Tamper-evident seal for a container

Abstract

A container is provided which includes body having a top portion and a bottom portion. Each of the top portion and bottom portion have lips which are affixed together at a first location. A perforation line is made in at least one of the top and bottom lips. The perforation line is between the first location and the container body. An adhesive member covers a portion of the perforation line between the top and bottom lip so that the adhesive member may be pulled through the perforation line to gain access inside the container body.

Description

FIELD OF THE INVENTION

1. Technical Field

The present invention relates to an improved container. More particularly, the present invention relates to a tamper-evident seal for a container which is easily opened.

2. Background of the Invention

Plastic containers for distributing food and consumer goods are in common use. Such containers, when used for food, extend the shelf life of perishable products, resulting in savings to the food industry and fresher food to the consumer. One concern of consumers is the integrity of the food within the container. Consumers want to be assured that the food has not been tampered with prior to purchasing. It is desirable to provide such containers with a seal and a means to easily identify when those containers have been opened. Tamper evident seals for plastic containers are known in the art. Various prior art systems are available to provide evidence that a container has not been opened. One prior art method is to wrap the container with a plastic band which must be cut to gain access to the container. Other, more sophisticated methods are also known. For example, two such methods are shown in United States published patent applications 2005/0184070 A1 and 2007/0045317 A1, the disclosures of which are incorporated herein by reference. Containers for non-food consumer products also may require tamper-evident seals so that consumers can be assured that they are receiving new products in factory condition.

A tamper-evident seal is needed which is easy to open, inexpensive to produce and which provides ready evidence that the seal has been broken.

SUMMARY OF THE INVENTION

The present invention can be used in connection with a variety of plastic food and consumer product containers. The plastic used could be thermoplastic material such as polyethylene terephthalate (PETE), polystyrene, polypropylene and polyethylene, or other similar plastic material. The material may be, for example, from 0.010 to 0.050 inches thick. Such containers are typically made by thermoforming in a mold. The container could be of various sizes and configurations depending on the purpose of the container. The container could be used for food, such as baked goods, fruit, vegetables, meat, cheese, salads, eggs and other food items. The container could also be used for retail products such as batteries, compact disks, razors, electronics, hardware, tools and other products.

In one embodiment, the invention employs a single-piece thermoformed container consisting of a bottom portion and a top portion joined by a hinge. In another embodiment, the container includes separate top and bottom portions which may be attached to one another. Preferably, the top and bottom portions are attached to one another near the edges through ultrasonic welding, heat staking, stitch welding or similar methods. If the top and bottom portions are joined by a hinge, then the welding can be on the side of the container opposite the hinge. If the top and bottom are separate, two or more sides can be attached to one another by ultrasonic welding, heat staking, stitch welding or similar methods.

In either case, the top and bottom portions each have at least one lip extending out from the container body. A series of portions of weakened material or aligned cuts, such as perforations are disposed in one of the top or bottom lip portions. The lip can have one or two perforation lines. The perforations can be made with a steel rule die. In one example die, the teeth are spaced at 30 teeth per inch. The perforations are between the weld line and the body of the container on at least one side of the container. The perforation line is covered with an adhesive member such as tape, preferably, polypropylene or PETE tape, with, for example, an aqueous based acrylic or rubber based adhesive. One suitable tape is filament reinforced tape such as Scotch Tear Tape sold by 3M Corporation of St. Paul, Minn. The adhesive member is placed between the top and bottom lips and a portion of the adhesive member projects out from between the lips.

To gain access to the container body, the adhesive member is pulled through the perforation line, breaking the perforations. The portions of the lips which are affixed to one another remain affixed, but the container may be opened because the perforation line is between the part of the lip which is affixed to the other lip and the container body. When the perforation line is broken it is evident that the container has been opened.

The top portion and bottom portion can each have second lips which extend from the container body. These second lips can also be joined by welding or other similar methods and can include one or two perforation lines covered by an adhesive member, in the manner as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments and applications of the invention are illustrated by the attached non-limiting drawings. The attached drawings are for purposes of illustrating the concepts of the invention and may not be to scale.

FIG. 1 is a side elevation view of a container according to one embodiment of the present invention;

FIG. 2 is a bottom plan view of the container of FIG. 1;

FIG. 3 is a top plan view of the container of FIG. 1;

FIG. 4 is an isometric view of the container of FIG. 1 after closing and sealing the container;

FIG. 5 is a cross-sectional view of the container of FIG. 4 taken along line 5-5 in FIG. 4;

FIG. 6 is a cross-sectional view of the container of FIG. 4 taken along line 6-6 in FIG. 4;

FIG. 7 is perspective view of another embodiment of the present invention;

FIG. 8 is a top plan view of the invention of FIG. 7;

FIG. 9 is a perspective view of another embodiment of the present invention showing the top portion separated from the bottom portion;

FIG. 10 is a perspective view of a portion of the top portion of the invention of FIG. 9;

FIG. 11 is a perspective view of a portion of the bottom portion of the invention of FIG. 9; and

FIG. 12 is a top plan view of the invention of FIG. 9 in the closed position.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Throughout the following description specific details are presented to provide a more thorough understanding to persons skilled in the art. However, well-known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

Preferred embodiments of the present invention are described with reference to FIGS. 1-12. FIG. 1 shows one particular shape for a container 10, it being understood that the container 10 is shown in this shape for illustration purposes only and that the container could take on a wide variety of shapes, sizes and configurations. FIG. 1 shows the container 10 in an open orientation having a top portion 12 and a bottom portion 14. The top portion 12 has a lip 20 extending away from the container top body 16. The bottom portion 14 also has a lip 22 extending from the container bottom body 18. The top portion 12 can have reinforcing ribs 24 and the bottom portion 14 can also have reinforcing ribs 26. A hinge 27 is provided between the container top body 16 and the container bottom body 18.

As shown in FIG. 6, the bottom portion 14 has an upwardly extending wall 28 and the top portion 12 has a sidewall portion 30. When the container is closed, the upwardly extending wall 28 presses against the sidewall portion 30 to hold the container closed. Other configurations for interlocking parts are commonly used and will be readily apparent to those skilled in the art.

Reference is now made to FIGS. 2 and 3. It will be understood that while certain features are described in association with the lip 20, this is done for illustration purposes, and that those features could be associated with lip 22 instead. In FIGS. 2 and 3, the lip 20 on the top portion 12 includes a perforation line 34 extending lengthwise along the lip 20. The perforation line 34 consists of a series of aligned cuts or weakened portions of the lip 20. In one example embodiment, the cuts or weakened portions may be between 20 to 40 per inch, separated by, for example, material which is 0.012 inches long, although various other dimensions of perforations will work. Although shown as straight, the perforation line may have other geometries. The perforation line 34 is covered with an adhesive strip 36. Preferably, the lip 20 terminates at both ends in tabs 40 and 42, which are removably attached to the lip 20. Adhesive strip 36 extends, preferably, to both tabs 40 and 42. Adhesive strip 36 is preferably constructed of filament reinforced tape, but other adhesive members can be used.

FIG. 4 shows the container 10 in the closed configuration. The lips 20 and 22 have been affixed together by a know technique such as ultrasonic welding, heat staking or other techniques. For illustration purposes, the lips 20 and 22 are shown as welded together by welds 50. The welds may be in the range of 0.06 inches to 0.1 inches in diameter. The welds may be separated from one another by spaces of 0.12 inches to 0.19 inches, for example. Other dimensions for the size of the welds and the spacing between the welds will work. When closed, the container 10 has adhesive strip 36 between lips 20 and 22.

The perforation line 34 must be broken to access the contents of the container 10. The perforation line 34 can be broken by grasping tab 40 or 42 and pulling adhesive strip 36 through the perforation line 34. FIG. 4 shows tab 40 separated from the lip 20 and pulled partially through perforation line 34. FIG. 5 illustrates the partial opening of container 10 as well. Because the perforation line 34 is between the welds 50 and the container top body 16, a portion of the lip 20 will remain attached to the lip 22 as the perforation line 34 is broken. Once the perforation line 34 is broken, the container 10 can be opened.

As shown in FIG. 7, instead of being joined by a hinge, the top portion 112 and bottom portion 114 of container 110 could alternatively comprise two separate pieces. The top portion 112 has a lip 120 extending away from the container top body 116. The bottom portion 114 also has a lip 122 extending from the container bottom body 118. The top portion 112 can have reinforcing formations 124 and the bottom portion 114 can also have reinforcing formations 126. A hinge 127 is created by providing a perforation line 129 on the lip 160 inside of weld line 131, although other hinge mechanisms are possible.

As shown in FIG. 8, the lip 120 on the top portion 112 includes two perforation lines 134 and 135 extending lengthwise along the lip 120. The perforation lines 134 and 135 consist of a series of aligned cuts or weakened portions of the lip 120. The perforation lines 134 and 135 are shown as straight, but may have other geometries. The perforation lines 134 and 135 are covered with an adhesive strip 136. Preferably, the lip 120 terminates at both ends in tabs 140 and 142, which are removably attached to the lip 120. Adhesive strip 136 extends, preferably, to both tabs 140 and 142. Adhesive strip 136 is preferably constructed of filament reinforced tape, but other adhesive members can be used.

As shown in FIGS. 7 and 8, the lips 120 and 122 have been affixed together by ultrasonic welding, heat staking or other techniques. Ultrasonic welds 150 are shown as an example method of affixing the lips together. When closed, the container 110 has adhesive strip 136 between lips 120 and 122. Lips 160 and 162 have also been affixed together by, for example, ultrasonic welds 151.

As with the embodiment shown in FIG. 4, the perforation lines 134 and 135 must be broken to access the contents of the container 110. The perforation lines 134 and 135 can be broken by grasping tab 140 or 142 and pulling adhesive strip 136 through the perforation lines 134 and 135.

FIGS. 9-12 show another example embodiment. As shown in FIGS. 9 and 12, the top portion 212 and bottom portion 214 of container 210 could comprise two separate pieces. The top portion 212 has a lip 220 extending away from the container top body 216. As best seen in FIG. 11, the bottom portion 214 also has a lip 222 extending from the container bottom body 218. The top portion 212 can have reinforcing formations 224 and the bottom portion 214 can also have reinforcing formations 226. The top portion 212 has a lip 260. The bottom portion has a lip 262.

As shown in FIGS. 9 and 10, the lip 220 on the top portion 212 includes two perforation lines 234 and 235 extending lengthwise along the lip 220. The perforation lines 234 and 235 consist of a series of aligned cuts or weakened portions of the lip 220. It is not necessary that the perforation lines 234 and 235 be straight. The perforation lines 234 and 235 are covered with an adhesive strip 236. Preferably, the lip 220 terminates at both ends in tabs 240 and 242, which are removably attached to the lip 220. Adhesive strip 236 extends, preferably, to both tabs 240 and 242. Adhesive strip 236 is preferably constructed of filament reinforced tape, but other adhesive members can be used.

The lips 220 and 222 have been affixed together by ultrasonic welding, heat staking or other techniques. Ultrasonic welds 250 are shown for as an example method of affixing the lips together. When closed, the container 210 has adhesive strip 236 between lips 220 and 222. As shown in FIG. 12, lips 260 and 262 have also been affixed together by, for example, ultrasonic welds 251. Lip 260 also has two perforation lines 264 and 265. The perforation lines 264 and 265 are covered with an adhesive strip 270. The lip 260 terminates at tabs 266 and 268.

All perforation lines 234, 235, 264 and 265 must be broken to access the contents of the container 210. The perforation lines 234 and 235 can be broken by grasping one of the tabs 240 and 242 and pulling adhesive strip 236 through the perforation lines 234 and 235. Similarly, the perforation lines 264 and 265 can be broken by pulling on tabs 266 or 268 to pull adhesive strip 270 through the perforation lines 264 and 265.

It is to be understood that the exemplary embodiments are merely illustrative of the present invention and that many variations of the above-described embodiments can be devised by one skilled in the art without departing from the scope of the invention. It is therefore intended that all such variations be included within the scope of the following claims and their equivalent.

Claims

1. A container comprising:

a container body having a top portion and a bottom portion, the top portion and bottom portion forming a connection around their periphery;

a top lip extending from the top portion;

a bottom lip extending from the bottom portion, a portion of the top lip affixed to a portion of the bottom lip at a first location;

a perforation line in at least one of the top and bottom lips, the perforation line between the first location and the container body,

an adhesive member covering a portion of the perforation line between the top and bottom lip, whereby the adhesive member may be pulled through the perforation line to gain access inside the container body.

2. The container of claim 1 wherein the container body further includes a hinge joining the top portion and the bottom portion.

3. The container of claim 1 further including a second perforation line in at least one of the top and bottom lips, the second perforation line between the first location and the container body and wherein the adhesive member covers a portion of the perforation line and the second perforation line.

4. The container of claim 1 wherein the top and bottom lips are ultrasonically welded together.

5. The container of claim 1 wherein the top and bottom lips are heat-staked together.

6. The container of claim 1 wherein the perforation line comprises a weakening of a selected one of the top or bottom lips.

7. The container of claim 6 wherein the top or bottom lip other than the selected one lacks a perforation line.

8. The container of claim 6 wherein the weakening comprises a series of aligned cuts in the selected lip.

9. The container of claim 8 wherein the aligned cuts penetrate completely through the selected lip.

10. The container of claim 1 wherein the adhesive member extends beyond one of the top and bottom lips.

11. The container of claim 10 wherein the portion of the adhesive member which extends beyond one of the top and bottom lips is attached to a grasping tab of one of the top and bottom lips.

12. The container of claim 1 wherein at least one of the top and bottom portions are made from thermoplastic material.

13. The container of claim 1 wherein at least one of the top and bottom portions are made from polyethylene terephthalate.

14. The container of claim 1 wherein at least one of the top and bottom portions are made from polystyrene.

15. The container of claim 1 wherein at least one of the top and bottom portions are made from polypropylene.

16. The container of claim 1 wherein at least one of the top and bottom portions are made polyethylene.

17. The container of claim 1 wherein the adhesive member is made from polypropylene.

18. The container of claim 1 wherein the adhesive member is made from polyethylene terephthalate.

19. A container comprising:

a container body having a top portion and a bottom portion, the top portion and bottom portion forming a connection around their periphery;

a first top lip extending from the top portion;

a first bottom lip extending from the bottom portion, a portion of the first top lip affixed to a portion of the first bottom lip at a first location;

a first perforation line in at least one of the first top and first bottom lips, the first perforation line between the first location and the container body;

a second perforation line in at least one of the first and second bottom lips, the second perforation line between the first location and the container body;

a second top lip extending from the top portion;

a second bottom lip extending from the bottom portion, the second top lip affixed to a portion of the second bottom lip at a second location;

a third perforation line in at least one of the second top and second bottom lips, the third perforation line between the second location and the container body;

a fourth perforation line in at least one of the second top and second bottom lips, the fourth perforation line between the second location and the container body;

a first adhesive member covering a portion of the first and second perforation lines between the top and bottom lips, whereby the adhesive member may be pulled through the first and second perforation lines to gain access inside the container body; and

a second adhesive member covering a portion of the third and fourth perforation lines between the second top and second bottom lips, whereby the second adhesive member may be pulled through the third and fourth perforation lines to gain access inside the container body.