Note: Descriptions are shown in the official language in which they were submitted.
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RESEALABLE TAMPER-EVIDEN~ PACRAG~
The present invention relates to a resealable
tamper-evident package, useful for packaging a variety
of products including food products and medicines.
It is known from U.S. Patent No. 3,625,270 to
provide a resealable tamper-evident package formed of
flexible polymeric film. As described in that patent, a
resealable seal is provided by interlocking fastening
members provided in strip-like form molded to the
internal walls of the package while a tear ribbon is
provided for opening the package.
This prior art structure suffers from a number of
drawbacks, namely that the resealable seal requires
complex shapes to be molded to the wall of the bag and
the tear strip is provided as a separate element and is
required to extend beyond the edges of the package to
~acilitate opening of the package. The prior art
structure, therefore, is costly to manufacture and is
limited to moldable plastics.
In accordance with the present invention, there is
provided a considerably simplified resealable
tamper-evident package which does not suffer from the
prior art problems noted above. In the present
invention, a packaging structure of overlying layers of
flexible packaging material which is closed at each edge
thereof to define an enclosed interior cavity comprises
resealable seal means spaced from the top edge of the
packaging structure and extending substantially for the
width of the structure to permit the overlying layers to
be separated one from another and to be releasably
resealed one to another, and perforation means extending
through the overlying layers substantially for the width
of the structure in at least one line substantially
parallel to the resealable seal means and located
bet~een the top edge of the packaging structure and the
resealable seal means to permit the packaging structure
to be opened by the tearing off of a top strip of the
packaging structure along the perforation means.
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By providing a line of perforation extendi`ng for
the width of the package, the package may be maintained
in a permanently sealed condition until initial access
to the contents of the enclosure is required and
thereupon opening of the package is simply achieved by
tearing off the top strip of the package alony the line
of perforation. The line of perforation is readily
provided in the pacXage as a step of the form-and-fill
operation for the package and does not require a
complicated manufacturing procedure. Since a top strip
of the package is removed when torn along the line of
perforation, access to the contents of the package is
had directly through the top of the structure, which is
generally the most convenient to the consumer.
15By providing a resealable seal spaced ~rom the top
edge of the package a greater distance than the line of
perforation, once the top strip of the package has been
; removed along the line of perforation, initial access to
the contents of the enclosure may be had through the
resealable seal of the package and the package may
thereafter be reclosed by joining together of the
elements of the resealable seal.
A consumer purchasing a product in such a package
is able to determine very rapidly whethsr or not the
pacXage has been tampered with, prior to purchase of the
package. If the top strip is in place, the package
remains in its factory-sealed stal:e while, if the top
has been remoYed or the line of perforation has been
partially torn, the package has been tampered with and
product may have been removed from the package or
contaminated.
The material of construction of the packaging
structure is preferably flexible polymeric material,
most preferably in the form of non-laminated web, but
clearly the principles are also applicable to other
ij "flexible materials o~ construction, for example, paper
and metal foil.
The resealable seal preferably takes the form of a
resealable line seal comprising a line of adhesive
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mounted to one of the layers and extending for the width
of the package. The line of adhesive is releasably
bonded to the other layer to form the seal. This
structure is simple and effective, does not require
complicated interlocking elements that require molding
and does not restrict the polymeric materials of
construction of the package. The line of adhesive may
be provided or a strip of material which is laminated to
the polymeric material of the structure.
A wide variety of products may be packaged in the
packaging structure of the invention, including any
products conveniently and conventionally packaged by
form-and-fill techniques. The tamper-evident feature
is particularly useful when food products and medicines
are packaged, since it is important that such products
reach the consumer in their factory sealed condition to
avoid any possibility of product having been removed or
having become contaminated, either accidentally or
deliberately.
The invention is described further, by way of
illustration, with reference to the accompanying
j drawings, in which:
Figure 1 is an elevational view of a pacXaging
structure provided in accordance with one embodiment of
the invention; and
Figure 2 is a sche~atic representation of the heat
sealing jaws of a form-and-fill machine, modi~ied to
produce the packaging structure of Figure 1.
; Referring to Figure 1, there is shown therein a
packaging structure lO in accordance with one preferred
embodiment of the invention. The packaging structure 10
comprises overlying layers 12 and 14 o~ polymeric
material which are heat-sealed at their upper and lower
edges 16 and 18 respectively to define an enclosed
product-receiving cavity 20.
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In accordance with the invention, a pealable line
seal 22 i5 provided between the overlying layers 12 and
14 extending for the substantial width of the structure
; 10 parallel to and spaced from the top seal 16. The
pealable seal 22 comprises a line of adhesive provided
on the inner surface of one of two layers 12 and 14 and
releasably joined to the inner surfaces o the other of
the layers 12 and 14. The line of adhesive is
conveniently provided on a strip of polymeric material
which is laminated to the inner surface of one of the
two layers 12 and 14.
In addition, a line of per~oration 24 extends
across the width of the package between the top seal 16
and the pealable seal 22. The line of perforation 24
penetrates both layers 12 and 14 so as to permit the top
strip 26 between the top edge of the package 12 and the
line of perforation to be removed completely to achieve
initial opening of the package 10.
Once the top strip 26 has been removed selective
access to the contents of the cavity 20 may be achieved
by opening and closing the resealable seal 22. Access
, to the cavity 20 is attained through the top of the
structure.
The packaging structure 10 conveniently may be
formed by a modification of the conventional
form-and-fill technique. Referring now to Figure 2,
there are shown therein the heat-sealing jaws 50, 52 of
a form-and-fill machine. As is well known, in
conventional form-and-fill machines, a web of polymeric
material first is shaped to form a tubular shape, the
overlapping side edges of the web are sealed" the
tubular shape is sealed at the lower end by jaws 52~ the
items to be packaged then are dispensed into the
resulting tube through its open top, the upper end then
is sealed by jaws 50, the completed package is severed
from the web, and the cycle then is repeated to produce
multiple numbers of packages from the web.
In the present invention, the web 54 is provided
with adhesive strips 56 at locations required to provide
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the pealable seal 22 and a perforator or serrator 5~ is
mounted to the upper set of jaws 50 so as to form the
line of perforation 24 through the overlying layers
during heat sealing of the top seal 16 of the package
10. In addition, pressure-applying jaws also may be
provided to press the seal 22 together.
The web preferably is pre-printed on one side and
has a strip bearing the pealable seal 22 applied on the
other in registry with the printing. For these reasons,
it is preferred that the web be non-laminated, with
greater strengths being achieved by the use of thicker
webs.
The present invention, therefore, requires only
minimal structural modification to existing
form-and-fill machines to produce the packaging
structure from web modified to include the line seal 56.
No separate steps or operations are required to pxovide
the tear strip 26, in contrast to the prior art
discussed above.
In ~ummary of this disclosure, the present
invention provides a novel tamper-evident resealable
packaging structure which is simple, yet effective and
which does not require extensive processing operations
or expensive equipment to produce. Modifications ar~
possible within the scope of this invention.
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