FR2822132A1 - Method of applying heat shrinkable sleeve on packaging comprises placing sleeve around packaging, locally retracting it in first and second locations and plunging into medium at homogenous temperature - Google Patents

Abstract

The method comprises placing the sleeve (6a) around the packaging (5b) and locally retracting the sleeve to fix it to the packaging in a first location (8). The sleeve is then partially retracted in a second location (7) spaced from the first to form a narrowing section. The packaging and the sleeve are together plunged into a medium (9-11) at a homogeneous temperature so as to radially shrink the sleeve and completely apply it against the packaging without forming folds or irregularities. An Independent claim is included for a packaging with heat shrinkable sleeve obtained by the method

Description

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 The invention relates to a method of applying a heat-shrinkable sleeve to a package, as well as to a device for carrying out the method, as well as to a package coated with a heat-shrinkable sleeve using a method according to the invention.

 Numerous methods and apparatus are known for applying a heat-shrinkable sleeve to a package. Generally, the heat-shrinkable sleeve is threaded around the packaging to be coated, then heat-shrinking is carried out by applying heat to the sleeve. After complete heat-shrinking, the heat-shrink sleeve is secured to the packaging.

 This known technique is satisfactory in the case where the packages to be coated have a regular shape, for example cylindrical or prismatic.

 However, in the case of packages of irregular shapes, such as flasks, bottles, or other containers having a variable section, the known technique is not satisfactory, due to the formation of folds, crevices or various undesirable irregularities, in especially in the case of printed sleeves.

 Indeed, in the case of printed or decorated sleeves, any deformation of the sleeve during heat shrinking or any undesirable irregularity is detrimental to the final presentation of the coated packaging. Irregularly coated packaging must then be removed from the production line and undergo difficult and costly manual processing.

 An object of the invention is to improve the known prior art, by allowing the application of heat-shrinkable sleeves on packages, even of variable section, ensuring precise and repetitive positioning of the sleeves and thus avoiding discarded or manual processing of poorly coated packaging.

 The subject of the invention is a method of applying a heat-shrinkable sleeve to a package, comprising in combination the following steps: a). put the sleeve around the packaging, b). retract the sleeve locally to secure it to the packaging in a first location and partially retract the sleeve in a second

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 location spaced from said first location to form a section constriction, c). immerse the packaging and the sleeve joined together in a medium at a predetermined homogeneous temperature, so as to radially retract the sleeve to apply it completely against the packaging without the formation of folds or undesirable irregularities.

 According to other alternative characteristics of the invention: - the medium at a predetermined homogeneous temperature is a water bath comprising a tank filled with simmering liquid at a temperature below the boiling temperature, - the medium at a predetermined homogeneous temperature is a dry water bath comprising cavities suitable for the passage of the package (s) to be coated, the dry water bath can be a hot air water bath comprising at least one temperature-controlled zone.

 The invention also relates to a device for applying a heat-shrinkable sleeve to a package, comprising a sleeve fitting station around the package, characterized in that the device comprises means for locally shrinking the sleeve for the secure to the packaging at a first location and means for partially retracting the sleeve at a second location spaced from said first location to form a section constriction, as well as means for immersing the packaging and the sleeve secured to each other in a medium at a predetermined homogeneous temperature, so as to radially retract the sleeve to apply it completely against the packaging without the formation of folds or undesirable irregularities.

 According to other alternative characteristics of the invention: the device comprises a medium at homogeneous temperature, for example a liquid water bath, in which the packaging and the sleeve are joined together,

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 - the device comprises a homogeneous temperature medium, for example a dry water bath, so as not to wet the packaging, - the device comprises a means of transfer of packaging between different stations for implementing the process steps , - the packaging transport means can be a packaging gripping means in the upper part of the packaging.

 The invention finally relates to a packaging or similar object coated with a heat-shrunk sleeve using an application method according to the invention.

 The invention will be better understood thanks to the description which follows given by way of nonlimiting example with reference to the appended drawings in which: - Figure 1 schematically shows a side elevation view of a first embodiment of the invention.

 - Figure 2 schematically shows a side elevational view of a second embodiment of the invention.

 - Figures 3 to 5 schematically represent essential successive steps of the method according to the invention.

 - Figure 6 schematically shows a partial sectional view through a vertical plane of a device part according to the invention.

 FIG. 7 schematically represents a top view in the direction of arrow VII of FIG. 6 of the part of the device according to the invention of FIG. 6.

vertical d'une variante de partie de dispositif de mise en oeuvre de l'invention. - Figure 8 shows schematically a sectional view through a plane

vertical of a variant of the device for implementing the invention.

With reference to FIG. 1, a method according to the invention can be executed by combination of manual steps and automated steps.

In the simplified version, an implementation device of the invention essentially comprises a transfer means, for example a transfer means of the conveyor roller motorized type, local heating means, and a means for uniform application of temperature. , for example a double boiler with agitator.

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The conveyor comprises several rollers la, lb, lc, Id, le, If, 1g, lh, at least some of which are motorized to start a conveyor belt 2 in the direction of the arrows 3. The rollers la to lh and the conveyor belt 2 are preferably supported by a frame 4 of a type known per se provided with suitable height-lifting jacks.

 At least one bottle 5a is placed on the strip 2 by an operator, to be transported by successively carrying out the steps of the method according to the invention.

 In the next step, a bottle 5b is in the position for receiving a sleeve 6a, so as to thread the sleeve 6a around the bottle. The fitting of the sleeve 6a on the bottle 5b can be manual or automated. For the automation of the installation, it is possible to provide a unitary installation of the sleeve, or an installation from one or more rollers of the sleeve and an associated apparatus for cutting out one or more sleeves from the material wound on the roll.

 After this operation, the bottle 5c is coated with the sleeve 6a which is not heat-shrunk.

 In the next step, an energy source is locally applied at two ends spaced from the sleeve placed on the bottle. In this alternative embodiment, the bottle 5d becomes integral in its lower part with the sleeve 6b retracted lower by an energy source so as to be secured to the bottle 5d, and remains spaced from the upper end of the sleeve 6b.

 This upper end of the sleeve 6b undergoes partial retraction by another source of energy, so as to reduce the section of the sleeve by forming a constriction.

 The application of the heat sources shown diagrammatically by the arrows 7 and 8 to the two ends of the sleeve 6b can be manual or automated. Advantageously, two jets of hot air are used at a temperature between 100 and 600 ° C. to effect the retraction at the ends of the sleeve 6b. In an automated variant, it is possible to provide a turntable ensuring rotation of the bottle during retraction by the heat sources applied in 7 and 8. As a variant, the energy sources applied in 7 and 8 may also include a source water

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 hot or hot steam or hot gas, or a radiant element, such as a radiant resistor or an infrared emitter.

 The main thing is that the retraction at 7 and 8 is ensured in a substantially uniform manner by carrying out a relative rotation of the bottle relative to the heat sources 7 and 8 or by applying a homogeneous heat on the periphery of the container in the direction of the height without rotating the container, for example by means of a heating ring surrounding the periphery of the container.

 After this pre-shrinking step, leading to the formation of a sleeve 6b in the form of a chimney secured at its lower end to the bottle 5d, the assembly of the sleeve and the bottle is moved in a water bath, comprising by example a tank 9, an agitator 10, and a heating resistor 11 regulated in temperature.

 The level of the bain-marie is determined so as not to allow water to enter through the neck of the bottle and to obtain complete warming up of the entire height of the sleeve 6b.

 The temperature of the water bath is kept homogeneous, by the action of the agitator 10 and by the temperature regulation of the heating by means of the resistor 11. Preferably, the water of the water bath is kept warm, in the vicinity lower of the boil. To avoid unwanted deposits of limescale or other precipitates, the water in the water bath is preferably demineralized water, or of equivalent purity.

 Tests have shown that the water regulation temperature is advantageously greater than 90, and preferably between 92 and 98 C, so as to avoid any boiling of the water liable to affect the quality of the shrinkage of the water. muff.

 In the case of closed or filled bottles or packaging having a density greater than that of water, it suffices to hold the bottle by lowering it gradually into the water using any handling means shown diagrammatically by the arrow 12, or manually by moving in the direction of arrow 12.

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 The vertical movement of the bottle down into the hot water bath produces a clear, gradual and uniform retraction of the sleeve on the packaging, until complete retraction.

 The air trapped between the upper part of the sleeve 6b and the body of the bottle 5d is expelled upwards by the combined action of the pressure and the temperature of the hot water of the water bath. It is surprisingly found that this flushing of air trapped between the bottle and the sleeve produces a smoothing of the sleeve, thereby improving the quality of the retraction and the final appearance. Indeed, the film of the sleeve is then subjected to a vertical stress due to the flushing of the air and a radial stress due to the shrinkage, which produces an effect of vertical tension on the film of the sleeve and prevents any formation of folds. .

 The invention can be applied to sleeves made of all kinds of heat-shrinkable materials, commonly called by those skilled in the art "memory materials". The invention can in particular be applied to sleeves made of the following materials: polyester (PET), polyvinyl (PVC), styrenics (PS), olefins (PP, PE) and other equivalent materials - with a transverse retraction rate of less than 80 % and a longitudinal retraction rate less than 2%.

 The invention can be applied to variable thicknesses of material, in particular to thicknesses of material between 30 micrometers and 80 micrometers.

 After complete retraction of a sleeve 6c on a bottle 5e, the bottle 5e coated with the sleeve 6c is extracted manually or by a handling means in the direction of arrow 13 and is ready to be removed from the conveyor belt, to optionally pass into a drying unit in the event that traces of remaining water have to be removed.

 After leaving a drying unit not shown and of a type known per se, the bottles can lead to an accumulation belt or to the line of a bottling line not shown.

 Referring to Figure 2, a pallet 14 supports a set of bottles 15a.

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 The plurality of bottles 15a is intended to be gripped by a handling means A capable of gripping and holding the bottles by the neck.

 The handling means A is provided, in the example shown, to grab six bottles 15b on a pallet 14, transport them, and move them in the direction of arrow B to a presentation table where bottles 15c are placed previously moved.

 A set of reels 16, for example rolls or stacks of sleeves, is controlled so as to release six sleeves 16a to place them on the bottles 15c.

 The handling means A then takes up the bottles 15c surrounded by the sleeves 16a not yet retracted, to move them in the direction of the arrow C and place them at a predetermined height relative to heat sources 17,18, on suitable rotating supports to drive the bottles 15c surrounded by the sleeves 16a in rotation relative to the heat sources 17 and 18. The driving in rotation of the bottles 15c surrounded by the sleeves 16a is advantageously carried out by rotating plates 19, motorized separately or driven simultaneously by a gear train. Other means for driving the bottles 15c in rotation equivalent to rotary plates can be used for implementing the invention.

 At this stage, the lower heat source 17 retracts the lower end of each sleeve 16 a to secure this lower end to the bottle 15c, while an upper heat source 18 performs partial heat shrinkage of the end upper of a sleeve 16a.

 After this step, the handling means A takes up the bottles 15d coated with sleeves 16b partially retracted in the form of a chimney, for transporting the bottles in the direction of arrow D to a water bath 20 comprising a tank, a heating resistance 21 regulated in temperature and an agitator 22. The handling means A can, in the case of packaging or empty bottles, apply a vertical force to these packaging or empty bottles to balance the buoyancy, and apply the bottles to the bottom of the water bath until the sleeves are fully retracted.

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 After leaving the water bath, the sleeves 16c fully retracted and the bottles 15e are directed to a drying means, for example a drying tunnel, not shown and of a type known per se.

 With reference to FIGS. 3 to 5, the essential steps of the method according to the invention are the steps of threading a sleeve around a package, for example a bottle 5, so as to position a sleeve 6 at a relative height chosen in relation to bottle 5 (Figure 3).

 In the next step of the process, at two places spaced at the two ends of a sleeve 6, a complete retraction is made at the lower end to secure the sleeve 6 to the bottle 5 and a partial retraction at the upper end, so as to form a chimney or equivalent conformation.

 These two different types of retractions can be obtained by applying 7 or 8 of various energy sources: blowing pulsed hot air, steam jet, soaking the lower end in hot liquid, or local application of infrared radiation. or others using radiant panels, or local application of radiation using a radiant resistor (Figure 4).

 The phase of shaping by heat-shrinking described in FIG. 4 is followed by a phase consisting in immersing the bottle or the packaging 5 equipped with the chimney-shaped sleeve in a medium at homogeneous temperature making it possible to obtain a clear retraction and complete of the sleeve 6 on the packaging 5, to obtain the sleeved packaging shown in FIG. 5.

 By way of example, a homogeneous temperature medium for implementing the invention can consist of a water bath of the type described with reference to FIG. 1 or to FIG. 2.

 However, in the case of a wet type water bath described with reference to Figures 1 and 2, it is necessary to provide a natural or accelerated drying phase, which may be undesirable in the case of bottles or product packaging. for pharmaceutical use, or to have a very high degree of purity in corresponding biological or technological applications.

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 The invention also extends to the case where the medium of homogeneous temperature is obtained without bringing the wall of the packaging or the sleeve into contact with a liquid.

 With reference to FIGS. 6 and 7, another variant of a bain-marie according to the invention is designated as a whole by 30 and comprises an enclosure containing a liquid L capable of transmitting heat, subjected to the action of a heating resistor 31 and an agitator 32, so as to heat the liquid L in a regulated and homogeneous manner.

 Due to the regular and homogeneous heating of the liquid L, the interior of the enclosure containing the liquid L is at a uniform temperature.

 The enclosure 33 is made in the form of a tank comprising cavities 34 of cylindrical shape integral with the cover of the enclosure 33. Each cavity 34 has a closed bottom, so as to prevent any penetration of the liquid L inside the cavity . The temperature of the walls of each cavity 34 is close to or slightly lower than the temperature of the liquid L.

 When the bottles carried by a handling means A and each coated with a chimney-shaped sleeve are inserted into the cavities 34, these bottles undergo in the direction of descent a vertical temperature gradient in the opposite direction simultaneously causing a radial retraction and a slight vertical stretch of the sleeve surrounding each bottle.

 Thus, thanks to this variant of the invention, it is possible to obtain the same effects as with the water baths described with reference to Figures 1 and 2, while avoiding having to dry wet packaging. In the remainder of the present application, this type of homogeneous temperature well containing no liquid is called "dry water bath".

 This variant of the invention is preferred in the case where the corresponding applications require a thorough control of the cavity and a microbiological or bacteriological quality excluding the presence of hot water.

 With reference to FIG. 8, another variant of a bain-marie known as a "dry bain-marie" constituting a part of the implementation device of the invention comprises a box 40 subdivided into several zones 41,42, 43,44 separated vertically by

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 partitions or appropriate dividers. Each zone 41 to 44 is subjected to the action of a jet of pulsed hot air or of a jet of dry steam or other gaseous jet produced by corresponding generators 45 to 48.

 The temperature of each zone 41 to 44 can be regulated independently and sequentially depending on the type of packaging or the type of sleeve intended to coat a particular packaging.

 When one plunges in the direction of arrow 49 a set of bottles or similar packages coated with a pre-shrunk chimney-shaped sleeve in zones 41 to 44, one obtains a progressive and clear retraction of the corresponding sleeves, which allows a presentation of printed patterns or decoration patterns without deformation and without undesirable irregularities.

 It is noted in particular, in the case of bottles of large shapes and welded sleeves, that the sleeves after application have a perfect alignment of their weld on a guide curve of the shape of revolution of the bottle. This alignment is a quality index of the regular application of the sleeve on the bottle, another index being the shiny and glossy appearance of the coating thus formed.

 The invention thus allows improved quality and significant savings for decorations of bottles or similar packaging, which hitherto had to be printed or transferred directly to the outer surface of the packaging.

 The invention also makes it possible to eliminate irregular applications, sources of ineffectiveness leading to recycling of packaging and possibly loss of content.

 The invention finally makes it possible to obtain excellent reproducibility ensuring a homogeneous appearance of the batches of packaging coated with sleeves thanks to the invention.

 The invention described with reference to several particular embodiments is in no way limited thereto, but on the contrary covers any modification of form and any variant embodiment within the scope and spirit of the invention.

Claims (10)

CLAIMS 1. Method for applying a heat-shrinkable sleeve to a package, comprising the following steps in combination: a). place the sleeve (6a, 16a) around the packaging (5b, 15c), b). locally retract the sleeve (6a, 16a) to secure it to the packaging (5b, 15c), in a first location (8,17) and partially retract the sleeve in a second location (7,18) spaced from said first location ( 8,17) to form a section constriction, c). immerse the packaging and the sleeve joined together in a medium (9-11, 20-22, 34, 41-44) at a predetermined homogeneous temperature, so as to radially shrink the sleeve (6c, 16c) to apply it completely against the packaging (5th, 15th), without unwanted creases or irregularities.  2. Method according to claim 1, characterized in that the medium at a predetermined homogeneous temperature is a water bath (9-11) comprising a tank filled with simmering liquid at temperature below the boiling temperature.  3. Method according to claim 1, characterized in that the medium at a predetermined homogeneous temperature is a dry water bath comprising cavities (34) adapted to the passage of the package (s) to be coated.  4. Method according to claim 3, characterized in that the dry water bath is a hot air water bath comprising at least one zone (41 to 44) at controlled temperature.  5. Device for applying a heat-shrinkable sleeve to a package, comprising a sleeve fitting station around the package, characterized in that the device comprises means for locally shrinking the sleeve (6a, 16a) to secure it to the packaging (5b, 15c) at a first location (8,17) and partially retract the sleeve at a second location (7,18) spaced from said first location (8,17) to form a section constriction, as well as means for immersing the packaging and the sleeve joined together in a medium (9-11,20-22, 34,41-44) at a predetermined homogeneous temperature, so as to radially shrink the sleeve (6c, 16c) to apply it completely against the packaging without forming folds or undesirable irregularities. <Desc / Clms Page number 12>  6. Device according to claim 5, characterized in that the device comprises a medium at homogeneous temperature, for example a liquid water bath (9-11), in which the packaging and the sleeve are immersed together.  7. Device according to claim 5, characterized in that the device comprises a medium at homogeneous temperature, for example a dry water bath (30,41-44), so as not to wet the packaging.  8. Device according to claim 5, claim 6 or claim 7, characterized in that the device comprises a transfer means (2, A) for packaging between different stations for implementing the steps of the method according to one any of claims 1 to 4.  9. Device according to claim 8, characterized in that the transfer means (A) for packaging is a means for gripping packaging in the upper part of the packaging.

10. Packaging coated with a heat-shrunk sleeve, obtained directly by implementing a method according to any one of claims 1 to 4, or obtained by using a device according to any one of claims 5 to 9.