Metal packaging with twist-off capsule

Abstract

The invention relates to a packaging body (3) comprising an end (31) forming a ring having an edge (33) defining an opening for accessing the interior of the body (3), which edge is referred to as the opening edge, the ring (31) having threads (311) intended to threadedly engage with a twist-off capsule provided with a seal, said seal being intended to engage with the opening edge (33) of the ring (31) in order to hermetically close the body (3) in a way that withstands heat sterilisation, the packaging body characterised in that it is made of metal.

Description

Metal packaging with twist-off cap

[0001] The invention relates to packaging for storing and preserving products, particularly food, by pasteurization and heat sterilization. More specifically, it relates to twist-off packaging.

[0002] The twist-off cap is a metal cap with lugs. There can be 3 lugs (for a 27 mm diameter cap) to 8 (for a 110 mm diameter cap). The complementary packaging body has as many threads on its ring as there are lugs on the cap, and each thread cooperates with a lug to ensure the closure or opening of the packaging body by the cap. Twist-off caps (also called "lug caps" in English) require less than one turn of the ring to close and open (around 1 / 8 to 1 / 3 of a turn depending on the diameter). They each extend over 1 / 8 to 1 / 3 of the circumference of the ring. Thus, each thread extends over less than one turn of the ring (from 1 / 8 to 1 / 3 of the turn of the ring). The threads are distributed around the ring and are adjacent in pairs. They form a discontinuous thread, as opposed to the continuous thread which serves as a guide for the continuous thread of a screw cap.

[0003] Twist-off packaging traditionally features a glass body, which includes a ring designed to cooperate with a twist-off cap.

[0004] To ensure a tight seal, from sterilization to opening of the packaging body, the capsule has a groove in which a seal is housed. This ensures a seal by compression on the upper edge of the ring.

[0005] Twist-off capsules are for example named as follows:

[0006] RTO (Regular Twist Off), RTB (Regular Twist Off with Safety Button), RTS (Twist Off with Step), RTB (Twist off with Step and Safety Button), RTA (Twist Off with Angle), RAB (Twist Off with Angle and Safety Button), DTO (Depp Twist Off), DTB (Deep Twist Off with Safety Button), MTO (Medium Twist Off), MTB (Medium Twist Off with Safety Button).

[0007] The metal lids of glass jars are made of pasteurizable and sterilizable materials that can withstand high temperatures and are kept closed by atmospheric pressure. Glass-metal contact is therefore currently controlled with regard to temperature and pressure variations.

[0008] To break the seal and open the packaging body, the cap is unscrewed. After this first opening, the packaging body can be closed again by screwing the cap back on, and opened again by unscrewing it.

[0009] These twist-off packaging bodies have good sealing performance and resistance to mechanical stress during sterilization or pasteurization phases, and are widely used for food preservation. However, glass twist-off packaging bodies are fragile and can be easily broken.

[0010] Packaging bodies are known which are closed by capsules other than twist-off capsules. Thus, in document DE4421523, the hermetic closure is obtained by means of a locking cord present on the internal face of the packaging body, and which allows the locking of an engagement lip of the capsule.

[0011] Furthermore, less fragile metal packaging bodies are known. However, these packaging bodies are hermetically sealed by crimped lids. Indeed, the skilled person considers that only the crimping of two metal surfaces in contact ensures a tight closure during the sterilization phase. This is due to the fact that, during the sterilization process, the box is subjected to drastic thermal and pressure stresses: up to 131°C for 1 hour with internal and / or external overpressures of up to 1.2 bar during the cycle. The internal pressure increases with the temperature and this increase could lead to irreversible deformation and could lead to a rupture of the seal.

[0012] Metal packaging bodies are also known that are designed to cooperate with a cap by screwing. However, these packages do not cooperate with a twist-off cap.

[0013] This is the case in document DE202018105977. Furthermore, in this document, the packaging body is not used for heat sterilization.

[0014] GB2325924 also describes a metal packaging body. The access opening of this packaging body is provided with a collar intended to cooperate with a membrane allowing the packaging body to be closed. This packaging body does not cooperate with a twist-off cap.

[0015] GB2545672 describes a packaging body that is quite different from a twist-off packaging body. Unlike a twist-off packaging body, this packaging body does not have an opening edge that cooperates with a seal. In this document, the seal cooperates with the side surface of the packaging body. Furthermore, in this document, the packaging body is not used for heat sterilization.

[0016] The invention aims in particular to provide twist-off packaging bodies having improved mechanical resistance to stresses and impacts.

[0017] To this end, the invention relates to a packaging body comprising an end forming a ring comprising an edge, delimiting an access opening to the interior of the body, called the opening edge, the ring comprising threads intended to cooperate by screwing with a twist-off cap equipped with a seal. This seal is intended to cooperate with the opening edge of the ring for a hermetic closure of the body resistant to heat sterilization. The packaging body is made of metal.

[0018] Thus, it is proposed to provide a metallic twist-off packaging body. This goes against the prejudice of the person skilled in the art concerning the behavior of two metallic materials in contact and the phenomena of metal-metal interaction under the effect of variations in internal and external pressures.

[0019] The packaging body according to the invention has the usual advantages of twist-off packaging bodies, namely good resistance to mechanical stresses during the sterilization and pasteurization phases, good sealing and impermeability to gases, good compatibility with the majority of products, and in particular solvents, stability of the materials which allows good preservation of the product and preserves its organoleptic qualities, easy and economically very acceptable recycling, good thermal conductivity, excellent resistance to internal pressure and good resistance to ionizing radiation. It is also easy to print on this metal packaging. Finally, the metal packaging body has good stacking strength and good stacking resistance.

[0020] It also has high mechanical resistance to stress and shocks and protects the contents from solar radiation. Also, the use of metal, which is easier to implement and transport than glass, has advantages, both in terms of manufacturing and the transport and storage of containers. Due to its metal composition, it is also possible to consider using magnetism, for example to hold the packaging body during capping. In addition, this packaging body allows its contents to be "hidden" from the user's eyes, which is advantageous for contents that are not attractive in appearance. The weight of metal packaging is also much lower (approximately 80% less), which improves transport options.

[0021] Compared to crimped metal cans, it is easy to open, resealable, and less risky to handle (less risk of cutting). It also has a more modern image.

[0022] Compared to other closure systems, such as the press-on turn-off system, the twist-off system can be developed for a wide variety of opening diameters (large diameters suitable for products with low hydration and small diameters for liquids). It requires less force for opening. It can be used to manufacture both two-piece cans (with a deep-drawn base) and three-piece cans (with a seamed base).

[0023] A packaging body is hermetically sealed when it is impervious to gases and liquids, and to any external contamination.

[0024] Heat sterilization is a process that involves heating the packaging body to a temperature of at least 100°C. The duration and temperature vary depending on the type of food and the packaging used, in order to prevent microorganisms from surviving and developing inside the packaging body.

[0025] A heat-resistant airtight seal withstands temperatures of at least 100°C and up to 131°C.

[0026] Preferably, the threads are helical projections, i.e., they are inclined relative to the circumferential direction.

[0027] The packaging body may include other optional features, taken alone or in combination, specified below.

[0028] - The packaging body is formed from a metal sheet whose thickness ranges from 0.15 to 0.27 mm, preferably from 0.17 to 0.25 mm, even more preferably from 0.19 to 0.23 mm, and the hardness ranges from TS260 to TH580 in accordance with standard NF EN 10202 of January 2002, preferably less than or equal to TH435, and more preferably from TS290 to TH415. Such a packaging body has improved internal pressure resistance, particularly suitable for use in heat sterilization. Furthermore, the hardness is preferably less than or equal to TH435 because a higher hardness makes it difficult to manufacture the packaging body if expansion or shrinking is required.

[0029] - There are three to eight threads, distributed along the circumference of the ring. Each thread can thus cooperate with a lug of a twist-off capsule having a number of lugs identical to the number of threads, thus ensuring the closure of the container. Advantageously, the threads are adjacent two by two.

[0030] - Each thread extends 1 / 8 to 1 / 3 of the ring circumference. Thus, less than one ring turn is required to open or close the container.

[0031] The invention also relates to a packaging comprising a packaging body as described above, and a twist-off cap intended to cooperate by screwing with the threads of the packaging body, the cap being equipped with a seal intended to cooperate with the opening edge of the ring of the body for a hermetic closure of the body resistant to heat sterilization.

[0032] The packaging may include other optional features, taken alone or in combination, specified below.

[0033] - The seal is made of a thermoplastic elastomer material, and is capable of withstanding heat sterilization. The term "thermoplastic elastomer" means a plastic material capable of plastically deforming upon heating, and of elastically deforming at room temperature. The seal according to the invention does not contain PVC (polyvinyl chloride), and is not formulated from substances containing it. The seal is said to be "capable of withstanding heat sterilization", that is to say that it will retain its sealing properties even after a sterilization process of up to 131°C. The heat sterilization temperature is at least 100°C and at most 131°C.

[0034] Such materials are described, for example, in US2015 / 0028035. The branded products PROVALIN 1241, PROVALIN 1288 and PROVALIN 1269 from ACTEGA DS GmbH (Straubinger Str. 12, Box 107701, 28219 Bremen, Germany) may be used.

[0035] Such a seal ensures an optimal airtight seal, resistant to heat sterilization. In addition, it has an optimized interaction with the opening edge of the ring of the metal packaging body, facilitating the opening of the packaging body.

[0036] - The twist-off cap comprises a panel and a skirt comprising at its outer end a rolled edge extending radially inwards, the rolled edge comprising lugs, preferably three to eight lugs distributed around the circumference of the outer end of the rolled edge, and each lug is intended to cooperate with a thread of the packaging body, by direct contact between the thread and the lug. The cap can thus be screwed onto the packaging body so as to make the seal cooperate with the opening edge of the body, thus allowing the latter to be hermetically closed.

[0037] The invention finally relates to a method for manufacturing a packaging body as described above. The manufacturing method comprises the following steps: - during a so-called "rolling" step, a free edge of a part of a ferrule, called the "capsule connection part", is rolled outwards or inwards so as to form an opening edge of the packaging body, - before or after the rolling step, threads are formed on the connection part.

[0038] A ferrule is a hollow cylindrical part of constant radius, with or without a base. A ferrule without a base can be obtained by electrically welding a metal sheet to give it a hollow cylindrical shape. Such a ferrule, without a base, can be used in the manufacturing method according to the invention.

[0039] A base can be assembled to this cylindrical part by crimping, before implementing the manufacturing process. In this case, the ferrule used in the process will have a base. Alternatively, the base can be added by crimping during a later stage of manufacturing the packaging body. A baseless ferrule makes it possible to manufacture a box in three elements (side wall of the packaging body, base of the packaging body and cap). A ferrule, with an integrated base, can also be obtained by stamping a metal sheet to give it a hollow cylindrical shape with a base. A ferrule with an integrated base makes it possible to manufacture a box in two elements (packaging body and cap).

[0040] Due to the fact that the packaging body has several fragile areas (diameter change area, threaded area), its manufacture is not easy. Such a process makes it possible to obtain a packaging body with the expected shape, for its use in heat sterilization.

[0041] The method may include other optional features, taken alone or in combination, specified below.

[0042] - First and second parts of different diameters are formed, the first part having a diameter smaller than that of the second part.

[0043] - The first part is made by swaging the ferrule. This process allows not only the manufacture of three-piece cans, but also the manufacture of two-piece cans. The first part can be obtained by one or more swaging steps. Advantageously, the rolling step is carried out after the swaging step(s). Optionally, the threads are obtained by rolling using rollers. Advantageously, the threading is carried out after the swaging and rolling steps.

[0044] - The method further comprises a step of edging outwards a free edge of the ferrule opposite the free edge of the ferrule intended to be rolled. This makes it possible, in order to obtain a three-part box, to assemble the ferrule to a base by crimping. Advantageously, the edging is carried out at the same time as the rolling step, before forming the threads. Optionally, the method further comprises a step of molding the second part of the ferrule. Advantageously, this step is subsequent to the steps of swaging, rolling, edging and threading.

[0045] - The second part is made by expanding the shell. This allows the formation of the second part and the formation of the threads to be carried out at the same time if these are made by expansion. This therefore reduces the manufacturing time of the packaging body. Optionally, the threads are obtained by rolling using rollers.

[0046] - The method further comprises a step of edging a free edge of the shell opposite the free edge of the shell intended to be rolled. This makes it possible, in order to obtain a three-part box, to assemble the shell to a base by crimping. Advantageously, the edging is carried out after the rolling and expansion steps.

[0047] - Rolling is carried out before the expansion step allowing the production of the second part. When rolling is carried out before generating a change in diameter, and forming the threads, it is possible to avoid causing a collapse of these areas which are fragile. This is therefore an improvement of the process, favoring the production of a packaging body suitable for use in heat sterilization, with a twist-off cap. Alternatively, rolling is carried out after the expansion step, if the process requires it for reasons of simplification of manufacturing. Also alternatively, flanging is carried out at the same time as rolling, before forming the threads.

[0048] - The first or second part forms the ring. Brief description of the figures

[0049] The invention will be better understood on reading the following description, given solely by way of example and with reference to the appended drawings in which:

[0050] is a perspective view of a package according to one embodiment of the invention (body and lid);

[0051] is a perspective view of the body of the ;

[0052] is a perspective view of the capsule of the ;

[0053] is a longitudinal sectional view of a portion of the packaging of the;

[0054] Figures 5a and 5b are sectional views of a ferrule illustrating different stages of formation of the packaging body according to a first embodiment of the invention;

[0055] Figures 6a, 6b and 6c are sectional views of a ferrule illustrating different stages of formation of the packaging body according to a second embodiment of the invention;

[0056] Figures 7a, 7b, 7c and 7d are sectional views of a ferrule illustrating different stages of formation of the packaging body according to a third embodiment of the invention;

[0057] Figures 8a, 8b and 8c are sectional views of a ferrule illustrating different stages of formation of the packaging body according to a fourth embodiment of the invention;

[0058] Figures 9a, 9b and 9c are sectional views of a ferrule illustrating different stages of formation of the packaging body according to a fifth embodiment of the invention. Detailed description

[0059] Figures 1 to 4 show a package according to an embodiment of the invention, designated by the general reference 1. The package 1 comprises a packaging body 3 and a twist-off capsule 5.

[0060] The packaging body 3 has an end 31 forming a ring having an edge 33, delimiting an access opening to the interior of the body 3, called the opening edge. The ring 31 has threads 311 intended to cooperate by screwing with the twist-off cap 5 which is equipped with a seal 7, visible in particular on the. On the, the thickness of the seal is not necessarily shown to scale. This seal 7 is intended to cooperate with the opening edge 33 of the ring 31 for a hermetic closure of the body 3 resistant to heat sterilization. The packaging body 3 is made of metal.

[0061] The packaging body 3 is formed from a metal sheet 35 whose thickness ranges from 0.15 to 0.27 mm, and the hardness ranges from TS260 to TH580 in accordance with standard NF EN 10202 of January 2002.

[0062] The twist-off capsule 5 comprises a panel 51 and a skirt 53 comprising at its outer end a rolled edge 531 extending radially inwards. The rolled edge 531 comprises lugs 5313. In the embodiment of FIGS. 1 to 4, the capsule 5 comprises six lugs 5313 visible in particular on the. This number of six lugs is given by way of example. There may nevertheless be more or less than six lugs. The lugs 5313 are distributed over the circumference of the outer end of the rolled edge 531, and each lug 5313 is intended to cooperate with a thread 311 of the packaging body 3, by direct contact between the thread 311 and the lug 5313, as illustrated in particular on the.

[0063] In the embodiment of Figures 1 to 4, the threads 311 of the packaging body 3 are six in number. They are distributed along the circumference of the ring 31. In this embodiment, each thread extends over 1 / 6 of the circumference of the ring. They are adjacent two by two.

[0064] The seal 7 is made of a thermoplastic elastomer material, and is capable of withstanding heat sterilization.

[0065] Figures 5a and 5b show sectional views of a ferrule 5005 illustrating different steps of forming the packaging body 5003 according to a first embodiment of the invention. The steps are shown in the order in which they are carried out.

[0066] The formation of the packaging body 5003 comprises the following steps: - during a so-called "rolling" step, shown in Figure 5a, a free edge 50053 of a part 50051 of the ferrule 5005 is rolled inwards. This part 50051 of the ferrule is called the "capsule connection part". The rolling step is carried out so as to form an opening edge 5033 of the packaging body 5003; - after the rolling step, threads 5311 are formed (Figure 5b) on the connection part 50051.

[0067] In this embodiment, a straight packaging body is produced, with a constant diameter except for the threading area. The rolling is inwards, so as to allow the cap to be screwed on.

[0068] In this embodiment, the threads are obtained by rolling using rollers.

[0069] In this embodiment, the ferrule 5005 is a ferrule with an integrated bottom. It can be obtained by stamping a metal sheet. It has a hollow cylindrical shape with a bottom.

[0070] In the variant shown in Figures 5, a 5007 molding is also produced. It is produced by rolling. The molding is optional. Its presence, creating an area of ​​larger diameter, prevents the capsules from colliding and unscrewing during handling.

[0071] The other embodiments shown include the same rolling and thread forming steps, but the rolling is done outward. In the following, only the differences from this first embodiment will be mentioned.

[0072] In the embodiment of Figures 6a to 6c, a first part 60055 and a second part 60057 are further formed, during a step prior to the rolling and thread forming steps 6311. This prior step is shown in Figure 6a. In this embodiment, the first part 60055 is made by swaging, and more specifically here, there have been several swaging steps. In this embodiment, the first part 60055 forms the ring 6031.

[0073] In the embodiment of Figures 7a to 7d, the ferrule 7005 is a ferrule without a bottom. Compared to the method shown in Figures 6a to 6c, the present method further comprises a step of edging outwards a free edge 70059 of the ferrule opposite the free edge 70053 of the ferrule intended to be rolled. This makes it possible, in order to obtain a box in three elements, to assemble the ferrule to a bottom by crimping. The edging step is shown in Figure 7b. In this embodiment, the edging is carried out at the same time as the rolling step, before forming the threads 7311. This embodiment further comprises a step of molding the second part 70057 of the ferrule, shown in Figure 7d. This molding step is optional. In this embodiment, the subsequent crimping step is not shown. The packaging body is therefore not shown.

[0074] In the embodiment of Figures 8a to 8c, the second part 80057 and the threads 8311 are produced by expansion. Alternatively, the second part can be produced by expansion, and the threads can be obtained by rolling using rollers. In this embodiment, the edging is carried out after the formation of the threads. The first part forms the ring 8031.

[0075] In the embodiment of Figures 9a to 9c, the second part 90057 and the threads 9311 are produced by expansion. In this embodiment, the second part 90057 forms the ring 9031.

[0076] The invention is not limited to the embodiments presented and other embodiments will become apparent to those skilled in the art. List of references

[0077] 1: packaging3, 5003, 6003: packaging body31, 5031, 6031, 7031, 8031, 9031: ring311, 5311, 6311, 7311, 8311, 9311: net33, 5033, 6033, 7033; 8033, 9033: opening edge35: metal foil5: twist-off cap51: panel53: skirt531: rolled edge5313: lug7: seal5005, 6005, 7005, 8005, 9005: ferrule50051, 60051, 70051, 80051, 90051: connecting part with the cap50053, 60053, 70053, 80053, 90053: free edge of the connecting part60055, 70055, 80055, 90055: first part60055d, 70055d, 80055d, 90055d: diameter of the first part60057, 70057, 80057, 90057: second part60057d, 70057d, 80057d, 90057d: diameter of the second part70059, 80059, 90059: free edge intended to be edged5007: molding

Claims

Packaging body (3, 5003, 6003) having an end (31, 5031, 6031, 7031, 8031, 9031) forming a ring having an edge (33, 5033, 6033, 7033; 8033, 9033), delimiting an access opening inside the body (3), called the opening edge, the ring (31, 5031, 6031, 7031, 8031, 9031) having threads (311, 5311, 6311, 7311, 8311, 9311) intended to cooperate by screwing with a twist-off cap (5) equipped with a sealing gasket (7), this gasket (7) being intended to cooperate with the opening edge (33, 5033, 6033, 7033; 8033, 9033) of the ring (31, 5031, 6031, 7031, 8031, 9031) for a hermetic closure of the body (3, 5003, 6003) resistant to heat sterilization, characterized in that it is made of metal. Packaging body (3, 5003, 6003) according to the preceding claim, formed of a metal sheet (35) having a thickness of 0.15 to 0.27 mm, preferably 0.17 to 0.25 mm, even more preferably 0.19 to 0.23 mm, and a hardness of TS260 to TH580 in accordance with standard NF EN 10202 of January 2002, preferably less than or equal to TH435, and more preferably TS290 to TH415. Packaging body (3, 5003, 6003) according to any one of the preceding claims, wherein the threads (311, 5311, 6311, 7311, 8311, 9311) are three to eight in number, distributed along the circumference of the ring (31, 5031, 6031, 7031, 8031, 9031). Packaging body (3, 5003, 6003) according to any one of the preceding claims, wherein each thread (311, 5311, 6311, 7311, 8311, 9311) extends over 1 / 8 to 1 / 3 of the circumference of the ring (31, 5031, 6031, 7031, 8031, 9031). Packaging (1) comprising a packaging body (3, 5003, 6003) according to any one of the preceding claims and a twist-off cap (5) designed to cooperate by screwing with the threads (311, 5311, 6311, 7311, 8311, 9311) of the packaging body (3, 5003, 6003), the cap (5) being equipped with a sealing gasket (7) designed to cooperate with the opening edge (33, 5033, 6033, 7033; 8033, 9033) of the ring (31, 5031, 6031, 7031, 8031, 9031) of the body (3, 5003, 6003) for a hermetic closure of the body (3, 5003, 6003) resistant to heat sterilization. Packaging (1) according to the preceding claim, wherein the seal (7) is made of a thermoplastic elastomer material, and is suitable for resisting heat sterilization. Packaging (1) according to claim 5 or 6, wherein the twist-off capsule (5) comprises a panel (51) and a skirt (53) including at its outer end a rolled edge (531) extending radially inwards, the rolled edge (531) including lugs (5313), preferably three to eight lugs (5313) distributed over the circumference of the outer end of the rolled edge (531), and each lug (5313) is intended to cooperate with a thread (311, 5311, 6311, 7311, 8311, 9311) of the packaging body (3, 5003, 6003), by direct contact between the thread (311, 5311, 6311, 7311, 8311, 9311) and the lug (5313). A method for manufacturing a packaging body (5003, 6003) according to any one of claims 1 to 4, comprising the following steps: - during a so-called "rolling" step, a free edge (50053, 60053, 70053, 80053, 90053) of a portion (50051, 60051, 70051, 80051, 90051) of a ferrule (5005, 6005, 7005, 8005, 9005), referred to as the "cap connection portion", is rolled outwards or inwards to form an opening edge (33, 5033, 6033, 7033; 8033, 9033) of the packaging body (3, 5003, 6003),- before or after the rolling stage, we form threads (311, 5311, 6311, 7311, 8311, 9311) on the connecting part (50051, 60051, 70051, 80051, 90051). A manufacturing method according to the preceding claim, wherein first (60055, 70055, 80055, 90055) and second (60057, 70057, 80057, 90057) parts of the ferrule (6005, 7005, 8005, 9005) are formed, having different diameters (60055d, 70055d, 80055d, 90055d, 60057d, 70057d, 80057d, 90057d), the first part (60055, 70055, 80055, 90055) having a diameter (60055d, 70055d, 80055d, 90055d) smaller than that (60057d, 70057d, 80057d, 90057d) of the second part (60057, 70057, 80057, 90057). Manufacturing process according to the preceding claim, in which the first part (60055, 70055) is produced by shrinking the ferrule (6005, 7005). Manufacturing method according to any one of claims 8 to 10, further comprising a step of outwardly edging a free edge (70059) of the ferrule (7005) opposite the free edge (70053) of the ferrule intended to be rolled. Manufacturing method according to claim 9, wherein the second part (80057, 90057) is produced by expansion of the ferrule (8005, 9005). Manufacturing method according to the preceding claim, further comprising a step of edge-banding a free edge (80059, 90059) of the ferrule (8005, 9005) opposite the free edge (80053, 90053) of the ferrule intended to be rolled. Manufacturing process according to claim 12 or 13, wherein the rolling is carried out before the expansion step enabling the production of the second part (80057, 90057). A manufacturing method according to any one of claims 8 to 13, wherein the first (60055, 70055, 80055) or the second part (90057) forms the ring (6031, 7031, 8031, 9031).