WO2009078051A1

WO2009078051A1 - Improvements to packs of tissue paper products, in particular packs of rolls, and relative methods and machines for their production

Info

Publication number: WO2009078051A1
Application number: PCT/IT2008/000742
Authority: WO
Inventors: Matteo Giardini
Original assignee: Kpl Packaging S.P.A.
Priority date: 2007-12-14
Filing date: 2008-12-04
Publication date: 2009-06-25
Also published as: EP2225159A1; ITFI20070280A1

Abstract

There is described a pack (1) of tissue paper products (R) comprising a plurality of products wrapped in a plastic film (F), wherein said plastic film presents a device for opening and closing the pack.

Description

"Improvements to packs of tissue paper products, in particular packs of rolls, and relative methods and machines for their production"

DESCRIPTION Technical Field The present invention relates to improvements to methods and devices for packaging tissue paper products, in particular but not exclusively for producing packs of rolls of tissue paper, such as toilet paper, kitchen towels and the like.

The present invention also relates to improvements to packs of tissue paper products, such as, but not exclusively, rolls of toilet paper, kitchen towels or other tissue paper rolls. Background of the invention

Tissue paper products, such as paper napkins and handkerchiefs, but above all tissue paper rolls, are packaged in packs or multipacks. Distribution through major multiples (shopping malls, supermarkets, hypermarkets and the like) leads to the tendency to use packs of increasingly large dimensions and containing a greater number or articles. However, this causes some problems and drawbacks during use. In fact, these packs are generally wrapped in heat-sealed plastic film. During initial use, i.e. when the user removes the first article, for example a roll of toilet paper or kitchen towel, the plastic film is torn and the pack remains open. In many cases the film breaks so that it no longer offers any protection to the remaining rolls or other articles, which can become soiled or deteriorate. The greater the number of rolls or other articles contained in each pack, the more this is true, as the larger the pack the longer it lasts. Summary of the invention

According to one aspect, the invention provides a new pack which solves or alleviates at least some of these problems, which comprises a plurality of products wrapped in a plastic film, and wherein the plastic film presents a zipper or other device for opening and closing the pack. When the opening and closing device is a zipper, it is advantageously formed by a zipper also produced in plastic material, of the type commonly known as "minigrip", "zip-lock" or similar trade names, which is advantageously welded along an intermediate cut provided in the plastic film that wraps a single pack. Alternatively, the opening and closing device can be formed by a strip of adhesive film, fastened firmly on one side to a part of the pack and provided with permanent adhesive on the opposite side with respect to the intermediate cut, so that it can be detached and re-attached several times without drying and ensures sufficient seal against external agents. In a further embodiment, the opening and closing device can be produced with the use of materials known with the trade name "Velcro".

Below, reference will be made specifically to a zipper, in particular a

"Minigrip" zipper. However, it must be understood that some of the advantages attainable with the present invention can also be achieved using other types of opening and closing devices. In general these will be reversible devices, i.e. devices which allow repeated opening and closing of the pack.

In this manner, the user can access the rolls or other tissue paper products contained in the pack without tearing the plastic film, but by opening the zipper. After removing the desired number of products, the zipper can be re-closed and the pack remains substantially intact, so as to keep the products remaining therein in optimum conditions.

Further advantageous features and embodiments of the pack according to the invention are described below and indicated in the appended dependent claims.

According to a further aspect, the invention relates to a method for producing a pack of rolls or other tissue paper articles or products, comprising a plastic wrapping film and a zipper for opening and closing the pack, comprising the steps of: - grouping together an orderly plurality of said products; preparing a portion of plastic packaging film;

- wrapping said orderly plurality of products in said portion of plastic film;

- closing, preferably by welding, the plastic film to form said pack; wherein the portion of plastic film comprises a zipper or other opening and closing device.

Further advantageous features and embodiments of the method according to the invention are indicated in the appended claims and will be described below with reference to some embodiment of the invention. According to yet another aspect, the invention relates to a device for forming packs of tissue paper products, in particular and preferably (but not exclusively) tissue paper rolls, comprising: a station for forming groups of products; a packaging station, in which the groups of products are wrapped in a plastic film to form single packs of products; and members to apply a zipper or other reversible opening and closing device to the plastic film, before, during or after production of the pack.

Further advantageous features and preferred embodiments of the device or machine according to the invention will be described below and are indicated in the appended dependent claims. Brief description of the drawings

The invention will be better understood by following the description and accompanying drawings, which show non-limiting practical embodiments of the invention. More in particular, in the drawing: Figure 1 shows a plan view of a machine for producing a pack according to the invention, in a first embodiment;

Figure 2 shows a schematic side view according to H-Il of Figure 1;

Figure 3 shows a schematic front view according to Ill-Ill of Figure 1 ;

Figure 4 shows an explanatory diagram of the feed of the film and of the products to be packaged in the machine of Figures 1 to 3;

Figure 5 shows a perspective view of a pack obtained with the machine of Figures 1 to 4;

Figure 5A shows an enlarged cross section of a zipper applied to the film for wrapping the pack, according to the line VA-VA of Figure 4; Figure 6 shows a schematic plan view of a modified embodiment of the machine;

Figure 7 shows a diagram illustrating feed of the film and of the products in the machine of Figure 6;

Figure 8 shows a perspective view of the pack obtained with the machine of Figure 6;

Figures 9 to 13 show an operating sequence of a different packaging machine to which the present invention can be applied; and

Figure 14 shows a pack obtained with the machine of Figures 9 to 13. Detailed description of embodiments of the invention - A -

Below reference will be made to packs containing tissue paper rolls, particularly rolls of toilet paper, although the packs described could also contain tissue paper products of different format, such as rolls of kitchen towels, rolls for industrial use, folded napkins either simply overlapped or interleaved, or other similar products. In general, the pack of the present invention is a pack containing single articles, each of which is formed by a plurality of individually usable elements. Each single article can be in turn packaged individually or a plurality of articles can be combined together, for example the rolls can be combined in pairs. With initial reference to Figures 1 to 5, in a possible embodiment the pack, indicated as a whole with 1 , comprises a plurality of tissue paper articles, in the example a plurality of rolls of toilet paper R, arranged in a plurality of layers, each of which comprises a series of rows of rolls. The articles or rolls R are wrapped in a thermoplastic film F welded along a longitudinal weld line L, along which two longitudinal edges of film are overlapped. On the front faces the pack 1 has four flaps folded against the flat front surfaces of the rolls R and welded.

In a suitable position, the pack 1 presents an openable and closable zipper indicated with 3 and formed by mutually complementary profiles made of plastic material, the one shaped as a male profile and the other as a female profile inside which the male profile can be inserted interlockingly to close the zipper. Zippers of this type are known and typically used to reversibly close and open plastic bags in particular for packaging foods. A diagram of a zipper of this type is represented in Figure 5A. These zippers are commonly known as "Minigrip", "Zip-lock" or the like and are described in numerous patents including GB 1.185.894, GB 1.1214.583, GB 1.156.170, GB 1.444.326, WO 2005/082731.

The zipper 3 can be applied in a suitable position on the pack. Preferably, the position will be chosen in order to facilitate removal of the articles packaged in the pack 1. If these (as in the example shown) are in the form of rolls, the zipper 3 and the relative opening, which is reversibly opened and closed therewith, will preferably be positioned along an area of the film in contact with the rolls, rather than in the intermediate areas between two consecutive tangent areas between roll and film. Preferably (as shown in Figure 5) the zipper 3 is positioned along an edge area, which facilitates removal of the articles once the zipper is opened. Figure 5 also shows with a dashed line a different alternative position of the zipper 5, in one of the tangent areas of the film with respect to the rolls contained in the pack. Again in Figure 5 a sort of security seal 4 is shown, which is removed the first time the pack is opened and which guarantees its integrity.

As can be seen in Figure 5A, the zipper 3 is applied to the film F along a substantially rectilinear cut that forms the opening to access the inside of the pack 1 , which will be produced by wrapping a group of rolls R with a portion of film F. Strips 3A, 3B of plastic material which form the zipper 3 are welded or glued to the edges at the cut. In a known manner, the zipper is formed by male 3C and female 3D profiles (produced on the strips 3A and 3B respectively), which mutually interlock. The male and female profiles extend approximately parallel to the length of the cut produced in the film F preferably for a length greater than the length of this cut. The zipper can be opened and closed repeatedly so that when the film F is wrapped around the pack 1 , opening of the zipper 3 allows the rolls or other articles R contained inside the pack to be accessed and removed. After the desired number of rolls have been removed the two profiles forming the zipper 3 are coupled again, thus closing the opening for access to the pack and allowing correct and hygienic storage of the remaining products R inside.

Zippers 3 of this type are already known and typically employed to close the mouths of plastic bags, i.e. they are normally applied to opposite flaps with parallel faces of a plastic manufactured product. In the present case, however, the strips on which the two mutually coupling profiles of the zipper are produced are on opposite faces of strips of plastic which overlap, but which are glued or preferably welded to a single sheet of thermoplastic film, along a cut produced in this sheet.

The length of the zipper 3 is such as to allow easy removal of single rolls R from the pack 1 , so that the user can remove single rolls from the pack re-closing it to keep the remaining rolls in hygienic conditions and protected from dampness and dust.

As mentioned previously with reference to Figure 5, an adhesive band to protect and seal the pack (indicated schematically with 4 in Figure 5) can advantageously be applied over the zipper 3 or part thereof. This adhesive or sealing band ensures the integrity of the pack at the time of purchase and will be removed by the final user when the pack is opened for the first time using the zipper. The adhesive band is advantageously applied in a step not shown, subsequent to application of the zipper 3 to the film F.

Alternatively, the film forming the pack can present a cut or perforation line under the zipper which, instead of being continuous, is cut or perforated at regular intervals to form a line that facilitates tearing. In the case of the present invention, the integrity of the line of discontinuous cuts or perforations guarantees the integrity of the pack at the time of purchase, preventing the risk of contamination by external agents.

A pack of this type can be obtained with various machines of known type, adequately improved and modified. Figures 1 to 3 show a first embodiment of a machine designed for this purpose. It can be formed more or less as described in the Italian patent no. 1.305.810, or it can present a configuration similar to that of machines by the same applicant, marketed with the name A5T, T100, CMW111 or others.

The general features of these machines are known and only the features required to understand the present invention will be described briefly below. In some embodiments the machine comprises a line 5 to feed layers of products R towards an elevator platform 7. A plurality of layers of products or rolls R are positioned on the elevator surface and subsequently transferred to a series of pushers 9 above. Consecutive pairs of pushers 9 define seats 11 to house groups of rolls R, which must be inserted in single packs 1. The pushers 9 feed the single groups of products or rolls R along a substantially horizontal conveyor surface 13 towards an area for folding and welding the front flaps of the plastic film wrapping the pack.

To wrap the group of rolls R in the plastic film F, a portion of this film is extended by feed and cutting means, described briefly below, over an opening 13A of the conveyor surface 13. When the elevator 7 lifts the group of layers of rolls R, these are consequently wrapped on three sides by the plastic film F. Horizontal folding planes then wrap the fourth face of the group of articles or rolls R and a welding device, known and not described, performs welding of the longitudinal flaps L. By moving the group of rolls R thus wrapped towards folding 15 and welding 17 means, the front flaps are lowered and welded against the front surfaces of the pack to obtain complete closing thereof.

The film F is fed to the machine from a reel B resting in a cradle formed by rollers 19 (Figure 2) and which can be arranged with the axis parallel or orthogonal to the direction of feed of the pushers 9. The first solution is shown schematically in Figures 2 to 5 while the second solution is shown schematically in Figures 6 to 8. As will be clarified below, in both cases the zipper 3 is applied to the film with an orientation substantially parallel to the longitudinal extension thereof, i.e. parallel to the direction of unwinding of the film from the reel B.

Figure 2 shows a diagram of the path of the film towards the pushers 9, which can be used both in the configuration with the reel disposed with the axis parallel to the movement of the pushers 9 and in the configuration with the axis of the reel orthogonal to the movement of the pushers.

The path of the film F extends from the reel towards a series of drive rollers 21 ,23, 25, one of which preferably with movable axis (dancer roll) to allow a variation of the feed speed of the film from the reel for the reasons clarified below. Arranged downstream of the roller 25 is a brake, actuated by an actuator 27A to stop the film during the step to apply the zipper 3. Provided downstream of the brake 27 is an area for application of the zipper 3, in which a cutting blade 29 is provided, which cooperates with a counter- blade 31 to produce a cut in the film approximately the same length as the zipper 3. This is applied, by gluing, welding or in another suitable manner, by an applicator generically indicated with 33. A photocell 35 is provided in a suitable position to detect a notch printed on the film F which determines the position in which the cut must be produced in the film and the zipper 3 must be applied, in the manner clarified below.

Arranged downstream of the photocell 35 is a film storage unit formed by a series of idle rollers 37 with fixed axis and a series of idle rollers 39 with movable axis. The reciprocal distance between the rollers 37, 39 varies when the feed speed of the film through the area for cutting and applying the zipper 3 varies. The numeral 41 indicates a possible further photocell which detects the position of the photocell notches on the film to activate a perforating or cutting blade 43 rotating and cooperating with a fixed counter-blade 45 to divide the film F fed continuously from the reel B into single portions separated by transverse perforation lines. Each section or portion of film F between two perforation lines generated by the rotating blade 43 is then detached from the subsequent section to form the sheet to wrap and package a single pack 1.

The numeral 47 indicates drive rollers, at least one of which is motorized, to unwind the film F from the reel B towards the packaging area. Arranged downstream of the blade 43 and counter-blade 45 are two pairs of belts 48, 49. Each pair of belts (only one of which is shown in the side view of Figure 2) engages an edge of the film, so as to feed the extended film towards the opening 13A of the conveyor surface 13. Arranged downstream of the two pairs of belts 47, 49 are a further two pairs of belts 48A, 49A, controlled at variable speed, to tear the single sections of film F along the perforation lines. The perforation lines are mutually phased so that a zipper 3 is applied between each pair of lines, in a position such as to be located on a lateral face of the pack 1 , while the end bands of the cut sheet of film F form the flaps folded on the front faces of the pack. The position of the zipper 3 with respect to the edges of the sheet of film F is shown schematically in Figure 4 for the configuration in which the film is fed from a reel B arranged with the axis A-A thereof parallel to the direction of feed of the pushers 9. The longitudinal flaps which are welded along the line L of the pack 1 are indicated with L1 and L2, while the band of the sheet of thermoplastic film F which when folded forms the welded front flaps of the pack is indicated with L3. Orientation of the zipper 3 facilitates pulling of the film F by the drive rollers 47. In fact, these rollers can have an annular groove along the area in which the zipper 3 passes, so as not to interfere with it. In general the drive rollers 47 are formed by rotating shafts, at least one motorized, which carry rollers of lesser axial length than the width of the film F, disposed so that the zipper 3 is fed between two axially aligned rollers. In Figure 4 the direction of feed of the film is indicated with fF and the direction of feed of the rolls R is indicated with fR.

Operation of the machine described above is as follows. During the formation of a series of layers of articles, such as rolls R or the like, on the elevator platform 7 (according to a known procedure), a section or portion of film F is fed through the means described above until it is positioned extended over the opening 13A. The respective zipper 3 is preferably located over the opening 13A, so that when the elevator 7 is raised, the zipper 3 is located on the lateral surface of the pack which, in the first packaging step, is located on the top part of the group of rolls R. When raised, the elevator 7 is located approximately at the level of the conveyor 13 and in a known manner the flaps L1 of the film are overlapped under the group of articles or rolls R. The pushers push the pack thus formed towards the folders and welders which close the pack.

Movement of the film F is substantially continuous at approximately constant speed downstream of the storage unit 37, 39, while upstream of this storage unit feed can be cyclically interrupted to allow application of the zippers 3 to each portion of film F, which will subsequently be defined between two consecutive perforation lines. Stepped feed of the film F is possible due to the brake 27 which cyclically stops the film and to the storage unit 37, 39 which allows continuous feed of the film in the area downstream, thus making the operations to apply the zippers 3 independent from the operations to perforate and tear the portions of film. In the example shown, two photocells 35, 41 have been employed to control application of the zippers and execution of the perforations by means of the rotating blade 43, but it must be understood that in other embodiments only one photocell can be provided to detect the notches on the film and synchronize operations thereon. When the reel B is arranged with its axis orthogonal to the direction of movement of the pushers 9, the structure of the members for applying the zipper, perforating the film and tearing the single sections can be substantially identical, except that the section of film and the zipper 3 are positioned in the manner shown in Figure 7 with respect to the group of rolls R. The same numerals indicate the same or equivalent parts to those of the embodiment shown in Figure 4. The pack obtained is represented schematically in Figure 8, in which it can be seen that the orientation of the zipper 3 is rotated through 90° with respect to the orientation it presented in Figure 5. The concept underlying the invention can also be embodied in other packaging machines, for example of the type described in WO-A- 2007/046126, to which specific reference can be made for greater constructional details of these machines and their operation. Figures 9 to 13 schematically show the characteristics of these machines relevant for the purposes of the present description, while Figure 14 schematically shows a pack 1 obtained with this machine.

The groups of rolls R are fed between two substantially parallel walls 51 , 53 by a pusher 55, so as to wrap the group of rolls R on three sides with a sheet or section of thermoplastic film F positioned in front of the path of the rolls R. The film is held taut by temporary stop members 57 with a zipper 3 applied to the film F in the same manner as described previously with reference to Figure 2 and preferably positioned in the area that will subsequently wrap a smaller lateral face of the final pack. Downstream of the area in which the film F is positioned a rotating drum

59 is located, which carries a series of parallel belts 61 , 63, between which the group of rolls R partly wrapped in the plastic film F is placed. The belts 61 , 63 cooperate with the pusher 55 to advance the pack being formed.

The drum 59 carries fixed folding elements 65 which fold the flaps of the film that project laterally from the pack. Once the group of articles or rolls R has been pushed into the drum 59 between the upper and lower belts 61 , 63, the drum is rotated through 180° and the belts 61 , 63 are made to move again to eject the pack being formed, so as to cause closing of the front flaps of the film F through further folders 71 , 73 and 75. The numeral 77 indicates a welder to weld the overlapped longitudinal flaps of the film F and 79 indicates a front welding device of the four flaps of film which have been folded on each front face of the pack 1.

The entire operating cycle described above is known and can be subject to variations, for example as a function of the form of the folding means, of the welding means or of other features of the machine. For example, the drum 59 can be omitted and folding of the lateral flaps of the sheet of thermoplastic film F can be obtained with movable rather than fixed folders.

Regardless of the structure of the machine, the portion of film F, which is positioned between the members 57 has previously been provided with a zipper 3 with a system similar to the one described with reference to Figure 2, or in another suitable manner. In this way, also in this case the pack 1 which is obtained is provided with a zipper 3. It will preferably be placed on one or on the other of the two smaller sides of the pack 1 , as schematically indicated in Figure 14.

Moreover, it would also be possible to apply the zipper to the pack in a different manner to the one shown in the drawing. In fact, it is possible to apply the zipper after the film has already started the folding steps, either during one of the folding steps or after this folding has been completed and even after the pack has been fully closed. Preferably, cutting of the film takes place in a previous step, so as not to damage the wrapped products. In fact, the geometry and the operating function of folding machines allow the zipper to be applied during one of the dwell steps or immediately downstream of the pack closing position.

It is understood that the drawing shows just one example, provided merely as a practical demonstration of the invention, which can vary in its forms and arrangements, without however departing from the scope of the concept underlying the invention. Any reference numbers in the appended claims are provided to facilitate reading of the claims with reference to the description and to the drawing, and do not limit the scope of protection represented by the claims.

Claims

1. A pack of tissue paper products comprising a plurality of products wrapped in a plastic film, characterized in that said plastic film has a device for opening and closing the pack.

2. Pack as claimed in claim 1 , wherein said products are articles each composed of a plurality of individually usable elements.

3. Pack as claimed in claim 1 or 2, characterized in that said opening and closing device is a zipper.

4. Pack as claimed in claim 1, 2 or 3, characterized in that said zipper or opening and closing device is produced in plastic material and fastened, preferably by welding, along edges of an opening produced in said film.

5. Pack as claimed in claim 4, characterized in that said opening in the film is formed by a cut.

6. Pack as claimed in claim 4, characterized in that said opening in the film is formed by a perforation of the film.

7. Pack as claimed in claim 4 or 5, characterized in that said opening and closing device is a zipper of the type known as "minigrip", "zip-lock" or the like.

8. Pack as claimed in one or more of the preceding claims, characterized in that said opening and closing device comprises two strips of plastic material, provided with male and female profiles, couplable by interlocking, said two strips being applied to a face of said film along a cut produced therein.

9. Pack as claimed in one or more of the preceding claims, characterized in that it comprises, on each of two opposite front faces, four flaps of plastic film folded against the front surfaces of said products and closed by heat-sealing and, on a lateral surface arranged between said two front surfaces, a weld between overlapped longitudinal flaps of said film.

10. Pack as claimed in claim 9, characterized in that said opening and closing device or zipper is applied to said lateral surface of said plastic film, between the two opposite front faces of the pack.

11. Pack as claimed in claim 10, characterized in that between said two front faces said pack is provided with a pair of smaller sides and a pair of greater sides, said opening and closing device being arranged on one of the two opposite greater sides of the pack.

12. Pack as claimed in one or more of the preceding claims, characterized in that said opening and closing device is arranged along an edge area of the pack.

13. Pack as claimed in one or more of the preceding claims, characterized in that said products are rolls of tissue paper.

14. Pack as claimed in one or more of the preceding claims, comprising a security seal associated with said opening and closing device.

15. Method for producing a pack as claimed in one or more of the preceding claims, comprising the steps of: grouping together an orderly plurality of said products; preparing a portion of plastic packaging film; wrapping said orderly plurality of products in said portion of plastic film; - closing the plastic film to form said pack; characterized in that said portion of plastic film is provided with an opening and closing device.

16. Method as claimed in claim 15, characterized in that said opening and closing device is a zipper.

17. Method as claimed in claim 15 or 16, characterized in that said portion of plastic film is fed to a packaging station, said opening and closing device being applied to the plastic film while said film is being fed to the packaging station.

18. Method as claimed in claim 15 or 16, characterized in that said portion of plastic film is fed to a packaging station, said opening and closing device being applied to the plastic film after it has been at least partly wrapped around a group of products to be packaged.

19. Method as claimed in claim 15 or 16, characterized in that portions of plastic film coming from a reel are fed in sequence to said packaging station, to wrap single packs of products in succession, and in that an opening and closing device is applied to each portion of plastic film before cutting said portion of plastic film.

20. Method as claimed in claim 19, characterized in that a portion of the plastic film is stopped and said opening and closing device is applied to said portion of plastic film when it is substantially stopped.

21. Method as claimed in claim 20, characterized in that a store of plastic film is formed between an application station for the application of the opening and closing device and said packaging station, and in that the plastic film is temporarily and sequentially stopped in said application station to apply thereto said opening and closing device, while a portion of plastic film already provided with a respective opening and closing device is fed to the packaging station downstream.

22. Method as claimed in one or more of claims 15 to 21 , characterized in that said plastic film is cut, perforated or slit along a substantially straight line, of a length approximately equal to an opening of said pack closed by said opening and closing device, and in that said opening and closing device is applied along said line, preferably by welding.

23. Method as claimed in claim 22, characterized in that said substantially straight line is parallel to a direction of feed of the plastic film.

24. A device for forming packs of tissue paper products as claimed in one or more of claims 1 to 14, comprising a station for forming groups of products and a packaging station, wherein said groups of products are wrapped in a plastic film to form single packs of products; characterized by application members to apply an opening and closing device to said plastic film.

25. Device as claimed in claim 24, characterized in that said application members comprise a cutting, perforating or slitting member to cut, perforate or slit said film along an intermediate line between opposite edges of the film, and an applicator member to apply an opening and closing device along a cut, slit or perforation line, produced on said plastic film by said cutting, slitting or perforation member.

26. Device as claimed in claim 24 or 25, characterized by an unwinder to unwind a plastic film from a reel; a cutting member to cut single portions of plastic film to wrap single groups of products and form packs of products; an applicator of opening and closing devices, to apply an opening and closing device to each portion of plastic film.

27. Device as claimed in claim 24, 25 or 26, characterized in that along the feed line of the plastic film from said reel to said packaging station, a temporary stop area of the plastic film is provided for application of the closing devices.