MXNL04000077A - Linerless metallic cap closure and method of fabricating the same. - Google Patents

Abstract

A linerless metallic closure includes a metallic closure shell, as for example, the type used for crown caps or roll-on caps. A foamed material layer is applied to an inside surface of the metallic shell such that application of the linerless closure to a container hermetically seals it by a contact between a portion of the material layer on the shell and the container's rim. A method of fabricating linerless closures includes providing a metallic sheet; applying a foaming material layer to one of the surfaces of the metallic sheet, and forming the closure from the metallic sheet. The method also comprises applying and curing a coat of varnish, imprinting the metallic sheet with at least one of a brand name a producer logo, and a promotional message, and curing said ink before said applying the foaming material layer.

Description

TITLE OF THE INVENTION METAL LINE WITHOUT LINE AND METHOD FOR ITS MANUFACTURE BACKGROUND OF THE INVENTION 0 FIELDS OF THE INVENTION The present invention relates to closures or caps that are used in containers designed to retain and store liquids and in general and more specifically to a metal lid without 5 liner.

BACKGROUND Q Bottles of many shapes, sizes and types of materials have been widely used for the content and transportation of different liquids including those for human consumption such as beer, soft drinks, water, juices, prepared beverages and milk, as well as liquids used for other purposes. such as cleaners, materials used in different industrial processes and the like. In many of these uses, a plastic or metal lid is provided for proper sealing of the contents of the bottle to prevent leakage to the outside while contaminating foreign substances from the outside. The covers are usually composed of a metallic or plastic body and an inner liner designed to maintain the pressure and liquid content inside the container. These liners are typically made of one or several layers of the same material or of various materials Q such as cork, rubber, latex, polyvinyl chloride (PVC), and PVC-free compounds arranged between the inner face of the lid and the upper surface of the bottle's peak. The time required and the expensive procedure to apply the liner inside the lid have been significantly reduced by the introduction of linerless plastic lids, but to date, linerless metal lids have not been developed.

Usually, during the process of manufacturing a metal cap, different layers of inks are first deposited on a surface of a metal plate to create logos and promotional messages followed by the application of a transparent protective varnish and a subsequent curing in a continuous oven. The printing can be done on the other side of the metal surface for promotional campaigns and games. The shells of the covers are then produced in a die-cutting process, after which the liners are applied to the interior of the bodies before they can be applied in the closing of the bottles. The application of the liner material is typically expensive and time consuming because they are usually applied separately from the decorating and forming or stamping processes, thus increasing labor costs by reducing production.

There have been some published patents for plastic linerless lids, including for example: (i) US 5,158,195, US 4,925,617, US 4,872,304 US 4,708,255 and US 4,770,309 (all assigned to Tri-Tech International Inc.); (ii) US Patent 3,948,405 (assigned to VCA Corporation); (ii) US Patent 4,741,447 (assigned to American National Can Company). All of these patents use various types of sealing protrusions projecting from the inner surface of the plastic bottle cap. These projections, extend from the top and / or the skirt of the bottle, act as a sealing ring or rings having different designs in sectional cut and are located in different arrangements.

These are some of the reasons why one would prefer a metal lid over one made of plastic. The manufacture of plastic lids usually involves injection molding machinery complicated and expensive, particularly in the case of liner-free plastic lids. There are also special requirements for construction bottlenecks for applications using plastic caps. In addition, due to the manufacturing process of injection molding, plastic caps are very difficult to print with the manufacturer's logos, promotional messages, etc., besides the fact that the printed finish with metal surfaces is much more attractive . Also, consumer preference may require the use of a metal crown cap, particularly when used with traditional drinks and luxury presentations such as, for example, beer.

Although there are metal crown caps of different types, sizes and designs of corrugations; all of them require a liner to function properly. Therefore, there is a need for a metal lid that maintains the functionality supported by the metal covers, such as the ability to print logos and promotional images on them, and at the same time, reduce the procedure to produce and apply the liners that It is expensive and time-consuming, therefore reducing the cost of labor and increasing production.

BRIEF SUMMARY OF THE INVENTION The present invention relates to a metal closure without liner for containers for liquids and the methods for manufacturing them, such as metal closures being able among other things to eliminate the need for additional manufacturing time expense associated with the use of liners. .

A metallic closure according to the function of the invention, comprises a metal shell having an upper part and a circular side skirt, and a layer of foamed material deposited on the inner surface of the upper wall of the shell, in such a way that the application of closure without liner to a container it seals hermetically by the contact between a part of the layer of foamed material in the upper part and with the peak of the container.

A method for manufacturing a metal closure without a liner according to another embodiment of the invention comprises; a metal sheet an upper surface and a lower surface; the application of a layer of foamed material to one of metal sheet surfaces, and the formation of the closure from the metal foil. The method also comprises the application and curing of a varnish coating, the printing of the metallic sheet with at least one brand name, a logo of a producer, and a promotional message, and the curing of said ink before the application. of the foamed material layer. According to yet another embodiment of the invention, a method for manufacturing a metal closure without liner comprises a metal foil, the formation of at least one shell of the closure from the metal foil, said closure shell having an upper part and a wall circular side and the application of a layer of foamed material on the inner surface of the upper part. Furthermore, according to yet another embodiment of the invention, a method for manufacturing a linerless metal closure comprises a cap-type closure shell having an upper part and a circular side wall, and the application of a layer of a foamed material in the inside of the upper part and the circular side. Additionally, according to still another function of the invention, a method for manufacturing a metal closure without a liner comprises a shell having an upper part in a circular side wall, and the application of a layer of foaming material to the internal surface of the upper part. .

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DD3UJOS To facilitate understanding of the present invention, the description of the invention set forth herein will be provided with reference to the specific representations illustrated in the included drawings. The invention will be described and explained with further details by using the accompanying drawings where: FIG 1 shows a side view of a conventional crown cap.

FIG 2 shows a side view of a first embodiment of the present invention, comprising a steel shell having an inner base coating on the inside and a layer of foamed material completely covering the inner surface of the crown; FIG 3 shows a side view of a second embodiment of the present invention, comprising a steel shell having an inner base coating and a foamed material layer partially covering the inner surface of the crown; FIG 4 shows a conventional view of a cap type cap; FIG 5 shows a side view of a third embodiment of the present invention, fulfilling a cap-like cap having an inner base coating and a layer of foamed material completely covering the inner surface of the cap.

FIG 6 shows a side view of a fourth embodiment of the present invention, fulfilling a cap-like cap having an inner base coating and a foamed material layer partially covering the inside of the cap.

DETAILED DESCRIPTION OF THE INVENTION FIG 1 shows a metal crown cap 10 comprising a metallic element 11 having an upper part 12, an inner part 14, and a corrugated skirt 16 with several corrugations therein. Hereinafter the terms "crown cap", "cap" or "closure" are used interchangeably as synonymous terms. Before the labels and / or texts are printed on the lid, a layer of a base material 22 is applied to the inner surface 14 of the metal element 11, at the top where subsequently a liner 24 is also applied. The general process after the printing of the marks or other figures, is to form the shell of the lid in punching presses. Then, the liner is applied regardless of the material that is made inside the shell of the crown. In some cases a curing operation is necessary to obtain the correct adhesion of the liner to the crown shell.

In use, the metal crown cap 10 is placed with its bottom portion 14 on the upper surface of the glass or plastic bottle top (not shown) with the liner 24 held firmly against the beak ring, preventing leakage of the liquid content as well as other gases, including carbon dioxide used for carbonation. The liner 24 is typically made of different materials such as cork, rubber, latex, PVC, and PVC-free compounds. Once the product is required to be consumed, the metal lid 10 is simply opened with an opener. Other crown caps are designed to allow their removal by rotating the crown cap of the bottle.

FIG 2 shows a first presentation of the crown cap without liner 30 of the present invention. Preferably, the metallic material for the lid includes, for example, tin-free steel, tin plated electrolyte, and aluminum; although the manufacturing process is different for aluminum lids. Prior to the stamping of the metal element 11 in the form of a crown cap one or more layers of lithographic inks (not shown) are deposited on the upper surface 12 to differentiate one design from another mainly with the logo of the producer of the beverage, the logo of the brand of the drink, or with promotional messages. To increase production, it is normal to start the manufacturing process with a metal sheet from which many lids are obtained. The application of the layers of inks is typically done through a number of lithographic processes such as bimetallic plates, etc. Once the impressions were applied, they are cured in a continuous furnace at temperatures in a range of about 150 ° C to about 180 ° C, and more preferably in a range between about 160 ° C and about 165 ° C. Stay of the crown caps without liner in the curing oven is varied between 7 minutes and 15 minutes, and more preferably between 8 minutes and 9 minutes. It is also possible to print these labels and logos, or any promotional message on the inner part 14 of the crown cap without liner 30.

It is also possible to apply a transparent protective varnish on the ink impressions of the upper surface to prevent scratching and damage of that surface and also to allow the mobility of the crown on the cheeks of the bottling lines. Some examples of the application of this protective varnish coating include any of the following methods: application by rollers on the flat metal sheet, electro deposit (roll coating), or spray application technology. Once applied, the protective coating can also be cured in a continuous furnace at a temperature range of about 160 to about 210 ° C and more preferably between about 177 and about 183 ° C. The dwell time of the printed metal sheets in the curing oven for curing the protective varnish coating may vary from about 7 to about 15 minutes, and more preferably between about 8 and about 9 minutes. Additionally, depending on the materials used as coatings or as inks on the crown cap without liner 30, Ultra Violet (UV) light can also be used for curing purposes.

Additionally, a protective layer of organosol and / or base material 22 can also be applied to the bottom portion 14 of the crown cap 30. The main purpose of the organosol layer is to facilitate the adhesion of any kind of liners or layers of material that are applied later. Of course it also helps in providing corrosion resistance in steel caps. The base materials also facilitate the adherence to the lid of the materials (mainly inks) that are applied in subsequent steps. The nature of the base materials depends on the material to be adhered; Example: for PVC-based materials, the base materials are of the vinyl type, and for lithographic inks, the base materials can be polyesters, epoxies or alkyd. Once applied the base material 22 can also be cured in a continuous furnace at temperatures in a range of about 160 to about 210 ° C and more preferably between about 197 and about 203 ° C. This curing time can vary from about 7 to about about 15 minutes, and more preferably between about 8 and about 9 minutes.

As shown in FIG 2, once the layer of the base material 22 has been applied, an additional coating of a layer of foamed material 32 is applied prior to the forming operation to ensure that the bottle will be sealed once the crown cap without liner 30 is properly placed there. In another embodiment of the invention, the foamed material 32 can be applied after the formation of the lid. This foamed material film 32 in the lower part 14 of the crown cap without liner 30 assumes the functionality of a liner with respect to the preservation of the content, of the carbonic gas and all the other performances, including as an example the safety test of the seal, removal torque requirements, etc. The foamed material layer 32 will also be able to accommodate imperfections usually encountered during the manufacturing process, including for example imperfections in the sealing surface of the bottle peak and very wide variations in the tolerances of the bottle peak dimensions. In a preferred embodiment of this invention, the layer of foamed material 32 can meet an assembly of relatively thin layers or sublayers.

As will be understood by those with skills in the field, some of the advantages of this invention include for example: (i) the fact that a liner is not required for the dining functionality, (ii) significant savings, including for example : labor, equipment, spare parts, maintenance, energy, and others, as a result of the elimination of the extrusion operation during the manufacturing process; (iii) a wide range of applicability for any bottle, even recycled ones that have wear defects; (iv) a simplified and expeditious manufacturing process; and (v) applicability in a wide range of bottleneck diameters resulting in a very flexible closure for a broad market.

This foamed material 32 is composed of a foamed compound having the ability to foam during curing. The formulation of the foamed composite film 32 can be based on the mixture of vinyl resins with some additives and foaming agents. The foamed material 32 can be made as a combination of three different types of materials, including a resin, a plasticizer and a foaming agent. The temperature range for the curing process of the foamed material 32 is from about 180 to about 220 ° C, and preferably from about 192 to about 198 ° C. The curing time for the foamed material layer 32 varies between about 1.5 and about 5 minutes, and preferably from about 2 to about 2.5 minutes. Additionally, the thickness of the foamed material film 32 ranges from 0.25 m (0.010 inches) to approximately 0.50 mm (0.020 inches). The preferred thickness of the foamed material film is about 38 mm (0.015 inches).

An example of the resin to be used in the mixture of the foamed material of the present invention is polyvinyl chloride (PVC) in concentration ranges from about 40 to about 50% by weight, more preferably about 45%. A preferred method for the application of the foamed material mixture is through the use of rollers commonly used in the lithographic industry. Some examples of plasticizers are di-octylnalate (DOP) and di-isodecyl phthalate (DIP), both having concentrations ranging from 50 to 55% by weight, preferably 52.5%. Mixtures of these plasticizers at similar concentration levels are also possible. The DOP plasticizer has the following chemical formula: Additionally some examples of foaming agents used in the manufacture of foamed material layer 32 may be azodicarbonamide (ADC), modified azodicarbonamide (MADC), di-nitrosopentamethylenetetramine (DNPT), hydrazide bensulfonyl (BSH), 4,4-oxibisbenzen sulfonyl hydrazide ( OBSH), toluensulfonyl semicarbazide (TSSC), 5-penyltrazole, hydrazide derivative, and sodium bicarbonate (SBC). Preferred concentrations of the foaming agents used in the manufacture of foamed material layers 32 range from about 1 to 5% by weight, and preferably about 2.5%. Additionally, the preferred foaming agent is sodium bicarbonate or SBC. Finally, the reaction of the compound during foaming while the crown cap 30 being cured can be represented by the following chemical reaction: 2NaHC03 + 20¾ COOH 2C6H5COONa + H20 + 2C02 There are at least two alternatives for applying the material to form the layer of foamed material 32 in the crown cap without liner 30. In the first method, the material is first applied to the metal sheet before that the metal crown caps are punched out of the sheet. A crown cap without liner 30 made using this method is shown in FIG 2 after the metal sheet is punched out to form the crown cap. As shown, the layer of foamed material 32 is formed on the entire surface of the part. inner 14 of the crown cap without liner 30, including the corrugated skirt 16 as well as the corrugations of the skirt 18. This first method is attractive because it eliminates at least the need to separate the work station for the application of the foamed material layer 32 , in this way capital cost is reduced and production is increased.

The application of the foamed material layer 32 can also be carried out after the die-cutting of the crown caps. FIG 3 shows another representation of a crown cap without liner 30 having the foamed material 32 applied after the formation of the crown cap. In this case, the amount of foamed material used is reduced because the skirt 16 and the corrugations therein are not covered. However, sufficient coverage of the inner portion of the portion 14 must be achieved to ensure that the crown cap without liner 30 can achieve its sealing function.

The present invention is also applicable to cap-type caps. FIG 4 shows a side view of a bushing cap 40, comprising a metal element 41 having an upper part 12, and a lower part 14, and threads of the lid 42 downwards. Similar to FIG 1, a cap-type cap may have a layer of a base material 22 applied by the inner surface 14 of the meta element 41 in the upper part of which a subsequent liner 24 is also applied. FIG 5 shows a third representation of the invention related to a cap-like cap without liner 50. The preferred material for these cap-type caps is aluminum. As shown, like the application of films in FIG 2, a clear varnish coating (not shown) and a base material film 22 is applied to the bottom portion 14 of the cap without bushing liner 50. Additionally , a layer of foamed material 32, it is applied to the entire entire surface of the bottom part 14 of the lid without liner type 50. The same materials for the different films, compositions, temperature ranges and curing times stated for the crown cap without liner 30 are applicable to the lid without bushing type liner 50. As with the representation of FIG. 3, as shown in FIG. 6, it is also possible to apply the foam material compound 32 only to a fraction of the inner surface 14 of the bushing cap without liner 50 The method for manufacturing lids or closures without liner is also within the scope of this invention. In this matter, the details presented above in conjunction with the apparatus, including materials, compositions, manufacturing conditions, etc. They are also applicable to the producer's method and will not be repeated. Initially, metal sheets, preferably tin-free steel or electrolytic tinplate, are applied with at least one coating of varnish and properly cured. A protective layer of organosol is then applied to facilitate the movement of the lids through the manufacturing process. Once the organosol and varnish have been applied and cured, lithographic inks are applied over the varnish and cured. After all, a layer of foamed material is applied on the inside of the metal plate.

Once the application of the foamed material has been completed, the metal sheets are then die cut to form the shells of the closure to produce the crown caps without liner. It is also possible first to form the shells of the metal sheets before the application of the foamed material. In this case, there will be significant savings in the foamed material because it would be applied only on the inner surface at the top of the shell and not on the entire interior surface including the area of the corrugations. Cap liner without liner made preferably of aluminum can be manufactured according to the presentation of the present invention. In this case, the cap-type aluminum cap is first formed using known processes and then the foamed material is applied to either the entire inner surface or a fraction thereof.

Although the typical representations and details have been explained above with the intention of illustrating several of the best modes of the present invention as applied to crown lids without liner or cap type lids and the like, it is understood that some changes or variations in the methods, equipment , and systems set forth herein may be implemented with the scope of this invention. The scope of the invention is appropriately determined by the claims that follow below.

Claims (30)

1 - . 1 - A metal closure without liner for a container having an opening with a peak, said closure without liner comprising: a shell of the metal closure having an upper part and a circular side surface; and a layer of foamed material placed on the inner surface of said upper part in such a way that the application of said closure to said container hermetically seals said container by the contact between said part of said layer of foamed material in said circular part and said peak .

2. - The metal closure without liner of claim 1, wherein said layer of foamed material is deposited on the inner surface of said upper part, and an inner surface of said side wall.

3. - The metal closure without liner of claim 1, wherein the body of said metal closure can be made of steel and aluminum.

4. - The metal closure without liner of claim 1, wherein the body of said metal closure can be a crown cap and a cap type cap.

5. - The metal closure without liner of claim 1, wherein the body of said metal closure further comprises at least one coating of varnish.

6 -. 6 - The metal closure without liner of claim 1, wherein the composition of said layer of foamed material comprises a vinyl resin, a plasticizer and a foaming agent.

7. - The metal closure of claim 1, wherein the thickness of said foamed material layer is between about 0.010 and about 0.020 inches.

8. - The metal closure of claim 7, wherein the thickness of said layer of foamed material is about 0.015 inches.

9. - The metal closure of claim 6, wherein said vinyl resin is polyvinyl chloride having a concentration in said composition of about 40 to about 50% by weight.

10. - The metal closure of claim 9, wherein said concentration is about 45% by weight.

11. - The metal closure of claim 6, wherein said plasticizer is at least one of di-octyl phthalate (DOP) and di-isodecyl phthalate (DIP) having a concentration in said composition ranging from about 50 to about 55% by weight.

12. - The metal closure without liner of claim 11, wherein said concentration is about 52.5% by weight.

13 -. 13 - The metal closure without liner of claim 11, wherein said plasticizer (DOP) has the following formula:

14. - The metal closure of claim 6, wherein the foaming agent is at least one of azodicarbonamide (ADC), a modified azodicarbonamide (MADC), dinitrosopentametüentetraniina (DNPT), benzensulfonyl hydrazide BSH), 4,4 oxisbenzen sulfonyl hidaracide (OBSH), toluensulfonyl semicarbazide (TSSC), 5-phenyltrazole, a derivative of hydrazide, and sodium bicarbonate (SBC). 15. - The linerless metal closure of claim 14, wherein the concentration of said foaming agent in said composition ranges from about 1 to about 5% by weight. 16. - The metal closure without liner of claim 15, wherein the concentration of said composition is about 2.5% by weight. 17. - A method of manufacturing the metal closure without a liner, comprising a metal sheet having an upper surface and a lower surface; the application of a layer of foamed material to one of its surfaces; and forming said closure from said metal foil. 18. - The method of claim 17, further comprising applying a varnish coating to said metal sheet and curing said coating duration prior to the application of said foamed material layer. 19. - The method of claim 18, further complying with the transfer of an ink to said metal sheet, to print there at least one logo of a brand, a logo of a manufacturer or a promotional message, and the curing of said ink before the application of said layer of foamed material. 20. - The method of claim 19, wherein said foamed material layer foams during the curing of said layer of foamed material. 21. - The method of claim 17, wherein said layer of foamed material comprises a combination of vinyl resin, a plasticizer, and a foaming agent. 22. - The method of claim 21, further comprising curing said foamed material layer in an environment having a temperature ranging from about 180 to about 220 ° C. 23. - The method of claim 22, wherein said temperature ranges from about 192 to about 198 ° C. 24. - The method of claim 22, wherein the curing time of said layer of foamed material in said environment varies from about 1.5 to about 5 minutes. 25. - The method of claim 24, wherein said curing time ranges from about 2 to about 2.5 minutes. 26. - The method of claim 17, wherein the thickness of said foamed material layer is between about 0.010 and about 0.020 inches. 27. - The method of claim 26, wherein said thickness is about 0.015 inches. 28. - A method of manufacturing the metal closure without liner, fulfilling: a metal sheet; the formation of at least one body of the closure from said metal sheet, said closure having an upper part and a side wall; and the application of a layer of foamed material applied to the inner surface of said upper part. 29. - A method of manufacturing the metal closure without liner, comprising: a body of the cap type closure having an upper part and a circular side wall; and the application of a layer of foamed material on the inner surface of said upper part. 30. - The method of claim 29, wherein said application further comprises the application of layers of foamed material on the inner surface of said side wall.