WO2005014424A1

WO2005014424A1 - Packaging film

Info

Publication number: WO2005014424A1
Application number: PCT/EP2004/008244
Authority: WO
Inventors: Edouard Baron
Original assignee: Mars, Incorporated
Priority date: 2003-07-24
Filing date: 2004-07-23
Publication date: 2005-02-17
Also published as: EP1651534A1; FR2857939B1; FR2857939A1

Abstract

A packaging film (10) has an edge (11) that includes regularly spaced notches (15). Application to a batch of goods (30) packaged by bundling with a plastic film surrounding the said batch. The edge of the film defines a lune (33) on one side of the batch and the lune has notches (15). The notches (15) constitute tear initiators in the film (10) so as to make unpackaging easier.

Description

PACKAGING FILM

The present invention relates to packaging film, such as heat-shrink film or stretch film, for surrounding goods to be packaged. Packaging films are widely used in many industries, and in particular in the consumable industry. Goods for sale on the market are often transported in batches that group together a number of sale units of a product to be sold. Packaging is used to protect these units, such as cartons, tins or jars for example, and to keep them together. Likewise, bottles are often sold in packs containing in general six bottles held together by a packaging film. Such packaging in batches is known by the term "bundling". Bundling consists in surrounding a batch of goods with a plastic heat-shrink or stretch film. The particular feature of this packaging is that the sides of the batch are generally not welded and they leave the goods visible. The unwelded plastic located along the sides of the batches is generally called a "lune". A lune is defined as a non-convex plane figure bounded by two circular arcs having the same ends. When the bundling is carried out with a plastic heat-shrink film, the lune is often blistered. A heat-shrink film has the characteristic of shrinking under the effect of heat and therefore of moulding the object that it surrounds. The shrinking may take place in one direction or in two perpendicular directions, depending on the composition of the film, by a rise in temperature. A stretch film has cold elasticity properties that allow it to be stretched around the object to be packaged without a rise in temperature. The film is held in place by welding. A plastic heat-shrink film may be obtained from a polyolefin, such as high-density polyethylene, low-density polyethylene or polypropylene, or from polyvinyl chloride (PVC). A plastic stretch film may be obtained from a linear polyethylene or a polyvinyl chloride (PVC). Such plastic packaging films are strong, easy to apply and able to suit any type of object to be packaged, whatever its shape or its dimensions. However, these packaging films are not easy to tear, and to unpackage goods surrounded with such a film often requires the use of a tool, such as a cutter for example. To make it easier to tear the film for manual unpackaging of the goods, several techniques have been proposed. A first solution consists in adding additives to the chemical composition of the film so as to create an orientation that weakens the film in one direction. However, this solution increases the cost of manufacture of the film. An orientation of the film may also be obtained by microperforations that impose a linearity on the tearing of the film. With these solutions, the propagation of the tear is facilitated by the linearity of the film, but it remains difficult to initiate the tear. Another solution consists in weakening the film in certain areas corresponding to gripping areas, for example between four bottle tops. The weakening may be achieved by niicroperforations localized in certain areas of the film. However, this solution complicates the manufacture of the packaging film and requires registration of the film with respect to the product to be packaged, thereby complicating the industrial packaging process by requiring the use of machines for packaging with registration. In addition, the tear is initiated with one's fingers and not with one's hand, and the opening of the batch in general remains partial. Another known solution for making it easy to unpackage goods packaged with a film consists in adding a tear tape to the packaging film. This solution - comfortable for the user - adds a significant cost to the film, firstly because of the addition of an element and secondly as it requires the use of a packaging film with registration in order to position the tape correctly. There is therefore a need to simplify the tearing of packaging films. The invention consequently proposes a packaging film having an edge that includes notches, said notches being distributed along said edge. According to one feature, the film includes notches on each edge. According to another feature, two consecutive notches on an edge are spaced apart from 5 to 15 cm. According to another feature, the notches have a depth of 5 to 10 mm. According to another feature, the notches are perpendicular to the edge of the film. Depending on the embodiments, the film is of the heat-shrink type or of the stretch type. The invention also relates to a batch of goods packaged by bundling with a plastic film surrounding the said batch, one edge of the film defining a lune on one side of the batch, the lune having notches. According to one feature, two consecutive notches of a lune are spaced apart by 5 to 15 cm. Depending on the applications, the batch of goods comprises a pack of bottles or a set of cans. The invention furthermore relates to a method of packaging a batch of goods with a plastic film, comprising the steps of: - producing notches distributed along an edge of the film; and bundling the batch of goods with the film. According to one method of implementation, the bundling step includes a step of heat- shrinking the film. According to one method of implementation, the film is a stretch-type film and the bundling step includes a welding step. According to one method of implementation, the film is unwound for the bundling and the notches are produced continuously on a film turn roll. According to another method of implementation, the film is unwound for the bundling and the notches are produced in series along a portion of the film placed flat in a cutting zone. According to one method of implementation, the notches are produced on each edge of the film. According to one feature, the notches are produced with a spacing of 5 to 15 cm between two consecutive notches. According to one feature, the notches are produced with a depth of 5 to 10 mm. According to one feature, the notches are produced perpendicular to the edge of the film. Other features and advantages of the invention will become apparent on reading the following detailed description of embodiments and methods of implementation of the invention, given solely by way of example and with reference to the drawings that show. Figure 1, a diagram of the packaging film according to the invention; and Figure 2, a batch of goods packaged with a film according to the invention. According to the invention, a packaged film is proposed that has notches on at least one edge. These notches constitute tear initiators that facilitate the initial tearing. The notches are deep enough to initiate the tearing movement and are distributed along the film so that the package can be taken hold of with one's whole hand in order to tear it. The packaging film proposed by the invention may be used for bundling batches of goods with a conventional bundling machine or bundler, without registration. Thus, an easy- tear packaging film may be used for bundling without any significant increase in cost. According to the invention, a batch of packaged goods is therefore obtained by bundling with a film having notches in its lunes. These notches are placed so as to allow one edge of the packaging to be gripped with one's whole hand between two of the said notches, thereby allowing easy tearing on either side of the point gripped. In Figure 1, a plastic film 10 is being unwound. This film 10 may be of the heat-shrink or stretch type depending on the applications. It also has a width suited to the size of the batch of goods to be packaged. A longitudinal direction x of the film constituting the film unwinding direction, and a transverse direction y of the film 10, constituting the film cutting direction, are defined. Such a film 10 is designed to be placed in a packaging machine called a bundler. Such a machine makes it possible to surround a batch of goods with the film 10, to cut the film from edge to edge and to fasten the film over the batch. If the film is made of heat-shrinkable plastic, the bundler includes, or is connected to, heat treatment means such as an oven. The plastic is then moulded around the batch after heat-shrinking. If the film is a stretch plastic, the bundler includes, or is connected to, welding means. The stretch film is then moulded around the batch after each cut end has been welded. According to the invention, the film 10 has notches 15 along an edge 11 and optionally along each edge 11, 11'. These notches 15, 15' are designed to constitute packaging tear initiators when the film 10 has been used for bundling a batch of goods. The notches 15 are distributed along the edge 11, that is to say the notches 15 are repeated along the edge of the film. The spacing between two consecutive notches may depend on the applications, on the type of batch to be packaged and on the bundling process used. The notches 15 distribution along an edge 11 of the film can be regular, that is to say the notches distribution has a regular pattern repeating with spacing between two consecutive notches that may be constant or variable. The notches distribution can be linear, that is to say the spacing between notches varies linearly. The notches distribution can also be random, with a random spacing between the notches. Advantageously, this spacing must be wide enough to allow one's hand to be positioned between two notches, but not necessarily consecutive notches, and small enough for the gripping to easily tear the notch and extend the tearing of the packaging film transversely. For example, a spacing of 5 to 15 cm between two consecutive notches fulfils these conditions. The detail A shown in Figure 1 illustrates a notch 15 in one edge of the film 10. Such a notch has a notch depth L of 5 to 10 mm and an almost zero width e. The notches may be produced perpendicular to the edge 11, but they may also be oblique without losing their film tear initiation function. According to the invention, a method of packaging a batch of products is proposed.

Such a method comprises a step of producing the notches along one edge of the packaging film and a step of bundling the batch of goods with such a film. The notches 15, 15' may be produced by any suitable means. For example, as illustrated in Figure 1, the plastic film 10 is unwound longitudinally (x direction) and passes over a turn roll 20 whose spindle is oriented in the transverse direction (y) of the film. A cutting roll 25 is placed opposite the turn roll 20 and rotates in the opposite direction from the direction of rotation of the turn roll. The film 10 is thus pinched between the two rolls 20 and 25, while being unwound. The detail B in Figure 1 shows that the cutting roll 25 has projecting blades 26 that notch the edge 11 of the film 10 in order to make notches 15. The size of the blades 26 is adapted according to the depth L of the notches to be produced. Other embodiments of the notches may be envisaged. Thus, for example, the notches may be produced in series over portions of film that are placed flat in a cutting zone. Figure 2 illustrates a batch of goods 30 packaged by the method according to the invention using the film 10 according to the invention. In the example shown in Figure 2, the batch 30 consists of two packaged cardboard boxes 31, 32, but it could just as well be a pack of bottles, or a batch of tins or jars for example. The batch of goods 31, 32 is packaged by bundling with a plastic film 10, the edges 11 of the film defining lunes 33 on the sides of the batch. In particular in the case of the use of a plastic heat-shrink film, the lunes 33 have blisters. In such a case, the initial tearing along the edges of the packaging 30 is very difficult. According to the invention, the notches 15 produced in the edge 11 of the film are transferred to a lune 33 of the packaged batch and allow tearing to be initiated from the lunes 33 in order to make unpacking easier. Specifically, when a user grips a lune 33 with his whole hand, there will be notches 15 on each side of his hand. His hand may possibly cover one notch 15, but there will nevertheless be, on either side of his hand, two notches sufficiently close to the edge of his hand. These notches 15 must make it possible, by a limited tearing force perpendicular to the plane of the film, to extend the tearing of the film 10 and allow easy unpackaging. Of course, the present invention is not limited to the embodiments and methods of implementation described by way of example with reference to the figures; in particular, the spacing between two consecutive notches or the depth of the notches may vary or be constant along one edge portion of the film. If the notches 15, 15' are produced on each edge 11, 11 ' of the film 10, the depth L of the notches and the spacing between the notches are not necessarily the same along each edge.

Claims

1. Packaging film (10) having an edge (11) that includes notches (15), said notches being distributed along said edge.

2. Packaging film according to Claim 1, having notches (15, 15') along each edge (11, 11')-

3. Packaging film according to Claim 1 or 2, wherein two consecutive notches (15) on an edge (11) are spaced apart by 5 to 15 cm.

4. Packaging film according to one of the preceding claims, wherein the notches (15) have a depth of 5 to 10 mm.

5. Packaging film according to one of the preceding claims, wherein the notches (15) are perpendicular to the edge (11) of the film (10).

6. Packaging film according to one of Claims 1 to 5, which is of the heat-shrink type.

7. Packaging film according to one of Claims 1 to 5, which is of the stretch type.

8. Batch of goods (30) packaged by bundling with a plastic film (10) surrounding the said batch, one edge (11) of the film defining a lune (33) on one side of the batch, the lune (33) having notches (15).

9. Batch of packaged goods according to Claim 8, wherein two consecutive notches (15) of a lune (33) are spaced apart by 5 to 15 cm.

10. Batch of packaged goods according to Claims 8 or 9, comprising a pack of bottles.

11. Batch of packaged goods according to Claims 8 or 9, comprising a set of cans.

12. Method of packaging a batch of goods (30) with a plastic film, comprising the steps of: - producing notches (15) distributed along an edge (11) of the film (10); and bundling the batch of goods with the film.

13. Method according to Claim 12, wherein the bundling step includes a step of heat- slirinking the film (10).

14. Method according to Claim 12, wherein the film (10) is a stretch-type film and in that the bundling step includes a welding step.

15. Method according to one of Claims 12 to 14, wherein the film is unwound for the bundling and the notches (15) are produced continuously on a film turn roll.

16. Method according to one of Claims 12 to 14, wherein the film is unwound for the bundling and the notches (15) are produced in series along a portion of the film placed flat in a cutting zone.

17. Method according to one of Claims 12 to 16, wherein the notches (15, 15') are produced along each edge (11, 11') of the film (10).

18. Method according to one of Claims 12 to 17, wherein the notches (15) are produced with a spacing of 5 to 15 cm between two consecutive notches.

19. Method according to one of Claims 12 to 18, wherein the notches (15) are produced with a depth of 5 to 10 mm.

20. Method according to one of Claims 12 to 19, wherein the notches (15) are produced perpendicular to the edge of the film.