Note: Descriptions are shown in the official language in which they were submitted.
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ASSEMBLY OF WEBS HAVING STAGGERED EDGE FOLDS
FIELD OF THE INVENTION
This invention is related to folded webs, and more particularly to folded,
premoistened wipes having an edge fold.
BACKGROUND OF THE INVENTION
Premoistened wipes, or wet wipes, are well known in the art. For instance, it
is
well known to use premoistened wipes for cleaning, including general cleaning
of
surfaces as well as personal cleaning of various body parts. One well known
use for
premoistened wipes is in cleaning an infant when changing the infant's diaper.
Premoistened wipes are typically provided in a stacked configuration within a
covered container, such as tub-like container having a Iid. The wipes are
typically folded,
and can be withdrawn from the container in a one-at-a-time fashion, as needed.
One problem with such an awangement is that it can be difficult to grasp the
wipe
for removal from the container. The leading end edge of the wipe is relatively
thin, and
can be difficult to grasp. In addition, the leading end edge of the wipe tends
to resist
separation from the underlying portion of the wipe. This resistance can be
due, at least in
part, to adherence between portions of the wipe caused by the liquid
composition which
is used to moisten the substrate of the wipe. As a result, it can be difficult
to grasp and
remove a wipe from the container with one hand. One hand dispensing is
especially
desirable when changing an infant's diaper.
One way to reduce the difficulty in dispensing wet wipes is by introducing an
edge
fold adjacent the leading end edge of each wipe. The edge fold provides added
thickness
for grasping. However, such edge folds, when aligned vertically in a stack,
result in a
non-uniform stack thickness. A generally uniform stack thickness is desirable
in order to
simplify handling and packaging of the stack, and to provide an appealing
product
appearance.
Accordingly, it is an object of the present invention to provide an assembly
of
folded webs, such as folded premoistened wipes, which can be easily dispensed.
Another object of the present invention is to provide a generally uniform
thickness
stack of discrete, folded premoistened wipes which can be easily dispensed in
a one-at-a-
time fashion.
Another object of the present invention is to provide a stack of premoistened
wipes
having staggered edge folds.
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2
SUMMARY OF THE INVENTION
The present invention provides an assembly of discrete, folded webs disposed
one
next to another to form a stack. In one embodiment, an assembly of discrete,
folded
premoistened wipes is provided. The wipe substrate comprises a fibrous web,
and the
wipes are disposed one next to another to form a stack within a container. The
premoistened wipes can be non-interfolded in the stack.
Each web extends lengthwise from a first, leading end edge to a second,
trailing
end edge. Each web has an edge fold positioned adjacent to, and spaced from,
the first,
leading end edge to provide a web lip extending between the edge fold and the
first,
leading end edge of the web. The web lip provides a double thickness of the
web
adjacent to the leading end edge, and facilitates grasping of the web.
The positions of at least some of the edge folds are staggered in the stack,
so that
all of the edge folds are not aligned with each other. Staggering of the edge
folds reduces
variation in the thickness of the stack which would otherwise occur in the
absence of
staggering.
The positions of the edge folds are preferably staggered a distance at least
as great
as the spacing between the edge fold and the first, leading edge of the web.
The spacing
between the edge fold and the first, leading edge of the web is preferably
less than about
0.75 inch, more preferably less than about 0.5 inch, and in one embodiment is
between
about 0.15 inch and about 0.35 inch.
Each web can include a first panel fold generally parallel to the edge fold.
The first
panel fold is spaced from the edge fold to provide a first web panel extending
between the
first panel fold and the edge fold. A second web panel is joined to the first
web panel at
the first panel fold. Each web can also include a second panel fold and a
third web panel.
The third web panel is joined to the second web panel at the second panel
fold. The web
is folded at the first and second panel folds to provide the first, second,
and third web
panels in a Z-fold configuration. Alternatively, other fold configurations,
including but
not limited to C-folds and J-folds, can be used.
At least one web in the stack has spacing between the edge fold and the first
panel
fold which is different from the spacing between the edge fold and the first
panel fold on
one or more other webs in the stack. The spacing between the edge fold and the
first
panel fold can vary in a predetermined, repeating manner to provide staggering
of the
positions of the edge folds in predetermined, repeating manner within the
stack.
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3
A method is also provided for forming a stack of folded wipes having staggered
edge folds. The method includes the steps of providing at least two continuous
webs;
forming an edge fold on each continuous web; and forming a first panel fold on
each
continuous web, such that the spacing of the edge fold from the first panel
fold on at least
one of the continuous webs is different from the spacing of the edge fold from
the first
panel fold on at least one of the other continuous webs. The method also
includes the
step of forming discrete folded webs from each of the folded continuous webs,
and
stacking the discrete folded webs one on top of another to form a stack of the
discrete
folded webs having edge folds staggered within the stack.
In one embodiment, the method includes the steps of conveying at least three
continuous webs in three separate lanes, and providing a folding apparatus
corresponding
to each of the continuous webs. The three continuous webs are each positioned
differently relative to their respective folding apparatuses to provide three
folded
continuous webs having three different spacings of the edge fold from the
first panel fold.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and
distinctly claiming the present invention, it is believed the present
invention will be better
understood from the following description in conjunction with the accompanying
drawings in which:
Figure 1 is perspective illustration of a folded web having an edge fold.
Figure 2 is a cross-sectional schematic illustration of the stack of folded
webs in a
container, the illustration showing staggering of the edge folds in the stack
according to the present invention.
Figure 3 is a cross-sectional illustration taken along lines 3-3 in Figure 1
showing a
_ folded web having an edge fold which provides a web lip "folded under", and
the web folded to have first, second and third web panels in a Z-fold
configuration.
Figure 4 is a cross-sectional illustration of alternative embodiment of a
folded web
having an edge fold which provides a web lip overlying a portion of a first
web paael.
Figure 5 is a schematic illustration of a relatively wide parent web being
slit into
six generally equal width, continuous webs.
Figure 6 is a schematic illustration of the continuous webs of Figure 5 being
folded
simultaneously on separate folding pan assemblies positioned in six parallel
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4
lanes, and the folded continuous webs being stacked one on top of another to
form a portion of a stack of folded webs having staggered edge folds.
Figure 7 is enlarged schematic illustration of three folding pan assemblies
shown in
Figure 6 showing the lane-to-lane variation of the position of the continuous
webs with respect to the folding pan assemblies.
Figure 8 is a cross-sectional schematic view taken along lines 8-8 in Figure 6
showing an edge fold being formed on a continuous web upstream of folding
pan assemblies as the edge of the web is conveyed through a folding tunnel.
Figures 9A-C are enlarged schematic illustrations similar to the illustration
of
Figure 7, except that the edge folds are shown being formed by folding
blocks positioned along the folding pan assemblies at different locations, the
positions of the folding blocks on the folding pan assemblies varying from
lane-to-lane.
Figure 10 is a cross-sectional schematic illustration taken along lines 10-10
in
Figure 9A showing the cross-section of the folding block and an edge fold
formed after the path of the edge of the continuous web has been interrupted
by the folding block.
Figure 11 is a side view schematic illustration of a continuous web being
folded as
the web is conveyed over a folding pan assembly shown in Figure 6.
DETAILED DESCRIPTION OF THE INVENTION
The term "wipe" refers to an article comprising a substrate, such as a fibrous
substrate, and intended to be used for removal of a substance from a surface
or object
which . is animate or inanimate, or alternatively, application of a material
to a surface or
object which is animate or inanimate. "Wipes" include articles with fibrous
substrates
used for human or animal cleansing or wiping, including but not limited to
human
cleansing and wiping such as anal cleansing, perineal cleansing, genital
cleansing, and
face and hand cleansing. "Wipes" also include articles used for application of
substances
to the body, including but not limited to application of make-up, skin
conditioners,
ointments, and medications. "Wipes" further include such articles used for
cleaning or
grooming of pets. Additionally, "Wipes" include articles with fibrous
substrates used for
general cleansing of surfaces and objects, such as household kitchen and
bathroom
surfaces, eyeglasses, excercise and athletic equipment, automotive surfaces,
and the like.
The term "premoistened wipe" refers to a wipe which includes a substrate which
is
moistened, such as by impregnating the substrate with a liquid composition,
prior to use
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by the consumer. In particular, "premoistened wipes" refers to wipes having a
substrate
which is moistened prior to packaging, such as in a generally moisture
impervious
. container or wrapper.
Figure 1 provides a perspective view of a folded web 50 having an edge fold
60.
Figure 2 is a cross-sectional illustration of a stack 40 of folded webs 50 in
a container 20.
The container 20 includes a tub portion 22 and a lid 24 (shown cut away)
pivotably
joined to the tub portion 22, such as by a hinge mechanism. U.S. Patent
5,065,887 issued
Nov. 19, 1991 is incorporated herein by reference for the purpose of
disclosing a suitable
container 20.
The folded webs 50 are shown stacked vertically in the tub portion 22 in
Figure 2.
Figure 2 illustrates staggering of the edge folds 60 of the folded webs 50
according to the
present invention. Figure 3 shows a single folded web 50.
Alternatively, the wipes can be stacked and then packaged in a moisture
impervious wrapper, such as a foil or polymeric film wrapper, to provide a
refill package
for use in refilling the container 20.
The folded web 50 can comprise a woven or nonwoven web of natural fibers, or
mixtures of natural and synthetic fibers. Suitable natural fibers include but
are not
limited to cellulosic fibers, such as wood pulp fibers and cotton. Suitable
synthetic fibers
include fibers commonly used in textiles, including but not limited to
polyestep,
polypropylene, and rayon fibers.
Various forming methods can be used to form a fibrous web from which the
folded
web 50 is made. For instance, the web can be made by nonwoven dry forming
techniques, such as air-laying, or alternatively by wet laying, such as on a
papermaking
machine. Other nonwoven manufacturing techniques such as melt blown,
spunbonded,
needle punched, and spun laced methods may also be used.
The dry fibrous web can be an airiaid nonwoven web comprising a combination of
natural and synthetic fibers and a latex binder. In one embodiment, the
fibrous web can
comprise wood pulp fibers and polyester fibers, with a styrene butidiene resin
binder.
The dry fibrous web can be about 20-80 percent by weight wood pulp fibers, 20-
60
percent by weight polyester fibers, and about 10-25 percent by weight binder.
The folded web 50 can comprise a fibrous web substrate impregnated with a
liquid
composition to provide a premoistened wipe. The liquid composition can be
water based,
and can include a number of additional ingredients, including but not limited
to,
preservatives, cleansers, fragrances, and lotions. The dry, fibrous web, prior
to being
impregnated with the liquid composition, can have a thickness of between about
0.017
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6
and 0.060 inch and a basis weight of between about 20 and about 75 pounds per
2880
square feet.
In one embodiment, the liquid composition with which the fibrous web is
impregnated can be water based, and include a mild surfactant, an emollient,
fragrance
ingredients, and preservatives. The dry substrate can be saturated with about
2.5 to about
4.5 grams of the liquid composition per gram of the dry fibrous web.
A suitable dry fibrous web substrate impregnated with a liquid composition is
marketed by The Procter & Gamble Company as BABY FRESH brand baby wipes and
PAMPERS BABY FRESH brand baby wipes.
The following patents are incorporated herein by reference for their
disclosure of
fibrous substrates and liquid compositions with which substrates can be
moistened: U.S.
Patent 3,862,472 issued Jan 28, 1975; U.S. Patent 3,982,302 issued Sept. 28,
1976; U.S.
Patent 4,004,323 issued Jan. 25, 1977; U.S. Patent 4,057,669 issued Nov. 8,
1977; U.S.
Patent 4,097,965 issued July 4, 1978; U.S. Patent 4,176,427 issued Dec. 4,
1979; U.S.
Patent 4,130,915 issued Dec. 26, 1978; U.S. Patent 4,135,024 issued Jan. 16,
1979; U.S.
Patent 4,189,896 issued Feb. 26, 1980; U.S. Patent 4,296,161 issued Oct. 20,
1981; U.S.
Patent 4,309,469 issued Jan 25, 1982; U.S. Patent 4,419,403 issued Dec. 6,
1983; U.S.
Patent 4,682,942 issued July 28, 1987; U.S. Patent 4,732,797 issued March 22,
1988;
U.S. Patent 4,772,501 issued March 22, 1988; U.S. patent 4,904,524 issued Feb.
27,
1990; U.S. Patent 4,941,995 issued July 17, 1990; and U.S. Patents 4,637,859;
5,223,096;
5,240,562; 5,556,509; and 5,580,423.
Refernng to Figures 1-3, each folded web 50 extends lengthwise from a first,
leading end edge 52 to a second, trailing end edge 54. The folded webs 50 also
have side
edges 56 and 58 which extend lengthwise from the first leading end edge 52 to
the second
trailing end edge 54.
Each folded web 50 has an edge fold 60. The edge fold 60 is generally parallel
to
the end edge 52, and generally perpendicular to the side edges 56 and 58. The
edge fold
60 is positioned adjacent to, and spaced &om, the end edge 52 to provide a web
lip 62.
The web lip 62 extends between the edge fold 60 and the end edge 52.
The edge fold is the fold positioned closest to the first, leading end edge
52. The
edge fold provides a web lip 62 which has a length less than the length of an
adjacent
panel of the web. A "panel" is a portion of the web extending between two
folds, or
between a fold and an edge end. The spacing between the edge fold 60 and the
first,
leading end edge 52 is preferably less than about 0.75 inch, more preferably
less than
about 0.50 inch, and even more preferably between about 0.15 inch and about
0.35 inch.
The spacing between the edge fold 60 and the leading edge 52 can be about 0.25
inch.
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The positions of at least some of the edge folds 60 are staggered in the stack
40, as
shown in Figure 2, such that all of the edge folds 60 are not aligned with
each other.
Staggering of the edge folds 60 reduces the variation in the thickness T
(Figure 2) of the
stack which would otherwise occur in the absence of staggering. In Figure 2,
the edge
folds 60 are staggered in a predetermined, repeating pattern. The edge folds
60 are
preferably staggered a distance at least as great as the spacing between the
edge fold 60
and the first end edge 52 so that portions of the web lips 62 are not in
overlying
alignment.
Referring to Figures 1 and 3, each folded web 50 can include a first panel
fold 70
which is generally parallel to the edge fold 60, and which is generally
perpendicular to
the side edges 56 and 58. The first panel fold 70 is spaced lengthwise from
the edge fold
60 to provide a first web panel 74 extending between the first panel fold 70
and the edge
fold 60.
The folded web 50 can also include a second panel fold 80, and second and
third
web panels 84 and 94. The second panel fold 80 is generally parallel to, and
spaced .
lengthwise from, the first panel fold 70. The second web panel 84 is joined to
the first
web panel 74 at the first panel fold 70, and extends between the .first panel
fold 70 and the
second panel fold 80.
The third web panel 94 is joined to the second web panel 84 at the second
panel
fold 80. The third web panel 94 extends between the second panel fold 80 and
the
second, trailing end edge 54. The web is folded at the first and second panel
folds 70 and
80 to provide the first, second, and third web panels 74, 84, and 94 in a Z-
fold
configuration, as best seen in Figure 3. In the Z-fold configuration, panel 74
is adjacent
to and, overlies a portion of panel 84, and panel 94 is adjacent to and
underlies a portion
of panel 84. Panel 74 extends from the fold 70 toward the center of panel 84,
and panel
94 extends from fold 80 toward the center of panel 84.
Referring to Figure 2, the folded webs 50 are non-interfolded in the stack 40,
so
that each folded web 50 can be dispensed from the container 20 without
disturbing the
adjacent, underlying folded web S0. Alternatively, it may be desirable in some
alternative embodiments to interfold adjacent folded webs 50. For instance, a
panel such
as pane! 94 on one folded web 50 could be interleaved between panels 74 and 84
of an
adjacent, underlying folded web.
The staggering of the edge folds 60 in the stack 40 can be provided by varying
the
spacing between the edge fold 60 and the first panel fold 70 among at least
some of the
folded webs 50 in the stack 40. Referring to Figure 2, the spacing between the
edge fold
60 and the first panel fold 70 varies in a predetermined, repeating pattern.
In Figure 2,
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s
there are six different values of the spacing between the edge fold 60 and the
first panel
fold 70, and the pattern repeats in groups of six folded webs 50. Such a group
of six
folded webs 50 is indicated by bracket 55 in Figure 2. The spacing between the
edge fold
60 and the first panel fold 70 is different for adjacent folded webs 50.
If the folded webs 50 are numbered 1 to 12, starting with the top folded web
50 in
Figure 2, the spacing between the edge fold 60 and the first panel fold 70 is
maximum for
the 1 st and 7th folded webs 50, and minimum for the 6th and 12th folded webs
50. Only
24 folded webs 50 are shown in Figure 2 for illustration purposes, but it will
be
understood that many more folded webs can and normally will be included in the
container 20.
In one nonlimiting, illustrative example, each folded web 50 can have an
unfolded
length of about 8.5 inches as measured lengthwise from end edge 52 to end edge
54.
Each of the folded webs 50 can have an edge fold 60 spaced about 0.25 inch
from the end
edge 52. For each of the folded webs, the spacing between the first panel fold
70 and the
second panel fold 80 can be about 4.5 inches, while the lengths of the first
and third
panels vary such that as the length of the first panel increases, the length
of the third panel
decreases. The spacing between the edge fold 60 and the first panel fold 70
can vary
from a maximum of about 2.0 inches for the 1 st folded web SO to a minimum of
about
0.75 inch for the 6th folded web 50, with the spacing between the second panel
fold 80
and the end edge 54 varying from about 1.5 inches {when the spacing between
the edge
fold 60 and the first panel fold 70 is maximum) to about 3.0 inches (when the
spacing
between the edge fold 60 and the first panel fold 70 is minimum).
While the stack 40 in Figure 2 has edge folds 60 which are staggered in a
pattern
that repeats in groups of six folded webs 50, it will be understood that the
edge folds 60
can be staggered in a pattern that repeats in groups of less than, or more
than, six folded
webs 50. Preferably, there are at least three different staggered positions of
the edge folds
60 in the stack 40, with the edge folds 60 staggered in a pattern that repeats
in groups of
at least three folded webs 50.
In one embodiment having three different staggered positions of the edge folds
60,
each folded web 50 can have an unfolded length of about 8.5 inches as measured
lengthwise from end edge 52 to end edge 54, and each folded web can have the
edge fold
60 spaced about 0.25 inch from the end edge 52. For each folded web 50, the
spacing
between the first panel fold 70 and the second panel fold 80 can be about 4.5
inches,
while the lengths of the first and third panels vary such that as the length
of the first panel
increases, the length of the third panel decreases. The spacing between the
edge fold 60
and the first panel fold 70 can vary from a maximum of about 2.0 inches for
the 1 st
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folded web 50 to a minimum of about 1.5 inch for the 3rd folded web 50, with
the
spacing between the second panel fold 80 and the end edge 54 varying from
about 1.5
. inches (when the spacing between the edge fold 60 and the first panel fold
70 is
maximum) to about 2.0 inches (when the spacing between the edge fold 60 and
the first
panel fold 70 is minimum).
Referring to Figure 2, an imaginary midplane of the stack 40 is shown as a
line
designated by the reference numeral 42. The midplane 42 is spaced equidistant
from the
first panel folds 70 and the second panel folds 80. By varying the spacing
between the
edge fold 60 and the first panel fold 70, the positions of the edge folds 60
are staggered
relative to the midplane 42. In the embodiment shown in Figure 2, all of the
edge folds
60 are located on the same side of the midplane 42. Alternatively, the folded
webs 50
could be oriented in the stack 40 such that edge folds 60 are located on both
sides of the
midplane 42.
In Figures 2 and 3, the edge fold 60 is made such that the web lip 62 is
"folded
under" to be positioned between portions of the first and second web panels 74
and 84.
Folding the web lip 62 under can provide the advantage that the web lip 62 is
trapped
between the first and second panels 74 and 84, thereby preventing unfolding of
the edge
fold 60. Alternatively, the edge fold 60 can be made such that the web lip 62
overlies a
portion of the first web panel 74, as shown in Figure 4.
The stack 40 of folded webs having staggered edge folds 60 can be provided by
hand folding and hand stacking. The webs can be individually hand folded to
have
varying spacing between the edge fold 60 and the panel fold 70, and then hand
stacked to
provide staggering of the edge folds 60 in a predetermined, repeating pattern.
However,
hand folding and stacking is generally expensive and time consuming.
Figures 5, 6, 7, and 8 illustrate a method for forming a stack 40 of folded
webs
having staggered edge folds 60. Figure 5 shows a continuous parent web 148.
The
continuous parent web 148 comprises the dry fibrous substrate from which the
folded
webs 50 are formed. The parent web 148 can have a width W of about 51 inches,
and is
unwound from a supply roll and slit into six continuous webs designated 150A-
150F in
Figure 5.
The parent web 148 can be slit by rotating knifes designated 110 in Figure 5.
In
Figure 5, the parent web 148 and the continuous webs 150A-150F are conveyed
generally
horizontally. The liquid composition with which the dry fibrous web is
impregnated can
be applied to each of the continuous webs 150A-150F as the continuous webs are
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conveyed generally horizontally. The liquid composition can be delivered to
the webs
150A-F by any suitable method, such as by coating the webs with a lotionizing
bar 120
having orifices through which a liquid composition under pressure is delivered
to a
surface of the webs. Alternatively, the webs can be sprayed or immersed in the
liquid
composition.
In Figure 6, the continuous webs 150A-150F are shown being conveyed generally
vertically. The edges 152 and 154 of the continuous webs 150A-150F are shown
in
Figures 5 and 6. The edges 152 and 154 correspond to the first leading end
edges 52 and
the second, trailing end edges 54, respectively, of the finished, folded webs
50. The
folding of the webs 1 SOA-F takes place simultaneously, along six parallel
lanes.
In Figure 6, each of the continuous webs 150A-F is first edge folded adjacent
to
edge 152 by directing the edges of the continuous webs 150A-F through folding
tunnels
200. Figure 8 shows a cross-sectional illustration of an edge fold 160 being
shaped on
the continuous web 150A by the folding tunnel 200. The folding tunnel 200 has
a
converging tunnel section 210 which turns the edge 152, thereby forming an
edge fold
160 on the continuous web 150A adjacent to the edge 152. The edge fold 160 on
a
continuous web 150 corresponds to the edge fold 160 on the folded web 50.
The continuous webs 150A-F are then each conveyed over a folding pan assembly.
In Figure 6, the folding pan assemblies are designated 300A-F. Each folding
pan
assembly includes a relatively smaller, triangular shaped folding pan 310 and
a relatively
larger, triangular shaped folding pan 320 spaced from the folding pan 310 by a
gap 330.
The folding pan 320 has a tip edge 325 which appears as a point in Figure 6.
Such
folding pan assemblies are known in the art. Below the folding pan assemblies
300A-F
the continuous webs 150A-F are guided between rollers 410 and 420. The
continuous
webs then pass through a nip formed by nip rollers 430 and 440.
The continuous webs 150A-F are driven by the nip rollers 430 and 440 to be
conveyed over the folding pan assemblies 300A-F. The folding of continuous web
150A
will be described with reference to Figures 6 and Figure 11. Figure 11 is a
side view,
schematic illustration showing the continuous web 150A being folded as it is
conveyed
over the folding pan assembly 300A. As the continuous webs 150A-F are conveyed
over
the folding pan assemblies 300A-F, the folding pan assemblies impart two folds
to the
continuous webs 150A-F.
One of the folds, designated 170 in Figure 11, corresponds to the first panel
fold
70. Fold 170 is imparted to web 150A as a portion of the continuous web is
drawn inta
the gap 330 between the pans 310 and 320. The fold 170 is initiated as the web
is
conveyed over the leading edges (upper edges in Figure 6) of the folding pans
310 and
and the first panel fold 70
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320 and drawn into the gap 330. As shown in Figure 11, the web is
progressively drawn
into the gap 330 as the web is conveyed from the top of the folding pan
assembly to the
bottom of the folding pan assembly.
The other fold, designated fold I80, corresponds to the second panel fold 80.
The
fold 180 is imparted to the continuous web as the continuous web passes over
the tip edge
32S of the folding pan 320.
The continuous webs 1 SOA-F are generally flat and inclined slightly to the
plane of
Figure 6 upstream of the folding pan assemblies 300A-F. The folded, continuous
webs
1 SOA-F are oriented at about a 90 degree angle with respect to the plane of
Figure 6 as
they leave the bottom of the folding pan assemblies and are conveyed between
rollers
4I0, 420 and driven between nip rollers 430 and 440. Accordingly, the folded
continuous
webs 1 SOA-F are viewed edgewise below the folding pan assemblies in Figure 6.
The six
folded, continuous webs 1 SOA-F are then conveyed around turning rolls 460 and
conveyed, one of top of another to provide group of six folded continuous webs
1 SOA-F.
The group is designated S40 in Figure 6.
The group S40 of continuous webs 1 SO can be cut at predetermined intervals at
a
downstream cutting station (not shown) to form separate, six count stacks of
discrete,
folded webs S0. Each of the folded webs SO in the six count stack corresponds
to one of
the six continuous webs 1 SOA-F. Multiple six count stacks of the discrete
folded webs SO
can then be combined, one on top of the other, to provide the stack 40 shown
in Figure 2.
In Figure 2, only four six count stacks are shown forming the stack 40, but it
will
be understood that many more six count stacks (e.g. I6 six count stacks for a
total of 96
folded webs SO) will normally be combined in a container 20. The stack 40 can
be loaded
into the container 20 at a packing station, not shown.
The spacing between the edge folds 160 (provided by the folding tunnels 200)
and
the folds 170 (provided by the folding pan assemblies) is varied, lane to
lane, from one
continuous web to the next (e.g. from continuous web 1 SOA to continuous web 1
SOB) to
provide staggered edge folds 60 according to the present invention. The
spacing between
the edge folds 160 and the folds 170 is varied by varying the position of the
continuous
webs with respect to the folding pan assemblies. The continuous webs can be
shifted
laterally by diB'erent amounts, from lane to lane, in order to vary the
position of the
continuous webs relative to the folding pan assemblies. Alternatively, the
folding pan
assemblies can be shifted laterally by different amounts, from lane to lane,
in order to
vary the position of the webs relative to the folding pan assemblies.
Referring to Figure 7, continuous web 1 SOA is conveyed over folding pan
assembly 300A such that the edge fold 160 is initially spaced a distance 360A
from the
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gap 330 in the folding pan assembly 300A. Continuous web 150B is conveyed over
folding pan assembly 300B such that the edge fold 160 on continuous web 150B
is
initially spaced a distance 360B from the gap 330 in the folding pan assembly
300B.
Continuous web 150C is conveyed over folding pan assembly 300C such that the
edge
fold 160 on continuous web 150C is initially spaced a distance 360C from the
gap 330 in
the folding pan assembly 300C. The distance 360A is greater than the distance
360B, and
the distance 360B is greater than the distance 360C. Accordingly, the spacing
between
the edge fold 160 and the fold 170 on continuous web 150A will be greater than
the
spacing between the edge fold 160 and the fold 170 on continuous web 150B.
Similarly,
the spacing between the edge fold 160 and the fold 170 on continuous web 150B
will be
greater than the spacing between the edge fold 160 and the fold 170 on
continuous web
150C. Accordingly, in the group 540 shown in Figure 6, the positions of the
edge folds
160 in the group 540 will be staggered due to this difference in spacing.
For instance, the distance 360A can be at least about 0.25 inch greater than
the
distance 360B, and the distance 360B can be at least about 0.25 inch greater
than the .
distance 360C. In one embodiment, the distances 360A-C differ by about 0.25
inch.
Accordingly, the edge folds 60 in the end product folded webs 50 can be
staggered a
distance of about 0.25 inch.
The webs 150A-F can be individually guided so that each web is conveyed over
its
respective folding pan assembly to provide the desired variation in the
distances 360
between the edge 152 and the respective gap 330. One method of positioning the
webs
laterally (perpendicular to the direction of travel in Figure 6) is by
providing a pressure
against the web adjacent to one of the edges 152 or 154. For instance, if a
pressure is
applied to the web in a direction perpendicular to the web {toward the viewer
in Figure 6)
and adjacent to the edge 152, the web will tend to move to the right in Figure
6.
Alternatively, if a pressure is applied adjacent to the edge 154, the web will
move to the
left in Figure 6. One method of applying such pressures is by conveying the
web over a
steering roll (not shown). The steering roll can have a fixed first end and an
adj ustable
second end. The position of the second end of the steering roll relative to
the web can
adjusted (such as by moving the second end of the steering roll toward or away
from the
viewer in Figure 6), thereby varying the pressure that is applied to the web
across the
width of the web.
In Figures 6-8, the edge folds 160 are imparted to the continuous webs 150A-
150F,
prior to forming the folds 170 and 180. The continuous webs 150A-F are then
conveyed
over the folding pan assemblies to provide the folds 170 and 180 corresponding
to panel
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folds 70 and 80 on the finished folded webs S0. This configuration has the
potential
disadvantage that the fold 160 may accidentally become unfolded before the
other folds
170 and 180 are made.
Figures 9A-C and 10 illustrate an alternative method of forming the edge fold
160
and varying the spacing between the edge fold 160 and the fold 170 on adjacent
continuous webs, such as webs 1 SOA and 1 SOB. Figures 9A-C are enlarged
schematic
illustrations of the webs being conveyed over their respective folding pan
assemblies. In
Figures 9A-C, the edge fold 160 is shown being formed by folding blocks 600
positioned
along the folding pan assemblies 300A-C at different locations. Figure 10 is a
cross-
sectional illustration taken along lines 10-10 in Figure 9A showing an edge
fold 160 as
the edge 152 of a continuous web 150A is carried through a folding block 600.
Folding
block 600 has a generally cylindrical surface 610. The radius of the surface
610 helps
prevent tearing of the web as the web is conveyed past the folding block 600.
Prior to positioning the folding blocks 600 on the folding pan assemblies, the
webs
are positioned laterally(such as with the above mentioned steering rollers) to
provide the
desired position of the web relative to its respective folding pan assembly.
Refernng to
Figure 9A, the continuous web 150A is conveyed over folding pan assembly 300A
such
that the web edge 152 is initially spaced a distance 370A from the gap 330 in
the folding
pan assembly 300A. In Figure 9B, continuous web 1508 is conveyed over folding
pan
assembly 3008 such that the edge 152 on continuous web 1508 is initially
spaced a
distance 3708 from the gap 330 in the folding pan assembly 3008 (Figure 9B).
Referring to Figure 9C, continuous web 150C is conveyed over folding pan
assembly
300C such that the edge 152 on continuous web 1 SOC is initially spaced a
distance 370C
from the gap 330 in the folding pan assembly 300C. The distance 370A is
greater than
the distance 3708, and the distance 3708 is greater than the distance 370C.
Accordingly, the spacing between the edge 152 and the fold 170 on continuous
web
150A will be greater than the spacing between the edge I52 and the fold 170 on
continuous web 1 SOB, and the spacing between the edge 152 and the fold 170 on
continuous web 1508 will be greater than the spacing between the edge 152 and
the fold
170 on continuous web 1 SOC.
Once the positions of the webs with their respective folding pan assemblies
are
established to provide the desired distances 370, the folding blocks 600 are
positioned on
the folding pan assemblies. The folding blocks 600 are joined to the
respective folding
pans 310 at a position just upstream of the position at which the edge 152
would enter the
gap 330 if the folding blocks 600 where not present. Placement of the block in
such a
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position has been found to result in the formation of the edge fold 160.
Importantly, the
edge fold 160 is formed as the web is conveyed between the leading edge of the
folding
pan assembly and the folding block 600, just prior to the point where the edge
fold 160 is
drawn into the gap 330. As the edge fold 160 is drawn into the gap 330, the
edge 152 is
positioned between other portions of the web, as shown in Figure 10, thereby
minimizing
the chance of the edge fold becoming unfolded.
Without being bound by theory, it is believed that placing the folding block
600 in
such a position creates the edge fold 160 by interrupting the path of the
portion of the
web adjacent to the edge 152. It is believed this interruption of the path of
the edge 152
causes the edge 152 to curl toward the viewer in Figures 9A-C, resulting in
formation of
the edge fold 160.
In Figures 9A-C, the edge folds 160 are not imparted to the continuous webs
150A-
C until the continuous webs have been at least partially folded by the folding
pan
assemblies. In particular, the edge folds 160 are not formed until the fold
170 is initiated
in the gap 330.
The folding blocks 600 can be made from any suitable material, including but
not
limited to stainless steel and hard plastics.
It has been found that the folding blocks 600 can be positioned at different
locations along the folding pan assemblies to provide the edge fold 160, yet
the edge
folds 160 are spaced generally equally from the web edges 152 on each of the
continuous
webs 150A-F. The resulting web lip between the edge fold 160 and the web edge
152
will accordingly be generally the same size for each of the continuous webs.
However, the spacing between the edge folds 160 and the folds 170 will vary
(the
spacing varying in decreasing order from continuous web 150A to continuous web
150C
in Figures 9A-C) due to the differences in the distances 370A-C. The fold 170
is initiated
as the web first enters the gap 330 at the leading edge of the folding pan
assembly.
Therefore, the spacing between the edge fold 160 and the fold 170 increases as
the
spacing 370 between the edge 152 and the gap 330 increases.
While particular embodiments of the present invention have been illustrated
and
described, various changes and modifications can be made without departing
from the
spirit and scope of the invention. It is intended to cover, in the appended
claims, all such
modifications and intended uses.
