WO1999046176A1

WO1999046176A1 - Plastic closure liners and closures containing liners

Info

Publication number: WO1999046176A1
Application number: PCT/US1999/005018
Authority: WO
Inventors: Michael L. Price; Rocco D. Walker
Original assignee: Zapata Innovative Closures, Inc.
Priority date: 1998-03-10
Filing date: 1999-03-08
Publication date: 1999-09-16
Also published as: AU2900199A

Abstract

A floating or movable liner (14) for a closure (20) comprising a compressible plastic which includes an upper member (52), such as a disk, and a depending member (56) with a pre-configured profile, preferably an annular bead, at the periphery thereof. The liner is insertable into and moves or floats within the upper portion of the closure. The disk and bead are adapted to provide a pre-configured, thickened portion (54) at and adjacent the periphery of the liner to provide sealing even when the top of the closure flexes upwardly or downwardly.

Description

TITLE OF THE INVENTION

PLASTIC CLOSURE LINERS AND CLOSURES CONTAINING LINERS

FIELD OF THE INVENTION The present invention relates to movable or floating plastic liners for closures. The present invention also relates to closures, such as caps, incorporating the liners of the invention, which are especially useful for maintaining the pressure in containers for gaseous containing products, such as carbonated beverages and beer.

BACKGROUND OF THE INVENTION The function of plastic liners is to provide an adequate seal against leakage from or into the contents of containers. A cap, typically, has a lid and a depending annular skirt, and a liner for the cap, typically, is made of a relatively soft plastic material which is positioned within the upper portion of the cap. In use, the liner provides the seal between the cap and the container, such as a bottle, upon closure of the cap on the container. Liners either can be fixed or floating. Fixed liners are adhered or fixed to the closures which contain them. Different types of liner profiles also are available, e.g., liners for caps from Tapon Corona Iberica, S.A. Whatever the profile, the liners generally are made from soft plastic materials which tend to "flow" into the imperfections in the sealing surfaces of bottles. Should a glass or plastic bottle have a nick in the sealing area which would cause the bottle to leak, the liner normally will flow into this imperfection and provide a seal. With a fixed liner, however, something must give when a consumer tries to open the bottle. Usually, the liner will tear, which requires an extra force to open the bottle. Also, the tear in the liner can adversely affect its sealing properties and can introduce torn away liner material into the container product. Floating or movable liners are not fixed to the cap and generally can move within the upper portion of the cap. With such liners, relative movement is possible, thereby reducing the effort to remove the cap in opening the bottle and reducing the possibility of deleterious tearing of the liners. Commonly, however, the available moving or floating liners do not provide the required sealing. See, for example, the liner of United States Patent No. 3,917,100 which discloses a floating liner in the form of a disk having a uniform thickness and configuration. It has been found that this type of a floating liner may not provide an adequate seal, particularly for carbonated beverages or beer.

Moreover, whether or not a fixed or floating liner is used, it is common to require the caps to be specially configured internally in an effort to provide the desired sealing. Such caps can be more costly than conventional caps and they may be more difficult to make. See, for example, United States Patent Nos. 4,462,502 and 4,658,976, which include special annular internal abutments where the lid and skirt intersect. These configured abutments are provided to engage and deform the liners in an effort to provide sealing as the cap closes the container. SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a new and unique plastic liner which can move or float within the closure, which provides an effective positive seal for a variety of products, including carbonated beverages and beer, which _s not subject to tearing upon the opening of the container, and which does not need a specifically configured closure or cap. In a preferred embodiment, the liner of the present invention comprises a compressible plastic and includes an upper member, such as a disk, and a depending member having a configured profile at the periphery thereof, and preferably an annular peripheral bead. The breadth or diameter of the movable or floating plastic liner is greater than the breadth or diameter of the rim of the container and the liner provides a pre-configured periphery of increased thickness for sealing engagement with and about the container rim. In practice, the plastic liner of the present invention is inserted into and moves or floats within the upper portion of the cap. When ready for use, the cap is closed upon the container or bottle, whereupon the cap and the rim of the container engage the thicker annular periphery of the plastic liner and compress it on and about the rim. In doing so. the peripheral portion of the liner is deformed to provide both a positive and effective seal against leakage from or into the contents of the container.

In the present invention, the pre-configured thickened peripheral portion of the plastic liner provides a relatively soft plastic material which can be compressed to provide the forces needed for effective sealing. At the same time, the described pre-configured thickened depending member can be moved downwardly into sealing engagement about the outer portion of the rim to insure the sealing properties of the seal. In one embodiment, the depending member is an annular bead, wherein the bead is curvilinear and can have a solid generally semi-circular cross-section with an inner concave or radiused segment, intersecting with the underside of the liner's upper member or disk. In use, the depending peripheral bead about the periphery of the liner can engage the corner and outer portions of the container rim when the liner is ironed or pressed over the container rim by the engagement between the cap and the container. In each embodiment, the plastic liner of the present invention provides the desired seal under different sealing conditions generally encountered by liners.

In addition, the plastic liners of the present invention can maintain their sealing properties and provide extra cushioning for impact resistance, e.g., if the container or bottle is dropped from the supermarket shelf and the closure flexes. The positioning and configuration of the thickened peripheral portion also help with sealing of the liner systems of the present invention throughout closure doming and stacking, i.e., when the too of the closure is flexed up or down. For example, the compressed seal area of the plastic liners can move along and extend outwardly about the top of the rim and engage the contracted cap skirt, whereupon the depending pre-configured profiles, e.g., the bead, can move into sealirg engagement with the outer portions of the rim.

BRIEF DESCRIPTION OF THE DRAWINGS The following is a detailed description together with the accompanying drawings of illustrative embodiments of the invention. It is to be understood that the invention is capable of modification and variation apparent to those skilled in the art and within the spirit and scope of the invention.

Figure 1 is an exploded view of a cap, a bottle and a preferred embodiment of the plastic liner of the present invention.

Figure 2 is a cross-sectional view, showing a partially assembled of the cap, plastic liner and container of Figure 1 , wherein the cap, container and liner are in partial engagement.

Figure 3 is a cross-sectional view of the assembled cap, plastic liner and container of Figure 1 , wherein there is full engagement between the cap and the container, and wherein the plastic liner has been compressed and deformed to provide the desired sealing.

Figures 4-10 are cross-sectional views of other embodiments of the plastic liners of the present invention.

PREFERRED EMBODIMENTS OF THE INVENTION Referring now to the drawings and particularly to Figure 1, there is shown an exploded view of a closure 10, a container 12 and a preferred embodiment of the plastic liner 14 of the present invention.

The illustrated closure 10 is a cap 18 having a lid 20 a depending annular skirt 22 with internal engaging means, such as helical threads 24, external gripping serrations 25 and a lower tamper evident band 26.

Above the threads 24 is an annular inner generally planar wall 28 which has a breadth or diameter that is greater than the inner breadth or diameter defined by the threads 24. This described space or chamber 32 above the threads 26 houses the plastic liner 14 and within which the liner 14 moves or floats. As illustrated, the cap 18 is of a conventional configuration with the wall 28 and lid 20 being joined by a conventional radius (e.g., 0.069 inches) without the need for a special configuration to promote sealing between the cap 18 and the container 12.

The container 12 is a bottle 34 having a neck 36 with external engaging means, such as helical threads 38, for engagement with the internal engaging means of the cap 18 for closing and opening the bottle 34. The bottle 34 also includes a rim 40 at its uppermost end defining an opening 42 for receiving and discharging the contents of the bottle 34. See Figures 1-3. The rim 40 has an upper horizontal surface 44, an inner adjacent depending annular surface 48 which defines the opening 42 and an outer adjacent, depending annular surface 46 below which are the external helical threads 40. The adjacent intersecting portions of the rim surfaces 44, 46 and 48 are rounded and typically the outer convex radius of about 0.028 inches. The sealing areas of the rim 40 generally include its too surface 44 (top or rim seal), its outer rounded convex corner 50 (corner seal) and its outer surface 48 (outer seal).

The illustrative plastic liner 14 of the invention generally is a movable liner, and includes an upper member in the form of a disk 52 having a thin circular core 53 about which is a thicker integral annular ring 54. The liner 14 also includes a depending member in the form of a bead 56 integral with and about the periphery 58 of the disk 52. With respect to the disk 52, its core 53 is made thinner to save plastic material where it is not needed for sealing. Correspondingly, the width or breadth of the outer thicker annular ring 54 extends from the core 53 across the bottle rim 40 to the outer periphery 58 of the disk 52. Also, the diameter of the disk 52 is greater than the diameter of the rim 42 of the bottle 34 and the inner diameter of the threads 26.

With respect to the depending member of the liner 14, the bead 56 is a curvilinear in the form of a solid semi-circle, wherein the inner portion 60 is concave and intersects with the underside 59 of the disk 52 in a radius which allows the bead 56 to fully engage the outer convex corner 50 of the rim 40 without any space therebetween.

The cap 18, the bottle 34 and the plastic liner 14 can be formed by conventional compression or injection molding techniques. Thereafter, the plastic liner 14 is insertable into and floats or moves within the chamber 32 of the cap 18. Once the bottle 34 is filled, it is ready for capping. The cap 18 is capped onto the bottle 34, wherein the tamper evident band

26 engages the ring 29 of the bottle 34. See Figures 2 and 3. Until such engagement is complete, the liner 14 may float in the lower portion of the chamber 32. Once the liner 14 is engaged by the bottle rim 40, it will moved upwardly until it engages the upper and concave portion of the skirt wall 28. See Figure 2. As the engagement between the cap 18 and the bottle 34 continues, the disk 52 begins to deform with its outer periphery fully engaging the concave portion of the wall 28 while the liner 14 is moved up and into the underside of the lid 20. In doing so, the bottle rim 40 compresses the thickened portion 54 against the lid 20 and the bead 56 between the cap 18 and rim 40 to fully mate with the corner 50 and the outer portion 48 of the rim. See Figure 3. As illustrated, the liner 14 with its outer thickened portion formed by the adjacent and intersecting portions of the upper ring 54 and the depending bead 56 provide rim, corner and outer seals 40, 50 and 48, respectively. Even if the lid 20 of the cap 18 flexes upwardly or downwardly, at least the corner seal 50 will be maintained to prevent leakage from or into the contents of the bottle 34.

Upon the initial opening of the bottle 34, the tamper evident band 26 separates from the skirt 22, as generally described in United States No. 4,709,824 and European Patent

Application No. 91903006.4, to thereby indicate that the bottle 34 has been opened. In removing the cap 18 from the bottle 34, the compressive forces on the plastic liner 14 are released. In the removed cap 18, the plastic liner 14 once again floats DΓ is movable, ready to provide its sealing properties upon the closing of the bottle 34. In this preferred embodiment, the length or diameter of the disk 52, illustratively can be from about 0.70 to about 3.1 depending on the size of the cap 18 The thickness of the disk's thinner central core 52, illustratively can be about 0.010 inches. While the thickness of the thicker annular ring 54, illustratively can be in the range of from about 0.018 to 0.035 inches. It is also preferred that the thin central core 53 and the thicker annular ring 54 of the liner 14 are in the same plane. The length or breadth of the depending bead 56 can be in the range of from about 0.10 to 0.50 inches. The thickness or radius of the bead 56, illustratively can be in the range of from about 0.035 to about 0.070 inches. Also, the radius of the inner concave portions of the beads 56, typically can be from about 0.025 inches to about 0.050 inches.

The plastic liners of the invention can be made from any suitable polymer that can flow and conform to the irregularities of the top of a container. Generally suitable are poly vinyl chloride, low density polyethylene (LDPE), and ethylene-vinyl acetate copolymers.

These polymers also can include other substances which act as barriers and scavengers for the contents of the containers, such as flavors, carbonation, etc.

Cap sizes typically range from about 18 mm to about 80 mm and bottle and/or container sizes range from about 8 oz to 128 ounce capacity. Larger capacity containers are also suitable for the practice of the invention as are smaller vials and other containers.

Useful plastics which can be used for forming the caps of the invention include polypropylene, polyethylene and other semi-rigid to rigid plastic materials.

The caps and floating liners of the present invention may be used to close and seal a wide variety of containers for a wide variety of foods, including: beverages, including carbonated soft drinks and pasteurized beverages such as beer; food, especially those where container sealing performance is critical, including oxygen sensitive ones such as mayonnaise, peanut butter and salad oil, and including corrosive ones such as vinegar, lemon juice; and household chemicals, including bleaches and detergents, drugs and cosmetics and other products requiring the highest integrity seal and reseal under the widest range of distribution and use conditions.

Referring now to the other illustrative embodiments of the floating plastic liners of the present invention, there is shown in Figure 4, a liner 64 similar to the liner 14 of Figures 1-3, except for the configuration of the annular depending bead 66. In this embodiment, the bead

66 includes an outer peripheral surface 68 which is linear or vertical and which is contiguous with outer vertical surface 70 of the liner 64, and a truncated triangular end or tip 72. The tip 72 has angular outer surface 74 forming an acute angle with the outer bead surface 68, an essentially flat lowermost or end surface 76, and an angular inner surface 78 forming an obtuse angle with the ring 54. In Figure 5, there is shown a floating or movable plastic liner 80 of the present invention including a depending annular bead 82 at the periphery of the ring 54 having a vertical outer surface 84, a straight or horizontal lowermost surface 86, and an inner curvilinear surface 88 which extends into the ring 54.

Figures 6 and 7 disclose liners 90 and 92 of the present invention, wherein the thinner core 52 has been eliminated, and wherein the disks 52 are of uniform thickness along their entire lengths. In addition, Figures 6 and 7 illustrate that the disks 52 can be of different thicknesses.

Referring now to Figures 8 and 9, there is shown liners 96 and 98 which are similar to Figures 6 and 7, in that the liners 96 and 98 have a uniform thickness along their entire lengths. In these embodiments, however, the outer depending beads 100, generally are triangular or pie shaped in cross section and include an inwardly and downwardly sloping surfaces 102 extending from and integral with the outer vertical surfaces 104 of the disks 52 of the liners 96 and 98. In Figure 8, the surface 102, illustratively iorms an acute angle of about 19 degrees and in Figure 9, the acute angle is about 21 degrees. Correspondingly, the inner surfaces 106 of the beads 100 are curvilinear having a radius which can be about 0.040 inches and of about 0.050 inches, respectively. As illustrated, the inteisecting outer and inner surfaces 102 and 106 form at its apex a depending point or peak 108.

In the embodiment illustrated in Figure 10, the liner 110 includes a depending peripheral bead 112 that is generally triangular in cross section with an inwardly and downwardly sloping annular and linear surface 114 which extends from the upper surface 116 of the liner 110. The inner surface 118 of the bead 112, on the other hand, is curvilinear. As in Figure 8 and 9, the surfaces 114 and 1 16 of the bead 112 intersect to form at its apex a depending peak or point 128. In this embodiment, however, the outer and inwardly sloping surface 114 also can act as a vent to facilitate the earlier release of c<_ ntained gases upon the initial opening of the cap 18. This is due to the fact that the described surface 118 opens the seal sooner as the cap 18 and the bottle 34 are disengaged. In practice the floating or movable plastic liners of Figures 4-10 generally operate and function similar to the plastic liner 14 of Figures 1-3 to seal against leakage from or onto the contents of the containers, bottles, etc.

The floating plastic liners 14, 64, 80, 90, 92, 96, 98 and 1 10 of the illustrative embodiments of the present invention also can maintain their sealing properties and provide extra cushioning for impact resistance, e.g., if the container or bottle .34 is dropped from the supermarket shelf and the cap 18 flexes. The pre-configurations and positioning of the beads 56, 66, 82, 100 and 110 also provide sealing of the liner system throughout closure doming and stacking, i.e., when the top of the cap 18 is flexed up or down. For example, the compressed sealing area of the described pre-configured thickened peripheral portions of the plastic liners do provide one or more seals (rim, corner and outer seals) depending what is occurring to the skirt due to the contents of the bottle, or due to external conditions acting on the closure.

The invention in its broader aspects is not limited to the specific described embodiments and departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

Claims

What is claimed is:

1. A closure for a container having a neck with a rim which define an opening, comprising:

(a) a lid; (b) an annular skirt depending from said lid; and

(c) a deformable liner of plastic movable within said closure, including an upper member adjacent said lid having a breadth greater than the breadth of the rim, and a pre- configured member depending from the periphery of said upper member, wherein said members are adapted to provide a thickened portion of compressible plastic at and about the rim when said cap is closed on the neck of the container and said plastic liner has been deformed between said lid of the closure and the rim of the container, to thereby provide a liner which seals against leakage from and into the container.

2. A liner of compressible plastic insertable and movable, within a cap having a lid and depending skirt for a container having a neck with a rim which defines an opening, said liner comprising: an upper member having a breadth greater than the breadth of the rim, and a pre- configured member depending from the periphery of said upper member, wherein said members are adapted to provide a thickened portion of compressible plastic at and about the rim when said cap is closed on the neck of the container and said plastic liner has been deformed between said lid of the closure and the rim of the container, to thereby provide a liner adapted to seal against leakage from and into the container.

3. A cap for a container having a neck with a rim which define an )pening, comprising:

(a) a lid;

(b) an annular skirt depending from said lid, which engages the rim for opening and closing of the container; and

(c) a plastic deformable liner movable within the cap, incl ding an upper circular disk having a diameter greater than the outer diameter of the rim. and an annular bead depending from the periphery of said disk, wherein said bead and ad icent disk portions are adapted to provide a thickened portion of compressible plastic at and about the container rim when said cap is closed on the neck of the container and said plastic liner has been deformed 10

between said lid of the cap and the rim of the container, to thereby provide a liner which seals against leakage from and into the container.

4. A plastic liner insertable and movable within a cap having a lid and a depending skirt for a container having a neck with a rim which defines an opening, said liner comprising: an upper circular disk having a diameter greater than the outer diameter of the rim and an annular bead depending from the periphery of said disk, wherein said bead and adjacent disk portion are adapted to provide a thickened portion of compressible plastic at and about the container rim when said cap is closed on the neck of the container and said plastic liner has been deformed between the lid of the cap and the rim of the container, to thereby provide a liner which seals against leakage from and into the container.

1 1

5. The plastic liner of claims 3 and 4, wherein said bead has a cross-sectional configuration adapted to provide top, corner and outer seals with the rim of the bottle upon compression of said liner.

6. The plastic liner of claims 3 and 4, wherein said bead and the adjacent peripheral portion of said disk have a cross-sectional configuration which is adapted to fully mate with and about the rim of the bottle upon compression of said liner.

7. The plastic liner of claims 3 and 4, wherein said bead has a cross-sectional configuration which essentially is a solid semi-circle with the inner portion thereof intersecting with the underside of said disk in a radius which allows said bead to fully engage the outer corner of the rim of the bottle without any space therebetween upon compression of said liner.

8. The plastic liner of claims 3 and 4, wherein said bead has a cross-sectional configuration which includes a truncated triangular portion at its lowermost end.

9. The plastic liner of claims 3 and 4, wherein said bead includes a vertical outer surface, a horizontal lowermost surface and an inner curvilinear surface which extends into the underside of said disk.

10. The plastic liner of claims 3 and 4, wherein said bead has an essentially triangular cross-sectional configuration with its apex at the lowermost end.

11. The plastic liner of claims 3 and 4, wherein said bead is essentially triangular in cross- section with an inwardly and downwardly extending surface which extends from the upper surface of said disk, an inner surface which is curvilinear and intersects with the underside of said disk, and an apex positioned at its lowermost end.

12. The plastic liner of claims 3 and 4, wherein said disk includes an inner thin core and an annular ring which is thicker than said core and which extends from said core to the outer periphery of said disk.

13. The plastic liner of claims 3 and 4, wherein said disk has a uniform thickness.