Note: Descriptions are shown in the official language in which they were submitted.
1338133
METHOD OF APPLYING ADHESIVE
BACKGROUND OF THE INVENTION
(1) Fleld of the Inventlon
Thls lnventlon relates generally to the method of
maklng an absorbent pad, and partlcularly on the method of
contlnuously applylng adheslve for securing elastlc bands
thereto.
PRIOR ART
Elastlc rlbbon should be applled ln a stretched
condltion to the leg portlons of absorbent undergarments such
as bables dlapers or adult contlnent brlefs. The elastlc
rlbbon ls applled ln a stretched condltlon only ln that leg
portlon so as to cause gathers thereln. The remalnlng portlon
of the elastlc extendlng over the balance of the absorbent pad
ls not adhered to the pad, so that portlon of the pad wlll not
gather. In the manufacture of dlapers and absorbent pads as
well as adult lncontlnent brlefs, an elastlc band ln contlnu-
ous form ls placed agalnst an unrolled web or a contlnuous web
or backlng materlal. The elastlc band has adheslve applled
thereon ln dlscontlnuous portlons therealong, so as to effec-
tuate the attachment of the bands to the backlng materlal
along the leg portlons thereof. Such an apparatus and method
for same ls shown for example, ln U.S. Patent 4,081,301.
Adheslve, as shown ln thls Patent, may be applled ln thln
strands on the elastlc or as lndlvldual dots of adheslve on
-1- ~
64407-42
1338133
the elastlc. The elastlc band ls then applled to dlaper
materlal as the dlaper materlal proceeds along the assembly
processes. As the lndlvldual backlng sheets are cut and
severed from one another, the stretched elastlcs are also
severed. The portlon of the elastlcs that are glued or bound
by adheslve to the backlng sheet of the dlaper cause the
dlaper ln that portlon to gather. The unattached portlons of
the rubber band merely remaln ln the flaccld state ad~acent
the absorbent pad. U.S. Patent 4,371,417 shows an apparatus
for lnsertlng elastlc strlps onto dlapers for stretchlng and
relaxlng predetermlned lengths of the elastlc strlps as they
are secured to the dlaper materlal. U.S. Patent 4,297,157
shows a rather compllcated apparatus for placlng elastlc
strlps under tenslon, onto garments. An annular array of
llnkages and arms are used to apply the elastlc to dlscrete
areas ad~acent the leg openlngs of dlapers.
Another Patent showlng the adheslon of elastlc to
dlsposable dlapers ls shown ln U.S. Patent 4,585,507. An
osclllatlng fork means V-folds longltudlnally spaced portlons
of an adheslve equlpped rlbbon agalnst the backlng sheet of a
dlaper. The V-shaped longltudlnally spaced portlons do not
adhere to thelr respectlve portlons of dlaper and so fall to
cause the requlred gatherlng thereof. U.S. Patent 4,578,133
shows a method and apparatus for applylng strlps of elastlc to
a web of dlaper materlal. The apparatus ls very compllcated
and requlres a dlfflcult method of applylng the strlps to the
web of materlal. Two other recent dlsclosures are shown ln
U.S. Patent 4,572,043 and 4,574,022 whlch agaln also show
-- 2
64407-42
381~3
rather compllcated apparatus for applying discrete lengths of
elastlc materlal to a movlng web of backlng sheet. In U.S.
Patent 4,525,229 an elastlc band ls attached to a tape whlch
ls attached to the web formlng the backlng sheet of the dla-
per. U.S. 4,556,596 shows self adherlng-elastlc strlps
applled to a flexlble base materlal. U.S. 4,543,141 shows
another arrangement for longltudlnally foldlng portlons of the
rlbbon prlor to lts dlsposltlon agalnst a base sheet to
lmmoblllze those portlons of the rlbbon. U.S 4,523,969 shows
an arrangement for grlpplng elastlc rlbbon at several polnts
and stretchlng same prlor to lts appllcatlon agalnst a base
sheet comprlslng the bottom portlon of the dlaper. U.S.
Patent 4,507,163 shows a method of feedlng adheslve onto an
elastlc before lt ls applled to the base of a dlaper.
Though the collectlon of prlor art ls numerous, and
often very compllcated, none of lt appreclates a slmpler
method of performlng the same operatlon.
Thus lt ls an ob~ect of the present lnventlon to
provlde a method of attachlng the elastlc to a web not shown
ln the art.
It ls a further ob~ect of the present lnventlon to
provlde a controllable, contlnuous appllcatlon of adheslve to
a backlng sheet of a dlaper or an adult brlef.
. 3 -
64407-42
1~38133
BRIEF SUMMARY OF THE INVENTION
The lnvention provides in the method of
manufacturing an absorbent pad by applying a plurality of non-
linear continuous bands of adheslve to a continuous moving web
by an adhesive applying machine, the improvement comprising:
passing the web around a rotatable drum; identifying the
amount of web going by the adhesive applylng machlne; e~ectlng
adheslve from a nozzle arrangement onto a web movlng
therepast; movlng sald nozzle arrangement from a flrst
locatlon to a second locatlon durlng motlon of a web therepast
and durlng sald e~ectlon of adheslve thereon; returnlng said
nozzle arrangement from sald second locatlon to lts first
location as a web moves therepast; and continuing said
movement of said nozzle arrangement between sald flrst and
second locatlons based upon the movement of a web therepast.
The lnventlon also provides ln the method of
manufacturing an absorbent pad by applylng a plurallty of non-
llnear continuous bands of adhesive to a continuous moving web
by an adheslve applying machine, the improvement comprlsing:
running a continuous web of backing material ad~acent a pair
of movable adhesive nozzles; measuring the movement of web in
relation to the adhesive nozzles; e~ecting adhesive from said
nozzles onto said movlng web; movlng the nozzles sldeways from
a flrst locatlon a limlted amount to a second locatlon so as
to form a palr of non-llnear beads of adheslve onto sald
movlng web; and holdlng the nozzles at thelr "away" posltlon
for a deslred perlod of tlme.
The elastlc band rlbbon ls of contlnuous length, and
ls applled agalnst a contlnuous strlp of adheslve placed upon
-- 4
64407-42
:,. ,
1338133
the movlng web. The contlnuous strip of adheslve ls applled
on a nonllnear manner to the movlng web. The web whlch may
comprlse the back sheet of a dlaper or an adult lncontinent
brlef, or the llke, ls caused to move about on a rotatable
roller or drum. Subsequent to the web movlng on the roller lt
ls caused to travel upon a conveyor belt where lt meets an
upper layer of fluff materlal and a topmost layer. As the web
moves around the roller, a palr of adheslve e~ectlon nozzles
apply a contlnuous strlp of adheslve dlrectly to the movlng
web. The nozzles are shlfted transversely durlng the
appllcation of the strlp of adheslve onto the movlng web so as
to effect a generally stepped or "slnusoldal" pattern of
adheslve thereon.
The method of the present lnventlon lnvolves feedlng
an elastlc rlbbon to an assembly statlon ln a stretched
condltlon; supplylng a contlnuous web of materlal such as
backlng sheet to an assembly statlon ln a tensloned condltlon;
feedlng an elastlc rlbbon to the assembly statlon ln a
stretched condltlon; applylng adheslve ln a contlnuous manner
to the web of materlal; movlng transversely the adheslve
appllcatlon nozzles whlle sald web ls movlng; returnlng sald
adheslve applylng nozzles to thelr orlglnal posltlon whlle
sald web ls movlng; and tlmlng the movement of the adheslve
applylng nozzles ln con~unctlon wlth the speed of the movlng
web so as to properly effectuate a generally stepped
repetltlve pattern of adheslve thereon.
- 4a -
, -
~ 64407-42
- 1338133
Flnally, the elastlc rlbbons are attached to portions of the
adheslve bands that ls applled to the backlng sheet as lt goes
around the roller.
The apparatus at the assembly statlon for manufactur-
lng the absorbent web of materlal comprlses a rotatable roller
or drum supported on an axls. The rotatable drum has a flrst
ldler roll supported thereabove. A web of backlng materlal of
a lndetermlnate length ls dlsposed over the flrst ldler roll
and around the drum. The web of materlal ls contlnued over a
second idler roll and arranged to be contlnuously transported
on a conveyor belt on whlch lt recelves a layer of absorbent
fluff materlal and a top sheet. An adheslve applylng mechan-
lsm ls dlsposed ad~acent the drum so as to apply a palr of
contlnuous strlps or bands of adheslve agalnst the web as lt
wraps around the drum.
The adheslve applylng mechanlsm comprlses a lower
frame. The lower frame conslsts of a palr of upstandlng legs
across whlch ls dlsposed a transverse mountlng plate. The
mountlng plate ls generally parallel to the axls of the drum.
A flrst movlng means ls flxedly attached to the generally
mld-portlon of the mountlng plate and ls attached to the
movable portlon of the flrst movlng means. The movlng means
may comprlse a double actlng alr cyllnder. A mlddle plate ls
movedly dlsposed above the mountlng plate. A support means ls
arranged on each end of the mlddle plate. The support means
permlts the mlddle plate to be moved transversely wlth respect
to the mountlng plate therebeneath. A llnkage ls arranged
between the double actlng alr cyllnder and the mlddle plate so
-- 5
- 64407-42
- 1338l33
as to effect sald movement.
A palr of upper plates are movably supported on the
mlddle plate. Each upper plate carrles an adheslve nozzle.
Each upper plate ls ad~ustably movable generally longltudlnal-
ly, wlth respect to the mlddle plate. Each upper plate has a
manual ad~ustment means so as to permlt the settlng of the
inltlal locatlon of the upper plate wlth respect to the mlddle
plate. Each upper plate has a second movlng means thereon,
such as a double actlng pressure cyllnder thereon. The pres-
sure cyllnder may be attached to the adheslve nozzle by aconnectlng rod. Each adheslve nozzle is permltted to sllde
transversely wlth respect to the upper plate. Each pressure
cyllnder on the upper plate ls connected by proper means to a
solenold valve means whlch effectuates enactment of transverse
movement of the adheslve nozzles wlth respect to the upper
plates on whlch they are slldably dlsposed.
The flrst movlng means on the lower mountlng plate ls
connected to a pressurlzable source controlled by a solenold
valve for actuatlng the alr cyllnder therewlth. The flrst
movlng means effectuates movement of the mlddle plate and
therefore the movement of the adheslve nozzles radlally toward
and away from the drum on whlch the web ls carrled. The adhes-
ive nozzles, belng heated, are of necesslty moved away from
the web of materlal when the web of materlal has stopped
movlng, so as to prevent any burn through thereof. A proper
control system effectuates the tlmlng of the second movlng
means so as to control the transverse movement of the adheslve
nozzles whlle they are deposltlng a strlp of adheslve onto the
-- 6
64407-42
1338133
web or backlng sheet of materlal as it ls moved about the
drum. A palr of arms extend down from the transversely lmmov-
able mlddle plate. At the dlstal end of each arm there ls
dlsposed a pulley. The pulley guldes the elastlc strlp prlor
from lts supply roll to lts llnear dlsposltlon on the adheslve
strlp and alternatlvely, to the non-adheslve portlon of the
web or backlng sheet.
When each of the adheslve nozzles have moved
transversely outwardly, they are stlll caused to contlnuously
deposlt the strlp or bands of adheslve out of the normal path
of the elastlc bands. As the web of materlal ls drlven around
the drum, and the elastlc bands are held thereagalnst, that
portlon of the elastlc bands whlch are not ln abuttlng contact
wlth the adheslve strlp on the web, wlll not stlck to the web.
Therefore the elastlc band ln those noncontactlng, nonadherlng
areas wlll not cause the absorbent materlal to "gather"
thereon when the elastlc band has been cut and hence when lt
returns to lts stretched state.
The absorbent pad manufactured by the apparatus and
method descrlbed hereabove has a palr of adheslve strlps whlch
are dlsposed outwardly from thelr llnear paths, on each slde
of the leg cut-out portlons. Thus the adheslve strlps or
bands form a generally stepped conflguratlon, the adheslve
actlng to secure the fluff layer agalnst the bottom layer of
the pad, where the adheslve ls not contactlng any elastlc
band. The adheslve thereby also acts as a fluld barrler to
help mlnlmlze fluld mlgratlon lnto the slde flaps of the pad,
dlaper or brlef. The fluld, such as urlne, ls thereby
.
64407-42
133813~ `
directed along the mld-portlon of the pad, helplng to mlnlmlze
leakage and uncomfortablllty ln the pad.
BRIEF DESCRIPTION OF THE DRAWINGS
The ob~ects and advantages of the present lnventlon
wlll become more apparent, when vlewed ln con~unctlon wlth the
followlng drawlngs, ln whlch:
Flgure 1 ls a perspectlve vlew of an assembly statlon
of the present lnventlon havlng a palr of osclllatable glue
guns shown dlsposed agalnst a backlng sheet;
Flgure 2 ls an elevatlonal vlew of the end of the
drum and adheslve appllcatlon apparatus;
Flgure 3 ls a vlew slmllar to Flgure 2, wlth the
appllcatlon apparatus moved away from the drum.
Flgure 4 ls a slde elevatlonal vlew of the adheslve
appllcatlon apparatus;
Flgure 5 shows a perspective vlew of an absorbent pad
lndlcatlng the pattern of adheslve strlp thereon and the
elastlc band thereattached;
Flgure 6 shows a perspectlve vlew of the absorbent
pad of Flgure 5, ln an unstretched state; and
Flgure 7 ls a vlew taken along the llnes VII-VII of
Flgure 5.
64407-42
-- 1338133 q 64407-42
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in detail, and particularly
to Figure 1, there is shown an asæembly station 10, utilizable
in the manufacture of absorbent pads such as baby diapers or
adult incontinent briefs. This application concerns subject
matter that is related to that of copending Canadian patent
applications Serial Nos. 569,013 and 569,020.
A rotatable roller or drum 12 is shown in
perspective, having a web 14 of indeterminate length,
comprising "backing material" movably disposed therearound.
The web 14, moving in a direction as indicated by the arrows
thereon, is coming from a source, such as a supply roll, not
shown. The web 14 first passes over a first idler roll 16,
before it wraps around the drum 12. The web 14 then passes
over a second idler roll 18 before it begins its journey on a
main conveyor belt system 20, only a portion being shown for
clarity.
A feed conveyor belt system 22, is shown on the left,
in Figure 1, wherein a layer of absorbent fluff material 24 and
a liquid permeable top sheet 26 are juxtaposed in contacting
overlying relationship with the web 14 of backing material.
The web 14 of backing material is made of a plastic or like
liquid-impermeable material.
A primary adhesive applying mechanism 30, comprising
a pair of movable nozzles 32 and 34, are arranged so as to
apply a generally stepped array of adhesive portions comprising
a non-linear strip of adhesive 36 on the web 14 as it winds
around the drum 12. A pair of arrows "A" show the transverse
motion available to the movable nozzles 32 and 34. Only the
nozzles 32 and 34 of the adhesive applying mechanism 30 are
shown for clarity, in Figure 1.
13381~3
A palr of elastic bands 38 ls shown, being gulded
over a palr of pulleys 40. The pulleys 40 are rotatlvely held
on the lower ends of a palr of arms 41. As the drum 12 ls
caused to rotate (clockwlse as shown in the drawlngs), the
elastlc bands 38 are caused to be pressed agalnst portlons of
the strlp of adheslve 36 already deposlted on the advanclng
web 14. The elastlc bands 38 are thus flxedly attached only
to those llnear portlons of the web 14, where the adheslve
strlps 36 are ln llne with the elastlc bands 38, such as the
linear strip of adhesives shown in Figure 1 at 36'. The
elastlc bands 38, belng held ln a llnear manner as the drum 12
rotates, comes lnto non-adherlng contact with the web 14
~backlng sheet), because the strlp of adheslve 36, such as
lndlcated by 36" ls not ln contact or allgnment therewlth, by
vlrtue of the movable nozzles 32 and 34 havlng been actuated
to thelr respectlve sldes (left and rlght).
The adheslve applylng mechanlsm 30 ls shown more
clearly ln Flgures 2, 3 and 4. The mechanlsm 30 ls elongated,
and as such, ls generally parallel to the axls of rotatlon of
the drum 12. The adheslve applylng mechanlsm 30 has a lower
frame 50, havlng a palr of upstandlng legs 52, across whlch
there ls dlsposed, a transverse mountlng plate 54. The
mountlng plate 54 ls shown most clearly ln Flgure 4. A flrst
movlng means 56 is secured to the mld-portlon of the mountlng
plate 54. The flrst movlng means 56 may comprlse a double-
actlng pressurlzable cyllnder 58, havlng a piston rod 60
extendlng therefrom. The plston rod 60 ls attached to a
bracket 62 extendlng downwardly from a mlddle plate 64. A
-- 10 --
-
64407-42
1338133
-
support means 66, ls arranged on each end of the mlddle plate
64. Each support means 66 comprlses a sllder 68 arranged to
move back and forth on a bar 70.
A palr of upper plates 72 and 74 are movably sup-
ported above the mlddle plate 64. An end frame 76 extends
upwardly from each end of the mlddle plate 64, and a gulde
frame 78 extends upwardly from the mlddle of the mlddle plate
64. A palr of sllde shafts 80 are arranged between the end
frames 76 and extend through the gulde frame 78. Each upper
plate 72 and 74 has a houslng 82 and 84 respectlvely whlch ls
supported on and slldes upon the sllde shafts 80. A palr of
rotatable threaded shafts 86 and 88 are dlsposed through one
end frame 76 on one slde of the mlddle plate 64, as shown ln
Flgure 4. Each threaded shaft 86 and 88 has a handle 90, by
whlch they may be rotated. A captlve nut 92 ls secured to the
bottom of each houslng 82 and 84. Rotatlon of the handles 90,
wlll rotate each threaded shaft 86 and 88, each wlth respect
to lts captlve nut 92, so as to cause slldlng movement, for
transverse manual ad~ustment, of the upper plates 72 and 74
and hence thelr respectlve nozzles 32 and 34, with respect to
the mlddle plate 64. Each arm 41 supportlng the pulleys 40
are attached at thelr upper end, to one of the upper plates 72
or 74. Ad~ustment of the nozzles 32 by ad~ustment of the
handles 90 wlll concomltantly ad~ust the pulleys 40, and
thereby, the locatlon of the elastlc bands 36.
Each nozzle 32 and 34 is also arranged for transverse
slidlng movement on thelr respectlve upper plates 72 and 74. A
palr of nozzle support frames 100 extend upwardly from each
-- 11 --
64407-42
1338133
upper plate 72 and 74.
A nozzle shlftlng means 102 ls arranged on each upper
plate 72 and 74 to effectuate the transverse movement of the
nozzles 32 and 34 thereon. The shlftlng means 102 ln thls
embodlment preferably comprlses a pressurizable double actlng
plston and cyllnder unlt 104 secured to the dlstal-most ends
of each upper plate 72 and 74. A plston rod 106 extends
movably through its outermost respectlve support frame 100.
The plston rod 106, ls attached at lts dlstal-most end, to a
nozzle bracket 108. A palr of nozzle support rods 110 are
arranged between each palr of nozzle support frames 100. The
nozzle brackets 108 each sllde on thelr respectlve nozzle
support rods 110.
Each nozzle 32 and 34 has a heatlng element, not
shown, arranged therewlthln, so as to malntaln the adheslve
supplled thereto, ln a fluld state. Each nozzle 32 and 34 has
proper adheslve supply means, under pressure, to permlt a
contlnuous e~ectlon of adhesive onto the "backlng" sheet web
14 as lt moves therepast.
Each plston and cyllnder unit 104 ls connected
through proper means, not shown, to a regulator 120, such as a
solenoid valve arrangement. The regulator 120 provides the
means for controllably shlftlng each adheslve nozzle 32 and 34
transversely, so as to effectuate the non-llnear (almost
slnusoldal) stepped pattern of adheslve onto the web 14. The
regulator 120, whlch provldes the pressure to the proper
portlon of the plston and cyllnder unlts 104, ls controlled by
a slgnal generator means 122, whlch is arranged on the drum
- 12 -
:
64407-42
1338133
12. The slgnal generator means 122 sends signals to a
counter, not shown, whlch provldes the lnput to the regulator
120, swltchlng the valvlng thereln to effectuate proper trans-
verse movement of the nozzles 32 and 34. The regulator 120
may also effectuate energlzatlon of the flrst movlng means 56
to cause the mlddle plate 64 to move toward or away from the
drum 12 and web 14. Thls ls presented ln Flgure 3, whereln
; the nozzle 32 ls shown wlthdrawn from the surface of the web
14. Whenever the web 14 ls not movlng, a slgnal may be sent
to the regulator 120 to pressurlze the plston-cyllnder unlts
58 to move the nozzles 32 and 34 away from the web 14, so that
they wlll not burn through or melt the plastlc (typlcally) web
14. When the web 14 ls not movlng, the nozzles 32 and 34 are
held away from the web 14, so that they wlll not burn through
or melt the plastlc (typlcally) web 14. When the web 14 ls
actually movlng, the nozzles 32 and 34 are pressed sllghtly
agalnst the web 14 for posltlve contact, as shown by the
sllght bulge "B" ln the web 14, ln Flgure 2.
A secondary arrangement of adheslve applylng nozzles
130 ls shown ln Flgures 1 and 2. The secondary nozzles 130
dlstrlbute a llnear array of thln strands of adheslve 132
across the entlre web 14 as shown ln Flgures 1 and 7. The
thln strands of adheslve 132 are utlllzed to help secure the
layer(s) of fluff 24 agalnst the web 14 (backlng sheet), and
to secure the perlpheral portlons of the top sheet 26 to the
web 14 (backlng sheet).
The assembly of absorbent pads such as dlapers and
adult lncontlnent brlefs ls shown ln a somewhat slmpllfled
- 13 -
64407-42
1338133
-
manner ln Flgure 1. The fluff 24, havlng an "hour glass"
conflguratlon, whlch deflnes the "leg" portlons, ls secured
between the "backlng" sheet web 14 and the upper layer 26 as
they proceed onto the maln conveyor belt system 20. At thls
con~uncture, the elastlc bands 38 are stlll malntained ln a
"stretched" condltlon whlle, the adheslve that portlon of lt
are placed agalnst, sets. A leg area cuttlng means 140,
performs a cuttlng operatlon on the backlng web 14 and the
upper sheet 26 so as to create the "hourglass" conflguratlon
on all the remalnlng layers of the absorbent pad.
A transverse cuttlng means 142 makes a cut across the
contlnuous llne of layers of web 14, fluff 24 and top sheet 26
at proper tlmed lntervals to deflne a "walst" edge 145, and to
create lndlvldual absorbent pads 144, such as dlapers or adult
lncontlnent brlefs from the oncomlng lndetermlnate length of
same proceedlng down the conveyor system 20.
Once the transverse cut has been made, the elastlc
bands 38 are no longer under tenslon. That portlon of the
elastlc bands 38 whlch was placed over the adheslve 36' whlch
was ln allgnment therewlth, and thus contracts to form
"gathers" ln the absorbent pad 144, as shown on the rlght hand
slde of Flgure 1, and ln Flgure 6. The remainlng elastlc band
38 merely becomes loose and flaccld.
The remalnlng adheslve 36 to whlch no elastlc band ls
attached, provldes a strong bond wlth the fluff 24, as shown
ln Figure 7. Thls bond wlth the fluff 24 extends ln a gen-
erally parallel manner up both sldes of the absorbent pad 144,
to the walst edge 145. That extended band of adheslve 36"
- 14 -
64407-42
1338133
becomes a moisture dam to facilitate directional flow of urine
away from the sides of the absorbent pad 144 where it might
tend to leak.
Thus the continuous non-linear band of adhesive ar-
ranged on the backing sheet of the absorbent pad 144 provldes
a multlple functlon. It permits the elastlc band 38 to be
adhered to the pad where it is necessary, thus providing the
"gathers" therein for snug fit around a wearer's legs, while
also permitting a liquid damming functlon to occur, so as to
dlrect urlne from potential areas whlch are prone to leakage.
- 14a -
64407-42
