WO1985002165A1

WO1985002165A1 - Tamper indicating cap

Info

Publication number: WO1985002165A1
Application number: PCT/US1984/001865
Authority: WO
Inventors: Wendell J. Manske; Curtis L. Larson
Original assignee: Minnesota Mining And Manufacturing Company
Priority date: 1983-11-21
Filing date: 1984-11-16
Publication date: 1985-05-23
Also published as: EP0164370A1

Abstract

A tamper indicating cap liner (16, 40) for a translucent cap (10, 55) which is adapted to be joined to the cap by a deposit of adhesive and to the container (13, 59). Upon the adhering of the liner to the cap and container, relative movement causes the liner joined in the cap to rupture and tear to indicate tampering or that the container has been opened.

Description

Description Tamper Indicating Cap

Technical Field

This invention relates to an improvement in liners for bottle or other container caps which will provide a visual indication at the point of purchase or before use if the cap has been previously removed, and in one aspect, to an improved tamper-resistant cap liner construction.

Background Art This invention relates to an improvement in a container seal which fits beneath the cap to afford the consumer the opportunity to readily determine whether or not the cap has been previously opened or tampered with since the container left the manufacturer or packaging company. The need for barriers within a cap to seal the container has become required but the cap must be removed at the point of purchase to determine whether or not there was any tampering with this inner seal. The present invention provides a tamper-indicating inner seal for caps having at least a portion of the top thereof being translucent by which one can readily tell whether or not the cap has been tampered with at the point of purchase.

The need for preventing one from readily removing the seal of a container and replacing the same without detection has existed for some time. One prior patent relating to a rupturable container closure which is used in the seal for a container is shown in U.S.A. Letters Patent 2,131,774, issued October 4, 1938 to Waring. This patent discloses a cap which is used to force a plate against a liner or gasket to seal the top of the bottle. Between the plate and the cap is a rupturable disc of fibrous or other suitable rupturable material having impressed thereon a safety design of a type making the duplication or counterfeiting of such a disc as difficult as possible. It is desirable to bond the disc to the plate by some suitable adhesive or cement. The cap however is provided with prongs which, after the cap is in place, are forced downward to penetrate the rupturable disc in areas above a groove formed in the metal plate. When opening the container it is merely necessary for the user to impart a reverse turning movement to the closure. During the first portion of this movement the metal shell will turn independently of the packing liner or gasket, the plate and the rupturable disc and the prongs will move along the groove 19 and tear the material of the disc forming jagged and irregular tears in the disc. After the prongs have once been placed through the disc, it would be extremely difficult to remove the cap in a manner which could avoid detection. The invention of the present application provides a rupturing and tearing of an inner seal upon rotation of the cap in relationship to the container in much the same manner, but, adhesives are used to adhere the rupturable liner to the inside of the cap such that the relative movement causes the tearing and a very visible indication of tampering with the closure.

The present invention has the advantage of being formed for use with normal cap lining equipment and with induction sealing equipment which seals the existing cap liner materials to the container at the time the containers are filled.

Disclosure of Invention

The present invention provides a tamper-indicating cover member suitable for use on a wide variety of containers comprising a translucent cap, i.e. at least a portion being translucent or transparent, and an inner seal placed in the cap for sealing to the container after the same has been filled. A deposit of adhesive and an adhesive layer adhere the cap, inner seal and container together in such a way that relative rotation between the cap and container ruptures the inner seal in a manner to be visible through the cap. The inner seal comprises a membrane of rupturable material adapted to be sealed to the inner surface of the cap and secured to the upper surface of the neck of the container. After the container is filled the cap and inner seal will be placed on the container. Suitable means will be utilized to seal the inner seal to the container about the opening thereof and also to seal the rupturable disc of the inner seal to the cap. The adhesive between the rupturable disc and the disc of seal material, which is adhered to the container, will adhere the rupturable disc, cap and container together in a manner such that the rupturable disc will tear as the cap moves relative to the container. The same rupturing occurs with a translucent polymeric cap which is threaded or snapped on or off of a rib or shoulder formed around the open end of the container.

Additionally a separate disc can be sealed to the cap and sealed by a spot of adhesive or narrow band of adhesive to the inner seal which is adhered to the neck of the container.

A laminated container seal material preferably forms the second membrane and comprises a metal vapor barrier in the form of a metal foil adhered by an adhesive to a tough clear polymeric material which is further coated by a sealing layer to adhere the polymeric film to the container. The sealing layer could comprise a thin coating of clear polyethylene. Other seal materials may be used however such as a polymeric film on treated paper.

The rupturable disc is preferably formed of a thin layer of a metal foil such as aluminum which is coated with a heat sealable layer such as polyethylene. The rupturable disc and the vapor barrier layer of the inner seal would preferably be printed or coated with different colored materials to readily expose in the ruptured areas of the rupturable disc the color or printing on the vapor barrier layer indicating that the container has been opened. The rupturable disc may comprise a paper disc or a disc of film or foil perforated to rupture easily.

A thin washer or gasket may be placed between the rupturable disc and the interior surface of the top of the cap. This gasket may have a pressure sensitive or thermoplastic adhesive coated thereon to adhere it in place on the cap. The rupturable layer would then be adhered to this gasket such that upon rotation of the cap, gasket and rupturable disc relative to the container and seal adhered to the container, the rupturable disc would be torn by the adhesive joining the rupturable disc to the seal.

Brief Description of Drawing

This invention will be further described with reference to the accompanying drawing wherein:

Figure 1 is a top view of a cap and liner with portions thereof broken away to illustrate interior layers;

Figure 2 is a cross sectional view showing the construction of the web of liner material from which the cap liners are die cut;

Figure 3 is a vertical sectional view of a cap and liner constructed in accordance with the present invention sealed to a container;

Figure 4 is an exploded view of the cap and parts of the cap liner and container;

Figure 5 is a diagrammatic top view of the cap after it has been opened;

Figure 6 is a vertical sectional view of the cap as it is opened;

Figure 7 is an exploded view of another embodiment with the cap and liner in vertical section to illustrate interior features;

Figure 8 is a fragmentary top perspective view showing the cap of Figure 7 turned and the liner ruptured;

Figure 9 is a diagrammatic sectional view of a further embodiment of a cap and liner constructed in accordance with the present inveniton; and Figure 10 is a diagrammatic sectional view of a cap, liner and container constructured according to a further embodiment.

Best Mode for Carrying Out the Invention The present invention provides an improved cap and liner which when sealed to a container with the cap attached will provide a readily detectable tamper-indicating closure for the container. As illustrated in the attached drawing, where similar numerals on the various figures illustrate identical parts, a cap 10 is formed of a translucent polymer and having a top and connecting side walls with internal threads 11 to mate with the threads 12 provided on the outer surface about the neck and opening of a container 13. A cap liner is placed inside of the cap and this is usually done by the cap manufacturer. The caps are supplied to the packager with the liner placed in the cap. The cap liner is generally designated by the reference numeral 15 and comprises a membrane or disc 16 of rupturable material coated with a sealing layer, a membrane or disc 20 of a laminated container seal material and a spot, strip or other deposit of adhesive 21 adhering the disc 16 to the disc 20.

As illustrated in Figure 2 the web from which the cap liner 15 is die cut comprises a layer 22 of metal foil, such as dead soft aluminum, which may be 0.025 mm (0.001 inch) in thickness, although foils from 0.05 mm (0.002 inch) and thinner have been used with success. The layer 22 has a top coating 23 of a heat sealable material such as polyethylene. The layer 22 and coating 23 define the disc 16. Printed messages or a color, other than the silver finish of the foil, may be applied. A deposit 21 of adhesive is used to join the layer 22 to the next layer 25 of the web. The adhesive may be placed in a random dot pattern on the web or as a narrow strip. The adhesive is preferably a spot of Jet Melt 3764 adhesive available from Minnesota Mining and Manufacturing Company, St. Paul, MN, U.S.A. This adhesive is a hot melt adhesive or spots of a strong pressure-sensitive adhesive could be substituted. The web further comprises a layer 25 of a metal foil to provide a ductile vapor impermeable layer, and such material may preferably be dead soft aluminum. The layer 25 is laminated by a layer of adhesive 26 to a tough thermoplastic clear film layer 28 such as polyethylene terephthalate having a thickness of 0.012 mm (0.0005 inch). The adhesive 26 for bonding the polyethylene terephthalate (polyester) layer to the foil layer 25 is preferably a polyurethane or an adhesive from the nitrile or vinyl family. Laminated to the film layer 28 is a sealing layer 29 having a desired thickness of about 0.038 mm (0.0015 inch). An example of the sealing layer 29 may be polyethylene.

The cap liner may be die cut from the web as above described and placed in the cap 10. A washer type gasket 30 can be added between the inner surface of the top of the cap 10 and the sealing layer 23 of the rupturable disc 16. The gasket 30 can be formed of a 1.0 mm (0.04 inch) polyolefin foam such as "4310 "Cap Seal II" film, available from Minnesota Mining and Manufacturing Company, St. Paul, MN, U.S.A., which is provided with a layer of pressure-sensitive adhesive. The pressure-sensitive adhesive adheres the gasket 30 to the interior of the cap 10.

As illustrated in Figures 5 and 6, rotation of the cap 10 in an unwinding direction, with the gasket 30 and disc 16 fixed to the inner surface of the cap 10 and the disc 20 fixed about the opening of the container 13 and with the two discs adhered by the adhesive 21, causes the disc 16 to rupture or tear an opening in the same as illustrated at 33. Continued relative rotation of the cap and container will result in the disc 16 being torn and separated from the disc 20, as illustrated in Figure 6 providing, through the translucent cap 10 a clear visual indication the cap has been previously opened. This results from rotation or separation of the cap with relationship to the container.

The disc 16 may be color coated or printed with suitable ink to bear a desired message or the manufacturer's logo. The layer 25 is colored or printed with indicia of contrasting color to expose the contrasting color through the torn membrane or expose the message "OPENED" for example, which is an indication of cap movement.

The present invention provides a cap liner which provides a tamper indication and the use of metal, i.e., aluminum foil for the rupturable layer 22, and for layer 25 allows the sealing layers 23 and 29 to be a normally nontacky material activated to have adhesive quality when the assembled cap, liner and container are exposed to energy to inductively heat the foil layers to activate the sealing layers.

The adhesive bonds must be sufficient between the disc 16 and the cap, between the disc 16 and disc 20, and between the disc 20 and the container that they exceed the strength of the disc 16 whereby the disc 16 will tear upon rotation of the cap in relationship to the container. Thus, other adhesives may be utilized which will achieve the desired bond when the cap is turned onto the container or when the liner is pressed into the cap.

The disc 20 is formed to have an internal strength greater than the disc 16 so that, the visible disc is ruptured upon the relative rotational movement. The embodiment of Figure 7 comprises a cap 10 with threads 11 to mate with threads 12 of container 13. The cap 10 is provided with an annular rib 14 positioned opposite the upper surface of the neck of the container 13. The rib has a narrow edge for concentrating sealing heat and pressure.

A cap liner 40 comprising a disc 41 of rupturable material coated with a sealing layer 42 is placed in the cap 10. A deposit of adhesive 44 is placed in the cap 10 for adhering the disc 41 to the interior surface 45 of the top of the cap 10. At least a portion of this top must be translucent. The web from which the cap liner 40 is die cut comprises the layer 41 of aluminum foil which may be 0.025 mm (0.001 inch) in thickness, although foils from 0.05 mm (0.002 inch) and thinner have been used with success. The sealing layer 42 is a heat sealable material such as polyethylene. Indicium, formed by a layer 46, preferably an ink, is printed on the surface of the layer 41 opposite the adhesive coating. The indicium 46 may alternatively be a layer of colored material. The deposit or spot 44 of adhesive may be placed in a random dot pattern on the web from which the liner 40 is cut. The adhesive is preferably a spot of Jet Melt 3764 adhesive available from Minnesota Mining and Manufacturing Company, St. Paul, MN, U.S.A. This adhesive is a hot melt adhesive. Spots or strips of a strong pressure-sensitive adhesive could be substituted.

When sealed to a container 13 the cap 10 is positioned tightly on the neck of the container, the adhesive 44 seals the liner 40 to the cover 10 and the layer 42 seals the liner 40 to the container. As illustrated in Figure 8, when the cover is turned in a counterclockwise direction, the adhesive 44 tears the disc 41 due to the relative movement between the cover and disc. A similar rupture would occur if the cover were turned to a position matching an arrow on the cover with an arrow on the container to permit the cover to be lifted off the container. The removal of the cap thus also tears out the container seal affording direct immediate access to the contents without breaking another seal. This package could then be used for the sterile delivery of medical devices or materials in operating rooms, clinics etc. After the package is sealed, sterilization by ethylene oxide gas or gamma radiation can sterilize the contents, and they can be delivered sterile by removing the cap, thus tearing the seal, and emptying the container.

Figure 9 illustrates a further embodiment of the present invention wherein the cap 10 has a liner 40 sealed by adhesive 44 to the cap. A second liner 50 is placed in the cap in contact with the liner 40. Liner 50 may comprise a layer 51 of metal foil coated with a heat sealable material 52. When placed on a container the induction heating process causes the liner 40 to bond about its periphery to the layer 51 which in turn is bonded to the edge of the container surrounding the opening by layer 52. The layer 41 of liner 40 may be color coated or printed with suitable ink 22 to bear a desired message or the manufacturer's logo. The layer 51 of liner 50 may be printed with indicia of contrasting color or coated with a contrasting color to be clearly visible when the layer 41 is torn to indicate the cover has been tampered with or opened.

In Figure. 10 a cap 55 is illustrated which is of the child-resistant type which has a recess 56 formed on the side walls to mate over an interrupted rib 58 on the container 59. The cap 55 and container 59 each have an arrow 60 molded therein or placed thereon to permit the discontinuity in the rib 58 to be aligned with the projection 61 in the cap 55 to permit removal of the cap.

A deposit of adhesive 44 in the form of a spot of curable adhesive or a strip of pressure-sensitive adhesive extending across a surface of a disc 65 adheres the disc 65 to the cover. The disc 65 may be 0.0025 mm (0.001 inch) dead soft aluminum foil.

In this embodiment an activatable adhesive material 66 is coated on the container 59 on the surface surrounding the opening. This adhesive will bond the disc 65 to the container. One adhesive substance may be an ethylene vinyl acetate which will bond upon the application of heat. Other suitable adhesives may be coated on and activated by pressure.

Claims

1. A container having a cover member removably mounted over an opening in the container, an inner membrane sealed in fixed relationship to the container, characterized in that an adhesive (21, 44) bonds a portion of the membrane (20, 40) to the cover member (10, 55) leaving the remainder free of the cover member whereby relative movement between the cover member (10, 55) and the container (13, 59) will rupture the membrane.

2. A container and cover member according to claim 1 characterized in that said cover member is translucent and said adhesive comprises a deposit (21, 44) of adhesive within the cover member contacting securely said cover member and said inner membrane.

3. A container and cover member according to claim 1 characterized in that said membrane (16) is secured at its periphery to the inside of said cover member (10), said adhesive (21) contacts the surface of said membrane (16) opposite said cover and contacts a second membrane (20), which second membrane is fixed to said container (13).

4. A container and cover member according to claim 2 characterized in that said second membrane (20) has a visual appearance on the surface contacted by said deposit of adhesive different from said rupturable membrane (16).

5. A container and cover member according to claim 1 or 2 characterized in that said membrane is a metallic foil.

6. A container and cover member according to claim 2 or 5 characterized in that a printed message (46) appears on said rupturable membrane which is impaired upon relative movement of said cover member and said container.

7. A container and cover member according to claim 3 characterized in that said membrane (16) is adhered at its peripheral edge to the inside of said cover member, and said second membrane (20, 50) is disposed in said cover member having adhesive (29, 52) for adhering it to the container about said container opening, and wherein said adhesive (21, 42) is disposed between said membranes to secure the same together.

8. A container and cover member according to claim 3 characterized by the feature that said second membrane (20) has a visual appearance on the surface contacted by said adhesive (21) different from said membrane (16) which is rupturable more easily than the second membrane (20).

9. A container and cover member according to claim 8 characterized in that said rupturable membrane (16) is a metallic foil.