U.S. patent application number 10/369964 was filed with the patent office on 2004-08-19 for methods for manufacturing package strips.
Invention is credited to Matthews, David J..
Application Number | 20040159075 10/369964 |
Document ID | / |
Family ID | 32736437 |
Filed Date | 2004-08-19 |
United States Patent
Application |
20040159075 |
Kind Code |
A1 |
Matthews, David J. |
August 19, 2004 |
Methods for manufacturing package strips
Abstract
Various methods for making package strips having a number of
individual packages of a consumer product and separable from one
another by perforations are disclosed. The individual packages have
reclosable plastic zippers, which are applied during the
manufacture of the package strips either transversely or lengthwise
onto the sheet of polymeric film material from which the packages
are fashioned.
Inventors: |
Matthews, David J.; (Gilman,
IL) |
Correspondence
Address: |
PITNEY HARDIN LLP
7 TIMES SQUARE
NEW YORK
NY
10036-7311
US
|
Family ID: |
32736437 |
Appl. No.: |
10/369964 |
Filed: |
February 19, 2003 |
Current U.S.
Class: |
53/412 ;
53/450 |
Current CPC
Class: |
B65B 61/188
20130101 |
Class at
Publication: |
053/412 ;
053/450 |
International
Class: |
B65B 061/18; B65B
009/00 |
Claims
What is claimed is:
1. A method for manufacturing package strips having a preselected
number of individual packages of a consumer product, each of said
individual packages having a reclosable plastic zipper, said method
comprising the steps of: a) providing a top sheet of polymeric film
material and a bottom sheet of polymeric film material; b)
providing a supply of reclosable zipper strip; c) attaching
preselected lengths of said reclosable zipper strip, one for each
individual package being manufactured, transversely upon one of
said top and bottom sheets at package-length intervals thereon; d)
depositing a consumer product to be packaged on said bottom sheet
at package-length intervals thereon; e) covering said consumer
product with said top sheet; f) sealing said top sheet over said
consumer product; g) attaching said preselected lengths of said
reclosable zipper strip to the other of said top and bottom sheets;
h) making a cross seal on a side of said consumer product opposite
to said preselected length of reclosable zipper strip to form said
individual packages thereof; i) making perforations between each
pair of individual packages to enable said individual packages to
be separated from one another; and j) cutting between pairs of
individual packages at preselected intervals to obtain said package
strips having a preselected number of individual packages.
2. A method as claimed in claim 1 wherein step a) is performed by
providing a sheet of polymeric film material and by folding said
sheet lengthwise over said consumer product to form said top sheet
and said bottom sheet.
3. A method as claimed in claim 2 wherein two lateral edges of said
sheet are sealed to one another to seal said top sheet over said
consumer product.
4. A method as claimed in claim 1 wherein step a) is performed by
providing a sheet of polymeric film material and by folding both
lateral edges thereof toward one another over said consumer product
to form said top sheet and said bottom sheet.
5. A method as claimed in claim 4 wherein said two lateral edges
are sealed to one another with a fin seal to seal said top sheet
over said consumer product.
6. A method as claimed in claim 1 wherein step a) is performed by
supplying said top sheet separately from said bottom sheet.
7. A method as claimed in claim 1 further comprising the step of
activating a peel seal on said preselected lengths of reclosable
zipper strip.
8. A method as claimed in claim 2 wherein said preselected lengths
of said reclosable zipper strip extend for substantially one half
of the width of said sheet of polymeric film material.
9. A method as claimed in claim 4 wherein said preselected lengths
of said reclosable zipper strip extend for substantially one half
of the width of said sheet of polymeric film material.
10. A method as claimed in claim 6 wherein said preselected lengths
of said reclosable zipper strip extend for substantially the width
of said bottom sheet of polymeric film material.
11. A method as claimed in claim 1 further comprising the step of
providing said preselected lengths of said reclosable zipper strip
with sliders.
12. A method as claimed in claim 1 further comprising the step of
providing a peel seal between said top sheet and said bottom sheet
adjacent to said preselected lengths of reclosable zipper
strip.
13. A method as claimed in claim 1 wherein step f) is performed by
heated drive rolls.
14. A method as claimed in claim 1 wherein said preselected number
of individual packages in said package strips is in a range from
five to eight.
15. A method as claimed in claim 1 wherein said preselected number
of individual packages in said package strips is one.
16. A method for manufacturing package strips having a preselected
number of individual packages of a consumer product, each of said
individual packages having a reclosable plastic zipper, said method
comprising the steps of: a) providing a flow-wrap machine having a
conveyor for consumer products to be packaged, said conveyor having
a gap running lengthwise therealong; b) depositing a consumer
product on said conveyor at package-length intervals thereon; c)
providing a sheet of polymeric film material having two lateral
edges; d) providing a supply of reclosable zipper strip; e)
dispensing said reclosable zipper strip lengthwise over said gap in
said conveyor; f) dispensing said sheet of polymeric film material
lengthwise over said conveyor above said reclosable zipper strip
and said consumer products; g) wrapping said sheet of polymeric
film material lengthwise around said conveyor and said consumer
products; h) sealing said lateral edges of said sheet of polymeric
film material to one another on the underside of said conveyor; i)
sealing said reclosable zipper strip to said sheet of polymeric
film material above and below said conveyor along said gap therein;
j) making cross seals on each side of said consumer product to form
said individual packages thereof; k) making perforations between
each pair of individual packages to enable said individual packages
to be separated from one another; and l) separating pairs of
individual packages from one another at preselected intervals to
obtain said package strips having a preselected number of
individual packages.
17. A method as claimed in claim 16 wherein in step b) said
consumer product is deposited on said conveyor in side-by-side
pairs at package-length intervals on opposite sides of said gap in
said conveyor, wherein in step e) two reclosable zipper strips are
dispensed lengthwise over said conveyor between said consumer
products making up said side-by-side pairs, and further comprising
the step of perforating said sheet of polymeric film material
lengthwise between said two reclosable zipper strips to produce two
package strips side-by-side one another.
18. A method as claimed in claim 16 further comprising the step of
activating a peel seal on said reclosable zipper strip.
19. A method as claimed in claim 16 wherein in step h) said lateral
edges of said sheet of polymeric film material are sealed to one
another with a fin seal.
20. A method as claimed in claim 16 further comprising the step of
providing said reclosable zipper strip with sliders at
package-length intervals.
21. A method as claimed in claim 16 wherein said preselected number
of individual packages in said package strips is at least four.
22. A method as claimed in claim 16 wherein said preselected number
of individual packages in said package strips is one.
23. A method as claimed in claim 16 wherein step i) is performed by
heated drive rolls.
24. A method as claimed in claim 16 wherein step i) is performed by
a drag sealer.
25. A method as claimed in claim 16 wherein step i) is performed by
lengthwise seal bars.
26. A method as claimed in claim 16 wherein steps j) and k) are
performed by a pair of rotating seal bars.
27. A method as claimed in claim 16 wherein steps j) and k) are
performed by upper and lower rows of cross seal bars.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to reclosable plastic packages
of the variety in which consumer products are packaged for retail
sale. More particularly, the present invention relates to strips of
packages wherein individual packages making up the strip are
separable from one another by perforations therebetween.
[0003] 2. Description of the Prior Art
[0004] The present invention relates to improvements in the
package-making art and may be practiced in the manufacture of
thermoplastic bags and packages of the kind that may be used for
various consumer products, but which are particularly useful for
food products which must be kept in moisture- and air-tight
packages, free from leakage until initially opened for access to
the product contents. The prior art is fairly well developed, but
nevertheless has aspects worthy of development and improvement.
[0005] In the present case, package strips made on horizontal
form-fill-and seal (HFFS) machines or on flow-wrap machines are
well known in the art. There has long been an interest in producing
strips of individual packages, wherein each individual package has
a reclosable plastic zipper. The present invention provides for
this need.
SUMMARY OF THE INVENTION
[0006] Accordingly, the present invention comprises methods for
manufacturing package strips having a preselected number of
individual packages of a consumer product. Each of the individual
packages has a reclosable plastic zipper. The methods fall into two
general categories. In one, lengths of reclosable zipper strip are
applied transversely onto a sheet of polymeric film material from
which the packages are being made on a horizontal
form-fill-and-seal (HFFS) machine. In the other, reclosable zipper
strip is applied lengthwise on an flow-wrap machine in which the
consumer products being wrapped pass down a conveyor.
[0007] In both general methods, the reclosable zipper strip is
sealed to what will be the top and bottom sheets of the package.
Optionally, a peel seal between the flange portions of the
reclosable zipper strip may be formed and activated.
[0008] Cross seals are formed between each individual package, and
perforations made to enable the individual packages to be separated
form one another. The package strips, comprising any number of
individual packages, are formed by cutting or tearing them from the
downstream end of the manufacturing apparatus as desired.
[0009] The present invention will now be described in more complete
detail with frequent reference being made to the drawings
identified as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic view of an apparatus for manufacturing
package strips whose individual packages have transverse
zippers;
[0011] FIG. 2 is a cross-sectional view of a zipper-application
station for the apparatus shown in FIG. 1;
[0012] FIG. 2A is a cross-sectional view of an alternate
zipper-application station for zippers having sliders;
[0013] FIG. 3 is a perspective view of a sheet of polymeric film
material passing over a folding board in the apparatus shown in
FIG. 1;
[0014] FIG. 3A is an enlarged view of the indicated portion of FIG.
3;
[0015] FIG. 4 is a schematic cross-sectional view of the
cross-sealing, perforating and cutting stations of the apparatus
shown in FIG. 1;
[0016] FIG. 4A is a schematic cross-sectional view, analogous to
that of FIG. 4, for the case where the zippers have sliders;
[0017] FIG. 5 is a schematic cross-sectional view of the same
stations as are shown in FIG. 4 where the zipper has a peel
seal;
[0018] FIGS. 5A and 5B are enlarged views of the indicated portions
of FIG. 5;
[0019] FIG. 6 is a schematic view of another apparatus for
manufacturing package strips whose individual packages have
transverse zippers;
[0020] FIG. 7 is a schematic view of still another apparatus for
manufacturing package strips whose individual packages have
transverse zippers;
[0021] FIG. 8 is a schematic view of an apparatus for manufacturing
package strips whose individual packages have lengthwise
zippers;
[0022] FIG. 9 is a schematic view of another apparatus for
manufacturing package strips whose individual packages have
lengthwise zippers;
[0023] FIG. 10 is a schematic view of still another apparatus for
manufacturing package strip whose individual packages have
lengthwise zippers; and
[0024] FIG. 11 is a schematic view of yet another apparatus for
manufacturing package strips whose individual packages have
lengthwise zippers.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Turning now to these figures, FIG. 1 is a schematic view of
an apparatus for practicing the method for manufacturing the
package strips of the present invention. Apparatus 10 comprises a
drive roller 12 and a companion roller 14 forming a nip therewith
for supplying a sheet 16 of polymeric film material in
package-length increments from a supply roll 18 thereof. The sheet
16 proceeds to zipper-application station 20 which applies lengths
of reclosable zipper strip 22 transversely onto sheet 16 at
package-length intervals from a supply not shown.
[0026] FIG. 2 is a cross-sectional view of zipper-application
station 20. The station 20 comprises a zipper guide 24 which pivots
counterclockwise around hinge 26, when urged to do so by spring 28,
to release a length of reclosable zipper strip 22 which has been
attached to sheet 16. It will be appreciated by those of ordinary
skill in the art that zipper guide 24 is but an example of those
known in the art and useful for the practice of the present
invention. The station 20 also comprises a first seal bar 30 and a
second seal bar 32, one on each side of the sheet 16, for attaching
the length of reclosable zipper strip 22 thereto.
[0027] Reclosable zipper strip 22 includes a male interlocking
profile 34 and a female interlocking profile 36. The former
includes a male interlocking member 38, perhaps having an
arrowhead-shaped cross section as shown in FIG. 2, and a flange 40
integrally formed therewith. The latter includes a female
interlocking member 42, perhaps comprising two inwardly curving
members having barbed edges and defining a channel as shown in FIG.
2, into which male interlocking member 38 snappingly engages, and a
flange 44. The mutually facing surfaces of flanges 40,44 may have
ridges 48 to facilitate gripping when a package having reclosable
zipper strip 22 is being opened. It should be understood that
reclosable zipper strip 22 is an example of the strips that may be
used in practicing the present invention, and that the present
invention is not to be construed to be limited to such a specific
zipper design.
[0028] First seal bar 30 and second seal bar 32 seal the length of
reclosable zipper strip 22 to film 16, and optionally form a peel
seal between the two flanges 40,44. Specifically, the upper portion
50 of first seal bar 30 is rubber, while the upper portion 52 of
second seal bar 32 is heated so that, when the first and second
seal bars 30,32 clamp together, flange 44 is sealed to sheet 16
without being sealed to flange 40 as well. The first and second
seal bars 30,32 may also have lower portions 54,56, respectively,
which activate an optional peel seal 58 between flanges 40,44. Peel
seal 58, alternatively, may be formed during the manufacture of the
reclosable zipper strip 22.
[0029] FIG. 2A is a cross-sectional view of an alternate zipper
application station 20' for use where the reclosable zipper strip
22' has a slider 49. Elements appearing in both FIGS. 2 and 2A have
the reference numbers used in FIG. 2, and the descriptions thereof
given above are equally applicable for them in FIG. 2A. Reclosable
zipper strip 22' in FIG. 2A has a slider 49, which separates the
male and female interlocking profiles 34,36 from one another when
moved in one direction along zipper strip 22', and joins them
together when moved in the other direction. Zipper guide 25 is
modified, relative to zipper guide 24 in FIG. 2, to accommodate
slider 49.
[0030] Referring back to FIG. 1, individual lengths 60 of
reclosable zipper strip 22 are attached transversely to film 16 at
package-length intervals. The individual lengths 60 extend for
approximately one half of the width of the sheet 16, and, in the
schematic view of FIG. 1, are attached adjacent to one of the two
lateral edges of the sheet 16. Proceeding along in the direction of
travel of sheet 16 from zipper-application station 20, sheet 16
passes through a dancer 62 which accumulates sheet 16 so that its
incremental motion past zipper-application station 20 is converted
to a continuous motion.
[0031] Sheet 16 continues from dancer 62 to folding board 64. FIG.
3 is an enlarged view of folding board 64 and of sheet 16 passing
thereover, and FIG. 3A is a further enlarged view of the indicated
portion of FIG. 3. Folding board 64 extends for half the width of
the sheet 16, namely the half having the individual lengths 60 of
reclosable zipper strip 22, or of reclosable zipper strip 22'
having slider 49, attached thereto, and changes the direction of
travel of the sheet 16 by 90.degree.. As a consequence, the half of
the sheet 16 not supported by the folding board 64 becomes slack,
enabling it to be folded over the half having the individual
lengths 60 of reclosable zipper strip 22. The consumer product 63
being individually packaged is deposited on the sheet 16 in the
amounts intended for each individual package between each
individual length 60 of reclosable zipper strip 22 on or adjacent
to folding board 64, such as at point 65, so that the sheet 16 is
folded over the consumer product 63. It should be noted that the
sheet 16 could alternatively be folded by other methods known to
those of ordinary skill in the art and not requiring a 90.degree.
change in direction of travel to accomplish the folding.
[0032] FIG. 3A provides a perspective view of the end of an
individual length 60 of reclosable zipper strip 22 as attached to
sheet 16. As illustrated, individual length 60 extends for
approximately one half of the width of the sheet 16, and does not
quite extend to the lateral edge 66 of the sheet 16. The optional
slider 49 is also shown in FIG. 3A.
[0033] Returning again to FIG. 1, as the sheet 16 is being folded
longitudinally by folding board 64, lateral edge 68 is brought over
and on top of lateral edge 66. Heated drive rolls 70, somewhat
downstream from folding board 64, carry out two functions. Firstly,
they drive sheet 16 at a constant rate, pulling it over the folding
board 64 so that it may be folded as required. Secondly, heated
drive rolls 70 seal the folded sheet 16 along lateral edges 66,68
and optionally along crease 72.
[0034] Downstream from heated drive rolls 70 are three additional
stations for completing the manufacture of the package strips.
Referring to FIG. 4, seal station 74 seals flange 40 of reclosable
zipper strip 22 to the half of sheet 16 which has been folded over
by folding board 64.
[0035] Seal station 74 comprises a heated seal bar 76 and an
unheated seal bar 78. Both bars 76,78 rotate as indicated by the
curved arrow adjacent thereto, bar 76 rotating in a
counterclockwise sense and bar 78 rotating in a clockwise sense.
Each makes one half of a complete rotation in the time required for
one of the individual packages to pass thereby, it being recalled
that the sheet 16 is moved at a constant rate by heated drive rolls
70, and does not come to a stop at seal station 74 or at the other
two stations whose function is to be discussed below. The rotation
is synchronized such that the bars 76,78 are oriented vertically,
as shown in FIG. 4, as the reclosable zipper strip 22 arrives so
that the intended sealing can occur.
[0036] It is to be noted that unheated seal bar 78 has
silicone-rubber pads 80 at each end to apply pressure, but not
heat, to flange 44 while heated seal bar 76 seals sheet 16 to
flange 40. This is intended to prevent flanges 40,44 from being
sealed to one another.
[0037] One package length downstream is another station, which
seals the bottom of each individual package and provides
perforations to enable the individual packages to be separated from
one another. Specifically, seal/perforation station 82 comprises a
first and a second heated seal bar 84,86, the former including a
perforator 88. Both bars 84,86 rotate as indicated by the curved
arrows adjacent thereto, bar 84 rotating in a counterclockwise
sense and bar 86 rotating in a clockwise sense. Each makes one half
of a complete rotation in the time required for one of the
individual packages to pass thereby, as was the case with bars
76,78. Again, the rotation is synchronized such that the bars 84,86
are oriented vertically, as shown in FIG. 4, as the reclosable
zipper strip 22 arrives so that the intended sealing and
perforating can occur. Seal bars 84,86 provide a bottom seal 90 for
each individual package, and perforator 88 provides perforations so
that each individual package can be separated from the next.
[0038] A further package length downstream is yet another station
which cuts the package strips being manufactured to a desired
length comprising some preselected number of individual packages.
The preselected number may be any number, including one. As such,
cutting station 92 comprises first and second bars 94,96, the
former including a cutting knife 98. Both bars 94,96 rotate as
indicated by the curved arrows adjacent thereto, bar 94 rotating in
a counterclockwise sense and bar 96 rotating in a clockwise sense.
Each makes one half of a complete rotation in the time required for
the preselected number of individual packages desired for the strip
to pass thereby, at which time cutting knife 98 cuts the strip 100
from the rest of the individual packages, each containing consumer
product 63, being manufactured.
[0039] FIG. 4A is a schematic cross-sectional view, analogous to
that of FIG. 4, for the case where the reclosable zipper strips 22'
have sliders 49. When comparing FIGS. 4 and 4A with one another, it
will be noted that the consumer product 63 being packaged is
downstream of the reclosable zipper strip 22' for a given package
in FIG. 4A, while it was upstream of the reclosable zipper strip 22
in FIG. 4. The significance of this difference between FIGS. 4 and
4a will become apparent in the discussion to follow.
[0040] As in FIG. 4, seal station 74 comprises heated seal bar 76
and unheated seal bar 78. Seal station 74 functions in the same
manner as described above to seal sheet 16 to flange 40 without
sealing flanges 40,44 to each other.
[0041] Downstream from seal station 74 in FIG. 4A is
seal/perforation station 82', which differs from seal/perforation
station 82 in FIG. 4. Seal/perforation station 82' seals the
bottoms of the individual packages being manufactured, provides
perforations to enable the individual packages to be separated from
one another, and optionally activates a peel seal at the tops of
the individual packages. Specifically, seal/perforation station 82'
comprises first and second heated seal bars 84',86', the latter
including a perforator 88'. As in seal/perforation station 82 in
FIG. 4, seal bars 84',86' rotate in the directions indicated,
making one half of a complete revolution in the time required for
one of the individual packages to pass by station 82'. The upstream
portions of first and second seal bars 84',86' provide a bottom
seal 90 for each individual package, perforator 88' provides
perforations so that each individual package can be separated from
that preceding it, and the downstream portions of the first and
second seal bars 82',84', which do not meet one another as closely
as the upstream portions which form bottom seal 90, may activate an
optional peel seal 91 at the top of the preceding package. It
should be understood that the perforations and optional peel seal
91 in an individual package give a consumer access to slider 49 so
that the individual package may be opened by manipulation
thereof.
[0042] Cutting station 92 is one package length downstream from
seal/perforation station 82', and is as described above for FIG. 4.
Cutting knife 98 cuts the strip 100, seen in FIG. 1, from the rest
of the individual packages, each containing consumer product 63,
being manufactured between bottom seal 90 and optional peel seal
91.
[0043] FIG. 5 shows the same stations as are shown in FIG. 4 for
the case where flanges 40,44 of reclosable zipper strip 22 are
joined to one another with peel seal 58. FIGS. 5A and 5B are
enlarged views of the indicated portions of FIG. 5. In all other
respects, a discussion of FIGS. 5, 5A and 5B would be identical to
that above for FIG. 4 and, as such, it will not be repeated here.
Further, reclosable zipper strip 22', having a peel seal 58 and a
slider 49, could also be used in the manufacture of reclosable
packages in the manner illustrated in FIG. 4A.
[0044] FIG. 6 is a schematic view of an apparatus slightly
different from that shown in FIG. 1 for practicing the method for
manufacturing the package strips of the present invention.
Apparatus 110 is substantially the same as apparatus 10.
Accordingly, the preceding discussion applies to apparatus 110, and
elements in FIG. 6 to which the preceding discussion equally
applies will be given the same drawing reference numbers as appear
in FIG. 1, except to the extent described below.
[0045] Referring to FIG. 6, and comparing it to FIG. 1, it will be
immediately apparent that zipper-application station 20 still
applies individual lengths 60 of reclosable zipper strip 22 to film
16 at package-length intervals, but that, instead of being applied
adjacent to one of the two lateral edges 66,68 of the sheet 16,
they are centered with respect to the lateral edges 66,68.
Moreover, downstream from dancer 62, the lateral edges 66,68 are
folded toward one another and sealed together with a fin seal 114
by heated drive rolls 112, which also drive the sheet 16 at a
constant rate. In all other respects, apparatus 110 is the same as
apparatus 10. That is to say, downstream from the heated drive
rolls 112, the manufacture of package strip 100 is completed by
seal station 74, seal/perforation station 82 and cutting station
92, as previously described.
[0046] FIG. 7 is a schematic view of still another apparatus for
practicing the method for manufacturing the package strips of the
present invention. Apparatus 120 is much the same as apparatuses
10,110, and elements appearing in FIG. 7 to which the preceding
discussion equally applies will be given the same drawing reference
numbers as are used in FIGS. 1 and 6, and will not be described
again.
[0047] Referring, now, to FIG. 7, apparatus 120 produces package
strips using two supplies of plastic film material rather than one
which must be folded over the consumer product being packaged.
Specifically, apparatus 120 uses a top sheet 122 of polymeric film
material dispensed from a supply roll 124 and a bottom sheet 126 of
polymeric film material dispensed from a supply roll 128.
[0048] Turning first to the top sheet 122, this sheet may be fed or
dispensed from supply roll 124 in package-length increments and
lengths of reclosable zipper strips attached transversely thereto
at some point, such as point 130, before dancer 62, which converts
the incremental motion of the top sheet 122 to continuous motion
driven by heated drive rolls 70. Length 132 of reclosable zipper
strip, applied using a zipper-application station like that shown
in FIGS. 1 and 6 but not included in FIG. 7, extends for
substantially the full width of top sheet 122 between its lateral
edges 134,136.
[0049] Bottom sheet 126, fed from supply roll 128, proceeds at a
constant rate to a point, such as point 138, where a consumer
product 139 may be placed thereon at package-length intervals.
Bottom sheet 126 has lateral edges 140,142 which are sealed to
lateral edges 134,136, respectively, by heated drive rolls 70.
Thereafter, the manufacture of package strip 100 is completed by
seal station 74, seal/perforation station 82 and cutting station
92, as previously described.
[0050] FIGS. 8 through 11 are schematic views of additional
apparatuses for practicing the method for manufacturing the package
strips of the present invention. The main difference between these
additional apparatuses and those already discussed above is that
reclosable zipper strips run longitudinally on the sheet of
polymeric film material, rather than transversely, during the
manufacturing of the package strips. The additional apparatuses can
all be classified as flow-wrap machines.
[0051] Specifically, referring to FIG. 8, apparatus 150 includes a
spool 152 from which reclosable zipper strips 154 are continuously
dispensed. Although not shown in FIG. 8, it is within the scope of
the present invention to provide reclosable zipper strips 154 with
sliders at package-length intervals. A sheet 156 of polymeric film
material is dispensed from a supply roll 158 over and onto a
conveyor 160 which carries the consumer products 162 being packaged
in two rows, individual consumer products in each row being
side-by-side with those in the other and separated from those in
the same row by a package-length interval. Conveyor 160 has a gap
161 running down its center for a purpose to be explained below.
Consumer products 162 are deposited on conveyor 160 at points 163
at the beginning thereof.
[0052] The sheet 156, with two reclosable zipper strips 154 beneath
it, wraps around the conveyor 160 and consumer products 162, its
two lateral ledges 164,166 being joined to one another by a fin
seal, like that shown in FIG. 6, on the underside of the conveyor
160. Heated drive rolls 170 drive the sheet 156 continuously
through the apparatus 150, sealing the reclosable zipper strips 154
to the sheet 156 above and below the conveyor 160 and activating
any peel seals that may be included on the reclosable zipper strip
154, the gap 161 down the center of the conveyor 160 being provided
for this purpose. Perforator 172, mated with a roll 174 through the
same gap, perforates the sheet 156 down the center to enable the
two package strips 176 being manufactured to be separated
lengthwise from one another.
[0053] Downstream from perforator 172 is a seal/perforation station
178 similar to seal/perforation station 82 shown in FIGS. 3 and 4
and discussed above. Seal/perforation station 178 comprises a first
and a second heated seal bar 180,182, one of which includes a
perforator. Both bars 180,182 rotate as indicated by the curved
arrows adjacent thereto, bar 180 rotating in a counterclockwise
sense and bar 182 rotating in a clockwise sense. Each makes one
half of a complete rotation in the time required for one of the
individual packages being manufactured to pass thereby. The
rotation is synchronized such that the bars 180,182 are oriented
vertically, as shown in FIG. 8 as the lengthwise gap separating
consumer products 162 arrives at the seal/perforation station 178
so that the downstream seal for one individual package, the
upstream seal of the preceding package, and the perforation between
them can be made. The package strips 176 can then be made any
desired number of individual packages long, including one single
package long, by tearing them from apparatus 150 at the appropriate
frequency.
[0054] Referring, now, to FIG. 9, apparatus 190 is similar to
apparatus 150 of FIG. 8. Elements appearing in FIG. 9 identical to
those of apparatus 150 have been given the same drawing reference
numbers as appear in FIG. 8 and will not be described again.
[0055] Apparatus 190 differs from apparatus 150 in the manner in
which the sheet 156 of polymeric film material is driven through
the apparatus and sealed to reclosable zipper strips 154. Instead
of heated drive rolls 170, apparatus 190 includes a drag sealer 192
which seals the reclosable zipper strips 154 to the sheet 156 above
and below the conveyor 160 and activates any peel seals that may be
included on the reclosable zipper strip 154, the gap 161 down the
center of the conveyor 160 being provided for this purpose.
Downstream from the drag sealer 192 are a pair of drive rolls 194
which drive the sheet 156 continuously through the apparatus 190.
In other respects, apparatus 190 is identical to apparatus 150.
[0056] Apparatus 200, shown schematically in FIG. 10, is similar to
apparatus 150 of FIG. 8. Heated drive rolls 170 drive the sheet 156
continuously through the apparatus 200, sealing the reclosable
zipper strips 154 to the sheet 156 above and below the conveyor 160
and activating any peel seals that may be included on the
reclosable zipper strip 154, the gap 161 down the center of the
conveyor 160 being provided for this purpose.
[0057] In apparatus 200, seal/perforation station 204 takes the
place of seal/perforation station 178 in apparatus 150.
Seal/perforation station 204 includes an upper row 206 of four seal
bars 208 and a lower row 210 of four seal bars 212. Seal bars 208
or seal bars 212 include a perforator to perforate the cross seal
being made between each individual package being manufactured.
[0058] Upper row 206 and lower row 210 travel in mirror-image,
four-step cycles following rectangular, or D-shaped, paths as
suggested by the arrows above and below them, respectively.
Initially, upper row 206 and lower row 210 clamp together to apply
cross seals and perforations to four consecutive side-by-side pairs
of individual packages, and, remaining clamped together, move
downstream with them for a time sufficient to make the seals, as
the sheet 156 is being driven continuously by heated drive rolls
170. The upper row 206 and lower row 210 then separate from one
another, and move upstream four-package-length intervals to
complete the cycle and to begin the next one.
[0059] In apparatus 220, shown schematically in FIG. 11,
seal/perforation station 222 applies cross seals and perforations,
drives the sheet 156, and, in addition, seals the reclosable zipper
strips 154 to the sheet 156 on both sides of the packages and
activates any peel seals that may be included on the reclosable
zipper strips 154.
[0060] As above, elements of apparatus 220 which are identical to
those previously described for FIG. 8 will not be redescribed, and
have been given the same drawing reference numbers in FIG. 11. As
for seal/perforation station 222, this station comprises an upper
row 224 of five cross-seal bars 226 and a lower row 228 of five
cross-seal bars 230. Cross-seal bars 226 or cross-seal bars 230
include a perforator to perforate the cross seal being made between
each individual package being manufactured.
[0061] In addition, the upper row 224 and the lower row 228 include
four lengthwise seal bars 232, two of which seal the reclosable
zipper strips 154 to the sheet 156 on each side of the individual
packages, while the other two activate any peel seals that may be
included on reclosable zipper strips 154.
[0062] Upper row 224 and lower row 228 travel in mirror-image,
four-step cycles following rectangular, or D-shaped, paths as
suggested by the arrows above and below them, respectively.
Initially, upper row 224 and lower row 228 clamp together to apply
cross seals and perforations, as well as to attach the reclosable
zipper strips 154 and to activate any peel seals which may be
provided, to five consecutive side-by-side pairs of individual
packages. Then, remaining clamped together, upper row 224 and lower
row 228 pull sheet 156 downstream by an amount equal to five
package lengths. The upper row 224 and lower row 228 then separate
from one another, and move upstream five package lengths to
complete the cycle and to begin the next one.
[0063] Modifications to the above would be obvious to those of
ordinary skill in the art, without bringing the invention so
modified beyond the scope of the appended claims.
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