars are vertically movable towards each other, thereby reducing the time required for the welding operation (as opposed to the prior art technique where only one of the two bars is movable, generally the upper bar, and the other is fixed).

[0062] According to a preferred embodiment, the compression module is fixed while the intercalated module is mobile relative to the compression module, this of course in the direction of material flow.

[0063] Furthermore, the shrink wrapper and the output module are fixed and the interleaving module is mobile relative to the shrink wrapper and the output module, this of course also in the direction of material flow.

[0064] In other words, the movement means 5 are capable of causing a back-and-forth movement of the intercalated module 3 between the compression module 1 and the output module 4, so as, alternatively, to be adjacent to the compression module 1 and to be away from the output module 4 or to be adjacent to the output module 4 and to be away from the compression module 1.

[0065] Furthermore, preferably, the lower intermediate plate 30 and the upper intermediate plate 31 are aligned in height with, respectively, the lower compression plate 10 and the upper compression plate 11, when the latter occupy the close position tending to compress the material M.

[0066] Simultaneously, the lower output tray 40 and the upper output tray 41 are aligned in height respectively with the lower intermediate tray 30 and the upper intermediate tray 31.

[0067] The movement of material M along the conditioning line, in the direction of material flow D, is ensured by: the first conveyor 100 carried by the lower compression plate 10; a second conveyor 300 carried by the lower intermediate plate 30; a third conveyor 400 carried by the lower exit plate 40.

[0068] Furthermore, the line includes a sensor 6 for detecting the functional gap between the intercalated module 3 and the output module 4. The conditioning line also includes a control unit 7 capable of receiving a signal of the presence of the functional gap from the detection sensor 6, the control unit being parameterized to cause a movement and a weld by the welding means after receiving the signal of the presence of the functional gap.

[0069] The operation of a packaging line according to the invention is described below.

[0070] Material M is admitted into the compression module while the upper compression plate 11 is separated from the upper compression plate 10 by a height greater than that of material M ( figure 7 ). As an example, in this initial configuration of the conditioning line, the intercalated module is adjacent to the compression module 1 and provides a functional gap E with the output module 4.

[0071] The upper compression plate 11 is then brought closer to the lower compression plate 10 so as to compress, preferably as much as possible, the material M ( figure 8 ).

[0072] The material M is transferred in the intercalated module 3, between the lower intercalated tray 30 and the upper intercalated tray 31 ( figure 9 ).

[0073] The means of movement 5 move the interlayer module 3 towards the shrink wrapper 2 and the output module 4 until it is adjacent to the output module. The material M is drawn between the two platens of the output module by pushing the plastic film curtain according to the known principle of a shrink wrapper ( figure 10 ).

[0074] The means of displacement 5 then cause the movement of the intercalated module 3 towards the compression module 1, so as to again maintain the functional gap E between the intercalated module 1 and the output module 4 ( figure 11 ).

[0075] At this stage, the detection sensor 6 sends a signal to the control unit 7 indicating that the functional space E is present. The control unit then commands the movement of the lower sealing bar 22 and the upper sealing bar 23 so that they meet and perform a weld, in this case a double weld, and a cut of the upper plastic film with the lower plastic film ( figure 12 ).

[0076] As illustrated by the figures 7 à 12It should be noted that, according to the present embodiment, the compression module 1 and the interlayer module 3 are sized to receive two batches of material M spaced apart. The mobility of the interlayer module 3 relative to the compression module 1, on the one hand, and relative to the shrink wrapper 2 and the output module, on the other, allows for a kind of buffer zone whereby the first batch of material M, in the direction of travel D, is introduced into the shrink wrapper 2 while the other batch of material M remains within the interlayer module 3. During this time, it is possible to admit two new batches of compression material M into the compression module 1 and compress them. This compression phase can be carried out while the batch of material M remaining in the interlayer module is being transferred through the output module. The new batches of material M, in their compressed state, can then be transferred into the now-vacant interlayer module 3.

[0077] This type of operation allows for a high production rate.

[0078] Furthermore, as previously mentioned, this output module incorporates lateral heating means designed to induce shrinkage of the (polyethylene) film on the lateral sides of the material. In the embodiment where two batches of material are admitted simultaneously into the compression module, the line modules are synchronized, allowing, in particular, during the phase when both batches of material are in the output module, for the film to be shrunk on one of the two batches while it is kept compressed, and for it to remain compressed after exiting the output module.

Claims

1. A packaging line for a compressible material (M) in plastic film, comprising: - a material compression module (1), comprising a lower compression plate (10) and an upper compression plate (11) movable in height relative to one another from an intake position of the material in an uncompressed state to a closer position intended to convey the material in a compressed state; - a bundling machine (2), extending from the compression module (1) in a material feed direction so as to bundle the material in a compressed state, - an output module (4), immediately extending from the bundling machine (2) in a material feed direction, comprising a lower output plate (40) and an upper output plate (41) spaced apart from one another in height so as to keep the material in a compressed state, - an interposed module (3) disposed between the compression module (1) and the bundling machine (2) so as to be able to arrange a functional gap (E) with the output module (4), the interposed module (3) comprising a lower interposed plate (30) and an upper interposed plate (31) spaced apart from one another in height so as to keep the material in a compressed state, characterised in that it comprises movement means (5) of the interposed module (3) relative to the compression module (1) and / or relative to the output module (4), the movement means (5) being controlled so that the interposed module (3) is contiguous to the compression module (1) and arranges the functional gap with the output module (4), the functional gap being capable of allowing the passage of an upper plastic film, a lower plastic film and means for sealing the upper plastic film with the lower plastic film to create a film screen, or, alternatively, so that the interposed module (3) is contiguous to the output module (4) and arranges a space with the compression module (1).

2. The packaging line for a compressible material in plastic film according to claim 1, characterised in that the compression module (1) is fixed and in that the interposed module (3) is movable relative to the compression module (1) in a material feed direction.

3. The packaging line for a compressible material in plastic film according to claim 1, characterised in that the bundling machine (2) is fixed and in that the interposed module (3) is movable relative to the bundling machine (2) in a material feed direction.

4. The packaging line for a compressible material in plastic film according to any one of the preceding claims, characterised in that the lower interposed plate (30) and the upper interposed plate (31) are aligned in height respectively with the lower compression plate (10) and the upper compression plate (11) when they occupy the closer position.

5. The packaging line for a compressible material in plastic film according to claim 4, characterised in that the lower interposed plate (30) and the upper interposed plate (31) are aligned in height respectively with the lower output plate (40) and the upper output plate (41).

6. The packaging line for a compressible material in plastic film according to any one of the preceding claims, characterised in that the lower compression plate (10) carries a first conveyor (100) of the material in a material feed direction.

7. The packaging line for a compressible material in plastic film according to any one of the preceding claims, characterised in that the lower interposed plate (30) carries a second conveyor (300) of the material in a material feed direction.

8. The packaging line for a compressible material in plastic film according to any one of the preceding claims, characterised in that the lower output plate (40) carries a third conveyor (400) of the material in a material feed direction.

9. The packaging line for a compressible material in plastic film according to claim 1, characterised in that it comprises a sensor (6) for detecting the functional gap between the interposed module (3) and the output module (4), and in that it also comprises a control unit (7) capable of receiving a signal of presence of the functional gap from the sensor (6) for detecting the functional gap, the control unit (7) being configured to actuate a movement and sealing by the sealing means after receiving the signal of presence of the functional gap.

Images