U.S. patent application number 11/203703 was filed with the patent office on 2006-03-02 for transversely sealed container.
Invention is credited to Roger Bannister, Guy N. Davis.
Application Number | 20060045392 11/203703 |
Document ID | / |
Family ID | 35852098 |
Filed Date | 2006-03-02 |
United States Patent
Application |
20060045392 |
Kind Code |
A1 |
Bannister; Roger ; et
al. |
March 2, 2006 |
Transversely sealed container
Abstract
The disclosure is directed to a polyethylene or similar flexible
package having a maze vent to allow the escape of air from the
interior of the package filled with powdered or granular material.
The maze vent comprises an interior vented seal gap, a maze vent
channel, and a channel vent. The maze vent allows air to escape
during the filling process while maintaining the powdered or
granular material within the bag and preventing ingress of air,
moisture and other contaminants. The disclosure is directed to a
such a package by itself or as a liner to a multiple paper ply
satchel bottom bag, the poly liner being free within the innermost
ply except for attachment at the mouth of the bag. Further, the
satchel bottom bag of the present disclosure may contain a
reinforcing patch on the satchel bottom. Additionally, the
reinforcing patch may have an opener for easy opening of the
bag.
Inventors: |
Bannister; Roger; (Crossett,
AR) ; Davis; Guy N.; (Vancouver, WA) |
Correspondence
Address: |
BEMIS COMPANY, INC.
2200 BADGER AVENUE
OSHKOSH
WI
54904
US
|
Family ID: |
35852098 |
Appl. No.: |
11/203703 |
Filed: |
August 15, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60601944 |
Aug 16, 2004 |
|
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Current U.S.
Class: |
383/100 ;
383/102; 383/104; 383/109 |
Current CPC
Class: |
B65D 33/01 20130101;
B65D 31/04 20130101; B65D 31/08 20130101 |
Class at
Publication: |
383/100 ;
383/102; 383/104; 383/109 |
International
Class: |
B65D 33/01 20060101
B65D033/01; B65D 30/16 20060101 B65D030/16 |
Claims
1. A flexible polymeric package comprising: a seamless tubular body
having a first end, a second end, an inner surface and an outer
surface; a plurality of heat seals located proximate to said second
end permanently sealing said seamless tubular body to itself
creating a front panel and a rear panel; a heat sealable open mouth
at said first end, wherein a receptacle is defined by said inner
surface of said tubular body and said plurality of heat seals, said
receptacle being configured to receive a product introduced through
said open mouth and enclosing said product within said tubular
body, with said open mouth being heat sealable after introduction
of said product into said receptacle; said plurality of heat seals
comprising at least two spaced apart, heat seals oriented
transversely across said seamless tubular body proximate to said
second end; said at least two spaced apart heat seals comprising an
inboard heat seal positioned adjacent to said receptacle and an
outboard heat seal spaced apart from said inboard heat seal and
nearer said second end, wherein a channel is defined by said
inboard and outboard heat seals and said front and rear panels of
the seamless tubular body; and said inboard heat seal having a
discontinuity, wherein said front panel and said rear panel are
unattached to each other at the discontinuity allowing
communication between said receptacle and said channel through the
discontinuity.
2. The flexible polymeric package of claim 1 further comprising a
vent in said channel, wherein said vent allows communication
between said channel and an environment outside of the package.
3. The flexible polymeric package of claim 2 wherein said vent
comprises one or more perforations in the tubular body within the
channel.
4. The flexible polymeric package of claim 2 wherein said vent
comprises a plurality of perforations in the tubular body within
the channel.
5. The flexible polymeric package of claim 2 wherein said vent
comprises a plurality of perforations in at least one of said front
panel and said rear panel of the tubular body within said
channel.
6. The flexible polymeric package of claim 5 wherein both of said
front panel and said rear panel contain perforations within the
channel.
7. The flexible polymeric package of claim 2 wherein said vent
comprises a discontinuity in said outboard heat seal; said
discontinuity allowing communication between said channel and said
environment by way of a space between said front and said rear
panel to said second end.
8. The flexible polymeric package of claim 2 wherein said
discontinuity in said inboard heat seal is located proximate to one
end of said channel and said vent is located proximate to a second
opposite end of said channel, whereby communication between the
receptacle of said package and said environment takes place by way
of the substantial length of the channel.
9. The flexible polymeric package of claim 2 further comprising an
intermediate heat seal located between said inboard and said
outboard heat seal, wherein said intermediate heat seal contains
one or more discontinuities and creating a tortuous path between
said receptacle and said environment.
10. The flexible polymeric package of claim 2 further comprising
one or more maze blocks within said channel, wherein a maze block
comprises a heat seal substantially perpendicular to one of said
inboard and outboard heat seals.
11. The flexible polymeric package of claim 10 further comprising a
plurality of maze blocks perpendicular and connecting to said
inboard and said outboard heat seals.
12. The flexible polymeric package of claim 11 wherein said
connection of the maze blocks to said inboard heat seal and said
outboard heat seal alternates between the inboard and outboard heat
seal creating a tortuous path between said receptacle and said
environment.
13. The flexible polymeric package of claim 1 comprising: an
inboard heat seal positioned adjacent to said receptacle and having
a discontinuity proximate to one end; an outboard heat seal spaced
apart from said inboard heat seal nearer said second end, said
inboard and outboard heat seals being substantially parallel to
each other and oriented transversely across said seamless tubular
body proximate to said second end; a channel defined by said
inboard and outboard heat seals and said front and rear panels of
the tubular body; and a vent in said channel located opposite of
said discontinuity in said inboard heat seal, wherein a flow path
is defined from said receptacle, through said discontinuity,
through said channel, and out of said vent to an environment
outside said package, said flow path being designed to allow
passage of gaseous material out of said package and preventing
passage of product out of said package while preventing ingress of
moisture and other contaminants.
14. The flexible polymeric package of claim 13 wherein said vent
comprises a plurality of substantially aligned perforations in said
front panel and said rear panel within the channel.
15. A multiple ply paper bag with a polymeric liner comprising: at
least two paper plies being laterally offset, each being adhesively
bonded along a seam thereof forming a tube, and at least two of
said paper plies being stepped relative to each other in a
direction longitudinal of the bag, said tube having an open end and
a closed end; a seamless inner plastic liner being attached to an
innermost of said paper plies at said open end of the bag and
having a width less than one half the perimeter of the innermost
paper ply, said plastic liner having a plurality of heat seals at
the closed end of said bag for sealing said plastic liner to itself
and thereby form a plastic pouch having an interior and an exterior
defined by a front panel and a rear panel, and said plastic liner
further comprising a heat sealable mouth at said open end of the
bag; said plurality of heat seals comprising at least two spaced
apart heat seals oriented transverse to the long axis of the bag,
said heat seals having an inboard heat seal positioned adjacent to
the interior of the pouch and an outboard hear seal positioned
proximate to the bottom of the pouch, said inboard and outboard
heat seals defining a channel between said front panel and said
rear panel; said inboard heat seal containing a discontinuity,
wherein said front panel and said rear panel are unattached to each
other at the discontinuity allowing communication between the
interior of the pouch and the channel; and said closed end of said
bag having a satchel bottom capable of forming a rectangular bottom
of the bag when filled, said satchel bottom being formed by folds
of said paper plies being folded about three fold lines, one fold
line being a generally central transverse main fold along the
bottom of the bag and the other two being parallel secondary fold
lines equidistant from the main fold line, said innermost paper
plies being non-slitted and at least one other paper ply being
slitted, said folded paper ply having means to form geometric zones
of adhesion, an adhesive on said zones for securing said folded
paper plies together, said inner plastic liner being detachably and
non-adhesively retained at said satchel bottom, and the plastic
pouch being folded about said main fold line and one of said two
secondary fold lines.
16. The bag of claim 15 wherein said pouch contains a vent within
said channel creating a flow path from the pouch interior through
the discontinuity in the inboard heat seal, through the channel,
and through the vent to the exterior of the pouch.
17. The bag of claim 16 wherein said discontinuity in said inboard
heat seal is located proximate to one of the lateral sides of the
pouch and said vent is located proximate to an opposite lateral
side of the pouch.
18. The bag of claim 16 wherein said vent comprises one or more
perforations in at least one of said front panel and said rear
panel within the channel.
19. The bag of claim 17 wherein said vent comprises a plurality of
perforations in said front panel and said rear panel within the
channel.
20. The bag of claim 18 wherein said vent is comprised of 2 to 10
perforations.
21. The bag of claim 18 further comprising one or more maze blocks
within said channel, wherein a maze block comprises a heat seal
substantially perpendicular to one of said inboard and outboard
heat seals.
22. The bag of claim 21 further comprising a plurality of maze
blocks perpendicular and connecting to said inboard and said
outboard heat seals.
23. The bag of claim 22 wherein said connection of the maze blocks
to said inboard heat seal and said outboard heat seal alternates
between the inboard and outboard heat seal creating a tortuous path
between said interior and exterior of the pouch.
24. The bag of claim 17 further comprising a reinforcing patch
affixed to the outside of said satchel bottom over the folds of the
outer paper ply.
25. The bag of claim 24 wherein said reinforcing patch comprises at
least one ply of kraft paper adhesively affixed to the outside of
the satchel bottom.
26. The bag of claim 24 further comprising an easy-open apparatus,
said easy-open apparatus comprising an opener strip located within
the folds of the satchel bottom extending transversely outward from
the folds of the satchel bottom to cooperate with said reinforcing
patch, said reinforcing patch having a cuff defined by a pair of
spaced apart substantially parallel slits at one edge of the patch,
said opener strip attached to said cuff allowing a user to pull
said cuff and opener strip thereby tearing said patch and paper
plies of said underlying satchel bottom folds allowing the user to
open the satchel bottom to access the plastic liner.
27. The bag of claim 26 wherein said opener strip is made of
plastic.
28. A multiple ply paper bag with a polymeric liner comprising: at
least two paper plies being laterally offset, each being adhesively
bonded along a seam thereof forming a tube, and at least two of
said paper plies being stepped relative to each other in a
direction longitudinal of the bag, said tube having an open end and
a closed end; a seamless inner plastic liner being attached to an
innermost of said paper plies at said open end of the bag and
having a width less than one half the perimeter of the innermost
paper ply, said plastic liner further comprising a plurality of
heat seals at the closed end of said bag for sealing said plastic
liner to itself and thereby form a plastic pouch having an interior
and an exterior defined by a front panel and a rear panel, and said
plastic liner further comprising a heat sealable mouth at said open
end of the bag; said plurality of heat seals further comprising an
inboard heat seal located adjacent to the interior of said pouch
having a discontinuity in said inboard heat seal proximate to a
first lateral side edge of the pouch, and an outboard heat seal
spaced apart and substantially parallel to the inboard seal; a
channel located between said inboard and outboard heat seals and
defined by said front and rear panels; a vent in said channel
comprising a plurality of perforations in at least one of said
front panel and rear panel within the channel, said vent located
proximate to a second lateral side edge opposite that of said first
lateral side edge, wherein gaseous contents of said pouch interior
is allowed to flow through the discontinuity of the inboard heat
seal, through the channel, and out the vent to the exterior of the
pouch while restricting flow of product out of the pouch and
restricting flow of moisture and other contaminants into the pouch;
said closed end of said bag having a satchel bottom capable of
forming a rectangular bottom of the bag when filled, said satchel
bottom being formed by folds of said paper plies being folded about
three fold lines, one fold line being a generally central
transverse main fold along the bottom of the bag and the other two
being parallel secondary fold lines equidistant from the main fold
line, said innermost paper plies being non-slitted and at least one
other paper ply being slitted, said folded paper ply having means
to form geometric zones of adhesion, an adhesive on said zones for
securing said folded paper plies together, said inner plastic liner
being detachably and non-adhesively retained at said satchel
bottom, and the plastic pouch being folded about said main fold
line and one of said two secondary fold lines a reinforcing patch
adhesively affixed to the outer paper ply wherein said reinforcing
patch comprises at least one ply of kraft paper.
29. The bag of claim 28 further comprising an easy-open apparatus,
said easy-open apparatus comprising an opener strip located within
the folds of the satchel bottom extending transversely outward from
the folds of the satchel bottom to cooperate with said reinforcing
patch, said reinforcing patch having a cuff defined by a pair of
spaced apart substantially parallel slits at one edge of the patch,
said opener strip attached to said cuff allowing a user to pull
said cuff and opener strip thereby tearing said patch and paper
plies of said underlying satchel bottom folds allowing the user to
open the satchel bottom to access the plastic liner.
30. A method of forming a multiple ply paper bag with a polymeric
liner comprising the steps of: extruding a seamless polymeric tube;
cutting said polymeric tube to a desired length and thereby
defining a longitudinal axis, said polymeric tube having an
interior surface, an exterior surface, a first end and a second
end; sealing the second end of said polymeric tube with a plurality
of heat seals oriented transverse to said longitudinal axis, said
plurality of heat seals and said interior surface thereby defining
a receptacle configured to receive a product, said plurality of
heat seals having at least an inboard heat seal located adjacent
said receptacle and an outboard heat seal spaced apart from said
inboard seal, wherein a channel is defined between said inboard
heat seal and said outboard heat seal and a front panel and a rear
panel, and wherein said inboard heat seal contains a discontinuity
such that said receptacle is in communication with said channel
through the discontinuity; providing a plurality of offset paper
plies, said paper plies comprising at least an outermost paper ply
and an innermost paper ply, said paper plies being folded such that
each of said plies is bonded to itself forming a multi-ply paper
tube with a seam for each ply, said seams being laterally offset
thereby spacing seams for each layer about the bag, said tube
having a first end and a second end; bonding said first end of said
polymeric tube to said first end of the innermost ply of said
multi-ply paper tube; folding opposing corners at said second end
of said multi-ply paper tube inward creating a pair of diagonal
fold lines, each diagonal fold line extending from a lateral side
edge of said multi-ply paper tube and defining a front flap and a
rear flap, whereby said polymeric tube is folded within said rear
flap folds and is freely and non-attachably retained; applying
adhesive to said front and rear flaps and folding said front and
rear to close said second end of said multi-ply paper tube thereby
forming a satchel bottom.
31. The method of forming a multiple ply paper bag with a polymeric
liner of claim 30 further comprising the step of: providing a vent
in said channel thereby creating a flow path whereby gaseous
material may pass from said receptacle through said discontinuity
in said inboard heat seal, pass through said channel through said
vent to an environment outside said polymeric liner.
32. The method of forming a multiple ply paper bag with a polymeric
liner of claim 31 further comprising the step of: perforating at
least one of said front panel and said rear panel of said channel
thereby forming a vent.
33. The method of forming a multiple ply paper bag with a polymeric
liner of claim 31 further comprising the step of: perforating both
said front panel and said rear panel of said channel thereby
forming a vent.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C.
.sctn.119(e) from U.S. Provisional Patent Application No.
60/601,944, filed on Aug. 16, 2004.
BACKGROUND OF THE DISCLOSURE
[0002] The present disclosure generally relates to an improved
plastic bag for use by itself or for use as a liner in conjunction
with a bag having multiple paper ply construction.
[0003] More specifically, the disclosure is directed to a seamless
tubular plastic liner for a multilayer satchel bottom type bag.
Such bags are known in the art, an example being disclosed in U.S.
Pat. No. 5,553,943 which is herein incorporated by reference.
Satchel bottom bags are formed by folding a plurality of layers of
kraft paper into a tube. The layers are arranged in stepped
configuration for adhesive bonding. A plastic liner or pouch is
inserted into the tube and secured by adhesive to the top, or the
mouth end of the tube.
[0004] Plastic lined multilayer paper bags are used to package bulk
granular or powdered products such as flour, corn meal, sugar,
powdered milk, and similar commodities as well as other powdered or
granular materials. The plastic liner may be either an additional
plastic ply bonded to the inner most paper ply, or a free-floating
plastic bag-within-a-bag as described herein.
[0005] Plastic bags made of polyethylene or other polymeric
materials are common packaging containers for a variety of products
and commodities. Such bags may be used either by themselves or as
liners for paper bags. The manufacturer of the bags seals one end
of the bag (called the "manufacturer end" or "plant end") which
forms the bottom seal of the bag when the bag is in use. The other
end (called the "customer end") is left open for the purchaser of
the bag to fill with its product and close and seal. The customer
end forms the top end of the bag through which material is
introduced into the interior of the bag.
[0006] When a polyethylene bag is filled with powdered or granular
material and sealed, air or other gases may become trapped in the
bag. This can create air pockets in the bag, which if not allowed
to escape, can result in problems when the bags are stacked for
shipment. For example, trapped air prevents the bag from conforming
to the powdered or granular contents creating air pockets. As bags
are placed on top of each other, such as for shipment on pallets,
the air bubbles make the stack of bags unstable and prone to
tipping, thus limiting the number of bags that can be stacked for
shipping. Also, as additional bags are placed on top of the bag
containing the trapped air, the air pockets are compressed due to
the additional weight, increasing the pressure inside the bag. If
enough weight is placed on the bag with the trapped air, the
increased air pressure may rupture the bag, resulting in spillage
of the contents. Therefore venting the air from the bag facilitates
stacking of bags for shipment and reduces the risk of bag
rupture.
[0007] Alternatively, venting of the plastic bag may not be
desirable in all situations, particularly when the contents are
toxic or hazardous, such as various types of chemicals. In this
situation, reinforcement of the seals is required to minimize the
possibility of rupture during transportation and handling.
[0008] More particularly, the present disclosure relates to a
seamless polyethylene, or similar polymer material bag, that has a
maze vent allowing air to escape after the bag has been sealed
while inhibiting the ingress of air, moisture and other
contaminants. Such vents are known in the art and typically consist
of one or more heat seals having a gap. The heat seals bond the
front and rear walls of the bag together. For example, U.S. Pat.
No. 6,491,433 teaches three heat seals, each with a gap being
offset from the gap in the adjacent seal or seals.
[0009] One method of manufacturing a vented seal bag is typically
accomplished by folding a sheet of polyethylene or similar material
into a tube. When the sheet is folded, overlapping edges form a
longitudinal seam in what is typically the back of the bag. The
overlapping edges are then sealed with a plurality of interrupted
heat seals. The interruptions in the heat seals are offset from the
interruption in adjacent heat seal or seals, forming a tortuous
path from the interior of the bag to the exterior, allowing trapped
air to be expelled. See U.S. Pat. No. 6,170,985.
[0010] These longitudinal seams are prone to failure, causing
leakage and contamination of the material contained within the
bag.
[0011] The present state of the art uses a flat film that is folded
to create bags with seams along the longitudinal axis of the bag
that incorporate a vent. These seams are prone to failure,
resulting in spilled product and associated wasted expense.
SUMMARY OF THE DISCLOSURE
[0012] This disclosure may be described as a novel and improved
plastic liner and multilayer paper satchel bottom bag incorporating
such a liner. The plastic (or "poly") liner may be used by itself
as an independent package, or may be incorporated as part of a
bag-within-a-bag. The poly liner is placed within a multilayer
paper satchel bottom bag for added strength and protection.
[0013] The poly liner is formed from a seamless tube of
polyethylene or similar polymer material folded flat forming a
front panel and a rear panel. A plurality of heat seals are made
across the bottom of the plastic tube transverse to the direction
of the bag. In one embodiment, a first solid heat seal and a second
interrupted heat seal are created across the bottom or satchel end
of the bag, sealing the bottom of the liner and forming a vent
channel between the heat seals. The interruption in the second heat
seal forms the vented seal gap. The vented seal gap is in
communication with the interior space of the bag. Next, one or both
of the front and rear panels of the liner are perforated within the
vent channel between the heat seals with a plurality of perforation
holes forming the exterior vent.
[0014] When the bag has been filled and sealed, an increase in
pressure within the bag will cause the front and rear panels of the
vent channel to separate allowing air to pass through the vented
seal gap, through the vent channel, and to be exhausted through the
exterior vent. When pressure has been reduced through venting, the
front and rear panels of the vent channel collapse against each
other, closing off the passage to the exterior of the bag and thus
sealing the bag against entry of moisture or other contaminants
from the outside.
[0015] In alternative embodiments, maze blocks may be formed within
the maze vent channel, substantially perpendicular to and in
communication with one or more of the transverse heat seals. The
maze blocks function to form a tortuous path through the vent
channel trapping powdered or granular product that may enter the
vent channel. Product is retained in the vent channel preventing
clogging of the exterior vent and/or leakage of product.
[0016] A machine known in the art, a W&H Rotaliner, is modified
to manufacture bags having the maze vent described herein. The
typical Rotaliner has a drum with a sealing bar having a sealing
surface. The sealing bar is modified by machining a gap in the
sealing surface corresponding to the second heat seal to create an
interruption in the second heat seal forming the vented seal gap.
If a bag is to be manufactured having maze blocks, weld beads are
created on the Rotaliner sealing bar in communication with and
substantially perpendicular to either the first or second heat seal
and machined.
[0017] Under certain circumstances, venting of the plastic liner
may not be desirable. It is, therefore, necessary to reinforce the
bottom heat seal to prevent rupture. Multiple solid heat seals are
provided at the bottom of the liner, instead of one interrupted
heat seal and one solid heat seal.
[0018] In one embodiment of this disclosure, it is envisioned that
a plastic liner of the type described herein is used in conjunction
with a satchel bottom bag constructed of a plurality of paper
layers or plies, such as kraft paper or high performance paper as
is generally known in the art. A plurality of paper plies are
folded into a tube wherein a plastic liner is inserted into the
tube and secured by adhesive to the innermost ply near the top or
mouth end.
[0019] The plastic liner is heat sealed at its bottom, or satchel
end, before insertion into the paper tube. The plastic liner is
also temporarily secured by adhesive to the inner paper ply of the
back wall of the bag. This is to secure the liner during the
satchel folding process.
[0020] The paper plies are folded to form a flat satchel bottom.
After bulk product is introduced into the bag, the mouth of the
plastic liner may be heat sealed closed. The paper plies at the
mouth end have a stepped configuration for adhesive bonding. The
paper plies are folded over and secured by adhesive, thus enclosing
the plastic liner and its contents.
[0021] The satchel end of the plastic liner is folded within but
not adhesively secured to the folds of the plies of the satchel
end. The liner is thus secured and held flat during transport of
the bag. As the bag is unfolded for filling, the plastic liner is
released from the folds of the satchel end and is a free-floating
bag-within-a-bag secured only at the top to the innermost paper
ply.
[0022] In another embodiment of the present disclosure, a patch is
provided on the outside of the folded satchel bottom. The patch may
be made of kraft paper or other suitable material and may be of one
or more layers and is adhesively affixed to the outside of the
satchel bottom. The patch provides additional reinforcement to the
satchel bottom.
[0023] In yet another embodiment, it may be desirable to provide an
easy opening bottom to the bag of the present disclosure. In this
embodiment, no adhesive is applied to the flaps of the satchel
bottom. A patch is adhesively applied to the outside of the satchel
bottom. An opener strip is provided between the patch and the flaps
of the satchel bottom. The opener strip terminates at a cuff area
at one side of the patch. A pair of slits are provided in the patch
on either side of the opener strip to form the cuff. The opener
strip may be formed of plastic, string, or other strong flexible
material. A user grips the cuff pulling away from the satchel
bottom. As the user pulls the cuff, the opener strip tears the
patch exposing the satchel flaps which are easily opened because
there is no adhesive securing them in place.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a view of a poly bag having a maze vent of the
present disclosure;
[0025] FIG. 2 is a view of a poly bag having another embodiment of
a maze vent of the present disclosure with maze blocks
perpendicular to the heat seals;
[0026] FIG. 3 is a view of a poly bag of the present disclosure
having a double bottom seal;
[0027] FIG. 4a is an alternate configuration for the maze vent of
the present disclosure;
[0028] FIG. 4b is another alternate configuration for the maze vent
of the present disclosure;
[0029] FIG. 4c is another alternate configuration for the maze vent
of the present disclosure;
[0030] FIG. 4d is another alternate configuration for the maze vent
of the present disclosure;
[0031] FIG. 4e is another alternate configuration for the maze vent
of the present disclosure;
[0032] FIG. 4f is another alternate configuration for the maze vent
of the present disclosure;
[0033] FIG. 4g is another alternate configuration for the maze vent
of the present disclosure;
[0034] FIG. 4h is another alternate configuration for the maze vent
of the present disclosure;
[0035] FIG. 4i is another alternate configuration for the maze vent
of the present disclosure;
[0036] FIG. 4j is another alternate configuration for the maze vent
of the present disclosure;
[0037] FIG. 4k is another alternate configuration for the maze vent
of the present disclosure;
[0038] FIG. 5 is a perspective view of the multi-ply plastic lined
bag with satchel bottom, partially broken away, and having a pinch
closure-type open top ready to be filled by a user with a commodity
or the like;
[0039] FIG. 6 is a front elevation view of a multi-layer bag blank
showing a main fold line and slits for forming a satchel
bottom;
[0040] FIG. 7 is a front elevation view of a tube blank with the
multiple paper plies at one side of the being folded upwardly
around the main score line to thereby define upper and lower paper
flaps and four diagonal bend lines in the paper ply flaps, both
above and below the main score line, and foldably holding at the
upper flap the plastic liner;
[0041] FIG. 8 is a detailed view of the folds of the satchel
bottom;
[0042] FIG. 9 is a detailed view of the folds of the satchel bottom
of a bag having an easy opening feature;
[0043] FIG. 10 is a detailed view of the completed satchel bottom
with reinforcing patch.
DETAILED DESCRIPTION
[0044] While the present disclosure will be described fully
hereinafter with reference to the accompanying drawings in which a
particular embodiment is shown, it is understood at the outset that
persons skilled in the art may modify the disclosure herein
described while still achieving the desired result of this
disclosure. Accordingly, the description which follows is to be
understood as a broad informative disclosure directed to persons
skilled in the appropriate arts and not as limitations of the
present disclosure.
[0045] FIG. 1 depicts the arrangement of an embodiment of the
present disclosure. A poly bag 10 is formed from a seamless tube of
polyethylene or similar polymer material creating an interior and
exterior. The tube is folded upon itself forming a first edge fold
12 and a second edge fold 14 and a front wall and a rear wall. When
the seamless tube is cut to the desired size, it will have two
ends. The first end 16, called the manufacturer end or the plant
end, is typically the bottom of the bag. The second end 18, called
the customer end because the bag purchaser seals this end after it
fills the bag with product, is left unsealed and is typically the
top of the bag. Located at the bottom end of the bag are at least
two heat seals, the first 20, a solid bottom seal, located nearer
the manufacturer end, closes the bottom of the bag. The second 22,
an interrupted seal, is located above the first heat seal 20 and is
in contact with the interior space of the bag. The second heat seal
22 is interrupted by a vented seal gap 24. The solid bottom seal 20
and the interrupted seal 22 are substantially parallel to each
other and define the vent channel 26 as the space between them.
Finally, there is an exterior vent 28 to allow the air to pass from
the vent channel 26 to the exterior of the bag. In the embodiment
shown in FIG. 1, the exterior vent 28 takes the form of a plurality
of perforation holes in both the front and rear walls of the vent
channel 26. The exterior vent 28 may consist of any suitable means
to allow air to escape the maze vent channel 26 to the exterior of
the bag. The vented seal gap 24 should be offset from the exterior
vent 28 to inhibit loss of powered or granular material contained
within the bag 10.
[0046] FIG. 2 depicts an alternative embodiment with additional
heat seals placed substantially perpendicular to the solid heat
seal 20 and the interrupted heat seal 22 to create maze blocks 30
in the vent channel 26. The maze blocks 30 alternate in
communication with either the second heat seal 22 or the first heat
seal 20. Adjacent maze blocks 30 define a chamber 32 between them.
The number of chambers 32 is dependent on the number of maze blocks
30 with an embodiment having multiple maze blocks 30 having a
plurality of chambers 32.
[0047] An alternate embodiment, shown in FIG. 3, may be employed
when it is not desirable to have a vented bag. When the contents of
the bag are toxic or hazardous, it may be preferable to assure that
no product escapes the bag. In this case, rupture of the bottom
seal is prevented by providing a double reinforced seal as shown in
FIG. 3. In this embodiment, two solid heat seals 20 are used to
seal the bottom of the poly bag.
[0048] It should be understood that the maze vent is adaptable to
many variations and configurations and still be within the scope of
the present disclosure. As illustrative examples only, and in no
way intended to limit the scope of the present disclosure, FIGS. 4a
through 4k show multiple configurations for the maze vent. FIG. 4a
shows a poly bag 10 with a maze vent having an interrupted heat
seal 22 with two vented seal gaps 24 located at either side of the
seal, and the exterior vent 28 comprising a plurality of
perforations located at substantially the center of the vent
channel 26. FIG. 4b shows a maze vent having an abbreviated heat
seal 34. The abbreviated heat seal 34 is located between the solid
heat seal 20 and the interrupted heat seal 22. The abbreviated heat
seal 34 is aligned with and longer than the vented seal gap 24 so
that portions of the abbreviated seal 34 are vertically aligned
with portions of the interrupted heat seal 22 immediately adjacent
to the vented seal gap 24. FIG. 4c is a variation of the maze vent
of FIG. 4a with the addition of maze blocks 30 in cooperation with
the interrupted heat seal 22 on either side of the exterior vent
28. FIG. 4d is a variation of the maze vent of FIG. 4c, adding a
maze block 30 in cooperation with the solid heat seal 20 between
the perforations of the exterior vent 28. FIG. 4e shows a variation
of the maze vent of FIG. 4b, adding maze blocks 30 in cooperation
with the interrupted 22 and solid 20 heat seals between the
abbreviated heat seal 34 and the exterior vent 28. FIG. 4f shows a
maze vent having a substantially centered vented seal gap 24 and an
abbreviated heat 34, with an exterior vent 28 on either side of the
abbreviated heat seal.
[0049] FIG. 4g is another embodiment of the maze vent, having two
interrupted heat seals 22 wherein the vented seal gap 24 in each
interrupted seal is located adjacent to an opposite side of the
poly bag. In the embodiment of FIG. 4g, the exterior vent 28 is
vertically aligned with the vented seal gap of the innermost
interrupted heat seal.
[0050] FIGS. 4h through 4k show embodiments of the maze vent having
two interrupted heat seals 22 and no solid heat seal. The external
vent, therefore, comprises a seal gap in the bottom heat seal.
Instead of air being vented through the sides of the poly bag, the
gap in the bottom heat seal allows air to vent out the bottom of
the tubular poly bag body. FIG. 4h shows a maze vent having two
interrupted heat seals 22, with the vented seal gap 24 and the
exterior vent located at opposite sides of the poly bag. FIG. 4i
shows a maze vent with an inner interrupted heat seal having two
vented seal gaps 24 located at opposite ends of the heat seal and
an outer interrupted seal with the exterior vent 28 located
substantially in the center. FIG. 4j shows a maze vent having an
inner interrupted heat seal having a vented seal gap 24 offset to
one side of the seal and an outer interrupted heat seal with two
exterior vents 28 both offset to the opposite side of the poly bag
as the inner seal gap. FIG. 4k shows a maze vent with an inner
interrupted heat seal having a vented seal gap 24 located
substantially in the center of the inner heat seal and an outer
interrupted seal with the exterior vents 28 located at opposite
ends of the outer heat seal.
[0051] Additionally, the present disclosure is directed towards a
method for manufacturing such a poly bag with a maze vent. The
method for manufacturing a bag having a maze vent as described
herein requires modification of a Windmoeller & Holscher
(W&H) Rotaliner, a machine known in the art. A W&H
Rotaliner has a sealing drum housing five sealing stations. Each
sealing station has a sealing bar with a first sealing surface and
a second sealing surface spaced apart and substantially parallel to
each other. Each sealing station makes one set of seals across the
bottom of the polyethylene tube per bag. The rotating seal bar
makes a series of five bags before a bar has rotated back to its
original position. A notch is machined in the second sealing
surface corresponding to the inner heat seal 22 creating the vented
seal gap 24.
[0052] Polyethylene or other suitable material film is extruded
into tubes and compressed flat forming a front wall and a rear
wall. The flattened tube is then fed into the modified W&H
Rotaliner wherein the first bottom heat seal 20 and the second
inner heat seal 22 are made across the bottom end of the poly tube,
and the exterior vent 28 is formed by making perforation holes
between the seals. Perforation holes may be formed by any suitable
means known in the art including mechanical or needle perforation,
electrical discharge or laser. Additionally, although the
perforations generally described herein as penetrating both the
front and rear walls of the vent channel 26, it is also envisioned
that perforations of only one wall, such as by controlled laser
machining, also fall within the scope of this disclosure.
[0053] The maze blocks 30 are formed by making at least one maze
block surface on the sealing bar. This is done by welding at least
one bead of metal, in communication with and substantially
perpendicular to either the first heat sealing surface or the
second heat sealing surface. The weld bead or beads are then
machined to proper dimensions. In one embodiment, the first maze
block surface is in communication with and substantially
perpendicular to the second heat sealing surface. The second maze
block surface in communication with and substantially perpendicular
to the first heat sealing surface. Additional maze block surfaces
may be added, alternating in communication with the second heat
sealing surface and the first heat sealing surface.
[0054] In one embodiment, the heat seals 20, 22 and the maze blocks
30 each are typically 1/16 inch wide. The solid bottom seal 20 is
typically located 5/8 inch above the bottom edge 16 of the
flattened poly tube. The inner seal 22 is typically located 1-1/8
inch above the bottom seal 20. The vented seal gap 24 in the inner
seal 22 is typically located 3 inches from one of the side folds 12
or 14 in the poly tube and is typically 1/8 inch to 1/4 inch wide.
The perforation holes forming the exterior vent 28 are typically
located to be centered 2 inches from the fold in the poly tube
opposite the side where the vented seal gap is located.
[0055] In one embodiment having maze blocks 30, the first maze
block is typically located 2 inches inward from the vented seal gap
24 and in communication with the interrupted heat seal 22.
Additional maze blocks may be located typically in succession at 4
inch intervals, alternating in communication with the first heat
seal 20 and the second heat seal 22. The maze blocks typically are
3/4 inch long and 1/16 inch wide. However, in alternate
embodiments, such as those shown in FIGS. 4c and 4d, maze blocks 30
may be positioned at the end of heat seal 22 directly adjacent to
the vented seal gap 24.
[0056] In the disclosed embodiments, the microperforation holes
forming the exterior vent 28 are typically 1 mm in diameter and
located to be centered 2 inches from the side fold opposite to the
vented seal gap 24 and at least 1/4 inch above the solid bottom
seal 20. It is envisioned that from 2 to about 10 perforations
provide an optimal range for a variety of bag contents to be vented
although any number of perforations may be used and still fall
within the scope of the present disclosure.
[0057] After material is introduced into the poly bag 10, any
trapped air is allowed to pass through the vented seal gap 24, into
the vent channel 26, and is exhausted to the exterior of the bag
through the exterior vent 28. Any material that passes through the
vented seal gap 24 into the vent channel 26 is trapped within. In
an embodiment having multiple maze blocks 30, chambers 32 are
formed between adjacent maze blocks, which retain material that has
entered the vent channel 26, inhibiting it from reaching the
exterior vent 28.
[0058] In addition, the poly bag of the present disclosure may be
incorporated as part of a multi-component flexible package. For
example, multi-ply paper bags have long been known in the art. Such
bags are generally formed from two or more layers of paper bonded
together and folded to form a bag. One type of such bag is a
"satchel bottom" type bag. A satchel bottom bag formed from
multiple paper plies is folded at the bottom and secured by
adhesive. When the bag is opened, the bottom is flat, allowing the
bag to stand while being filled. A satchel bottom bag may be formed
with or without side gussets. Satchel bottom bags may have a
plastic liner for containing granulated or powdered product
therein.
[0059] The poly liner having a maze vent as described herein, may
be incorporated into a satchel bottom multi-ply paper bag as a
bag-within-a-bag for packaging bulk granulated or powdered
material. FIG. 5 shows such a satchel bottom bag 50, with a poly
liner 10 disposed within a multiple ply outer tube 52. The multiple
ply outer tube 52 is formed from a plurality of contiguous
laterally offset plies 54, 56, and 58. The plies 54, 56, and 58 are
made of a non-heat sealable material, preferably paper, such as
used in well-known industrial packaging bags sold by Bemis Company,
Inc. under its trademark AIRE-TITE.
[0060] The inner poly liner 10 comprises a seamless heat sealed
tube, as described herein, that is fed to a bag-making device,
which forms a bag blank. The inner tubular ply 10 is narrower in
width than one-half the perimeter of the paper ply 58. This results
in a lateral space, or gap, between the poly liner 10 and inner
most paper ply 58. The tubular blank is generally designated as 60,
as shown in FIG. 6, which blank may be produced on a conventional
stepped end tuber device. The overlapping edges of the multiple
paper plies 54, 56, 58 are adhesively bonded to form the seams
along the overlaps, preferably by applying a hot melt adhesive. As
the blank 60 is formed, the poly liner 10 is circumferentially
bonded at 62 adjacent the top edge of the paper ply 58, which ply
is the innermost contiguous paper ply. The bonds 62 are a series of
dots of adhesive around the outer circumference of the poly liner
10 generally near the open end. However, below the bonds 62, the
poly liner 10 is freely and non-attachably retained within the
paper tube 52, except for temporary adhesive at the back side and
near the bottom of the tube blank 60, which momentarily aid in the
bottom folding process to form the bag. After completion of the
bag, they serve no function, dissipate, and do not impede the loose
folding of the bag, or its ability to be retained in a fully
detachable manner within the paper plies. The paper plies 54, 56,
58 are bonded together by dots of adhesive extending
circumferentially around and near the top open end of the blank 60,
as shown at reference numerals 64, 66. The dots of adhesive 64 are
provided to adhere ply 54 to ply 56 and dots of adhesive 66 are
provided to attach ply 56 to ply 58. The line of dots of adhesive
64, 66 are also longitudinally offset front to back due to the
stepping of the paper plies 54, 56, 58.
[0061] The embodiment of the open top in FIG. 5 has a stepped
arrangement of the plies 54, 56, 58; however, a flush cut top,
wherein the plies 54, 56, 58 are cut straight across with the top
of the poly liner 10 to provide a common upper periphery, is also
acceptable. Typically, a bag having flush-cut plies would be closed
by sewing; however, the poly liner 10 would still be heat sealable
and severable.
[0062] The closure of the open top of FIG. 5 is accomplished by
reactivation of a hot melt adhesive strip 68 located on ply 56 and
a hot melt adhesive strip 70 located on ply 58. The hot melt
adhesive strips on the stepped front and back sides are
longitudinally offset due to the stepping, so that the upper end
may be passed through a folding machine, and by means of pressure
rollers, the stepped plies 54, 56, 58 are overlapped and adhesively
joined in a standard way as explained in U.S. Pat. No.
5,281,027.
[0063] Also, in regard to closing the top end, the upper end of the
poly liner 10 would be heat sealed to closure and then, in
preferred form, severed by pressure rollers applied to the exterior
of the paper ply 58, whereby the poly liner 10 will detach below
the line of adhesive dots 62 to result in the freely detachable
arrangement of the pouch 10 as a bag-in-a-bag.
[0064] It should be understood that other types of closures are
alternately envisioned for the open end of the present bag 60,
including a pinch-type closure, adhesive closures other than
reactivatable hot melts, or mechanical closures, such as staples,
clasps, zipper assemblies, etc. The preferred form of the
invention, regardless of how the paper plies are closed, envisions
the heat sealing and severance of the top of the poly liner 10 so
that the bag is detached thereat.
[0065] In connection with any of these types of open end closures,
the formation of the satchel bottom of the bag will now be
described as shown in FIGS. 6 through 10.
[0066] As previously noted, the bag blank 60 is the first step of
forming the satchel bottom. FIG. 6 is the "back" side of the bag 50
for purposes of explanation. Slits are first cut through the front
and back sides of exterior ply 54 whereby two parallel slits 84 are
made in the front side, and two parallel slits 84 are made in the
back side of ply 54. Next, two parallel slits 86 are cut through
both the front and back plies 56 as shown in dashed lines in FIG.
6. In the disclosed embodiment, the slits 84 are about 3 inches
long, made about 4 to 4-1/2 inches inwardly of the lateral edges of
the bag. The slits 86 are approximately 2-1/2 inches long and
inwardly parallel to slits 84 at about 3/4 to 1 inch. The width of
the bag 50 measured across the blank 60 at the outer ply 54 is
standard size in the range of about 19-1/2 to 20 inches. Each pair
of slits is cut through the bottom edge of the respective ply.
These dimensions are useful for understanding the preferred
embodiment, but are not to be understood as limitations to the
invention. While the preferred embodiment has a non-slit innermost
ply 58 and two overlying slit plies 54, 56, the invention envisions
a bag 60 with from 2 to 6 paper plies overlying the ply 58; the
inner ply 58 being non-slit and the others being slit wherein each
ply is slit inwardly at about a 1/2 to 1 inch distance parallel to
the slits of the preceding adjacent overlying ply. The slits are
sequentially shorter by 1/4 to 3/4 inch less than the preceding
overlying ply. The goal is to optimize the lateral distance between
the slits on sequential plies so that later exposed geometric zones
of adhesion surfaces are maximized for effective bonding.
[0067] A gap laterally offsets the poly liner 10 from the plies 52
by 1/4 inch in the exemplary embodiment. As part of the blank
forming process, the poly liner 10 is heat sealed closed along its
lower edge as previously described herein, the bottom edge of the
poly liner 10 being closely adjacent and parallel to the lower edge
of the innermost ply 58.
[0068] As shown in FIGS. 6 and 7, a main score or crease line 72 is
made transversely across the outer tube 52 and thereby across all
paper plies 54, 56, 58. Also with reference to FIG. 6, in the
disclosed embodiment, the main score line 72 is made about 8 inches
upward from the bottom edge of the front side outer ply 54.
[0069] In FIG. 7 the satchel bottom of the bag takes on a more
clearly definable form and is generally denoted by reference
numeral 70. A score line 72 will become the transverse center axis
of the bottom of the satchel bottom as will be understood
hereinafter. Plies 54, 56, 58 are folded back with the poly liner
10 only folded to one side of the main score line 72. Thus, the
poly liner 10 is retained at one side of the main score line and is
tucked in triangular folds 10a, 10b resulting from the diagonal
fold lines 74,76 of the outer tube 60.
[0070] The back of plies 54, 56, 58 are similarly arranged to
create diagonal fold lines 78, 80. It will be apparent that the
non-slit innermost paper ply 58 maintains a continuous lower edge
generally denoted at 82. The paper plies 54, 56, 58, in addition to
the poly liner 10, have the diagonal bend lines 74, 76, 78, and 80,
in common, which, by virtue of the stepped arrangement of the outer
tube 52 and the slits 84, 86, create various symmetric geometric
exposed zones for adhesion as shown. These zones will be
subsequently functional as areas of very effective adhesive mating
for completing the satchel bottom 70. The blank 60 for forming the
satchel bottom 70 is not symmetrical about the main score line 72
but is symmetrical about the longitudinal central axis L of the
blank 60.
[0071] Secondary score lines 88, 90, which are equidistant from and
parallel to the main score line 72, are shown in FIG. 8. In the
disclosed embodiment, these secondary score lines 88, 90 are spaced
about 3 inches to either side of the main score line 72. Since the
stepping of the plies 54, 56, 58 longitudinally offsets the front
and back plies (FIGS. 7 to 9), the relative upward folding of the
back plies causes the folds above score line 72 to form shorter
flaps than front side ply flaps below score line 72. In the
disclosed embodiment, the offset of the front side to back side
plies caused by the stepping of the plies 52 is about 1 inch.
Thereby, when the secondary score lines 88, 90 are formed, the
portion of the front side plies below score line 90 has a greater
length than the back side plies above score line 88, as would be
understood with reference to FIG. 7. The score lines 72, 88, 90 are
all shown in FIG. 7 for purposes of explanation. It should be
understood that the poly liner 10 will receive a crease along the
score line 88, as well as the paper plies that envelop it.
[0072] For other embodiments, the satchel bottom is dimensioned as
shown in FIG. 8. Dimension "A" represents the slit length
corresponding to slits 84. Dimension "A" is dependent on the
satchel bottom depth shown as dimension "C" as given by the
equation A=(C+1/8 inch)-(C.times. 13/16), which reduces to A= 5/16
C. Dimension "B" is the distance from the bag edge to the edge of
the innermost paper ply. Dimension "B" is 1/8 inch greater than the
satchel bottom depth "C." The patch length is represented by
dimension "D." Dimension "D" is given by the equation D=(W-C)+1
inch, wherein "W" is the width of the bag from one edge to the
other. Dimension "D" includes 1 inch for a cuff, shown as dimension
"F." Dimension "E" is the distance from the apex to the slit as
shown in FIG. 8 and is equal to dimension "A."
[0073] The next stage in the formation of the satchel bottom 70 is
illustrated in FIG. 9. An application of adhesive 92 is shown with
stippling in the geometric zones of adhesion on the papers plies
54, 56, 58 created by the slitting 84, 86 and the folding of the
plies about the main score line 72. As stated, this folding creates
the diagonal folds 74, 76, 78, 80 whereby a very effective series
of geometrically exposed opposable surface areas are created,
allowing for strong contact bonding of the adhesive 92.
[0074] This formation or pattern also allows for the free
non-adhesive retention of the folded poly liner 10, as shown at the
broken-away triangular shaped folded portions of the paper plies
(FIG. 7) that cover parts 10a and 10b of the poly liner. It will be
seen that the poly liner 10 above score line 72 assumes a generally
trapezoidal shape bounded by the score line 72, diagonal folds 74,
76, and a portion of the innermost paper ply 58, generally along
the edge 94 extending between the diagonal folds 74, 76.
[0075] The adhesive 92 preferably comprises a hot melt glue and is
applied in four zones as shown in FIG. 9, so as not to contact the
poly liner 10. The zones are located outwardly of the secondary
fold lines 88, 90 and extend to the diagonal fold lines 74, 76, 78,
80. Flaps 116, 118 formed by slitting paper plies 54 along 84 have
adhesive at both flap ends, but no adhesive is applied along the
length of the flap.
[0076] For bags having an easy opening feature, an opener strip 120
is placed against the diagonally folded plies 52 of the satchel
bottom before the flaps 116, 118 are folded inward.
[0077] This is so that the opener strip 120 lies within the folded
flaps 116, 118 of the satchel bottom 70.
[0078] The back side plies above score line 72, as shown in FIGS. 8
and 9, are rotated or folded about secondary score line 88. This
step folds the back side paper plies 54, 56, 58 generally onto
themselves which also rotates and secures the poly liner along the
fold line 88 thereunder. At this stage, the inner poly liner 10 is
folded along diagonal bends 74, 76 and at the crease formed along
secondary fold line 58.
[0079] The ply flaps of the front side of the paper plies 54, 56,
58 about the secondary fold line 90, thereby rotates the adhesive
92 to overlie the paper plies 54, 56, 58 of the back side of the
bag 60. This step also folds the respective portions of the front
side flaps onto themselves. Each of the surfaces with reference
numeral 54 indicate the exposed bottom surfaces of the satchel
bottom which are comprised of the outer paper ply 54.
[0080] To further reinforce the satchel bottom, a patch 122 may be
adhesively fixed to the outside of the bottom of the bag as shown
in FIG. 10. The patch may be a single ply of kraft paper adhesively
fixed to the exterior of the satchel bottom, or may be of other
suitably strong material to reinforce the satchel bottom 70.
Reinforcement may be desirable because of foreseeable rough
handling or to compensate for the lack of adhesive on the flaps
when combined with an easy opening feature. The patch 122 is placed
on the outside of the folded flaps to reinforce the satchel bottom.
The patch is secured by adhesive 124 placed in zones along the long
edges of the patch. The embodiment shown in FIG. 10 has the
adhesive 124 oriented in strips located on either side of the
patch's long axis.
[0081] It may be desirable to have an easy-opening feature on the
bag. In this embodiment, the patch has a cuff 126 located at one of
its lateral side edges. The cuff 126 is defined by a pair of slits
128, 130 in the patch approximately 1 inch long. The opener strip
120 placed laterally under the flaps 116, 118 of the satchel bottom
extends to cooperate with the cuff 126 area of the patch 122. The
cuff area 126 is designed to allow a user to lift the cuff away
from the satchel bottom 70 and grasp the opener strip 120 to pull
and tear open the bottom of the bag. The opener strip 120 may be
made of string, plastic or other suitable material. The opener
strip 120 operates to tear the flaps 116, 118 of the satchel bottom
and the patch 122 when pulled by a user to open the bag.
[0082] Upon the drying of the adhesive 92, the satchel bottom 70 is
completed. The steps for forming the tube blank 60 are thereby also
completed. The multi-ply plastic lined bag with satchel bottom 50
is now in a flat blank stackable form, ready for shipment to the
manufacturer, packer, or the like, for filling with a product.
[0083] When the bag 10 is ready for filling, the satchel bottom 70
is unfolded to form a flat rectangular bottom shape as illustrated
in FIG. 5, whereby the open mouth top is positioned for the
introduction of a product, typically a dry granulated powder, such
as milk granules, or the like. The short sides of the rectangular
bottom are the overlapped edges of the paper plies, generally
denoted at 102, 104 in FIG. 5. The longer edges of the rectangular
bottom are denoted at 106, 108, which are the fold lines of the
paper plies along secondary score lines 88, 90, respectively. At
each corner of the bag, adjacent the short edges 102, 104, a
triangle is formed with the diagonal fold lines, as at 110, 112,
noted in FIG. 5. The lateral edge of the bag 50 will taper to meet
the intersection of the diagonal bend lines 110, 112, shown at one
side of the bag for illustration, at reference numeral 114 in FIG.
5. The mirror image of course is formed on the opposite side of the
bag, not shown.
* * * * *