Package making – With cover-adjunct application or formation – Adjunct comprising provision to allow access to contents,...
Reexamination Certificate
1999-09-07
2003-12-23
Sipos, John (Department: 3721)
Package making
With cover-adjunct application or formation
Adjunct comprising provision to allow access to contents,...
C053S139400, C053S374800, C053S552000, C053S201000
Reexamination Certificate
active
06665999
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a reclose or zipper seal jaw design for use in a sealing carriage of a vertical form and fill packaging machine, and, in particular, to a quick-change, reclosable zipper seal jaw module and standard or “return” module that can accommodate variable bag sizes. The modules are self-aligning, easily installed on existing bridge assembly hardware, and incorporate several safety enhancements.
2. Description of Related Art
Vertical form, fill, and seal packaging machines are commonly used in the snack food industry for forming, filling, and sealing bags of chips and other like products. Such packaging machines take a packaging film, such as polypropylene, from a sheet roll of said film, and forms the film into a vertical tube around a product delivery cylinder. The vertical tube is vertically sealed along its length to form a back seal. The machine applies a pair of heat-sealing jaws or facings against the tube to form a transverse seal. This transverse seal acts as the top seal on the bag below and the bottom seal on the package being filled and formed above. After the seal has been formed, the film tube is pushed downward to draw out another package length. The package below the transverse seal is separated by cutting across the sealed area.
Before each transverse seal is formed by the sealing jaws, the product to be packaged is dropped through the product delivery cylinder and formed tube and is held within the tube above the bottom transverse seal. Prior to forming the upper transverse seal, the sealing jaws are brought together in two steps. First, a pair of stripping plates or bars are brought into contact with the film in order to flatten the tube and strip product out of the area to be sealed. Second, the final closing movement of the jaws is performed, thereby forming the transverse seal.
The bag sealing functions of a vertical form, fill, and seal machine are best described with reference to
FIGS. 1
a
and
1
b.
FIG. 1
a
shows a sealing carriage on a prior art form, fill, and seal packaging machine.
FIG. 1
b
is a cross-section of a prior art facing assembly installed in said carriage. Opposed transverse seal jaw facings
102
,
104
(hereinafter referred to by Applicants as “jaw facings”) are shown attached to opposed bridge assemblies
106
,
108
. Behind each jaw facing
102
,
104
is a heat probe
128
,
130
capable of heating the exposed surface of the jaw facings up to 405° F. during operation. Placed between the jaw facings
102
,
104
and their respective bridge assemblies
106
,
108
is a heat separator
136
,
138
. The heat separators
136
,
138
provide a thermal barrier between the jaw facings
102
,
104
and the bridge assembly
106
,
108
in order to minimize heat transfer to the bridge assembly
106
,
108
and other components attached thereto. A thermocouple or thermoster
132
,
134
is placed between the heat separator
136
,
138
and the heat probe
128
,
130
in order to monitor the jaw facing
102
,
104
temperature. As previously described, a transverse seal is formed when a tube of film placed between the jaw facings
102
,
104
is flattened as the jaw facings
102
,
104
are brought in close proximity to each other. This is accomplished by both bridge assemblies
106
,
108
traversing towards each other while riding on two stationary rods
110
,
112
.
Also shown attached to the bridge assemblies
106
,
108
are a pair of opposed crumb plates
114
,
116
. When the bridge assemblies
106
,
108
are brought together, the crumb plates
114
,
116
slightly overlap, thereby forming a temporary “S” shaped constriction in the flattened film tube. This “S” shaped constriction provides a means for keeping product out of the transverse seal area while the tube of film above the constriction is filled with product. Two stripper bars
118
,
120
are also shown attached to the bridge assemblies
106
,
108
. The stripper bars
118
,
120
are typically spring loaded and provide the stripping function previously described.
Both of the jaw facings
102
,
104
are constructed with a central channel
141
,
143
to accommodate a knife or cutting tool
122
. This knife
122
is recessed within the channel
141
of one of the jaw facings
102
and held in place by two knife brackets
124
,
126
attached to the bridge assemblies
106
,
108
. After the transverse seal has been formed on the flattened film tube, the knife brackets
124
,
126
are rotated slightly, thereby exposing the knife
122
to the transverse seal. This action cuts the transverse seal, thereby completing the process of forming, filling, and sealing a single package.
The prior art carriage described above is designed such that the jaw facings
102
,
104
can be removed in order to install jaw facings
102
,
104
that provide for different vertical widths of the resultant transverse seals. The facing assembly shown in
FIG. 1
b
is aligned at the factory, and removal from the sealing carriage by the operator of more than the jaw facings
102
,
104
, crumb plates
114
,
116
, and stripper bars
118
,
120
is not recommended. Such design is also not easily adapted to the formation of a zipper seal along with the standard transverse seal. In fact, as will be explained below, a form, fill, and seal packaging system must be substantially modified when it is used to install a zipper seal at the top of the package.
A zipper seal is a resealable barrier that can be installed on the top end of a bag either immediately below or above the upper transverse seal. After the consumer breaks the upper transverse seal to gain access to the product within the package, the zipper seal can be reclosed, thereby keeping the product fresh. Such package is referred to as a “reclose” bag. Consequently, the terms “zipper seal module” and “reclose module,” and many other descriptive terms using as adjectives the words “zipper” or “reclose,” are used herein by Applicants interchangeably.
FIGS. 2
a
and
2
b
show one embodiment of a reclose food package
281
incorporating a zipper seal
283
.
FIG. 2
a
is a perspective view of a flexible, plastic package or bag
281
used to contain potato chips, tortilla chips, and the like.
FIG. 2
b
is a cross-section of the top of said bag
281
. The food package
281
shown is typical in that it has an upper transverse seal
285
and a lower transverse seal
287
. However, this bag also uniquely incorporates a zipper or reclose seal
283
immediately below the upper transverse seal
285
. The zipper seal
283
is made up of a male engagement member
291
and a female engagement member
289
.
For the embodiment illustrated, the package
281
is opened for the first time by pulling on the exterior walls of the package
281
below the zipper seal
283
. The two opposed members
289
,
291
separate, thereby opening the zipper seal
283
. Stress can then be exerted on the upper transverse seal
285
until it opens. Once this occurs, the package
281
is fully opened and the product, such as tortilla chips
293
, may be consumed. The package
281
can then be resealed by applying pressure to the exterior of the package
281
along the zipper seal
283
, thereby forcing the male engagement member
291
back into the female engagement member
289
. This novel reclose bag design is described in detail in U.S. patent application Ser. No. 09/079,382 filed on May 15, 1998 now U.S. Pat. No. 5,972,386.
When making the reclose bag
281
illustrated, the opposed members
289
,
291
(of the zipper seal
283
) must be heat sealed to the inside surface of the food package
281
. Further, these opposed members
289
,
291
must be heat-sealed together at each end
295
,
297
. This is accomplished by applying a heat and pressure sealing device to an outer areas of the zipper seal
283
.
The film that enters a form and fill machine to form the reclose package
281
shown in
FIG. 2
a
is typically a continuous sheet with graphics presented on one side. The side of the sheet on which the graphics
Dierl Martin Bernhard
Edwards Eduard
Cahoon Colin P.
Carstens Yee & Cahoon, L.L.P.
Recot Inc.
Sipos John
LandOfFree
Seal jaw modules for reclose bag modification to vertical... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Seal jaw modules for reclose bag modification to vertical..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Seal jaw modules for reclose bag modification to vertical... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3168606