INTEGRALLY MOULDED PLASTIC PLUG RING CAP

Abstract

A screw cap produced by a bi-injection moulding process is disclosed herein in which discrete thermoplastics are moulded sequentially for resulting correspondingly into a soft inner lip and outer hard shell for sealing containers or conduits having an externally threaded neck, said containers or conduits being directed at holding or conveying chemical, food, and pharmaceutical preparations.

Claims

1) A cap for sealing a container having an externally threaded neck thereon, comprising a) An outer shell of formable material moulded to assume a cylindrical geometry, said outer shell being composed of a flat circular top having a circumferentially-continuous, internally-threaded side wall descending at a right angle from said flat circular top to end in an open mouth to be received on the externally threaded neck of the container for sealing the same; b) An inner plug ring of a formable material moulded to assume an annular geometry and arranged to descend concentrically from underbelly of the flat circular top of the outer shell to an extent sufficient to allow force-fitting onto the externally threaded neck of the container when the cap is screwed home thereon; and c) A tamper-evident means continuous with mouth of the outer shell, said ring being composed of two initially joined, but separable members of which one member is attached at open end of the outer shell and the other member fixedly embraces the externally threaded neck of the container Characterized in that i) The formable material of the inner plug ring is selected to be one having less rigidity than that of the outer shell to allow a tight fit and therein accommodating any undulations on lip of the externally threaded neck; ii) The formable material of the inner plug ring is selected to be one having high chemical resistivity to allow inert behavior upon contact with contents of the container; and iii) The outer shell and inner sealing plug ring are integrally moulded together, thereby allowing a leak-proof seal when the cap is received onto the container.

2) The cap for sealing a container having an externally threaded neck thereon as claimed in claim 1, wherein the container is an article for storing or conveying fluids, said article being chosen among a bottle, vial, tube, jerry-can, conduit, tube or equivalent.

3) The cap for sealing a container having an externally threaded neck thereon as claimed in claims 1 and 2, wherein the cap is a screw-type cap allowing a screw-type fit when received rotatably on the threaded neck of the container.

4) The cap for sealing a container having an externally threaded neck thereon as claimed in claim 1, further including an aperture passing through the flat circular top of the outer shell for receiving a vent plug.

5) The cap for sealing a container having an externally threaded neck thereon as claimed in claim 4, wherein the vent plug is a plastic plug with a membrane inside that allows gases, but not liquids, to selectively pass through therein allowing breathability to contents of the container when sealed using the cap.

6) The cap for sealing a container having an externally threaded neck thereon as claimed in claims 1 and 3, wherein threading on the inner wall of the outer shell and neck of the container have a complementary pitch to thereby allow the cap to assume a sealed, leak-proof fit when received rotatably on the threaded neck of the container.

7) The cap for sealing a container having an externally threaded neck thereon as claimed in claim 1, wherein the tamper-evident means are selected among a perforated-type and racket type tamper-evidence rings.

8) The cap for sealing a container having an externally threaded neck thereon as claimed in claim 1, wherein the formable material of the outer shell is selected among the group of thermoplastics including polyethylene, High-density polyethylene, and polypropylene.

9) The cap for sealing a container having an externally threaded neck thereon as claimed in claims 1 and 8, wherein the formable material of the inner plug ring is selected among flexible sealing materials, a compounded polypropylene thermoplastic in particular, which are compatible with the formable material of the outer shell for adhesion there-with while undergoing injection moulding.

10) A method for production of the cap recited at claim 1, comprising a) Moulding of formable material at an increased temperature to obtain an outer shell of cylindrical geometry, said outer shell being composed of a flat circular top having a circumferentially-continuous, internally-threaded side wall descending at a right angle from said flat circular top to end in an open mouth to be received on the externally threaded neck of the container for sealing the same; and b) Maintaining the outer shell obtained at step a) at high temperature while moulding of an inner plug ring in form of a skirt integral to the outer shell by injecting the sealing area of the outer shell under high temperature and pressure conditions with a formable material less rigid than that of the outer shell, therein causing the outer shell and inner plug ring to fuse into a unibody construct.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0031] The present invention is explained herein under with reference to the following drawings, in which:

[0032] FIG. 1 illustrates a prior art plastic cap with wad inserted in it, and the bottle to which it is coupled having an induction seal.

[0033] FIG. 2 illustrates a prior art inner plug made of plastic and the container to which it is received.

[0034] FIG. 3 (a) and (b) illustrate a schematic cross-sectional view and bottom side perspective view respectively of the CRTESS cap made according to the disclosures hereof.

[0035] FIG. 4 (a) and (b) are schematic illustrations of the CRTESS cap in use in conjunction with a jerry-can and bottle respectively, particularly identifying therein the tamper-evident ring provided according to the disclosures hereof.

[0036] FIG. 5 (a) to (d) are top view, isometric view, side view, front view, and bottom views respectively of the CRTESS cap made according to the disclosures hereof.

[0037] FIG. 6 is a schematic cross-sectional view of the functional seal achieved by the CRTESS cap according to the disclosures hereof.

[0038] FIG. 7 (a) to (c) are side view, top view, and isometric view of one embodiment hereof, being the 61 mm CRTESS CAP with provision in cap for vent plug.

[0039] FIG. 8 (a) to (c) are side view, top view, and isometric view of another embodiment hereof, being the CRTESS CAP with racket type tamper-evidence.

[0040] FIG. 9 (a) to (c) are side view, top view, and isometric view of another embodiment hereof, being the CRTESS CAP with sealing layer around annular space of the cap.

[0041] The above drawings are illustrative of particular examples of the present invention but are not intended to limit the scope thereof. The drawings are not to scale (unless so stated) and are intended for use solely in conjunction with their explanations in the following detailed description.

[0042] In above drawings, wherever possible, the following same references and symbols have been used throughout to refer to the same or similar parts [0043] (01)CRTESS cap [0044] (02)Outer shell [0045] (03)Inner plug ring [0046] (04)Lip of bottle (05) [0047] (05)Bottle [0048] (06)Knurling [0049] (07)Thread on neck (08) [0050] (08)Externally threaded neck of bottle (05) [0051] (09)Tamper-evident ring [0052] (10)Vent plug

[0053] Though numbering has been introduced to demarcate reference to specific components in relation to such references being made in different sections of this specification, all components are not shown or numbered in each drawing to avoid obscuring the invention proposed.

SUMMARY OF THE INVENTION

[0054] In a preferred embodiment disclosed hereof, there is provided an inventive integrally moulded plastic plug ring cap for sealing a container having an externally threaded neck thereon. Also disclosed is a method for forming said cap. The present inventor proposes to address at least majority of the shortcomings of state-of-art by advantageous implementation of a bi-injection moulding process wherein discrete thermoplastics are moulded sequentially for resulting correspondingly into a soft inner lip. Outer hard cap/shell is optionally provisioned with external knurling for better grip and to be compatible with automatic capping machines. Usage of the closure proposed herein is of screw fit type for quick disconnect coupling with the container/conduit at which said closure is intended to be received. Process involved does away with more complex, costly, and time-consuming induction sealing practiced traditionally. Resulting article is a integrally moulded plastic plug ring cap capable of providing a guaranteed, reversible hermetic seal when received at the mouth of means for holding or conveying chemical, food, and pharmaceutical preparations.

[0055] Attention of the reader is now requested to the detailed description to follow which narrates a preferred embodiment of the present invention and such other ways in which principles of the invention may be employed without parting from the essence of the invention claimed herein.

DETAILED DESCRIPTION

[0056] Principally, general purpose of the present invention is to assess disabilities and shortcomings inherent to known systems comprising state of the art and develop new systems incorporating all available advantages of known art and none of its disadvantages.

[0057] Before undertaking the detailed description of the invention below, it may be advantageous to set forth definitions of certain words or phrases used throughout this patent document: the terms include and comprise, as well as derivatives thereof, mean inclusion without limitation; the term or is inclusive, meaning and/or; the phrases associated with and associated therewith, as well as derivatives thereof, may mean to include, be included within, interconnect, with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term CRTESS cap shall mean Chemical-Resistant Tamper-Evident Self-Sealing cap which is the integrally moulded plastic plug ring cap proposed in the present invention; PET shall mean Poly-Ethylene Terephthalate; HDPE shall mean High-density polyethylene; PP shall mean polypropylene; PE shall mean polyethylene; means for holding or conveying chemical, food, and pharmaceutical preparations shall refer any one among a bottle, vial, tube, jerry-can, conduit, tube or equivalent which additionally are intended to be synonymous in this paper without affecting essence of the invention.

[0058] The present invention primarily focuses on avoiding, or at least minimizing the issues recited in the background section of this paper. Accordingly, the disclosures herein are directed towards the inventive construction, methods of preparation and use of a leak-proof closure, being the CRTESS cap, having an infallible but quick disconnect coupling when removably received in conjunction with means for holding chemical, food, or pharmaceutical preparations, particularly a container having an externally threaded neck such as one among a bottle, vial, tube or equivalent. Further embodiments of the present invention are directed to a corollary aspect, being a leak-proof closure, being a cap, having an infallible but quick disconnect coupling when removably received in conjunction with means for dispensing, such as a valve, tube or equivalent.

[0059] According to a first aspect of the present invention as depicted in the accompanying FIGS. 3(a) and 3(b), construction of the CRTESS cap (01) includes a plastic outer shell (02) of cylindrical geometry that provides strength and rigidity, and a chemically resistant inner plug ring (03) that provides leak-proof character to the CRTESS cap (01). The outer shell (02) is composed of a flat circular top having a circumferentially-continuous, internally-threaded side wall descending at a right angle from said flat circular top to end in an open mouth to be received on the externally threaded neck of the container for sealing the same.

[0060] According to one aspect of the present invention, inner sealing layer, that is the inner plug ring (03) is of chemically resistant soft material (flexible sealing material which is moldable and compatible with PE materials for adhesion while injection moulding) which helps in effective sealing against lip (04) of mouth of the bottle (05) at which said CRTESS cap (01) is to be received. In a related aspect, the inner plug ring (03) is moulded to assume an annular geometry and arranged to descend concentrically from underbelly of the flat circular top of the outer shell to an extent (height, thickness, conicity, etc) sufficient to allow force-fitting onto the externally threaded neck of the container when the cap is screwed home thereon.

[0061] According to another related aspect of the present invention, the soft material of the inner plug ring (03) ensures that undulations/unevenness in surface of the bottle lip (04) to be accommodated while providing a secure seal. This in turn, ensures that passage of air, heat, and/or materials in-between the CRTESS cap (01) and the bottle (05) at which it is received is nil, or at least limited to insignificant levels. Therefore, the CRTESS cap (01) has infallible leak-proof character when removably received in conjunction with means for holding chemical, food, or pharmaceutical preparations.

[0062] According to another related aspect of the present invention, tamper-evident means continuous with mouth of the outer shell (02) are included for positive indication of tampering readily discernable to eyes of the user. Said tamper-evident means being composed of two initially joined, but separable members, such as a perforated tear-type or ratchet-type ring, of which one member is attached at open end of the outer shell (02) and the other member fixedly embraces the externally threaded neck (08) of the container

[0063] According to another aspect of the present invention explained with combined reference to the accompanying FIG. 3(a), FIG. 3(b) and FIG. 4, the CRTESS cap (01) optionally is made to have knurling (06) on its external surface for aesthetics as well as for the CRTESS cap (01) to be used in conjunction with an automatic capping machine. Internal surface of the outer shell (02) has a thread for screw fit onto matching thread (07) on neck (08) of the bottle (05). Mouth of bottle (05) sits in the annular area made in the CRTESS cap (01) by the inner plug ring (03).

[0064] According to another aspect of the present invention explained with reference to the accompanying FIG. 4, the CRTESS cap (01) further includes a tamper-evident ring (09) that sits around neck (06) of the bottle (07). The tamper-evident ring (09) is designed to be broken off and remains on the bottle (05) when the CRTESS cap (01) is removed from the bottle (05) for the first time, thereby giving an immediate positive indication of tampering readily discernable to eyes of the user. For such effect, it is critical that diameter and profile of the locking ring (10) that sits around neck (08) of the bottle (05) has to be maintained within tolerance.

[0065] According to a second aspect of the present invention it would be necessary to consider the process for preparing the CRTESS cap (01) subject hereof. In a preferred arrangement, the CRTESS cap (01) is prepared via a bi-injection moulding process wherein the inner plug ring (03) is molded first, and followed by molding of the outer shell (02). This ensures that the resulting product, that is the CRTESS cap (01), has a one piece construction being achieved via a simplistic process and thereby does away with multiplicity of operations and child components otherwise involved in manufacturing prior art closures of equivalent function.

[0066] It shall be appreciated from the preceding paragraph, that induction sealing is entirely avoided in the process for preparing the CRTESS cap (01) proposed herein. Also, no separate PE layer or rubber gasket or a form layer is needed to ensure leak-proof character. In fact, sealing is totally provided by the integral sealing layered construction recited hereabove. Therefore, manual labour involved, electricity, shop-floor space, and time involved in said induction sealing step is entirely avoided.

[0067] Implementation of the present invention is intended to encompass various embodiments, among which a few are explained below with reference to certain examples that illustrate generically the manner in which principles of the present invention may be employed.

EXAMPLE 1: PROTOCOL FOR PRODUCTION OF THE CRTESS CAP

[0068] As mentioned in the foregoing disclosures, the CRTESS cap (01) proposed herein is prepared via a bi-injection moulding process wherein the inner plug ring (03) is molded first, and followed by molding of the outer shell (02).

[0069] According to one feature of the present invention evident from Example 1 above, the inner plug ring (03) is fused with the outer cap (02) during the molding process itself, hence the resulting CRTESS cap (01) has a single component/unibody construction. Hence no problems are experienced as otherwise such as wads jumping out of the caps or being displaced out of position observed in prior art solutions. FIG. 5 (a) to (d) are top view, isometric view, side view, front view, and bottom views respectively of the final product, that is the CRTESS cap (01) made according to the disclosures hereof.

[0070] In a preferred embodiment, a plastic HPDE cap is maintained during moulding at an increased temperature and sealing area is injected under high temperature and pressure conditions with a chemically-resistant material to form the inner plug ring. Formable material of the inner plug ring is selected to be one having less rigidity than that of the outer shell. High temperatures cause the sealing area to fuse into a single component. The sealing portion is moulded to form a skirt, therein forming the walls and horizontal area beneath the cap. This imparts a very distinct advantage to the cap by providing a very good sealing around the mouth of the bottle as depicted in the accompanying FIG. 6. Consequently, the sealing portion engages with the bottle neck and provides 100% leak-proof character every time the cap is closed.

EXAMPLE 2: TESTING OF THE CRTESS CAP

[0071] a) Drop test: The CRTESS cap made using the protocol of Example 1 was received via screw fit at mouth of a liquid filled bottle. Said bottle with CRTESS cap was dropped from various heights. Here, it was observed that the bottle with CRTESS cap neither ruptures nor leakage was observed from the bottle. This concludes that the CRTESS cap successfully cleared the standard drop test applicable for articles of its nature. [0072] b) Leakage test: The CRTESS cap made using the protocol of Example 1 was received via screw fit at mouth of a liquid filled bottle. Said bottle with CRTESS cap was subjected to an air pressure of 20 kPa for 5 min. Here, it was observed that the bottle with CRTESS cap neither ruptures nor leakage was observed from the bottle or said cap. This concludes that the CRTESS cap successfully cleared the standard leakage test applicable for articles of its nature. [0073] c) Hydraulic test: The CRTESS cap made using the protocol of Example 1 was received via screw fit at mouth of a liquid filled bottle. Said bottle was subjected for a period of 30 minutes to a hydraulic gauge pressure of 100 kPa. Here, it was observed that the bottle with CRTESS cap neither ruptures nor leakage was observed from the bottle or said cap. This concludes that the CRTESS cap successfully cleared the standard hydraulic test applicable for articles of its nature. [0074] d) Stacking test: The CRTESS cap made using the protocol of Example 1 was received via screw fit at mouth of a liquid filled bottle. A superimposed weight was placed on top of a plywood sheet placed on the top of said bottle for a period of 24 hours. The weight was equivalent to stack height of 3.0 m. Here, it was observed that the bottle with CRTESS cap neither ruptures nor leakage was observed from the bottle or said cap. This concludes that the CRTESS cap successfully cleared the standard stacking test applicable for articles of its nature.

EXAMPLE 3: ALTERNATIVE VARIANTS OF THE CRTESS CAP

[0075] The CRTESS cap proposed herein may be produced in alternative versions depending on the specific use-case and application intended. The following versions are few non-limiting examples in this line-a) [0076] a) CRTESS Cap with a vent plug insertion option and self-sealing: As seen in the accompanying FIG. 7 (a) to (c), provision is made in the CRTESS cap itself to insert a vent plug (011). The vent plugs are third party sourced components comprising a plastic plug with a membrane inside. The membrane doesn't allow liquid to pass only air to pass. Hence any pressure difference which occurs inside the container is solved by the vent plug. In this variant of the CRTESS cap, the inventor named herein has made a provision such that the vent plug can be directly inserted into the CRTESS cap (this is unconventional as usually such vent plugs are inserted into the inner plug or comes as a part of the sealing wad) [0077] b) CRTESS Cap with complete top seal sealing and racket type tamper-evidence ring: As seen in the accompanying FIG. 8 (a) to (c), this variant is identified in including a racket type tamper-evidence ring in conjunction with the CRTESS cap. Top of the CRTESS cap is also provided with sealing layer. [0078] c) CRTESS Cap where sealing is at only the annular region of the cap: As seen in the accompanying FIG. 9 (a) to (c), this variant is identified in including the sealing layer around the annular space of the CRTESS Cap. Here, the sealing layer doesn't cover the entire top area of the CRTESS Cap but it is injected in the middle area to thereby the material to flow to the annular plug ring area. Sealing is thus provided at the annular region area.

[0079] The CRTESS cap proposed herein can be used on a large scale across all bottles with 46 mm and 61 mm neck diameters. However nothing said in this paper shall prohibit scaling up or down, or assuming an alternative profile of the cap, for suiting different neck sizes and profiles of any of presently available or future means holding or conveying any among holding chemical, food, or pharmaceutical preparations.

[0080] As may be appreciated from the foregoing disclosures, the present invention encompasses the production and use of able caps, covers or seals for protecting means for holding or dispensing chemical, food, and pharmaceutical preparations. As such, the present invention is identified in having the following salient features [0081] 1) CRTESS cap is a truly single component solution [0082] 2) Inner plug ring of the CRTESS cap chemically resistant and thus can be safely used in association with means holding or conveying any among holding chemical, food, or pharmaceutical preparations. [0083] 3) CRTESS cap can be used just like any other cap by the user [0084] 4) CRTESS cap can be screwed on using a capping machine [0085] 5) CRTESS cap can be screwed on and off any number of times, thereby allowing repeated usability and recyclability [0086] 6) Process of induction sealing and its associated vices are done away completely in production of the CRTESS cap [0087] 7) Need of separate wads is omitted as induction sealing operation is avoided [0088] 8) Due to bi-injection moulding process, the outer cap and inner plug ring can be provided in different colors, thereby affording greater choice for aesthetics besides being an anti-counterfeiting measure or to validate the authenticity of any product sold in the market (color of inner plug ring is only known to the bonafide manufacturer, and can be varied from batch to batch. Any discrepancy therefore will automatically count as a counterfeit article). [0089] 9) Presence of tamper-evident ring allows positive indication of tampering readily discernable to eyes of the user. [0090] 10) Production protocol is not easily replicable, therefore preventing spurious distributors and manufacturers from introducing duplicates of the the CRTESS cap, thereby increasing assurance of genuineness in minds of users.

[0091] As will be realized further, the present invention is capable of various other embodiments and that its several components and related details are capable of various alterations, all without departing from the basic concept of the present invention. Accordingly, the foregoing description will be regarded as illustrative in nature and not as restrictive in any form whatsoever. Modifications and variations of the system and apparatus described herein will be obvious to those skilled in the art. Such modifications and variations are intended to come within ambit of the present invention, which is limited only by the appended claims.

[0092] It shall be generally noted that at least a major portion of the foregoing disclosures of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in files or records of the receiving Patent Office(s), but otherwise reserves all copyright rights whatsoever.