EP0633187A1 - Automatic packaging machine using a foil provided with a closure strip, and package - Google Patents

Abstract

The present invention relates to a machine for automatically forming packaging based on films (10) which are equipped with strips (12), comprising a forming neck (200), a filling chute (300), means (600) for longitudinal welding and means (700) for transverse welding, characterised in that the machine includes means (400) for localised pre-welding of the strips (12), which pre-welding means (400) are offset angularly with respect to the longitudinal welding means (600), and the machine includes means (500) for guiding the strips (12), located upstream of the pre-welding means (400). The present invention also relates to the packages thus obtained. <IMAGE>

Description

The present invention relates to the field of machines for automatically forming, filling and closing packaging based on films of thermoplastic material comprising profiles, in particular complementary male and female zipper profiles.

As described in documents US-A-4,894,975, US-A-4,876,842, US-A-5,046,300 and US-A-5,127,208, most of the known automatic machines for forming, filling and the closure of packaging based on a film of thermoplastic material is supplied with a film of constant flatness and furthermore comprises means for supplying complementary male and female zipper profiles as well as means capable of fixing by welding profiles on the film.

These machines generally include a forming neck which receives the film in the planar state from an unwinder and provides the film-shaped tube at the outlet, a filling chute which opens into this forming neck and consequently into said tube, longitudinal welding means for closing the tube longitudinally and means capable of sequentially generating a first transverse weld before a product is introduced into the tube by the filler neck, then a second transverse weld when the product has been introduced into the tube to close a package around it. The means for fixing the profiles to the film, generally by welding or even by bonding or any equivalent means, are generally provided downstream of the forming neck.

These machines have already done great service.

However, they are not entirely satisfactory. In particular the means for supplying complementary male and female zipper profiles and the means for fixing by welding these profiles on the film are generally of fairly complex structure. Furthermore, the production rate of these machines is limited by the structure of these means and by the synchronization required between the film and the closure profiles.

In an attempt to improve the situation, it has already been proposed to use a film pre-equipped with complementary male and female zipper profiles as described for example in document FR-A-2 583 018.

However, these attempts have so far not been entirely satisfactory either.

In particular, the Applicant has found that due to the extra thickness formed by these profiles on the film, guiding the latter along the machines is difficult to achieve and the maximum rate of manufacture of packaging with such films is limited.

The present invention now aims to improve existing automatic machines.

• la machine comporte des moyens de pré-soudure localisée des profilés au niveau des soudures transversales réalisées ultérieurement, lesquels moyens de pré-soudure sont décalés angulairement par rapport aux moyens de soudure longitudinale, et
• la machine comporte des moyens de guidage des profilés situés en amont des moyens de pré-soudure.

This object is achieved in the context of the present invention, thanks to an automatic forming, filling and closing machine for packaging based on films of thermoplastic material provided with profiles, in particular with complementary male and female zipper profiles, which comprises a forming neck which receives the film in the generally flat state as an input from an unwinder and provides the film shaped tube as an outlet, a filling chute which opens into this forming neck and consequently into said tube , longitudinal welding means for closing the tube longitudinally and means capable of sequentially generating a first transverse weld before a product is introduced into the tube by the filler neck, then a second transverse weld when the product has been introduced in the tube to close a package around it, characterized by the fact that:

• the machine comprises means for localized pre-welding of the profiles at the level of the transverse welds produced subsequently, which pre-welding means are angularly offset with respect to the longitudinal welding means, and
• the machine includes means for guiding the profiles located upstream of the pre-welding means.

According to another advantageous characteristic of the present invention, the film is pre-equipped, at the entrance to the machine, with profiles placed at a distance from its lateral edges.

According to an advantageous characteristic of the present invention, the means for guiding the profiles comprise on the one hand means for external guiding of the film equipped with the profiles, on the other hand a spacer placed inside the tube formed by the film after the forming neck.

According to another advantageous characteristic of the present invention, the machine also comprises means for guiding the profiles at the entrance to the forming neck.

The present invention also covers the packaging obtained with such a machine.

• la figure 1 représente une vues schématique partielle en perspective d'une machine conforme à la présente invention,
• la figure 2 représente schématiquement des moyens de guidage prévus en amont du col de formage conformément à la présente invention,
• la figure 3 représente une vue en coupe transversale horizontale d'une machine conforme à la présente invention au niveau des moyens de guidage des profilés situés en amont des moyens de pré-soudure,
• la figure 4 représente une vue en coupe transversale horizontale partielle du film au niveau des moyens de soudure longitudinale et illustre un positionnement correct du film obtenu grâce aux moyens de guidage conformes à la présente invention,
• les figures 5 et 6 représentent des vues en coupe transversales horizontales partielles du film similaires à la figure 4 et illustrent le risque de mal-positionnement du film au niveau des moyens de soudure longitudinale en l'absence des moyens de guidage conformes à la présente invention,
• la figure 7 représente une autre vue en coupe transversale horizontale partielle du film au niveau des moyens de présoudure des profilés et illustre un positionnement correct du film obtenu grâce aux moyens de guidage conformes à la présente invention, et
• la figure 8 représente une autre vue en coupe transversale horizontale partielle du film similaire à la figure 7 et illustre le risque de mal-positionnement du film au niveau des moyens de présoudure des profilés en l'absence des moyens de guidage conformes à la présente invention.

Other characteristics, objects and advantages of the present invention will appear on reading the detailed description which follows and with reference to the appended drawings, given by way of nonlimiting example and in which:

• FIG. 1 represents a partial schematic perspective view of a machine according to the present invention,
• FIG. 2 schematically represents guide means provided upstream of the forming neck in accordance with the present invention,
• FIG. 3 represents a horizontal cross-sectional view of a machine according to the present invention at the level of the means for guiding the profiles situated upstream of the pre-welding means,
• FIG. 4 represents a partial horizontal cross-sectional view of the film at the level of the longitudinal welding means and illustrates a correct positioning of the film obtained thanks to the guide means in accordance with the present invention,
• Figures 5 and 6 show partial horizontal cross-sectional views of the film similar to Figure 4 and illustrate the risk of mis-positioning of the film at the longitudinal welding means in the absence of the guide means according to the present invention ,
• FIG. 7 shows another view in partial horizontal cross-section of the film at the level of the profile pre-sealing means and illustrates a correct positioning of the film obtained thanks to the guide means in accordance with the present invention, and
• FIG. 8 represents another view in partial horizontal cross-section of the film similar to FIG. 7 and illustrates the risk of mis-positioning of the film at the level of the profile pre-sealing means in the absence of the guide means in accordance with the present invention .

In the context of the detailed description which follows, the aim will essentially be to produce packaging using films of thermoplastic material provided with complementary male and female zipper profiles. However, the present invention is not limited to the use of this particular type of profile. It extends to all types of profiles capable of equipping a packaging film, such as for example cords integrated into the film to facilitate the opening thereof, decorative borders, for example colored borders, or even graduated borders for identifying the volume of product contained in the packaging.

• des moyens 100 d'alimentation en film 10 prémuni de profilés 12 de fermeture à glissière mâle et femelle complémentaires,
• un col de formage 200,
• une goulotte de remplissage 300,
• des moyens 400 de pré-soudure des profilés 12,
• des moyens 500 de guidage placés en amont des moyens de pré-soudure 400,
• des moyens 600 de soudure longidutinale,
• des moyens 700 de soudure transversale, et
• des moyens 800 d'entrainement du film 10.

The machine according to the present invention, for automatically forming, filling and closing packages based on films of thermoplastic material, shown in FIG. 1 appended, essentially comprises:

• means 100 for supplying film 10 provided with complementary male and female zipper profiles 12,
• a forming collar 200,
• a filling chute 300,
• means 400 for pre-welding the profiles 12,
• guide means 500 placed upstream of the pre-welding means 400,
• means 600 for longitudinal welding,
• means 700 for transverse welding, and
• means 800 for training the film 10.

Preferably, in the context of the present invention, means 900 for guiding the profiles 12 shown in FIG. 2 are also provided upstream of the forming neck 200.

The supply means 100 can be formed of any suitable known structure capable of receiving a roll of film of thermoplastic material 10 provided with complementary male and female zipper profiles 12 and supply this film to the forming neck 200 with a tension that is substantially constant. At the entrance to the forming neck 200, the complementary male and female closure profiles are engaged one inside the other.

As can be seen in FIG. 1, preferably the profiles 12 are placed at a distance from the longitudinal edges 14, 15 of the film 10, parallel to these.

The film 10 provided with profiles 12 can be obtained using any technique known to those skilled in the art. This film 10, as well as the sections 12 and their process for obtaining will not be described in more detail below.

As can be seen in FIG. 1, at the entry 204 of the forming neck 200, the film 10 is generally plane and arranged in a horizontal plane.

The forming neck 200 is preferably centered on a vertical axis 202. It has the function of transforming into a tubular blank, at its lower outlet 206, the flat film 10 which it receives at inlet 204. For this the forming neck 200 progressively brings the longitudinal edges 14 and 15 of the film closer together. These longitudinal edges 14 and 15 are placed side by side at the outlet 206 from the forming neck 200, as can be seen in FIG. 1. Thus at the outlet 206 from the forming neck 200 , the film 10 is in the form of a tubular blank centered on a vertical axis 202 and with longitudinal edges 14, 15 close together. This tubular blank moves down. Preferably at the outlet 206 of the forming neck 200, the longitudinal edges 14 and 15 are not glued against the tubular blank, but are detached from the latter. Very preferably, as can be seen in FIG. 1, the longitudinal edges 14 and 15 of the film are oriented in a vertical radial plane relative to the axis 202, at the outlet of the forming neck 200.

To this end, the forming neck 200 can be formed from any structure known to those skilled in the art, as described for example in the documents cited above.

The filling chute 300 is centered on the same vertical axis 202. It is superimposed on the forming neck 200 and opens into this forming neck 200 and therefore into the tubular blank formed at the outlet thereof.

The chute 300 is used to introduce the product to be packaged into the packages formed from the film 10.

The longitudinal welding means 600 are placed under the forming neck 200, facing the close longitudinal edges 14, 15 of the film 10. Their function is to heat weld the longitudinal edges 14, 15 of the film to close the tube longitudinally.

The longitudinal welding means 600 can be formed of any suitable structure known to those skilled in the art, such as for example two welding jaws 610, 620 elongated vertically, respectively on either side of the longitudinal edges 14 and 15 and driven cyclically in approach to allow the welding of the longitudinal edges 14 and 15 and in separation to allow the advancement of the film 10 under the effect of the drive means 800, as shown diagrammatically in FIG. 1, or also of a vertical welding jaw 610 cyclically displaced horizontally against a support tube 612 placed inside the film as seen in FIG. 3. This support tube 612 extends downward the filling chute 300.

In FIG. 1 attached, the longitudinal weld formed at the longitudinal edges 14 and 15 by the means 600 is referenced 602.

The transverse welding means 700 are in turn placed under the longitudinal welding means 600.

If necessary, additional shaping means, such as a horizontal slot, can be placed between the longitudinal welding means 600 and the transverse welding means 700 to flatten the tube formed by the film 10 before the latter reaches the transverse welding means 700.

The flattening of the tubular film is preferably carried out so that the closure profiles 12 originally placed at a distance from the longitudinal free edges 14 and 15 of the film 10 are found at a vertical edge of the flattened film. The longitudinal weld 602 produced previously is then placed over the width of the flattened film as seen on the bottom of FIG. 1.

The transverse welding means 700 are designed to sequentially generate a first transverse weld 702 before a product is introduced into the tube by the filler neck 300, then a second transverse weld 704 when the product has been introduced into the tube, to close a package around it, as seen at the bottom of Figure 1.

More precisely, said second transverse weld 704 for a given package serves as the first weld 702 for the following packaging and so on, the packages then being separated at the level of these transverse welds as seen in FIG. 1.

The transverse welding means 700 can be formed of any suitable structure known to those skilled in the art, such as for example two welding jaws 710, 720 stretched horizontally, respectively on either side of the flattened film and driven cyclically in approach to allow the production of welds 702 and 704 and in distance to allow the film 10 to advance under the effect of the drive means 800.

The packaging separation means can be formed by a guillotine integrated into these welding jaws 710 and 720 or by a guillotine placed downstream of these.

The drive means 800 can be formed by any suitable means known to those skilled in the art, such as for example belts or the like. For this reason these 800 training means have not been shown in Figure 1 to simplify the illustration.

The means 400 for pre-welding the profiles 12 have the function of locally crushing these profiles 12 at the level of future transverse welds 702 and 704, before the film arrives opposite the transverse welding means 700. This crushing by pre-welding profiles 12 is necessary to obtain correct transverse welds 702 and 704 over the entire width of the tubular film, if one wishes a perfect seal of the packages.

Preferably, these pre-welding means 400 are placed at the height of the longitudinal welding means 600.

The pre-welding means 400 can be formed of any suitable structure known to those skilled in the art, such as for example two welding jaws 410, 420 respectively disposed on either side of the region of the film 10 equipped with profiles 12 and cyclically driven in approach to allow the pre-weld and away to allow the advancement of the film 10 under the effect of the drive means 800.

The pre-welding means 400 are therefore angularly offset relative to the longitudinal welding means 600.

In FIG. 1 attached, the pre-welds thus produced are referenced 402.

The pitch of the pre-welds 402 corresponds to the length of the packages.

As indicated above, according to an important characteristic of the present invention, the machine comprises means 500 for guiding the closure sections 12, located upstream from the pre-welding means 400.

Very preferably, the means 500 for guiding the profiles 12 comprise on the one hand means 510 for external guide of the film 10 fitted with profiles 12, on the other hand a spacer 520 placed inside the tube formed by the film 10 at the outlet of the forming neck 200.

More precisely still according to the preferred embodiment shown in the appended figures, the external guide means 510 comprise a plate 512 and a rod 514.

The plate 512 is arranged vertically. It laterally supports the film 10 at the level of the profiles 12. More specifically, the plate 512 avoids the offset of the film 10 and of the profiles 12 clockwise according to the representation in FIG. 3.

The rod 514 comprises two wings 515 and 516 folded into an "L" at 90 °. The first wing 515 generally horizontally is fixed by any appropriate means to the plate 512. This wing 515 radially outwardly limits the loop of the film 10 provided with the profiles 12 formed projecting from the tubular blank. The second wing 516 extends in a vertical plane parallel to the plate 512, in proximity to said tubular blank. It supports the film 10 laterally on the other side at the level of the profiles 12. More precisely, the rod 514 avoids the offset of the film 10 and the profiles 12 anticlockwise as shown in FIG. 3.

Finally, the spacer 520, placed inside the tube formed by the film 10, at the outlet of the forming neck 200, consists of a vertical blade fixed on the aforementioned support tube 612. As can be seen in FIG. 3 appended, the spacer 520 makes it possible to maintain the profiles 12 detached from the internal support tube 612. Typically, but not limited to, the radial extension of the spacer 520 projecting from the outer periphery of the tube support 612 is of the order of 5 mm.

Very preferably the retractor 520 is fixed in a groove 614 formed in the support tube 612 as seen in Figures 3, 7 and 8. More specifically still the spacer 520 is preferably fixed in an adjustable manner vertically against the bottom of the groove 614, for example at the using screws or any equivalent means, to allow the spacer 520 to be positioned in the appropriate place, which is a function of the position of the pre-weld, itself a function of the length of the finished package.

Very advantageously, the guide means 500 and the pre-sealing means 400 are mounted on a common support assembly capable of rotation about a vertical axis to facilitate access to these means 400, 500, for their maintenance, control, cleaning and adjustment.

As seen in the comparative examination of FIG. 4 (which shows the overlap of the longitudinal edges 14 and 15 obtained with guide means 500 in accordance with the present invention) and of FIGS. 5 and 6 appended (which show overlaps of longitudinal edges obtained without the guide means 500 according to the present invention), the machine according to the present invention allows a regular and precise covering of the longitudinal edges 14 and 15 of the film capable of providing a longitudinal weld 602, regular, reliable, waterproof and aesthetic.

Furthermore, as can be seen on a comparative examination of FIGS. 7 (with spacer 520 according to the present invention) and 8 (without spacer), spacer 520 makes it possible to guarantee precise positioning of the profiles 12 inside the jaws. of pre-welding 410 and 420 suitable for allowing correct crushing of the profiles 12 in order to subsequently obtain a satisfactory and tight transverse weld at the level of the means 700.

As indicated previously according to another advantageous characteristic of the present invention, the machine also preferably includes means 900 for guiding the profiles 12 at the entry of the forming neck 200.

A preferred embodiment of these guide means 900 is shown in Figure 2 attached. according to this embodiment, the guide means 900 comprise an arm 910 pivotally mounted about a generally horizontal axis 912, parallel to a tangent to the forming neck 200 at the level of the profiles 12.

This arm 910 carries two rollers 920 and 922 mounted for rotation on the arm 910 about an axis 921 parallel to the axis 912. The rollers 920 and 922 are adapted to rest on the film 10 which passes over the forming neck 200 , respectively on either side of the sections 12. For this purpose the rollers 920 and 922 are separated from each other by an intermediate day 924 adapted to the width of the sections 12. In practice the two rollers 920 and 922 can be produced in the form of a unitary cylinder provided with an annular groove 924 at mid-width.

Such guide means 900 make it possible to correctly position the film 10 at the entrance to the neck 200 and thus to create a cylinder whose closure profiles 12 are in the appropriate place.

The machine according to the present invention has many advantages over known prior machines.

It has a simple structure and avoids the use of complex means for supplying separate profiles and the in situ fixing of these profiles on the film.

It allows high production rates for packaging.

It allows perfect guidance of the film without the risk of it being offset.

It allows automatic welding without defects and leads to packaging perfectly waterproof without the need for rework or subsequent verification.

It should be noted that the guide means 500 and 900 in accordance with the present invention can be supplied in the form of a kit capable of equipping existing automatic packaging machines to improve their efficiency and the quality of the packaging obtained.

Of course the present invention is not limited to the embodiment which has just been described but extends to any variant in accordance with its spirit.

In particular, as indicated above, the present invention can be applied to a large number of profile geometries 12, including to profile structures 12 associated with a cord integrated into the film to facilitate the opening of the latter. Such cords intended to allow, by traction, the cutting of the film 10 on the outside of the profiles 12, are well known to those skilled in the art. They are generally called "easy open" in Anglo-Saxon language. In the context of the present invention, such beads are placed at the top 17 of the loop 16 formed projecting from the support tube 612 by the spacer 520, that is to say in position adjacent to the wing 515 of the rod 514.

Furthermore, according to the preferred embodiment previously described, the film 10 is pre-equipped with profiles 12 at the entrance to the machine.

However, as a variant, it is possible to envisage feeding the packaging machine using film 10 and separate profiles 12, subject to equipping said machine with means for fixing the profiles 12 on the film 10.

Claims (14)

Machine for automatically forming, filling and closing film-based packaging (10) made of thermoplastic material provided with profiles (12), in particular complementary male and female zipper profiles, comprising a forming collar (200) which receives at the input the film (10) in the generally planar state coming from an unwinder and provides at the output the film (10) shaped as a tube, a filling chute (300) which opens into this forming neck (200) and consequently in said tube, means (600) for longitudinal welding to close the tube longitudinally and means (700) capable of sequentially generating a first transverse weld (702) before a product is introduced into the tube by the chute filling (300), then a second transverse weld (704) when the product has been introduced into the tube to close a package around the latter,
characterized by the fact that: the machine comprises means (400) for localized pre-welding of the sections (12), which pre-welding means (400) are angularly offset relative to the longitudinal welding means (600), and - The machine comprises means (500) for guiding the profiles, located upstream of the pre-welding means (400). Machine according to claim 1, characterized in that the means (500) for guiding the profiles (12) comprise on the one hand means (510) for external guide of the film (10) equipped with the profiles (12), on the other hand a spacer (520) placed inside the tube formed by the film after the forming neck (200). Machine according to claim 2, characterized in that the means (510) for external guiding of the film comprise two elements (512, 514) capable of supporting respectively and laterally on either side a loop (16) of the film comprising the profiles (12). Machine according to claim 3, characterized in that the two elements are respectively formed by a vertical plate (512) and a rod (514), bent in L in the form of two orthogonal wings (515, 516), l 'One fixed on the plate (512), the other located in a vertical plane to support the loop (16) of the film. Machine according to one of claims 2 to 4, characterized in that the spacer (520) is formed by a vertical blade. Machine according to one of claims 2 to 5, characterized in that the spacer (520) is vertically adjustable on a central vertical support (612). Machine according to one of claims 1 to 6, characterized in that the guide means (500) are pivotally mounted about a vertical axis on a support equipment. Machine according to one of claims 1 to 7, characterized in that it also comprises means (900) for guiding the profiles (12) at the entrance to the forming neck (200). Machine according to claim 8, characterized in that the means (900) for guiding the profiles (12) at the entrance to the forming neck (200) comprise an arm (910) pivotally mounted about an axis (912 ) generally horizontal and which supports two rollers (920, 922) able to rest on the film (10) at the level of the forming neck (200), which rollers (920, 922) are separated by an annular day (924) suitable for receive the profiles (12). Machine according to claim 9, characterized in that the arm (910) is pivotally mounted about an axis (912) parallel to a tangent at the forming neck (200) at the level of the bearing zone of the rollers (920, 922) on the film (10). Machine according to one of claims 1 to 10, characterized in that the film (10) is pre-equipped, at the entrance to the machine, with profiles (12) placed at a distance from its longitudinal lateral edges (14, 15) . Machine according to one of claims 1 to 11, characterized in that it comprises means for supplying a separate profile (12) and means for fixing the profile (12) to the film. Machine according to one of claims 1 to 12, characterized in that the profiles are chosen from the group comprising: complementary male and female zipper profiles, pull-out cords, trim edges, in particular the colored borders, and the graduated borders making it possible to appreciate the volume of product contained in the packaging. Packaging obtained using a machine according to one of claims 1 to 13.

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