Note: Descriptions are shown in the official language in which they were submitted.
8743
SPECIFICA~ION
Thi~ ln~entlon relat~- to the ~t of b~g~ equlpped
wlth r~olo3able oxtruded ~l~sti~ zlpper~.
~ hereto~ore aon4truot~d, extruded zlpp~r equipp~
~g~ h~v0 gen-r~lly be~n provided wtth ~epAr~t~ zipper
strips having complementary profiles whioh are ~epar~ble
enterenga~ab1e. ~hl~ has req~lr~d producing and han~llng
two sep~rate zlpper ~trlp~ ln the bag makln~ ~rooe~s ~here
the str~p~ are ~parably formed and attaohed to the bsg body
~heet or web materlal. On the other h~nd, where the
proflle are lntegrally extr~ded wlth the fll~, lt ha~ been
req~ire~ to extrude ~eparate complementary proflle portlon~
of the zlpper on ~epar~te panels or p~nel portlons of a bag
maklng ~ilm.
ln a recent development a~ covered ~n the
eopen~ing ~pplicstlon o Ch~l~tof~ and Au~nit, Cane~l~n
Serlal No. 508,374, ~ d M~y 5, 1986, ~nd a~lgned to the
sama a~lgnee as the present ~ppllcation, it has been
propo~ed to provld~ zlpp~r8 form~d ~rom extrud~ proflled
continuou strlp~ folded upon themselves 80 that the
proflles on the folded 8tr~ p portlon~ lnterlock to provl~e
reclogable zlpperg for ~ag8. In th~t ~ppllo~tion it ha~
also been proposed to notch out the zipper profllcs ~t the
fold in the ~ip to facilltate folding o~ the zlpper strip
portions upon t~em~elve~. HowevAr, there has been ~ome
`~.;
12~374;3
problem at the zipper fold in that memory factor of the
plastic material tends to spread the fold which may
cause a leakage problem at that point. Such leakage
may be either of contents from within the bag, or
intrusion of foreign matter including air into the bag.
It is therefore an object of the present
invention to gain the advantages of the folded zipper
concept and cure the open fold problem.
Another object of the invention is to provide
a folded zipper arrangement having means for
restraining opening of the zipper due to pressures
generated within the associated b2g.
Still another object of the invention is to
provide new and improved means in a reclosable zipper
structure for identifying correct assembly of the
zipper with bag forming material.
In a desirable embodiment, the present
invention provides a bag having confronting bag body
wall panels, opposite side edges, a bottom end and a
top end, and including a reclosable zipper sandwiched
between the wall panels and extending between the side
edges adjacent to said top end. The zipper comprises a
continuous length of extruded profiled plastic strip
having a plurality of spaced parallel profile parts and
being folded upon itself to provide two parallel strip
portions extending from a fold. One of said strip
portions is attached to one of the wall panels, and the
~j8743
other strip portion, which is a continuation of said one
strip portion, is attached to the other of the wall panels.
The profile parts on the strip portions are releasably
interlockable for closing the top end of the bag. The fold
is located at one of the side edges. The strip portions are
spot sealed together at the fold.
The present invention also provides a method of making
a bag having confronting bag body wall panels, opposite side
edges, a bottom end and a top end, and including providing a
reclosable zipper between said wall panels and extending
between side edges adjacent to said top end, said zipper
comprising a continuous length of extruded profiled plastic
strip having a plurality of spaced parallel profile parts
and being folded upon itself to provide two parallel strip
portions extending from a fold, attaching one of said strip
portions to one of said wall panels and attaching the other
strip portion to the other of said wall panels, releasably
interlocking the profile parts on said one strip portion
with the profile parts on the other strip portion for
closing said top end of the bag, locating said fold at one
of said side edges, and spot sealing said strip portions
together at said fold.
ON THE DRAWINGS
Other objects, features and advantages of the invention
will be readily apparent from the following description of
respresentative embodiments thereof, taken in conjunction
with the accompany drawing, although variations and
modifications may be effected without departing from the
spirit and scope of the novel concepts embodied in the
disclosure, and in which:
FIG. 1 is a fragmentary elevational view of a bag
embodying the present invention;
FIG. 2 is an enlarged fragmental sectional
-3-
~;~68743
detail view taken substantially along the line II-II of
FIG. l;
FIG. 3 is a schematic illustration showing how
bag making material for the present invention may be
made;
FIG. ~ is an enlarged fragmentary sectional
detail view taken substantially along the line IV-IV in
FIG. 3;
FIG. 5 is a schematic illustration showing a
modified way of producing bag making material for the
present invention;
FIG. 6 is an enlarged fragmentary sectional
detail view taken substantially along the line VI-VI in
FIG. l;
FIG. 7 is a fragmentary sectional detail view
similar to FIG. 6, but showing the zipper in an
alternative interlocked enterengagement;
FIG, 8 is a schematic illustration of a manner
of extruding zipper strips in a mass production manner;
FIG. 9 is an enlarged sectional detail view of
a modified form of the zipper strip;
FIG. 10 is a fragmental, enlarged sectional
detail view showing another modified form of the zipper
strip;
FIG. 11 is a view similar to FIG 10, but
showing still another modified form of the zipper
strip;
8743
FIG. 12 is a fragmentary perspective view of
bag making material showing a still further
modification of the zipper strip;
FIG. 13 iS an enlarged sectional detail view
taken substantially along the line XIII-XIII in FIG.
12;
FIG. 14 iS a fragmentary perspective view of
ba~ making material, similar to FIG. 12, but showing a
modification thereof;
FIG. lS is an enlarged sectional detail view
taken substantially along the line XV-XV in FIG. 4;
FIG. 16 is an enlarged fragmentary sectional
detail view taken substantially along the line XVI-XVI
in FIG. 14;
FIG. 17 is a fragmentary perspective view of
bag making material, similar to FIG. 14, but showing
still another modification;
FIG. 18 is an enlarged sectional detail view
taken substantially along the line XVIII-XVIII in FIG.
17; and
FIG. 19 is an enlarged fragmentary sectional
detail view taken substantially along the line XIX-XIX
in FIG. 17.
Referring to FIG. 1, a bag 10 has confronting
wall panels 11 which may be made from any suitable
sheet material but in a popular form may comprise
plastic film such as polyethylene, polypropylene, or
~8743
the like, either in single thickness material or a
laminate where the desirable characteristics of
different plastic materials are desired, according to
conventional practice.
The panels 11 are connected together along
opposite side edges 12 and 13 and along a bottom end
14. At its upper end, the bag 10 has a top opening 15
best visualized in FIG. 6. The side edge 12 may be a
fold juncture while the side edge 13 and bottom end 14
lG may be heat seal seamed closed.
A reclosable zipper 17 is sandwiched between
the upper portions of the wall panels 11 and extends
lengthwise between the side edges 12 and 13. The
æipper 17 comprises a continuous length of extruded
profiled plastic strip having a plurality of spaced
parallel profile parts, in this instance comprising two
parts 18 and 19. The strip is folded upon itself to
provide confronting complementary portions 20, which
extend from a fold 21. One of the zipper portions 20
is attached to one of the wall panels 11 and the other
of the portions 20 is attached to the other of the wall
portions 11. Desirably the zipper strip fold 21 is
located in the folded side 12 of the bag 10. The
zipper profile parts 17 and 19 are releasibly
interengagable with one another for closing the top
opening 15.
In order to retain the folded zipper strip
74~
portions 20 against springing open at the fold 21, the
strip portions 20 are spot sealed together as shown at
21a; as visualized in FIGS. 1 and 2. Where the
material of the bag wall panels 11 is fusibly
compatible with ~he material of the zipper strips 17,
the portions of the wall panels contiguous to the fold
spot seal 21a may be fusibly sealed to the spot seal
21a. In addition, the opposite, originally free ends
of the zipper strip portions 20 are desirably spot
sealed together as shown at 22. The spot seal 22 may
extend inwardly from the heat sealed closure seam 13.
In an efficient arrangement, the zipper strip
17 comprises a flanged base 23 secured either by fusion
or adhesively to the bag wall panels 11. From one face
of the base 23 the profile parts 18 and 19 project
integrally in spaced parallel relation. The profile
part 18 has a curved neck 24 topped by an arrow shaped
head 25. On the other hand, the profile part 19 has a
curved neck 27 and an arrow shaped head 28. In order
to facilitate separable interlocking interengagement of
the profile parts of the folded zipper strip, the necks
24 and 27 are formed on approximately a common radius
and are spaced apart sufficiently to provide a groove
29 receptive of one of the profile part heads 25 or 28
as the case may be. At their confronting sides, the
heads 25 and 28 are spaced apart a substance somewhat
greater than the thickness of the necks 24 and 27, but
1~8743
less than the overall width of either of the respective
heads 25 and 28. Thereby , the respective profile part
heads can engage within the groove 29 of the co~panion
folded zipper strip portion as shown in FIGS. 6 and
7. In FIG. 6 the profile part head 28 is engaged in
the groove 29 of one of the zipper strip portions 20
and the head 25 is enyaged in the gro~ve 29 ~f the
other zipper strip portion 20. As shown in FIG. 7,
just the reverse enterengagement of the heads within
the grooves prevails. In either event, the zipper is
thoroughly closed. Both in the closing manuever and in
the separating manuever, the necks 24 and 27 enable
resilient flexing of the profile parts for the heads 25
and 28 to pass one another.
In order to provide for thorough resistance to
opening of the zipper due to pressures within the bag
10, without inhibiting the opening of the bag by
opening manuever applied at the outside of the bag
opening 15, the zipper profile part 18 is constructed
stiffer than the part 19 by a somewhat greater mass in
at least the profile head 25, and desirably also in the
connecting neck 24. This stiffening of the profile rib
parts 18 also facilitates interengagement of the zipper
portions to assure that the profile part 18 of the
folded strip always engages with itself in mutually
resistive fashion relative to pressure from the inside
of the bag tending to separate the zipper.
8743
Desirably, the zipper base flange 23 extends
to both sides of the zipper profile parts, a flange
portion 30 which is relatively narrow extending toward
the inside of the bag. A flange portion 31 which may
be substantially wider extends outwardly toward the top
of the bag, and together with the upper portions of the
bag side walls 11 provides respective pull flanges
which project outwardly from the zipper 17 and
facilitate grasping to pull the æipper open when
desired. The zipper 17 is easily closed by applying
pressure inwardly on the side wall panels in line with
the zipper.
By having one of the flange portions 30 or 31,
and in this instance the flange portion 31, extending
to a substantial width beyond the profile parts 18 and
19, manipulation and attachment of the zipper strip 17
is facilitated. Another advantage of the wider flange
portion 31 is that it facilitates folding of the zipper
strip 17 upon itself because the web portion 31 allows
more readily for the shift in the profiles 18 and 19
when they are folded on each other, and the slipping of
the profiles into locking enterengagement.
In producing bag material, as indicated in
FIG. 3, a continuous ribbon of bag wall web W may be
provided. Across the width of the web W, and at
suitable bag length intervals therealong, the zipper
strips 17 are attached to the web in any suitable
~87~3
fashion, such as by heat sealing where that is feasible
or by means of adhesive, all according to known
techniques. Each of the zipper strips 17 may be
notched at 32 to facilitate folding of the zipper strip
when each bag section is separated from the ribbon W as
along a line 33 and then folded along the bag side edge
line 12.
The zipper strips 17 may be economically
produced in a mass production manner by extruding a
plurality of the strips in a tubular extrusion 34 (FIG.
8). For example, eight of the zipper strips 17 may be
produced in the one extrusion 34 and the extrusion
separated along longitudinal lines 35 to divide the
same into individual zipper strips 17.
Where it is preferred to produce the web and
the zipper profile as a one piece extrusion, the
arrangement shown in FIG. 5 may be employed wherein the
web ribbon W' has zipper 17' integrally extending
lengthwise therealong. The overall width of the web W'
will be the same as the desired length of the bags to
be made from the web. Then the web is divided into
sections as shown which are equivalent to twice the
width of the bags to be made therefrom, with each of
the bag sections being folded along the line 37
extending through a notch 32' in the zipper strip to
facilitate folding. Of course, if it is preferred to
supply ~he web W' with the zipper 17' separately
--10--
743
fabricated, that may be done, tha zipper 17' being either
secured by heat sealing or adhesively, as may be
preferred. The end result will be the same as the bag
sections dervied from the web W in FIG. 3, namely, each bag
material section will result in a bag such as the bag lO in
FIG. 1.
For larger size bags and which may be required to
handle large volume contents, a zipper 38 (FIG. 9) may be
provided having a plurality of spaced parallel profile parts
greater than two. For example, five profile parts 39 are
shown carried by a base panel strip 40. In this instance,
the profile part 39 along one edge of the base 40 has a nect
41 and an arrow shaped head 42 which is of greater mass than
necks 43 and arrow heads 44 of the remaining profile
parts. It will be appreciated that the zipper strip 38 is
adapted to be used in the same manner as the zipper strip
17. That is, the zipper strip 38 is secured to the bag body
web, and may be notched, and folded upon itself in the same
manner. The heavier or greater mass section profile apart
41, 42 will be located at the inside of the bag and thus
A~
lZ~i~743
resist opening of the zipper due to internal pressures
within the bag.
Where the zippers are prefabricated and then
assembled with prefabricated film or web, and one side of
the zipper in each instance is equipped to provide internal
bag pressure resistance as has been described, it is
important that the side of the zipper which is so equipped
be properly placed when attaching the zipper to the web.
Such proper placement, is visually determinable by ready
identification of the resistance equipped side of the
zipper, that is, the side which is provided by the heavier
section profile parts 24, 25 (Figs. 6 and 7) and 41, 42
(Fig. 9) as previously described herein.
In FIG. 10, there is shown another zipper 47
wherein a single strip is folded upon itself and secured to
opposite wall panels 48 of a bag. In this construction,
C~
37~3
which comprises four generally arrowshaped profiles on a
base panel strip 49, there is on the side which is at the
mouth end of the bag a side flange 50 which is of
substantial width, and not only provides together with the
contiguous portions of the bag walls 48 a substantial pull
flange, but also facilitates attachment of the components
and facilitates folding of the zipper on itself. The
three profiles 51 which are closest to the pull flange
50 have groove spaces 52 between them which are all
equal but somewhat wider than the width of the
arrowhead rib portions of the profiles. On the other
hand, a spacing groove 53 between a fourth, innermost
profile 54 and the adJ'acent profile 51 is marrower
than the groove spaces 52, but just wide enough to
accommodate the rib head of the profile 54. In this manner,
the lateral flanges of the rib head of the profile 54 will
in each instance oppose to a maximum extent the head flanges
of the profiles 51 and 54 alongside the groove space 53
A~
743
into which the opposite profile 54 is assembled when
closing the zipper 47 by interlocking the profiles. In
contrast, lesser rib head flange surface opposition
exists in the groove spaces 52. As a result, the
innermost profile 54 affords substantially greater
resistance to separation from separating forces which
may develop at the inside of the bag, as compared to
separating forces applied to the zipper 47 at the
outerside of the bag by manipulation of the pull
flanges 50.
In another arrangement as shown in FIG. 11, a
zipper 55 has opposite zipper strip bases 57 which are
secured to opposite wall panels 58 of a bag.
Substantially wider flange portions 59 along the outer
sides of the zipper strip bases 57 cooperate with the
mouth end portions of the bag wall panels 58, and
provide substantial pull flanges, as well as the
additional advantages of facilitating attachment of the
zipper to the wall panels and folding of the zipper
strip on itself. In this instance, there are four
generally arrowshaped zipper profiles on each base
strip 57, comprising three identical profiles 60
inwardly from the flange portions 59, and a fourth
generally arrowshaped profile 61 at the inner side of
each base strip 57. All of the profiles 60 and 61 of
the zipper 55 are, in this instance, equally spaced
from one another and define grooves 60a between the
743
profiles 60 and a respective groove 61a between each of the
profiles 61 and the adjacent profile 60. Greater resistance
to opening due to forces from within the bag is achieved by
tilting or biasing the arrowhead of each of the innermost
profiles 61 toward the adjacent profile 60, by curving necks
62 of the profiles 61 toward the adjcent profile 60.
Through this arrangement, when the profiles are interlocked,
a side flange 63 on the profile 61 in groove 61a interlocks
with an ad~acent side flange 64 of the nearest profile 60 to
close to a neck 65 of the profile 60. Thereby forces
interiorly of the bag tending to separate the zipper are
resisted by the interengagement of the side flanges 63 and
64. On the other hand. the normal interengagemsnt of the
opposing head side flanges of the profiles 60 permits easier
opening of the zipper at the mouth end of the bag as may be
effected by manipulation of the pull flanges 59.
Another advantage of the tilted relation of the
profile 61 relative to the other profiles is that is provides
visual differentiation, or recoqnition, of profile 61 from
especially the adjacent profile 60. Therefore, when assem-
bling the prefabricated zipper with prefabricated film or web,
it can be readily determined which side of the zipper is to be
placed in the position of internal bag pressure resistanceO
A zipper strip 67, as depicted in FIGS. 12 and 13,
is secured to and across the bag mouth end of bag panels 68
formed from a single sheet of bag material adapted to be folded
upon itself along a longitudinal line 69 to bring the panels
68 together in forming a bag. This fold line 69 intersects
the zipper strip 67 so that profiles 70 of the zipper
strip will interengage or separably interlock as shown in
FIG. 13. At the fold 69, as well as at the opposite
-15-
~,tj87~3
interlocked ends of the folded zipper strip 67, the
zipper strip may be secured together by spot heat
sealing, similarly as described at 21 and 22 in FIGS. 1
and 2.
Generally, like FIGS. 10 and 11, the zipper
strip 67 has four arrowshaped profiles 70 which, in
this instance, are of the same geometry and equally
spaced from one another and are located inwardly from a
flange portion 71 of substan'ial width of base panel
72.
To render the folded zipper 67 capable of
resisting opening from the inside of the bag to a
substantially greater extent relative to opening from
the outer or mouth end of the bag, at which the flange
portion 71 serves as part of pull flange structure 74
of the bag, only the flange portion 71 is attached to
pull flange end portions 75 of the bag wall panels
68. Thereby, the wall panels 68 are flexibly
divertible along hinges 77 relative to the zipper 67.
It will be observed that the hinges 77 are spaced from
the outermost of the profiles 70. As a result, the bag
walls 68 may balloon without placing any significant
opening force on the zipper 67. On the other hand, the
zipper 67 can be easily opened by manipulating the pull
flanges 74.
For greater resilient flexibility, the base 72
may be provided with indented grooves 78 extending
-16-
1~i874;~
longitudinally along the base 72 in alignment with the
respective neck portions of the arrowshaped profiles
70.
As shown in FIG. 14, bag making material
similar to that shown in FIG. 12 may comprise bag wall
sheet with material 79 of any preferred type suitable
for the intended purpose and adapted to be folded along
a longitudinal line 80 to provide bag wall panels 81
adapted to be folded upon themselves and sealed along
the joined longitudinal edges and then severed into bag
length sections from a continuous strip of the
material. Along the end of the sheet 79 to form the
top reclosable end of a bag, a zipper strip 82 is
secured. This zipper strip 82 is of a continuous
length and extends across the entire width of both of
the panels 81, and when the sheet 79 is folded along
the line 80, the zipper strip 82 is similarly folded
upon itself along that line which extends across the
zipper strip. In this instance, the zipper strip 82
comprises a base 83 carrying three generally
arrowshaped profiles 8~ extending therealong, and which
are interlockably separably interengagable when the
zipper strip is folded upon itself.
Attachment of the zipper strip 82 to the sheet
79 is in a manner to resist opening of the zipper from
the inside of the bag to a substantially greater extent
relative to opening from the outer or mouth end of the
3743
bag into which the material is to be formed. And for
this purpose, the entire face of the base 83 which
opposes one of the panels 81 may be secured as by heat
sealing or adhesive means 85 (as indicated by stippling
in FIG. 14). Such securement includes a pull flange
portion 87. On the other of the panels 81, only the
pull flange portion 87 of the zipper strip 82 is
secured to such panel by ~he securement means 85, the
remainder of the zipper base 83 remaining unattached as
shown in FIG. 16. In the finished bag, this affords
stress relief avoiding opening of the closed zipper due
to internal pressures within the bag.
The construction in FIG. 17 is similar to the
construction in FIG. 14, and therefore primed reference
numerals are applied in FIG. 17 to identify
substantially similar parts. As noted, a film or sheet
79' in a continuous ribbon or strip of desired width to
be formed into successive bag sections is arranged to
be divided longitudinally along a line 80' to provide
panels 81' to be folded onto themselves and then
secured together at their longitudinal edges. A zipper
strip 82' having a base 83' and generally arrowshaped
profiles 84' extends across the sheet 79' at the place
which will provide the top or reclosable end of a bag
when the material is folded upon itself, including the
strip 82' wherein the profiles 84' are releasably
interlockable. Along what will be the top of the bag,
-18-
j8743
the strip 82' has a pull flange extension 87' which is
secured by means 85' to the bag wall sections 81'. In
this instance, the zipper strip 82' has an inward
lateral flange extension 88 projecting in the opposite
direction from the flange 87'. The flange 88 may be
secured by means 89 such as heat sealing or adhesive,
to one of the panels81' but, as shown in FIGS. 17 and
18, remain unsecured to the other of the panels 81' as
shown in FIGS. 17 and 19. This serves to relieve the
closed zipper from internal pressures within the
ultimate bag which might tend to open the zipper from
the inside. It will be observed that except for the
securing means 85' and 89, the base portion of the
zipper strip 82', including the flange 88, remains
unattached to the sheet 79'.
It will be understood that variations and
modifications may be effected without departing from
the spirit and scope of the novel concepts of the
present invention.
--19--
