U.S. patent number 3,593,483 [Application Number 04/845,201] was granted by the patent office on 1971-07-20 for method of forming a package with easy opening device.
This patent grant is currently assigned to The Kartridg Pak. Co.. Invention is credited to Alan C. Tracy.
United States Patent |
3,593,483 |
Tracy |
July 20, 1971 |
METHOD OF FORMING A PACKAGE WITH EASY OPENING DEVICE
Abstract
A package and a method of forming the same wherein a plastic
film is formed into a tube and filled with a flowable product,
margins of the film being overlapped and sealed with a tear strip
in the seam thus formed which is fabricated of a material having a
tear strength greater than the film, which has a width sufficient
to extend along both sides of the seal line and a length sufficient
to extend the full length of the package so that the ends thereof
are anchored in the ends of the package which are gathered and
sealed with bendable clips of metal or similar material. A pair of
longitudinally spaced transverse slits are cut in the outside edge
of the tear strip and the film margin to facilitate tearing either
circumferentially or longitudinally so as to open the package.
Inventors: |
Tracy; Alan C. (Davenport,
IA) |
Assignee: |
The Kartridg Pak. Co.
(Davenport, IA)
|
Family
ID: |
25294634 |
Appl.
No.: |
04/845,201 |
Filed: |
July 28, 1969 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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730411 |
May 20, 1968 |
3497131 |
Feb 24, 1970 |
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Current U.S.
Class: |
53/412; 53/451;
53/551 |
Current CPC
Class: |
B65B
61/182 (20130101); A22C 2013/0036 (20130101) |
Current International
Class: |
B65B
61/18 (20060101); B65b 061/18 () |
Field of
Search: |
;53/14,133,137,180
;93/1TS,82 ;99/171 ;229/51C,51S,51AS,66 ;156/203,466 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Condon; Theron E.
Assistant Examiner: Abrams; Neil
Parent Case Text
This application is a division of my application Ser. No. 730,411,
filed May 20, 1968 now Pat. No. 3,497,131 dated Feb. 24, 1970.
Claims
I claim:
1. A method of fabricating a package which comprises forming a tube
of relatively thin, plastic film material having substantial
resistance to tearing by overlapping side margins of the film and
heat sealing the same to provide a longitudinal seam, feeding a
tear strip between the overlapped side margins prior to the sealing
of the overlapped margins with the tear strip positioned relative
to the overlapped margins so that it spans the sealed area joining
the same and a side edge thereof projects beyond the seam a
sufficient distance to permit it to be readily grasped and pulled
back across the seam area so as to tear open the same, cutting a
pair of transverse slits in the tear strip which extend into the
outermost film margin so as to facilitate tearing either around the
tube or along the longitudinal seam, filling the tube with a
predetermined quantity of flowable product and closing off and
sealing the ends thereof with the ends of the tear strip extending
into the sealed ends of the tube.
2. A method of fabricating a package which comprises forming into a
continuous tube a web of relatively thin, plastic film material
having substantial resistance to tearing by overlapping side
marginal portions of the film material and heat sealing the same to
provide a longitudinal seam, feeding a continuous tear strip having
a tensile strength greater than the film material between the
overlapped side marginal portions of the film material prior to the
sealing of the overlapped marginal portions which tear strip has
sufficient width and is positioned relative to the overlapped
marginal film portions so that a portion of said tear strip is in
the longitudinal seam forming area and a side edge thereof projects
outside of said seam forming area a sufficient distance to permit
it to be readily grasped and pulled back across the seam thereby to
tear open the package, heat sealing the film and tear strip
material so as to connect the same in the longitudinal seam forming
area and leaving said side edge of the tear strip which projects
outside of said seam forming area free so that it may be readily
grasped, filling the tube with a predetermined quantity of flowable
product and closing off and sealing the ends thereof with the ends
of the tear strip extending into the sealed ends of the tube.
3. A method of fabricating a package as set forth in claim 2 and
feeding a tear strip between the side marginal portions of the film
material which is in the form of surface bonded laminations, and
sealing the outside laminations of said tear strip to the
overlapped marginal portions of the film material in the forming
the longitudinal seam.
Description
This invention relates to packaging and is more particularly
concerned with improvements in a method of fabricating a package of
plastic film with a tear strip means for facilitating opening of
the package.
Various types of packages have been developed for use in the
marketing of foodstuffs or similar products which are in a flowable
state. One package which is designed particularly for this purpose
is formed by feeding the product into a tube of relatively thin,
pliable plastic film material and closing the ends of the tube by
gathering and sealing the end portions of the tube with bendable
metal clips. One such package which has been employed successfully
for some time in the packaging of foodstuff, particularly,
comminuted meat products, spreads, cheese and the like, is
described in Pat. No. 2,831,302, granted to H. A. Jensen and A. H.
Eberman, on Apr. 22, 1958. In this package a film is employed which
generally has a relatively high resistance to tearing or puncturing
so as to withstand, without injury, the relatively rough handling
encountered in the marketing of the package. The package has a
longitudinal or axially extending seal formed in overlapping
margins of the film material which has been effected by the use of
electronic equipment resulting in the welding of the plastic film
along a relatively narrow line. When this package is formed from a
film having a low moisture transmitting characteristic, for
example, "Saran," which has been used extensively for packaging
meat products, the resultant package has a relatively long shelf
life and the product is not subject to rapid deterioration.
However, because of the resistance of the package film to tearing,
it is generally necessary for the consumer to cut or puncture the
film with a knife or other sharp instrument in order to open the
package. Various schemes have been proposed for providing this type
of package with tear strip or tear cord arrangements so as to
facilitate opening of the same but none of the arrangements
proposed have proven successful. For various reasons they have not
been acceptable to the manufacturers of this package or to the
consumers who use it. It has long been recognized that a
satisfactory device for facilitating the opening of this package
which would not require the use of any kind of a tool would make
the package more acceptable to the user and would be quickly
adopted by the manufacturers provided it did not increase the cost
unduly. A general object, therefore, of the present invention is to
provide a package of this character having an improved easy opening
feature which may be incorporated in the package without detracting
from its appearance and without an appreciable increase in the cost
of producing the same.
It is a more specific object of the invention to provide in a
package for a flowable product which is formed by overlapping and
sealing the margins of a film so as to provide a tube, filling the
tube with a flowable product and gathering and closing the same at
opposite ends by application of a bendable clip, an easy opening
device which is incorporated in the longitudinal seam and which is
so constructed that it facilitates opening the package by tearing
the packaging film either longitudinally along the seam or
transversely about the periphery of the tube.
A further object of the invention is to provide in a tubular
package having a longitudinal seam formed in overlapping margins of
the packaging film and with the ends gathered and closed by
bendable clips, an easy opening device which is in the form of a
tear strip interposed between the film margins forming the
longitudinal seam and extending the full length of the package with
its ends anchored by the end closure clips.
Another object of the invention is to provide a tubular package
having a relatively narrow, longitudinally extending seal formed in
overlapping margins of the packaging film and end seals formed by
gathering the tubular material and applying a bendable metal clip,
wherein a tear strip which is formed of a material having a tear
strength greater than the packaging film is interposed between the
overlapped film margins and sealed to the oppositely disposed faces
thereof with the tear strip extending the length of the package so
that the ends are anchored by the end closure clips and with a side
marginal portion extending outside of the seal forming area and
accessible so that it may be gripped and torn to break the seal and
open the package.
Still another object of the invention is to provide in a tubular
package having a longitudinal seal formed by overlapping marginal
portions of the packaging film, a longitudinally extending tear
strip interposed between the seal forming margins with the side
edge extending to the exterior of the package where it is
accessible so as to be gripped and pulled to tear the package open,
and spaced transverse slits in the exposed side edge of the tear
strip for facilitating the tearing of the packaging material either
transversely of the seam or longitudinally thereof.
These and other objects and advantages of the invention will be
apparent from a consideration of the package and the method of
forming the same which is shown by way of illustration in the
accompanying drawings wherein:
FIG. 1 is a perspective view illustrating a package of tubular form
which is fabricated according to the method of the present
invention and which has incorporated therein the principal features
of the invention;
FIG. 2 is a cross-sectional perspective, to an enlarged scale,
taken on the line 2-2 of FIG. 1;
FIG. 3 is a fragmentary cross section through the seal area, to a
still larger scale, the view showing the laminated tear strip
element employed in the package of FIG. 1;
FIG. 4 is a perspective view, largely schematic, illustrating the
method of forming the package of FIG. 1.
Referring to FIGS. 1 and 2 of the drawings, there is illustrated a
package 10 which has incorporated therein an easy opening device
embodying the principles of the invention.
The package 10 is in the form of a tube and is adapted to be
fabricated from a single length of plastic film 11. The particular
type of film employed will depend upon the nature of the product
which is to be packaged. When the product is processed meat, such
as, a sandwich spread or the like, the preferred packaging material
is "Saran" which is highly resistant to the transfer of moisture
and serves to retain the flavor in the product and resist
deterioration so as to provide a relatively long shelf life. Other
film materials may be employed such as "Pliofilm," polyethylene and
the like, depending upon the nature of the product and the
characteristics desired in the film.
In forming the package 10 the tubular shape is accomplished by
overlapping and sealing the side marginal portions 12 and 14 of the
film 11. In the package 10 illustrated in FIGS. 1 and 2, a
relatively narrow tear strip 15 is interposed between the
overlapped margins 12 and 14 of the film 11 and an "RF" or
electronic-type seal 16 joins the tear strip 15 to the overlying
and underlying film margins 12 and 14 throughout the length of the
package. The package 10 is closed at its opposite ends by gathering
the tube material and applying bendable clips 17 and 17' which may
be formed, for example, of a suitable metal such as aluminum. The
tear strip 15 extends the entire length of the package 10 so that
its ends are anchored in the end seals formed by the clips 17 and
17'.
Preferably, the tear strip 15 is formed as a laminate (FIG. 3) with
an interior ply 18 and exterior plies 20 and 20'. When the
packaging material is "Saran" the exterior plies 20 and 20' are
preferably the same material so as to readily seal with the
packaging film when the electronic sealing occurs as shown in FIG.
3. The inner ply 18 is chosen for its tensile strength and
resistance to the sealing action. A polyester film may be employed
with the "Saran" which is not affected by electronic sealing but
which may be surface bonded by heat or by other sealing methods to
the "Saran" so as to form a laminate. Other combinations of
materials may be employed with an adhesive bond between the plies
of the tear strip which will prevent delamination and with the
center ply unaffected by the seam sealing action so as to permit
tearing across the seal. The tear strip may be opaque, translucent
or a contrasting color, as desired.
To locate the point for the beginning of the tearing where desired
and to facilitate the start of the tearing action, particularly,
where the film material has substantial resistance to tearing, a
pair of slits 21 and 22 are cut in the exposed margin of the tear
strip 15 and adjacent portions of the outer film margin 12. The
slits 21 and 22 extend in a direction transversely of the
longitudinal axis of the tube and are of sufficient length to
extend into the margin of the packaging film but terminating short
of the seal 16, as shown in FIGS. 1 and 2. The material between the
slits 21 and 22, indicated at 23, may be grasped and pulled in the
direction of the seam or seal 16 to tear around the circumference
of the package for opening the same. If desired, the material may
be grasped adjacent the slit 21 in FIG. 1 and pulled in the
longitudinal direction across the longitudinal seam 16 to tear
along the latter for opening the package.
As illustrated in FIG. 4, the present package may be most
conveniently made by feeding a continuous web W of a film material
which is suitable for forming the package over the end of a hollow
mandrel M through which the product is fed, folding the web to
overlap side margins of the same and simultaneously feeding a
continuous web T of the tear strip material between the overlapped
film margins with the one side edge extending beyond the outside
lap of the film material, sealing the multiply material formed by
the overlapped film margins and the tear strip by means of an
electronic sealing mechanism, indicated at S, so as to provide a
continuous longitudinal seam, applying pairs of transverse slits 21
and 22 at the proper intervals by means of a slitting knife and
cooperating anvil assembly, indicated at C, constricting the filled
tube at intervals after it advances beyond the discharge end of the
mandrel M, applying pairs of the closure clips 17, 17' to the
constricted sections of the tube and cutting between the clips 17
and 17' of each pair thereof. These operations may be carried out
mechanically by proper modification of the package forming machine
disclosed in Pat. No. 2,831,302 so as to feed the tear strip and
place the slits 21 and 22 in the proper location.
While particular materials and specific structural details have
been referred to in describing the package illustrated and the
method and apparatus for forming the same, it will be understood
that other suitable materials and equivalent structural details may
be resorted to within the spirit of the invention.
* * * * *