FR2733733A1 - Thermoplastic packaging sleeve manufacturing/printing procedure - Google Patents

Abstract

The procedure involves unrolling a thermoplastic film from a roll to form a continuous strip (2). The strip is passed through successive printing/decorating sections, and then coated with adhesive, folded over and held under tension to form a continuous sleeve. The adhesive can contain a surface-attacking solvent or be in the form of a pressure-sensitive substance. The adhesive is applied to the continuous strip in one or more lines by a spreader or a roller with a groove in it. Other rollers (30-32,34,35) fold the strip lengthwise and compress the resulting sleeve. The sleeve can then be cut into the required lengths by a blade (37).

Description

METHOD AND DEVICE FOR PRINTING AND
MANUFACTURE OF PACKING SLEEVES OR SLEEVES,
AND CORRESPONDING PRODUCTS
The invention relates to a process for printing and manufacturing packaging sleeves or sleeves, to a device for implementing this process and to sleeves or packaging sleeves obtained by implementing said method.

 I1 is known to provide hollow bodies such as bottles, aerosol cans and the like, in various materials, with a protective and decorative sleeve or sheath made of shrinkable plastic. This sleeve is loosely arranged around the container and, after heating causing the plastic to shrink, this sleeve fits perfectly around the container.

 The manufacture of these sheaths or sleeves consisted in carrying out a weld line all along the folded or close edges of a sheet of thermoplastic material oriented by stretching. The single welding or bonding lines thus formed thus make it possible to provide various receptacles or containers, sheaths or sheaths generally printed, in transparent or opaque thermoplastic material or also in porous or cellular plastic material.

 However, the presence of a single longitudinal weld line in the middle or more or less close to the edges of a continuous strip of sheath creates extra thicknesses during winding to such an extent that, during winding, the successive turns slide the one on the other in a disorderly fashion and take the form of an inverted V which can no longer be held on the winding mandrel. To overcome this first drawback, the document FR 2,300,736 describes a process in which the continuous and flat strip recovered at the end of manufacture is introduced into a box in the form of alternating folds in accordion and in such a way that the entry end and the last length of this strip in the box are located on the upper part when the box is full.

 When sections of sheaths or sleeves of heat-shrinkable plastic are used to enclose several articles in the same packaging, it is possible to observe deformations of the printed or decorated parts of the sheath due to the vacuum created between the articles during heat-shrinking or because that these articles have very different conformations.

To remedy this second drawback, the document
FR 2,491,886 proposes a packaging method in which the sleeve is divided beforehand into at least two compartments by welding or gluing the film on itself according to a generatrix of the sleeve.

 However, the single connection between several compartments by means of one or more single weld or bonding lines oriented longitudinally and therefore called "generators" has the disadvantage of allowing significant movements of an object relative to the neighboring object: the single welding or gluing line in fact forms a kind of hinge allowing significant movements of the packaged objects, which are frequently caused to move relative to each other, in their own compartment, due to tensile, shear or other forces during various manipulations. The document FR 2.637.866 proposes to carry out the welding or the gluing according to at least two generatrices of the sleeve in order to obtain two distinct lines of vertical connection between two compartments. However, this new arrangement does not solve the problem of regular winding, to which a solution was provided by the document FR 2.300.736.

 Indeed, in general, the fact of practicing single lines of welding or bonding according to a generatrix oriented longitudinally has the drawback that the sleeve thus formed has, after heat shrinking, roughness or spikes in relief at the line solder or single bond. These irregularities are on the one hand unsightly and on the other hand constitute zones of preferential rupture which do not ensure the inviolability of the product in the case where this technical function is sought.

 The invention aims to remedy these drawbacks of the known technique, by proposing a new printing and manufacturing technique for sleeves or packaging sleeves, allowing on the one hand the printing and the simultaneous manufacture of these sleeves and supplying on the other hand, after thermorétrdwb on, a particularly aesthetic packaging presenting no roughness and avoiding any deformation of the texts and patterns on the transparent plastic film.

 The subject of the invention is a process for printing and manufacturing sleeves or packaging sleeves, in which a reel of thermoplastic film is unwound to unwind a continuous strip and entrain it in successive printing or decoration sections. so as to print or decorate said continuous strip and then the continuous strip is coated by spreading on the strip an adhesive means, the coated strip is folded back on itself while keeping it under tension, so as to form a continuous sheath that the 'we extract by keeping it under tension.

According to other features of the invention
- the continuous strip is coated after leaving the last printing or decoration module,
the compression zone corresponding to the folding and closing of the continuous strip on itself is compressed,
- the continuous sheath formed is extracted by winding it in the form of a coil,
the continuous sheath formed is advanced so as to cut it by slicing into sleeves or individual packaging sleeves,
the adhesion means are spread over the continuous strip using a spreading member,
- The adhesion means are spread over the continuous strip using a roller comprising a hollow machining corresponding to the deposition of a predetermined shape on the continuous strip.

 A subject of the invention is also a device for printing and manufacturing sleeves for packaging sleeves, of the type comprising means for unwinding a reel for unwinding a continuous strip of shrink film, means for printing or continuous decoration of said strip, this device further comprising means for coating adhesion means, and means for folding down said strip to form a continuous sheath.

According to other features of the invention
the device comprises smoothing means,
the device comprises means for pressurizing,
the device comprises slicing means,
- The folding means comprise a shaper with several rollers.

 The invention finally relates to a sleeve or packaging sheath made from a shrink film folded over on itself and closed on lul-me by adhesion or by gluing to constitute at least one main sheath, the area of corresponding adhesion having a surface thickness of less than fifty micrometers and width greater than one and a half millimeters.

According to other features of the invention
- The adhesion means comprises a solvent carrying out a surface attack of the shrinkable film.

 - The adhesion means comprises an adhesive or a pressure-sensitive coating.

 - the sleeve has several compartments and several adhesion zones.

the sleeve has at least one incision,
- the sleeve has at least one transverse grip zone (A).

the sleeve has at least one pocket,
- The sleeve has at least one adhesion zone extending transversely and longitudinally.

The invention will be better understood from the description which follows given by way of nonlimiting example with reference to the accompanying drawings in which
Figure 1 schematically shows an elevational view of a printing machine and manufacturing sleeves or packaging sleeves according to the invention, illustrating the method according to the invention.

 FIG. 2 schematically represents in perspective a partial view of the outlet of a machine according to FIG. 1.

 FIG. 3 represents an explanatory sequence of steps of the printing and manufacturing process according to the invention.

 Figure 4 shows schematically in perspective a first embodiment of the sleeve according to the invention.

 Figure 5 shows schematically in perspective a second embodiment of the sleeve according to the invention.

 Figure 6 shows schematically in perspective a third embodiment of sleeves according to the invention.

 FIG. 7 schematically represents in perspective a fourth embodiment of a sleeve according to the invention manufactured according to the method described with reference to FIGS. 2 and 3.

 FIG. 8 schematically represents a view in longitudinal section of a sleeve described with reference to FIG. 7.

 FIG. 9 schematically represents in perspective a fifth embodiment of a sleeve according to the invention.

 Figure 10 schematically shows in perspective a sixth embodiment of the sleeve according to the invention.

 Figure 11 shows schematically in perspective a seventh embodiment of the sleeve according to the invention.

 FIG. 12 schematically represents an eighth embodiment of the sleeve according to the invention.

 FIG. 13 schematically represents a ninth embodiment of the sleeve according to the invention.

 Referring to Figure 1, a method according to the invention comprises the steps of unwinding from a reel 1 of thermoplastic film a continuous strip 2 of thermoplastic film so as to print this strip in a predetermined pattern in successive sections printing 3 and 4 or coating this strip of varnish at desired locations; coat the continuous strip 2 at the outlet of the last printing module 5 by spreading on the strip 2 an adhesion means contained in a container 6 supplying a pipe 7 connected to at least one spreading member 8 for example of the felt type or brush; fold the strip 2 under tension on itself by means of a shaping assembly 9 comprising several rollers so as to close the strip 2 on itself to form a continuous sheath 10 maintained under tension by extraction rollers 11 and pressurizing the adhesion zone corresponding to the closure of the film 2 on itself; and extract the continuous sheath 10 thus formed by winding it in the form of a coil 12 or by advancing it step by step by successive translations by means of a mechanism 13, by delivering it by means of a double guillotine 14 for the stack in piles 15 of individual sleeves ready for use.

 Thus, thanks to the invention, the printing and manufacture of the continuous sheath allowing the subsequent flow of sleeves or packaging sleeves in shrinkable material or the manufacture of sleeves or individual packaging sleeves are carried out simultaneously according to a continuous process. on a unitary device comprising printing or coating modules, means for coating adhesion means on the shrink film, means for folding and pressurizing the shrink film on itself to form a sheath and packaging means in the form of individual reels or sleeves.

 The invention thus overcomes the drawbacks of the prior art, by allowing continuous, regular and without excess winding of a continuous sheath having an adhesion zone of minimal thickness and width greater than 1.5 mm.

 Tests have in fact shown that the resistance of an adhesion zone of width greater than 1.5 mm was of the same order or better than the resistance of the welded connections of the prior art while not having the drawbacks of these welded connections.

 Referring to Figure 2, a device according to the invention comprises printing means such as modules 3, 4 or 5 described with reference to Figure 1 and known to those skilled in the art, means for coating adhesion means, folding means and means for pressurizing the adhesion zones corresponding to the closure of the continuous sheath produced from the shrink film.

In the example shown, a shrink film 2 circulating in the direction of arrow L is driven by a drive roller 20, so as to pass between a coating roller 21 and a counter roller 22 for applying the film 2 on the roller 21. The roller 21 has a hollow machining corresponding to the deposition of a predetermined form of adhesion means A on the shrink film 2, for example a rectangular deposition of adhesion means
A, of width greater than 1.5 mm.

 As adhesion means A, use is preferably made of an adhesion means comprising a solvent which carries out a surface attack on the shrink film: a surface pickling similar to real chemical machining of the layer of shrink film is thus carried out, which produces after compression a real chemical weld in the corresponding adhesion zone.

 By way of adhesion, one can also use a glue or a pressure-sensitive coating, preferably an adhesive or a coating easily soluble in organic solvents such as for example from the group comprising esters, ketones, alcohols or chlorinated solvents, in particular compositions based on polymers or vinyl, polyurethane or polyester copolymers.

 Tests have in fact shown that maintaining the retractable strip 2 in tension during the folding and compression of the folded strip 2 to form a continuous sheath 10 makes it possible to obtain a folded sheath 10 of substantially constant thickness capable of being wound regularly or adapted to be sliced without burrs in individual packaging sleeves or sleeves.

In the example shown, the strip 2 carrying transverse rectangular coatings of adhesive product
A is then driven by passing over the rollers 23 to 25, then receives coatings of adhesive product B applied by brushes 26 and 27 connected to one or more containers 28 for supplying the brushes 26 and 27 by means of pipes or suitable pumping means.

 The retractable strip 2 thus carries in the vertical direction of the descent on the one hand the rectangles coated with adhesive product A and at least two substantially parallel surface areas of width corresponding to the width of the brushes 26 or 27 or equivalent application means. The strip maintained in tension by a lower tensioning roller 29 is regularly driven through a former comprising several rollers, for example three rollers 30, 31, 32, the axes of which are arranged at an angle with each other, so as to fold down first of all the edge of the strip 2 carrying the rectangles for coating adhesive product A on the strip 2, then then fold down the other panel carrying the areas for coating adhesive product B, so that the adhesive product A is located between the adhesion zones corresponding to product B.

 Of course, product A and product B could be of different composition, or of similar composition, the main thing being that the adhesion zone corresponding to these products A or B has, after compression, a thickness of less than fifty micrometers and a width greater than 1.5 mm.

The three roller shaper 30, 31, 32 also includes smoothing means 33 marking the folds of the edges before the sheath 10 is thus smoothed between two pressing rollers 34 and 35. At the exit of pressing effected by the rollers 34 and 35, the sheath 10 is driven by drive rollers shown diagrammatically by 36 to cutting means of the guillotine type, shown diagrammatically by 37. This gives individual sleeves comprising two adhesion zones of product B and a transverse adhesion zone corresponding to product A. According to the invention, the thickness of the longitudinal adhesion zones of product
B is less than fifty micrometers and the width of each longitudinal adhesion zone is greater than 1.5 mm.

 With reference to FIGS. 2 and 3, the successive steps of folding up a shrink film comprising on one side a coating of adhesive product A and on the other side a coating of two longitudinal parallel strips of adhesive product B are carried out the following way.

The coating of adhesive product from the passage of the strip in contact with the roller 21 comprising at least one hollow machining of suitable shape. The strip then passes successively over the rollers 23, 24 and 25 before descending in the direction of the arrow D. The strip descending in the direction of the arrow D in FIG. 2 is substantially vertical and under tension before passing under the roller tensioner 29. At the exit from the tensioning roller 29, the strip 2 is folded over the edges towards the middle of the strip 2 of shrink film until it forms a U-shaped contour before the first edge folds back the area of coating of adhesive product A, then a folding down of the other edge carrying on the front the two parallel strips of adhesive product B on this area. This gives a continuous sheath 10 comprising a compartmentalization into a main tubular sheath and a series of limited compartments laterally by two longitudinal adhesion zones B and interrupted transversely at periodic intervals by the adhesion zone corresponding to product A.

 After slicing, individual sleeves 38 are thus obtained having a main sheath 39 and a secondary pocket 40 closed by the adhesion zone corresponding to product A.

 Referring to Figure 4, a first embodiment of sleeves or packaging sleeves according to the invention is formed from a shrink film folded over on itself and closed on itself by adhesion or by gluing to constitute a main sleeve 41 having two folds marked on the edges 42 and 43 and an adhesion zone 44 having a surface thickness less than fifty micrometers and a width greater than 1.5 mm. The adhesion zone is shown in gray, for clarity of the drawing; however, the adhesion means are preferably chosen to be transparent after adhesion of the two edges of shrink film.

 As shrink film facilitating the implementation of the invention, there may be mentioned low density polyethylenes, medium density polyethylene, high density polyethylene, polyvinyl chloride, polypropylene, polyester, polystyrene or other thermoplastic materials equivalents capable of being stretched so as to provide heat shrinkage after heating of the sleeve surrounding the product to be protected or decorated.

 With reference to FIG. 5, a second embodiment of the invention comprises two compartments 45 and 46 obtained by folding down a free end 47 of the heat-shrinkable film coated with adhesive product, and by folding down the other free end 48 of the heat-shrinkable film on the part of the heat-shrinkable film already folded and comprising an adhesion zone of width greater than 1.5 mm. After slicing, sleeves or packaging sleeves are produced with two compartments able to receive objects of different size or shape and to fix them securely to each other after heat shrinking.

 With reference to FIG. 6, a third embodiment of the sleeve or packaging sleeve according to the invention similar to the embodiment described with reference to FIG. 5 is produced in a manner analogous to the method described with reference to FIG. 1. In this embodiment, the packaging sleeve comprises a main compartment 49 and a secondary compartment 50 which may, for example, contain an advertising label. In this case, it is advantageous to provide incisions 51 formed on one edge of the film by a roller provided with suitable pins, so as to constitute a dotted precut allowing access to the aforementioned label without damaging the packaging and in particular without breaking the inviolability of the compartment defined by the main sheath 49.

With reference to FIG. 7, a fourth embodiment of the invention, the manufacturing process of which has been described with reference to FIGS. 2 and 3 comprises two longitudinal grip zones B and a grip area
A transverse. Due to the method of manufacturing the sleeve, the transverse zones A delimit pockets 52 which are sealed from the outside and a main sheath 53 which extends continuously over the entire length of the sheath formed by implementing a method according to the invention.

 To use the plurality of pockets 54 of a sheath wound on a reel, it is seen that it suffices to cut the sheath at regular intervals into individual sleeves, providing that the slicing lines correspond to the inside of a pocket 52, for example at positions such as those shown in dotted lines and identified by the reference 54 in FIG. 8.

 With reference to FIG. 9, a fifth embodiment of the invention comprises two longitudinal grip areas 55 and 56, a transverse grip area 57 and two grip areas 58 and 59 extending transversely and longitudinally. These curvilinear adhesion zones 58 and 59 are also obtained by coating an adhesive product by means of a roller having suitable machining.

 In addition, pre-cut lines substantially parallel to the adhesion zones 58 and 59 are provided. The pre-cut lines 60 and 61 thus make it possible to extract two lateral surfaces 62 and 63 when cutting an individual sleeve from a continuous sheath.

 Above the transverse area 57, one can provide for example in the case of a label, dotted incisions 64 allowing the extraction of an advertising object or a reduction coupon.

 Advantageously, generally in all cases where the embodiments have adhesion zones extending transversely such as A in FIGS. 7 and 8 or 57, 58 and 59 in FIG. 9, provision is made to leave free space for the end of these areas extending transversely. The free space thus created allows the expulsion of air during the shrinkage of the packaging sleeve or sheath around the product to be packaged and thus avoids the formation of unwanted folds which could deform the printed decorations or damage the contents. of a pocket.

 The sleeve of FIG. 9 is particularly suitable for the packaging of a product of the bottle, flask presenting a neck or similar container: the upper part delimited by the adhesion zones 59 and 58 makes it possible after elimination of unnecessary surfaces 62 and 63 to have a substantially constant rate of retraction from top to bottom of the bottle, neck bottle or other similar container, thus ensuring both the protection, the decoration and the inviolability of the bottle, of the neck bottle or the packed container.

 Referring to Figure 10, a sixth embodiment of the invention similar to that of Figure 9 allows the packaging of pairs of flasks, bottles or other containers having a neck. In this example, the two-compartment packaging sleeve or sheath has a central zone 65 allowing the relative articulation of a packaging containing its bottle with respect to the other packaging containing its bottle.

 With reference to FIG. 11, a seventh embodiment similar to that of FIGS. 9 and 10 is shown implemented on four packaged bottles, so as to allow a grouped presentation of samples. The necked bottles thus wrapped are made inviolable by the cooperation of the upper part of each of the four compartments of the sleeve.

This inviolability and protection function thus makes it possible to observe that products have not been handled or polluted by untimely opening of the bottles.

 With reference to FIG. 12, an eighth embodiment of the invention is represented in the form of a continuous sheath comprising three adjacent tubular sheaths comprising precut lines 66 to 71 making it possible to obtain pockets or lateral sleeves of height lower than that of the main central sleeve or sleeve.

 Alternatively, by forming pre-cut lines in the middle part, it would be possible to obtain a central sleeve of height less than that of one or the other or of the two lateral sleeves.

 With reference to FIG. 13, a ninth embodiment of the invention is shown in the form of a continuous sheath comprising in its middle part a curvilinear incision 72 limited by two attachment points 73 and 74.

After slicing along line 75 in broken lines, sleeves are obtained, the edge of which is in a way "peeled" so as to be perfectly adapted to the end conformation of a product or container to be packaged.

 This embodiment has the advantage of providing an inviolable packaging and provides, after rupture of the packaging, a clear separation of the packaging into two parts without tearing of an intermediate part. This provision is particularly useful for packaging that can be handled or opened by children, in order to avoid accidental ingestion of strips of thermoplastic film.

 The invention allows in this case the automatic and continuous production of sleeves, the ends of which may have any shape and the separation of which is effected without tearing and without waste or part external to the packaging.

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

Claims (20)

 1. A method of printing and manufacturing sleeves or packaging sleeves, in which a reel (1) of thermoplastic film is unwound to unwind a continuous strip (2) and entrain it in successive printing sections (3 , 4) or decoration so as to print or decorate said continuous strip (2), characterized in that the continuous strip (2) is coated by spreading on the strip (2) an adhesion means, the strip is folded down (2) coated on itself while keeping it under tension, so as to form a continuous sheath (10) which is extracted while keeping it under tension.  2. Method according to claim 1 characterized in that the continuous strip is coated (2) after leaving the last printing or decoration module (3, 4).  3. Method according to claim 1 or claim 2, characterized in that the area of adhesion is compressed corresponding to the folding and closing of the continuous strip (2) on itself.  4. Method according to one of claims 1 to 3, characterized in that the continuous sheath (10) formed is extracted by winding it in the form of a coil (12).  5. Method according to one of claims 1 to 3, characterized in that the continuous sheath (10) formed is advanced so as to deliver it by slicing into sleeves or unitary packaging sleeves.  6. Method according to one of claims 1 to 3, characterized in that spreading the adhesion means on the continuous strip (2) using a spreading member (8).  7. Method according to one of claims 1 to 3, characterized in that spreads the adhesion means on the continuous strip (2) using a roller (21) comprising a hollow machining corresponding to deposit of a predetermined shape on the continuous strip (2).  8.- Device for printing and manufacturing sleeves for packaging sleeves, of the type comprising means for unwinding a reel (1) for unwinding a continuous strip (2) of shrink film, means (3, 4 ) continuously printing or decorating said strip (2), characterized in that the device further comprises coating means (8) of adhesion means, and folding-down means (30-32) of said strip (2) to form a continuous sheath (10).  9. Device according to claim 8, characterized in that the device comprises smoothing means (33).  10. Device according to claim 8 or claim 9, characterized in that the device comprises pressurizing means (34, 35).  11. Device according to any one of claims 8 to 10, characterized in that the device comprises cutting means (37).  12. Device according to claim 8, characterized in that the folding means comprise a shaper with several rollers (30, 31, 32).  13. Sleeve or packaging sheath, formed from a shrink film folded over on itself and closed on itself by adhesion or by gluing to constitute at least one main sheath, characterized in that the adhesion zone (44, A, B) corresponding has a surface thickness less than fifty micrometers and width greater than a millimeter and a half.  14. Sleeve or sheath U e1i'ballage according to claim 13, characterized in that the adhesion means comprises a solvent carrying out a surface attack of the shrink film.  15. Sleeve or packaging sleeve according to claim 13 or claim 14, characterized in that the adhesion means comprises an adhesive or a pressure-sensitive coating.  16. Sleeve or packaging sleeve according to any one of the preceding claims, characterized in that the sleeve comprises several compartments (45, 46) and several adhesion zones.  17. Sleeve or packaging sleeve according to any one of the preceding claims, characterized in that the sleeve has at least one incision (51, 72).  18. Sleeve or packaging sleeve according to any one of the preceding claims, characterized in that the sleeve comprises at least one transverse adhesion zone (A).  19. Sleeve or packaging sleeve according to any one of the preceding claims, characterized in that the sleeve comprises at least one pocket (52).  20. Sleeve or packaging sleeve according to any one of the preceding claims, characterized in that the sleeve comprises at least one adhesion zone (58, 59) extending transversely and longitudinally.