U.S. patent application number 10/461302 was filed with the patent office on 2004-02-26 for method for forming reclosable access portals in film packaging.
Invention is credited to Ebbers, Ton A.J.L., van Raaij, Peter J.J..
Application Number | 20040035719 10/461302 |
Document ID | / |
Family ID | 29736497 |
Filed Date | 2004-02-26 |
United States Patent
Application |
20040035719 |
Kind Code |
A1 |
Ebbers, Ton A.J.L. ; et
al. |
February 26, 2004 |
Method for forming reclosable access portals in film packaging
Abstract
The present invention is directed to means for forming
frangible, reclosable access portals in various types of film
packaging, and specifically, to means for forming reclosable access
portals that exhibit improved uniformity in the presentation of the
access port beneficial for forming an effective reclosable seal,
while substantially reducing the potential of deleterious tearing
of the film packaging. The access port is formed from a region of
the film packaging, which has been subjected to mechanical
weakening of the film substrate, wherein the weakened regions
include frangible, failure elements and force directing elements.
Failure elements of the weakened region induce the film substrate
to preferentially fail (i.e. tear) continuously in the general
direction and bounds of the element.
Inventors: |
Ebbers, Ton A.J.L.;
(Ven-Zelderheide, NL) ; van Raaij, Peter J.J.;
(Millingen a/d Rijn, NL) |
Correspondence
Address: |
WOOD, PHILLIPS, KATZ, CLARK & MORTIMER
500 W. MADISON STREET
SUITE 3800
CHICAGO
IL
60661
US
|
Family ID: |
29736497 |
Appl. No.: |
10/461302 |
Filed: |
June 13, 2003 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60388576 |
Jun 13, 2002 |
|
|
|
Current U.S.
Class: |
206/1.5 ;
206/497 |
Current CPC
Class: |
B65D 75/58 20130101;
B65D 75/5833 20130101; B65B 61/18 20130101 |
Class at
Publication: |
206/1.5 ;
206/497 |
International
Class: |
A45C 013/10; A45C
013/18 |
Claims
What is claimed is:
1. A method for forming access portals in film packaging,
comprising the steps of: a. providing a film substrate, b.
providing a means for imparting a weakened region in the film
substrate, wherein said weakened region includes at least one
failure element and at least one force directing element, and c.
inducing said weakened region into said film substrate wherein said
force directing element deviate from the failure element by an
incident angle of at least 10 degrees as defined by the failure
element.
2. A method for forming access portals as in claim 1, wherein said
film substrate is of heterogeneous formation.
3. A method for forming access portals as in claim 1, wherein said
means for imparting a weakened region are selected from the group
consisting of mechanical knives, laser ablation, roll embossing,
hydraulic energy, and the combinations thereof.
4. A method for forming access portals in film packaging as in
claim 1, wherein said failure elements are formed from full-depth
perforations.
5. A film package for products comprising of a film substrate,
wherein said film substrate comprises at least one access portal,
said access portal formed in the surface of the film substrate so
as to create a weakened region, said weakened region including at
least one failure element and at least one force directing element,
wherein said force directing element deviates from the failure
element by an incident angle of at least 10 degrees as defined by
the failure element.
Description
TECHNICAL FIELD
[0001] The present invention is directed to means for forming
frangible, reclosable access portals in various types of film
packaging, and specifically, to means for forming reclosable access
portals that exhibit improved uniformity in the presentation of the
access port beneficial for forming an effective reclosable seal,
while substantially reducing the potential of deleterious tearing
of the film package.
BACKGROUND OF THE INVENTION
[0002] The use of film packaging is well known in the art as a
means for sealing a product within a controlled environment and to
prevent detrimental contamination. Products that have benefitted
from such packaging include food products, tobacco, photographic
film, medical aids, personal hygiene materials and home care
agents. Of particular note, those products that are pre-moistened
require an effective combination of durable film packaging with a
strong, hermetic seal. The seal is not only a protective measure,
but also, the unbroken seal indicates to the consumer that the
package has not been improperly handled.
[0003] Typical retail availability of products ensconced in durable
film packaging includes having packages that contain more than one
such product, or plural elements, such as sheets, of the same
product. In situations where the product is adversely affected by
continued exposure to the environment, it is necessary in such
plural element packaging that a seal can be reformed in the
packaging after the initial element is removed, and that such seal
be sufficiently effective to maintain the quality of the remaining
elements until the last element is removed and the now empty
packaging discarded.
[0004] A retail film package must be able to resist mechanical
failure and contamination during shipping and handling, and yet be
accessible to the common user. Forming frangible access portals in
film packaging that are receptive to reclosable actions are complex
due to the necessary combination of a durable film package and a
strong, hermetic seal. Various prior art attempts have been made to
form suitable closure means that do not compromise the ability of
the film package to perform, including the use of molded
thermoplastic closures and replaceable adhesive tabs. Molded
thermoplastic closures allow for positive sealing action, but
require additional forming steps. Further such thermoplastic
closures require affixing to the film packaging, wherein such
joining is in itself durable and leak-proof, and can form alternate
paths of contamination including introduction of adhesives into the
sealed environment within the film package.
[0005] Replaceable adhesive tabs require the formation of an access
way into the interior of the sealed film package. Typical practices
for forming such access ways include perforating or otherwise
pre-cutting and preferentially weakening regions in the film face.
The frangible pre-cut region is then forced open by the consumer by
tearing of the film face, a process which has been found to be a
very difficult to perform not only completely, but also in such a
way as to prevent over-extension or miss-direction of the tearing
force that results in a subsequent failure of the reclosable
mechanism. Such over-extension failures are particularly evident
when oriented films are used as one or more layers in the film
substrate, with tearing tending to propagate in the direction of
film orientation.
[0006] An unmet need exists for a method of forming reclosable
access portals in film packaging that maintains the sealed
environment during shipping and handling, and yet can be readily
utilized by the common consumer, and which substantially reduces
the potential of deleterious tearing or over-extension of the
access way.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to means for forming
frangible, reclosable access portals in various types of film
packaging, and specifically, to means for forming reclosable access
portals that exhibit improved uniformity in the presentation of the
access port beneficial for forming an effective reclosable seal,
while substantially reducing the potential of deleterious tearing
of the film packaging. The access port is formed from a region of
the film packaging, which has been subjected to mechanical
weakening of the film substrate, wherein the weakened regions
include frangible, failure elements and force directing elements.
Failure elements of the weakened region induce the film substrate
to preferentially fail (i.e. tear) continuously in the general
direction and bounds of the element. Representative failure
elements include complete depth perforations, partial depth
perforations, scoring, and embossed or otherwise thinned film
substrate areas. Force directing elements are discontinuities in
the failure element that redirect the force vector in a direction
of at least 10 degrees from the continuous path, generally defined
by the failure elements. By combining failure elements and force
directing elements in the region of the access port, the film can
be induced to fail in a controlled and reproducible way, thus
allowing for improved re-closure performance.
[0008] The film packaging may comprise any suitable homogenous or
heterogeneous substrate, optionally of either laminate or composite
construction, which is compatible with the intended product to be
so contained. The film substrate may include barrier performance
agents such as fatty acids, as well as topically applied aesthetic
modifiers such as colorants and printed inks.
[0009] It is presently envisioned that any profile of access
portals can be practiced in accordance with the present invention,
including, but not limited to; slits, ellipses, rectangles, and the
combinations thereof, in which there is a combination of failure
elements and force directors are combined in a discontinuous
failure zone.
[0010] By application of the present invention, film packaging can
be produced which forms uniform and reproducible access portals. It
is within the purview of the invention that food materials, as well
as hygienic, medical and home care products, can be packaged in
suitable film substrates, wherein the clearly formed access portal
allows for effective reclosable access.
DETAILED DESCRIPTION OF THE FIGURES
[0011] FIG. 1 is a photograph of a typical retail product as packed
in a film package with a conventional unopened access port;
[0012] FIG. 2 is a photograph of an oval knife as is conventionally
practiced in the formation of prior art access portals in retail
film packaging;
[0013] FIG. 3 is a photograph of a retail film package wherein the
access port has been formed utilizing the oval knife of FIG. 2;
[0014] FIG. 4 is a photograph of a modified knife having failure
elements and force directing elements in accordance with the
present invention; and
[0015] FIG. 5 is a photograph of a retail film package wherein the
access port has been formed by way of the interaction of the
failure elements and force directing elements.
DETAILED DESCRIPTION
[0016] While the present invention is susceptible of embodiment in
various forms, there will hereinafter be described, presently
preferred embodiments, with the understanding that the present
disclosure is to be considered as an exemplification of the
invention, and is not intended to limit the invention to the
specific embodiments disclosed herein.
[0017] The present invention is directed to a means for forming
frangible access portals in weakened regions of film packaging,
which entails the combination of failure elements and force
directing elements. Failure elements of the weakened region induce
the film substrate to preferentially fail (i.e. tear) continuously
in the general direction and bounds of the element. Representative
failure elements include complete depth perforations, partial depth
perforations, suitable scoring, and embossed or otherwise thinned
film substrate areas. Force directing elements are discontinuities
in the failure element that redirect the force vector in a
direction of at least 10 degrees from the continuous path.
[0018] The failure elements enable the film to be torn by inducing
a localized weakness in the film substrate. As force is applied to
the failure elements, a tear is initiated in the film substrate, a
tear which then propagates in the general direction and orientation
of the failure element through continued application of force. At
selected points along the failure element, wherein the incident
angle of the failure element deviates by at least 10 degrees, force
directing elements are introduced. Force directing elements
terminate the propagation of the failure in the film substrate and
allow for the force vector to be redirected from the continuous
path. Such restraint of the tear prevents over-extension of the
access portal beyond a predefined area in the face of the film
packaging. Further, the force vector can be reoriented so as to
initiate a new failure in the film substrate that is in a direction
at least 10 degrees off of the path of the previous failure
element. Such re-direction failure in the film substrate for
forming an access opening therein can e particularly desirable in
the case of oriented film substrates, where it can be desirable to
form an opening which extends at least partially traversely to the
direction of film orientation.
[0019] Suitable means for introducing failure elements and force
directing elements into film substrates for packaging include the
application of mechanical disruption of the film substrate, such as
by application of metal knives, laser ablation, roll embossing, and
hydraulic energy. The most preferred mechanism for inducing a
frangible weakened region is through the use of metal knives that
are forced against the film substrate. When metal knives are used,
such as when presented as a cutting surface asperity in a section
of tool steel, on a film substrate, the pressure and temperature of
the process can be modulated simultaneously to obtain optimum
cutting performance.
EXAMPLES
[0020] FIG. 1 depicts a representative product, which has been
ensconced within film packaging. This particular product does not
include any access portals as a way to obtain material from within
the confines of the packaging. FIG. 2 is a sample of a cutting
knife as has been practiced in the prior art, represented by U.S.
Pat. No. 5,379,897, incorporated herein by reference. The
knife-edge is presented as an elliptical surface asperity
projecting out of the face of the tool steel base, which in turn,
defines a failure element that extends continuously about the
weakened region. When the prior art cutting knife is used to form a
weakened region in the surface of the representative product, and
force is subsequently applied to the region so as to form an access
way, tears propagate beyond the boundaries defined by the cutting
knife, as shown in FIG. 3.
[0021] FIG. 4 provides a representative cutting knife embodying the
teachings of the present invention. The elliptical failure element
includes two force directing elements, 2 and 3. The force directing
elements are at least 10 degrees off of the incident angle defined
by the failure element; in the illustrated embodiment, the force
direct elements are oriented at approximately 90 degrees to the
direction of tearing defined by the otherwise elliptical failure
element. When the cutting knife of FIG. 4 is used to form a
weakened region in the surface of the representative product, and
force is applied, the tears propagate in the region specifically
defined by the conjoined failure elements and force directing
elements, and do not extend beyond the boundaries. Element 1
illustrated in FIG. 4 facilitates complete formation of the access
opening, and forms a connector joining the separated portion to the
remainder of the substrate.
[0022] From the foregoing, numerous modifications and variations
can be effected without departing from the true spirit and scope of
the novel concept of the present invention. It is to be understood
that no limitation with respect to the specific embodiments
disclosed herein is intended or should be inferred. The disclosure
is intended to cover, by the appended claims, all such
modifications as fall within the scope of the claims.
* * * * *