CA2164431A1

CA2164431A1 - Absorbent article and method of manufacturing article

Info

Publication number: CA2164431A1
Application number: CA 2164431
Authority: CA
Inventors: Migaku Suzuki; Hiroaki Fukui
Original assignee: Individual
Current assignee: Paragon Trade Brands LLC
Priority date: 1993-06-03
Filing date: 1994-06-03
Publication date: 1994-12-22
Also published as: JPH06343660A; WO1994028845A1; JP3144514B2

Abstract

This invention is an absorbent article comprising a main body (1) having a waist hole (3) and a pair of leg holes (4), an elastic waist portion (5) disposed along the waist hole (3), and a leg gather (6) disposed along each of the leg holes (4). The main body comprises a front section (1A) and a rear section (1B) joined to each other in a crotch region (2b) and side regions (2a) of the main body (1). The front section (1A) has at least one constituent element whose property is different from that of the corresponding element of the rear section (1B). The absorbent article is fully responsive to a variety of article configurations or constructions which require the front (1A) and rear (1B) sections to function differently or individually. A method for manufacturing such an absorbent article is also disclosed.

Description

WO 94/28845 21 6 4 ~ 3 1 PCT/US94/06230 ABSORBENT ARTICLE AND METHOD OF MANUFACTURING ARTICLE
BACKGROUND OF THE INVENTION
The present invention relates to an absorbent article such as an infant diaper or an adult diaper, and further to a method for manllfa~fhlring such an itbSU~ article.
S Absorbent articles, particularly infant and adult diapers include s ~ type diapers and integral-type or tapeless-type diapers. The S~dlate type diaper is con~l.ulcd to be b~ from opposite sides of its waist region so that it can be developed into a flat confi~ f n, and includes fastening tapes for releasably C'~n.f~ f~g front and rear waist regions of the diaper when applying the diaper to a user's body. The l~des~ type diaper is a pant-type diaper which includes a waist hole and a pair of leg holes. Both the ~,l type and the I lj -'~ type diapers include a main body which co..~p. ;~ec a liquid i",~ b!^
b= L`l~f~ , a liquid pfrmf~ ^ and hydrophobic topsheet ~u~ ~sc-~ onto the ha~kchf-~t and an ll core interposed between the topsheet and the Ibaf~ r~t. The main body is configured to include an e~ ;f; ~1 waist portion and a pair of leg holes. Fcpe~;ally~ the 15 tA~l~~ type diapers have recently gained h.~,res~cd ~c~lJ~ fc from f~l.~ ` for their ad~ .l~u~ f~ t~ ;,u;. ~ of stability during use and applicability to standing users, which are best suited for their arpliratif n to infants who have just started wallcing.
G,ll~ tional .-' type articles include pant-type and ~u~l)o~t~-type articles.
One example of the pant-type article is illustrated in JPA No. 3-82467wherein a b~L':h-'. ,1 20 formed of an elastic non-woven fabric, covers both of front and rear sections of the diaper.
U.S. Patent No. 4,938,757discloses a diaper typical to the ~u~ c,lh.-type article which includes elastic side bands for cf...nf.-l;~.~ side ends of a front section and side ends of a rear section.
When ~-- . -r l---;..g these articles, main bodies of the articles are r ~~ ~ l~d with their lfu~ l direction being arranged either in a machine direction (MD) or in a 25 cross-machine direction (CD), and integrally-formed front and rear sections of each of the main bodies are then bi-folded for side sealing of respective, opposite side ends thereof.
However, such ~l -- r~ .g methods as mfntirn~l above have certain lim;tationc in ter-m--s of productivity and feasibility to ~xa~ various article c~ llu.;lious.
In order to improve the productivity of those articles, JPA No. 3-123551 ~;u~J~JOSeiS a method 30 wherein a 1'~ `.1.rrt jS placed on a bi-folded main part COIl""isi"g a topsheet and an q' ~ ~11 core placed thereon prior to heat-sealing along wing and leg portions of an article.
It has been recognized that such conventional tapeless-type ~ .-I articles are unable to fully ~r~ .... or~ato various product features sought for more dPci~ article confi~. J - during use or more gener-specific article cperifir~ti~nc For eY~ a 3~ desirable location of a ma~imllm absorbing capacity is different between diapers for mail and female. In order to meet such needs, an absoll,.,.lt core is required to have different ~' billg c-l--~-;l;~c, therefore different ql~an~i~i.oc of absoll,cnt material between opposite sides of a crotch portion of an article.

~ / PCT/US94/06230 ~ . --However, such provision of different quantities of absorbent material between front and rear sides of the absorbent body consequently creates differences in ll.;~L..~c~ and rigidity between a front side and a rear side of the al)soll,ent body exactly along its center line.
When the folding of the absorbent body is not made at a correct position, the topsheet 5 ~ e,~osed on the absorhent hody is also hi-folded at an off-center position so that opposite ends of the topsheet are misaliLmed to form an irregular waist profile after hea t-sealing thereof to the absorbent core. This reduces the product value of the resulting article.
In order to minimi7~ production of such inferior articles, it is required to effect e~act ~lignm~n~ of opposite ends of the topsheet when it is bi-folded. It is, however, difficult 10 to hold such flexible material correctly in a desirable position by present col.u.le.~;..lly available e~lui~ ,nl, which results in an increased ~uil.llle,.t cost and reduced productivity as well.
It is an object of the present invention to provide a tapeless al)so,l~l,l article which is capable of elimin~ino the above-described disadvantages of conventional tapeless articles that are ~enerally caused by the necessity of bi-folding of ~so,l.~.lt cores.
Another object of the present invention is to provide a method for ............. -,.. r- ~.. ;.. g such an improved absorbent article.
SUMMARY OF THE INVENTION
The present invention provides an ab~ull,~nt article which co.ul.~;q.~-c a main body having a waist hole and a pair of leg holes, an elastic waist portion disposed around the waist 20 hole, and an elastic leg gather disposed around each of the leg holes. The main body cu"lyliae~ a front section and a rear section. The front and rear sections have different con~llu~ilions from each other and are ronnecte~l to each other in a crotch regions and side regions of the article. Each of the front and rear sections Culllpfis~,s a b~ . a topsheet disposed inwardly of the h~ckch~et and an absorbent body hlle-~,osed between the topsheet 25 and the bPckchPP~t Because the ~baullJenl article of the present invention has the front and rear sections which have respective individual con~l. u,_lions formed of respectively selected, desirable m~eri~lc, the article is capable of ~rcomm~ fin~ various features so that the front and rear sections are allowed to function s~hc~S~n~i~lly in-lepPr~ n~ly from each other.
When the absorbent article of the present invention is used as a diaper for infants who frequently lie with their t:aces down, the front section may comprise a highly ' - b~t element co~ O a c."..l,h,~tion of pulps and su~e.~bso.l,~ t materials and the rear section may comprise a thin and expansive dl s~ ..l element. This permits front and rear portions of the article to exhibit urine absorhent capacity and capacity of treating fecal material, 35 l~alJeelively.
It is preferable that the tront section having high hbaull/;llg ~p~r.i~;~s has an overall dimensionally stable construction including an absu.l,~nt body and the rear section is provided with elastic materials to be more flexible.

WO 94/28845 ~ 216 ~ PCT/US94/06230 The front section may comp}ise a topsheet formed of a hydrophobic, bulky, fine-mesh sheet treated to be hydrophilic and the }ear section may comprise a topsheet formed of a hydrophilic coarse mesh sheet so that the above-mf~nfion~ urine absfJ,l,...t capacity and the capacity of treating fecal material thereof can be fully .-Yhihj~PA
S Furthermore, the front section may comprise a b~ ,t formed of a highly liquid-resistant film and the rear section comprises a b~c~ t formed of a highly air-permeable film so that improved comfort is provided to users during use. Different coloring or patterning of the h~rl~chæ~t betwæen the front and rear sections permits users to identify the fronL and rear portions of the absorbent articlæ at a glance.
As described above, the method of ~ccemhling the front and rear sections separately from each other and thereafter joining them provides various advantages in dPci~ing a variety of absollJ~ article co~ ,uclions. However, there exist ~.,,'' to be solved since the alJ~fJI~ article has in its crotch region the sf~;ul~."~.,l region.
A first problem comes from thG sæcu,~."~.,t of the front and rear portions of the 15 ~ bGIIt body. The prohlæm nGGds to he solved by joining them without any defects. A
second problem comes from the securement of front and rear portions of the gather. For ~Y~mrle the simple securement of the front and rear portions may disturb c~ ;t;es thereof.
It may prevent the standing leg gathers from standing up in the sccul~ ..t region. Therefore, it becomes hll})GIlhi)t to solve the problem by ...~ ;..g co..lh.uily of the front and rear 20 shnding gather portions.
Now the s~~u,e."~ nt of the front and rear Al,~.b~..t body portions will be eYp!qin~l Each of the front and rGar sections has a central region inrl~ ing a topsheet, a b~fL~ cl and an absorbent hody, and a marginal end i-.clu.l;,.g the topsheet and the l,a- L . l ~ ~ t The respectivG marginal encls of the front and rear sections are joined together to 25 form a tab. ThosG marginal ends may he joined to each other typically by heat bo..d;"g. The heat-bonding may be effected by a plurality of lines or by relatively wide bands to obtain stable ~f~u~ .cnt results. It is preferred that the ends inrlu-ling the ~so.l-~.-t bodies are p~c~iu~ y joined to each other by hotmelt adhesives before the marginal ends are heat-bonded to each other. This provides improved, urine leakage protection.
In order to ohtain more stahle sGculc~lle.lt, it is advantageous that a ,e;.. f.. ,;.. g member is additionally attached to the se ;u-- ."~ nt region. One ap~ ach iS to provide a tape-Iike ~;"f,.c;"g member along a houndary in a crotch sf~ul~ nl region of the front and rear sections. Such a reinforcing memher needs to be liquid-pG- If '-1^ and p~erclal)ly c~ --;~s a highly liquid-permeable porous non-woven fabric.
Another effective method is to insert a heat-sealable sheet between the facing top surfaces of the front and rear sections. The heat-sealable sheet is bonded to the front and rear sections ciml~ neollcly as they are heat-honded to form the crotch S~ .,.c,.t region. In wch an event, while one end of the heat-scalahle sheet is bonded to the sec,~ .,t region together 2~ 3 ~ PCT/US94/06230 , with the topsheets and h~kch~e~; another end thereof is unsecured to project upwardly like a petal in a central portion of the absorbent article. This projecting portion serves to separate the front portion from the rear portion of the article and has an effective function to separate urine from fecal material. Accordingly, the p,~,ju;Ling portion may be preferred to as ~a 5 si~d~alh~g petal". The separating petal may comprise a heat-sealable film or non-woven fabric, preferably an elastic and heat-sealable cl..i,L(J",e,ic film or non-woven fabric such as of ethylene vinylacetate co-polymer (E.V.A.),stylene ethylene butodiene stylene block co-polymer (S.E.B.S.),or stylene ethylene propylene stylene block co-polymer (S.E.P.S.).
Now, the s~n~,."~nt of front and rear standing leg gather portions will be 10 e~rlsin~l As described above, when the front and rear sections are to be joined to form an integral abso~b.nl article, it becomes one of h~l~ollant l~uilu.ll~llt~ to maintain the cn~ iec of the gather portions in the crotch s~u,~,u~ t region. Fcrecislly, it is true when the standing gathers are h~uj,l,ol-tted in the article. The simple ~ul~ ,nt of the front and rear sections tends to prevent the standing gather portions from standing up in the crotch 15 s~u~ t region. Therefore. suitahle means needs to be imrlemPnt~1 to maintain the cn~ ;liec of the standing gather portions in the crotch se,.;u.~,l"G"t region.
According to the present invention, such ~,~' are solved by the following means. Prior to joining the front and rear sections, each of the strip .. 1-~-2. for forming the standing gather portions is secured at its lower edge to the topsheet by suitable bonding means, 20 with its upper edge being uns~u~c~d thereto. Each of the strip members extends longihlflin~lly beyond the &l~SOIl..,.ll body to define the marginal end together with the b~ l in the crotch s~;ult;.--.nt region. At the stage when the marginal ends of the front and rear sections are joined to each other to form the tab, selected surface areas of the respective strip members of the front and rear sections are placed upon each other. The selected surface area of each 25 strip member extends transversely to its full width and extends lollg;~ lly from the tap portion toward an inner portion of the front or rear section beyond an outer edge of the al)so.l,cnt body. The selected surface areas of the respective strip members are bonded to each other by hotmelt adhesives.
The triangular honded portion thus formed between the front and rear sections is30 referred to as "a cross-over flap" in the specification for convenience of eYpl~n~tinn The cross-over flap formation causes the length dimension of the upper edge of the strip member to be smaller than that of the lower edge of the strip member. This difference in length d;~ r n~
causes the strip member to stand up from the topsheet to define the so-called standing leg gather.
The formed cross-over flap portion is cnnn~rt~d to the topsheet portion through the tab so that it serves to support the standing gather. Acco~h.cly, the cross-over flap portion has the function which effectively prevents the standing gather from moving a great deal inwardly or outwardly; especially from moving outwardly. In the event that the cross-over WO 94/288~15 216 4 ~ 31 PCT/US94/06230 flap is joined to the aforementiollcd SepaMtOr petal, it also serves to maintain the standing leg gather in a suhst~nti~lly uprb~llt position. Thc cnhs~:~nti~llly upright standing gather defines a partition between front and rear portions of the article so that it serves as a ~ to prevent urine and fecal material from mixing with each other.
In the present invention, the elasticity of the gather is set to the 1.1;.. ;.. ~1.. that permits the inner leg gather to snugly fit to a user's body. As the elasticity hlCI~wc~ the inner leg gather is more likely to yield to the pressure exerted by the ll~ .lt of the user or by the load of body exudates so that the gather expcl;cllces deformation which 5~lhse~ Pntly cause leakage of the body PYud~c s. Suitahle materials for the strip member which forms the inner 10 leg gather include a non-woven fahric havin= suitahle elasticity and flexibilityand an elastic c~.mpoci~o of a non-woven fabric and an elastic material. A typical example of the elastic non-woven fabric is the one ~ lr..~ cd by subjecting a carded web c.~..l~-;..;.-g highlyheat-shrinlcable conjugate fibers of polyesters or polypropylenes to high-pressure water jet and applying heat to the resulting hydroentan~led non-woven fabric. Typical eY~mpl~s of the 15 elastic composite include a composite of a non-woven fabric and an elastic film and an c(~ )o~ile of a non-woven fahric and elastic melthlown fibers. As will be readily ~,.c ~ ~, the concept of the present invention is also applied to the inner leg gather of conventional construction which includes an elastic material in its head portion and a non-woven fabric in its leg portion.
In &cco~lc.. ce with still another aspect of the present invention, there is provided a method for ...~.. r~ l~..h~g an absorhent article which co...~,.;s~ a n~ain body having a waist hole and a pair of leg holes, an elastic waist portion disposed along the waist hole and a leg gather disposed along each of the leg holes. The method CGlllpl;~cS the steps of providing a topsheet, an absorhent hody and a h~rl~cheet for ~ccelTIhlin. a front section, providing a 25 topsheet, an absorhent ho~ly and a h~rkch~et for assembling a rear section, and placing the front section upon the rear section for joining the front and the rear sections to form a crotch region and opposite side regions of the main body.
U.S. Patent No. 4,4~7,408~ c~qs a method for -- - r ~-- ;,.g the l' Ih,.lt articles which places a front section upon a rear section for se.;u.~,...~,..t thereof. This method 30 however prepares an inte&ral pair of front and rear sections before bi-folding the pair of sections lo--~iludinally or transversely, in contrast to the present method which a;,~,...bl~ the front and rear section separately and elimin~tec the necessity of the bi-folding.
Prior to the placing step, waist and leg elastics may be provided along peli~.ies of the waist hole and the leg holes, respectively, to form the waist gather and the leg gathers.
35 A reinforcing step may be added to the above steps to reinforce the crotch 5~u.~ ,.l region.
The present invention further provides a method for . ~ ~ r~ ~ i"g an ~sull~, article which comprises a main body havin~ a waist hole and a pair of leg holes, an elastic waist portion disposed along the waist hole and a leg gather disposed along each of the leg WO 94/28845 216 ~ PCT/US94/06230 holes. The methocl comprises the steps of pro~icling absorbent bodies in predetermined intervals between a lnmyitudinAlly movino first continuous web and a longitudinally moving second continuous web to form a first assembly, providing absorbent bodies in prede~ -,,.;n~
intervals between a l<-noitu~linAlly moving third cnn~inllo~C web and a longihl~linAlly moving 5 fourth con~in~nu~ web to form a second assembly, moving the first assembly and the second assembly in the same direction for introducing the first assembly upon the second ~ lJly, heat-bonding the first and second Accemhliec to form the crotch regions and side regions of the main body, and cuttiny the first, second, third and fourth contin~ollC webs in the heat-bonded regions.
One of the important ndvantages of the present method is that a step of bi-folding a member including a topsheet, a h~cl~ch.~et and an absorbent body in a crotch region is ~oliminAted because a front section and a rear section of an ~so.l~ t article are separately l.l,led before they are joined to each other in a c}otch region and opposite side regions.
Therefore, the present method is capable of eli,n;-,A~;ng the l.oublescll~c alignmPnt of the front 15 and rear sections n~e~innecl by the bi-folding to provide improved process err,- ;&~ and a reduced rate of product loss.
BRTEF DESCRIPTION OF THE DRAWTNGS
Fi_ure I is a perspective view of a first "I.o~l;,..~ ,.1 of an al~sc~llh"ll article in accolda.l.~e with the present invention, partially cut away to reveal the inside ~IIU~IU1~
Figure 2 is a lnnyi~u~lin~l cross ;~;tion view of the a~sc,ll,~.ll article of Figure 1;
Figure 3 is a developed plan view of the ab~oll,c nt article of Figure I with a topsheet removed;
Figure 4 is a partially cut-away pc,~l,ective view of a second e--~l-o~ n~ of anabsoll,~,"t article in accu-dance with the present invention;
Figure S is a longitudinal cross-sectional view of the absorbent article of Figure 4;
Figure 6 is a developed plan view of the àbsolL~ut article of Figure 4 with a topsheet removed;
Figure 7 is a fraymentary l~mgit~ inAl cross-sectional view of an elastic co~
sheet suitable for use in an absorbent article of the present invention;
Figure 8 is a partly cut-away perspective view of a third c --1~1;--- ~1 of an ab ,ulI,~llt article in acco-dance with the present invention;
Figure 9 is a lonyitu<linAl cross-sectional view of the al soll,.,.lt article of Figure 8;
Figure 10 is a developed plan view of the absu,1,enl article of Figure 8 with a topsheet removed;
Figure 11 is an enlar, ed cross-sectional view taken along a line A-A of Figure 10;
Figure 12 is a devdloped plan view of â fourth e,.ll~ollillle.ll of an t~
article of the present invention with a topsheet removed;
Figure 13 is an enlaryed cross-sætional view taken along a line B-B of Figure 12;

2164~31 PC1,vs 94/06230 - - IPEi~lUS 21 JlJN t99S
Figare 14 is a partly cut-away pQ~e~,livci view of a fifth c.l-l)o~lu...,~; of an al~,ll.e.-l article in accordance with the present invention;
Figure lS is a l.)i~ l cross sc~,Lo.ldlview of the ~SO11J~ artide of Figure 14;
Figure 16 is a developed plan view of the at~so~l,~ll article of Figure 14 with a S topsheet ~ ,v~l, Figure 17A is a partly cut-away p~.~c~liv~ view with a m~ifiçd section 17B
a p~ ,d embodiment of a joint col~l~u.,Lol. between a front section and a rear section;
Figure 18A is a parLy cut-away p~ v~ view with a ma~nified section 18B
10 i lln~tin~ another pl~ d c~ o~ l of a joint co~l.u~Lo.- between a front section and a rear section;
Figure 19A is apartly cut-awayp~l~c~ v~,view with a l..a~.;l';~ section l9B
ill~.,l . ~l; l , still another p~ d e- ~h G/l;. 1 of a joint co~ u~Lon between a front section and a rear section;
lS Figure 20 is a partly G'' L~. a~ p ~ v ~ view of still another ~ - ,ho~ of an al~ l atticle in ~c~ ewith the present invention;
Figures 2IA, 21B, 21C illustrate â portion of the ;~h~ ~ article of Figure 20 wherein 21A is a par~y cut-away p~ v~ view ill..~h.~ g a leg gather portion, 21B is a view ro1;-~g a tab portion fonned in the leg gatherportion and 21C is a view i~ -g an angle at urhich the leg gather stdnds up;
Flgurc 22 i8 a partly ~-a~ay pw~CCli~ view of the aL~ulb~ilt article shown in Figure 20 as being in the state before secured.
- Fig~re 23 is a p ~e~ e view with a ~ f;~l section of still another pl~wl~d ~. ~o-l;,.~ of aJoint c~ A~ t-~-- of a front section and a rear section; and 2S Figuro 24 is a schematic flow diagram ill-- A~ an e ~t --g process for m ~ e the first ,~o~ of the s b-- alticle in lcc~ ,c with the present iu~rention.
n~ ) DESCRIPTION OP TE~ PREFERRE~ E~IBC)DIMI~NTS
Figures 1 through 3 i11ustrate one ~ s - of a tapdess ~ ,u,l,w~l ar~cle in 30 â~a :withthepresent ~;O~L lnthed~a~.~, .~f~ enumeral 1 indicatesamain body which c~ 9 a f~ont section lA and a rear section lB. Thoee sections are joined to each o~her by suitable bonding means such as heat-bonding to fonn side ~e~ regions 2a in opposite side regions of the article and in a crotch se~ 1 region 2b in a crotch region of the alticle. Thc main body 1 includes a waist hole 3 and a pair of leg holes 4. An elastic waist 3S gather 5 is disposed along the p~4,h~, of thc waist hole 3. An elas~c leg gather 6 is disposed along the p~i~ of each of the leg holes 4.

~EHl~E~ SHEE7 WO 94/28845 216 g 4 31 -8- PCT/U594/06230 As illustrate(l in Figure 2, each of the front section lA and the rear section lB
each comprises a topsheet 11 formed of liquid permeable and hydrophobic material, i.e. a hydrophobic non-wovGn t:abric, a h~ckch.~et 12 formed of liquid i~ c....edble material, and an al,s~ ,,.t body 13 interposed hetween thG topsheet 11 and the h~rkchP~t 12.
SIt is to be understood that thG lc,p~l.~ls 11, the 1-.1c~ ,t~ 12 and the ~sc,.l,~,.... t bodies 13 are separately ~licposed, respectively, between a boundary between the front section lA and the rear section lB. The front section IA and the rear section lB are ;I~A~Ir ~
from each other until they are integrally joined to each other in SG;UlG111~,nl regions 2a, 2b.
The absorbent article of such structure includes the main body 1 co..Dl.u~,lGd by 10 joining the initially separate, front and rear sections lA, lB in the se.;u..,.~"t regions 2a, 2b.
Therefore, it becomes possible that thG front section lA and the rear section lB may use different materials for any of their respective topsheets 11, h~^kch~t 12 and al)su.l,~.lt bodies 13. This permits the front and rear sections lA, lB to function differently or individually.
In a particular embodiment, the absorbent body 13 of the front section lA
15 """l" ;c~c a highly abso-l,. ,-t element co- ~ a cG-..l .n~ ~t;--n of pulps and super a' I~..t m~t.~ri~lc ~enerally referred to as "SAP"and the abso-l,~nt body 13 of the rear section lB
cc..-~--;s-,s a thin and expansive ahsorbent element, so that the front and rear sections can serve as a urine spot and a fecal spot, respectivGly.
It is possible to exhibit an optimum urine absc,.l,G..l capacity and the capacity of 20 treating fecal material thereof as m.~ntionP~l above, when a topsheet of a hydl~l cl ~ fine-mesh sheet treated to be hydrophilic is used for the front section lA, and a topsheet formed of a hydrophilic coarse mesh sheet is used for the rear section lB.
Figures 4 through 6 illustrate a second çmho-lim~nt of the ~ 1~..1 article in acco.Ja..~ with the present invention. The ahso.l,c,.l article includes a front section lA as 25 c~ Dl~u~iled similarly to the front section of Figures 1 through 3, and a rear section lB which cGlllp~;DGs an elastic CGllll)osit~ sheet 21, as will he he.dn~.rte, described, and an i~sOIl~.lt pad 22 disposed inwardly of the comrr.cite sheet. As illustrated in Figure 5, the ~so.l.~nt pad 22 is rectangularly configured and is sealed at its ~,e.;l,he,;~s to enclose an ~sc.~.~l core 24 within a pouch-like cover 23. Th~ ahsorbent pad 22 is at its one pe,;pll~,.y joined to the dastic 30 c<,.l.~-osile sheet 21 by suitable means such as heat-bonding. The same .~f~ ncc Illlm~r~lc are used throughout Figures I through 6 to indicate the same or similar elements to ...;.~;...;,-r~l~ln~ nry in the explanation thereof.
The elastic composite sheet 21 as is employed to conDl.u-,l the rear section lB is illustrated in Figure 7. The elastic coml70site sheet comprises a heat-sealable, film or non-35 woven elastic sheet 31 tormed of synthetic ruhher, polyu.~ll-ane, styrene-but~-liPn~ block polymer or polyolefin elastomers, and a non-woven fabric 32, 33 heat-bonded to at least one surface (to both surfaces in the illustMted embodiment) of the elastic sheet 31 by a plurality of parallel D~ulc~lllent lines 34. The non-woven fabric, 32,33 provides soft touch to a human WO 941288~5 21 S 4 4 31 PCT/US94/06230 g skin. Preferahly, the elastic composite sheet includes a pluMlity of Chd.)l~CI like spaces 35 defmed between the elastic shedt 31 and the non-woven fabric 32,33.
The absorhent article of such construction can be smoothly applied to and removed from a human hody since its rear s~ction IB comprises the highly elastic co~
S sheet 21, and is capahle of snugly fitting to any human body profiles and of following any movements of the human hody so that it provides better comfort to users during use.
Figures 8 through 11 illustrate a third embodiment of the present ab~
article. In the illustrated emhodiment, side panels 41a are c~-nnr~ctPd to a front section lA to respectively extend from opposite side ends of the front section lA. Likewise, side panels 41b 10 are c~ P~ted to 8 rear section I B to respectively extend from opposite side ends of the rear section IB. The elastic composite sheet is dually layered to form each of the side panels.
Leading ends of the side panels 41a are joined to respective leading ends of the side panels 41b to connect the front section IA and the rear section IB.
A waist elastic 5 is interposed hetween the topsheet 11 and the l)~ l.r~rt 12 to15 forrn a waist gather disposed along a waist hole 3. A leg elastic 6 is attacbed to each of the side panels 41a, 41b.
Because side panels 41a, 41b are elastically stretchable and ~-ll. ' I they are capable of elastically c0upc-atillg with the elastic waist portion disposed along the waist hole to facilitate npplication and removal of the article and provide improved fit thereof to the human 20 body during application.
Figures 1 ~ and 13 show a fourth emhorlimRnt of the present al)so~ rt article. In this L.llbo.li.,.c"t, a front section IA is ~:cemhl~l similarly to the first emhorlimRnt as illustrated in Figure 3 to comprise a l-~ t 17, a topsheet l l, an abso-l~.,.-l body 13, a waist gather S and leg gathers 6. In addition to such ehRmPntc, a rear section lB further includes 25 cuff barriers 51a, 51b. Thesd cuffbarriers 51a, 51b may co~ ise the elastic Co,,,~ c;l~ sheet as illustrated in Figure 7. Each of the cuff harriers 51a, 51b extends laterally from a side edge of the rear section IB toward a center of the rear section to cover the topsheet 11 of the rear section lB. Leading ends of the cuff barriers are respectively contoured to define an opening 52 ll-e.~l,dt~dn. Accordingly, the topslleet 11 and the cuff barriers 51a, Slb of the rear 30 sectiGn lB define therdbetween a pocket co-l----u--icating with outside through the opening 52 for C~ f~ of fecal material.
Figures 14 through 16 illustrate A fifth embodiment of the absorbent article in &CCO~da~æ with the present invention. In this ~mho~limPn~ a front section lA and a rear section lB may be respectively fissd...l,lcd similarly to those of the first emho~limPn~ of Figure 35 3 to respectively include a hackshedt 17, a topsheet 11, an al;so-l,dl-t body 13, a waist gather 5 and a leg a~ather 6. In aclclition, an ahsorh~nt pad 60 of relatively small size is attached to the Se:~UIe~ region of thd tront and rear sections IA, IB. The absorbent pad 60 COlllpl;~S a liquid permeal-le, rectangularly shaped pouch-like cover 61 and an absoll,clll core 62 enclosed WO 9412884~i 2 ~ 6 ~ ~ 3 i PCT/US94/06230 ~

in the cover 61, and is at its one end joined to the se~;uiG,.I.,,lt region of the front and rear sections lA, lB.
In Figure 15, the absorbent pad 60 is illustrated to sit on the topsheet 11 of the front section IA. This configuration helps exhibit absorbent characteristics particularly suitable 5 for diapers for males. The ahsorbent pad 60 may be moved to sit on the rear section lB to provide another configuration more suitable for diapers for females.
As described above, one of the hlll,ol~ t features of the present invention is that separately Acg.~.rnhled front and rear sections are joined to each other in a crotch region and side regions of the article. Generally, the crotch region of the al,solb~,..t article is a spot for receiving a majority of body exudates during a normal use thereof. Therefore, an ~sc,.l~,.l capacity and a liquid-seAling hal~l~ t~listics of th~ article in the crotch region is one of the critical factors in determinin~ performance of the al,soll-cnt article. Since the S~iul~ ,.lt region of the front and rear sections IA, IB is located in the crotch region of the present dl)so.l,~llt article, it is important to assure sufficient liquid-sealability of the article in the crotch region.
The ~soll,~nl article suitable for actual use may be obtained when heat-sealable~lg are used to forrn a topsheet and a bAcL~he~t However, in the event that '-for use are difficult for conventional bonding means to effect liquid-tight sealing thereto, or in the event that al SOI~ articles for certain use require more highly liquid-tight crotch co.l~hu.ilion, particular designs may be employed to join the front and rear sections to form the crotch region.
Figure 17 shows a particular joint ~on~lluulion which provides a highly liquid-tight crotchregionofanab~ ,nt article. InFigure17,atopsheet 11andab~ P-,~ 12ofa front section lA of the article are at their respective crotch ends placed upon each other to :25 define a tab 71A. Similarly, a topsheet 11 and a 1~",~ ,P,. l 12 of a rear sectiorl lB of the article are at their respective crotch encls placed upon each other to define a tab 71B. Those tabs 71A, 71B are first positioned in a confronting r~l~tion~hip, with hotmelt adhesives 72 being carried on the confronting faces thereof, and then heat-bonded to each other by a sc~ ,ll Iine 73. Such a joint coll:.llu~;lion provides his~hlyliquid-ti~ht ~ tu-;~ at a boundary between the front section IA and the rear section lB so that liquid leakage is p.ci~llted under any use conditions of the article.
As illustrated in Figure 18, a reinforcing member 74 may be ~ itinn~.lly provided and secured along a boundary line between the front section IA and the rear section lB to provide improved leakage protection and improved strength against tearing.
Figure 19 shows an alternative emho~lim~nt of the joint con~l.u~ on of Figure 17which also provicles a hi;hly liquid-tight property. In Figure 19, the tabs 71A, 71B are faced toward each other with a separator 75 therehetween. The separator 75 may be formed of a flexible film, preferahly of a heat-sealahle film or non-woven fabric. The sel)dl~lo~ 75 is WO 94/288~15 21~ ~ ~ 3 ~ PCT/US94106230 interposed betwæn and heat-bonded to the tabs 71A, 71B canying adhesives 72 such as hotmelts by a s~.~,c:")ent liné 73. An end portion of the separator extends upwardly from the topsheet 11 to define a projection 75a. The projection 75a partitions the article into front and rear portions and serves as a separating petal which functions to effectively separate urine from 5 fecal material as described above.
As will he readily appreciated any materials or any co~ lions of co..sl.u-;li.,..
enabling the front section IA and the rear section lB to function individuallyas illl-ctr~tPA in the above ~mhsrlimi~ntc are merely exemplary and can be optionally selected in acc(~ e with ~4u;rc.~l~ .lt~ by varieties of usages or applic~tionc.
Fu~tll~.u~ore, when the backsheets of front and rear sections are ~
fonmed of films with different colors or patterns, it becomes easy for users to identify the front and rear portions of the article at a glance.
Figures ~0 through ~3 show an ahsorbent article of the present invention which includes leg gathers. Similarly to the ahove enlho~lim~ntc, the article includes a main body 15 co...~.; ,;--g a front section IA and a rear section lB which are joined to each other by tabs 2b.
In th;s embodiment the article has first gathers 81 each comprising an elastic strip member and second gathers 82 each disposed inwardly of the .u~.~t;~ first gather and c-~y~lic;~g a strip member. The first gathers 81 and the second gathers 82 respectively extend along the Icg hole 4 of the article. For convenience, the first gathers and the second gathers are h~ art~
20 refen-ed to as outer le, gathers and inner leg gathers, respectively. The outer leg gathers 81 can be optionally omitted. In such an eYent, the inner leg gathers also serve as the outer leg gathers.
Each of the inner leg gathers 82 co."~ es a strip member formed of suitably flexible material and extends longitudinally across a crotch region of the al~sc.l,~..t article. The 25 inner leg gathers 82 are laterally spaced from each other a p,~A. t ,.--;--~1 distance to define a c~ ;n~ .t zone therebetween for absorbing or holding exudates therein. The strip member is at ;ts one side end joined to an exposed surface of the topsheet 12 to form each of the inner leg gathers 8 ~.
In accor(lance with one important feature of the present invention, each of the 30 inner leg gathers 8~ stands up from the topslIeet 11 of the main body 1 at a suitable angle during use of the absorhent article. In the following embo-lim~ntc, the standing feature of the - inner leg gather 8~ is effectecl hy shortening the len_th dim-oncion of a second end ~ere;.. n~.
referred to as "a distal end") remote from the topsheet 11 with respect to the length d;
of a first end (hereinafter referred to as 'a proximal end") joined to the topsheet 11.
In a particular embodiment as illustrated in Figures 21A, 21B, 21C, the inner leg gather 82 is tucl;ed in the crotch region of the main body 1 along folding lines which extends divergently flnd upwardly from the ploximal end toward the distal end and for s~u.~ ..l so that a cross-over flap 8~a of suhc~lnti~llly triangular shape is formed.

WO 94/28845 216 ~ 4 31 PCT/US94/06230 ~

While the secured cross-over flap 82a may be formed by tucking the inner leg gather either inwardly or outwardly, it is plcr~ cd from viewpoints of product aplJ~lall-,es and its other utilities to tuck the inner leg gather inwardly so that the cross-over flap extends inwardly therefrom.
S The extent of th~ inclination of the gather 82 is selectively dct~ ,llul.cd by the extent of shortening of the distal and with respect to the proximal end of the strip member.
Referring to Fi~ure 2lB, threc fol(ling lincs are formed to extend upwardly from the proximal end toward the distal cnd of thc strip membcr. The outer and inner folding lines extend upwardly in a diverging relationship toward each other so that two triangles Tl, T2 are defined.
10 These two tri~mgles T1, T2 are defined to be sy.lull~llical with respect to the ;t~ "r.l; ,t folding line L1. Each of the trian~les T1, T_ includes the folding line Ll which bounds the two tri~ngll-~, a line L2 which extends along the distal end of the strip member, and a folding line L3 which traverses thc strip member at a suitable angle with respect to the folding line. These two trianglcs are placcd upon each othcr for securement to form the cross-over flap 82a as 15 above l~lculioned.
Figure 21C shows a triangle T defined by the cross-over flap 82a. In Figure 21C,~-,f~.~,.lcc numeral L0 indicates a base line which collcbl,ol.ds to a top surface of the topsheet 11 to which the cross-over flap 82a is attached. The line L3 of the triangle T defined by the cross-over fl~p 82a is inclined by a predetermined angle ~ with respect to the base line 20 (topsheet) L0. The angle ~ of inclination becomes greater as the length ll;",~ ,. of the line L2 of the triangle T increases. As thc angle becomes greater, a top of the cross-over flap 82a is further spaccd away from thc topsheet l l and is moved further upwardly.
Although it is not rcquircd that the cross-over flap 82a of ~ul~ t;~lly tl;a..,~.lar shape is secured to any othcr memhcrs, it may be secured to the topsheet l l inwardly of the 25 inner leg gather 82. Figurc 22 shows one emho~limPnt of the ~bol~ ll article during use which ;llCol~oldt~,s the cross-over flap therein. By this conbl-u~;lion~ the cross-over flap 82a acts to pull the inner leg ~ather 82 inwardly in the crotch region against the force (shown by an arrow X in the drawing of Fig. 23) exert~l by the leg action of a user which acts to pull out the inner leg gather 82 from thc lesg hole 4. Therefore, the provision of the cross-over flap 30 serves to prevcnt such an inconvenicncc from taking place when the con~llu~lion is applied to the tapeless absorhent article wherein the user inserts a leg into a leg hole 4 from inside of the article.
In an actual production of the al,soll,~ "t article of the present invention, it is possible to use the ploce:dulc set out below. As illustrated in Figure 22, in a stage prior to 35 sc~;w~llcnt of the front and rcar sections IA and IB together at a joint portion lO, the strip members for formin~ thc inner leg ~athcrs 82 are c~-nnPr~P~I at their lower edges to the I l, respecti~cly~ Laycrs 83 of an adhcsive material such as of hot-melt-type are applied on the side facing to; ctl-cr of cach pair of the strip members over a suitable length.

WO 94/2884~ 2 ~ 6 ~ 4 3 1 PCT/US94/06230 The topshects 11 of thc front and rear sections IA and lB arc then forced to contact to each other in the direction of an arrow Al, thereby to bond the strip member pairs by the adhesive layers 83.
As a result, each pair of the strip ...c...bc.~ are conn~rted together to form the S c~ntinllouc le~ gather pair 82. Each of the leg gathers 82 thus formed is c~lm~c~l to the topsheet 11 at its lower edge, and at the joint portion 10 the upper edge is also C""'~F~ to the topsheet. In this co~ u-,lion, thc upper edge of each leg gather is longer than the lower edge~ thereby to stand up the leg gather when the ab~o.l,.,nt article is applied to the wearer's body.
10 Now the explanation is made with lefe.~.. ce to Figure 24 regarding one exemplary method of ~ rS~ ;ng absorbent articles as illllctr.qted in Figures 1 through 3. In accG,d~...ce with this method, a first step of assembling the front section is pe.ru~
cimllltqneouc~y with a second stcp of assembling the rear section. The subsequent third step involves joining the individually assemhled front and rear sections.
First, the first step which ~ccemhle$ the front section will be ~YplqinPd Referring to Figure 24, a first sheet 101 cor.,l,.;shlg a contin~louc web is cl-nt;ll Jo~ly withdrawn from a roll lû2 at a predetermincd constant spced. Meanwhile, a carrier sheet 104 is c~ nt;. --- ~ly withdrawn from a roll 103. A pulp former 10~ treats absc.l,~.ll mqtPriqlc such as pulp to feed f~.. ed abso.l,.,.. t bodies (not shown) of p.cd~t~,... ~ shape to place them onto the 2û carrier sheet 104 at p.cd~te.---h~ed intervals. The first sheet 101 is then placed upon the carrier sheet lû4 carrying th~ absorbent bodies to form a first assembly 100.
An elastic Icg material 109 withdrawn from a roll 108 is attached to a second sheet 107 which is in turn withdrawn from a roll 106 by bonding means which is not shown in the drawing. The second shcct 107 carryin~ the elastic leg material is ".I:~s~lu ..lly placed 25 upon thc first sh~t 101 and thc ahsorhent bodics. A waist gather material 111 will.. l.~.~
from a roll 110 is placed on a bottom side of the first sheet 101 which is then ll~ f~ d to a next step.
The second step of assembling the rear section is pe.ru...-ed likewise the firststep. A second shcet 201 comprising a contin~lo~c web is co .~ o~ly withdrawn from a roll 30 202 at a predct~ .. ;"cd constant specd. Meanwhile, a carrier sheet 204 is c~ ;.. -o,~ly withdrawn from a roll ~03. A pulp former 70~ treats absorbent mq~riqlc such as pulp to feed - p~r~ -cd absorbcnt bodics (not shown) of predetermined shape to place them onto the carrier sheet '~04 at prcdctermincd intcrvals. The second sheet 201 is then placed upon the carrier sheet '>04 carrying the absorbcnt bodies to form a second assembly 200.
An elastic leg matcrial '709 withdrawn from a roll 208 is attached to a second sheet ~07 which is in turn withdrawn from a roll 206 by bonding means which is not shown in the drawing. The second shcet 207 carryin~ the elastic leg material is ~ -tly placed upon the second shect 201 and thc ahsorbent bodies. A waist gather material 211 withdrawn WO 94/28845 2 ~ 6 ~ ~ 3 1 , PCTIUS94/06230 from a roll ~lO is placed on a hottom ~iidc of thc sccond shcet ~01 which is then Ir~lsf~led to a next stcp. Howcver, thc positional rclationship of the second sheet ~01, the carrier sheet 204,the absorbent body and the waist gather material ~11 is reversed from that of the first assembly with respect to the first sheet 101.
S In the above emho~lim~nt~ the first sheet 101 co~ ,lises a non-woven fabric which forms a topsheet and the second sheet tOl col.,l..ises a liquid i...~ .."eabl~ film which forms a bat~kchPP,t.
The first assembly 100 and the second assembly '00 as .,.. r~. ,.. ~ via theabove steps are then placed upon each other so that the absv.l,~,nt bodies thereon face toward 10 each other, and are s~lhs.~quPntly hltluduced into a ~u~Je~onic sealing e ~U;~"~G"t 301 where they are heat-bonded to each other along a crotch region and side regions of the resulting article. It is important in this step to assure that the first assembly 100 and the second assembly ~00 arc correctly aligned with cach other. This ~lignmPnt can be readily effected by ~llcl.rvlliLing the feed spceds of thc asscmhlies 100, ~00.
Atter thc heat-honcliny is complctcd, cutting is effected by a round cutter 302 to form the leg holes, and ;uh :e~luellt cutting hy an cnd cutter 303 separates the bonded assemblies into individual articlc pieces.
In order to m:~nuf:-~tllrc the absoll,~,..t article as illuct-~t~ in Figure 8 which joins the respective side ends of the tront and rear sections by the elastic side panels 41a, 41b, 20 the elastic strip members cv."l ,;s;,.g those side panels 41a, 41b may be pl~,vivu~ly attached to opposite side ends of each of the first and second sheets lA, lB such as by heat-bonding before distal ends of the respective strip members are heat-bonded to each other by the :~U~ .OniC sealimy e~uil,....nt 301.
Alternatively, the elastic waist portion 5 may be ~limAncion-pd so that its opposite 25 side ends extend outwardly from respective side edges of each of the front and rear sections to define the side panels 41a, 41b.
As described above, the al,ic)lbcnt article in acco,J~ce with the present invention comprises the front and rear sections which include individual t-~ , b~ h~,t~
and absorbent bodies, and are joined to each other by suitable bonding means such as heat-30 bonding at a crotch reyion and opposite sidc regions of the al,~o.bc-lt article. This permits the front and rear portions of thc ahsorhcrt articlc to function differently from each other so that the present ahsorhent articlcs are ahle to hc responsive to various needs inrh~ling various configurations for use.
Furthcrmorc, in accordancc with the present method, the front and rear sections 35 are separately ~cc~mhled before they arc finally bonded to each other to form a final product.
Therefore, the present method is ahle to elimin~te the conventional folding step in which the topsheet and absorbcnt body assemhly are folded along a crotch region, and accordingly to e.limin~A necessity of the trouhlesome alignment of side ends thereof during the folding step.

WO 94/28845 ~ 4 ~ 3 i PCT/US94/06230 As a result, th~ present method provides a !reatly reduced rate of product loss and f~ e an overall process control.

Claims

-16-

1. An absorbent article comprising a main body having a waist hole and a pair ofleg holes, a crotch region between the leg holes, opposite side regions, an elastic waist portion disposed along said waist hole and a leg gather disposed along each of said leg holes; said main body comprising independently produced front and rear sections, said front section comprising a first backsheet, a first topsheet, and a first absorbent body interposed between said first topsheet and said first backsheet and a leg gather, and said rear section comprising a second backsheet, a second topsheet and a second absorbent body interposed between said second topsheet and second backsheet, said front and rear sections being disposed with their respective topsheets facing each other and being bonded to each other in the crotch region and opposite side regions of the article.

2. The absorbent article of claim 1, wherein said front and rear sections respectively have portions extending laterally outwardly from the absorbent body and secured in facing relation to each other in said crotch and opposite side regions of the article.

3. The absorbent article of claim 1, wherein said leg gather comprising a member disposed on a top surface of each of said front section and said rear section, said member having a proximal end disposed adjacent to said top surface and a distal end spaced away from said top surface, said member being secured onto itself at a location adjacent to the crotch region where said front section and rear section are bonded to each other.

4. The absorbent article of claim 1, wherein said backsheet of the rear section is comprised of an elastically stretchable and contractible material.

5. The absorbent article of claim 4, wherein said elastically stretchable and contractible material is an elastic composite formed of a liquid impermeable, elastic material and a non-woven fabric.

6. The absorbent article of claim 2, wherein said portions are secured to each other by hotmelt adhesives.

7. The absorbent article of claim 1, wherein said front section and rear section have tabs at their respective ends, adjacent the crotch region and said tabs are secured to each other by hotmelt adhesives, said article further having a reinforcing member secured in the crotch region and extending along a boundary line between said front section and said rear section.

8. The absorbent article of claim 1, wherein a projecting separator petal is disposed along a boundary line between said front section and said rear section in said crotch region for separating solid exudates from liquid exudates.

9. The absorbent article of claim 1, wherein said front section and said rear section are joined to each other by elastic side panels attached to respective opposite sides of the front and rear sections.

10. The absorbent article of claim 1, wherein said rear section further comprises a barrier cuff spaced away from the topsheet to define a space therebetween, said barrier cuff having an opening for receiving exudates into said space.

11. The absorbent article of claim 1, wherein an absorbent pad is disposed between said front section and said rear section, said absorbent pad is joined at one end to a securement region of said front and rear sections so that the absorbent pad is movable between a first position on the topsheet of the front section and a second position on the topsheet of the rear section.

12. An absorbent article comprising a main body having a waist hole and a pair of leg holes, a crotch region between the leg holes, opposite side regions, an elastic waist portion disposed along said waist hole and leg gathers disposed along each of said leg holes; said main body comprising independently produced front and rear sections, each of said front and rear sections comprising a backsheet, a topsheet, an absorbent body interposed between said topsheet and said backsheet and a leg gather, said front and rear sections being disposed with their respective topsheets facing each other and being bonded to each other in the crotch region and opposite side regions of the article, said front section having at least one constituent element whose property is different from that of the corresponding element of the rear section, and said leg gather of each of said front and rear sections being at an end secured onto itself in the crotch region of the main body to define a cross-over flap of substantially triangular shape extending inwardly of said leg gather so that said leg gather stands up from the topsheet.

13. A method for manufacturing an absorbent article which comprises a main body having a waist hole and a pair of leg holes, an elastic waist portion disposed along said waist hole and a leg gather disposed along each of said leg holes; said method comprising the steps of:

providing a first top sheet, a first absorbent and a first backsheet and assembling them into a front section with the first absorbent body between the first topsheet and backsheet;
providing a second topsheet, a second absorbent body and a second backsheet and assembling them into a rear section independent of the front section with the second absorbent body between the second topsheet and backsheet;
moving said front section and rear section concurrently in a substantially common direction with their respective first and second topsheets in face-to-face relationship; and placing said front section upon said rear section with their respective topsheets facing each other and bonding selected facing portions of said front and rear sections together to form a crotch region and opposite side regions of said main body.

14. The method of claim 13, wherein prior to the placing step, waist elastic materials are provided along respective waist hole peripheries of said front and rear sections for forming said elastic waist portion, and leg elastic materials are provided along respective leg hole peripheries of said front and rear sections for forming said leg gather.

15. The method of claim 14, wherein during said placing step, the leg and waist elastic materials are provided upon the front and rear sections in their stretched state for forming said leg gather and said elastic waist portion, respectively.

16. A method for manufacturing an absorbent article which comprises a main body having a waist hole and a pair of leg holes, and elastic waist portion disposed along said waist hole and a leg gather disposed along each of said leg holes; said method comprising the steps of:
providing absorbent bodies in predetermined intervals between a longitudinally moving first continuous web and a longitudinally moving second continous web to form a first assembly;
providing absorbent bodies in predetermined intervals between a longitudinally moving third continuous web and a longitudinally moving fourth continuous web to form a second assembly;
moving said first assembly and said second assembly in the same direction and placing the first assembly in facing relationship upon the second assembly;
bonding said first and second assemblies in selected areas to form the crotch region and side regions of said main body; and cutting said first, second, third and fourth continous webs in said bonded regions.

17. The method of claim 16, wherein prior to the bonding step, waist electric materials and leg elastic materials are provided between said first and second continous webs and between said third and fourth continous webs along areas which will become the peripheries of said waist hole and peripheries of said leg holes, respectively for forming said elastic waist portion and said leg gather.

18. The method of claim 17, wherein the moving step includes placing elastic sheets for side panels between the first assembly and the second assembly.