U.S. patent application number 13/346990 was filed with the patent office on 2013-07-11 for pouch having concavely-curved corners.
The applicant listed for this patent is Gautam BHATTACHARJEE, Zhe Ma. Invention is credited to Gautam BHATTACHARJEE, Zhe Ma.
Application Number | 20130177265 13/346990 |
Document ID | / |
Family ID | 48743985 |
Filed Date | 2013-07-11 |
United States Patent
Application |
20130177265 |
Kind Code |
A1 |
BHATTACHARJEE; Gautam ; et
al. |
July 11, 2013 |
POUCH HAVING CONCAVELY-CURVED CORNERS
Abstract
A pouch has a sheet containing at least one layer of a film
material. The sheet forms a tube that is closed with a seal to form
a volume. The seal contains a first edge and the sheet contains a
second edge in connected relation to the first edge. A curved seal
joins the first edge with the second edge. A sealing jaw and a
method for forming such a pouch is also described.
Inventors: |
BHATTACHARJEE; Gautam;
(Beijing, CN) ; Ma; Zhe; (Beijing, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BHATTACHARJEE; Gautam
Ma; Zhe |
Beijing
Beijing |
|
CN
CN |
|
|
Family ID: |
48743985 |
Appl. No.: |
13/346990 |
Filed: |
January 10, 2012 |
Current U.S.
Class: |
383/121 |
Current CPC
Class: |
B29C 66/81427 20130101;
B29C 65/74 20130101; B29C 66/4312 20130101; B29C 66/849 20130101;
B65D 75/12 20130101; B29C 65/18 20130101; B29C 66/71 20130101; B29C
66/71 20130101; B29C 66/71 20130101; B29C 66/71 20130101; B29C
66/71 20130101; B29C 66/71 20130101; B29C 65/08 20130101; B29C
66/72321 20130101; B29C 66/71 20130101; B29C 66/73711 20130101;
B65D 75/48 20130101; B29K 2023/06 20130101; B65D 75/566 20130101;
B29K 2023/12 20130101; B29K 2023/083 20130101; B29C 66/81435
20130101; B29C 66/71 20130101; B65B 51/30 20130101; B29C 66/133
20130101; B29C 66/244 20130101; B29K 2067/003 20130101; B29K
2077/00 20130101; B29K 2023/0625 20130101; B29K 2023/18
20130101 |
Class at
Publication: |
383/121 |
International
Class: |
B65D 30/10 20060101
B65D030/10 |
Claims
1. A pouch comprising: a. a sheet comprising at least one layer of
a film material, the sheet forming a tube; and b. a seal forming
the tube into a volume, wherein the seal comprises a first edge,
wherein the sheet comprises a second edge in connected relation to
the first edge, and wherein a curved seal joins the first edge with
the second edge.
2. The pouch according to claim 1, wherein the curved seal forms a
volume corner, and wherein the pouch comprises a plurality of
volume corners.
3. The pouch according to claim 1, wherein the pouch is formed by
an autopacking machine.
4. The pouch according to claim 1, comprising a granular product
therein.
5. The pouch according to claim 1, comprising a liquid product
therein.
6. The pouch according to claim 1, wherein the film material is
from about 15 .mu.m to about 220 .mu.m thick.
7. The pouch according to claim 1, wherein the curved seal has a
radius of curvature of greater than about 3 mm, preferably from
about 10 mm to about 30 mm.
8. The pouch according to claim 1, wherein the volume is
substantially airtight.
9. The pouch according to claim 4, wherein the granular product is
a granular laundry detergent.
10. A sealing jaw comprising: a. a sealing arm comprising a sealing
area, the sealing area comprising: i. a first edge-forming element;
and ii. a curved seal-forming element adjoining the first edge
forming element; and b. a receiving arm, wherein the sealing arm
and the receiving arm are complementary and wherein the sealing arm
and the receiving arm may interact to seal a sheet
therebetween.
11. The sealing jaw of claim 10, wherein the sealing arm comprises
a heating element.
12. The sealing jaw of claim 10, wherein the receiving arm
comprises a heating element.
13. An autopacking machine comprising the sealing jaw according to
claim 10.
14. A method for sealing a pouch comprising the steps of: a.
providing a sheet; b. forming a tube from the sheet having a
leading edge; c. sealing the leading edge to form a leading edge
seal; d. filling the tube with a predetermined amount of a product;
e. sealing the tube to form a trailing edge seal; and f. cutting
the tube after the trailing edge seal to form a pouch comprising a
volume between the leading edge seal and the trailing edge seal,
wherein the volume comprises the product, wherein at least one of
the first seal or the second seal comprises a first edge and a
curved seal adjoining the first edge.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to pouches. Specifically, the
present invention relates to sealed pouches formed from a film
material.
BACKGROUND OF THE INVENTION
[0002] Pouches are typically formed of a laminate or a film and may
be used for holding many types of items such as food, shampoos,
detergents, medicines, etc. In order to prevent them from leaking,
they are often sealed on all sides to form a fixed volume to
contain a product, for example a granular or liquid detergent.
However, it is always a challenge to balance pouch waste and
strength against bursting and leakage. The strength of a seal is
directly proportional to the sealing area itself. If the pouch is
sealed with too much sealing area on the sides, then the given
volume per area of film is smaller, leading to wasted film.
However, if the sealing area is too narrow, then the pouch will
easily burst if dropped or if jostled against other pouches during
shipment or display.
[0003] Typically a pouch is sealed with a straight seal forming
approximately a 90.degree. angle. While this is an efficient means
of sealing the top and bottom, it has now been found that this
leads to easy puncture of the pouch's body in response to a sudden
impact, such as when the pouch is dropped, when something else is
dropped onto the pouch, etc. Such a sudden impact could occur at
any time prior to opening for use, such as during the
filling/manufacturing process, shipping, storage, transportation,
display, etc. Such an undesirable puncture leads to waste,
messiness, product loss, etc. and in some cases, a customer may
even refuse to purchase a product in a punctured pouch.
[0004] Existing methods to solve this problem employ stronger
sealing techniques and adhesives, stronger films and pouch
materials, and/or different laminate layers within a film material.
However, all of these methods typically increase complexity, and
require special capability beyond that available at the machine
where the forming, filling and sealing takes place.
[0005] Accordingly, the need exists for an improved pouch which is
more resistant to punctures, especially while employing existing
film materials, sealing processes, and sealing machinery.
SUMMARY OF THE INVENTION
[0006] The present invention relates to a pouch having a sheet
containing at least one layer of a film material. The sheet forms a
tube that is closed with a seal to form a volume. The seal contains
a first edge and the sheet contains a second edge in connected
relation to the first edge. A curved seal joins the first edge with
the second edge.
[0007] A sealing jaw contains a sealing arm and a receiving arm.
The sealing arm contains a sealing area further containing a first
edge-forming element and a curved seal-forming element adjoining
the first edge-forming element. The first edge-forming element
forms a curved seal adjacent to the first edge-forming element.
[0008] A method for sealing a pouch includes the steps of providing
a sheet, forming a tube from the sheet having a leading edge,
sealing the leading edge to form a leading edge seal, filling the
tube with a predetermined amount of a product, sealing the tube to
form a trailing edge seal, and cutting the tube after the trailing
edge seal to form a pouch. The leading edge seal and the trailing
edge seal form a volume therebetween and the volume contains the
product. At least one of the leading edge seal or trailing edge
seal contains a first edge and a curved seal adjoining the first
edge.
[0009] It has now been found that the invention can significantly
reduce puncturing at the body by blunting the force when, for
example, the filled pouch is dropped or jostled against other
pouches during shipment or display.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] While the specification concludes with claims particularly
pointing out and distinctly claiming the invention, it is believed
that the invention will be better understood from the following
description of the accompanying figures in which like reference
numerals identify like elements, and wherein:
[0011] FIG. 1 is a front view of an embodiment of the pouch
herein;
[0012] FIG. 2 is a cut-away view of the pouch of FIG. 1, as seen
along line 2-2;
[0013] FIG. 3 is a front view of an existing comparative pouch;
[0014] FIG. 4 is a front view of an existing comparative pouch;
[0015] FIG. 5 is a front view of an existing comparative pouch;
[0016] FIG. 6 is a front view of an embodiment of the sealing arm
according to the invention herein;
[0017] FIG. 7 is a front view of an embodiment of the receiving arm
according to the invention herein;
[0018] FIG. 8 is a front view of an embodiment of the pouch
herein;
[0019] FIG. 9A is a partial front view of an embodiment of the
pouch herein; and
[0020] FIG. 9B is a partial front view of an embodiment of the
pouch herein.
[0021] The figures herein are not necessarily drawn to scale.
DETAILED DESCRIPTION OF THE INVENTION
[0022] All temperatures herein are in degrees Celsius (.degree. C.)
unless otherwise indicated. As used herein, the term "comprising"
means that other steps, ingredients, elements, etc. which do not
adversely affect the end result can be added. This term encompasses
the terms "consisting of" and "consisting essentially of".
[0023] As used herein, the term "fabric enhancer" includes a
composition intended to provide an improved scent, softness,
anti-static benefit, and/or shape-retention benefits to a fabric,
such as a fabric conditioner, and/or a fabric softener. Such a
fabric enhancer is typically intended to function in the rise cycle
of a laundering process.
[0024] This disclosure relates to a pouch having a sheet containing
at least one layer of a film material. The sheet forms a tube that
is closed with a seal to form a volume. The seal contains a first
edge and a second edge adjoining the first edge. The first edge
forms a curved seal with the second edge. This disclosure also
relates to methods and equipment for making such a pouch.
[0025] Referring to the Figures herein, FIG. 1 is a front view of
an embodiment of the pouch, 100, containing a sheet, 120, formed
into a tube (see FIG. 2 at 142). The pouch is formed of a sheet
which is in turn formed from at least one film material typically
selected from the group consisting of polyamide (nylon),
polyethylene, polypropylene, ethyl-vinyl-acetate,
poly-4-methylpentene-1, a microporous membrane, and a combination
thereof; or polyamide (nylon), linear low-density polyethylene, an
oriented polypropylene, polyethylene terephthalate, and a
combination thereof. Generally, softer and more stretchy film
materials also may reduce rupturing, and therefore extrusion
lamination, co-extrusion lamination, and blends of film materials,
such as polyethylene and polyethylene terephthalate are useful
herein.
[0026] The film material may also be affixed to and/or contain a
metal therein, and/or be a metalized film. Film materials are well
known in the art and may further contain resins, laminates, printed
artwork, additives (i.e., UV blockers, antimicrobials, dyes,
pigments, etc.), etc. Suitable film materials are available from
various suppliers worldwide such as 3M Company (St. Paul, Minn.,
USA), Du Pont Co. (Wilmington, Del., USA), Toppan Insatsu Co.
(Tokyo, Japan), Gelman Sciences Company (Ann Arbor, Mich., USA),
and many other suppliers worldwide. The sheet herein may contain
either a single layer or contain multiple layers of the same, or
different film material(s), so long as it remains sealable. The
sheet is typically from about 15 .mu.m to about 220 .mu.m, or from
about 20 .mu.m to about 200 .mu.m, or from about 25 .mu.m to about
160 .mu.m thick. Each individual film material may be oriented, or
random as desired.
[0027] Multiple layers of film materials may be joined together to
form a sheet with multiple properties and/or benefits. In such
cases, it is known in the art to join the multiple layers together
by, for example, lamination, heat sealing, ultrasonic sealing,
gluing, pressure sealing, etc.
[0028] The sheet, 120, may then be formed into a pouch, 100, by
pulling and/or stretching the sheet, 120, around a forming tube
(not shown) to form a tube out of the sheet, 120. The tube is
formed by sealing the edges of the sheet, 120, in any direction
such as the machine direction at any point or continuously, and/or
by sealing the edges in the cross direction at either the leading
edge and/or the trailing edge. The forming tube doubles as a
filling tube, through which the product to be contained in the
pouch is then filled into the tube (see FIG. 2 at 142). The sheet
is pulled or advanced in the machine direction (A), and the sealing
jaw (comprising of the sealing arm and receiving arm) (see FIG. 6
at 150, and FIG. 7 at 170) simultaneously seals and cuts the
trailing portion of the tube (see FIG. 2 at 142) in the cross
direction (B). This simultaneously releases the filled pouch and
forms a new seal, 122, at the leading edge, 124. Machinery and
techniques for forming such filled pouches are often referred to as
"autopacking machines" and are well known in the art and are
available from multiple suppliers around the world. Autopacking
machines are also often described in the industry as in-line
packing and sealing machines, and/or form-fill-seal (FFS)
machines.
[0029] Thus, in FIG. 1, the sheet, 120, is sealed in the machine
direction (A) to form a fin seal, 126, resulting in the continuous
production of a tube (see FIG. 2 at 142). The leading edge, 124, is
then sealed by a sealing jaw (comprising of the sealing arm and
receiving arm) (see FIG. 6 at 150, and FIG. 7 at 170), typically in
the cross direction (B), to form the volume (see FIG. 2 at 144)
closed at the seal, 122.
[0030] In FIG. 1, the seal, 122, is a leading edge seal, 122', and
contains a first edge, 128, and a second edge, 130. The first edge,
128, and the second edge, 130, form a curved seal, 132,
therebetween. In FIG. 1, in an embodiment, all of the 4 corners of
the pouch contain a curved seal, 132, and the curved seal has a
radius, r, which defines the curvature of the curved seal. The
radius, r, of the curved seal is typically greater than about 3 mm,
or from about 10 mm to about 30 mm, or from about 5 mm to about 20
cm, or from about 5 cm to about 20 cm. Without intending to be
limited by theory, it is believed that too small of a radius is
effectively the same as a right angle, whereas too large of a
radius ends up reducing the effective volume that is able to
contain the product in the pouch. Thus, the ranges above are
believed to balance the puncture resistance with the effective use
of the film material. Further, the ranges above for the radius of
the curved seal work well for both small and large bags since the
purpose of the curve seal is to blunt the impact of the right
angle. The curved seal, 132, is concavely-curved, meaning that the
center, c, of the radius, r, is in the volume, 134, that contains
the product (not shown), rather than the center, c, being located
in the seal, 122 (compare, for example, FIG. 5), or even outside of
the pouch, 100. In an embodiment herein, the pouch contains a
plurality of corners, or from about 3 corners to about 6 corners,
or from about 4 corners to about 5 corners, or about 4 corners, and
each corner contains a curved seal. In an embodiment herein the
radius of each curved seal is about the same. In an alternative
embodiment herein, the radius of at least 2 corners, or from about
2 corners to about 4 corners, is different.
[0031] Without intending to be limited by theory, it is believed
that typical pouches contain a right angle, or even an acute angle
at the corners where the leading edge seal and/or the trailing edge
seal meets the edge of the standard pouch (see, FIGS. 3-5). It is
now believed that many punctures of standard pouches (see FIGS.
3-5), such as those containing granular laundry detergents, is
caused by a small amount of granular product that accumulates in
the corner of the pouch, and may contain a little air or other
granular products behind it--which forms a dart like sharp corner
and when the pouch receives an impact, from, for example, dropping,
falling, another pouch hitting it, etc. the small amount of
granular product is forced at a relatively high velocity towards
the corner. As the angle formed by the sides and seal are either
acute or a right angle, the force of the plurality of moving
granules is concentrated to a single point in the corner.
[0032] These multiple, high-velocity impacts may weaken the film
material and/or even cause the body or surface taking the impact to
burst. Thus, even though the individual granules are themselves
quite light, the cumulative impacts to the material in the corner
potentially result in a tearing of the film from within, and cause
the film material at the pouch body to fail, resulting in a pouch
that leaks from the body.
[0033] In contrast, the pouch herein contains a corner area, 134,
where the sheet, 120, is sealed with a curved seal, 132. Without
intending to be limited by theory, it is believed that the curved
seal blunts the force of the plurality of moving granules. It is
also believed that the curved seal distributes this force over a
greater area, instead of concentrating it like a right or acute
angle may do. As a result, the film material maintains its
integrity and is less prone to bursting or failure. A typical pouch
has approximately a rectangular or square 2-dimensional face, and
therefore the pouch edges, 136, will still typically form right
angles, .beta.. Such pouches (see also FIGS. 3-5) are the most
common and the easiest to make. As the curved seal, 132, is
adjacent to a first edge, 128, formed by the seal, 122, this means
that for a typical pouch, 100, herein as shown in FIG. 1 the second
edge, 130, is typically formed by the edge, 136, of the pouch, 100.
The leading edge, 124 and the trailing edge, 138, may contain
similar seals, 122, including similar curved seals, 132. In an
embodiment herein as seen in FIG. 1, the trailing edge seal, 122'',
contains a first edge, 128, a second edge, 130, and a curved seal,
132. One skilled in the art will understand that in some vertical
form/fill/seal (VFFS) machines, the order of the trailing edge and
the leading edge may be reversed, as compared to FIG. 1.
[0034] In FIG. 1, the trailing edge, 138, also contains a plurality
of handle holes, 140, to allow easier carrying of the pouch, 100.
In an embodiment herein, the pouch contains at least 1 handle hole,
or from about 1 handle hole to about 5 handle holes; or from about
2 to about 3 handle holes, or about 2 handle holes. The handle
holes are typically centered above the pouch's center of gravity in
order to make carrying easier. Without intending to be limited by
theory, it is believed that a single handle hole is typically most
convenient for the user; Thus in an embodiment herein, the pouch
contains 1 handle hole. However, if a fin seal, 126, is present,
then cutting such a single handle hole increases the wear and tear
of the cut blade(s) on the sealing arm (see FIG. 7 at 160). Having
an even number of handle holes can reduce the need to cut through
the fin seal, however, having 4 or more handle holes is confusing
to the user. Accordingly, in an embodiment herein the pouch
contains 2 handle holes.
[0035] FIG. 2 is a cut-away view of the pouch, 100, in FIG. 1, as
seen along line 2-2. One can clearly see that the sheet, 120, has
been formed into a tube, 142, by joining the sheet, 120, to itself
at the fin seal, 126. This tube, 142, is also sealed at the far end
by the seal, 122, that then defines a volume, 144. The volume, 144,
can contain a product (not shown) therein to protect it from
spillage, moisture, the outside atmosphere, etc. Thus, in FIG. 2,
the pouch is formed in what is commonly known in the art as a
"pillow pouch" or a "pillow bag". While the pouch may be formed
into other pouches such as gusset bags, wicket bags, standup bags,
etc., it is believed that the puncture problem described herein is
particularly prominent in pillow bags. Accordingly, in an
embodiment of the invention, the pouch is a pillow bag.
[0036] The product (not shown) to be filled into the pouch
typically has a bulk density of at least 250 g/L, or from about 300
g/L to about 1.3 kg/L, or from about 450 g/L to about 1.1 kg/L. In
one aspect, the product is typically a granular product; or a fine
granular product, such as a granular product having a number-median
particle size of from about 10 .mu.m to about 5 mm. In an
embodiment herein, the fine granular product is a granular
detergent, a granular fertilizer, a granular fabric enhancer, a
granular mineral, and/or a granular medicine; or a granular laundry
detergent, and/or a granular fabric enhancer. In another aspect,
the product is a liquid product. The term "liquid" is used herein
to broadly include, for example, mixtures, solutions, dispersions,
emulsions, etc. The liquid may be from low to very high viscosities
including gels and pastes, such as up to about 10,000 mPas, or from
about 100 mPas to about 1000 mPas, or from about 300 mPas to about
500 mPas. The liquid may contain active ingredients suitable for
various applications such as, for example, domestic and consumer
products (e.g., laundry cleaning and treatment, dish and hard
surface cleaning, shampoo, bath additives, etc.). In an embodiment
herein, the liquid product is a liquid laundry detergent, or a
liquid fabric enhancer.
[0037] The volume, 144, may be either airtight or may allow air to
flow into and or out of the volume, 144. In an embodiment herein
the volume is airtight (or substantially airtight) once all the
seals are formed and in place; only upon puncture thereof is air
and/or the granular or liquid product easily let into or let out of
the volume. Such an airtight pouch is typical of current bags
containing, for example, a granular laundry detergent, as described
in the examples. In another embodiment herein, the pouch may allow
air to pass out of the volume, by, for example having a valve, a
seal design allowing air to pass therethrough (see, e.g., US Patent
Publication No. 2009/226573 A1 to Gonzales, et. al., published on
Sep. 10, 2009), and/or having small holes purposely formed into the
pouch. However, in such cases, air typically can escape from the
volume only relatively slowly, and therefore the puncturing problem
at the corners due to a sudden impact still exists. Without
intending to be limited by theory, it is believed that in pouches
where air is allowed to quickly exit the pouch, then the bursting
and/or puncturing problem does not significantly exist.
[0038] The volume typically ranges from (when sealed) at least 500
mL, or from about 500 mL to about 100 L, or from about 800 mL to
about 60 L, or from about 1 L to about 30 L, or from about 1.5 L to
about 20 L. Typically the pouch will contain both the product as
well as air (or another type of gas) therein, because without air
in the package (i.e., a vacuum-packed package), the product does
not move, and therefore problem does not exist. Thus, in an
embodiment herein, the pouch comprises air therein, and the product
in the pouch is not vacuum-packed.
[0039] FIG. 3 shows a front view of an existing pouch, 100',
lacking a curved seal at each volume corner, 146. The pouch, 100',
is a typical pillow bag having a fin seal, 126, and seals, 122, at
the leading edge, 124, and the trailing edge, 138. The edge, 136,
and the seal, 122, form a typical angle, .delta., of substantially
90.degree.. Typically, this angle is repeated at each of the 4
volume corners, 146.
[0040] Similarly, FIG. 4 shows a front view of an existing
comparative pouch, 100', having a substantially continuous seal,
122, all around the perimeter thereof. Such a pouch, 100', is
typically formed of two separate sheets, 120, 120', of film
materials, sealed at all the edges, 136, to form a volume, 144,
therein. Such a pouch, 100', also typically has an angle, .delta.,
of substantially 90.degree. where the seal, 122, forms a volume
corner, 146. Typically, this angle is repeated at each of the 4
volume corners, 146.
[0041] FIG. 5 shows a front view of an existing comparative pouch,
100', with a convexly-curved seal, 148, at each of the volume
corners, 146. This embodiment was allegedly created to solve a
similar puncture problem as described herein; however, it was not
successful. In FIG. 5, the center, c, of the radius, r, is located
in the seal, 122, and not in the volume, 144.
[0042] FIG. 6 shows a front view of an embodiment of a sealing arm,
150, of the present invention. The sealing arm, 150, and the
receiving arm (see FIG. 7, at 170), are opposed to each other,
either permanently or temporarily, to form a sealing jaw (not
shown). The sealing arm, 150, contains a sealing area, 152, for
forming the seal (see FIG. 1 at 122). The sealing area, 152,
further contains a first edge-forming element, 154, connected to a
curved seal-forming element, 156. The curved seal-forming element,
156, has a concave angle with center, c, and a radius, r.
[0043] In the embodiment of FIG. 6, the sealing arm, 150, contains
a heating element, 158, on the back side of the sealing arm, 150,
that keeps the sealing area, 152, hot enough to melt the sheet (see
FIG. 1 at 120). One skilled in the art will understand that many
methods and apparatuses to seal the sheet(s) together to make the
seal (see FIG. 1 at 122), are applicable, such as, heat sealing,
ultrasonic sealing, pressure sealing, adhesive sealing, etc. In an
embodiment herein, the seal is formed by heat sealing and/or
ultrasonic sealing; or heat sealing.
[0044] In FIG. 6, the sealing area, 152, terminates in a cut blade,
160, that cuts the pouch (see FIG. 1 at 100) at the same time the
sealing area, 152, seals the sheet(s) (see FIG. 1 at 120) together.
Where one does not want to actually separate individual pouches,
but instead wants to make them continuous, such as, for example, in
a streamer, the cut blade, 160, may be replaced with a line of
needles or a line of intermittent cut blades, to make, for example,
a perforation. Other methods and elements for making a line of
weakness are also known in the art. Furthermore, as one skilled in
the art would realize, the cut blade(s) should be of sufficient
structural integrity, and durability to both penetrate all layers
of the pouch completely, and also be oriented to easily release the
finished pouch after the seal and perforation is made. In an
embodiment herein, the cut blade is from about 1 cm to about 10
.mu.m, or from about 5 mm to about 20 .mu.m, or from about 2 mm to
about 40 .mu.m in height, as measured perpendicularly from the
surface of the sealing arm, 150. The cutting blade may be straight,
jagged, curved, etc. as desired. In an embodiment herein, the cut
blade may be perpendicular to the surface of the sealing arm, or
may be angled in the machine direction. Without intending to be
limited by theory, it is believed that if the cut blade is
perpendicular to the surface of the sealing arm, then at slower
machine speeds the cut blade will more effectively form the cuts.
However, it is believed that at faster autopacking machine speeds,
a cut blade that is angled in the direction of the package flow may
more quickly release the finished pouch, so as to reducing jamming
of the autopacking machine caused by a failure of the finished
pouch to drop away from the sealing arm.
[0045] In an embodiment herein, a plurality of sealing jaws may be
used such that, for example, a sealing jaw may be present to seal
the top of the pouch and cut it away, while a separate but adjacent
sealing jaw may simultaneously seal the bottom of the next
pouch.
[0046] The sealing arm, 150, also contains optional sealing ridges,
162, which may provide textured seals. Such textured seals may be
desirable in some instances to produce, for example, an easier to
grip seal, to enhance seal strength, aesthetic reasons, etc.
[0047] In an embodiment herein, the sealing jaw is designed so that
it can cut a handle in the seal by, for example, including a handle
cutting element. Such a handle cutting element may also be formed
by, for example, one or more cut blades.
[0048] FIG. 7 is a front view of an embodiment of a receiving arm,
170, of the present invention. The receiving arm, 170, complements
the sealing arm (FIG. 6 at 150), and is a mirror image thereof,
containing a complementary sealing area, 152, which matches with
the sealing arm's sealing area, 152 (see FIG. 6). The receiving
arm, 170, contains a cut channel, 172, which is typically a concave
indentation or depression in the surface of the receiving arm, 170,
that allows the cut blade(s) (FIG. 6 at 160), etc. to punch through
the sheets and form the respective cut, perforation, etc. The
receiving arm, 170, also contains sealing ridges, 162, to
complement those on the sealing arm (FIG. 6 at 150).
[0049] In an embodiment herein, the cut blade(s) is releasably
attached to the sealing arm, so that when it wears out it may be
removed, sharpened and/or replaced without having to fabricate an
entire new sealing arm.
[0050] The sealing arm, 150, the receiving arm, 170, or both
actively interact to form the seal by, for example, heat sealing,
ultrasonic sealing, pressure sealing, etc. as desired, and
therefore contains the appropriate sealing technology therein or
thereupon, such as, for example, a heater, an ultrasonic generator,
a pressure clamp, etc. The sealing arm and the receiving arm are
typically each independently formed of an appropriate durable
material for their uses herein, such as, for example, a metal, a
ceramic, a plastic, and a combination thereof. A sealing jaw
intended for heat sealing should be both strong and conduct heat
well and may be formed of, for example, copper, brass, steel, or
iron, aluminum, etc. Impulse and induction sealing methods are
known in the art and are useful herein. Based on this disclosure, a
sealing arm and a receiving arm according to the present invention
may be custom made by various suppliers and/or machine shops around
the world.
[0051] One skilled in the art will recognize that the sealing jaw
herein may be used on an autopacking machine.
[0052] FIG. 8 shows a front view of an embodiment of the pouch,
100, herein containing a single curved seal, 132, having a
relatively large radius, r, across the entire leading edge, 124,
and a single curved seal, 132, having a relatively large radius, r,
across the entire trailing edge, 138.
[0053] In an alternate embodiment (not shown) a single curved seal
having the same center and radius also forms both the curved seal
of the leading edge and the trailing edge.
[0054] FIG. 9A shows a partial front view of an embodiment of the
pouch, 100, containing multiple curved seals, 132, 132', at the
same volume corner, 146. The seal, 122, forms a first curved seal,
132, having center, c, and radius, r, at the pouch edge, 136. The
seal also forms a second curved seal, 132', having a different
center, c', and radius, r'. Both curved seals, 132, and 132', are
concave, as their centers, c and c', are in the volume, 144.
[0055] FIG. 9B shows a partial front view of an embodiment of the
pouch, 100, containing multiple curved seals, 132, 132', at the
same volume corner, 146. The seal, 122, forms a first curved seal,
132, having center, c, and radius, r, at the pouch edge, 136. The
seal also forms a second curved seal, 132', having a different
center, c', and radius, r'. Between the first curved seal, 132, and
the second curved seal, 132', is a convexly-curved seal, 148,
having a center, c'', and a radius, r''. The center, c'', of the
convexly-curved seal, 148, is located in the seal, 122.
[0056] In an embodiment herein the invention is combined with
additional techniques known in the art, such as a laser-cut, a
half-cut, a score line, embossing, etc. and the known methods and
machinery therefor. In an embodiment herein, a reclosing technology
is combined with the invention herein, to allow easy and efficient
reclosing of the pouch after opening. Such reclosing technologies
are also especially beneficial with larger-sized pouches. Typical
reclosing technologies are known in the art and include plastic
pressure-sensitive zippers, hook and loop fastening systems, zipper
systems, adhesive strips and patches, clips and snaps, locking
systems, etc. For additional technologies useful in combination
with the present invention, see, EP Patent No. 1 409 366 B1 to
Camargo-Parodi, et al., granted on Jun. 21, 2006; and EP Patent
Application No. 07119454.2 To Rogers, filed on Oct. 29, 2007.
Example 1
[0057] Pouches according to FIG. 1 and FIG. 2, are formed on a VFFS
machine from a sheet using sealing jaws similar to that of FIGS.
6-7. The VFFS machine creates all seals by heating up the sealing
jaw to create thermal bonding between the separate sheets. The
sheet is a three layer laminate of the film materials polyethylene
terepthalate, a metallic film (like MYLAR.RTM.), and polyethylene.
The sheet is provided on a roll which feeds into the VFFS machine
and is stretched onto an area where the tube is formed by sealing a
fin seal in the machine direction. The tube has a leading edge
which is sealed to form a leading edge seal using the sealing jaws
according to FIGS. 6-7. A predetermined weight (.about.1.7 kg) of a
granular laundry detergent is filled into and flows down the tube
and the tube is sealed using the sealing jaws of FIGS. 6-7 to form
a filled pillow pouch containing granular laundry detergent. The
process then repeats itself for the next pouch.
[0058] Comparative pouches according to FIG. 3 using similar
materials are formed on a standard VFFS machine, employing a
standard set of sealing jaws. These comparative pouches have
substantially 90.degree. angles at all of the volume corners.
[0059] Bursting was tested by dropping individual bags from a
height of 1.2 m 3 times on three different sides and then also by
dropping then from a height of 1.2 m 3 times packed in poly woven
bags on 3 different faces. The bag was also dropped on another bag
keeping the corner landing on the face of the other bag lying on
ground. The observations were also made when one bag free falls
from conveyer belt height to the Poly woven bag at the end of
line.
[0060] The number of ruptures at the volume corners of the bags
were counted, and divided by the number of total bags to determine
the defect rates shown below:
TABLE-US-00001 TABLE 1 Example 1 Comparative Pouch A Comparative
Pouch B Defect rate 0.7% 1.9% 1.8% in %
Example 2
[0061] The ability of the pouches of the invention to reduce
quality defects during shipping was also tested. Here, the pillow
pouches of FIGS. 1-2 were made in the same manner as described in
Example 1 and filled with a predetermined weight of (.about.1.55
kg) of a granular laundry detergent. The comparative pouches
according to FIG. 3 were also filled with the same amount of the
granular laundry detergent. The pouches were manually packed one on
top of the other in a container for shipment. After arrival at the
destination, the number of film punctures or loss scalings were
counted, and multipled by the number of total bags to determine the
defect rates show below:
TABLE-US-00002 TABLE 2 Example 1 Comparative Pouch A Defect rate in
ppm 0 2137
[0062] The pouches of the invention demonstrated reduced quality
defects during shipment in comparison to the standard pouches with
substantially 90.degree. angles volume corners.
[0063] One skilled in the art would understand that the minor
differences in the materials between the Example and the
comparative pouches would not significantly affect the results of
these tests. Given the unexpectedly significant reduction in
rupturing.
[0064] The dimensions and values disclosed herein are not to be
understood as being strictly limited to the exact numerical values
recited. Instead, unless otherwise specified, each such dimension
is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "40 mm" is intended to mean "about 40 mm."
[0065] All documents cited in the Detailed Description of the
Invention are, in relevant part, incorporated herein by reference;
the citation of any document is not to be construed as an admission
that it is prior art with respect to the present invention. To the
extent that any meaning or definition of a term in this document
conflicts with any meaning or definition of the same term in a
document incorporated by reference, the meaning or definition
assigned to that term in this document shall govern.
[0066] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this invention.
* * * * *