Note: Descriptions are shown in the official language in which they were submitted.
21~I897
TITLE: SANITARY ABSORBENT ARTICL~ WITH AN ADHE~ IVE
POSITIONING SYSTEM COVERED BY R~T ~CE STRIPS
I.INRED TO ONE A~JO~ K h~~ AND APPARAl'US
FOR PACRAGIN~ THE ABSORBENT ARTICLE
FIELD OF THE 1NVL~1ON
The present invention relates to the art of
manufacturing structures for absorbing body exudate and,
more particularly, to a disposable sanitary absorbent
article with a quick-remove protective layer shielding the
adhesive securement system of the absorbent article when
the latter is not in use. The invention also extends to
a method and apparatus for folding the absorbent article.
P~ ROUND OF THE lNv~..lON
Disposable absorbent articles, such as sanitary
napkins, are maintained against the perineal region of the
wearer by adhesively securing the sanitary napkin to the
crotch portion of the undergarment. The adhesive
securement system usually comprises a plurality of
adhesive zones distributed on the barrier layer which
create a bond with the undergarment material to maintain
the sanitary napkin in place in spite o~ movements and
compression forces acting on it particularly when the
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"~ wearer is walking or otherwise shifting the position of
her legs.
In the past recent years, the industry has designed
sanitary napkins with laterally projecting positioning
tabs intended to be folded about respective edges of the
undergarment for more positively holding the sanitary
napkin in place. To develop an effective retention force,
the positioning tabs are adhesively secured to the garment
facing surface of the underpants. Thus, the sanitary
napkin has at least three adhesive zones namely one zone
on the main body of the sanitary napkin and two additional
adhesive zones one on each positioning tab. To protect
the adhesive system while the sanitary napkin is not in
use, the manufacturer typically applies a protective layer
over each adhesive zone, which is peeled-off by the user
immediately prior the placement of the sanitary napkin on
the undergarment. The protective layer is generally made
of paper having an outer non-stick surface. A
particularly useful material is a semi-bleached Kraft
paper, the adhesive contacting side of which has been
silicone-treated to provide easy release properties.
Some difficulty arises with thi~ approach in that a
plurality of ~eparate protective layers are necessary, one
for each adhesive zone. Thu~, the user is required to
2I51897
~ separately peel-off several paper strips to expose the
entire adhesive system, which is time-consuming and
annoying. In addition, the paper strips must be peeled-
off with some degree of care to avoid the adhesive zones
from contacting each other or the barrier layer of the
~anitary napkin. If such an accident occurs, the product
can be rendered useless especially if the exposed adhesive
on a positioning tab contacts the adhesive zone on the
main body of the sanitary napkin.
OBJECT8 AND 8U~ARY OF THE INV~NTIQN
An object of the invention is a sanitary absorbent
article with a protective layer for the adhesive system
that can be quickly and conveniently removed.
Another object of the invention is a novel method and
apparatus for folding the sanitary article to ease
packaging.
As embodied and broadly described herein, the
invention provides a disposable sanitary absorbent article
for adhesive securement to an undergarment of a wearer,
said absorbent article comprising:
- a main body that includes:
a) a body contacting liquid-pervious cover layer;
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b) an absorbent core underneath said body contacting
liquid-pervious cover layer, said absorbent core
being in liquid-communicative relationship with said
cover layer, whereby liquid discharged on said cover
layer i9 transferred to eaid absorbent core for
storage therein;
c) a liquid-impervious barrier layer beneath said
absorbent core, said barrier layer preventing liquid
entrapped in said absorbent core from egressing said
main body from a garment facing surface thereof;
- a positioning tab laterally projecting from each
longitudinal side of said main body, each said positioning
tab being flexible and being capable of being folded about
a respective edge of an undergarment on which said
absorbent article is to be installed;
- an adhesive securement system for releasably retaining
said absorbent article to the undergarment, said adhesive
securement system including;
a) a first adhesive zone on a garment facing surface
of said main body;
b) a second adhesive zone on a garment facing surface
of one of said positioning tab~;
c) a third adhesive zone on a garment facing surface
of the other one of said positioning tabs, said
first, second and third adhesive zones being in a
spaced apart relationship;
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d) a peelable protective layer covering said adhesive
zones, said peelable protective layer including:
i) a primary release strip extending generally
longitudinally on said main body and being
s releasably attached to said first adhesive zone;
ii) a secondary release strip extending
generally transversely on said main body and
being releasably attached to said second and
third adhesive zones, said release strips
crossing each other.
In a preferred embodiment, the sanitary absorbent
article, such as a sanitary napkin, includes a primary
release strip extending longitudinally on the main body of
the sanitary napkin to cover the first adhesive zone that
in use bonds with the body facing surface of the
undergarment. Most preferably, the first adhesive zone is
formed by a pair of longitudinally extending adhesive
bands running almost the entire length of the main body.
The second~ry release strip is mounted transversely on the
sanitary napkin, overlying the primary strip to cover the
adhesive zones on the positioning tabs with its end
portions. By pulling the primary release strip, the
secondary release strip is removed as well to expose the
entire adhesive system in a ~ingle peel-off stroke. A
reverse arrangement where the primary release strip
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overlays the secondary release strip i8 also possible.
Under this embodiment the user needs to pull on the
secondary strip to effect the removal of the entire
protective layer.
To prevent the central portion of the uppermost
release strip (the point of reference for "uppermostn is
a sanitary napkin with a barrier layer on top) from
sagging or bowing, it is proposed to adhesively secure
both release strips at their crossing point.
The application of the protective layer during the
manufacture of the sanitary napkin is a two-step
operation. In a most preferred embodiment, the sanitary
napkins are directed by a coll~eyor system to a first
processing station that deposits a primary release strip
on each sanitary napkin. At this point the sanitary
napkins have not yet been cut into individual products and
they are still serially united, thus forming a continuous
web. The fir~t processing station comprises a vacuum roll
immediately above the conveyor belt, which is supplied
with release strip material in continuous form drawn from
a supply reel. An adhesive applicator deposits hot-melt
glue on the run of release strip material between the
supply reel and the vacuum roll. The adhesive-coated
release strip material is clamped against the
21~I897
~circumference of the vacuum roll and transversely cut
thereon in discrete primary release strips. The
continuing rotation of the vacuum roll which is timed with
the linear speed of the conveyor belt deposits the release
strips on the sanitary napkins. The hot-melt adhesive is
transferred to the barrier layer of each sanitary napkin
and permanently bonds with it 80 when the release strip is
peeled-off the adhesive will remain on the barrier layer.
10The secondary release strip is applied at a second
processing station by the intermediary of a roll that
transfers a continuous band of adhesive-coated release
strip material to the web containing the sanitary napkins.
Note that in addition to depositing on the release strip
material the adhe~ive that will be transferred to the
positioning tabs, an additional adhesive site is created
to bond the secondary release strip to the underlying
primary release strip at their crossing point. Contrary
to the process taking place at the first processing
station no cutting of the release strip material takes
place on the roll. The continuous band of release
material is separated in individual release strips later
at a die cutting station where the sanitary napkins web is
cut in individual products.
2lsl897
To manufacture sanitary napkin with a protective
layer where the primary release strip overlays the
secondary release strip the same procedure is observed
with the exception that the order of deposition of the
strips is reversed, i.e. the secondary strip is applied
first followed by the primary release strip.
As embodied and broadly described herein the
invention also provides a method for folding a sanitary
lo absorbent article which includes a release strip covering
an adhesive zone of said sanitary absorbent article, said
release strip manifesting a shape retention capability
when creased, said method comprising the steps of:
- folding said sanitary absorbent article; and
- forming a crease in said release strip at a fold
region of said sanitary article, whereby said release
strip assists said sanitary absorbent article in
maintaining a folded condition by resisting efforts
tending to uncrease said release strip.
In this specification the expression "folding said
sanitary absorbent articlen should be construed to mean
the action of placing one part of the sanitary absorbent
article over another part of it, without any limit as to
relative size or dimensions of the parts. Thus, folding
the sanitary absorbent article in half, or folding only a
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~ small part, such as a positioning tab, over the main body
would fall in the ambit of thi~ wording.
The expression "shape retention capability" refers to
a material that after being deformed has a tendency to
remain in the deformed condition.
The expression "folded condition" used subsequently
in the text designates the relationship between parts of
the sanitary napkin brought by folding movement one over
the other and forming an angle between them that is
~ubstantially less than 180.
The folding operation broadly defined above is
particularly useful during the packaging operation of the
sanitary napkins when they are folded for insertion in
di~posable pouches. The packaging operation is a delicate
procedure because the sanitary napkins once folded have
immediate tendency to unfold which makes the insertion of
the product in the pouch difficult. Creasing the release
strip overcomes this potential difficulty because the
release strip material is permanently deformed and it will
then oppose the natural tendency of the sanitary napkin to
unfold. Thus, the sanitary napkin is maintained in a
folded condition for a period sufficiently long to
complete the packaging operation.
2l~l897
~- It should be noted that the folding and the creasing
operations can be effected at different instants in time
or simultaneously. In the former ca~e, the folding
operation i8 performed first, followed be the creasing
operation that permanently deforms the release strip.
In a most preferred embodiment, the folding operation
begins by laying one positioning tab over the body
contacting liquid-pervious cover layer. A convenient way
of folding the positioning tabs is by directing a jet of
compressed air at the sanitary napkin to bring the
positioning tab in a folded condition. While the air jet
is active, the sanitary napkin passes under a creasing
roller that creates enough pressure to form a sharp ridge
in the release strip. Since the release strip is united
to the folded positioning tab and to the remaining part of
the sanitary napkin, it will keep the positioning tab
folded without any noticeable manifestation of shape
recovery over several hours. In practice, it suffices to
maintain the positioning tab folded for a time long enough
to enable the packaging station to insert the sanitary
napkin in the individual pouch. Given the high speed of
the machines available today, this time frame is short, in
the range of a fraction of a second to a few seconds at
most.
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2lsl897
The ability of the release strip to resist the
natural tendency of the sanitary napkin to unfold depends
primarily upon two factors. First, the release strip
material must have a shape retention property 80 once
creased it will not immediately return to its original
configuration. Second, the material should be
sufficiently rigid. The silicone coated paper material
that is typically used in the prior art for manufacturing
release strips satisfies these requirements. It works
particularly well for maintaining the positioning tabs on
the sanitary napkin folded against the cover layer. It
should be noted that the positioning tabs are thin
structures and the force required to keep them in a folded
condition is small. Thus, a thin release strip material
is sufficient. One could also envisage folding the
sanitary napkin at a much thicker region, such as folding
it in half that requires to bend the entire absorbent
sy~tem sharply. For such applications, thicker release
strip material will be required to maintain the sanitary
napkin in a folded condition since it now manifests much
higher resiliency.
As embodied and broadly described herein the
invention al~o provides a method of folding a sanitary
absorbent article that includes:
2l5l897
~ a) at least one tab projecting from a main body of
said sanitary absorbent article; and
b) a release strip covering an adhesive zone of said
sanitary absorbent article, said release strip extending
over a juncture between said tab and said main body and
manifesting a shape retention capability when bent, said
method comprising the step of folding said tab over said
main body at said juncture to a degree sufficient for
causing said release strip to acquire a la~ting folded
condition, whereby said release strip resists efforts
tending to unfold said tab.
The expression "lasting folded condition" means that
the release strip will not readily return to its original
configuration. Two specific possibilities fall in the
ambit of this expression. First, the release strip has
very little memory and it remains permanently folded.
Second, the release strip is capable of shape recovery,
however, the shape recovery is slow. Thus, when the force
that bends the release strip is discontinued the release
strip remains folded for an appreciable amount of time and
does not immediately spring back to its original (non
folded) condition. For example, the "lasting folded
condition" can be acquired by creasing the relea~e strip.
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2l~l897
As embodied and broadly described herein, the
invention also provides an apparatus for folding a
sanitary absorbent article which includes a release strip
covering an adhesive zone of said sanitary absorbent
article, said release strip manifesting a shape retention
capability when creased, said apparatus comprising:
- means for folding said sanitary absorbent article;
and
- means for forming a crease in said release strip at
a fold region of said sanitary absorbent article, whereby
said release strip assists said sanitary absorbent article
in maintaining a folded condition by resisting efforts
tending to uncrease said release strip.
In a most preferred embodiment, the means for folding
the sanitary absorbent article and the means for creasing
are different devices, such as the air jet and the
creasing roll described earlier. However, one may
envisage combining the folding and the creasing functions
together 80 these operations are performed simultaneously.
A possible example is a roller that would fold the
sanitary absorbent article and crease the resilient strip
at the same time.
~15I ~97
As embodied and broadly described herein the
invention also provides an apparatus for folding a
sanitary absorbent article that includes:
- at least one tab projecting from a main body of
said sanitary absorbent article; and
- a release strip covering an adhesive zone of said
sanitary absorbent article, said release strip extending
over a juncture between said tab and said main body and
manifesting a shape retention capability when bent, said
apparatus comprising means for folding said tab over said
main body at said juncture to a degree sufficient for
causing said release strip to acquire a lasting folded
condition, whereby said release strip resists efforts
tending to unfold said tab.
As embodied and broadly described herein, the
invention also provides a sanitary absorbent article
including an adhesive zone for securing said sanitary
absorbent article to an undergarment of a wearer and a
release strip covering said adhesive zone, said s'anitary
absorbent article being in a folded condition and said
release strip including a crease in a folded region of
said sanitary absorbent article, said release strip
manifesting a shape retention capability when creased,
whereby said release strip assists said sanitary absorbent
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21S1897
article in maintaining a folded condition by resisting
efforts tending to uncrease said release strip.
As embodied and broadly described herein, the
invention also provides a sanitary absorbent article
including:
a) at least one tab extending from a main body of
said sanitary absorbent article, said tab being folded
over said main body; and
b) a release strip covering an adhesive zone of said
sanitary absorbent article, said release strip extending
over a juncture between said tab and said main body, said
release strip being folded at said juncture and
manifesting a sufficient shape retention capability for
resisting efforts tending to unfold said tab.
BRIEF DESCRIPTION OF THF DRAWINGS
- Figure 1 is a perspective view of a sanitary napkin
in accordance with the invention featuring a quick-remove
protective layer for the adhesive system;
- Figure 2 i~ a top plan view of the sanitary napkin
shown in Figure 1, the protective layer being shown partly
peeled-off;
2151897
- Figure 3 is a perspective view of a processing
station for applying to sanitary napkins a first component
of the protective layer;
- Figure 3A is a schematical cross-sectional view of
a vacuum roll from the processing station shown in Figure
3;
- Figure 4 is a perspective view of a second
processing station for applying to the sanitary napkins a
second component of the protective layer;
- Figure 5 is a side elevational schematic view of an
apparatus for folding a tab of the sanitary napkins during
a packaging operation;
- Figure 6 is a schematical side elevational view of
a device for inverting the sanitary napkins during the
packaging operation;
- 20
- Figure 7 is a side elevational schematic view
illustrating the sanitary napkins when released from the
inverting device;
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- Figure 8 i9 a per~pective view of the device for
completing the folding operation of the sanitary napkin;
and
- Figure 9 is a perspective view of a sanitary napkin
constructed in accordance with a variant.
DESCRIPTION OF A PREFERRED EMBODIMENT
The present invention provides a sanitary absorbent
article, such as a sanitary napkin, having a peelable
protective layer that is releasably attached to the
adhesive system, which can be removed quickly and
conveniently as a single piece. With reference to the
annexed drawings, the sanitary napkin designated
comprehensively by the reference numeral 10 comprises a
liquid-permeable cover layer 12 overlaying an absorbent
core (not shown in the drawings). The absorbent core
preferably includes ~phagnum moss material and it is
comparatively thin, i.e., having a few millimeters in
thickness. The cover layer is highly porous to allow
liquid delivered on the surface of the sanitary napkin to
rapidly reach the absorbent core. Underneath the
absorbent core is provided a barrier layer 14 made of
liquid-impervious material, such as polyethylene, to
prevent liquid entrapped in the absorbent core from
2I51897
~ egressing the sanitary napkin and staining the wearer's
undergarment. The cover layer 12 and the barrier layer 14
are joined along their marginal portions to form an
enclosure that maintains the absorbent layer with the
absorbent core captive. The joint may be made by means of
adhesives, heat-bond, mechanical crimping or any other
suitable process. Note that in Figures 1 and 2 the
sanitary napkin 10 is shown in an inverted position; its
normal position of use being such that the cover layer 12
is on top and the barrier layer }4 is on the bottom.
To stabilize the sanitary napkin on the wearer~s
underpants, a pair of laterally projecting positioning
tabs 16 and 18 are provided on each longitudinal side edge
of the sanitary napkin. The positioning tabs 16 and 18
are dual-layer laminated structures. The upper layer i9
formed by an extension of the cover 12 and the lower layer
by an extension of the barrier layer 14. The positioning
tabs 16 and 18 are flexible 80 they can be folded about
the edges of the undergarment.
To secure the sanitary napkin 10 against the
undergarment of the wearer, an adhesive securement system
is provided comprising a pair of adhesive zones 20 and 22
on the barrier layer of the main body of the sanitary
napkin. The adhesive zones 20 and 22 are in the form of
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2l~l897
elongated bands slight~ly spaced apart from one another.
The bands extend almost the entire length of the sanitary
napkin. In addition, the adhesive securement system
comprises adhesive zones 24 and 26 on the positioning tabs
portions of the barrier layer 14.
To protect the adhesive securement system while the
sanitary napkin is not used, a peelable protective layer
28 covers the adhesive zones. The protective layer
comprises a primary release strip 30 that extends
longitudinally on the sanitary napkin and has a width
sufficient to span the adhesive bands 20 and 22. To
shield the adhesive zones 24 and 26 on the positioning
tabs, a secondary release strip 32 is placed transversely
on the sanitary napkin, thus crossing the primary strip
30.
The preferred material for making the release strips
30 and 32 is bleached Kraft paper coated with silicone on
the adhesive facing surface to provide a non-sticky side.
The release paper material available from AKROSIL (a
division of International Paper) having a basis weight of
25 pounds per ream with a silicone coat of 2.8 pounds per
ream has been found satisfactory.
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2l5l~97
~ To prevent the central portion of the secondary strip
32 from sagging or bowing when the sanitary napkin is
handled, it i9 adhered to the back surface of the primary
strip 30 by means of an adhesive zone 34. This is a very
weak bond since one of the surfaces is a silicone coating,
however, it has been found sufficient for keeping the
secondary strip 32 from freely moving.
To install the sanitary napkin 10, it suffices to
peel-off the protective layer 28. This is done by
removing first the main release strip 30. By doing so,
the secondary release strip 32 is also removed. As a
result, the entire adhesive system is exposed in a single
peel-off ~troke which is quick and convenient for the
user.
The sanitary napkin 10 is manufactured by a
continuous process during which the various layers forming
the absorbent structure are laid on one another and sealed
to form a continuous web 40 of sanitary napkins serially
joined together. The final step of the manufacturing
process, immediately prior the packaging, is to die cut
the web in discrete products. TypicalIy, the web is
formed by first placing on a conveyor belt a continuous
band of cover layer material. Subsequently, transfer
layers overlaid by absorbent cores are deposited in a
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2lsl897
spaced apart relationship on the band of cover layer
material. Finally, a band of barrier layer material is
placed immediately on top of the absorbent cores and
sealed to the underlying cover layer band to encapsulate
S the absorbent Qtructures fully. The web iB then directed
to the processing station shown in Figure 3 provided to
deposit on the sanitary napkin blanks 36 (by "blanks" is
meant sanitary napkins that are integrally joined to one
another to form the web 40) primary release strips 30.
The processing station comprises a vacuum roll provided
with perforations on its circumferential surface through
which a pressure differential can be established. The
vacuum is effective only on the perforations that reside
within the sector 42 having an annular extent of about
120. The sector 42 creates an active suction region that
causes a web to adhere to the surface of the roll 41 as it
travels through that region. Outside the boundaries of
the active suction region, the web is no longer retained
to the roll 41.
Figure 3A is a vertical cross-sectional view of the
roll 41 and illustrates how the active suction region is
implemented. The roll 41 is a hollow structure in which
is mounted a stationary manifold 44 connected by a conduit
46 to a source of vacuum (not shown in the drawings). The
manifold 44 has an apertured convex wall 48 closely spaced
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~ from the periphery of the drum 41 to establish a fluid
communicative relationship between the source of vacuum
and the perforations on the drum 41 that reside in the
active region 42.
On top of the vacuum roll 41 is mounted a cutting
roll SO that rotates at the same linear speed as the
vacuum roll 41. The cutting roll 50 includes a plurality
of axially extending cutting blades 52 that are
circumferentially spaced by a distance corresponding to
the width of a primary release strip 30.
The release strip material i~ supplied to the nip
between the cutting roll 50 and the vacuum roll 41 as a
continuous web 54 drawn from a supply reel (not shown).
The web of release strip material is cut by the action of
the cutting roller 50 in discrete primary release strips
30 that are retained against the vacuum roll 41 as they
-enter the active suction region. Thus, the discrete
primary release strips 30 are firmly retained against the
vacuum roll 41 until they pass beyond the lower boundary
of the active vacuum region where they are deposited on
individual sanitary napkin blanks 36.
The primary release strips 30 provide a convenient
vehicle for depositing the adhesive material forming the
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bands 20 and 22 on the sanitary napkin blanks 36. At this
end, adhesive is applied on the silicone treated surface
of the web 54 of release material between the supply reel
and the nip of the rollers 50 and 41 by any suitable
device such as a sprayer or a slot coater. The adhesive
is a hot-melt glue well-known to those skilled in the art.
H.B Fuller Canada is a supplier of a variety of hot-melt
adhesive particularly well-suited for use on sanitary
napkins or other sanitary absorbent articles. The
adhesive is applied on the web 54 according to a pattern
to suit the desired disposition of adhesive zones on the
final product. In the example shown, the adhesive i~
deposited as transversely spaced strips to form the
adhesive bands 20 and 22.
In use, the web 54 is adhesive coated then cut into
successive primary release strip~ 30 and finally deposited
on respective sanitary napkin blanks 36. During the
application of each primary release strip 30 on the
respective sanitary napkin blank the adhesive bands are
transferred to the barrier layer and they permanently
stick to it.
Note that the vacuum roll 41 is driven at a different
linear speed than the sanitary napkins blanks 36 to enable
the individual release strips 30, which abut one another,
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~ to register with the respective blanks 36 that are in a
spaced apart relationship. At this end the vacuum roll 41
is operated stepwise rather than being rotated at a
continuous speed. At each angular increment the roll is
accelerated until its linear ~peed matche~ the speed of an
incoming blank. Thus, while the blank 36 and the vacuum
roll 41 are in contact with one another there is no slip
between them to allow proper transfer of the release strip
30. After the transfer is completed the vacuum roll slows
down for a short period of time before initiating a new
angular increment for the next blank 36.
After this operation is completed, the web 40 is
passed through a second processing station that applies
the secondary release strips 32. The release strip
material is supplied to the processing station as a
continuous web 56, adhesive coated at spaced intervals for
creating the adhesive zones 24, 26 and 34 and then pressed
against the sanitary napkin blanks 36, over the primary
release strips 30. The application is made by a roll 58
that has a linear speed corresponding to the speed of
travel of the web 40. Contrary to the first processing
station, no cutting takes place at the second processing
station and as a result, there is no need to use a vacuum
roll for holding discrete elements.
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`~ The next processing station, not shown in the
drawings, uses a die cutting apparatus that separates the
sanitary napkin blanks 36 from one another to form final
products. During the cutting operation, the continuous
strip 56 of release material is cut between adjacent
products.
This completes the manufacture of the sanitary
napkins. The next operation performed on the production
line is the packaging process that consists of folding the
sanitary napkins 10 and then placing them in individual
pouches. Figure 5 is a schematical illustration of the
first processing station of the packaging section. The
processing station comprises a conveyor belt 60 that
travels in the direction of the arrow 62. Above the
conveyor belt 60 is provided a large suction casing 64
connected to a source of vacuum (not shown). The belt 60
has arrays 66 of perforations spaced from one another by
a distance corresponding to about twice the length of a
positioning tab. The perforations of a given array 66 are
designed to hold by suction on the undersurface of the
belt 60 a sanitary napkin by its main body and leave the
positioning tabs hanging. This feature allows one
positioning tab to be folded against the cover layer of
the ~anitary napkin as it will be described below.
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~- An air jet 68 generates a stream of compressed air
against the leading tab 18 and forces the tab to fold
against the cover layer of the sanitary napkin. While the
tab 18 is maintained in the folded condition by the
current of compressed air, it passes through a nip formed
by a creasing roll 70 and the surface of the conveyor belt
60. The roll 70 creates a significant amount of pressure
to form a sharp crease in the secondary release strip 32
at the fold region between the positioning tab 18 and the
main body of the sanitary napkin. Since the release strip
32 is attached to both the positioning tab 18 and the main
body of the sanitary napkin, when creased the release
strip, due to its inherent rigidity, will maintain the
positioning tab in the folded condition.
The next processing station of the packaging ~ection
i8 shown in Figures 6 and 7 and comprises an inverter
designed to flip the sanitary napkins upside down. In
other words, the sanitary napkins will be returned 80
their cover layers face up. The inverter is an endless
conveyor belt with projecting slats 72 that define
sanitary napkin holding pockets between them. The
conveyor belt 60 ends its horizontal run where the
conveyor belt of the inverter loops a roller 74 80 the
sanitary napkin holding pockets are wide open. When the
individual sanitary napkins 10 pass beyond the vacuum
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2l5l897
~ region created by the suction casing 64, they are released
from the conveyor belt 60 and enter respective holding
pockets of the inverter.
The sanitary napkins 10 travel horizontally on the
inverter until they reach a roller 76 that is looped by
the conveyor belt. At this point, the slats 72 are spread
apart 80 the individual sanitary napkins are free to
egress the pockets and fall on a third conveyor belt 78
that i8 similar to the conveyor belt 60 in that it
comprises arrays 80 of apertures passing under a suction
casing 82 to grip by the effect of vacuum the sanitary
napkins 10 by the main body. Figure 8 illustrates the
arrangement of the perforations of a single array 80. It
will be noted that the perforations are concentrated in
the central portion of the conveyor belt 78 80 that only
the central portion of the main body will be subjected to
vacuum. This allows the longitudinal extremities and the
positioning tabs to be folded as it will be de~cribed
20 later.
As the sanitary napkins 10 are discharged from the
inverter, they pas~ under a guide 84 who8e purpose is to
fold the positioning tab 16. The guide 84 is a curved
25 plate that converges toward the conveyor belt 78 to fold
the positioning tabs 16 progressively and also crease the
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` -
secondary release strip 32 at the juncture between the tab
16 and the main body of the napkin. The pressure exerted
on the sanitary napkin increases significantly when the
tail end of the guide 84 is reached which causes the
release strip 32 to crease which will hold the tab 16
folded until the packaging operation is completed.
It will be noted that the release tab 18 is unlikely
to unfold as the sanitary napkin passes between the
progressively narrowing passage of the guide 84 because
the tab 18 is maintained in a tightly folded condition by
the creased release strip 32.
The sanitary napkins 10 leaving the guide 84 are in
the form shown in Figure 8, with both of their flaps
folded against the body contacting cover layer. The next
step of the folding operation is to pass the sanitary
napkin through longitudinally extending guides 86 and 88
that gradually curve the longitudinal extremities of the
sanitary napkin 80 as to progressively fold them against
the cover layer. At this point, the pouch is formed
around the sanitary napkin 80 as to provide a protective
envelope to prevent contamination of the product during
shipping and storage. The method and the apparatus used
for forming the individual pouches will not be described
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2I51897
herein because they are well known in the industry and
they do not form part of the present invention.
In a possible variant, the order of placement of the
release strips 30 and 32 i9 reverged 90 the larger release
strip 30 i9 on top of the smaller release strip 32. This
embodiment i9 suitable for applications where it i9
desirable to effect removal of the entire peelable
protective layer by pulling on the strip that covers the
adhesive zones 24, 26 on the positioning tabs 16, 18,
respectively. To manufacture this variant, the process as
described earlier i9 followed except that the processing
station applying the secondary release strip 32 i9 placed
before the processing station that applies the primary
release strip 30.
In a further variant two smaller release strips,
covering the respective adhesive bands 20, 22 could be
substituted to the main release strip 30 for reducing the
amount of release strip material required to cover the
adhesive system. This embodiment is shown in Figure 9.
The smaller release strips that replace the single release
strip 30 are designated by the reference numerals 100 and
102. To manufacture this embodiment, two changes are
required. First, the cutting roll S0 i8 provided with
additional cutting blades 52 so the web 54 i9 severed into
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2151897
narrower strips. Second, the adhesive deposition pattern
on the web 56 iR modified 80 each secondary release ~trip
32 bonds with each one of the strips 100 and 102 at 104
and 106.
Application~ of the product, method and apparatus of
the present invention for sanitary and other health-care
uses can be accomplished by any sanitary protection,
incontinence, medical and absorbent methods and techniques
as are presently or perspectively known to those ~killed
in the art. Thus, it i~ intended that the present
application covers the modification~ and variations of
this invention provided that they come within the scope of
the appended claims and their equivalents.
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