EP0442111A2

EP0442111A2 - Process to package loose objects, particularly bottles, machine to carry out said process, and transportable packaging obtained with said process

Info

Publication number: EP0442111A2
Application number: EP90124724A
Authority: EP
Inventors: Franco Tacchini
Original assignee: Officina Meccanica Sestese SpA
Current assignee: Officina Meccanica Sestese SpA
Priority date: 1989-12-22
Filing date: 1990-12-19
Publication date: 1991-08-21
Also published as: EP0442111A3

Abstract

The invention concerns a method and a machine for packaging a group of six bottles (B) by means of two intersecting wrappings (1), (5) of plastic material, allowing to obtain a portable packing. The first wrapping (1) is applied on the vertical plane and is then gathered up at the top of the packing, so as to form a comfortable handle (6) allowing to grip the same; said vertical wrapping is formed in its upper part of a length of strong polyethylene strap, and in its lower part of a length of polypropylene or polyvinylchloride adhesive tape. The second wrapping (5) is applied on the horizontal plane and consists of a film of plastic stretching material, apt to tighten the first wrapping and block it into position. The invention also concerns the portable packing obtained with said method.

Description

The present invention concerns a method and a machine for packaging different objects, particularly bottles, allowing to obtain a packing meant for hand transport by the buyer. The invention also concerns the portable packing obtained with said method.
It is known that, for packaging bottles for retail sales, use has been made for several decades of returnable wooden or plastic boxes containing a dozen of bottles. Such a solution involves different drawbacks, as a high cost, the requirement of a service to return the empties (empty bottles as well as empty boxes), a great waste of space even when the box is empty, as well as a heavy weight when it is filled with bottles such as to make it difficult for most buyers to carry it by hand.
To replace the boxes, smaller packings have recently been proposed, comprising for example six one- or two-litre bottles arranged on two rows of three side-by-side bottles, held together by a film of thermoretractible plastic material. With this solution, packaging costs have been notably lowered, the need to return the empties has disappeared, and the weight of each packing has been reduced to an extent such as to make it hand transportable even for fairly long distances.
Nevertheless, these packings of thermoretractible plastic material are still not considered fully satisfactory, on one hand because of their cost and on the other hand due to actual transport difficulties. In fact, owing to its reduced weight, the packing could be easily carried with a single hand, but since it lacks adequate gripping means, it has to be forcedly carried using both hands, thereby depriving the buyer of that freedom of movement which is essential to allow him to easily do the shopping and carry the bags.
To overcome these drawbacks, it has recently been proposed to supply packings, equally consisting of a closed film of thermoretractible plastic material, but provided with a gripping handle formed of a plastic strip surrounding the packing itself. This solution has however the fundamental drawback of requiring additional packaging elements which, beyond their intrinsic cost, also involve an additional cost for their application. Furthermore, the plastic strip - due to its modest transversal dimensions - can easily "cut through" the packing and cause unpleasant and painful sensations to the hand carrying the same.
Still more recently, packings have been proposed which consist of two intersecting wrapping films of plastic stretching material, one of which - and precisely the wrapping extending in the vertical plane - is meant to form also a gripping handle. These packings are described for example in US-A-4,304,332 and in US-A-4,596,330, as well as in the Italian Patent Application No. 21.483 A/89 in the name of the same Applicant. Nevertheless, the packings described in all these patents still involve at least two drawbacks:

On one hand, the wrapping meant to form the handle, and thus extending on a vertical plane, involves considerable packaging problems: in fact, since said wrapping extends under the bottom of the bottles, these need to be kept lifted from their respective bearing surface while the wrapping is being applied thereon. To do so, one should thus first form the wrapping on a horizontal plane so as to tighten together the bottles into a single block; said block of bottles is then gripped on the side so as to be lifted and allow forming the second wrapping on the vertical plane.
On the other hand, when gripping the wrapping which forms the handle - consisting of a film of plastic stretching material - this latter tends to loosen during transport, under the weight of the bottles. Seen the nature of this plastic material, the longer the carrying distance the more the handle stretches out, and the more it stretches out the narrower it gets, thereby producing both an unpleasant cutting sensation on the hand carrying the same, and a loosening of the wrapping such as to cause its misplacement or even its slipping off from the block of bottles, with further transport difficulties.

The object of the present invention is to therefore propose a packing - of the heretofore mentioned type, formed of two intersecting wrappings, one extending on the horizontal plane and the other on the vertical plane, the vertical wrapping forming also gripping means for the packing, in the form of a handle - which is even more improved in respect of those described in the above indicated patents.
More precisely, a first object of the invention is to provide a packing of the aforecited type, wherein the vertical wrapping, forming the gripping handle, shows improvements both for what concerns the comfort for the hand carrying the packing and for what concerns its transport resistance.
A further object of the invention is to obtain a packing of the aforecited type, wherein the vertical wrapping holds more tightly and more reliably onto the group of bottles.
According to the invention, these results are achieved with a method for packaging a group of objects, particularly a group of bottles, essentially characterized in that,

to start with, the wrapping on the vertical plane is formed by feeding a first length of strap from the top over the group of objects and a second length of strap from the bottom under said objects, and by then joining together the leading and, respectively, the tail ends of the two strap lengths;
subsequently, a second wrapping is formed on the horizontal plane using a strap of plastic stretching film, which is wound into several turns over the first wrapping so as to tighten it and block it against the group of objects; and
said first strap length of the vertical wrapping is finally gathered up at the top so as to form a gripping handle.

It is thus possible, according to the invention, to select the material forming the first strap length, so that its characteristics may be particularly suited to form a gripping handle, while the material of the second strap length can be selected so as to have the best properties for adhering onto the block of objects.
More precisely, and according to a preferred embodiment of the invention, the first strap length will consist of a flexible plastic material with high tensile strength, such as a polyethylene film having a thickness of 60/70 µm.
Also according to a preferred embodiment of the invention, the second strap length will consist of a commercial type adhesive tape, of polyvinylchloride (PVC) or polypropylene, applied with its adhesive surface facing upward, so as to adhere to the bottom of the objects, and allow the leading and tail ends of the straps to be joined together by simple adhesion of the ends of the second strap length onto the ends of the first strap length.
Further characteristics and advantages of the packaging method, machine and packing according to the invention will anyhow be more evident from the following detailed description of some preferred embodiments thereof, given by way of example and illustrated on the accompanying drawings, in which:

Fig. 1 is a diagrammatic perspective view of a group of six bottles onto which a first wrapping has been applied, consisting of a film of flexible plastic material extending on the vertical plane and designed to form a gripping handle;
Figs. 2, 3 and 4 show diagrammatically how to form said first wrapping;
Fig. 5 is a view similar to fig. 1, showing how to apply the second wrapping consisting of the film of plastic stretching material;
Fig. 6 is a diagrammatic plan view, with some removed parts, showing the packing after the second wrapping has been completed;
Figs. 7, 8 and 9, show how to form the gripping handle with the first wrapping and how to carry the packing; and
Fig. 10 is a diagrammatic perspective view, showing in further detail the mechanical elements of a working station in which the first vertical wrapping is formed.

The packaging method according to the invention is first of all described with reference to figures 1 to 9, showing only a trace of the machine to carry out said method. The working station of said machine, in which the vertical wrapping is formed, is subsequently described in further detail with reference to figure 10.
It has to be pointed out that the packaging machine illustrated on the accompanying drawings and described hereinafter is designed for a packing of six bottles. It is however understood that the description of said machine is given by mere way of example and should in no way be interpreted as limiting the protection scope of the invention, which can instead be generally applied to any other type of packaging machine allowing to obtain a packing in the form of two intersecting wrappings consisting of a film of plastic material.
As shown in figure 1, a first wrapping extending on a vertical plane is formed on a group of objects to be packaged, particularly a group of six plastic bottles B positioned side-by-side in two rows of three; said wrapping is formed in two parts and, precisely, an upper strap 1 and a lower strap 2, joined together.
Figure 2 shows how the two straps 1 and 2 are fed, starting from two respective feed rolls 1a and 2a, to a packaging machine having a sliding surface in the form of rollers 3 and a closing and cutting tool 4.
At the start of the packaging operation, the two straps 1 and 2 are joined together by their ends, in U. This connection is obtained by glueing, thermowelding, or the like, as better specified hereinafter.
As it appears evident from the sequence of figures 2 and 3, the bottles B - moving forward on the surface 3 in the direction F - bear against the two joined straps 1 and 2 (fig. 2) and drag them forward (fig. 3) so as to allow forming a vertical wrapping, which initially covers the right side (in respect of the drawing) and the upper and lower sides of the group of bottles B.
When the bottles have reached a position (fig. 3) beyond the cutting tool 4, this latter is moved down - as shown in figure 4 - so as to cut the straps 1 and 2. While cutting, the tool 4 also provides to stick together, on one side, the ends 1′ and 2′, so as to complete the wrapping and close the packing and, on the other side, the ends 1˝ and 2˝, so as to allow the next packaging operation. In this way, a first wrapping of the group of bottles, extending on the vertical plane, has been completed as shown in figure 1. The operation of the cutting tool 4 is described in further detail with reference to figure 10.
The upper strap 1 of said first wrapping preferably consists of a film of flexible plastic material, as for instance polyethylene, having a thickness of 60/70 µm.
According to a preferred embodiment of the invention, the lower strap 2 is instead an adhesive tape of commercial type, for example a polyvinylchloride (PVC) or polypropylene tape with one of the surfaces having a layer of adhesive substance. The use of this strap provides a double advantage:

on one hand, it facilitates joining the two ends of the straps 1 and 2 when closing the vertical wrapping, so that the tool 4 must simply cut and stick the adhesive tape;
on the other hand, the strap 2 adheres also to the bottom of the objects being packaged - particularly the bottom of the bottles B - thereby helping to keep said objects firmly positioned in the packing and, at the same time, guarantee the fastening of the vertical wrapping.

According to a different embodiment of the invention, it is of course possible for the lower strap 2 to be equally formed of a polyethylene film - like the upper strap - and to be anchored onto the strap 1 by glueing or thermowelding. In this last case, the tool 4 will obviously be provided with thermowelding means.
The packaging method then provides for a further step wherein a second wrapping is formed, using a strap which extends on the horizontal plane, as shown in figure 5. Said second wrapping 5 consists of a film of plastic stretching material - as PVC, EVA (ethylvinylacetate), LPDE (low density polyethylene) and, above all, LLPDE (low density linear polyethylene) - wound into several turns over the first wrapping 1-2. This second wrapping is applied under slight tension, so as to positively block in position both the packed objects and the vertical wrapping.
Figure 6 shows how the second wrapping 5 keeps the first wrapping 1-2 strongly tightened against the lateral surface of the bottles, and thus forms an integrating part of the packing. Practical tests have shown that this tightening action is sufficient to keep fastened the strap 1 of the first wrapping even if the strap 2, and thus the respective anchorage, should be missing.
In the final step of the packaging method according to the invention - shown in figures 7 to 9 - a gripping handle 6 is formed by gathering up the strap 1 at the top of the vertical wrapping.
Referring now to figure 10 - which, as said, shows in further detail the working station in which the vertical wrapping is formed - it can be seen that the bottles B1, sent from a bottling line and advancing in a vertical position onto a sliding surface - for instance the already mentioned rollers 3, or a horizontal belt conveyor (not shown) - are divided into groups of six, each group being stopped in succession in the different working stations of the packaging machine, and precisely the stations supporting the groups of bottles B1A, B1B, B1C and respectively B1D (of which only station B1B is shown to form the vertical wrapping).
In the working station B1B, as shown in figure 10, the lower strap 2 - preferably, as said, an adhesive tape - is unwound from a feed roll 2a, by way of a motored unwinding roller 9, and is fed onto the horizontal sliding plane of the bottles with its adhesive surface facing upward, so as to come into contact with the bottom of the bottles B1B.
The upper strap 1 - preferably, as said, a film of strong and flexible plastic material, of the PVC or polypropylene type - is unwound from a feed roll 1a and moves first of all across a set of driving rollers 10, meant to develop a length of film so as to facilitate unwinding, and subsequently across a cutting and applying head 11, movably mounted along vertical guides (not shown).
The head 11 is formed of a stiff body, ending at the bottom with an oblique surface 11a. A cutter 12, to cut the strap, is fixed on the side opposite to the surface 11a. A sliding block 13 is moreover positioned against the cutter 12 for protection thereof, said block being mounted vertically slidable - against the action of spring means 14 - between a lowered position protecting the cutter 12 (shown in figure 10) and a raised position in which the cutter is free to cut the straps 1 and 2 (as better described hereinafter). The sliding block 13 has in turn an oblique surface 13a, opposite to the surface 11a and forming therewith a kind of wedge.
A counterhead unit is mounted beneath the horizontal sliding plane of the bottles, said unit consisting of a U clip 17 mounted on a support 18 moving vertically under the action of a piston 19. The clip 17 is formed of a flat spring, the arms of which tend to open wide apart due to elasticity and, in a rest position, they bear onto a pair of fixedly mounted guide bars 20.
When the vertical wrapping is formed in the working station B1B, the head 11 is moved down from the rest position shown in figure 10, in the direction of the arrow F3, carrying with it the strap 1 down to the position indicated by the dash-and-dot line 1′. As can be seen from the drawing, the strap 1 bends at the bottom taking up a wedge profile, which corresponds to its bearing onto the oblique surfaces 11a of the head 11 and 13a of the sliding block 13.
At the end of the downstroke of the head 11, the sliding block 13 is raised, leaving the cutter 12 free to cut the strap 1. The two strap ends, thus cut, move away from the surfaces 11a and 13a, and are applied - for example by an air jet blown by nozzles (not shown) -against the side of the bottles of the group B1B and, respectively, against a bearing plate 11′ fixed to the body of the head 11 (said bearing plate 11′ being at this stage adherent to the side of the bottles of the group B1A).
At the same time, the support 18 is moved upward together with the clip 17, the arms of which press first of all the strap 2 against the cutter 12, up to causing its cutting. As the clip 17 moves up even further, its arms, being released from the bars 20, then open elastically wide apart and press the cut ends of the strap 2 against the side of the bottles B1B and, respectively, against the plate 11′, that is, over the ends of the strap 1 (which were already bearing on said surfaces) onto which they stick.
This application of the adhesive surface of the strap 2 onto the strap 1 produces a permanent connection between the two straps: this allows to close the vertical wrapping on the side of the group of bottles B1B, and to form the initial junction for a new wrapping - like the U junction on the group of bottles B1B - on the side of the group of bottles B1A. The bottles can thus be moved forward towards the third working station, taking up the position of the group of bottles B1C, while their place is taken by the group of bottles B1A positioned further upstream, which, in its forward motion, draws the required length of reciprocally joined straps 1 and 2, as described with reference to figure 3.
As already briefly mentioned, the main advantages of the packaging method according to the invention are:

on one hand the fact that, by forming the vertical wrapping with two distinct and separately fed strap lengths, it is possible to select the material for each strap independently and thus with the properties most suited for the functions of each strap length;
in particular, the material selected for the upper strap length will have to be strong, so as not to loosen during transport, and smooth, so as to provide the necessary comfort for the hand, while the material selected for the lower strap length will have to be strong and, at the same time, apt to adhere to the bottom of the bottles;
on the other hand the fact that, this packaging method allows to apply the vertical wrapping in the first place, without having to lift the group of bottles (which is practically impossible, according to prior art, seen that there is nothing to hold the bottles together);
finally the fact that, by applying the horizontal wrapping in the second place, this latter is apt to tighten and retain the vertical wrapping, preventing it from accidentally slipping off.

It is anyhow understood that the invention is not limited to the particular embodiments described heretofore, which are merely examples not limiting the scope thereof, but that several modifications can be introduced, all within reach of an expert of the art, without thereby departing from the protection scope of the invention itself.

Claims

1) Method for packaging a group of objects, particularly a group of bottles, allowing to obtain a portable packing, wherein said group of objects is wrapped with two intersecting wrappings consisting of straps of plastic material, one of the wrappings extending on the vertical plane and forming also a gripping handle, characterized in that,

- to start with, the wrapping on the vertical plane is formed by feeding a first length of strap from the top over the group of objects and a second length of strap from the bottom under said objects, and by then joining together the leading and, respectively, the tail ends of the two strap lengths;

- subsequently, a second wrapping is formed on the horizontal plane using a strap of plastic stretching film, which is wound into several turns over the first wrapping so as to tighten it and block it against the group of objects; and

- said first strap length of the vertical wrapping is finally gathered up at the top so as to form a gripping handle.

2) Method as in claim 1) wherein said first length of strap is made of a polyethylene film having a thickness of 60/70 µm.

3) Method as in claim 2) wherein said second length of strap is made of a commercial type adhesive tape, which is applied with its adhesive surface facing upward, so as to adhere to the bottom of the objects and allow the leading and tail ends of the two straps to be joined together by simple adhesion of the ends of the second strap length onto the ends of the first strap length.

4) Method as in claim 2), wherein said first and second strap lengths each consist of a film of thermoweldable plastic material, and wherein the leading and tail ends of said strap lengths are joined together by thermowelding.

5) Machine for packaging a group of objects, particularly a group of bottles, allowing to form a portable packing by means of at least one wrapping consisting of a strap of plastic material extending in the vertical plane, so as to carry out the method according to claim 1), said machine comprising means to feed from the top a first wrapping strap, means to feed from the bottom a second wrapping strap, means to cut a first and a second strap length from said strap fed from the top and, respectively, from the strap fed from the bottom, and means to join together the leading and, respectively, the tail ends of said strap lengths.

6) Machine as in claim 5), wherein the top feeding means comprise a vertically movable feeding and cutting head.

7) Machine as in claim 6), wherein the carrying end of said head has a double-wedge configuration, a first part of the wedge being fixed and carrying a cutter and a second part being formed as a sliding block apt to protect said cutter.

8) Machine as in claim 7), wherein the bottom feeding means comprise a counterhead, apt to cooperate with the top feeding head at the end of its downstroke feeding the strap, the counterhead being in the form of a U clip with spring arms.

9) Machine as in claim 8), wherein the counterhead is vertically movable towards the feeding and cutting head, at the end of said movement the spring arms of said U clip opening elastically wide apart, so as to press onto the facing ends of the upper and lower strap lengths and join them together.

10) Portable packing for a group of objects, particularly a group of bottles, comprising two intersecting wrappings consisting of straps of plastic material, a first wrapping extending in the vertical plane and being gathered at the top so as to form gripping means in the form of a handle, and a second wrapping extending in the horizontal plane, characterized in that,

- said first wrapping consists of two strap lengths, a first length extending over the top of the group of objects and a second length extending under the bottom thereof, the leading and, respectively, the tail ends of the two strap lengths being joined together, one on top of the other, and in that,

- said second wrapping consists of a strap of plastic stretching material wound into several turns over the first wrapping and tightening this latter against said group of objects.

11) Portable packing as in claim 10), wherein said first strap length, extending over the top, consists of a polyethylene film having a thickness of 60/70 µm.

12) Portable packing as in claim 10), wherein said second strap length, extending under the bottom, consists of a commercial type polyvinylchloride or polypropylene adhesive tape.

13) Portable packing as in claim 10), wherein said group of objects consists of a group of six bottles positioned on two rows of three side-by-side bottles.