. a ~ r . , u:m,- .~~t:~ t3:J '_ ~i:J: 3 1--3-~':~ : ~t ;~
:1-Mor-d5 0: 9 From-~:)-hEi~~~'VAI,GH CJ ~ ~514-~~54-i3i)o T-'3i P.05/25 F-i81
1
ABSORBENT p.RTICLFs AN17 METHOD AND APPAR~T'Q5
FOR M,P~N~'FACTURING SAD
FIELD 0: THE INS ~NT10I~1
The p-_ssenz i~:ver_tion relates to a sanitary absorbent article
such a sanitary napkin, incontinence pad and the like. More
particularly, tee invention rala*~es to a novel sanitary
absorbent article and to a component lays; thereof t=:at can be
prod~~ced with less wasta n,a~e=gal generated, and tc a method of
and apparatus far tre manufacture thereof, The irvencion also
extends to a me=hod and apparatus for manufactu=ing =he novel
absorbent a=ticle.
HACKGROIJND OF TF=E i'.~TVENTION
~_he technology surrounding absorbent ar~icles,
particularly sanitary ::apk_n9, has undergone several advances
is over the past two decades. One of these ad~rances was the
addit'_on of multi-functional flaps to 4he lcrg_tudi_nal sides cf
c'~e napkin. T~Ihen in use such fl ape are folded over the sides
of ~.he wearer' s undergar.~.:ent and recur ed ~=hereto . =hey thus
more firmly secure the napkin to the a~dergarment, pro~ridz an
~C i:_creased absorptive area for bodily exuda~es, and help prevent
t'-~.e urdergarwar_t from becoming sailed. The flap cot~.cezat has
generally men w=tr success in tr~a marketplace, and napkins with
flaps of various ccr_figuracions ar~d conformations are available
to she consumer.
25 Such sanitary absorbent article3 are erdirarily composed
of se~yeral layers of various materials affixed together to form
a laminated structure. '''hey are generally manuzactured in the
following manner: A laminated web comprised of the materials
forming each of the individual component layers of the final
3D article is provided. At least one layer of material, and mere
likely several, is continuous throughout the web. The wen is
.,rl~~'li~_ ~.,'1;~~
CA 02274129 1999-06-04 %
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2
then sealed at various points and severed to form discrete
articles.
Alternatively, although generally uncommon, each of the
individual component layers which make up the article could be
produced separately, through their severance from a continuous
sheet of material of which the layer is formed. These various
component layers could then be combined together (i.e.
laminated) to form the article.
In either method, the articles or the component layers
themselves (as the case may be) receive their shape as they are
severed from the laminated web or the continuous material,
respectively.
An example of a sanitary napkin and a severing pattern
therefor currently employed in the art are illustrated in
Figures 1 and 2, respectively, of the present specification.
This severing pattern may be employed in either of the
aforementioned methods for the manufacture of such articles.
The article being produced by this pattern is symmetric about
both imaginary longitudinal and transverse centre-lines. The
transverse ends of successive articles are aligned and the
longitudinal side of opposing flaps of successive articles are
substantially in contact with one another. The shaded material
is not used in the production of an article and is therefore
discarded as waste. Depending on the shape of the item being
manufactured, the amount of waste is substantial, which
contributes to an increased manufacturing cost.
Heretofore it appears that manufacturers have sought to
optimise the configuration and shape of the sanitary absorbent
articles generally, and particularly the flaps, on the basis of
characteristics present in the individual final product. In
this respect wearer comfort, absorptive efficiency, and leakage
prevention have generally been taken into consideration. While
the cost of manufacturing is important, little attention has
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CA 02274129 1999-06-04
n ~ r:, i ~E :~,-~ t l :s:l~~- ~'~U rj:_l ''3a~ø~~.rjj : I/ ti
ui-A~tar-~8 I6:t0 ~ From-~EThErcSTO;~ALGH C~ ~~~ -514-454-1395 T-?3i F.06/25 F-
i81
3
been pa_d to designing the individual articles with a view to
reducing the Gmount of waste r.:aterial produced du~-~;ng their
mass-product~cr- by the methods described above, ~.s such
art=c3es are mass-produced in signif_r_an= amour_ts, a reduct_on
J
in waste mace=iai would provide signiLicant savings in the cost
of Tnanu_actu-rirg.
One exGrnple of ~Nh4Ye an arricle has ~weer. dESigned sa a5 to
mi :imize t_:e amount of waste material generated durir_g its
mass-production is described i~: Eurcoear_ Patent ~p'o1=caticn
20 0,280,998 to =ersonal Frcducts Company. T:~is app'~icatior_
describes a pan=y protector =cr ad::esi~re attac:-~ment try the
crotch portions os an un3ergarment comprising a genera-1v
longitudinally extending central portion a:d transversely
extending flaps; the panty protector having a icng_tudinal
_.. cer:~er line an d .a t=ansverse center li r_e an d ~~aving a closed
curve def ~_ni=.g the cuter peri pY:ery of the protaetor, the
protector characterized in. that the closed curve is shaped such
that a portion of the periphery of each of a plurality c=
ider_ticaly shaFed proteC-ors may 'oe butted against a portion
20 of t:~.e periphery of the protector, leaving ro space between
abu~Ling protectors and havir_g no par= cf any protector over=ie
anotrer.
The diLficulty with the art~_c~.es deacr_bed in ~urcpear.
Patent Application 0,280,998 is chat in some instances it may
25 be desired to leave space between abutting procecters _n order
to manufaczurQ absorbent art»'_es having a di;ferent perip heral
shape than t:~at descr;bed therein.
CA 02274129 1999-06-04 r"rC~,i ~.'_,'? ~
.. . _. _ ~l :. ,
_ ~.. ~ .~.~ . ___ ~ , r:" 1- r,-tI:t.n~- ri:~ m;~ _:i:J:JW~ri:~: rl 7
' ~Z-Ma;-99 '61;0 Frcm-~=EThERSTONAUGH ;,0~ ~514-854-1396 T-T31 ~P J~ii9 F-i61
3a
OBJECTS .~.L~TD STA'~"EbLENT OF TIDE =NVLNTICbI
Tt is therefore an object of the present in~rer.ticn to prc~ride
a:: improved sar_itary absorbent article with flaps, s::ch as a
sanitar=r napkin, or a compcnert layer of a sari><ary r.ap;czn,
such as a cover layer, wh::~h ras beer. des_g:ed so as vo reduce
the amount cf waste ~nater_a? generated duri:-:g the raass-
production thereof.
Tt is a further object ef t'r~e present =_~_ventic:-! to
1C pro~ride a metrod of p=~cductior_ of sucn an abeorbea ar tz :_e o=
a componer_t layer. Tt is still a further object of ;.he p=esent
invention tc pro~ride an apparatus for produc~rg such ar_
abso.rber_c article cr comporer~c layer.
Tn one aspect, as embodied and broadly d.eecrbad herei.r.,
the invention provides a plurality of component layers for use
vn sanitary absorbent articles, each compcn~ent layer
corrprisin g
(A) a Main bod~r, said main bo3.~ !awing a Lirst Iran s~ierse
side, a qecond trar_everae ai3e, a first longitudinal
2C side, a szccnd longitudi:.al side, and an i.~rag'_nary
longitudinal emntre-lire;
(H) a first flap projecting laterally from t:=a zirst
longitudinal side of said main body, said first flap
having two longitudinal sides, and said ~irst flan
being positioned with respect to said main body such
that wren
(i? two of the component layers are placed
longitudinal side by longitudinal side, and
~ nrtr;:,!~~~:~ S'~irl
.. m164r~tr
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(ii) one of the component layers is rotated with
respect to the other of the component
layers such that the first longitudinal
side of said main body of each of the
component layers faces the first
longitudinal side of said main body of the
other of the component layers, and
(iii) the first transverse side of said main body
of each of the component layers is aligned
with the second transverse side of said
main body of the other of the component
layers, and
(iv) an imaginary line generally parallel to,
and located in-between, the longitudinal
centre-lines of each of said main bodies of
each of the component layers simultaneously
intersects said first flap of each of the
component layers;
one of the longitudinal sides of said first flap of
one of the component layers is substantially in
contact with one of the longitudinal sides of
said first flap of the other of the component
layers, and
said first flaps of each of the component layers do
not overlap.
In the present specification, the term "component layer of
a laminated absorbent article" refers one of the discrete
layers of which a laminated absorbent article is comprised as
distinct from the other layers of which the same article is
composed. For example, if the laminated absorbent article is a
sanitary napkin, such component layer might be a fluid
permeable cover layer, a fluid impervious barrier layer, a
transfer layer or an absorbent core layer. A component layer
need not be comprised of a single material, but may itself be a
laminate or two or more materials otherwise combined to form an
integral whole. ~ .
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It is preferred that the main body of the component layer
be generally rectangular in shape with rounded ends. When the
component layer is of such a conformation, the first and second
transverse sides are the shorter opposing sides and will
5 generally have an arcuate shape. The first and second
longitudinal sides are the longer opposing sides and will be
straight or arcuate. Preferably, the longitudinal sides are in
an hourglass shape wherein in a central portion of the article
the cross-section is narrower than the cross-section at the
transverse ends. It should be understood however that the
shape of such sides is not essential to the invention, and thus
the transverse or the longitudinal sides could be either
arcuate or straight, or any combination thereof. Nor is it
essential that the main body be generally rectangular, as
component layers having main bodies in the shape of a square,
parallelogram or any other polygon, or even that of an oval,
hour-glass or dog-bone, are all within the scope of the present
invention. Where such is the case (i.e. where the main body is
not rectangular), the longitudinal sides of the layer will be
considered to be those opposing sides of a greater relative
length as compared with the other opposing sides of the main
body. Where it is impossible to make such a determination, any
opposing pair of sides may be considered to be the longitudinal
sides, or at the limit, opposing portions of any two sides may
be considered to be the longitudinal sides. In either case,
the transverse sides are the pair of opposing sides which are
intersected by the longitudinal centre-line of the component
layer, as that line is defined below.
For most component layers, the longitudinal centre-line
thereof is an imaginary line which extends along the
' longitudinal axis of the layer and bisects the layer into two
identical or somewhat identical, yet not necessarily mirror-
image, halves.
It is preferred that the flaps be of a generally
trapezoidal shape with the base of the trapezoid being attached
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6
to the longitudinal side of the main -body. In this manner, the
flap will taper as it projects away from the main body, and the
sides and top of the trapezoid will be generally straight and
will form the longitudinal sides and lateral side of the flap
respectively. It should expressly be understood, however, that
such trapezoidal shape is not essential to the invention, and
flaps of all shapes and sizes are included within the scope of
the present invention. In such cases, the sides of the flaps
generally parallel to the transverse sides of the component
layer should be considered to be the longitudinal sides of the
flap. Where the shape of the flaps is arcuate or other non-
rectilinear shape, the portions of the side of the flap
generally facing in the same direction as the transverse sides
of the component layer should be considered to be the
longitudinal sides of the flap.
It should be understood that the use of the word "flaps"
in the present specification is intended to encompass
extensions of the material of a component layer which directly
form a flap or wing in the article into which the component
layer is incorporated, and those which are indirectly used to
form such a flap or wing. An example of an indirect formation
would be situations where the extension is looped around and a
portion thereof sealed against the barrier layer of the
article. In such cases the remainder of the extension (i.e.
the portion thereof from the barrier layer seal to the distal
extremity) would form the flap or wing in the final article.
In the present context, the word "aligned" is used to
indicate a position of a transverse side of one component layer
relative to that of the other. Two transverse sides are
aligned for the present purposes when an imaginary line
connecting the point at which one transverse side in question
is intersected by the longitudinal centre line of that layer,
with the point at which the other transverse side in question
is intersected by the longitudinal centre line of the other
layer, is substantially perpendicular to the longitudinal
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centre-line of either layer. Two lines are substantially
perpendicular if the angle between them at their point of
intersection is not less than 70° (or more than 110°).
A line "generally parallel to the longitudinal centre-
s lines of the article" in the present specification is meant to
include a line off from parallel with either one of the centre-
lines by at most 20°.
In relation to a component layer of the present invention,
the phrase "substantially in contact" is meant to indicate a
situation where the two flaps in question are in physical
contact with one another or where the distance between them is
small as compared to the total width of the component layer (as
measured from longitudinal side to longitudinal side along the
transverse centre-line thereof. The transverse centre-line of
a layer being an imaginary line in the plane of the layer which
is perpendicular to the longitudinal centre-line). Preferably,
in the case of a component layer for a sanitary napkin, this
distance will not exceed 1/4 of an inch (0.635 cm).
In a more preferred embodiment a component layer of the
present invention further comprises a second flap projecting
laterally from the second longitudinal side of said main body,
said second flap having two longitudinal sides, and said second
flap being positioned with respect to said main body such that
when
(i) two of the component layers are placed
longitudinal side by longitudinal side, and
(ii) one of the component layers is rotated with
respect to the other of the component
layers such that the second longitudinal
side of said main body of each of the
component layers faces the second
longitudinal side of said main body of the
other of the component layers, and
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(iii) the first transve-rse side of said main body
of each of the component layers is aligned
with the second transverse side of said
main body of the other of the component
layers, and
(iv) an imaginary line generally parallel to,
and located in-between, the longitudinal
centre-lines of each of said main bodies of
each of the component layers simultaneously
intersects said second flap of each of the
component layers;
one of the longitudinal sides of said second flap of one
of said component layers is substantially in contact
with one of the longitudinal sides of said second
flap of the other of said component layers, and
said second flaps of each of said component layers do not
overlap.
As embodied and broadly described herein, the present
invention further provides a plurality of sanitary absorbent
articles, each article comprising:
(A) a main body, said main body having a first transverse
side, a second transverse side, a first longitudinal
side, a second longitudinal side, and an imaginary
longitudinal centre-line;
(B) a first flap projecting laterally from the first
longitudinal side of said main body, said first flap
having two longitudinal sides, and said first flap
being positioned with respect to said main body such
that when
(i) two of the articles are placed longitudinal side
by longitudinal side, and
(ii) one of the articles is rotated with respect to
the other of the articles such that the first
longitudinal side of said main body of each of
the articles faces the first longitudinal side
of said main body of the other of the articles, and
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(iii) the first transverse s-ide of said main body of
each of the articles is aligned with the second
transverse side of said main body of the other
of the articles, and
(iv) an imaginary line generally parallel.to, and
located in-between, the longitudinal centre-
lines of each of said main bodies of each of the
articles simultaneously intersects said first
flap of each of the articles;
one of the longitudinal sides of said first flap of
one of the articles is substantially in contact
with one of the longitudinal sides of said first
flap of the other of the articles, and
said first flaps of each of the articles do not
overlap.
Like terms used in the above description should be
attributed the same meaning in the context of the present
aspect as those previously described above in relation to
component layers of the present invention.
In a more preferred embodiment each absorbent article of
the present invention further comprises:
(C) a second flap projecting laterally from the second
longitudinal side of said main body, said second flap
having two longitudinal sides, and said second flap
being positioned with respect to said main body such
that when
(i) two of the articles are placed longitudinal side
by longitudinal side, and
(ii) one of the articles is rotated with respect to
the other of said articles such that the second
longitudinal side of said main body of each of
the articles faces the second longitudinal side
of said main body of the other of the articles,
and
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(iii) the first transverse side of said main body of
each of the articles is aligned with the second
transverse side of said main body of the other
of the articles, and
5 (iv) an imaginary line generally parallel to, and
located in-between, the longitudinal centre-
lines of each of said main bodies of each of the
articles simultaneously intersects said second
flap of each of the articles;
10 one of the longitudinal sides of said second flap of
one of the articles is substantially in contact
with one of the longitudinal sides of said
second flap of the other of the articles, and
said second flaps of each of the articles do not
overlap.
In another aspect the invention provides a method of
manufacturing a plurality of component layers for use in
sanitary absorbent articles, each component layer comprising:
(i) a main body, the main body having a first
transverse side, a second transverse side, a
first longitudinal side, a second longitudinal
side, and a longitudinal centre-line; and
(ii) a first flap projecting laterally from the first
longitudinal side of the main body, the first
flap having two longitudinal sides;
comprising the steps of:
(A) providing a continuous web of material;
(B) severing said web to form a first component
layer and a second component layer arranged one
with respect to the other such that:
(1) the second component layer is rotated with
respect to the first component layer such
that the first longitudinal side of the
main body of one of the component layers
faces the first longitudinal side of the
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11
main body of the -other of the component
layers, and
(2) the first transverse side of one of the
component layers is aligned with the second
transverse side of the other of the
component layers, and
(3) an imaginary line generally parallel to,
and located in-between, the longitudinal
centre-lines of each of the main bodies of
each of the component layers simultaneously
intersects the first flap of each of the
component layers.
The terms used to describe the component layer being
manufactured by the present method should be given the same
meaning as that of like terms set forth hereinabove in relation
to the component layer itself.
It must be understood that for a proper understanding of
these aspects of the invention (i.e. the methods), and those
relating to the apparatus improvements described below, the
evaluation of the positioning of the various component layers
takes place after each layer has been severed (such that the
layer in question exists as a discrete entity), but before it
has been physically removed from the web of continuous
material.
It will be appreciated that many conventional means known
to those skilled in the art may be employed to sever the
component layers from the web. The optimal means may vary
depending on many factors including the material from which the
layer is to be severed. In this respect, die-cutting will
generally be the preferred method although all other
conventional methods, such as laser or fluid-jet cutting for
example, are within the scope of the present invention.
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This method of manufacture of component layers from a
continuous web of material will generate less wasted material
than prior art techniques.
Preferably, the second component layer is severed from the
web such that one of the longitudinal sides of the first flap
of the second component layer is substantially in contact with
one of the longitudinal sides of the first flap of the first
component layer. In this context, the phrase "substantially in
contact" is meant to indicate a situation where the distance
between the two flaps in question is, at a minimum the
clearance distance between layers required by the severing
method being used in order to produce layers of the correct
dimensions. This phrase also includes any greater distance
which is small as compared with the total width of a component
layer (as measured from longitudinal side to longitudinal side
along the transverse centre-line thereof.) As an example,
where die-cutting is the method of severance employed, the
minimum clearance distance is generally in the order of 3/16 of
an inch (0.4763 cm).
More preferably, the present invention provides a method
of manufacturing a plurality of component layers for use in
absorbent articles, each component layer further comprising:
(iii) a second flap projecting laterally from the
second longitudinal side of the main body, the
second flap having two longitudinal sides;
further comprising the step of:
(C) severing from the web a third component layer
arranged with respect to the second component
layer such that:
(1) the third component layer is rotated with
respect to the second component layer such
that the second longitudinal side of the
main body of the second component layer
faces the second longitudinal side of the
~ main body of the third component layer, and
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(2) the first transve-rse side of the second
component layer is aligned with the second
transverse side of the third component
layer, and
(3) the first transverse side of the third
component layer is aligned with the second
transverse side of the second component
layer, and
(4) an imaginary line generally parallel to,
and located in-between, the longitudinal
centre-lines of the main bodies of each of
the second and third component layers
simultaneously intersects the second flap
of the second component layer and the
second flap of the third component layer.
Most preferably, in order to minimize the amount of waste
material generated, the third component layer is severed from
the web such that one of the longitudinal sides of the second
flap of the third component layer is substantially in contact
with one of the longitudinal sides of the second flap of the
second component layer.
As embodied and broadly described herein, the present
invention also provides a method of manufacturing a plurality
of sanitary absorbent articles, each sanitary absorbent article
comprising:
(i) a main body, the main body having a first
transverse side, a second transverse side, a
first longitudinal side, a second longitudinal
side, and a longitudinal centre-line; and
(ii) a first flap projecting laterally from the first
longitudinal side of the main body, the first
flap having two longitudinal sides;
comprising the steps of:
(A) providing a web having at least one layer of
continuous material;
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(B) severing said web to form a first article and a
second article arranged one with respect to the
other such that:
(1) the second article is rotated with respect
to the first article such that the first
longitudinal side of the main body of one
of the articles faces the first
longitudinal side of the main body of the
other of said articles, and
(2) the first transverse side of one of the
articles is aligned with the second
transverse side of the other of the
articles, and
(3) an imaginary line generally parallel to,
and located in-between, the longitudinal
centre-lines of each of the main bodies of
each of the articles simultaneously
intersects the first flap of each of the
articles.
Preferably, the present invention also provides a method
of manufacturing a sanitary absorbent article wherein the
second article is severed from the web such that one of the
longitudinal sides of the first flap of the second article is
substantially in contact with one of the longitudinal sides of
the first flap of the first article.
More preferably, the present invention provides a method
of manufacturing a plurality of sanitary absorbent articles,
each sanitary absorbent article further comprising:
(iii) a second flap projecting laterally from the
second longitudinal side of the main body, the
second flap having two longitudinal sides;
further comprising the steps of:
(C) severing from the web a third article arranged
with respect to the second article such that:
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(1) the third article-is rotated with respect
to the second article such that the second
longitudinal side of the main body of the
second article faces the second
5 longitudinal side of the main body of the
third article, and
(2) the first transverse side of the second
article is aligned with the second
transverse side of the third article, and
10 (3) the first transverse side of the third
article is aligned with the second
transverse side of the second article, and
(4) a imaginary line generally parallel to,
located in-between, the longitudinal
15 centre-lines of each of the main bodies
of
each of the second and third articles
simultaneously intersects the second flap
of the second article and the second flap
of the third article.
Most preferably the present invention provides, a method
of manufacturing a plurality of sanitary absorbent articles,
wherein the third article is severed from the web such that one
of the longitudinal sides of the second flap of the third
article is substantially in contact with one of the
longitudinal sides of the second flap of the second article.
Like terms used in the description of a method of
manufacture of an absorbent article in respect of this aspect
of the present invention should be attributed a similar meaning
as with the terms used to describe the method of manufacture of
a component layer of this aspect of the present invention.
As embodied and broadly described herein, in another
aspect, the present invention further provides in an apparatus
for the manufacture of a plurality of component layers for use
- SUBSTITUTE SHEET (RULE 26)
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is
in sanitary absorbent articles, each component layer
comprising:
(i) a main body, the main body having a first
transverse side, a second transverse side, a
first longitudinal side, a second longitudinal
side, and a longitudinal centre-line;
(ii) a first flap projecting from the first
longitudinal side of the main body, the first
flap having two longitudinal sides;
the improvement comprising a cutter providing for the severance
of a first component layer and a second component layer from a
continuous web of material, the first component layer and the
second component layer arranged one with respect to the other
such that:
(A) the second component layer is rotated with
respect to the first component layer such that
the first longitudinal side of the main body of
one of the component layers faces the first
longitudinal side of the main body of the other
of said component layers, and
(B) the first transverse side of the first component
layers is aligned with the second transverse
side of the second component layer, and
(C) the first transverse side of the second
component layers is aligned with the second
transverse side of the first component layer,
and
(D) an imaginary line generally parallel to, and
located in-between, the longitudinal centre-
lines of each of the main bodies of each of the
component layers simultaneously intersects the
first flap of each of the component layers.
Like terms used in the description of the component layers
and their relationship to one another with respect to the
present aspect of the invention should, to the extent not
varied hereinbelow,' be attributed a similar meaning to as
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17
described hereinabove with respect to other aspects of the
invention.
The term "cutter" is employed in the present context to
denote any device capable of severing a discrete item from a
continuous web of material. All conventional cutters known to
those skilled in the art are within the scope of this aspect of
the present invention. In this respect, such a cutter may
include a die, a blade or other cutting-edge, a laser, or a
fluid-jet.
Advantageously, the cutter is further capable of severing
the first component layer and the second component layer from
the continuous web of material such that one of the
longitudinal sides of the first flap of the first component
layer is substantially in contact with one of the longitudinal
sides of the second flap of the second component layer.
Preferably, as embodied and described herein, the present
invention further provides in an apparatus for the manufacture
of a plurality of component layers for use in sanitary
absorbent articles, each component layer further comprising:
(iii) a second flap projecting from the second
longitudinal side of the main body, the second
flap having two longitudinal sides;
the improvement wherein said cutter further provides for the
severance of a third component layer from the continuous web of
material arranged with respect to the second component layer
such that:
(A) the third component layer is rotated with
respect to the second component layer such that
the second longitudinal side of the main body of
the second component layer faces the second
longitudinal side of the main body of the third
component layer, and
(B) the first transverse side of the second
component layer.is aligned with the second
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18
transverse side of the-third component layer,
and
(C) the first transverse side of the third component
layer is aligned with the second transverse side
of the second component layer, and
(D) an imaginary line generally parallel to, and
located in-between, the longitudinal centre-
lines of each of the main bodies of the second
and of the third component layers simultaneously
intersects the second flap of the second
component layer and the second flap of the third
component layer.
Advantageously, said cutter is further capable of severing
the first component layer and the second component layer such
that one of the longitudinal sides of the first flap of the
first component layer is substantially in contact with one of
the longitudinal sides of the first flap of the second
component layer.
Of a similar advantage, said cutter is further capable of
severing the second component layer and the third component
layer such one of the longitudinal sides of the second flap of
the second component layers is substantially in contact with
one of the longitudinal sides of the second flap of the third
component layer.
As embodied and broadly described herein, the present
invention also provides in an apparatus for the manufacture of
a plurality of sanitary absorbent articles, each sanitary
absorbent article comprising:
(i) a main body, the main body having a first
transverse side, a second transverse side, a
first longitudinal side, a second longitudinal
side, and a longitudinal centre-line;
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(ii) a first flap projecting from the first
longitudinal side of the main body, the first
flap having two longitudinal sides;
the improvement comprising a cutter providing for the severance
of a first article and a second article from a continuous web
of material, the first and second article being arranged one
with respect to the other such that:
(A) the second article is rotated with respect to
the first article such that the first
longitudinal side of the main body of each of
the articles faces the first longitudinal side
of the main body of the other of said articles,
and
(B) the first transverse side of the first article
is aligned with the second transverse side of
the second article, and
(C) the first transverse side of the second article
is aligned with the second transverse side of
the first article, and
(D) an imaginary line generally parallel to, and
located in-between, the longitudinal centre-
lines of each of the main bodies of each of the
articles simultaneously intersects the first
flap of each of the articles.
Advantageously, said cutter is further capable of severing
the first article and the second article from the continuous
web of material such that one of the longitudinal sides of the
first flap of the first article is substantially in contact
with one of the longitudinal sides of the second flap of the
second article.
Preferably, as embodied and broadly described herein the
present aspect of the present invention further provides in an
apparatus for the manufacture of a plurality of sanitary
absorbent articles, each sanitary absorbent article further
comprising: - -
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(iii) a second flap projecting from the second
longitudinal side of the main body, the second
flap having two longitudinal sides;
the impro vement wherein said cutter further provides for the
5 severance of a third article from the continuous web of
material arranged with respect to the second article such that:
(A) the third article is rotated with respect to the
second article such that the second longitudinal side
of the main body of the second article faces the
10 second longitudinal side of the main body of the
third article, and
(B) the first transverse side of the second article is
aligned with the second transverse side of the third
article, and
15 (C) the first transverse side of the third article is
aligned with the second transverse side of the second
article, and
(D) an imaginary line generally parallel to, and located
in-between, the longitudinal centre-lines of each of
20 the main bodies of each of the second and third
sanitary absorbent articles simultaneously intersects
the second flap of the second article and the second
flap of the third article.
Advantageously, said cutter is further capable of severing
the first article and the second article such that one of the
longitudinal sides of the first flap of the first article is
substantially in contact with one of the longitudinal sides of
the first flap of the second article.
Of a similar advantage, said cutter is further capable of
severing the second article and the third article such one of
the longitudinal sides of the second flap of the second
articles is substantially in contact with one of the
longitudinal sides of the second flap of the third article.
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2Z
In still another aspect, as embodied and broadly described
herein, the present invention provides a method of
manufacturing a plurality of component layers for use in
sanitary absorbent articles, each component layer comprising:
(i) a main body, the main body having a first
transverse side, a second transverse side, a
first longitudinal side, a second longitudinal
side, and a longitudinal centre-line;
(ii) a first flap projecting from the first
longitudinal side of the main body;
(iii) a second flap projecting from the second
longitudinal said of the main body; and
(iv) each of the flaps having a first longitudinal
side, a second longitudinal side, and a lateral
side;
(v) said flaps being located substantially at
midpoint between said transverse sides;
comprising the steps of:
(A) providing a web of continuous material;
(B) severing said web to form a first component
layer and a second component layer arranged one
with relation to the other such that:
(1) at least a portion of the first
longitudinal side of the main body of the
first component layer faces at least a
portion of the second longitudinal side of
the main body of the second component
layer, and
(2) an imaginary line generally parallel to,
and located in-between, the longitudinal
centre-lines of each of the main bodies of
each of the component layers simultaneously
intersects the first flap of the first
component layer and the second flap of the
second component layer.
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22
It will be appreciated that this aspect of the present
invention is similar to the method previously described above.
It differs, however, in that the present method allows for the
production of component layers currently employed in the art
that are symmetric about an imaginary transverse centre-line
(such as the article illustrated in Figure 1). Alternative
component layers manufactured according to the present method
need not be rotated.
Preferably, the second component layer is severed from the
continuous web of material such that the first transverse side
of the first component layer and the first transverse side of
the second component layer are non-aligned. In this context
the term "non-aligned" is used to indicate a situation where
the angle formed between the longitudinal centre-line of the
first component layer and the line connecting the point of
intersection of the longitudinal centre-line of that layer with
a transverse side thereof and the corresponding point on the
second component layer is not 90°.
More preferably, the second component layer is severed
from the web of continuous material such that the first
longitudinal side of the first flap of the first component
layer is substantially in contact with the second longitudinal
side of the second flap of the second component layer. The
term "substantially in contact" in this context has the same
meaning as that of the previous method aspect of the present
invention described hereinabove.
Most preferably, the second component layer is severed
from the web of continuous material such that the lateral side
of the first flap of the first component layer is substantially
in contact with the second longitudinal side of the main body
of the second component layer.
Alternatively, the second component layer is severed from
the continuous web'of material.such that at least a portion of
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23
one of the longitudinal sides of the second flap of the second
component layer faces at least a portion of one of the
transverse sides of the first component layer.
Advantageously, the second component layer is severed from
the continuous web of material such that at least a portion of
one of the longitudinal sides of the second flap of the second
component layer is substantially in contact with one of the
transverse sides of the first component layer.
More advantageously, the second component layer is severed
from the continuous web of material such that at least a
portion of the first longitudinal side of the main body of the
first component layer is substantially in contact with at least
a portion of the second longitudinal side of the main body of
the second component layer.
In another aspect, as embodied and broadly described
herein, the present invention provides a method of
manufacturing a plurality of sanitary absorbent articles, each
sanitary absorbent article comprising:
(i) a main body, the main body having a first
transverse side, a second transverse side, a
first longitudinal side, a second longitudinal
side, and a longitudinal centre-line;
(ii) a first flap projecting from the first
longitudinal side of the main body;
(iii) a second flap projecting from the second
longitudinal said of the main body; and
(iv) each of the flaps having a first longitudinal
side, a second longitudinal side, and a lateral
side;
(v) said flaps being located substantially at mid
point between said transverse sides;
comprising the steps of:
(A) providing a web of continuous material;
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(B) severing said web to form a first sanitary
absorbent article and a second sanitary
absorbent article arranged one with respect to
the other such that:
(1) at least a portion of the first
longitudinal side of the main body of the
first article faces at least a portion of
the second longitudinal side of the main
body of the second article, and
(2) an imaginary line generally parallel to,
and located in-between, the longitudinal
centre-lines of each of the main bodies of
each of the articles simultaneously
intersects the first flap of the first
article and the second flap of the second
article.
Preferably, the second article is severed from the
continuous web of material such that the first transverse side
of the first article and the first transverse side of the
second article are non-aligned.
More preferably, the second article is severed from the
web of continuous material such that the first longitudinal
side of the first flap of the first article is substantially in
contact with the second longitudinal side of the second flap of
the second article.
Most preferably, the second component layer is severed
from the web of continuous material such that the lateral side
of the first flap of the first component layer is substantially
in contact with the second longitudinal side of the main body
of the second component layer.
In this aspect of the present invention the terms used
have a meaning similar to that described previously hereinabove
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in relation to a method of manufactura of a component layer for
use in a sanitary absorbent article.
In yet another aspect, as embodied and broadly described
herein, the present invention further provides in an apparatus
5 for the manufacture of a plurality of component layers for use
in sanitary absorbent articles, each component layer
comprising:
(i) a main body, the main body having a first transverse
side, a second transverse side, a first longitudinal
10 side, a second longitudinal side, and a longitudinal
centre-line;
(ii) a first flap projecting from the first longitudinal
side of the main body;
(iii) a second flap projecting from the second longitudinal
1S said of the main body; and
(iv) each of the flaps having a first longitudinal side, a
second longitudinal side, and a lateral side;
(v) said flaps being located substantially at mid point
between said transverse sides;
20 the improvement comprising a cutter providing for the severance
of a first component layer and a second component layer from a
continuous web of material, the first component layer and the
second component layer being arranged one with respect to the
other such that:
25 (A) at least a portion of the first longitudinal side of
the main body of the first component layer faces at
least a portion of the second longitudinal side of
the main body of the second component layer, and
(B) an imaginary line generally parallel to, and located
in-between, the longitudinal centre-lines of each of
the main bodies of each of the component layers
simultaneously intersects the first flap of the first
component layer and the second flap of the second
component layer.
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Preferably, said cutter is further capable of severing the
second component layer from the continuous web of material such
that the first transverse side of the first component layer and
the first transverse side of the second component layer are
non-aligned.
More preferably, said cutter is further capable of
severing the second component layer from the continuous web of
material such that the first longitudinal side of the first
flap of the first component layer is substantially in contact
with the second longitudinal side of the second flap of the
second component layer.
Most preferably, said cutter is further capable of
severing the second component layer from the web of continuous
material such that the lateral side of the first flap of the
first component layer is substantially in contact with the
second longitudinal side of the main body of the second
component layer.
In another aspect, as embodied and broadly described
herein, the present invention provides in an apparatus for the
manufacture of a plurality of sanitary absorbent articles, each
article comprising:
(i) a main body, the main body having a first
transverse side, a second transverse side, a
first longitudinal side, a second longitudinal
side, and a longitudinal centre-line;
(ii) a first flap projecting from the first
longitudinal side of the main body;
(iii) a second flap projecting from the second
longitudinal said of the main body; and
(iv) each of the flaps having a first longitudinal
side, a second longitudinal side, and a lateral
side;
(v) said flaps being located at mid point between
saicr transverse sides;
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the improvement comprising a cutter providing for the severance
of a first article and a second article from a continuous web
of material, the first and second arranged one with respect to
the other such that:
(A) at least a portion of the first longitudinal side of
the main body of the first article faces at least a
portion of the second longitudinal side of the main
body of the second article, and
(B) an imaginary line generally parallel to, and located
in-between, the longitudinal centre-lines of each of
the main bodies of each of the articles
simultaneously intersects the first flap of the first
article and the second flap of the second article.
Preferably, said cutter is further capable of severing the
second article from the continuous web of material such that
the first transverse side of the first article and the first
transverse side of the second article are non-aligned.
More preferably, said cutter is further capable of
severing the second article from the continuous web of material
such that the first longitudinal side of the first flap of the
first article is substantially in contact with the second
longitudinal side of the second flap of the second article.
Most preferably, said cutter is further capable of
severing the second article from the web of continuous material
such that the lateral side of the first flap of the first
article is substantially in contact with the second
longitudinal side of the main body of the second article.
In this aspect of the present invention the terms used
have a meaning similar to that described previously hereinabove
in relation to a apparatus for the manufacture of a component
layer for use in a sanitary absorbent article.
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Other objects and features of the invention will become
apparent by reference to the following specification and the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the preferred embodiments of the
present invention is provided hereinbelow with reference to the
following drawings, in which:
Figure 1 illustrates a top elevational view of a sanitary
absorbent article of the prior art;
Figure 2 illustrates a plurality of prior art absorbent
articles, depicting the severing pattern employed for
separating the absorbent articles from one another.
Figure 3 illustrates a top elevational view of a sanitary
absorbent article of the present invention.
Figure 3a is a cross-sectional view of the napkin shown in
Figure 3;
Figure 4 schematically illustrates the process for
manufacturing absorbent articles in accordance with
the present invention.
Figure 5 illustrates a plurality of absorbent articles,
depicting the severing pattern of the present
invention employed for separating the absorbent
articles from one another.
Figure 6 illustrates a severing pattern of the present
invention for the manufacture of the absorbent
article, or a component layer thereof, depicted in
Figure 1; and
Figure 7 illustrates aJsevering pattern of the present
invention for the manufacture of absorbent articles
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or component layers thereof, in accordance with a
variant.
In the drawings, preferred embodiments of the invention
are illustrated by way of example. It is to be expressly
understood that the description and drawings are only for the
purposes of illustration and as an aid to understanding, and
are not intended as a definition of the limits of the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In Figure 3 of the drawings there is illustrated a
sanitary napkin with flaps, designated comprehensively by the
reference numeral 110, having a flap configuration of the
present invention. Referring to figure 3a, the napkin is of a
laminated construction and preferably comprises a fluid-
permeable cover layer 112, an absorbent system 114, a fluid-
impervious barrier layer 120, and adhesive strips 122 and 124.
Cover layer
The cover layer 112 may be a relatively low density,
bulky, high-loft non-woven web material. The cover layer 112
may be composed of only one type of fibre, such as polyester or
polypropylene or it may be composed of bi-component or
conjugate fibres having a low melting point component and a
high melting point component. The fibres may be selected from a
variety of natural and synthetic materials such as nylon,
polyester, rayon (in combination with other fibres), cotton
acrylic fibre and the like and combinations thereof.
Bi-component fibres may be made up of a polyester core and
a polyethylene sheath. The use of appropriate bi-component
materials results in a fusible non-woven fabric. Examples of
such fusible fabrics are described in U.S. Patent 4,555,430
issued November 26, 1985 to Mays. Using a fusible fabric
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increases the ease with which the cover layer may be mounted to
the adjacent transfer layer and/or to the barrier layer.
The cover layer 112 preferably has a relatively high
degree of wettability, although the individual fibres
5 comprising the cover may not be particularly hydrophilic. The
cover material should also contain a great number of relatively
large pores. This is because the cover layer 112 is intended to
absorb body fluid rapidly and transport it away from the body
and the point of deposition. Preferably, the fibres which make
10 up the cover layer 112 should not loose their physical
properties when they are wetted, in other words they should not
collapse or loose their resiliency when subjected to water or
body fluid. The cover layer 112 may be treated to allow fluid
to pass through it readily. The cover layer 112 also functions
15 to transfer the fluid quickly to the other layers of the
absorbent structure 114. Thus, the cover layer 112 is
preferably wettable, hydrophilic and porous. When composed of
synthetic hydrophobic fibres such as polyester or bi-component
fibres, the cover layer 112 may be treated with a surfactant to
20 impart the desired degree of wettability.
Most preferably, the cover layer 112 is made of polymer
film having large pores. Because of such high porosity, the
film accomplishes the function of quickly transferring body
fluid to the inner layers of the absorbent system. Apertured
25 co-extruded films such as RETICULONT"" brand, for example,
described in U.S. Patent 4,690,679 are useful as cover layers
in the absorbent structures of this invention.
The cover layer 112 may be embossed to the remainder of
the absorbent system 114 in order to aid in promoting
30 hydrophilicity by fusing the cover to the next layer.
Absorbent System -- Transfer Layer
Adjacent to the cover layer 112 on its inner side and
bonded to the cover layer 112 is a fluid transfer layer 116
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that forms part of the absorbent syst-em 114. The transfer layer
116 provides the means of receiving body fluid from the cover
layer 112 and holding it until the highly-dense absorbent core
has an opportunity to absorb the fluid.
The transfer layer 116 is, preferably, more dense than and
has a larger proportion of smaller pores than the cover layer
112. These attributes allow the transfer layer 116 to contain
body fluid and hold it away from the outer side of the cover
layer 112, thereby preventing the fluid from re-wetting the
cover layer 112 and its surface. However, the transfer layer
is, preferably, not so dense as to prevent the passage of the
fluid through the layer into the absorbent core.
The transfer layer 116 may be composed of fibrous
materials, such as wood pulp, polyester, rayon, flexible foam,
or the like, or combinations thereof. The transfer layer 116
may also comprise thermoplastic fibres for the purpose of
stabilizing the layer and maintaining its structural integrity.
The transfer layer 116 may be treated with surfactant on one or
both sides in order to increase its wettability, although
generally the transfer layer 116 is relatively hydrophilic and
may not require treatment. The transfer layer 116 is preferably
bonded on both sides to the adjacent layers, i.e. the cover
layer 112 and the absorbent core 118.
Absorbent System -- Absorbent Core
Immediately adjacent to and bonded to the transfer layer
116 is the absorbent core 118. The absorbent core 118 is
preferably a highly dense layer having a fine porosity. It has
a large liquid holding capacity and it is extremely retentive.
Most preferably, the absorbent core 118 is composed of
compressed sphagnum moss material. More specifically, the
sphagnum moss is formed as a board by air or wet laying and
calendering to obtain a relatively thin, i.e. from about 0.01
to 0.10 inch (0.0254 cm to 0.254 cm) thick, relatively dense,
i.e. from about O.Z- to 1.0 g/cm3 sheet like structure. The
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structure may include a layer of Kraf-t tissue laminated on one
or both surfaces of the sphagnum moss layer. Preferably, a
fibrous component is admixed with the sphagnum moss material.
The fibrous component is suitably a natural or synthetic
textile fibre such as rayon, polyester, nylon, acrylic or the
like, having a length of from about 0.25 to 1.5 inches (0.635cm
to 3.81 cm) and a denier of from about 1.0 to 5. The fibrous
component may be present in an amount from about 2 to 20% by
weight, most preferably from 4 to 8%. The absorbent core 118
may also comprise other components such as wood pulp, synthetic
wood pulp, thermo-mecanical pulp, mechanically ground pulp,
polymers, surfactants, superabsorbents and the like.
In an alternative embodiment the absorbent system 114
includes a single layer of pulp fluff material (the transfer
layer is omitted). The absorbent core 116 preferably comprises
a pulp fluff material and may optionally include other
absorbent materials or non-absorbent materials which aid in
stabilizing the absorbent structure such as conjugate fibres,
fusible fibres, binders, sphagnum peat moss particles,
superabsorbents, and the like and combinations thereof. and may
optionally include other absorbent materials or non-absorbent
materials which aid in stabilizing the absorbent structure such
as conjugate fibres, fusible fibres, binders, sphagnum peat
moss particles, superabsorbents, and the like and combinations
thereof.
Barrier Layer
Underlying the absorbent system 114 is a barrier layer 120
comprising liquid-impervious film material so as to prevent
liquid that is entrapped in the absorbent core from egressing
the sanitary napkin and staining the wearer's undergarment.
Most preferably, the barrier layer 120 is made of polymeric
film, such as polyethylene which is both inexpensive and
readily available. The polyethylene is capable of fully
blocking the passage of liquid or gas that may emanate from the
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absorbent system 114. In a variant, breathable films may be
used that allow passage of gases while blocking liquid.
The cover layer 112 and the barrier layer 120 are joined
along their marginal portions so as to form an enclosure that
maintains the absorbent system 114 captive. The joint may be
made by means of adhesives, heat-bonding, ultrasonic bonding,
radio frequency sealing, mechanical crimping, and the like and
combinations thereof. The peripheral seal line is shown in
Figure 3 by the reference numeral 121.
Adhesive Strips
To retain the sanitary napkin 110 to the wearer's
underpants, adhesive zones 122 and 124 are provided on the
barrier layer 120. The adhesive zones 124, located over the
flaps 126 and 128, bond the flaps to the garment facing surface
of the wearer's underpants, while the adhesive zone 122 serves
to retain the sanitary napkin 110 to the body facing surface of
the underpants.
Flaps
The flaps 126 and 128 are designed to be folded over the
side edges of the wearer's underpants in the crotch portion and
to be fastened to the garment facing surface of the underpants.
The flaps 126 and 128 aid in securing the sanitary napkin 110
in place on the wearer's underpants, and in maintaining the
structural integrity of the sanitary napkin 110 by providing a
"spring-back" action during body movements of the wearer. The
overall effect of the flaps 126 and 128 is to fasten and keep
the sanitary napkin 110 in an optimal exposed shape to provide
the maximum fluid-absorbing surface, whereby reducing the
incidence of failure.
Flap Configuration -- Prior Art
In Figure 1 there is illustrated a sanitary napkin 010
with flap configuration of the.prior art. Such a napkin is
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comprised of a main body 030 having a-first transverse side
032, an opposing second transverse side 034, a first
longitudinal side 036, and an opposing second longitudinal side
038. A first flap 026 and a second flap 028 project laterally
from the main body 030 from the first longitudinal side 036 and
the second longitudinal side 038, respectively. The flaps 026
and 028 are in the shape of a bilaterally symmetrical
trapezoid, with the base being located at the longitudinal side
of the article. The top of the trapezoid forms the lateral
side 040 and 042 of each flap 026 and 028, respectively.
The contour of the sanitary napkin 010 is symmetric about
both an imaginary centre-line 044 extending longitudinally down
the sanitary napkin and an imaginary centre-line 046 extending
transversely across the sanitary napkin 010. Thus, there
exists a line 048 which simultaneously symmetrically bisects
the flaps 026 and 028, and that line 048 is collinear with the
transverse centre-line 046 of the napkin 010.
In Figure 2 there is illustrated a cutting pattern
employed in the prior art to manufacture the napkin depicted in
Figure 1 from a web of at least one layer of continuous
material. In such pattern, like transverse sides of successive
napkins are aligned, i.e. the points of intersection 050a,
050b, 050c of the transverse side 032a, 032b, 032c of each
napkin with the longitudinal centre-line 044a, 044b, 044c of
the napkin are collinear, that line 052 is parallel to the
transverse centre-line 046 of the article 010, and that line
052 is perpendicular to the longitudinal centre-lines 044a,
044b, 044c of the napkins. The lateral sides of opposing flaps
of successive articles face one another (e. g.. the lateral side
040a of the first flap 026a of the first article OlOa faces the
lateral side 042b of the second flap 028b of the second article
OlOb). Such opposing lateral sides 040a and 042b are
substantially in contact in that the distance between them
within the pattern is the minimum clearance distance dictated
by the die being used to sever .them from the web.
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The shaded area in between is not used to produce a napkin
from the web of material and must be discarded as waste during
the manufacturing process.
Flap Configuration -- Present Invention
5 Referring to Figure 3, a sanitary napkin 110 having a flap
configuration of the present invention is comprised of a main
body 130 having a first transverse side 132 and an opposing
second transverse side 134. Each transverse side is arcuate in
shape with no particular curvature being essential to the
10 present invention. The sanitary napkin 110 further has a first
longitudinal side 136 and an opposing second longitudinal side
138, each being generally straight. The shape of the napkin
110 when viewed from above, as shown in Figure 3, is nearly
rectangular.
15 A first flap 126 and a second flap 128 project laterally
from the main body 130 from the first longitudinal side 136 and
second longitudinal side 138, respectively. Each of these
flaps 126 and 128 is in the shape of a bilaterally symmetrical
trapezoid, with the base being located at the longitudinal side
20 of the article. The first flap 126 has a first longitudinal
side 154 and a second longitudinal side 156 formed of the sides
of the trapezoid, and a lateral side 140 formed of the top of
the trapezoid. Similarly, the second flap 128 has a first
longitudinal side 158 and a second longitudinal side 160 formed
25 of the sides of the trapezoid, and a lateral side 142 formed of
the top of the trapezoid. The first longitudinal side 154 of
the first flap 126 and the first longitudinal side 158 of the
second flap 128 each face in the same direction as does the
first transverse side 132 of the main body 130 of the napkin
30 110. In the same respect, the second longitudinal side 156 of
the first flap 126 and the second longitudinal side 160 of the
second flap 128 face in the same direction as does the second
transverse side 134 of the main body 130 of the napkin 110.
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36
The contour of the sanitary napkin 110 is symmetric about
an imaginary centre-line 144 extending longitudinally down the
sanitary napkin 110. A single line 148 simultaneously
symmetrically bisects both the first flap 126 and the second
flap 128. A second centre-line 146 extends transversely across
the sanitary napkin 110, from which the flaps 126 and 128 are
offset. By offset it is meant that the line 148 which
symmetrically bisects the flaps is not collinear with the
transverse centre-line 146 of the napkin 110. The amount by
which the flaps 126 and 128 are offset is described below in
relation to the cutting pattern for the present napkin.
In Figure 5 there is illustrated a cutting pattern of the
present invention to be employed in the manufacture of sanitary
napkins of the present invention from a web of a least one
continuous material. In such a pattern successive napkins
110, 210, 310 are positioned side-by-side, and are rotated.
The first transverse side 132 of the first napkin 110, the
second transverse side 234 of the second napkin 210, and the
first transverse side 332 of the third napkin 310 all face in a
similar direction. Similarly, the second transverse side 134
of the first napkin 110, the first transverse side 232 of the
second napkin 210, and the second transverse side 334 of the
third napkin 310 all face in the same direction. The
alternating sides of successive articles are aligned within the
pattern, i.e. the points of intersection 150, 250, 350 of these
transverse sides 132, 234, 332 (respectively) of these napkins
110, 210, 310 with their longitudinal centre-lines 144, 244,
344 (respectively) are collinear, the line 152 formed by
connecting such points 150, 250, 350 is parallel to the
transverse centre-lines 146, 246, 346 of the napkins, and that
line 152 is perpendicular to the longitudinal centre-line 144,
244, 344 of the napkins.
Further, in the pattern illustrated in Figure 5, like
longitudinal sides of successive articles face one another.
Thus, the first longitudinal side 136 of the first napkin 110
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faces the first longitudinal 236 of t-he second napkin 210, and
the second longitudinal side 238 of the second napkin 210 faces
the second longitudinal side 338 of the third napkin 310, and
so on.
The first flap 126, 226, 326 and the second flap 128, 228,
328 of the napkin 110, 210, 310 are positioned with respect to
the main body 130, 230, 330 (i.e. are offset from the
transverse centre-line 146, 246, 346) such that like
longitudinal sides of like flaps of successive napkins are
substantially in contact with one another. In Figure 5, the
second longitudinal side 156 of the first flap 126 of the first
napkin 110 is in complete contact with the second longitudinal
side 256 of the first flap 226 of the second napkin 210.
Similarly, the second longitudinal side 260 of the second flap
228 of the second napkin 210 is in complete contact with the
second longitudinal side 360 of the second flap 328 of the
third napkin 310.
When such flaps are in complete contact, the lateral sides
of the flaps will be substantially in contact with the
longitudinal side of the facing napkin. Thus, as is shown, the
lateral side 140 of the first flap 126 of the first napkin 110
is in contact with first longitudinal side 236 of the main body
230 of the second napkin 230 and the lateral side 240 of the
first flap 226 of the second napkin 210 is in contact with the
first longitudinal side 136 of the main body 130 of the first
napkin 110. Similarly, the lateral side 242 of the second flap
228 of the second napkin 210 is in contact with the second
longitudinal side 338 of the main body 330 of the third napkin
310, and the lateral side 342 of the second flap 328 of the
third napkin 310 is in contact with the second longitudinal
side 238 of the main body 230 of the second napkin 210.
The shaded area in between successive napkins is not used
in the manufacture of any napkin and must be discarded as
waste. By positioning the flaps of the napkin in accordance
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38
with the present invention, the amount of waste material
generated is significantly reduced as compared with napkins of
the prior art, as graphically illustrated in Figures 2 and 5.
Method of Manufacture of Napkins of the Present Invention
Figure 4 illustrates schematically the various steps in
the assembly process of the sanitary napkin. In a first step,
there is provided a continuous strip 400 of fluid impervious
material which will form the barrier layer of the napkin which
has the desired thickness and is of appropriate width. This
width is equal to the length of longitudinal centre-line of
the articles being manufactured plus any additional width
necessary for the handling of the material by the
manufacturing apparatus.
In a subsequent step, absorbent cores 402 are serially
applied to the continuous web in a spaced apart relationship
in the desired position. The position of each absorbent core
on the web is selected according to the pattern by which the
final products will be severed from the web. The exact
application and positioning of the cores along the web may be
accomplished by several means including a conveyor belt or
vacuum drum.
In a subsequent step, a transfer layer 404 is applied to
the absorbent core by a similar means as with the cores. A
second continuous strip 406 of fluid-permeable material
forming the cover layer of the final articles then applied.
This strip will contact the transfer layers disposed along the
first web, and the barrier layer strip in areas where no
absorbent core/transfer layer is located.
The superposed layers are sealed together at sealing
station 408 along the margins of the absorbent cores in a
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desired pattern to form a continuous compound web. There are a
number of methods which may be used to accomplish this task,
such as adhesives, heat-sealing, and mechanical crimping,
among others. A continuous, laminated, sealed web of material
is thus formed. Adhesive strips are then applied (not shown)
to the exterior surface of the barrier layer material.
It should be noted that the method described above could
be modified to form the sanitary napkins upside down, which
involves starting with the cover layer rather than the barrier
layer. This variant also requires to change the order of
deposition of the transfer layer and the absorbent core, the
transfer layer being placed first followed by the absorbent
core. Finally, the barrier layer is put in place and the
compound web is sealed.
The final step in the process is to sever the individual
articles from the continuous, laminated, sealed web of
material, at cutting station 412 that uses a die-cutting roll.
In this respect, individual articles are severed along the
dark line appearing in Figure 5 by die-cutting.
A second aspect of the present invention allows for the
manufacture of sanitary absorbent articles having a prior art
flap configuration as depicted in Figure 1 with less waste
material generated. This method of manufacture is generally
the same as that previously described with respect to the
first aspect, except that the absorbent cores/transfer layers
are positioned within the web according to the cutting pattern
described hereinbelow.
In this configuration, the napkins OlOa, OlOb, OlOc, OlOd
are positioned side-by-side with successive articles being of
the same orientation (i.e. Opposite longitudinal sides of
successive napkins face one another. Thus, the first
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. ~ 39a
longitudinal side 036a of the first article OlOa faces the
second longitudinal 038b of the second article OlOb and the
first longitudinal side 036b of the second article OlOb faces
the second longitudinal side 038c of the third article 010c.)
The points of intersection OSOa, OSOb, OSOc, OSOd of like
transverse sides 032a, 032b, 032c, 032d of each napkin OlOa,
WO 98/29070 ~ PCT/CA97/00994
OlOb, OlOc, OlOd with the longitudinal centre-line 044a, 044b,
044c, 044d of that napkin are collinear. However, note that
line 052 is not parallel to the transverse centre-line 046a,
046b, 046c, 046d of the napkins, nor is that line 052
5 perpendicular to the longitudinal centre-line 044a, 044b, 044c,
044d of each napkin.
Opposite longitudinal sides of opposite flaps of
successive napkins are substantially in contact with one
another. Thus, the first longitudinal side 054a of the first
10 flap 026a of the first napkin OlOa is substantially in contact
with the second longitudinal side 060b of the second flap 028b
of the second napkin OlOb. Similarly, the first longitudinal
side 054b of the first flap 026b of the second napkin OlOb is
substantially in contact with the second longitudinal side 060c
15 of the second flap 028c of the third napkin OlOc. Similarly,
the lateral side 040b of the first flap 026b of the second
napkin OlOb is substantially in contact with the second
longitudinal side 038c of the main body 030c of the third
napkin OlOc, and the lateral side 042c of the second flap 028c
20 of the third napkin 040c is in substantially in contact with
the first longitudinal side 036b of the main body 030b of the
second napkin OlOb.
A third aspect of the present invention also allows for
the manufacture of sanitary absorbent articles having a prior
25 art flap configuration is depicted in Figure 1 with less waste
material generated. This method of manufacture is generally the
same as those previously described with respect to the first
and second aspects, except that once again the absorbent
cores/transfer layers are positioned within the web according
30 to the cutting pattern described hereinbelow. In this respect,
illustrated in Figure 7 is the positioning of final articles
within the continuous sealed web of the present embodiment, and
the cutting pattern therefor.
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In this configuration, the napkins OlOa, 010b, OlOc are
positioned side-by-side with successive articles being of the
same orientation as the last, however, only a portion of
opposite longitudinal sides of successive napkins face one
another. Thus, a portion of the first longitudinal side 036a
of the first article OlOa faces a portion of the second
longitudinal 038b of the second article OlOb and a portion of
the first longitudinal side 036b of the second article 010b
faces a portion of the second longitudinal side 038c of the
third article 010c. The points of intersection 050a, 050b,
050c of like transverse sides 032a, 032b, 032c of each napkin
OlOa, OlOb, OlOc with the longitudinal centre-line 044a, 044b,
044c of that napkin are collinear. However, note that line 052
is not parallel to the transverse centre-line 046a, 046b, 046c
of the napkins, nor is that line 052 perpendicular to the
longitudinal centre-line 044a, 044b, 044c of each napkin.
As is illustrated in Figure 7, it is preferred that the
contacting portions of the longitudinal sides of successive
articles be substantially in contact with one another in order
to minimize waste material generated.
The above description of a preferred embodiment should not
be interpreted in any limiting manner since variations and
refinements are possible which are within the spirit and scope
of the present invention. The scope of the invention is
defined in the appended claims and their equivalents.
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