WO2017211568A1

WO2017211568A1 - Method for producing a drinking cup comprising a sidewall pinched and glued in the upper portion of same, and resulting drinking cup

Info

Publication number: WO2017211568A1
Application number: PCT/EP2017/062029
Authority: WO
Inventors: Neindre Jean-Luc Le
Original assignee: Neindre Jean-Luc Le
Priority date: 2016-06-07
Filing date: 2017-05-18
Publication date: 2017-12-14
Also published as: FR3052151A1; FR3052151B1

Abstract

The invention proposes a method for producing a drinking cup intended to contain liquid, comprising a circular bottom and a sidewall (1) in the form of a sheet provided with two opposing sides (2), the method comprising a step consisting of rolling the sheet around itself in such a way as to produce a truncated cone, and sealing the side of the sidewall (1), referred to as the "lower" side (41), to the periphery of the bottom so as to give the drinking cup a volume provided with an opening in the top portion, said opening being delimited by two opposing edges (421, 422) located on the side referred to as the "upper" side (42) of the sidewall (1). According to the invention, the method comprises a step of gluing the two edges (421, 422) of the opening, that consists of pinching them in order to bring them into contact without folding them, the gluing being carried out, at most, on a portion of the opening, so as to leave an open hole allowing a liquid contained inside the volume to flow through same.

Description

Method of manufacturing a cup having a pinched flank and glued in its upper part, and cup derived from the process

1. DOMAIN OF THE INVENTION

The field of the invention is that of the manufacture of a disposable cup having a bottom and a sealed sidewall around this bottom and forming a truncated cone having an opening at the top. The invention relates more particularly to the fact that the cup is closed by bringing the edge of the opening to paste while leaving a narrow orifice for the flow of the liquid contained in the cup.

2. TECHNOLOGICAL BACKGROUND

It is known disposable cardboard cups coated with a material ensuring tightness inside. The generally frustoconical shape of these cups makes it possible in particular to stack them so as to reduce the storage volume. Stacking of the cups can be done in cylindrical dispensers with a tightening at the base, allowing the last cup to be removed from below. Once the cup empty in hand, an operator puts it under a dispensing tap and fills it with a liquid controlled by a consumer. To facilitate transport, the operator places a plastic lid on the top of the cup and through a preformed hole in the lid, can slip a straw. The circular shaped lid has a perimeter flap enclosing the upper edge of the cup, closing it almost hermetically. The consumer can move with the cup closed by hand without its contents spreading.

Nowadays, environmental constraints encourage manufacturers to use as few disposable plastic elements as possible. It therefore seems desirable to find a substitute for the lid and possibly straw, without increasing the cost of the cup.

An alternative is to use one or more flaps that extend up the side of the cup. It is also known that this type of flaps is used to manufacture brick-shaped containers of parallelepiped shape having on the top a welded plastic valve with a plug. By unscrewing the cap, a lid is torn to give access to the liquid inside, the valve serving as a spout. This embodiment involves the use of a plastic element that is generally not biodegradable.

According to other known embodiments, at the end of filling, the operator folds one or more flaps so as to close the opening. Such flaps are taught by the document WO 2013/175020 published on November 28, 2013. In this document, two lateral flaps are lowered to form a curved upper surface opening on either side by two orifices located on each side of the flaps. , the consumer using these orifices to drink.

The straw can be made in the body of the flank of the cup. Such a straw is described in particular by the document US6155478, published on December 5, 2000. This document teaches that the lateral end of the sheet constituting the side of the cup is wound inward to form a conduit, the inner surface of the flank of the cup extending to become after gluing the inner surface of the straw.

It is therefore desirable to provide a new method of manufacturing a cup respecting the environment, having means for transporting it without its container spills and is manufactured with simple and inexpensive means. 3. STATEMENT OF THE INVENTION

In a particular embodiment of the invention, there is provided a method of manufacturing a cup for containing liquid having a circular bottom and a sidewall in the form of a sheet with two opposite sides . The method comprises in particular a step of winding on itself the sheet so as to make a truncated cone, and seal the side of the flank said "lower" to the periphery of the bottom so as to give the cup a volume with a round opening at the top, said opening being delimited by two edges facing each other and located on the said side

"Superior" of the flank. The method further comprises a step of bonding the two edges of the opening by pinching them to bring them into contact without bending them, the gluing being effected on at least part of the opening so as to leave an open orifice allowing a liquid contained in the volume to flow.

In this way, the opening of the cup is almost closed following a simple pinching operation followed by gluing, without making any folding. The bonding does not take place on all the edges, which has the effect of leaving a small free orifice. The consumer uses this orifice as a means of flow and therefore no longer needs a plastic element to open and close the cup. In addition, the cup can be made of a single material, which is preferably biodegradable or compostable, which facilitates both its manufacture and its recycling.

The cup according to the invention is manufactured according to the usual techniques from a blank of cardboard. However, the bonding of the two edges of the opening is partial and permanent (the glued portions of the edges are not intended to be open), and does not require further addition of material. The sealed closure of the cup is obtained by pinching the upper border of the cup so as to bring the edges closer and to stick them on a part only.

Advantageously, the nip of the two edges is performed without folding.

According to a particular aspect of the invention, the upper side of the sidewall intended to form the opening is covered with an adhesive on a length less than a circumference of the opening leaving an uncoated length, the sealing of the edges of the opening. opening of contacting the coated surfaces.

This sealing of the edges of the opening is of the glue-on-glue type, for example.

When the cup is provided with a straw, the glue also covers the outer surface of the straw, the upper side of the sidewall to form the opening being covered with an adhesive on the entire circumference of the opening, the inside straw constituting the unsealed area (corresponding to the orifice).

According to a particular aspect of the invention, the sheet forming the sidewall is covered at least in the upper part on at least one side of a thermoplastic material which is heat-welded.

According to a particular aspect of the invention, the two edges facing each other and located on the so-called "upper" side of the sidewall each comprise an extra thickness at the opening intended to prevent the liquid contained in the cup from flowing out when the latter is reversed.

According to a particular aspect of the invention, the lower side of the sheet forming the sidewall has a curved line having at least three points of inflection.

The bottom of the cup takes a flat shape after the step of pinching and gluing the opening. According to a particular aspect of the invention, the inner surface of the sidewall of the cup comprises a bead extending under the sealing strip, the bead present on one edge of the opening coming into contact with the bead present on the other edge. during the sealing step.

The embossing constitutes a seal, which prevents the liquid from coming into contact with the glue and being contaminated by the latter.

According to a particular aspect of the invention, near the orifice, the opening has an indentation at an edge and an advance at the opposite edge.

According to a particular aspect of the invention, the cup has lines of weakness on the sidewall conforming to the shape of the indentation and the projection.

These lines of weakness are formed on both sides of the flank for example.

According to a particular aspect of the invention, the edge-pinching step is carried out using an apparatus provided with at least two grippers moving towards each other at the height of the edges of the invention. opening, at least one clamp having a continuity rupture zone not permitting bonding on the portion of the edge of the opening forming the orifice.

This claim covers the use of an apparatus for making the cup, whether the latter is welded with thermoplastic or an adhesive.

According to a particular aspect of the invention, the cup has lines of weakness in the upper part of the sidewall, the lines being vertical and facing each other when the cup is formed at the end of the gluing step.

According to a particular aspect of the invention, a lateral side said "first" of the sidewall sticks to the opposite side side said "second" of the sidewall during the winding step to give the cup a volume, the method further comprising a step of winding on itself the first lateral side to form a pipe whose inner surface is formed by a portion of the outer surface of the sidewall, and a step of bonding the outer face of the pipe thus formed on the inner surface of the second lateral side, the outlet of the pipe forming the orifice following the step of bonding the two edges of the opening.

According to a particular aspect of the invention, the thermoplastic material is removed or absent from the surface intended to become the inner wall of the pipe.

In another aspect of the invention, there is provided a cup for containing liquid, which cup is manufactured according to the method described above.

In another aspect of the invention, there is provided a device for manufacturing a cup according to the method described above, said device having two clamps movable towards each other moving at the height of the edge of the opening.

According to a particular aspect of the invention, at least one clamp comprises a continuity breaking zone that avoids gluing on the part of the edge of the opening forming the open orifice.

According to a particular aspect of the invention, the device comprises a tool having a role of thermal insulator or adhesive, being inserted between the edges of the opening at the orifice.

4. LIST OF FIGURES

Other features and advantages of the invention will appear on reading the following description, given by way of indicative and nonlimiting example, and the appended drawings, in which:

FIGS. 1a, 1b and 1c show an exemplary embodiment of a cup flank intended to stick to a bottom, FIGS. 2a, 2b and 2c show a first embodiment of a cup equipped with a straw for extracting the liquid contained therein,

FIGS. 3a, 3b and 3c show another embodiment where the straw is placed at one lateral end of the opening,

FIGS. 4a, 4b and 4c show another embodiment where the orifice is at a lateral end of the two edges of the opening,

- Figures 5 and 6 show two variants of a cup with a straw,

FIGS. 7a to 7c show an exemplary embodiment of the cup in which the bottom is applied once the upper edges are momentarily close together,

FIG. 8 shows a detail view of the lower part of a sidewall in a staggered view according to a particular embodiment,

FIG. 9 shows a method of manufacturing a cup consisting of first gluing the truncated cone-shaped flank and then applying the bottom to it at its lower part by means of a tool,

- Figures 10 and 11 show in perspective a cup before and after bonding the opening, the bottom has depressions and waves,

FIGS. 12a and 12b illustrate a production method using a production apparatus for manufacturing a cup described in the preceding figures,

FIGS. 13a, 13b and 13c show various phases of the step of manufacturing a cup during which the bottom is caused to deform so as to have no hollow, - Figures 14a to 14c show another embodiment in which the upper edges of the cup implement sealing flanges. 5. DETAILED DESCRIPTION OF THE INVENTION

In all the figures of this document, identical elements are designated by the same reference numeral.

Now, with reference to FIGS. la, lb and the, an embodiment of a cup. The cup contains a volume delimited on the sides by a flank 1 consisting of a sheet which is shown spread in Figure la. This sheet has two lateral sides 2 intended to come into contact by sticking to each other, the lateral sides 2 coming to overlap at a sealing strip 3. The side 1 has a lower side 41 intended for sticking around the periphery of a bottom, and an upper side 42 having a sealing strip 5 extending over a portion at most of the upper side.

The method for producing a cup consists first of all in winding the sheet on itself to make a truncated cone open on both sides then to seal the lower side 41 of this sheet around the bottom of the cup so as to give it a volume accessible from the top through a round opening. The upper side 42 of the sidewall then surrounds the opening of the cup forming two edges 421, 422 facing each other, these two edges 421, 422 are visible in FIG. la on each side of a line of weakness 101 (represented by a dashed line) extending on an upper part, in the middle of the sidewall and to focus the folding when closing the cup. Then, the two edges 421, 422 are pinched to bring them into contact without folding, the bonding being effected over a portion of the aperture so as to render sealing the junction while leaving an open port allowing a liquid poured into the volume to flow.

Disposable cups are preferably made of cardboard coated with thermoplastic material, preferably recyclable, or even biodegradable, especially using a thin film of polyethylene or biopolymers. Closure of the cup opening is achieved by exerting pressure on both edges of the cup opening and sealing them. The sealing can be carried out in various ways, for example gluing, heat-sealing or any other method of assembly, depending in particular on the material present on the surface. The thermo-sealing makes it possible to glue the side of the cup without using glue. This operation requires adding a heat-emitting means on the edge-contacting means and disposing on the surface to be sealed of the cup, at least one thin film of thermoplastic materials, preferably biopolymers or polyethylene.

According to one particular embodiment, the tacky surface may be obtained by depositing a glue so as to form a self-adhesive scrub of the "glue on glue" or "contact glue" type. This means that the mere contact between two surfaces covered with such a substance produces an almost instantaneous bonding. It also means that the contact of a surface covered with such a product with another type of surface causes no bonding. This type of glue is for example synthetic based on natural latex whose properties allow it once dry not to stick to the paper, but to stick on itself. The inside of the edges of the opening being coated with glue, the pinching of the edges causes the bonding and ensures a tight closure of the cup. When stacking, there is no risk of sticking the cups together, since only their inner surface is coated with glue. In this embodiment, the pinching of the edges of the cup can be done by hand, or advantageously using a press or a manual or automatic clamp, preferably connected to a cup filling apparatus.

According to one particular embodiment, the heat-sealing of the edges of the opening is carried out by ultrasound for example (by means of a sonotrode for example), by high frequencies or any other heat-sealing means suitable for the food field. .

Figs. lb and show in perspective the cup thus produced. According to an improvement, the orifice is in the middle of each of the two edges 421, 422 of the opening. An edge 421 sees its height with respect to the bottom diminish towards the middle by making an indentation 6, constituting a recessed part in the flank of the cup, whereas the opposite edge 422 sees its height with respect to the bottom increase towards the middle by realizing a advanced 7 constituting a bulging portion. Once the edges 421, 422 bonded, this arrangement allows the realization of a true spout 10, as shown in Fig.lb and the. The opening of the spout 10 is effected by manually pressing the side edges of the cup, as illustrated by the two arrows of Figures lb and the. When the consumer releases them, the advance 7 and the notch 6 come closer again and close the goblet.

This first embodiment is more particularly adapted to the distribution of hot drinks. The liquid can flow easily on the advance 7 and the air replacing the elapsed volume can easily be introduced through the notch 6. If the consumer drinks directly to the cup, he can put his lower lip in contact with the Advanced 7 and place the notch 6 just below his nose.

According to one improvement, lines of weaknesses 8 (visible in Figure la) are arranged around the notch 6 and the advanced 7. Under the pressure of the operator or the consumer, these lines of weakness allow to easily fold the notch 6 and the advanced 7 to enlarge the orifice and thus facilitate the payment. The rounded shape of the lines of weakness 8 extends laterally, the circular arc rounding downwards to facilitate the enlargement of the orifice.

According to an improvement, the embodiment thus described also comprises a bulge, curved or cocked hat top of the two edges 421, 422 of the upper side 42, at the spout 10. This provision has the advantage of provide a greater comfort of use: the spout 10 is thus removed from the body of the cup, which allows a better grip in the mouth without the sides of the cup being in contact with the commissures of the lips.

Figs. 2a, 2b and 2c, show a first embodiment of providing the cup with a pipe forming an integrated straw to allow suction of the liquid contained in the volume. This variant is particularly suitable for dispensing cold drinks. According to this embodiment, the straw 11 is made at the same time as the cup and with the same material. As shown in FIG. 2a, the straw 11 consists of a pipe comprising a plurality of flat and straight flanks, the sides of which are marked by lines of weakness 9. One end of the straw 11 thus formed opens on the opening and the other end opens at the bottom of the cup. The flanks of the straw are placed at the side side of the sidewall after the sealing strip 3. In a particular embodiment, the straw 11 takes shape by manually pressing the two lateral sides of the opening which has the effect of bringing them closer, this movement allows the flanks of the straw 11 to be spread apart and thus to increase its section. The straw 11 opens into the cup through a cut hole 111, for example of triangular shape, as shown in FIG. 2a. The shape of this orifice 111 may change. The straw is placed in Figs. 2a, 2b and 2c, in the middle of the edges of the opening, but it can take place at any other place, such as for example at a lateral end, as will be described in the following figures. To facilitate the taking in the mouth and to the extent that the straw 11 does not exceed the height of the opening of the cup, the shape of the edge at its location has an advance 12 to facilitate the intake in the mouth, in the same way as progress 7 described above.

During the process of making the cup with a straw, care should be taken not to glue the inner sides of the straw, so as not to close it and to be able to use it when the cup is filled with liquid . To avoid this situation, the method of manufacturing such a cup provides that the inner wall of the straw can not be glued. One way of doing is that the portion of the sidewall constituting the straw 11 has a single layer of thermoplastic material, and that this layer is not inside the straw.

Different embodiments for placing a straw in the cup will now be described in connection with the manufacturing process. The first two modes are usable when the manufacturing material comprises two layers (inner and outer) of thermoplastic material. According to a first embodiment, the thermoplastic layer is removed on the surface intended to become the inner wall of the straw. The removal of the material is carried out by scraping the surface, this operation can be carried out just before the manufacture of the cup and in particular at the same time as the cutting of the sheet constituting the sidewall 1.

According to a second embodiment, the surface intended to become the inner wall of the straw is covered with an inert material which does not adhere with another material, while respecting the constraints. food. By way of example, it is possible to affix on this surface a thin film of hydrophobic paper obtained by chromatogeny or a single layer of cellulose monocrystals, or a biodegradable type silicone paper.

In the case of a third embodiment, the sidewall of the cup has a single layer of thermoplastic material, which is placed inside the cup. The straw is made by winding the surface, the non-thermoplastic surface being turned inwards. Two particular embodiments will be described later.

According to an improvement, the upper end of the straw stops at the edge of the cup, which facilitates storage. The fact that it can be flattened also facilitates stacking and does not increase the storage volume.

According to an improvement, lines of weakness 9 vertical are also placed in the upper part of the flank at its center, so that they face the lines of weakness 9 of the walls forming the straw 11 when the cup is formed at the end of the bonding step of the sides of the flank. These lines of weakness 9 facilitate the opening of the straw and the separation of the sidewall when the user applies pressure on the side edges in the upper edge of the cup, as illustrated by the arrows of Figures 2b and 2c.

Figs. 3a, 3b and 3c, show another embodiment where the straw is placed at a lateral end of the opening of the cup. Fig. 3a shows more particularly the sealing strip 5 which extends over a part at most of the upper side, the part devoid of bonding means extending inside the straw 11. FIGS. 3b and 3c, profile the cup with the orifice closed, and exerting pressure as shown by the arrow, the cup with the open port. Figs. 4a, 4b and 4c, show another particularly simple embodiment, where the orifice is at a lateral end of the two edges of the opening. In this mode, the portion of the opening devoid of bonding means is at a lateral end 2 of each edge. The orifice 13 can be opened by a simple pressure in the angle of the cup, in the direction indicated by the arrows of FIGS. 4b and 4c. This orifice can be used as a spout or as an access means to the interior for including receiving a straw.

Figs. 5 and 6 show two different examples of making a cup with a straw 11. The lateral side of the sheet supporting the straw is wound by forming a pipe placed inside the cup. In the embodiment described in FIG. 5, only the inner surface of the cup has a layer of thermoplastic material. In this case, to form the wall of the straw, the side end 3 of the cup flank first goes to the inside of the cup, and then folds to join the other side of the sheet. In this embodiment, the inner face of the straw which is covered with thermoplastic material is at the end of a winding of the straw on itself, join the outer face to adhere.

In the embodiment described in FIG. 6, the two surfaces of the cup may be covered with a layer of thermoplastic material. In this case, the lateral end 3 of the cup flank first comes into contact with the inner surface of the other side side of the sheet and then rolls towards the inside of the cup to form the wall of the straw. , and sticks on the inner surface of the sidewall. In this embodiment, the outer surface of the straw which is covered with thermoplastic material sticks to the inner surface of the other side side, that is to say the inner surface of the cup. In this mode, to avoid closing the section of the straw, care should be taken to make the inner wall of the non heat-sealable straw, according to one of the techniques described above.

Figs. 7a to 7c show an embodiment of the cup by applying the bottom after gluing. In a first step, the two edges facing each other of said round opening are pinched to bring them together avoiding sticking them (upper arrows of Fig. 7b). To avoid sticking, it is possible not to put them in contact, or to temporarily place a non-adhesive element between the two edges. This operation has the effect of deforming the lower side of the sidewall, In this position, the bottom 4 is sealed at the lower side 41 of the sidewall (lower arrows of Fig. 7c). Once glued and after separation of the edges, the bottom 4 is deformed to adapt to the shape of the sidewall and thus produce a convex bottom (FIG 7c).

Fig. 8 shows a particular form of the cut sheet of a flank partially flat view.

When pinching the top of the cup, the high edges come closer and are pressed to establish the one-part welding only to ensure tight closure of the cup. At the same time, the corresponding bottom edges of the cup spread apart as they rise.

This is why the cup has low waves and hollows at the bottom, which make it unstable when it is open but which allows it to regain its stability once closed.

Thus, the lower side 41 of the sidewall is not cut along a straight line but along a curved line comprising a succession of waves

21, and hollow 22, this line having three points of inflection. The radii of curvature of the curved portions of this curved line are calculated according to the size of each cup. Fig. 9 shows another method of manufacturing a cup consisting of first glue the truncated cone-shaped flank and then to apply the bottom to it at its lower portion 41. The lower portion 41 of the flank has the shape illustrated in FIGS. Fig. 2c, that is to say without wave and hollow, and the bottom 4 is brought under the truncated cone with a tool 14. This tool 14 has the shapes of waves and troughs that the it is desired to obtain for the bottom of the cup. The tool 14 exerts a pressure which closes the edges of the bottom of the cup on the bottom 4 of the cup by welding by making it take the shapes of hollows and waves. In this way, the manufacture of the cup is facilitated and the bonding of the sidewall with the bottom is ensured.

Figs. 10 and 11 show in perspective a front cup (Fig. 10) and after (Fig. 11) bonding of the opening whose bottom has depressions and waves. According to an improvement, the bottom 4 has lines of weakness 23 to facilitate its shaping so as to facilitate the realization of the waves 21 and the recesses 22. In FIG. 11, the opening is glued and the bottom is flat.

According to an improvement, visible in FIG. 4a, the inner surface of the cup flank has a bead 25 extending along the edge under the sealing strip. This bead 25 made by embossing or embossing, present on the first side of the opening comes into contact with the same bead present on the second side during the sealing step. This bead 25 isolates the sealing strip 5 from the inside of the cup which contains liquid food. In this way, the cup container can not come into contact with the glue.

Fig.12a and 12b illustrate a manufacturing method using a production apparatus for the manufacture of a cup described above. This device has two tongs 16 movable towards each other moving at the height of the edges of the opening of a cup placed between they. The clamps 16 act as vices to exert pressure on the edges and put them in contact for their bonding.

According to an improvement, in addition or not because the cup has a portion of the non-sticky opening, part of the length of at least one clamp 16 has a break zone 17 which does not allow to glue the edges of the opening at a given place. Such an area is for example a notch, so as not to exert pressure there. In another example, this zone is devoid of heating means, thus avoiding sticking the thermoplastic material at this location. In any case, this place corresponds to the orifice 10 to be produced on the cup.

Thus, the areas of the cup not to be sealed are protected by a reserve in the sealing device (or heat sealing device).

According to a particular embodiment, the clamps have heating elements that extend over only a portion of the total length of the clamp.

According to a particular embodiment, the apparatus has a tool which is inserted between the edges of the opening at the orifice so as to be interposed with the clamps so as to act as thermal insulation or adhesive. In this way, the orifice remains open during the manufacturing process and does not risk sticking thereafter.

Figs. 13a, 13b and 13c show various phases of the edge sticking step included in an example of a method of manufacturing a glued cup whose bottom initially has depressions and waves as illustrated in FIGS. 7a to 7c, 10 and 11. In a first step, the cup 24 is placed between the clamps 23, the cup 24 then has a curved bottom (Fig. 13a). Then, the clamps 23 are brought together to bring the two edges 421, 422 of the opening into contact with each other and to glue them together (Fig. 13b). This operation changes the curvature of the bottom which then becomes flat. Finally, when the clamps are removed (Fig. 13c), the edges remain glued and the bottom remains flat, ensuring good stability to the cup.

The method described above covers both a manual and automatic manufacturing process using industrial production equipment. Such an apparatus can take into account different heights and widths of cups, by measuring these dimensions by sensors.

According to an improvement, the apparatus sticking the edges of the opening also ensures the filling of the cup, preferably before gluing.

In another embodiment of the invention, the stability of the cup may be obtained by adding a base at the bottom of the cup, this base may be constituted for example by adding cardboard shaped waves.

Moreover, the shapes and dimensions of the straw described above are given only as examples. Other straw systems well known to those skilled in the art can be applied to the invention, the principle of the invention to make the inside of this straw not heat sealable.

In an alternative embodiment, the upper edges of the cup each comprise a sealing flange. These edges are rolled as on the traditional cups (or simply folded / folded) so as to form an extra thickness at the opening only and create at this location a reserve area.

The flange is formed by rolling the blank from the outside to the inside, firstly to block the liquid, and secondly to be heat-sealed (since the outer layer is heat-sealable).

The collar is used to tighten the edges at the opening of so that when the edges are pinched, those that need to be sealed are, and those that do not need to be squeezed against each other (without being glued), which creates a clogging.

This extra thickness is effective in particular to prevent the liquid from flowing when the cup is reversed.

This feature has two advantages:

a) it contributes to a better sealing of the cup in its unsealed part;

(b) it may constitute the reserve area that prevents sealing:

- non-heat-sealable zone in the case of cups whose outer face is not covered with thermoplastic material,

- unsized area in the case of the glue version (the glued surface is the inside of the cup).

When the two edges 421, 421 are brought together to be partially sealed on the sealable zone, the collar has the effect of bringing these unsealed edges further towards the non-sealable zone intended to allow the flow of the liquid contained in the cup, and to perfect the tightness of this "open" zone.

In the embodiment of FIGS. 14a to 14c in which the cup has no notch, there are two small projections 51 (visible in FIG. 14a) on either side of the cup extending the upper edges of the cup. The edge of the cup is turned back on itself a few millimeters (the equivalent of the height of the advance 51) and a width of a few centimeters (Figure 14b). Thus the two advances are found face to face and do not adhere during sealing (top view of Figure 14c), except in the case where a thermoplastic film is implemented on the outer face of the sidewall).

In the embodiments described above, it is provided a reserve area that prevents sealing. This non-sealable reserve zone corresponds to:

1- to a recess: the notch 6 facing the advance 7 (Figures la to le);

2- an absence of glue on part of the circumference of the opening (Figures 4a to 4c);

3- at a rupture zone on the clamps (FIG. 12b);

4- inside non-sealable straw (Figures 5 and 6);

5- to a non-thermoplastic zone when the thermoplastic layer is absent or removed from the surface intended to become the inner wall of the straw.

Furthermore, the cardboard side may be covered with thermoplastic material on all or part of its inner surface.

The inside of the paper cups may not be heat sealable. In this case, it can be expected to add a heat-sealable material only on the high edge.

Claims

A method of manufacturing a cup for containing liquid having a circular-shaped bottom and a sidewall (1) in the form of a sheet having two opposite sides (2), the method comprising a step of winding on itself the sheet so as to make a truncated cone, and seal the side of the flank (1) said "lower" (41) at the periphery of the bottom so as to give the cup a volume with an opening in upper part, said opening being delimited by two edges (421, 422) facing each other and located on the so-called "upper" side (42) of the sidewall (1), the method being characterized in that it comprises a bonding step both edges (421, 422) of the opening being pinched to bring them into contact without bending them, the gluing being effected over at least part of the opening so as to leave an open orifice allowing a liquid contained in the volume to flow.

Method for manufacturing a cup according to claim 1, characterized in that the upper side (42) of the sidewall (1) intended to form the opening is covered with an adhesive over a length less than a circumference of the opening leaving an uncoated length, sealing the edges (421, 422) of the opening of contacting the coated surfaces.

A method of manufacturing a cup according to claim 1, characterized in that the sheet constituting the sidewall (1) is covered at least in the upper part on at least one side of a thermoplastic material which is heat-welded.

Method of manufacturing a cup according to any one of the preceding claims, characterized in that the two edges (421, 422) facing each other and located on the "upper" side (42) of the sidewall (1) each comprise an extra thickness at the opening intended to prevent the liquid contained in the cup from flowing out when last is reversed.

Method for producing a cup according to any one of the preceding claims, characterized in that the lower side

(41) of the sheet forming the sidewall (1) has a curved line having at least three points of inflection.

A method of manufacturing a cup according to any one of the preceding claims, characterized in that the inner surface of the sidewall (1) of the cup comprises a bead (25) extending under the sealing strip (3), the bead (25) present on an edge of the opening coming into contact with the bead (25) present on the other edge during the sealing step.

Method for manufacturing a cup according to any one of the preceding claims, characterized in that near the orifice, the opening has a notch (6) at one edge and a projection (7) at opposite edge level.

A method of manufacturing a cup according to claim 7, characterized in that the cup has lines of weakness (8) on the flank (1) matching the shape of the notch (6) and the advanced

(7).

A method of manufacturing a cup according to any one of the preceding claims, characterized in that the step of pinching the edges (421, 422) is carried out using an apparatus having at least two tongs (16) moving towards each other at the edges of the opening, at least one clamp (16) having a break zone (17) not permitting bonding on the edge portion of the the opening forming the orifice. A method of manufacturing a cup according to any one of the preceding claims, characterized in that the cup has lines of weakness in the upper part of the sidewall (1), the lines being vertical and facing each other when the cup is formed to the outcome of the gluing step.

A method of manufacturing a cup according to any one of the preceding claims, characterized in that a lateral side said "first" sidewall (1) is glued to the opposite side side said "second" of the sidewall during the step of winding to give the cup a volume, the method further comprising a step of winding on itself the first lateral side to form a pipe (11) whose inner surface is formed by a portion of the outer surface of the flank (1), and a step of bonding the outer face of the pipe (11) thus formed to the inner surface of the second lateral side, the outlet of the pipe (11) forming the orifice following the bonding step both edges of the opening.

A method of manufacturing a cup according to claims 3 and 11, characterized in that the thermoplastic material is removed or absent from the surface intended to become the inner wall of the pipe (11).

Cup intended to contain liquid, characterized in that it is produced according to the method described by any one of claims 1 to 12.

Device for manufacturing a cup according to the process described according to any one of claims 1 to 12, characterized in that said device has two clamps (16) movable towards each other moving at the height of the edge of the opening.

Device for manufacturing a cup according to claim 14, characterized in that at least one clamp (16) comprises a zone of rupture of continuity (17) avoiding bonding on the part of the edge of the opening forming the open orifice.

Device for manufacturing a cup according to claim 14 or 15, characterized in that it comprises a tool having a role of thermal or adhesive insulator, being inserted between the edges of the opening at the orifice .