Note: Descriptions are shown in the official language in which they were submitted.
~,o796~7 ~,
SPECIFICATION
This invention relates to improvements in extruded
construction for bags, and is more particularly concerned with
a construction especially suitable for reclosable bags which are -
adapted to be initially hermetically sealed and which after being
opened are reclosable.
A wide variety of products from foodstuffs to hardwar~
and materials in liquid or granular form are desirably packaged
in flexible plastic bags which may or may not be transparent or
at least translucent. With certain types of packaged contents, it ;
is desirable to provide means preventing unauthorized access to
the contents or to prevent spillage. O~ten the contents must remain
hermetically sealed until used. With pourable contents, whether
liquid or particulate, it is often desirable to have the bags equipped
with pouring spout means. A type of bag which is especially
suitable for these purposes is disclosed in U.S. Patent 3,746,215.
However, the ~ags disclosed therein are constructed from a
plurality of separately formed parts secured together in a manner
that complicates and increases cost o~ manufacture because of
the particular multi-part fabrication and ~he necessary assembling
- and securing together of such parts. In particular in that patent
the gusset member is formed as a separate piece or pieces and
then heat sealed to the inner surface of the main container in-
wardly relative to the separable fastener profiles. That con-
struction is difficult and expensive to make.
Tubular extrusions for manufacture of bags are disclosed,
for exarnple, in U.S. ~atents Re. 29,331, Re. 2~,991 and 3,380,481.
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Although those patents disclose the integral extrusion of film
and of separable zipper type resiliently flexible fasteners, they
fail to have any provision for a flexible closure web area
inwardly from the flexible fastener profiles with pull flanges
extending outwardly relative to the fastener profiles, the closure
web area being adapted to serve, if desired, as sealing gusset
means which may also provide pouring spout means.
It is, accordingly, an important object of the present
invention to provide a new and improved extruded construction
for reclosable bags which comprises in a single one piece plastic
extrusion, a ~lexible, collapsibly foldable thin wall gusset web
area, a pair of pull flange portions and interlocking complementary
fastener profiles, and with which are joined bag side wàll panels
may be integrally extruded or separately formed and joined
thereto; and a method of making the same.
In various embodiments of the invention there is provided
a new and improved plastic extruded bag construction comprising
a unitary one-piece plastic extrusion including a thin-wall plastic
closure web area, and pull flange portions of substantial leng~
all in one piece in said extrusion together with said closure
web area and having lower proximal ends joined respectively
to opposite ends of said closure web area, said pull flange
portions arranged to extend upwardly at respectively opposite
sides of a bag mouth at the top of the bag; separable resiliently
flexible interlocking complementary fastener profiles integral in
one piece in said extrusion with said closure web area and said
pull flange portions adjacent to said proximal ends and arranged
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to be interlockingly separably coupled together and separated
by manipulation of said pull flange portions and flexing of said
closure web area, and a bag body having side wall panels with
- upper end parts thereof joined tO the extrusion adjacent to the
profiles whereby the closure web provides a closure across the
bag mouth inwardly from the fastener profiles and which closure
must be ruptured to gain access into the bag. The side wall
panels may be extruded integrally with the extrusion together with
the closure web area, the flange portions the fastener profiles, `
or the side wall panels may be separately formed and sealed to
a gusset formed by the collapsibly folded closure web area to the
flange portions, adjacent to the profiles. The profiles may be
extrusion molded on the pull flange portions or may be extrusion
molded on the gusset closely adjacent to the pull flange portions
or may, in effect, be extrusion molded to the pull flange portions ,
and the gusset where they join together.
The collapsibly folded gusset may be formed into a funnel
spout element for each bag or may serve simply as a hermetic
seal untilit is desired to open the associated bag which has been
formed by hermetically sealing as necessary along edges of the
side wall panels.
A method for making the various embodiments of the
invention comprises forming in an integral one piece plastic
extrusion a flexible collapsibly foldable thin wall closure web area
joined at its opposite ends to proximal ends of a pair of pu~l
flange portions of substantial length, and as part of the extrusion
forming separable resiliently ~lexible interlocking complementary
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fastener profiles adjacent to said proximal ends; collapsibly
fQlding the closure web area away frorn the flange portions and
the profiles, coupling the fastener profiles together, and
enveloping the collapsibly folded closure web area within bag
body side wall panels having end parts joined to ~he extrusion
adjacent to the profiles. The side wall panels may be extruded
integrally with the closure web area, the flange portions the
fastener profiles, or the side wall panels m~y be separately
formed and sealed to the collapsibly folded closure web area or
the flange portions adjacent to the profiles. The profiles may
be extrusion molded on the pull flange portions, or may be
extrusion molded on the gusset closely adjacent to the pull flange
portions or may, in effect, be extrusion molded to the pull flange
portions and the gusset where the they join together. Especially
where the profiles are on the pull flanges, the profiles are
efficiently cooled from both sides of the respective flange portions
following the extrusion.
ON THE DRAWINGS
Fig. 1 is a schematic illustration of a method of extruding,
and initial treatment of, an integral extruded construction for bags,
according to the present invention, in this instance comprising a
tubular extrusion.
Fig. 2 is an enlarged vertical detail view showing the
extrusion as formed in Fig. l, collapsed into a bag configuration.
Fig. 3 is a view similar to Fig. 2, but showing the lower
fold joint of the side wall panels sliced open.
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Fig. 4 is a view similar to Fig. 3 but showing the wall
panels folded back to expose the infolded gusset web area between
the profile-carrying, separating flanges.
Fig. 5 is a reduced scale fragmentary plan view taken
substantially in the plane of line V-V of Fig. 4.
Fig. 6 is a plan view similar to Fig. S, but showing how
the infolded gusset is formed into funnel spout shape.
Fig. 7 is a fragmental plan view similar to Pig. 6 but
showing the side walls folded back to original position and illustrates
steps in transverse sealing of the collapsed extrusîon construction
into individual bags.
Fig. 8 is an elevational view of a fully sealed bag.
Fig. 9 is an elevational view of the bag inverted and the
combination closure web or gusset and funnel spout extended for
pouring from the bag.
~ig. 10 is a s~-hematic illustration of ano~er method of
extruding, and initial treatment of, and integral extruded construction
for bags according to the present invention, in this instance com-
prising a substantially flat extrusion.
As illustrated in Fig. 1, an integral extrusion construction
lO for bags is adapted to be formed by extrusion of suitable
therrnoplastic material, utilizing any preferred extrusion process
and equipment which may conveniently be substantially according
to that disclosed in U.S. Patent Re. 26,991 irl which the extrudate
is forced from an extruder, schematically identified as 11, through
an annular die opening to provide a thin tubular film or web 12,
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the inside of the extruded tube being pressurized by means of
air to keep it from collapsing and to ~btain cross grain
orientation of the material. To any extent necessary the dis- ~
closure of said U.S. Patent Re. 26,991 is embodied herein by -
reference.
On the outside of the substantial diameter extruded tubular
plastic web 12 there are integrally formed in one piece with the
web 12 in the extrusion process two substantially circumferentially
spaced, longitudinally extending, angularly radially outwardly
projecting flange portions 13 of substantial length and which are
adapted ultimately to provide separating or opening or pull flanges
for bags to be fabricated from the extruded construction 10. In
the extruded tubular configuration, the flanges 13 have their
proximal ends integrally joined with the web 12 and are disposed
in generally diverging relation with a flexible, collapsibly ~oldable
closure web area 14 of the tubular web 12 between the flanges.
' In one practical form, the closure web area 14 comprises about
one third of the circumference of the tube to provide for an
infolded gusset of substantial length and two thirds of the cir-
cumference provides the wall panels of ~e body portions of bags
to be fabricated from the extrusion.
On their generally opposing faces, the flanges 13 are
provided with separable zipper type resilien~y flexible fastener
means comprising a male profile 15 integrally formed by extrusion
on one of the flanges 13 and a receptive complementary female
profile 17 integrally formed by extrusion on the other of the
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flanges 13. Desirably the profiles 15 and 17 are located in
adjacently spaced relation to the tubular web 12, with sub-
stantial width free portions of the flanges 13 extending out-
wardly beyond the profiles.
As extruded, the thin tubular web 12 is cooled to main-
tain its form. In order to cool the profiles 15 and 17 which
are necessarily of larger mass than that of the adjacent body of -
the web 12, means such as nozzles 18 are provided for impinging
from opposite sides of the flanges 13 onto the areas thereof
occupied by the respective profiles 15 and 17. Thus, one of the
nozzles 18 in each instance directs coolant ~luid, su~h as air,
selectively directly against the associated profile, and the other
of the nozzles 18 in each instance projects coolant fluid against
the associated flange 13 selectively in the area thereof to which
IS the base o~ the associated profile 15 or 17, as the case may be,
is integrally attached in the extrusion. There is sufficient residual
cooling e~fect from the coolant impinged against the profile areas -
of the flanges 13 to also effect cooling of the ilanges 13. The
dual cooling of the profiles 15 and 17 both by front-on impingement
of the coolant and back-or base-on impingement of the coolant -~
assures that the profiles will be cooled substantially uniformly with
the web 12 and the ~anges 13 without wrinkling of the flanges 13
where the profiles are connected thereto, and permits high speed
manufacture of the extruded construction 10.
Immediately after extrusion of the construction 10, the
web 12 is collapsed along a diameter extending through the
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longitudinal center of the web area 14, and the web area 14 is
folded inwardly substantially as a gusset along parallel fold lines
19 (Fig. 2) at coincident extrusion juncture with the flanges 13
which are thus brought into close proximity to one another, and
the profiles 15 and 17 are separably interlocked in fastener
relationship. The collapsed body Q~ the web 12 beyond the
junctures 19 provides wall panels 20 between which the folded web
area 14 extends partway toward a terminal fold line juncture 21
connecting the panels 20.
After folding, the terminal fold line juncture 21 is slit
open along its length as shown in Fig. 3, and the wall panels 20
are turned away from each other into clearance relation to the
infolded web area 14, substantially as shown in Figs. 4 and 5.
Thereby, the infolded web area 14 is exposed for further processing
as shown in Fig. 6, comprising the effecting of a fusion seal such
as by electronic welding or heat sealing along a generally zigzag
line in order to provide convergent edges 22 extending between
the fold terminal of the web area 14 and the junctures 1~. This
separates the folded web area 14 into generally triangular sealed
20 closure and funnel spout structure elements 23 which are of a base
width substantially equivalent to the width of bags to be fabricated
from the tubular structure. The portions of the folded web 14
outside of the seal edges 22 are separated and discarded as scrap. `
After the formation of the combination closure and funnel
25 spout elements 23, the wall panels 20 are returned to their
original positions with the elements 23 th~rebetween, as shown in
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Fig. 7. Then fusion seals 24 are formed along transverse
lines extending entirely across the folded construction 10.
Thereby the construction 10 is se~arated into individual con-
tainer or bag units 25, which are fully hermetically sealed at
one end by the funnel spout elements 23 and are open at their
opposite ends so that they can be filled with any desired contents.
After filling, the bag units 25 are fusion sealed along lines 27
(Fig. 8~ across the formerly open ends, whereby the contents
are hermetically sealed within the bags. By having the fastener
15, 17 closed during filling of the bags 25 through their open
ends, outward displacement of the sealed funnel pouring spout
element 23 by imposition of the contents weight will be prevented.
After the open ends of the bags 25 are sealed at 27, the contents
are fully protected and isolated from externally located foreign ~ ~-
IS elements, and are protected against unauthorized access. The
bags can be handled without spilling the contents, and packing and ;~
shipping is facilitated. If for any reason the fastener 15, 17 of -
any bag should separate due to pressures within the bag or for
any other reason, the contents will not spill out because the bag
will remain closed and sealed by virtue of its completely sealed
element 23 formed from ~he integral web area 14. The element `-
23 is of sufficient area so that it can absorb distortion of the bag
walls and pressures and ~orces such as may occur when a sub-
stantial number of filled bags are packed for shipment or storage
or the bags are roughly handled during packing or when unpacking.
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It will be appreciated that if contents are to be packaged
in the bags 25 which require a relatively large opening from the
bag for removal of the contents, the infolded web area 14 may
be left untreated to that it will extend entirely across the bag and
be sealed at its sides in the side seals 24 of the bag. In such a
case, however~ as no spout is necessary the depth of the fold
may be reduced, thereby increasing the space available inside the
bag for the contents to be placed inside of it. Where the contents
are of a type which it is desirable to pour under control~ed con-
dition from the bag container, the triangular shape of the sealing
funnel spout element 23 is desirable.
With either form of the closure web area structure, when
it is desired to remove contents, the flanges 13 are adapted to
be grasped and pulled apart to separate the fastener elements
15, 17 on the lower portions of the flanges to open the bag mouth
between the flanges. This will also spread the infolded web area
structure which may then be opened easily by means of a knife
or scissors which may be inserted into the infolded element while
it is still in the generally infolded position, or after inverting
20 the bag and permitting the contents load to push the element out
of the bag opening, the tip thereof may be cut off. An incision
in or separation OI only so much of the web area need be made as
necessary for the intended contents ~ischarging purpose. For
example, in the triangular element form 23 of the structure, after
25 it has been projected from the bag substantially as shown in
Fig. 9, the apex tip may be snipped off by a pair of scissors or
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merely torn off and the contents may then be controllaby released
by using the element as a funnel spout. After a desired quantity
of material is released from the bag, the funnel elements 23 may
be pushed back into the interior of the bag and the fastener 15,
17 closed in the normal manner. Inasmuch as the extended spout
element 23 intervenes be~veen the contents and the fastener 15,
17, the rib and groove elements of the fastener remaln free of the
contents which may be powder or other material. Therefore,
completely reliable resealing of the rib and groove fastener is
facilitated.
Instead of forming the integral extruded construction
initially with a tubular web as in Fig. 1, it may be more con-
venient or feasible to form an integral extruded construction 10'
(Fig. 10) from suitable thermoplastic material in an extruder
schematically identified as 11' having a die with a thin wide -
substantially straight die opening to provide a thin sheet, flat
flim or web 12'. On one side of the web 12' two substantially
spaced, longitudinally extending, angularl~ projecting flanges 13'
of substantial width are integrally formed in the extrusion process.
20 These flanges 13' are adapted ultimately to provide separating or
opening flanges for bags to be fabricated from the extruded
construction 10'. In the flat extruded configuration of the web 12',
the flanges 13' are disposed in generally parallel relation, with
a substantial width web area 14' between the flanges, and with the
web 12' extending a substantial distance on either side of the
flanges 13'. On their opposing faces, the flanges 13" are provided
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with separable zipper type resiliently flexible fastener means
comprising a male profile 15' integrally formed by extrusion
on one of the flanges 13', and a Eeceptive complementary female
profile 17' integrally formed by extrusion on the other of the
flanges 13'. A substantial length free portion of each of the
flanges 13' extends outwardly beyond the respective profiles.
As extruded, the web 12' is cooled to maintain its form.
In order to cool the profiles 15' and 17", nozzles 18' are provided,
similarly as in l~ig. 1, for impinging coolant from opposite sides
of the flanges 13' onto the areas thereof occupied by the respective
profiles 15' and 17'. One of the nozzles 18' in each instance
directs coolant fluid such as air, selectively directly against the
associated profile, and the other of the nozzles 18' in each instance
projects coolant fluid against the associated flange 13' selectively
in the area thereof to which the base of the associated profile
15' or 17', as the case may be, is integrally attached in the
extrusion.
Immediately after extrusion of the construction 10' it is
collapsed at least to the extent of folding the web area 14' along
20 a longitudinal center line in a direction away from the flanges 13'
to provide a gusset between parallel fold lines 19' as shown in
dot dash outline at juncture with the flanges 13'. At the same
time the flanges 13' are brought into close proximity to one another
and the profiles 15' and 17' separably interl¢cked in fastener
25 relationship. The web 12' at each side of the flanges 13' may be
irnmediately foldably collapsed to provide bag wall panels 20',
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and then swung back into clearance relation to the gusset folded
area 14', substantially in the same manner as described in
connection with Fig. 4. Of course if preferred the web panels
20' may be folded up toward one another alongside the fbnges
13' at the same time that the area 14' is folded in the opposite
direction. In any event, such folding back of the panels 20' ~`
need be effected only if it is desired to form the folded web area ;
14' into triangular spout elements similarly as the spout elements
23 in Fig. 6. Then with the panels 20' folded down alongside
the folded closure gusset area 14', the construction 10' may be
sealed along transverse lines similarly as depicted in Fig. 7 tO
provide individual bag units. After filling through open ends
opposite the closure provided by the ~olded closure gusset areas
14', the open ends are adapted to be sealed similarly as described ~-
l~ in connection with Fig. 8. Thereafter, the bag units may be
manipulated in the rnanner described in connection with Fig. 9.
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SUPPLEMENTARY DISCLOSURE
Fig. 11 is a schematic illustration of a method of
extruding an integral extruded construction for bags according to
the present invention wherein the fastener profiles are extruded
integrally with the gusset web area between the pull flange portions.
Fig. 12 is an enlarged vertical detail view showing the
extrusion as formed in Fig. 11, collapsed into a bag configuration.
Fig. 13 is a fragmental, schematic illustration of a further
method of extruding an integral construction for bags according
to the present invention and showing how the same is collapsed
to provide an infolded gusset and closure for reclosable bags.
Fig. 14 is an enlarged fragmental vertical detail view
showing a bag structure embodying the construction of Fig. 13.
Fig. 15 is a fragr,nentary transverse detail view of a
modification in a bag similar to the bag configuration in Fig. 14.
Fig. 16 is a schematic illustration of the method according
~o the present invention of integrally extruding a combination
gusset web, pull flange portions and fastener profiles in tubular
fashion.
Fig. 17 is a schematLc illustration of extruding a tubular
bag side wall construction.
Fig. 18 is an enlarged vertical view of a bag structure
which may embody ~e extrusion of Fig. 16; and
Fig. 19 is an enlarged vertical detail view showing a bag
structure embodying the extrusions of both of Figs. 17 and 18.
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Referring to Fig. 11, an integral extrusion construction
25 for bags is adapted to be formed by extrusion of suitable
thermoplastic material similarly as described in connection with
Fig. 1, extrudate being forced from an extruder, schematically
S identified as 27, through an annular die opening to provide a thin
tubular film or web 28. The inside of the extruded tube may be
pressurized by means of air to keep it from collapsing and to
obtain cross grain orientation of the material. Integrally formed -
in the extrusion process are two substantially circurnferentially
spaced longitudinally extending, angularly radially outwardly
projecting pull flange portions 29, each of which may have along
its distal end edge a reinforcing and digital grasp facilitating
bead 30. At their proximal ends, the flanges 29 are integral
with the web 28 and are disposed in generally diverging relation
at opposite sides of a flexible, collapsibly foldable gusset-forming
web area 31. In this instance, separable zipper-type resiliently
flexible fastener means are extruded integrally in one piece with
the gusset area 31, comprising a male profile 32 adjacent to
juncture of one of the flanges 29 with the web and a complementary
female profile 33 integrally extruded with the gusset area 31
adjacent to the other of the flanges 29. r
On completion of the extrusion, the web 28 is collapsed
along a diameter extending through the longitudinal center of the
gusset area 31, and the gusset area 31 folded inwardly substantially
as a gusset 34 (Fig. 12~ along parallel fold lines 35 at juncture
with the flanges 29. Thereby the flanges 29 are brought into
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close proximity to one another, and the profiles 32 and 33 are ~ -
separably interlocked in coupled fastener relationship. The
remainder of the col1apsed body of the web 28 collapsibly enfolds
the gusset 34 and provides bag body side wall panels 37. Both
the side wall panels 37 and the gusset 34 may be handled in
substantially the same manner as described for the finished ~ ~-
extrusion lO of Figs. 1-9 to provide filled reclosable bags. By ~-
locating the fastener 32, 33 inwardly from the juncture 35, less
strain on the separable fastener is imposed by unintentional ~ ~
I0 separating stresses on the flanges 29, although the fastener is ~ -
not quite as responsive to separation by pulling the flanges 29
apart when it is desired to open the bag, compared to the
arrangement in Fig. 2, for example. -
If preferred, the extruded construction may be made, as ;;
depicted in Fig. 13, by forming in an integral one piece extrusion
a flexible collapsibly foldable thin wall plastic gusset-forming web
area 38, a pair o~ pull flange portions comprising a pull flange
39 and a pull flange 40 of substantial width having proximal ends
integral with opposite sides of the gusset area 38, and separable ~ ~
resiliently flexible interlocking complementary fastener profiles ; ~ -
41 and 42 respectively adjacent to the proximal end of the flange ~
39 and the proximal end of the flange 40. In this instance the ~ -
profiles 41 and 42 are of the multiple hooked rib and groove
type and are arranged to be interlockingly separably coupled
25 together upon collapsibly folding the gusset web area 38, as shown
in dash outline, away from the flanges 39 and 40.
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To complete the bag configuration, the collapsibly folded
gusset area 38 is desirably enveloped in a generally telescoped
manner as a gusset 43 (Fig. 14) within a bag body having side
wall panels 44 with upper ends 45 joined in sealed relation to the ;
sides of the collapsibly folded gusset 43 adjacent to the profiles
41 and 42. As indicated in the dash outline in Fig. 14, the
side wall panels 44 may be formed as an initially flat thin wall
plastic web extrusion which is folded up to provide the bag body
side walls 44. If preferred, a tubular extxusion ma~ be spilt to
provide the bag body. At its lower end 46, the bag body extrusion
may be slit open similarly as described in connection with Fig. 3
for shaping the gusset 43 into pouring SpOUt formation, or merely
to fill the bag sections into which the structure is adapted to be
formed. On the other hand, the side wall panels 44 may be
provided as additional separate strip panels which after attachment
as by suitable plastic fusion bonding to the gusset 43 provide an
open bottom as indicated in dot dash outline, for bending back to
facilitate shaping of the gusset 43 into pouring spout configuration
and/or for filling bag sections of the completed structure.
In Fig. 15,the construction is similar to and may be made
by substantially the same method as the construction in Fig. 14.
Primed reference numerals represent the substantially equivalent
elements as in Fig. 14, except that the fastener profile 41' com-
:'
prises a double sided hooked male proiile and the fastener profile
42' comprises a complementary generally arrowhead profile.
Similarly as in Fig. 14, the ilanges 39' and 40' have their proximal
ends integral with the opposite sides of the gusset web area 38',
.
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the fastener proiiles 41' and 42' are integral with the extrusion
adjacent to the proximal ends of the flanges, and side wall
panels 44' have their upper ends 45' joined as by suitable plastic
bonding to the collapsibly folded gusset adjacent to the profiles
41' and 42'. If preferred, instead of extruding the blank for the
combined gusset, pull flange and fastener profile structure in
substantially the flat manner according to Fig. 13, the blank
may be extruded in tubular fashion, indicated by the dash line
connection of the tops of the flanges 39' and 40', and the tubular
l structure collapsed as shown to couple the fastener profiles 41'
and 42' and the pendulous gusset 38' for generally telescoped
disposition in the upper portion of the bag body.
On reference ~o Fig. 16, extrusion of a tubular combination
gusset forming area 50, pull flange forming area 51 and separable
respective male and female profiles 52 and 53 by means of an
extrusion die 54 is depicted. There is also depicted in Fig. 17
the forming of a tubular bag body extrusion 55 as by means of
an extrusion die 57. -~
In Fig. 18 assembly of the extrusions formed according
to Figs. 16 and 17 into a bag 58 is depicted. For this purpose,
the tubular extrusion of Fig. 16 is collapsed along a diameter
extending midway between the spaced fastener profiles 52 and 53
within the tubular extrusion to couple the profiles and extend the
gusset 52 as a pouch adapted to depend below the coupled profile
fastener while the pull flange area which is collapsed to extend
from the fastene3: in the opposite direction from the gusset 52
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provides respective pull flange portions 59 and 60. To envelop
the gusset in the mouth end portion of the bag 58, the tubular !,
bag body extrusion 55 may be split longitudinally so that the
gusset 50 projects into the bag body between side wall panels -
61 and 62. Edge portions 63 and 64 of the split tubular bag
extrusion are adapted to be sealingly secured as by fusion bonding
to the pull flange portions 59 and 60, respectively. This provides
a double thickness for the pull flanges. In the finished bag, if
preferred, the portion of the tubular gusset extrusion which in
the extrusion connects the flange portions 59 and 60 may be left
whole until it is desired to open the bag whereupon it may be ;
trimmed away as indicated in dash outline, although if preferred
that ~onnecting portion may be trimmed away when finishing the
bag. Of course, if it is preferred to make the bag body extrusion
' 15 55 and/or the combination gusset, fastener and pull flange extruded
from origi~ally substantially flat extruded material, the edge areas
63 and 64 of the bag body material may nevertheless be substantially
matched with and seal bonded to the flange portions 59 and 6~) and;
~ the resulting structure will be laminar stiffened double thickness
i', 20 pull flanges at the mouth of the bag 58.
To attain utmost security against unauthorized opening of
the bag and/or to maintain the unopened bag in a condition of utmost
security against leakage, a bag sLructure 65 as shown in Fig. 19
may be constructed utilizing the tubular extrusions of ~igs. 16 and
17. In this arrangement the combination gusset, fastener and
pull flange tubular construction is entirely enclosed within the
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mouth end portion of the collapsed bag body extrusion 55, with
the top end portion of the collapsed bag body extrusion 55
providing a closure cap 67 which may arch in spaced relation
over the closed end of the pull flange area 51 as shown in full
outline, or may be nested as shown in dash outline. Then, for
double sealing security, the upper end bag body wall portions 63
and 64 may be secured by suitable seal bonding such as fusion
bonding to the pull flange portions 59 and 60 above the coupled
fastener profiles 52 and 53, and the bag side wall panels 61 and
62 may also be attached by seal bonding to the sides of the
gusset 50 adjacent to the fastener profiles, as shown at 68. Of
course if circumstances warrant, the seal bonding 68 may be
omitted and attachment effected only between the upper end portions
63 and 64 and the pull flange portions 59 and 60. At the lower
IS ends of the bags 58 and 65, the collapsed body extrusion 55 may .
remain closed if the bags are to be filled by side filling technique.
On the other hand, where it is preferred to effect bottom~end
3 filling, the bag body extrusion 55 may be split open and sealed
closed after the filling operation. ~.
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