CA1329176C - Tamper evident envelope closure system - Google Patents
Tamper evident envelope closure systemInfo
- Publication number
- CA1329176C CA1329176C CA 614774 CA614774A CA1329176C CA 1329176 C CA1329176 C CA 1329176C CA 614774 CA614774 CA 614774 CA 614774 A CA614774 A CA 614774A CA 1329176 C CA1329176 C CA 1329176C
- Authority
- CA
- Canada
- Prior art keywords
- envelope
- adhesive
- appendage
- opening
- band
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D27/00—Envelopes or like essentially-rectangular containers for postal or other purposes having no structural provision for thickness of contents
- B65D27/12—Closures
- B65D27/30—Closures with special means for indicating unauthorised opening
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D33/00—Details of, or accessories for, sacks or bags
- B65D33/16—End- or aperture-closing arrangements or devices
- B65D33/1691—End- or aperture-closing arrangements or devices using adhesive applied to attached closure elements
Abstract
ABSTRACT OF THE DISCLOSURE
A tamper-evident envelope with a closure system that cannot be breached (without the breach becoming apparent) is provided. A mechanical component is supplied, as opposed to mere printing applied to the envelope film. An adhesive band with a release tape strip, the use of hot-melt adhesive, and the configuration of the cover flap and other envelope components ensure that tampering will be immediately evident.
A tamper-evident envelope with a closure system that cannot be breached (without the breach becoming apparent) is provided. A mechanical component is supplied, as opposed to mere printing applied to the envelope film. An adhesive band with a release tape strip, the use of hot-melt adhesive, and the configuration of the cover flap and other envelope components ensure that tampering will be immediately evident.
Description
329~76 TAMPER EVIDENT ENVELOPE CLOSURE SYSTEM
FIELI~ OF THE INVENTION
This invention pertains to security envelopes and more ~ particularly to such envelopes that ara desi~ned to reveal ; 5 attempts to open the same and to reveal that the same have been opened and resealed.
BACKGROUND OF THE INVENTION
Security envelopes have been been manuFactured from plastic polymer ~ilms with special closure devices intended to reveal tamper~ng. Sensitive in~ormation, whether stock sacurities, money or whatever, are commonly shipped by courier or special messenger in such envelopes. Those envelopes are commo~ly sealcd by a strip of hot melt adhesive that has been applied along with a release liner to one edge o~ the envelope opening during their manufacture. To seal such an envelope, the release ltner ts pulled away and the envelope ~lap folded down 1nto contact with the exposed strip of tacky hot melt adhesive. Because the hot melt adhesive remains tacky under normal environmental conditions, and because the polymer packaging film is quits flextble and easily distorted, it had been thought that any tampering would be sasily self-evident. As an added precaution, special devices were added, such as special printed desi~ns applied to ths closure portion of the envelope that would visually reveal stretching or distortion if the adhesive seal were tampered with. Other tamper-revealing devlces have been employed also. The essential element, however, has been tha use of a hot melt adhesive tape strip in combinatlon with a flexible plastic polymer film envelope because of the ease with which suGh ~; envalopes cowld be manufactured and because of the ease with ~hich such envelopes could be firmly sealed.
~ It has come as quite a shock to the envelope manuf~cturers ;~ and their customers, therefore, to di~.cover that clever thieves and tamperers have discovered relative easy methods to opan these ~ hot melt adhesive sealed envelopes and reseal them wtthout ':
~'7 "
.' . .
' . ~ : ' .
~329176 `:
detectlon. A common technique ls to freeze the sealed envelope adheslve strlp, such as by applylng dry ice or spraying wlth Freon from a spray can. By freezing the adheslve strip, the envelope closure flap can be carefully prled up away from the frozen adhesive; the adheslve in effect looses lt~ grlp on the smooth ~, ~
~ fllm of the envelope. Careful attentlon to thls detall will leave ,, ; the frozen adheslve strlp lntact. To reseal the envelope the adheslve strlp ls merely warmed to room temperature, at whlch polnt lt becomes tacky agaln, and the closure flap is slmply reapplled to the adhesive strlp. Other technlques have also been used that result ln ~eparatlon of the adhesIve from the cover flap ~; ln an undetected way. Thls revelatlon resulted ln the bottom dropplng out of the market for such envelopes.
. ~, SUMMARY OF THE INVENTION
.
A prlmary ob~ect of the present lnventlon ls to provlde .
~:;
a tamper evldent envelope wlth a closure system that cannot be ~- breached without the breach becomlng apparent. A further ob~ect - ls to provlde such a closure system that lncludes a mechanlcal, or structural, component that would reveal tamperlng, as opposed to prlntlng applled to the envelope fll~.
The invention provldes an envelope comprlsing front and rear panels sealed about thelr slde and bottom edges to form an open-topped configuratlon; an appendage secured to one of sald panels at a level below the opening into the envelope opening and .;
extending across the panel, ~ald appendage having a wldth that is ~ubstantlally equal to the dlstance between the opposing side ., ~ edges of the envelope and having a length sufficient for the ,., "~
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, . , ;-, .
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` 132~176 2a appendage to functlon as a closure flap that can be folded over the envelope and æecured to the other of sald panels at a level below the envelope opening; and a band of adhesive adhered to and extendlng across sald appendage at a mld-reglon thereof whereby, when sald appendage ls folded over and across sald envelope openlng ln a closure relatlonship thereto, said adhesive band wlll contact both panels ad~acent said openlng and extend across said . . .
envelope openlng whereby the folding of sai.d appendage ln a closure relationshlp wlll result ln adheslve materlal adhered to ,.
both panels ad~acent the opening and adhered to ltself across the envelope opening as well as to ~ald appendage.
The lnventlon al80 provldes a process of manufacturlng a tamper evldent envelope comprlsing the steps of providlng a stock ,;.
of envelope panel materlal, provlding a stock of closure flap materlal, formlng the envelope panel materlal lnto ~uxtaposed ,~
envelope panels wlth a closed end bottom and an Gpen top, applylng a band of adheslve materlal lengthwlse along ~ald flap materlal, r,, ~ securing the flap materlal to one of sald panels ad~acent the open ,.'A,, top at a location whereby the adheslve band extends from one panel 1 20 outward and has a sufflclent width to be capable of belng folded ., .
acrogs the open top and secured to the opposlte panel, and severlng the comblned flap and envelope stock to provide dlscrete open top bags, whereln the severed closure flap has a length ,..
~`; substantlally equal to the width of the envelope.
..~.
Y~ Durlng the manufacturln~ process, the opposed sldes of ~ the envelope are ~uxtaposed ~uch that the edges that define the ......
~, envelope openlng are even wlth one another. A cover ~lap ls ~ .
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. ~: ; . .
. . .
:' ~ ~ ., . --` ~329176 2b secured to one slde of the envelope at a locatlon lnward of the openlng (l.e. toward the closed ~nd). During the manufacturlng process, a band of hot melt adheslve i5 applled to the lnner surface of the cover flap at a location whlch will overlap the envelope openlng when the cover flap is folded lnto seallng engagement with the envelope. The adhesive band is covered with a releare tape rtrlp whlch wlll be removed when the :, , .
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envslope ie to be sealed. When the release tape is removed, and the cover flap applied in envelope-seallng engagement, the adhesive band will be so positioned that adhesive will be pre~ent on opposite sides of the envelope body, adjacent the opening, and across the envelope opening itself. In cros~-section, tha ~ adhesive band, as applied to tha envelope opening, will appear - channal-shaped. Consequently, ths 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 atte~pt~ing to separate the cover flap film from the adhesive band or by separating the envelope body ~rom the adhesive band, will not be disguiseable. Wh1le it might be possible to separate the film-adhesive bonding contact on oither side of the envelope opening, it will not be possible to separate the adhasive-to-adhesive bonding contact across ths opening itself wtthout rupturing the adhesive band. Thus1 any tampering will be self-evidant by examining the closure.
RIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of an envelope in `~ accordance with one poss1ble embodimant of the present invention;
Figure ~ ts a diagrammatic view of the envelope flap in open position in accordance with one possible embodiment o~ the present invention; and ~` Figure 3 i~ a diagramAtic view of the envelope ~lap in closed position illustrating the channel-shaped con~uration of the sealed adhesivs band; and Figure 4 is a diagramat1c view of the envelope flap torn away from its closure position with the channël-~hapad adhesive band remaining in its sealed condition across the envelope openirl8-~,, ~ 35 DETAILED DESCRIPTION OF THE INVENTION
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' 1329~7t~
Attempts to tampor with security envelopes are becomingincreasingly sophisticated. The tools of a would be tamperer can include the use of dry ice, Freon from a spray can, a knife, a chem1cal such as a solvent or corrosive agent or heat. The disadvantayes with a number of security bags is that the above-mentioned methods can be used without giving evidence of tampering. Dry ice or Freon causes the adhesive to lose its adhesive strength, thus the envelope can be easily opened and the adhesive warmed to seal the envelope again, knives can cut the adhesive, again giving no evidence of tampering. Likewise the sof~ening o~ the adhasive through the use of solvents, corrosive agents or heat can be done in a manner such that the bag can be opaned and resealed after evaporat;on of the solvent or cooling of the adhesive.
It is an obJect of the present invention to provide a tamper-evident security envelope which addresses the above problems. Further objects and advantages will become apparent in the following description which is given by way of example.
According to ons aspect of the present invention there is provided an envelope comprising a front panel and a rear panel, an appendage in the form o~ a closur~ ~lap secured to one side of the envelope. The edges o~ the front and rear panels alcng one end, the upper end as depicted in Figure 1, are even with one another and define the opening into the envelope. A band of adhesive is applied to the envelope flap at a position such that the adhesive band will extend across the envelope oepning when the flap is placed in a closure position. The bag is preferably manufactured from any one of a number of plastics film, such as high density polyethylene and may be manufactured frem a laminate or co-extrusion having inner layers of plastics and an outer ~. layer of mica-filled or impregnated high density polyethylene.
`~ Essentially, the envelope is secured by the adherence of the adhesive across ths envelope opening. The band of adhesive, when the ~lap is closed9 is doubled back onto itself across the envelope opening and a~heres to itself as well as adhering to the ,, .
. .
. .
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.
, side panels adjacent the opening. To enter the envelope through its opening, the sealed adhasive channet must be tcrn away from the opentng, thus making a forced entry obvious through the distortion or tearing of the adhesive closure.
It is envisaged that the adhesive may bc si~uated on a clear flap at the opening of the envelope~ the flap acting as a means - of holding, regtstering and protecting the adhesive. If the adhesive closure ts breached, as by attempting to freeze it and pry it away from the envelope oepning, and then resealed, the broken or tern adhasive 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 locattons in liquid form at elevated temperatures and which becomes tacky, and hence self-adhesive, at room temperatures. Suitable such adhesives include the ethylene copolymer based famtly of hot melt adhesives. If dry ice or Freon is applied to the adhesive, the adhesive would solidify and lose most of tts strength. The flap can then easily be peeled off the envelope thus exposing the hot melt adhesive. However, envelope integrity is maintalned as the -~ 20 band of adhesiva is fused to itself across the top of the oepntng. In this frozen state tho britkle adhesive can ba easily shattered and the envelope entered, but such entry would be obvious from the appearance of the adhesive channel.
Attempts to enter the bag by cutting though the adhesive 25 would be difficult as it is envisaged that the adhesive may ``
extend to the edges of the panels thus giving nothing to grasp.
With reference to the drawings there is provided an envelope, generally indicatad by arrow 1 comprising a front panel ~-~` 2 and a rear panel 3. The envelope closure flap generally indicated by arrow 8 comprises clear polyethylane and may be attached to the bag via a 1mm strip of hot melt adhesive or heat sealed to the rear panel 3 as shown at 9, along the inner end of ~`~ the flap 8. Adhesive band 10, of hot melt adhesive, may be secured as shown tn Fi~ure 1 onto the flap ~ and axtend to the rl 35 edge ther~of. When the flap is attached as in Figure 1 the band .
..
.. . .. ...
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, ^ ~3291~6 is wide enough to extend from one panel, across the envelope opening to the other panel. The band 10 is approximately 30mm wide and consists of a contiguous layer of hot melt adhesive havin~ a thickness of about 1mm.
To protecit the hot melt pressure-sensitive band 10, a backing strip of release paper would be applied to cover the band during the manufacturing process. To use the envelope, the operator would insert the appropriate material into the envelope, remove the cover or backing strip to expose the adhasive band 10 on the flap 8, and fold the flap over the opening of the bag and seal the ~lap to both panels 2 a~d 3.
Because the band ie wide enou~h to extend across the openlng, sealing the envelope as described causes the adhesive from e~ich from separate locations on the single band to contact one another at the envelope opening. Consequently, the adhesive in the band adheres to both the adjacent panel 2 or 3 and to itself.
An additional strip or strips 11 of hot rnelt adhesive may be applied to the outer edge portion of flap 8 so that the free end of the flap may be secured to the snvelope front panel 2 when the flap is sealed to close the envalope. The additional adhesive strip or strips would be protected with a covering of release ;.j paper, also, which would be removed when the envelope was to be ~;' sealed. Actually, the same release paper strip usad to protect the adhesive closure band 10 could be extend to cover the strips 11 .
Any attempt to braach the bag's opening and then reseal the i bag will become apparent because the adhesive channel will have been torn and distorted. Even freaezing the hot melt adhesive of the band 10 will not prevent damage to the adhesiive strip. As an additional security feature, the closure flap 8 is perforated cross~wise at 12 near the outer edge of the adhesive band lO.
,i~, This perforated line 12 provides a mechainically-weakened line ~` that would rupture first if access to the envelope's contents were attempted by tearing or liflng the outer edge of the closure . ~
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1329~7~
strip 8 beyond that required to clear the outer sealing strips 11. The perforated line ~s pra~erably provlded as a series of short, narrow, longitudinal cuts through the closure strip material. During the manufacturing process, closure strip stock 5 would be perforated, as by running it acros~ a perforating whsel, to provide the perforated line 12. Providing the resultin~ cuts would not entail the removal of any material so that the adges of the material at the edges of the cuts would abut. Then the adhesive bands tO and 11 would be applied to the face of the 10 strip 8 in the locations shown. The band 10 would be applied to the closure strip 8 such that the outer edge of the band would extend beyond the perforated line 12. Consequently, if an attempt were made to gain access to a sealed envolope by lifting the free outer edge of the strip 8, the strip 8 would tear along 15 the weakened, perforated line 12, thereby evidencing the attempt to open. A strip of release paper would be applied to the face ; of the closure strip stock, leaving the envelope jo1nder adhesive strip 9 exposed. The closure strip stock would then be applied to envelope stock in a continuous process with the adhssive band 20 9 being rollsd onto the envelope stock to adher the closure strip b stock to the envelope stock. The combined stock then would be severed into discreke bags, or completed envelope~ each with its own discrete attached closure flap, to complete the manufacturing process. During the manufacturing process, sheet envelope stock ^~ 25 would be folded back on itsel~ to provide the envelopo panels 2 and 3, prior to the application of the closure strip stock.
Then, during the severance of the combined stock in~o discrete bags, or just prior thereto, tha ~ide edges of the overlapped envelope stock would be heat-sealed together to form the three-; 30 sided, open-topped bags illustrated in the Figures upon completion of the severing step.
- As a further measure, a s~milar perforated line could by provided near the inner edge of the band 10, so that the band ~ inner edge would axtend beyond this additional perforated line~
s 35 As in the case of the function of per~orated line 12, this ~`
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- additional parforated line, located underneath but near the inner edge of band 10, would be torn by the lifting of the inner edge of the closuro strip for the purpose of opening the envelope.
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 herato.
The embodimants of the invention in which an exclusive property is claimod are defined as follows:
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FIELI~ OF THE INVENTION
This invention pertains to security envelopes and more ~ particularly to such envelopes that ara desi~ned to reveal ; 5 attempts to open the same and to reveal that the same have been opened and resealed.
BACKGROUND OF THE INVENTION
Security envelopes have been been manuFactured from plastic polymer ~ilms with special closure devices intended to reveal tamper~ng. Sensitive in~ormation, whether stock sacurities, money or whatever, are commonly shipped by courier or special messenger in such envelopes. Those envelopes are commo~ly sealcd by a strip of hot melt adhesive that has been applied along with a release liner to one edge o~ the envelope opening during their manufacture. To seal such an envelope, the release ltner ts pulled away and the envelope ~lap folded down 1nto contact with the exposed strip of tacky hot melt adhesive. Because the hot melt adhesive remains tacky under normal environmental conditions, and because the polymer packaging film is quits flextble and easily distorted, it had been thought that any tampering would be sasily self-evident. As an added precaution, special devices were added, such as special printed desi~ns applied to ths closure portion of the envelope that would visually reveal stretching or distortion if the adhesive seal were tampered with. Other tamper-revealing devlces have been employed also. The essential element, however, has been tha use of a hot melt adhesive tape strip in combinatlon with a flexible plastic polymer film envelope because of the ease with which suGh ~; envalopes cowld be manufactured and because of the ease with ~hich such envelopes could be firmly sealed.
~ It has come as quite a shock to the envelope manuf~cturers ;~ and their customers, therefore, to di~.cover that clever thieves and tamperers have discovered relative easy methods to opan these ~ hot melt adhesive sealed envelopes and reseal them wtthout ':
~'7 "
.' . .
' . ~ : ' .
~329176 `:
detectlon. A common technique ls to freeze the sealed envelope adheslve strlp, such as by applylng dry ice or spraying wlth Freon from a spray can. By freezing the adheslve strip, the envelope closure flap can be carefully prled up away from the frozen adhesive; the adheslve in effect looses lt~ grlp on the smooth ~, ~
~ fllm of the envelope. Careful attentlon to thls detall will leave ,, ; the frozen adheslve strlp lntact. To reseal the envelope the adheslve strlp ls merely warmed to room temperature, at whlch polnt lt becomes tacky agaln, and the closure flap is slmply reapplled to the adhesive strlp. Other technlques have also been used that result ln ~eparatlon of the adhesIve from the cover flap ~; ln an undetected way. Thls revelatlon resulted ln the bottom dropplng out of the market for such envelopes.
. ~, SUMMARY OF THE INVENTION
.
A prlmary ob~ect of the present lnventlon ls to provlde .
~:;
a tamper evldent envelope wlth a closure system that cannot be ~- breached without the breach becomlng apparent. A further ob~ect - ls to provlde such a closure system that lncludes a mechanlcal, or structural, component that would reveal tamperlng, as opposed to prlntlng applled to the envelope fll~.
The invention provldes an envelope comprlsing front and rear panels sealed about thelr slde and bottom edges to form an open-topped configuratlon; an appendage secured to one of sald panels at a level below the opening into the envelope opening and .;
extending across the panel, ~ald appendage having a wldth that is ~ubstantlally equal to the dlstance between the opposing side ., ~ edges of the envelope and having a length sufficient for the ,., "~
" ,.
.~ ,. .. ..
, . , ;-, .
.. . .
: ' ;
` 132~176 2a appendage to functlon as a closure flap that can be folded over the envelope and æecured to the other of sald panels at a level below the envelope opening; and a band of adhesive adhered to and extendlng across sald appendage at a mld-reglon thereof whereby, when sald appendage ls folded over and across sald envelope openlng ln a closure relatlonship thereto, said adhesive band wlll contact both panels ad~acent said openlng and extend across said . . .
envelope openlng whereby the folding of sai.d appendage ln a closure relationshlp wlll result ln adheslve materlal adhered to ,.
both panels ad~acent the opening and adhered to ltself across the envelope opening as well as to ~ald appendage.
The lnventlon al80 provldes a process of manufacturlng a tamper evldent envelope comprlsing the steps of providlng a stock ,;.
of envelope panel materlal, provlding a stock of closure flap materlal, formlng the envelope panel materlal lnto ~uxtaposed ,~
envelope panels wlth a closed end bottom and an Gpen top, applylng a band of adheslve materlal lengthwlse along ~ald flap materlal, r,, ~ securing the flap materlal to one of sald panels ad~acent the open ,.'A,, top at a location whereby the adheslve band extends from one panel 1 20 outward and has a sufflclent width to be capable of belng folded ., .
acrogs the open top and secured to the opposlte panel, and severlng the comblned flap and envelope stock to provide dlscrete open top bags, whereln the severed closure flap has a length ,..
~`; substantlally equal to the width of the envelope.
..~.
Y~ Durlng the manufacturln~ process, the opposed sldes of ~ the envelope are ~uxtaposed ~uch that the edges that define the ......
~, envelope openlng are even wlth one another. A cover ~lap ls ~ .
' ''', ' ' ~ '~ ' ~ `
. ~: ; . .
. . .
:' ~ ~ ., . --` ~329176 2b secured to one slde of the envelope at a locatlon lnward of the openlng (l.e. toward the closed ~nd). During the manufacturlng process, a band of hot melt adheslve i5 applled to the lnner surface of the cover flap at a location whlch will overlap the envelope openlng when the cover flap is folded lnto seallng engagement with the envelope. The adhesive band is covered with a releare tape rtrlp whlch wlll be removed when the :, , .
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, . . .
, ~
.~ . .
.. . .
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`` ~ 32917~
envslope ie to be sealed. When the release tape is removed, and the cover flap applied in envelope-seallng engagement, the adhesive band will be so positioned that adhesive will be pre~ent on opposite sides of the envelope body, adjacent the opening, and across the envelope opening itself. In cros~-section, tha ~ adhesive band, as applied to tha envelope opening, will appear - channal-shaped. Consequently, ths 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 atte~pt~ing to separate the cover flap film from the adhesive band or by separating the envelope body ~rom the adhesive band, will not be disguiseable. Wh1le it might be possible to separate the film-adhesive bonding contact on oither side of the envelope opening, it will not be possible to separate the adhasive-to-adhesive bonding contact across ths opening itself wtthout rupturing the adhesive band. Thus1 any tampering will be self-evidant by examining the closure.
RIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of an envelope in `~ accordance with one poss1ble embodimant of the present invention;
Figure ~ ts a diagrammatic view of the envelope flap in open position in accordance with one possible embodiment o~ the present invention; and ~` Figure 3 i~ a diagramAtic view of the envelope ~lap in closed position illustrating the channel-shaped con~uration of the sealed adhesivs band; and Figure 4 is a diagramat1c view of the envelope flap torn away from its closure position with the channël-~hapad adhesive band remaining in its sealed condition across the envelope openirl8-~,, ~ 35 DETAILED DESCRIPTION OF THE INVENTION
,;, ,, . .
... .
' 1329~7t~
Attempts to tampor with security envelopes are becomingincreasingly sophisticated. The tools of a would be tamperer can include the use of dry ice, Freon from a spray can, a knife, a chem1cal such as a solvent or corrosive agent or heat. The disadvantayes with a number of security bags is that the above-mentioned methods can be used without giving evidence of tampering. Dry ice or Freon causes the adhesive to lose its adhesive strength, thus the envelope can be easily opened and the adhesive warmed to seal the envelope again, knives can cut the adhesive, again giving no evidence of tampering. Likewise the sof~ening o~ the adhasive through the use of solvents, corrosive agents or heat can be done in a manner such that the bag can be opaned and resealed after evaporat;on of the solvent or cooling of the adhesive.
It is an obJect of the present invention to provide a tamper-evident security envelope which addresses the above problems. Further objects and advantages will become apparent in the following description which is given by way of example.
According to ons aspect of the present invention there is provided an envelope comprising a front panel and a rear panel, an appendage in the form o~ a closur~ ~lap secured to one side of the envelope. The edges o~ the front and rear panels alcng one end, the upper end as depicted in Figure 1, are even with one another and define the opening into the envelope. A band of adhesive is applied to the envelope flap at a position such that the adhesive band will extend across the envelope oepning when the flap is placed in a closure position. The bag is preferably manufactured from any one of a number of plastics film, such as high density polyethylene and may be manufactured frem a laminate or co-extrusion having inner layers of plastics and an outer ~. layer of mica-filled or impregnated high density polyethylene.
`~ Essentially, the envelope is secured by the adherence of the adhesive across ths envelope opening. The band of adhesive, when the ~lap is closed9 is doubled back onto itself across the envelope opening and a~heres to itself as well as adhering to the ,, .
. .
. .
:`
':
; ~ , .~, .
.
, side panels adjacent the opening. To enter the envelope through its opening, the sealed adhasive channet must be tcrn away from the opentng, thus making a forced entry obvious through the distortion or tearing of the adhesive closure.
It is envisaged that the adhesive may bc si~uated on a clear flap at the opening of the envelope~ the flap acting as a means - of holding, regtstering and protecting the adhesive. If the adhesive closure ts breached, as by attempting to freeze it and pry it away from the envelope oepning, and then resealed, the broken or tern adhasive 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 locattons in liquid form at elevated temperatures and which becomes tacky, and hence self-adhesive, at room temperatures. Suitable such adhesives include the ethylene copolymer based famtly of hot melt adhesives. If dry ice or Freon is applied to the adhesive, the adhesive would solidify and lose most of tts strength. The flap can then easily be peeled off the envelope thus exposing the hot melt adhesive. However, envelope integrity is maintalned as the -~ 20 band of adhesiva is fused to itself across the top of the oepntng. In this frozen state tho britkle adhesive can ba easily shattered and the envelope entered, but such entry would be obvious from the appearance of the adhesive channel.
Attempts to enter the bag by cutting though the adhesive 25 would be difficult as it is envisaged that the adhesive may ``
extend to the edges of the panels thus giving nothing to grasp.
With reference to the drawings there is provided an envelope, generally indicatad by arrow 1 comprising a front panel ~-~` 2 and a rear panel 3. The envelope closure flap generally indicated by arrow 8 comprises clear polyethylane and may be attached to the bag via a 1mm strip of hot melt adhesive or heat sealed to the rear panel 3 as shown at 9, along the inner end of ~`~ the flap 8. Adhesive band 10, of hot melt adhesive, may be secured as shown tn Fi~ure 1 onto the flap ~ and axtend to the rl 35 edge ther~of. When the flap is attached as in Figure 1 the band .
..
.. . .. ...
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, ^ ~3291~6 is wide enough to extend from one panel, across the envelope opening to the other panel. The band 10 is approximately 30mm wide and consists of a contiguous layer of hot melt adhesive havin~ a thickness of about 1mm.
To protecit the hot melt pressure-sensitive band 10, a backing strip of release paper would be applied to cover the band during the manufacturing process. To use the envelope, the operator would insert the appropriate material into the envelope, remove the cover or backing strip to expose the adhasive band 10 on the flap 8, and fold the flap over the opening of the bag and seal the ~lap to both panels 2 a~d 3.
Because the band ie wide enou~h to extend across the openlng, sealing the envelope as described causes the adhesive from e~ich from separate locations on the single band to contact one another at the envelope opening. Consequently, the adhesive in the band adheres to both the adjacent panel 2 or 3 and to itself.
An additional strip or strips 11 of hot rnelt adhesive may be applied to the outer edge portion of flap 8 so that the free end of the flap may be secured to the snvelope front panel 2 when the flap is sealed to close the envalope. The additional adhesive strip or strips would be protected with a covering of release ;.j paper, also, which would be removed when the envelope was to be ~;' sealed. Actually, the same release paper strip usad to protect the adhesive closure band 10 could be extend to cover the strips 11 .
Any attempt to braach the bag's opening and then reseal the i bag will become apparent because the adhesive channel will have been torn and distorted. Even freaezing the hot melt adhesive of the band 10 will not prevent damage to the adhesiive strip. As an additional security feature, the closure flap 8 is perforated cross~wise at 12 near the outer edge of the adhesive band lO.
,i~, This perforated line 12 provides a mechainically-weakened line ~` that would rupture first if access to the envelope's contents were attempted by tearing or liflng the outer edge of the closure . ~
., .
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". , , . ~ . . ..
.,, ~ :,, , ~ ~'' '' ' '': -,'`,''~ . .
1329~7~
strip 8 beyond that required to clear the outer sealing strips 11. The perforated line ~s pra~erably provlded as a series of short, narrow, longitudinal cuts through the closure strip material. During the manufacturing process, closure strip stock 5 would be perforated, as by running it acros~ a perforating whsel, to provide the perforated line 12. Providing the resultin~ cuts would not entail the removal of any material so that the adges of the material at the edges of the cuts would abut. Then the adhesive bands tO and 11 would be applied to the face of the 10 strip 8 in the locations shown. The band 10 would be applied to the closure strip 8 such that the outer edge of the band would extend beyond the perforated line 12. Consequently, if an attempt were made to gain access to a sealed envolope by lifting the free outer edge of the strip 8, the strip 8 would tear along 15 the weakened, perforated line 12, thereby evidencing the attempt to open. A strip of release paper would be applied to the face ; of the closure strip stock, leaving the envelope jo1nder adhesive strip 9 exposed. The closure strip stock would then be applied to envelope stock in a continuous process with the adhssive band 20 9 being rollsd onto the envelope stock to adher the closure strip b stock to the envelope stock. The combined stock then would be severed into discreke bags, or completed envelope~ each with its own discrete attached closure flap, to complete the manufacturing process. During the manufacturing process, sheet envelope stock ^~ 25 would be folded back on itsel~ to provide the envelopo panels 2 and 3, prior to the application of the closure strip stock.
Then, during the severance of the combined stock in~o discrete bags, or just prior thereto, tha ~ide edges of the overlapped envelope stock would be heat-sealed together to form the three-; 30 sided, open-topped bags illustrated in the Figures upon completion of the severing step.
- As a further measure, a s~milar perforated line could by provided near the inner edge of the band 10, so that the band ~ inner edge would axtend beyond this additional perforated line~
s 35 As in the case of the function of per~orated line 12, this ~`
.
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,~ , .... .
:
- , 132~17~
- additional parforated line, located underneath but near the inner edge of band 10, would be torn by the lifting of the inner edge of the closuro strip for the purpose of opening the envelope.
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 herato.
The embodimants of the invention in which an exclusive property is claimod are defined as follows:
:'.
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~: 30 ~, ,,.,~, ., , .. 35 i:
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,
Claims (8)
1. An envelope comprising front and rear panels sealed about their side and bottom edges to form an open-topped configuration, an appendage secured to one of said panels at a level below the opening into the envelope opening and extending across the panel, said appendage having a width that is substantially equal to the distance between the opposing side edges of the envelope and having a length sufficient for the appendage to function as a closure flap that can be folded over the envelope and secured to the other of said panels 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 and extend across said envelope opening whereby the folding of said appendage in a closure relationship will result in adhesive material adhered to both panels adjacent the opening and adhered to itself across the envelope opening as well as to said appendage.
2. The envelope of claim 1, wherein said appendage is provided with at least one additional strip of adhesive near the free end thereof to seal such free end against said front panel when said appendage is folded in a closure relationship thereto.
3. The envelope of claim 1, wherein the adhesive in said band is provided in the form of a pressure-sensitive hot melt adhesive.
4. An envelope comprising front and rear panels formed of plastic film sealed about their side and bottom edges to form an open-topped configuration; an appendage formed of a plastic film secured to one of said panels at a level below the opening into the envelope opening and extending across the panel, said appendage having a width that is substantially equal to the distance between the opposing side edges of the envelope and having a length sufficient for the appendage to function as a closure flap that can be folded over the envelope and secured to the other of said panels at a level below the envelope opening;
and a band of pressure-sensitive hot melt 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 and extend across said envelope opening whereby the folding of said appendage in a closure relationship will result in adhesive material adhered to both panels adjacent the opening and adhered to itself across the envelope opening as well as to said appendage.
and a band of pressure-sensitive hot melt 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 and extend across said envelope opening whereby the folding of said appendage in a closure relationship will result in adhesive material adhered to both panels adjacent the opening and adhered to itself across the envelope opening as well as to said appendage.
5. The envelope of claim 4, wherein said appendage is provided with at least one additional strip of adhesive near the free end thereof to seal such free end against said front panel when said appendage is folded in a closure relationship thereto.
6. The envelope of claim 4, wherein said appendage is provided with a line of perforations extending from one edge of the envelope to an opposite edge of the envelope underneath the band of adhesive, said line of perforations being located near the outer edge of said adhesive band.
7. A process of manufacturing a tamper evident envelope comprising the steps of providing a stock of envelope panel material, providing a stock of closure flap material, forming the envelope panel material into juxtaposed envelope panels with a closed end bottom and an open top, applying a band of adhesive material lengthwise along said flap material, securing the flap material to one of said panel, adjacent the open top at a location whereby the adhesive band extends from one panel outward and has a sufficient width to be capable of being folded across the open top and secured to the opposite panel, and severing the combined flap and envelope stock to provide discrete open top bags, wherein the severed closure flap has a length substantially equal to the width of the envelope.
8. The process of claim 7, including the step of perforating said strip stock prior to applying the adhesive band thereto whereby a perforated longitudinal line is applied to said strip stock and then covered by said adhesive band, said perforated line being located underneath but adjacent the outer edge of said adhesive band.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US33970489A | 1989-04-18 | 1989-04-18 | |
| US339,704 | 1989-04-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1329176C true CA1329176C (en) | 1994-05-03 |
Family
ID=23330237
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 614774 Expired - Fee Related CA1329176C (en) | 1989-04-18 | 1989-09-29 | Tamper evident envelope closure system |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0393841B1 (en) |
| CA (1) | CA1329176C (en) |
| DE (1) | DE69002788D1 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2247857A (en) * | 1990-08-01 | 1992-03-18 | Trigon Packaging Systems | Plastics film with permanent fold |
| US5205649A (en) * | 1990-08-29 | 1993-04-27 | Trigon Packaging Corporation | Leakproof packaging |
| US5360270A (en) * | 1992-04-28 | 1994-11-01 | Minnesota Mining And Manufacturing Company | Reusable security enclosure |
| US5318364A (en) * | 1992-10-28 | 1994-06-07 | Raden David T | Security bag |
| EP0633194B1 (en) * | 1993-07-09 | 1996-12-04 | C. Vaucher Unternehmensberatung | Mailing envelope |
| DE29511385U1 (en) * | 1995-07-14 | 1995-10-12 | Stausberg Gregor | Data-safe letter mail |
| US5918983A (en) * | 1996-11-08 | 1999-07-06 | Control Paper Co., Inc. | Security envelope |
| US5931581A (en) * | 1997-05-19 | 1999-08-03 | Dennis Garberg & Associates, Inc. | Self-sealable packaging for enclosing articles |
| FR2867754B1 (en) * | 2004-03-18 | 2006-06-23 | Plastijo | BAG-SHAPED PACKAGING |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2181252A (en) * | 1933-10-10 | 1939-11-28 | Vogel Max | Safety envelope |
| DE1486340A1 (en) * | 1962-11-13 | 1969-04-17 | Feldmuehle Ag | A bag filled with articles equipped with a combination of adhesive tape closure and a once-used closure |
| GB1536784A (en) * | 1977-05-04 | 1978-12-20 | Jennings Ab | Security bags |
| AU523051B2 (en) * | 1978-12-15 | 1982-07-08 | Arvey Corporation | Contaminant proof seal |
| US4483018A (en) * | 1981-02-09 | 1984-11-13 | Impakt Products, Inc. | High integrity tamper resistant container |
| GB8620636D0 (en) * | 1986-08-26 | 1986-10-01 | Mardon Wrappings Ltd | Containers |
-
1989
- 1989-09-29 CA CA 614774 patent/CA1329176C/en not_active Expired - Fee Related
-
1990
- 1990-03-16 DE DE9090302862T patent/DE69002788D1/en not_active Expired - Lifetime
- 1990-03-16 EP EP19900302862 patent/EP0393841B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0393841A1 (en) | 1990-10-24 |
| EP0393841B1 (en) | 1993-08-18 |
| DE69002788D1 (en) | 1993-09-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |