NZ223908A - Security envelope - Google Patents

Description

'V" '■' v*- - 223B06 O © o PATKNTS FORM NO. S Fee No. 4: $200.00 After Provisional No: 223908 Dated: 16th March 1988 PATENTS ACT 1953 COMPLETE SPECIFICATION SECURITY ENVELOPE /V 17 APR1989 S, WE TRIGON PACKAGING SYSTEMS (NZ) LIMITED, a New Zealand company of Cnr Avalon Drive and Foreman Road, Hamilton, New Zealand. hereby declare the invention for which I/We pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: 1 This invention relates to security envelopes and more particularly to such envelopes that are designed to reveal attempts to open the same or to reveal that the same have been opened and resealed.

Security envelopes have been manufactured from plastic polymer films with special closure devices intended to reveal tampering. Sensitive information, whether stock securities, money or whatever, are commonly shipped by courier or special messenger in such envelopes. These envelopes are commonly sealed by a strip of hot melt adhesive that has been applied along with a release liner to one edge of the envelope opening during their manufacture. To seal such an envelope the release liner is pulled away and the envelope flap folded down into contact with the exposed strip of tacky adhesive. Because the adhesive remains tacky under normal environmental conditions, and because the polymer packaging film is quite flexible and easily distorted, it had been thought that any tampering would be easily self-evident. As an added precaution, special devices have been added, such as special printed designs applied to the closure portion of the envelope that would visually reveal stretching or distortion if the adhesive seal were tampered with. Other tamper-revealing devices have been employed also. The essential element, however, has been the use of a hot melt adhesive tape strip in combination with a flexible plastic polymer film envelope because of the ease with which such envelopes could be manufactured and because of the ease with which such envelopes could be firmly sealed It has come as quite a shock to the envelope manufacturers and their customers, therefore, to discover that clever thieves and tamperers have discovered relatively easy methods to open these hot melt adhesive sealed envelopes and reseal them without detection. A common technique is to freeze the sealed envelope adhesive strip, such as by applying dry ice or spraying with FREON (trade mark) from a spray can. By freezing the adhesive strip, the envelope closure flap can be carefully pried up away from the frozen adhesive; the adhesive in effect looses its grip on the smooth film of the envelope. Careful attention to this detail will leave the frozen adhesive strip intact. To reseal the envelope, the adhesive strip is merely warmed to room temperature, at which point it becomes tacky again, and the closure flap is simply reapplied to the adhesive strip. Other techniques have also been used that result in separation of the adhesive from the cover flap in an undetected way. This revelation resulted in the bottom dropping out of the market for such envelopes.

A primary object of the present invention is to provide a tamper evident envelope with a closure system that cannot be breached without the breach becoming apparent. A further object is to provide such a closure system that includes a mechanical, or structural, component that would reveal tampering, as opposed to printing applied to the envelope film. ; ^ These and other objects have been achieved in the present invention. During the manufacturing process, the opposed sides of the envelope are juxtaposed such that the edges that define the envelope opening are even with one another. A cover flap is secured to one side of the envelope at a location inward of the opening (i.e. toward the closed end) and is provided with sufficient width that it may be folded over the envelope opening and brought down against the opposite side of the envelope a sufficient distance to more than cover the opening. During the manufacturing process, a band of hot melt adhesive is applied to the inner surface of the cover flap at a location which will overlap the envelope opening when the cover flap is folded into sealing engagement with the envelope. The adhesive band is covered with a release strip which will be removed when the envelope is to be sealed. When the release tape is removed, and the cover flap applied in envelope-sealing engagement, the adhesive band will be so positioned that adhesive will be present on opposite sides of the envelope body, adjacent the opening, and across the envelope opening itself. In cross-section, the adhesive band, as applied to the envelope opening, will appear channel-shaped. Consequently, the adhesive will bond to itself, across the top of the envelope opening, as well as bond to the envelope body adjacent to the envelope opening. Consequently, the cover flap seal will comprise a channel-shaped band of adhesive sealing the opening in adhesive-to-adhesive contact and adhesive-to-film contact on both sides of the envelope opening. Any attempt to tamper with this closure system, such as by attempting to separate the cover flap film from the adhesive band or by separating the envelope body from the adhesive band, will not be disguiseable. While it might be possible to separate the film-adhesive bonding contact on either side of the envelope opening, it will not be possible to separate the adhesive-to-adhesive bonding contact across the opening itself without rupturing the adhesive band. Thus, any tampering will be self-evident by examining the closure.

Aspects of the present invention will now be described with reference to the accompanying drawings in which: Figure 1: is a side view of an envelope in accordance with one example of the present invention, and Figure 2: is a rear view of the envelope of Figure 1, and Figure 3: is a partial side view of the envelope of Figure 1 with the flap closed, and Figure 4: is a front view of the envelope of Figure 1 with the adhesive band, strips and release paper visible through the clear plastic flap, and '23908 Figure 5: is a partial perspective view of an envelope having a series of apertures in the front and rear panels adjacent the envelope opening.

With respect to the drawings an envelope generally indicated by arrow 1 comprises a front panel 2 and a rear panel 3 sealed about their side and bottom edges to form an open-topped configuration. An appendage generally indicated by arrow 4 is secured to the front panel 2 at a level below the opening and extends across the envelope.

The appendage 4 comprises a clear plastics strip having a band of adhesive 5 at the mid-region thereof which extends across and is adhered to the envelope front panel. A thin strip of hot melt adhesive 6 is provided below the band 5 and the appendage 4 can be provided with two further strips of hot melt adhesive 7. The appendage 4 is secured to the envelope during manufacture by the adhesive strip 6, and the adhesive band 5 and strips 7 are protected by a backing strip of release paper 8. The adhesive band 5 is approximately 25mm wide and the strips 6 and 7 approximately 1mm wide.

When the appendage 4 is fixed to the envelope front panel 2 a small portion of the adhesive band 5 underlies the uppermost edge 2a of the front panel 2 and a portion of the band 5 can be adhered to itself depending on the folded-down position of the appendage 4.

To use the envelope the operator inserts his material into the envelope, removes the release paper 8 to expose the adhesive band 5 and strips 7 and folds the appendage 4 over the opening and seals it to both the front and rear panels of the envelope.

The strips 7 may be arranged to coincide with a design 9 printed on the envelope rear cover and an alignment marking 10 guides the operator ensuring that the flap is correctly positioned at closure and to ensure a desired degree of adhesive to adhesive contact.

The security of the envelope may be enhanced by the provision of a series of aligned apertures 11 (see Figure 5) adjacent the opening positioned so that on removal of the release paper 8 and closure of the appendage the adhesive band 5 adheres to itself via the apertures 11.

Essentially, the envelope is secure by the adherence of the adhesive across the envelope opening. The band of adhesive 5, when the flap is closed, is doubled back onto itself across f & u o',s the envelope opening and adheres to itself as well as adhering to the side panels 2 and 3 adjacent the opening. To enter the envelope through its opening, the sealed adhesive channel 5 must be torn away from the opening, thus making a forced entry obvious through the distortion of tearing of the adhesive closure.

The adhesive may be situated on a clear flap at the opening of the envelope, the flap acting as a means of holding, registering and protecting the adhesive. If the adhesive closure is breached, as by attempting to freeze it and pry it away from the envelope opening, and then resealed, the broken or torn adhesive channel will be evident through the clear flap. A preferred adhesive is of the pressure-sensitive hot melt type which is applied to the flap at appropriate locations in liquid form at elevated temperatures. Suitable such adhesives include the ethylene copolymer based family of hot melt adhesives. If dry ice or Freon is applied to the adhesive, the adhesive would solidify and lose most of its strength. The flap can then easily be peeled off the envelope thus exposing the hot melt adhesive. However, envelope integrity is maintained as the band of adhesive is fused to itself across the top of the opening. In this frozen state the brittle adhesive can be easily shattered and the envelope entered, but such entry would be obvious from the appearance of the adhesive channel.

While the preferred embodiment of the invention has been described herein, variations in the design may be made. The scope of the invention therefore, is only to be limited by the claims appended hereto.

S'X; 223908 •rv

Claims (8)

WHAT WE CLAIM IS:

1. An envelope comprising a front and rear panel sealed about its side and bottom edges to form an open-topped configuration; an appendage secured to the front panel at a level below the envelope opening and extending across the front panel, said appendage having a length sufficient for a free end of the appendage to function as a closure flap that can be folded over the envelope and secured to the rear panel at a level below the envelope opening; and a band of adhesive adhered to and extending across said appendage at a mid-region thereof whereby, when said appendage is folded over and across said envelope opening in a closure relationship thereto, said adhesive band will contact both panels adjacent said opening.

2. The envelope of claim 1 wherein said appendage is provided with at least one additional strip of adhesive near an edge of the free end thereof to seal such free end against said rear panel when said appendage is folded in a closure relationship thereto.

3. The envelope of claim 1 or claim 2 wherein the adhesive in said band is provided in the form of a pressure-sensitive hot melt adhesive.

4. The envelope of any one of claims 1 to 3 wherein the panels of the envelope are provided with a plurality of aligned apertures adjacent the opening, the arrangement being such that when the appendage is folded over and across said envelope opening in a closure relationship the adhesive band will be joined via the apertures.

5. The envelope of any one of claims 1 to 4 wherein the rear panel of the envelope adjacent the opening is provided with a printed design thereon.

6. The envelope of any one of claims 1 to 5 wherein the appendage is manufactured from a clear material.

7. The envelope of any one of claims 1 to 6 wherein the rear panel is provided with an alignment marking which instructs the user to fold the appendage to affect closure thereof in such a manner that the adhesive band adheres to itself as well as the panels.

8. An envelope substantially as herein described with reference to the accompanying drawings. trigon packaging systems (nz) ltd by their Attorneys iambs^TweLls 6