WO1993008011A1

WO1993008011A1 - Method of manufacturing a labelling sleeve, and sleeve thereby obtained

Info

Publication number: WO1993008011A1
Application number: PCT/FR1992/000965
Authority: WO
Inventors: Jean-Pierre Metayer
Original assignee: A.H.N. Andre Huault Et Neoplast S.A.
Priority date: 1991-10-14
Filing date: 1992-10-14
Publication date: 1993-04-29
Also published as: FR2682320B1; FR2682320A1; EP0610369A1

Abstract

In a method of manufacturing a labelling sleeve by means of a cut and weld operation on a thermal plastic sheet, the weld line (2) is positioned inside the sleeve by reversing the latter, or the weld is made internally.

Description

METHOD FOR MANUFACTURING A LABELING SLEEVE AND SLEEVE OBTAINED ACCORDING TO THIS METHOD.

The subject of the present invention is a method of manufacturing a labeling and decoration sleeve intended, in particular, but not exclusively, to be placed stretched over a container, its internal perimeter being less than the perimeter of the container to be decorated. '' from 1 to 6%.

Such sleeves are well known and, increasingly, widely used. Generally made from a bi-oriented polyethylene film, they are applied intimately to the side wall of the container by stretching, after

10 printing and forming of the sleeve. Such sleeves have notable advantages with regard in particular to the quality of the printing, which is carried out flat, allowing various multicolored decorations and the use of a maximum surface to transfer to this, -. labels the information consumers need.

The stretched labeling eliminates the need to use an adhesive which always poses significant problems when recycling containers made of _2Q plastic materials.

Before printing the film flat, it is subjected to a treatment by CORONA effect (oxidation of the surface by an electric arc) allowing the adhesion of the inks on the material.

After printing, the printed film is folded back on itself, its longitudinal edges being welded. However, the printed parts cannot be welded, the inks 0 constituting an insulator for welding. It is therefore necessary to provide during printing a reserve determining the welding area. Two welding methods are currently used. The first process, known as "overlap welding", consists in folding the longitudinal edges of the sheet over one another and joining them together by thermo-compression. This process is however practically abandoned because the welding cannot be carried out edge to edge and it always presents a projecting projection coming from the non-thermo-welded part which harms the esthetics and gives during the grip of the container an unpleasant impression. .

The second process known as "welding cutter" does not have the same drawback since finally the two edges of the sheet are in the extension of one another. However, as indicated above, it is necessary to create a printing reserve on either side of the weld line. This reserve interrupts the decor for 6 to 10 mm and over the entire height of the sleeve. The longitudinal weld cutter also leaves a projecting edge whose height is approximately 0.5 to 1 mm and whose contact is unpleasant.

Furthermore, the resistance of a weld made on two faces treated with the CORONA effect is less reliable and less resistant to the phenomena of "stress crack ing" or cracking due to tension.

JP-B-457 879 (FUJIO) discloses a method for manufacturing overcapping capsules for bottles obtained by welding from a film of heat-shrinkable resin, the welding being carried out inside the capsule and the welded edges being edges opposite the printed surface.

GB-A-2130 169 describes a process for manufacturing sleeves from two opaque films, the printing being carried out on the external face. However, these documents do not relate to the manufacture of transparent sleeves printed on their entire surface.

The object of the present invention is to overcome these drawbacks and to eliminate the printing reserve and the outer welding edge.

According to the present invention, the method of manufacturing a labeling sleeve by thermal welding cutter or bonding of a transparent pre-printed thermoplastic sheet and folded back on itself, the connecting line being disposed inside the sleeve is characterized in that it consists in making the connection outside the sleeve and then turning it over on itself before it is placed on the container to be labeled.

Thus, it is possible to delete the print reserve and make the weld edge invisible. The decoration can extend over the 360 ° of the label.

In a first embodiment, the welding is carried out outside the sleeve and the latter is turned over before it is placed on the container.

In a second embodiment, the welding is done directly during the shaping of the sheath, the welding equipment being inserted between the two strips intended to form the sheath.

The presence of the weld line inside the sleeve eliminates the aforementioned drawbacks and allows the decor of stackable and unstackable conical shapes. In fact, there is no longer any welding edge which is capable of blocking the automatic destacking machines for thermoformed or injected containers, which use a rotation of the receptacles coated with sleeves.

Other characteristics and advantages of the invention will emerge during the description which follows. particular embodiments given by way of nonlimiting examples with regard to the figures which represent:

- Figure 1 a coil containing different sleeves one behind the other and having an outer weld;

- Figures 2 and 3 diagrams of flipping a mancho;

- Figure 4 a diagram of forming a sleeve according to the second embodiment;

- Figure 5 a section at the weld.

In Figure 1, we see that on the coil 1 is disposed a flattened sheath 1 having on one of its edges an outer weld line 2 which can be performed in conventional manner. The sheath 1 has transverse lines of least resistance or pre-cuts 3 spaced at regular pitch, the length of sheath between two lines 3 constituting a sleeve 4 which can be easily detached from the sheath 1. In this case, when the printing is carried out on a transparent synthetic material, it is carried out on the outside of the sheet, the welding thus being external. A sleeve 4 is then detached from the sheath 1 and placed on turning tongs 5 (FIG. 2) which in the example shown are three in number. By reversing the clamps and introducing a jet of compressed air inside the sleeve 4, the arrangement shown in FIG. 3 is obtained. The impression 6 and the solder 2 are then found inside the sleeve 4 which can be placed under a tension of 1 to 6% on the side wall of the container of any shape, the flexibility of the sleeve allowing its adaptation to any shape thereof.

A container to be decorated is then introduced inside the sleeve.

However, this process requires an adaptation of all existing automatic laying machines.

It is possible to proceed according to another embodiment in which the welding is carried out inside the sheath with evacuation of the scrap from the open side of the sheath.

In FIG. 4, the sheet 10, folded around an edge 11 to define two strips 12, 13 is driven along the arrow F and first passes through a guide or shaping device 14 which folds the edges of the two strips so to form two flanges 15 and 16 folded back inside the strips. The CORONA treatment is only carried out on the side bearing the print. The surfaces of the flanges coming into contact with each other are not treated and are therefore perfectly weldable. The flanges 15 and 16, face to face are then applied to a table 17 which is located between the two strips and which comprises a heating element 18 connected to an energy supply source 19. The passage over the heating element causes, as known per se the weld 2 of the two edges and the formation of a drop 20. The weld 2 is an internal weld to the sheath 1. On the other hand, the drop 20 is evacuated between the strips 12 and 13 on the side opposite to the edge 11 in the direction opposite to the direction of progression of the sheet 10 (arrow Fl). It can fall or be dragged by a roller. Sheath 1, internally welded 2 pass then, for example, in a pre-cutting stage 21 which forms in the sheath 1 easily detachable sleeves.

Printing on the entire surface of the strips (except the edges) can be carried out on the inside of the transparent polyethylene sheet. The advantage of interior printing is that it preserves the decor from external aggressions such as the rays since it is located between the polyethylene and the object to be decorated. The folding of the edges ensures that the welding is carried out on untreated CORONA surfaces. In addition, in the case of stackable containers, the printing ink is never in contact with the internal surface of the lower container intended to be in contact with food products if necessary.

After tearing off a sleeve, it is stretched over a frame which descends on the container and is released around said container.

It goes without saying that many variants can be introduced, in particular by substitution of technically equivalent means such as bonding for example without departing from the scope of the invention. In the case of formation by gluing, the connecting line consists of a line of glue.

Claims

1. Method of manufacturing a labeling sleeve by thermal welding cutter or bonding of a transparent pre-printed thermoplastic sheet and folded back on itself, the connecting line being disposed inside the sleeve characterized in that it consists in making the connection outside the sleeve and then turning it over on itself before placing it on the container to be labeled.

2. Method according to claim 1, characterized in that the welding line (2) is produced inside two strips (12, 13) constituting by welding the sheath (1), said welding being carried out on two flanges ( 15, 16) folded over each of the strips (12, 13).

3. Method according to claim 2, characterized in that the drop (20) is discharged from the rear, between the strips (12, 13) in the direction opposite to the direction of progression of the sheet (10).

4. Method according to one of claims 2 or 3, characterized in that the faces of the flanges (15, 16) coming into contact with each other are faces opposite to the face of the sheet carrying the print .

5. Labeling sleeve obtained by the method according to any one of the preceding claims.