Method for heat-sealing a seal on a plastic container

Abstract

The invention relates to a method for heat-sealing a seal on a thermoplastic glass comprising a wall whose upper end comprises an edge - or rim (20) - comprising an annular rib (23) and two collection surfaces (26, 28) extending on either side of the annular rib (23). According to the invention, the rim also comprises first and second annular grooves (30, 31) extending between the annular rib (23) and the collection surfaces (26, 28). The method comprises, during the heat-sealing of the seal (50), a step consisting in causing all or part of the annular rib (23) to flow into the grooves.

Description

[0001] METHOD FOR HEAT SEALING A COVER ON A PLASTIC CONTAINER

[0002] TECHNICAL FIELD

[0003] The present invention relates to a method for heat-sealing a lid on a thermoplastic container and a thermoplastic container for implementing this method. The container has an edge - or lip - allowing the lid to be heat-sealed. The lip comprises an annular rib and two collection surfaces extending on either side of the annular rib and set back from it.

[0004] STATE OF THE ART

[0005] Figure 1 shows an example of the general shape of a container taking the form of a thermoplastic glass 1. The glass comprises a rim 10 forming the upper part of the glass on which the lips rest. Figure 2 shows, in a sectional view, a profile of the rim 10 as described by patent EP 2408 688. The rim 10 comprises an annular rib 13 and two collecting surfaces 16, 18 extending on either side of the annular rib 13. The annular rib 13 comprises a central upper part 14 and two lateral lower parts 15, 17 extending back from the central part 14 and above the collecting surfaces 16, 18. The upper part 14 and the lower lateral parts 15, 17 of the rib 13, as well as the collection surfaces 17, 18 extend in substantially parallel planes and have a general symmetry of revolution along a vertical longitudinal axis AA' of the glass.

[0006] The heat sealing of a cover 50 on the glass 1 is carried out by means of a metal heating head 60 applied to the cover 50 and exerting pressure on the rim 10, as shown in FIG. 4A. During a first step illustrated in this figure, the central upper part 14 of the rib 13 begins to melt under the effect of the heat and the pressure exerted by the heating head 60. It flows and spreads over the lower lateral parts 15, 17 of the rib, the assembly then forming a bead 140 in which the central upper part 14 and the lower lateral parts 15, 17 of the rib 13 are no longer distinguishable.

[0007] If the heat sealing process is stopped at this point, the melting of the central upper portion 14 ensures a minimal, although imperfect, seal of the lid. For this reason, the central upper portion 14 is called "fusible": it guarantees that the lid will be sealed from the first moments of the sealing process. However, to obtain a perfect seal, the process must be continued up to a stage shown in Figure 4B, in which the bead 140 has continued to flow and spreads at least partially over the collection surfaces 17, 18.

[0008] Once this stage has been reached, it is preferable not to continue the sealing process, otherwise, after having spread over the collection surfaces 16, 18, the bead 140 overflows beyond these, forming a burr which can be sharp, which extends on a horizontal plane, inside and outside the glass.

[0009] In other words, the creep process must extend beyond a minimum time Tminl where only the fuse 14 has melted, without exceeding a maximum time Tmax beyond which the rib 13 has excessively crept and forms a sharp burr. These times Tminl and Tmax depend on various parameters and more particularly on the pressure and temperature applied to the seal, as well as on the time of the heat sealing process and the pressure in the glass, which tends to increase with temperature and can cause leaks in the seal.

[0010] The applicant has years of experience in developing this heat-sealing process on an industrial scale and has observed, in certain cases, the appearance of a sharp burr despite the fact that the time Tmax has not been exceeded. Studies have shown that under certain conditions, the bead 140, before reaching the final state shown in FIG. 4B, passes through an intermediate state shown schematically in FIG. 5, in which it has two projecting ends 141, 142 oriented towards the inside and the outside of the glass. These ends are intended to disappear and spread out over the collection surfaces 16, 18. However, if the creep process is stopped too early, the ends 141, 142 remain and may be sharp, although not protruding on either side of the rim. As a result, when the user removes the seal, they can cut their lips or even their fingers.To eliminate this risk, the creep process must be continued for a minimum time Tmin2 greater than Tminl beyond which the protruding ends 141, 142 disappear, always without exceeding the time Tmax. This constraint reduces the margin of maneuver to obtain a perfect seal, which is defined by the time interval Tmin2-Tmax. This time interval can be very short in practice, of the order of a few tenths of a second to one second. Due to the tolerances on the process parameters, it can be difficult to ensure that in all circumstances, the sealing process is stopped at the appropriate time corresponding to a non-protruding bead shape as shown in Figure 4B.

[0011] To increase this margin of maneuver and more easily overcome errors related to the tolerances of the sealing process, it is possible to increase the time interval between Tmin2 and Tmax by slowing down the melting and flow of the rim. To this end, for example, a layer of silicone can be placed between the heating head and the seal to slow down the heat transfer to the rim. However, this solution has the disadvantage of requiring a higher temperature of the heating head than would be necessary in the absence of the silicone layer.

[0012] It might therefore be desirable to do away with this silicone layer for better temperature transfer, energy savings thanks to a lower heating head temperature, and a reduction in the cost of heat sealing due to the fact that the silicone layer is a consumable that must often be replaced.

[0013] More generally, it might be desirable to improve the lid sealing process just described to avoid the risk of the appearance of the aforementioned protruding ends.

[0014] STATEMENT OF THE INVENTION

[0015] To this end, the present invention provides a thermoplastic container comprising a wall whose upper end has an edge - or lip - comprising on the one hand an annular rib comprising a central upper surface (24), a first lateral surface (25) and a second lateral surface (27) and on the other hand two collection surfaces extending on either side of the annular rib, in which the lip also comprises first and second annular grooves extending between the annular rib and the collection surfaces and set back from the collection surfaces, so that all or part of the annular rib flows into the annular grooves when a lid is heat-sealed on the lip.

[0016] According to one embodiment, the first side surface and the second side surface of the annular rib extend back from the central upper surface and above the collection surfaces.

[0017] According to one embodiment, the first lateral surface of the annular rib is located on the outside of the container, the second lateral surface of the annular rib is located on the inside of the container and has a radial width greater than that of the first lateral surface of the annular rib.

[0018] According to one embodiment, the first annular groove is located on the outside of the container, the second annular groove is located on the inside of the container and has a radial width greater than that of the first annular groove.

[0019] According to one embodiment, the first collection surface is located on the outside of the container, the second collection surface is located on the inside of the container and has a radial width greater than that of the first collection surface.

[0020] According to one embodiment, the collection surfaces and the central upper surface of the annular rib are of substantially rounded shape.

[0021] According to one embodiment, the rim has a radial width of between 2 and 4 millimeters.

[0022] According to one embodiment, the annular grooves have a depth of the order of one tenth of a millimeter to five tenths of a millimeter relative to the collection surfaces, and a radial width of the order of one tenth of a millimeter to five tenths of a millimeter.

[0023] Embodiments of the invention also relate to a method for heat-sealing a lid on the rim of a thermoplastic container, the rim comprising on the one hand an annular rib having a central upper surface (24), a first lateral surface (25) and a second lateral surface (27), and on the other hand two collection surfaces extending on either side of the annular rib, in which the rim also comprises first and second annular grooves extending between the annular rib and the collection surfaces and set back from the collection surfaces, the method comprising, during heat-sealing of the lid, a step consisting of causing all or part of the annular rib to flow into the grooves.

[0024] According to one embodiment, the first side surface and the second side surface of the annular rib extend back from the central upper surface and above the collection surfaces.

[0025] According to one embodiment, the first lateral surface of the annular rib is located on the outside of the container, the second lateral surface of the annular rib is located on the inside of the container and has a radial width greater than that of the first lateral surface of the annular rib.

[0026] According to one embodiment, the first annular groove is located on the outside of the container, the second annular groove is located on the inside of the container and has a radial width greater than that of the first annular groove.

[0027] According to one embodiment, the first collection surface is located on the outside of the container, the second collection surface is located on the inside of the container and has a radial width greater than that of the first collection surface.

[0028] According to one embodiment, the rim has a radial width of between 2 and 4 millimeters, the annular grooves have a depth of the order of one tenth of a millimeter to five tenths of a millimeter relative to the collection surfaces, and a radial width of the order of one tenth of a millimeter to five tenths of a millimeter.

[0029] Embodiments of the invention also relate to a method of manufacturing a thermoplastic wine glass containing wine and sealed by a seal, the method comprising a step of manufacturing the glass, a step of filling the glass with wine, and a step of heat-sealing the seal on the rim of the glass according to the method of the invention described above.

[0030] BRIEF DESCRIPTION OF THE FIGURES Examples of embodiments of a container having the shape of a glass and of a heat-sealing method according to the invention will be described in the following without limitation in relation to the attached figures, among which:

[0031] - figure 1 previously described shows a glass made of thermoplastic material comprising a rim having a classic profile,

[0032] - Figure 2 previously described shows the profile of the glass drinker,

[0033] - figure 3 shows dimensions of the drinking profile,

[0034] - figures 4A, 4B previously described show an initial step and a final step of a conventional method of sealing a lid on the rim,

[0035] - Figure 5 previously described shows an intermediate step of the classic sealing process,

[0036] - figure 6 shows a glass made of thermoplastic material comprising a rim according to one embodiment of the invention,

[0037] - figure 7 is a top view of the drinking mouth of figure 6,

[0038] - figure 8 is a sectional view of the rim of figure 6,

[0039] - figure 9 shows a cover intended to be sealed on the rim of figure 6,

[0040] - figure 10 shows dimensions of the profile of the drinking edge of figure 6,

[0041] - figure 11 shows an initial step of a method of sealing according to the invention the cover on the rim of figure 6,

[0042] - figure 12 shows an intermediate step of the sealing method according to the invention,

[0043] - figure 13 shows another intermediate step of the sealing method according to the invention,

[0044] - figure 14 shows a final step of the sealing method according to the invention, and

[0045] - Figure 15 is the flowchart of a method of manufacturing a sealed wine glass according to the sealing method of the invention.

[0046] DETAILED DESCRIPTION

[0047] Figure 6 shows a thermoplastic glass 100 comprising a rim 20 according to the invention. Figure 7 is a top view of the rim 20 and Figure 8 is a sectional view of the rim 20. In Figure 7, the rim has a diameter D which is not to scale for reasons of readability of this figure. This diameter D is in practice of the order of a few centimeters, while the radial width L of the rim is of the order of a few millimeters.

[0048] With reference to Figure 8, the rim 20 comprises an inner face 21 corresponding to the inner face of the chimney of the glass 100, and an outer face 22 extending projecting relative to the outer face of the chimney, forming a projecting annular collar. This collar 22 can serve as a support to receive the end of a gripping tool, to facilitate the handling of the glass or its blank during its manufacture. This manufacture is preferably carried out by injection-blow molding, and comprises a step of injecting a thermoplastic polymer, in particular polyethylene terephthalate (PET), into a mold to obtain a blank, then a step of blowing the blank to obtain the glass 100.

[0049] According to the invention, the rim 20 comprises an annular rib 23 bordered by two annular collection grooves 30, 31 provided on either side of the rib 23. The groove 30 - or outer groove - is arranged on the outside of the glass 100, while the groove 31 - or inner groove - is arranged on the inside of the glass 100.

[0050] The rim also comprises, on either side of the grooves 30, 31, two annular collection surfaces 26, 28 which border the grooves 30, 31. The surface 26 - or outer collection surface - runs along the outer groove 30 while the surface 28 - or inner collection surface - runs along the inner groove 31.

[0051] In one embodiment, the rib 23 comprises in a conventional manner a central upper portion 24 and two lateral lower portions 25, 27 extending back from the central portion 24 and above the grooves 30, 31 and collecting surfaces 26, 28. The surfaces of the lateral lower portions 25, 27 of the rib 23 will be referred to hereinafter as "lower lateral surfaces" 25, 27 of the rib 23. The surface of the upper portion 24 will be referred to hereinafter as the "central upper surface" 24 of the rib 23. The collecting surfaces 26, 28 as well as the lower lateral surfaces 25, 27 and the upper surface 24 of the rib 23, have a general symmetry of revolution along the vertical longitudinal axis AA' of the glass 100 (Fig. 6).The collecting surfaces 26, 28, the lower side surfaces 25, 27 of the rib 23, as well as the upper surface 24 of the rib 23, are ideally substantially flat and will be considered as such in the following, for the sake of simplicity. However, due to the injection-blow manufacturing process, some of these surfaces may in practice be substantially rounded as seen in Figures 8, 10, 12 to 14. The method of the invention and the advantages it provides are, in any event, not dependent on the flat or rounded shape of these surfaces.

[0052] Figure 10 shows the profile 200 of the rim 20 and the arrangement of the surfaces 24 to 28, 30, 31 in planes substantially parallel and perpendicular to the vertical longitudinal axis AA' of the glass (considering that these surfaces are substantially flat). The collecting surfaces 26, 28 extend in a plane PO, the lateral surfaces 25, 27 of the rib 23 extend in a plane P1, and the upper surface 24 of the rib 23 extends in a plane P2. The plane P1 extends above the plane PO and at a height h10 above it. The plane P2 extends above the plane P1 and at a height h20 above it. The bottom of the grooves 30, 31 extends in a plane G0 located below the plane PO and at a depth g10 below it.The difference in height dh between the bottom of the grooves 30, 31 (plane G0) and the lower lateral surfaces 25, 27 of the rib (plane P1) is here equal to the sum of the height h10 and the depth g10, while the difference in height between the bottom of the grooves 30, 31 (plane G0) and the collection surfaces 25, 27 (plane PO) is equal to the height h10. In one embodiment, the heights h10, h20 and the depth g10 are of the order of one tenth of a millimeter to five tenths of a millimeter.

[0053] Figure 9 is a top view of a cover 50 intended to be heat-sealed on the rim 20, the sealing being carried out in a zone 55 of the ring-shaped cover corresponding to the location of the rim. Figure 11 shows the positioning of a heating head 60 above the rim 20 with the interposition of the cover 50. The cover may comprise a central metallic layer 51, for example an aluminum layer with a thickness of the order of 30 to 60 micrometers. The upper face of the layer 51, located opposite the heating head 60, may be coated with a layer 52 such as a lacquer or a plastic film, for example a polyester film. The lower face of the layer 51, located opposite the rim 20, may be coated with a layer 53 such as a heat-sealing lacquer.

[0054] Figures 12, 13 and 14 show steps of the heat sealing method according to the invention. For the sake of readability of these figures, the heating head and the seal are not shown.

[0055] During a first step illustrated in Figure 12, the central upper part 24 of the rib 23 begins to melt under the effect of the heat and pressure exerted by the heating head. It flows and spreads over the lateral surfaces 25, 27 of the rib, the assembly then forming a bead 240 in which the central upper part 14 and the lateral surfaces 25, 27 are no longer distinguishable.

[0056] During a step illustrated in FIG. 13, the bead 240, under the effect of the pressure, continues to flow and spread towards the collection surfaces 26, 28, forming two ends 241, 242 oriented towards the inside and the outside of the glass, which extend above the collection grooves 30, 31.

[0057] During a step illustrated in Figure 14, the bead 240 has been completely flattened under the effect of the pressure exerted by the heating head and the ends 241, 242, the volume of which has increased under the effect of the flow of the material of the bead, have lodged in the collection grooves 30, 31. At this time, the top of the bead has a very low height relative to the collection surfaces 26, 28. If the sealing process is continued for a longer time, a very small quantity of the material of the bead 240 may possibly flow onto the collection surfaces 26, 28, but in insufficient quantity to extend beyond the rim and form a cutting burr. Thus, the collection grooves 30, 31 according to the invention constitute a receiving volume preventing the bead 240 from reaching the collection surfaces 26, 28 during its creep, and at the very least preventing the majority of the material forming the bead from reaching the collection surfaces 26, 28.It goes without saying that the process cannot be continued inconsiderately, because beyond a certain time the entire surface of the rim could flow, causing the appearance of sharp burrs. The sealing process can therefore be continued until the ends 241, 242 are received by the collection grooves, thus eliminating the risk of these forming sharp edges as in the previous method (Fig. 5, ends 141, 142) and delaying the moment when excessive creep would cause the thermoplastic material to overflow beyond the rim 20.

[0058] Tables 1 and 2 below provide, without limitation, examples of dimensioning expressed in millimeters of the different parts of the profile 200 of the rim 20 as shown in Figure 10. For comparison, these tables also provide examples of dimensioning of a conventional rim profile 10 as shown in Figure 3.

[0059] In Figure 10, the references L24, L25, L27 designate the radial widths of the different surfaces 24, 25, 27 of the rib 23. The references L30 and L31 designate the radial widths of the collection grooves 30 and 31. The references L26 and L28 designate the radial widths of the collection surfaces 26 and 28. As indicated above, the reference h10 designates the difference in height between the lower lateral surfaces 25, 27 of the rib 23 and the collection surfaces 26, 28. The reference h20 designates the difference in height between the upper surface 24 of the rib 23 and its lower lateral surfaces 25, 27. The reference g10 designates the depth of the collection grooves 30, 31. The reference dh designates the difference in height between the bottom of the grooves 30, 31 and the lower lateral surfaces 25, 27 of the rib 23.

[0060] In Figure 3, the references L16 and L18 designate the radial widths of the collection surfaces 16 and 18. The references L15 and L17 designate the radial widths of the lower lateral parts 15 and 17 of the rib 13. The reference L14 designates the radial width of the central upper part 14 of the rib 13. The reference h1 designates the difference in height between the surfaces of the lower lateral parts 15, 17 and the collection surfaces 16, 18. The reference h2 designates the difference in height between the central upper part 14 and the surfaces of the lower lateral parts 15, 17 of the rib 13.

[0061] Comparison of the exemplary and non-limiting dimensions shown in Table 1 shows that for a constant radial width of the rim equal here to 2.7 millimeters, the location of the grooves 30, 31 is found by reducing the radial widths L25, L27 of the lateral surfaces 25, 27 of the rib 23 and / or by reducing the radial widths L26, L28 of the collecting surfaces 26, 28. Furthermore, according to a design rule which emerges from Table 1 and combines with the previous one, the radial width L27 of the lower lateral surface 27 of the rib 23, which is located on the side of the inner face of the rim, is greater than the radial width L25 of the lower lateral surface 25 of the rib 23, which is located on the side of the outer inner face of the rim. This inequality of widths makes it possible to compensate for the difference in the average diameter of these surfaces so that their respective total surfaces are approximately equal.For the same reason, the radial width L28 of the collection surface 28, which is located on the side of the inner face of the rim, is greater than the radial width L26 of the collection surface 26, which is located on the side of the outer face of the rim. In one embodiment, the collection grooves 30, 31 may also have different radial widths, so that their respective collection volumes are substantially identical.

[0062] [Table 1]

[0063] Finally, the comparison of the exemplary and non-limiting dimensions appearing in Table 2 shows that the difference in height dh between the bottom of the grooves and lower lateral surfaces 25, 27 of the rib 23 is equal to the difference in height h1 between the surfaces of the lower lateral parts 15, 17 and the collection surfaces 16, 18 of the rim profile 10 according to the prior art. Thus, the thermoplastic material sees substantially the same difference in level when it flows towards the internal and external edges of the rim. As a result, the collection surfaces 26, 28 of the rim profile 200 of the invention form more barriers against the flow of the thermoplastic material beyond the collection grooves 30, 31, than collection surfaces strictly speaking, the term "collection surface" having been retained in the present description only by analogy with the prior art. [Table 2]

[0064] The method according to the invention offers, compared to the method of the prior art, various other advantages. In particular, it allows the sealing process to be carried out without coating the heating head with a layer of silicone, and therefore improves the heat transfer in the rim. The temperature of the heating head can be lowered and brought, for example, to around 180-190°C instead of 220-230°C, thereby saving energy. The duration of the sealing process can be reduced to around 1.8 to 2 seconds instead of 2.4 seconds, resulting in improved manufacturing yields and additional energy savings by reducing the heating time.As a further advantage, the reduction in heat sealing time allows to reduce the expansion in the glass of the mixture of neutral gases in the presence of which the sealing is carried out, for example a mixture of carbon dioxide (CO2), Nitrogen and Argon, and therefore to eliminate the risks of seal leaks linked to excessive expansion of the gas.

[0065] The method of the invention can also be implemented and offers the same advantages by using a non-heating heat-sealing head and heating the seal by induction, in the presence of a magnetic field which excites the metal atoms and causes them to heat up. In this case, the heat-sealing head only ensures the application of the heat-sealing pressure, while the heat is generated in situ in the seal.

[0066] The method of the invention is particularly suitable for industrial-scale production of heat-sealed thermoplastic wine glasses containing wine. Such an industrial manufacturing method for glasses containing wine is illustrated in Figure 15. This method comprises a step S01 of manufacturing the glass 100, a step S02 of filling the glass with wine, and a step S03 of heat-sealing according to the invention. These steps are followed by a step S04 of packaging and then transport to places of sale or distribution. As indicated above, the manufacturing step S01 is preferably carried out by injection-blow molding, and comprises a step of injecting a thermoplastic polymer, in particular polyethylene terephthalate (PET), into a mold to obtain a blank, then a step of blowing the blank to obtain the glass.The heat sealing step is carried out in a controlled atmosphere comprising neutral gases, for example a mixture of carbon dioxide (CO2), Nitrogen and Argon.

[0067] It will be clear to those skilled in the art that the present invention is susceptible to various variants, in particular with regard to the shape, arrangement and relative positions of the different surfaces of the annular rib and the collection surfaces, and is also susceptible to various applications. In one variant, the rib 23 may further comprise shallow grooves making it possible to reduce the quantity of material it contains and thus further reduce the heat-sealing time.

[0068] In other applications, the method may be used to seal a lid on a container other than a glass, containing wine or another type of liquid. Thus, the term "glass" in the present application is not limiting and relates to a container containing a liquid.

Claims

DEMANDS 1. Container (100) made of thermoplastic material comprising a wall having an upper end with an edge - or rim (20) - comprising on the one hand an annular rib (23) having a central upper surface (24), a first lateral surface (25) and a second lateral surface (27), and on the other hand two collection surfaces (26, 28) extending on either side of the annular rib (23), characterized in that the rim also comprises first and second annular grooves (30, 31) extending between the annular rib (23) and the collection surfaces (26, 28) and set back from the collection surfaces (26, 28), so that all or part of the annular rib (23) flows into the annular grooves (30, 31) when a lid (50) is heat-sealed on the rim.

2. Container according to claim 1, in which the first lateral surface (25) and the second lateral surface (27) of the annular rib (23) extend back from the central upper surface and over the collection surfaces (26, 28).

3. Container according to claim 2, wherein the first lateral surface (25) of the annular rib (23) is located on the outside side of the container, the second lateral surface (27) of the annular rib (23) is located on the inside side of the container and has a radial width greater than that of the first lateral surface (25) of the annular rib (23).

4. Container according to any one of claims 1 to 3 wherein the first annular groove (30) is located on the outside side of the container, the second annular groove (31) is located on the inside side of the container and has a radial width greater than that of the first annular groove (30).

5. Container according to any one of claims 1 to 4, wherein the first collection surface (26) is located on the outside side of the container, the second collection surface (28) is located on the inside side of the container and has a radial width greater than that of the first collection surface (26).

6. Container according to claim 2, in which the collection surfaces (26, 28) and the central upper surface (24) of the annular rib (23) are substantially rounded in shape.

7. Container according to any one of claims 1 to 6, wherein the drinking spout (20) has a radial width of between 2 and 4 millimeters.

8. Container according to any one of claims 1 to 7, in which the annular grooves (30, 31) have a depth of the order of one tenth of a millimeter to five tenths of a millimeter relative to the collection surfaces (26, 28), and a radial width of the order of one tenth of a millimeter to five tenths of a millimeter.

9. A heat-sealing process for a lid (50) on the rim (20) of a thermoplastic container, the rim comprising on the one hand an annular rib (23) having a central upper surface (24), a first lateral surface (25) and a second lateral surface (27) and on the other hand two collection surfaces (26, 28) extending on either side of the annular rib (23), characterized in that the rim also comprises first and second annular grooves (30, 31) extending between the annular rib (23) and the collection surfaces (26, 28) and set back from the collection surfaces (26, 28), and in that it comprises, during the heat-sealing of the lid (50), a step consisting of making all or part of the annular rib (23) flow into the grooves.

10. Method according to claim 9, wherein the first lateral surface (25) and the second lateral surface (27) of the annular rib (23) extend back from the central upper surface and above the collection surfaces (26, 28).

11. Method according to claim 10, wherein the first lateral surface (25) of the annular rib (23) is located on the outside side of the container, the second lateral surface (27) of the annular rib (23) is located on the inside side of the container and has a radial width greater than that of the first lateral surface (25) of the annular rib (23).

12. A method according to any one of claims 9 to 11 wherein the first annular groove (30) is located on the outside side of the container, the second annular groove (31) is located on the inside side of the container and has a radial width greater than that of the first annular groove (30).

13. A method according to any one of claims 9 to 12, wherein the first collection surface (26) is located on the outside of the container, and the second collection surface (28) is located on the inside of the container and has a radial width greater than that of the first collection surface (26).

14. A method according to any one of claims 9 to 13, wherein the drinking spout (20) has a radial width of between 2 and 4 millimeters, the annular grooves (30, 31) have a depth of the order of one tenth of a millimeter to five tenths of a millimeter relative to the collection surfaces (26, 28), and a radial width of the order of one tenth of a millimeter to five tenths of a millimeter.

15. A method for manufacturing a thermoplastic wine glass (100) containing wine and sealed by a lid (50), comprising: - a step (S01) in glass manufacturing, - a step (SO2) of filling the glass with wine, and - a heat-sealing step (S03) of the lid (50) on the rim (20) of the glass according to the process according to one of claims 9 to 14.

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