Note: Descriptions are shown in the official language in which they were submitted.
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ZIPPER-LOCK_BAG CHAIN _IT~I TEARABLE STRIP INTERCONNECTION
MEANS
DESCRIPTION
The present invention relates to improvements
in plastic bags and method of making plastic bags formed
in a continuous bag chain where adjacent bags are joined
by an interconnection and wherein the bags can be
separated either manually or by a machine operation
during an automatic filling procedure.
The bags which are involved are thin plastic
film bags which have sides and a bottom edge and at the
upper end have a reclosable zipper lock structure. The
zipper lock structure constitutes a set of interlocking
rib and groove profiles. The lock structure is closable
and the bag is closed by applying an opposed closure
pressure progressively along the length of the profile
elements. The lock structure and the bag is opened
when the profiles are separated by either drawing them
apart, such as by pulling flaps which extend above the
profiles laterally or by longitudinal movement of one
profile relative to another in such a manner that the
profiles snap apart. Reclosable bags of the type
described are disclosed, for example, in United States
Patent Nos. Re. 23,969, 3,338,284 and Re. 29,208.
In the manufacture of bags of the above type,
they are typically made by the plastic being
continuously extruded from a circular die to form an
endless profile tube. However, the bags can be made
from a folded flat film with interlocking profiles
adjacent either end with said profiles either attached
integrally or separately attached. In other words, the
profiles can be formed integrally with the material of
the bag or may be on strips which are then secured to
the bag material. In the tubular form, the mating
interlocking profiles are formed on the inner surface of
the tube. The profiles are joined when the plastic has
cooled sufficiently to eliminate distortion of the
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plastic. Subsequently, individual bags are formed by
cross-seals at spaced intervals to form a seam at each
of the side edges of each of the bags with the bags being
simultaneously cut from the tube at said seam.
In one commercially advantageous form, the bags
are manufactured and are stored to be sold and shipped
to the user who opens, fills and recloses the individual
bags. These bags may be stacked in boxes, but in one
preferred form, the bags are interconnected to each
other in strip or chain form with individual bags torn
off of the supply strip. This form of chain of bags is
advantageously utilized in automatic filling and
handling machines, and one arrangement for utilizing such
a chain of bags is disclosed in the copending
15 application, United States Patent No. 4,490,959, issued
1/1/85, where automatic machinery has been devised for
feeding, opening, and reclosing the reclosable bags.
Such mechanism utili~es a series of interconnected
bags drawing them along a travel path through work
stations of the machine. At one section of the machine,
the individual bags are removed from the supply chain
by being forcibly torn from the chain. Whether torn
from the chain or otherwise disconnected, a relatively
high speed production operation can occur by pulling the
chain of bags from a supply source, either a roll or a
box and having individual bags disconnected from the
chain as they are handled by the machine.
A significant feature of providing such a chain
of bags is that the formation of the chain or inter-
connection of the bag be done simply without interferingwith the manufacturing operation and without adversely
affectin~ the strength and appearance of the bag. Also,
whether the bags are forcibly torn from each other, or
the interconnecting means is broken or separated by
other arrangements as will be described herein, the
bags must he separated without damage to them, and also
separated rapidly and easily without slowing the high
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speed operation of the filling and closing machine.
It is accordingly an object of the present
invention to provide an improved method and bag chain
wherein individual bags can be supplied in a chain and
removed from the chain readily and easily and uniformly
without endangering the integrity of the bags.
A still further object of the invention is to
provide an improved bag chain structure wherein the bags
are reliably and simply attached to each other and are
easily and readily removed from the chain.
A further object of the invention is to provide
an improved bag chain structure wherein the ease of
separation of the bags can be controlled by the
structure.
A still further object of the invention is to
provide an improved structure for the attachment of bags
to each other to form a continuous chain wherein the
structure serves to accurately align the adjacent bags
to each other maintaining the interlocking rib and
groove elements and the top and bottom edges in
alignment.
A feature of one form of the invention is to
manufacture bags sequentially and provide a removable
strip along one or both edges wherein the strip can be
separated to sequentially release the bags such as by
tearing the strip from the edgeO
Another feature of the invention in
accordance with another form, is to provide a frangible
strip attached to the bags wherein the strip is
laminated to the bag material in a surface-to-surface
engagement so that it is reinforced over the area of
attachment but frangible in the area between the bags
thus permitting a strip of uniform weight to be used.
The strip can be formed of clear material which does not
interfere with the appearance of the bag or can be formed
of a decorative material which contributes to the
structure and function and appearance of the bags.
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Other objects, advantages and features as well
as equivalent methods and structures, will become more
apparent from the teaching of the principles of the
invention in connection with the disclosure of the
preferred embodiments in the specification, claims and
drawings, in which:
ON TEIE DRAWINGS
FIGVRE 1 is a perspective view showing a
section through one of a chain of bags constructed in
accordance with the principles of the present invention;
FIGURE 2 is a perspective view of another form
of bag chain;
FIGURE 3 is a fragmentary perspective view
of another form of chain structure;
15FIGURE 4 is a perspective view of a further
arrangement;
FIGURE 5 is a perspective view illustrating
removal of material for the use of the bag;
FIGURE 6 is a perspective view of another
form of bag arrangement;
FIGURE 7 is a perspective view of still
another form of bag arrangement; and
FIGURE 8 is a perspective view of a further
arrangement.
25Figure 1 illustrates a chain of bags with the
bags preerably formed of a thin polyethylene material
and attached to each other in a side~by-side relation-
ship. Bags are shown at 10 and 11 having heat sealed
side seams 14 and 15, and a cross section of the bag 9
is shown to illustrate sidewalls 12 and 13. The bottom
is closed along a heat sealed seam 16.
Adjacent the top of the bag on confronting
faces are pressure interlocking rib and groove elements
17 and 18. The rib and groove elements are separable
in using the bag by pulling apart flanges 23 and 24 at
the top of the bag. For purposes of interconnecting the
bags in a continuous chain, a strip 19 which is a
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continuation of the bag walls 12 and 13 below the bottom
seam 16, extends along the bottom of the bags and is
perforated below said seam by perforations 20. The side
seams 14 and 15 extend slightly beyond sealed seam 16
into the perforations 20 so that when the strip 19 is
torn along said perforations, the bags in the chain
become separated.
At the top is a similar strip 21 which is a
continuation of flange flap 24 and extends along the top
of the bags and is perforated by perforations 22.
As will be apparent from the drawings, and in
particular Fig. 1, each bag in the chain is fully
separated from each adjacent bag by a line of separation
which extends along and between the side seams 14 and 15
past the ends of the rib and groove elements 17, 18 which
end at the side seams. Above the rib and groove
elements, the separation extends through the pull-apart
flanges 23 and 2~ to the strip of material 21. Thereby,
when the strip of material 21 is removed as indicated by
the directional arrow, the bags will automatically
separate from one another at the pull-apart flanges 23
and 24 and the separated ends of the rib and groove
elements and throughout at least the major extent of the
separation below the rib and groove elements. In this
instance, such separation is all the way to the strip 19
which is concurrently separated from the bags as
indicated at the right side of Fig. 1 so that complete
release of the bags from one another is attained.
Thus, when utilizing the bags, the individual
connected bags after their rib and groove elements have
been pulled apart are filled and then the rib and groove
elements are pressed together. The filled bags are then
separated from the chain by tearing the strips 19 and 21
from the chain which release the individual bags from the
chain. Until the strips are torn off, the bags are
interconnected in a chain. It is also possible that the
user may wish to fill the individual bags after they
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have been separated from the chain. In that case the
bags will be released by tearing the strips off the
chain and each bag will be released to be taken indivi-
dually and filled when the strips are progressively
torn from the chain. The strips 19 and 21 are preferably
of material integral with the bag material.
In the arrangement of Figure 2, bags 25 and 26
are shown interconnected into a chain. The bags are
inverted and the rib and groove elements 27 are facing
downwardly. The bottom edges of the bag, 30 and 31 (at
the top in Fig. 2), remain unattached so that access to
the interior of the bag is afforded for a filling
machine. Along the outer surfaces of the bag adjacent
to the bottom edges 30 and 31 are ribs 32 and 33 which
may be employed by a bag filling machine to support the
bag. That is, the ribs have downwardly facing shoulders
so that they can slide in recesses on the bag machine.
A double strip 28 has lines of perforations
at 28a which may be torn off to separate the bags. An
additional frangible connection link between the bags
in the chain is shown at 34, but this may be omitted
in some chain constructions where the bags are connected
only by the double strip 28 each of which is a continua-
tion of the respective bag walls. The link 34 may be
formed by plastic softened by heat with the plastic
supplied from the ribs 32 and 33 at 34a and 34b. Whenthe strip 28 is torn off, flanges 29 remain for
separating the rib and groove elements 27.
It may be noted that the frangible links 34
are divided into heat sealed areas 34a and 34b by cuts
thereby reducing the size of the links 34 to a
predetermined width which gives them the strength
necessary to hold the bags in a chain, but the links 34
are breakable when the bags are pulled apart.
In machine handling of a bag chain such as
shown in Figure 2, the chain is pulled through a
machine, the individual bags are filled between the
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separated edges 30 and 31, and the edges then joined by
a heat seal. The individual completed filled bags are
separated by being forcibly pulled from the chain and by
tearing off the strip 28.
Figure 3 illustrates another form of bag chain
which may be utilized in a machine which has recesses
to support the bag chain. The bags 36 of Figure 3 have
a rib 38 along the top. The rib is carried on a flap 37
which is integral with the flange 36a, but with perfora-
tions 39 extending between the flange 36a and flap 37.
For filling the bag, the front flange 36c is pulled
outwardly to separate rib and groove elements 36b and
afford access to the bag. The rib and groove elements
are then pressed together to close the top. When the
top flap 37 is torn off the chain along the
perforations 39, individual bags are rem~ed from the
chain.
In Figure 4 bags 40 and 41 of the chain are
connected to each other by a tear strip 42 at the top and
optionally additionally by a fracturable link 43 at the
bottom of the bags~ The link 43 is formed by a heat seal
area which is reduced in width to afford the proper
strength for attachment, but permit tearing. The strip
42 at the top has a line of perforations 42a which can
be torn to free the individual bags.
In Figure 6, a chain of bags is formed with
the bags interconnected by strips or attachment links
laminated to the surface of the bag material. Adjacent
bags 56 and 57 are attached to each other by small
attachment strips 50 which are laminated to the surface
of flaps such as front flaps 47 and 48 and rear flaps
` 47a and 48a. The strips 50 may be attached to either
the front flaps 47 and 48 or the rear flaps 47a and 48a.
If the bags are formed of material such as polyethylene,
the links 50 may be formed of a small strip of poly-
ethylene heat laminated to the surface area above the
rib and groove profiles 49, and may be of a material
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lighter in weight than the bag material for facilitating
tearing. Instead of being heat sealed, the links 50
may be adhesive backed. After the bags have been filled
through the top and the ribs and grooves rejoined, a
longitudinal pull is exerted on the end bag, and the link
50 connecting it to the next succeeding bag will break.
The strip 50, while being lightweight and frangible
lends some stiffness to the flaps to which it is
attached.
In the arrangement of Figures 5 and 7,
adjacent bags 51 and 52 having rib and groove profiles
53 on their inner confronting surfaces are attached to
each other by a continuous strip 54 which is doubled
over the top of the back flap 54a. The doubled strip
54 may be laminated to the bag material or attached
thereto by adhesive. The laminated strip 54 leaves free
a front flap 52a which can be pulled forward for opening
the bag for filling. The bags are then torn apart by
a longitudinal pull on the chain wherein the strip 54
breaks at the location between the bags. For this
purpose, it may be of a material weaker than the bag
material. If desired, a cut 55 may be placed in the
strip at the location between the bags with the cut
being of a predetermined length to leave an area of the
~5 strip sufficient to connect the bags but to permit easy
breakage.
As an alternate arrangement instead of the
strip 54 being torn, it may be peeled off the top of the
bag to separate individual bags such as when the bags are
fed through a machine.
While only one attachment structure may be
employed between bags, duplicate attachments may be used
both at the top and the bottom of the bag. A combination
of the different forms of links may be employed at the
top and bottom depending upon the circumstances of use.
When a continuous attached strip is employed,
such as that illustrated in Figures 1 and 2, this strip
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g
may be formed simultaneously with the manufacture of the
bag which will normally be made by a single operation
in being extruded from a die. Where interconnecting
means are attached to the bag, such as with the arrange-
ments shown in Figures 6 and 7, these may be attachedat the time the bags are cross-sealed.
Figure 8 illustrates a continuous chain of
bags interconnected by a continuous integral strip 59,
which is a continuation of the rear flange and rear bag
wall. Adjacent bags 55a and 56a are separated at their
side edges, but the upper ends of the bags are joined
by the strip 59 which is perforated from the rear
flange by perforations 58. For filling, the front flap
of the bags may be pulled forwardly, similarly to the
arrangement shown in Figure l, and when the bags are to
be separated, the strip 59 will be torn off to separate
the individual bags.
Thus, it will be seen that I have provided an
improved method and structure for bag chains which is
well suited for use in automatic bag handling machinery
such as where the machinery pulls the bag chain from a
supply source, opens, fills and recloses the bags.
While separation will normally occur in the automatic
machine, it may be done in a subsequent act by an
eventual user.
The preferred arrangements in accordance with
the principles of the invention have been shown and
described herein, but it will be understood that
equivalent structures and methods utilizing the
principles of the invention may be employed.
