CA2175571A1

CA2175571A1 - Stretch-activated elastic composite

Info

Publication number: CA2175571A1
Application number: CA002175571A
Authority: CA
Inventors: Migaku Suzuki
Original assignee: Individual
Current assignee: Paragon Trade Brands LLC
Priority date: 1994-01-18
Filing date: 1995-01-17
Publication date: 1995-07-20
Also published as: MX9602853A; WO1995019258A1

Abstract

A stretch-activated elastic composite (20A, 20B) comprising: a non-woven fabric (21, 22) having a potential elongatability of higher than 100 % in a predetermined direction, and an elastically recoverable, elastic sheet (11, 12). The elastic sheet in its unstretched state is partially bonded to the non-woven fabric in its unelongated state. The elastic composite exhibits, per unit width of 5 cm: a stress of lower than 1000 g at 30 % stretch; a stress of higher than 400 g at 100 % stretch; a breaking point of higher than 400 g and an elastic limit of higher than 200 %. The elastic composite after being stretched at a rate of lower than 200 % exhibits, per unit width of 5 cm: a stress of lower than 500 g at 30 % stretch and a stress of higher than 100 g at 100 % stretch. The elastic composite after three repeated cycles of 150 % stretching and relaxing exhibits an elastic recovery rate of higher than 60 %. The elastic composite of the present invention provides excellent performance in elastic recovery and a soft surface touch to a human skin, and is best utilized in elasticizing an article portion which is brought into direct contact with the human skin.

Description

`~ WO 95/19258 PCT/US95/00505 STRETCH-ACTIVATED ELASTIC COMPOSITE
Field of the Invention The present invention relates to an elastic cvl-q~v!.;'e which Colll~Jlib b a non-woven fabric and an elastic sheet, and which e~hibits e~cellent pe,ru -e in elastic recovery and a soft 5 surface touch to a human skin. The elastic .- . can be ad~ g~u~ly utilized in ~'- ~ g an article portion which is brought into direct contact with the human skin during use, such as a sleeve portion of a medical gown, or a waist portion or a crotch portion of a sanitary article.
~a~.kpround and SUmmarY of the Invention In recent years, d ~ ''^ articles, ;,.rl,.rl ~g medical articles and sanitary articles, etc., 10 have widely used elastic material to improve the fit to a human body. Particularly, infant articles utilize a CO...Ilvb;tc of an e1astic sheet and a non-woven fabric much more frequently than an individual use of an elastic sheet. The co...l,osite of the elastic sheet and the non-woven fabric is used ~ g the elastic sheet to exhibit its elastic property and the non-woven fabric to provide improved surface structure and reinfo,uGll,.,nt of the elastic sheet.
15 A typical example of such an elastic co.. ~ ;tr is a three-layer co. ~pO~ called S.M.S.
(5pl~nh~ nAAA/meltblown/cr~ nA~d) which is .licrlQs~Ad in U.S. Patents Nos. 4,663,220;4,652,487;
and 4,720,415. This c~ is ~ cd by a method called S.B.L.(Stretch-Bonded 1 ~
wherein the elastic sheet is first stretched and is in its stretched state bonded to the non-woven fabric to form the COl.ll)Obitc upon release. The CO ~ r ~u --r~ d in acco,~' ~e with this method 20 has a stable range of elasticity and neither expands beyond the range nor breaks during a normal use since its ~ n limit cG--~nds to its stretched range during r C. However. the c4 ~l~c;l~A disad~, g~ubly uses more of the non-woven fabric than rnay be noce~.~ and is bulky so that it is not we11-suited for a high-speed CG~ .al proAurti<~n Japanese Patent No. 4-281059also discloses a method for directly ~ - g~ fibers into 25 an elastic net, which is however costly. In order to remedy these dl~a~,~, an attempt (EPC No.
556,749)has been made to bond an el~ E non-woven fabric to an elastic film on line to form a c . ~- of,-' -l like cu,~l~u.,lion.
Japanese Utility Model No. 3-39509discloses an elastic c~. .po~ which is ~ t~uct~d by hydro v' 1" a web co...~,.ibing staple fibers and a non-woven fabric directly formed of 30 ll.------pl~.~ jr ,'~ :~. Inorder forthe C~ ;lA tohave ~ t~ ility of higherthan 70%,itis d~cr ibed that those staple fibers for co. .t;l~ lg the web need to include fibers which slightly crimp upon ~rli ~;on of heat or split fibers which split into fibers of finer than 1 denier.
The above conventional co~roci~es are capable of ~ I; g over a wide range from abreaking point of the non-woven fabric to a breaking point of the elastic sheet. Their critical points 35 however create difficulty in de-cigning product and defining its specifications. It also leaves users with ;,..rr..~;...., knowledge for proper use since they do not know at what point the co- ~l.o~ breaks.
An object of the present invention is to provide a highly ~ uulive~ e~o.~a - r~l and f~nrti- ~l elastic co...~osile which utilizes individual properties of a non-woven fabric and an elastic SU~STITUTE Sl IEEl (RULE 26) sheet in c nn Another object of the h~ tion is to provide a method for : ~, such an elastic c~
In accc.,~ce with the present invention, there is provided a ~ tcL ~ ti~ated elastic c . which c~.--y.,;- s a non-woven fabric having a potential ~ _ t lity of higher than 100%
5 in a biased direction, and an elastic sheet having an elastic recovery rate of higher than 60% and an elastic limit of higher than 200%. The non-woven fabric in its ~ t ~ state is partially bonded to one surface of the ~I.et~,Lcd elastic sheet in s~u,~nt regions. The elastic co- y~ :~ e~hibits, per unit width of 5 cm, (1) a stress of lower than 1000 g at 30% stretch, (2) a stress of higher than 400 g at 100% stretch, (3) a breaking point of higher than 400 g., and (4) an elastic limit of higher than 200%. The elastic cc y~ ; after being stretched less than 200% e~hibits, per unit width of 5 cm, (1) a stress of lower than 500 g. at 30% stretch and (2) a stress of higher than 100 g. at 100%
stretch. The elastic c~--y~ t after three repeated cycles of 150% ,l,c ' g and rela~ing e%hibits an elastic recovery rate of higher than 60%. ~Strain"as used herein means the amount of . ' '1, - of the rnaterial when a ~l.~l~ng force is applied. ~Stress~ is the force applied to produce the strain.
In ordAr to optimize the elastic c _ r~ '-A structure in acco~ with the present invention, it becomes i~o~b"t to combine respective chara~tf.ictics of the non-woven fabric and the elastic sheet thereby irnproving their r~ l,~11y. Since the elastic sheet may be e~pensive relative to the non-woven fabric the addition of the non-woven fabric thereto further improves the cost/~.f~ ratio of the elastic co..~l.o~;lr ln a~A~ D~IJ ~~ with the present .. ~. ~ nn the designs of the c ~7^ non-woven fabric and 6~1~xti~ ~ of the bonding method provide a wide range of selection of the elastic sheet and permit the elastic sheet to fully e~hibit its desired r ~cl -' ty.
(1) The c . bility of the non-woven fabric enables the elastic c ~ . - which is not elastically ~ ~ -')If~ in a normal cn - I:f;f~.~ to have the property that it is ti~_ d by c . to 25 become elastically s~ A and cA~ t bl-.

(2) An ~" ~~ 'e, hydro ~ d non-woven fabric is selectcd. A suitable selectionof its e ,' . ' - - enables the resulting non-woven fabric to have good c, ~ ~ity as well as two-phase c . ~ y which creates a second increase in stress from a certain point.

(3) S~~u,~ t regions for securing the elastic sheet to the non-woven fabric are 30 provided to e~tend ~ ly to the c, ~'- direction of the elastic ca r~ ~ SO that the .~.e~.ll regions provide less ~c ~ to the _~ ' 'lity of the elastic ~--y~

(4) The s~.,e~nt regions provided between the non-woven fabric and a top surfaceof the elastic sheet are staggered from the ~~ ,~.,l regions provided between the non-woven fabric and a bottom surface of the elastic sheet to prevent those top and bottom S~UIC regions 35 from ~,~e l~.p;~g each other. This prevents creation of defective ponions. F~r` g funher, where heat bonding is used some '...;lll~ may occur where heat is applied. By ~l~g~_,~g, as df-~such btittl which may be undesirable does not e~tend through the c~ . ~

The above c~nr;~'- fnc in decigni~ the elastic cc~ y~c:ly coliD~ ion enable production of the elasticOlly recoverable, elastic co..y.o~ which has e~cellent ~ . ' lity under low Dtrain.
The present i..~. ~ further provides a method for r ~ an elaDtic c~ . -S having the above~deccrih9~ f~- iDlics. This rnethod willbe now a: "' -d in detail with ,ef~,.~ to the r~ . ~i. g dlo~
Brief Description of the DraWinFs Figure 1 is a graph showing S-S (stress-strain) curves of an elastic . . - in - e ~' -e with the present invention.
Figure 2 is a graph showing S-S curves of another elastic cc y~,~ in r : ' - e with the present invention.
Figure 3 is a graph showing S-S curves of the elastic ~ . - when Dl~ at a selocted rate and released.
Figure 4 is a graph showing S-S curves of the elastic C~- y~f ~ 1~ when Dl,~;t ' - ' at a rate 15 different from that of Figure 3 and released.
Figure 5 is a graph showing S-S curves of the elastic C4--y'5~ 1~. when stretched at a rate different from that of Figure 3 and released.
Figure 6 is a graph showing S-S curves of the elastic c ~- when bl.~ ' -' at a rate different from that of Figure 3 and rele_sed.
Figure 7 is a graph showing S-S curvos of the dastic ~- ~ when Dtl~ at a rate different from that of Figure 3 and released.
Figure 8 is a graph showing S-S curves of throe different non .. J._II fabrics hydro-by regular means when they are stretched both in MD (machine di.~ ~ ) and in CD
(croDs direction).
Figure 9 is a graph showing S-S curves of the non-woven fabric used in the present when stretched both in MD and in CD.
Figures lOA, lOB and lOC are ~~ ic cros ~lional views respoctively il~
~r m _ ' of the dastic sheet and the non-woven fabric in a ~ ~ ' - - with the present ~
Figures llA, llB and llC are .~ plan viewsill g e~
p.~ - of ~. . regions in the elastic C~ ;t~ of the present iu;~
Figures 12A, 12B and 12C are .~ vt; plan views ill~ Dll g e~
of r- ~ t regions in the elastic . ~ ', of the present invention.
Figure 13 is a plan view illl~Dl~alil g an e~emplary ol~ l of s~ regions in the elastic cc. ~ ;'e of the present invention.
Figure 14 is a pl n view ill~ t;..g another e~.rrlplgry a ~ t of a~u~ regions in the elastic co.,.~oDile of the present ~. f)n WO 9S/19258 2 1 7 5 5 7 1 PCT/USg5/no50:.

Figure 15 is a plan view ill g still another e~r~l~ry P of an svvu.v~.~vnt region in the elastic colu~silc of the present invention.
Figure 16 is a graph showing results as ~ ~,d with regard to the ..,' -', between tensile strength of the elastic ~ . and process I . vs at which the elastic 5 . , - is heat~
Figure 17 is a pe.D}~Iive view ill ' g an ~ article which -- ~,v...~ the elastic . , - of Figure 13 as its side panel.
Figure 18 is a graph showing S-S curves of the elastic cr. y~ le as prepared in EAample 1, the elastic sheet and the non-woven fabric as used in p.., - g the elastic c ---r - of EAample 1, 10 respectively, when they are stretched in CD.
Figures l9A, l9B and l9C are e~ plan views illuDll ng surface sl~vt~vD after the second-stage t.. of EAample 3, after the third-stage t.c ~1 and after the fourth-stage l.~ t, respectively.
Figure 20 is a grapb showing results of a three-cycle test which repeats the 150% stretch 15 and release of only the readily sl. ~ portion of the elastic C4~ 0~ as prepared in EAample 3.
Figure 21 is a graph showing results of a three-cycle test which repeats the 150% stretch and release of only the hardly stl~ portion of the elastic c , as prepared in EAunple 3.
Detailed Descri~ion of Plefv.lvd Fl L_ ' First, e ~' is made l~.ld~g d.`'t~,h - t;~tation. Figures 1 and 2 show typical S-S
20 ( Stlv_) curves of elastic c , - in ~ -e with the present iuivlti~>~. Initial stretch of the elastic c~--y~ causes the elastic sheet and the non ~.J~vl fabric to vAIh ' ~e their structure changes at the same time so that the elastic , ~ shows a .~ high stress. Once the dastic c~--y.r.-;~, is initially sl.v ' -d, the non-woven fabric has already sl~ ~ ~ and eAhibits slight ~v - -- to a second stretch so that the elastic cc.--y~ ' ~'ly eAhibits the elastic 25 ~' of the elastic sheet at a second stretch, and similarly at a third stretch and stretches i' ~Çt.,.. The 1l r~ -e of such a p~ willbe referred to as sl-vtvh a 'i~. in this -r ~
Another , feature of the sl~etch ~ ~t ti is that the elastic ~ , - - eAhibits its ~ .y within ranges de~ ' ~ upon Dl~vtchiJlg rates, as illustrated in Figures 3 through 7.
F.~ g further, Figs. 3-7, respectively, show S-S curves for an elastic ~ similur to that depicted in Fig. 1, but with the strain depicted being 50% (Fig. 3); 75% (Fig. 4); 100%
(Fig. 5); 125% (Fig. 6) and 150% (Fig. 7). Acco-.' ,'y, when the elastic ~ , is applied to a user's body, it elastically stretches and ~ within a range cllci r ' g to .~ of the user's body so that a fleAible and effiri~nt fitting structure can be provided.
The sl.v~h ~ ~ t; . in some cases, might occur ~ rslly when the elastic .e , - attached to a final product is stretched upon wearing. However, it may be ~' b'- that such stretch-activation be done either prior to or during the production of a product using the ~ , - For instance, in an ~-e l~vnl product using the elastic cs q~ for a waist gather, the 2 1 7~J71 WO 95/19258 ` PCT/US95/0050:~

_5 following two cases can be conD,d~ ,d: (1) previously ~hGI~L activated elastic Co--q~ P- is used; or (2) Dtl~tch ~ ti./ation of the elastic CO~ ~'.;h is done during production process. In the fonner case, there can be a problem in storage and/or l~ nn of the rnaterial which becomes bulky. In the latter case this willbe less of a p.-'' During the p,.h~ of a product using the elastic 5 -- . - which has not baen plG-io~ly sl,_t~,h ~ a roll having deep CCill~ ~, ~ or grooves in its ~ surface rnay be used in the p~udu~;lioll line for acL_~i. g partial stretch in the elastic In such case, attention needs to be paid to prevent damage to the surfaces of the non-woven fabric and elastic sheet.
Such a stretch-activated elastic c~ p,cf~ l~'y shows low stress and rapid increase 10 in ,~ - as it e~ceeds a certain range of Dh~t~,h;ng rate so that it stops Dll- ' g before it breaks. In other words, such CO..q.Q~ shows low ,~ -~ to Dl.~tcLil.g in the activated range but at the upper sl.et~Lug limit it shows a rapid increase in ,. -e to stretching.
It is further i~ i that the elastic cc n~ e ~ r its elastic ' iCY even after being stretched and released ,e~ 'ly. The i~.i and basic cl~ ;r of the elastic cn--q~-:~A a~.diu~ resides in its showing of low residual strain.
The cl~u;h~i~lics of a preferred ~Amk~im~n~ of the elastic C~ J- ~-~ of the invention now will be described.
The following results of luc~ul~ _nlD for physical cl-~ CQ were done acco,.liug to methods s~ ly used in this field of industry and based on the JIS (Japanese T- ' -20 S ' dD) ~ dD. Major points of the ~.uc are given below:
(1) Samples to be tested Width: 5 cm Length: 15 cm (2) ~ c cn~ inn for S-S curves Chuck dist~nce: 10 cm Loading speed: 20 cm/rnin (3) Cycle tests Loading and ~ '- - ' g cycles are repeated three times at 150% stretch and the h~ . - curves are c~ -' Stress values are read at 30% and 100% from the final .~ g 30 point of the ~ ~ - curves. Between the cycles an ease time, in which all loading is released, is piven, as shown below:
1st Me~u-c~ ,t -- first S minute ease time--2nd M; C~lt --second S rninute ease time -- 3rd MA c~c~t third S minute ease time. The hysteresis curves as shown in Figs. 1 and 2 relate to this cycle. Line A shows the first loading cycle; A ' shows the recovery during the first 35 ease time; B shows the second loading cycle; B ' the recovery during the second ease time; C the third loading cycle; and C ' the recovery during the third ease time.
The elastic cc.--q~ of S cm wide is sampled to measure a S-S curve during it_ first cycle of stretch and release which shows the following desirable cl~-- f~ 'C, (1) Stress at 30% stretch This shows the initial stress against stretch, which co.,~,,unds to the first . ~n upon using. A 30% stretch is selected as an indicator, showing the initial stretch l~ since it is 'y used in the fiber industry. This value should be selected carefully because too large an 5 initial stress willcreate too tight a feeling. In G.~ -e, a desirable value is not more than l,OOOg, p~ f "y 800 g and more p,ef ly 600 g.
(2) Stress at 100% stretch This is the stress - e - .~ for stre~ ~ v on, and may vary with the: -- 1; - of usage or degree of stretch upon using. In general, the elastic ~- . of the present 10 h~ displays its features at a highly stretched c~ and will usually be used over 100%
stretch, so that a stress at 100% stretch is selected for an evaluation point.
The elastic ~ , of this i ~tio.. should have 400 g or more stress at 100%
stretch, yl~f.,. ' ly 600 g, more p.~,f~,. ' '~ 800 g stretch in order to display the sl.et~,h P ,ti~
product, thereby . ' g desirable shetch ~ vation by stretch at one time.
(3) Stress at a breaking point A sufficient stress is usually 400 g or more, but security against L ~ l break down will be increased when the stress is higher than 600 g, because one can more essily feel the ,., -e p.~ g the limit of stretch.
Such elastic c~.~ yO~i~G will have a very low III~UI~ stress value after stretch-r '~ ~n For rA~- . '-, after being stretch P ~ v at 150% stretch, the stress lower than 150%
stretch willbe QiOPrifi- 1y de~ sed. Such decrease in stress against stretch is d~;. 1 ~e in viewof the objectives of the usage of the co..~ of the present invention.
Desirable p~u~ tics of an elastic ~~ . -- ^ of the present i..;~t.(,~ at 150% stretch at a second S-S curve -- c are given as follows:
(1) Stress at 30% stretch The stress should be less than 500 g, p,Gr~, ~Iy less than 400 g, and re pl~,f~lessthan 300gfollowingstretch-activation. Byselecting suchvalue,~Jl -lly !--~----rJrl '1~ high co.. y.G~iu., on the body can be avoided when the elastic co ~ - is used, for . '~, in products for infants.
(2) Stress at 100% stretch After sl.et,h ~ 5v the stress at 100% stretch will become O 5 ~y lower to rnake it easily stlJ ' ~ , while providing a suitable .~ ~ e against stretch to provide a holding fit to the wearer. The ...;..;...-- - stress is higher than 100 g, pl.,f~ bl~ higher than 200 g.
A second S-S curve - . shows the following ' ~' islics.
(1) Stress at 30% stretch Crnr~ ^nng its cul.rl hility to a user, the stress is pl~,f~ bly less tban 500 g, re preferably less than 400 g.
(2) Stress at 100% stretch 2 1 7s57 1 WO 95/19258 PCT/US95/nOSOS

The stress do~,~s by over 100 g, , -~d to the first -- ~,u~nt.
It is further ilu~ll~l that the elastic cc. q~;l e~hibits a high elastic recovery rate, - and L~.. dillgly a low residual strain value. In evaluating its pe~ru -e in elastic recovery, the elastic recovery rate generally is - ~,d after three repeated cycles of 150% stretch and release.
5 The elastic recovery ratio is d ~ A by a review of the last l~,tul~& point (Pl) on a curve, such as shown in Fig. 2, against the starting point (P0) against the whole elastic ratio. For _ . 'e, o g the Pl point is at 30% for an elastic ratio of 100% the recovery ratio is rol ' '~ by the following formula:

10 Recovery Ratio = 100- Pl - P0 ~c 100 100- (30/150 x 100) 80 (%) The desirable elastic recovery rate is higher than 60%, pn,f~,. bly higher than 70%.
G elements of the elastic ~ - having such elastic recovery now will be ~; , ' - ' The elastic sheet to be used p.~r ~y is selected from -l~ having ,h~ lity of higher than 20% and elastic recovery of higher than 60%. Materials having such '~ ~ t ~ c 20 include foams such as of 1.,. ' ~ or rubber late~ces; synthetic rubber films such as of ;~op,~es or t ' - sqrene-type ~'- ~- films such as of SIS (stylene isoprene stylene), SEBS (stylene ethylene ' ' - stylene), and SEPS (stylene ethylene p,v~"lenc stylene); polyolefin e ' -- films such as of EVA (ethyl vinylacetate), EMA (ethyl methyl acrylate), and EPDM (ethylene p.u~"' ~
diene t~ ol~ ); and ' ' '~...u a' no~ J.~ - such as of pol~l ~ ' e, SIS (sqlene 25 iio~ ,n stylene) and SEBS. The elastic sheet more p.~,f~,. 'Iy c p.;s~s a film, net-like f~ -or meltblown non-woven, formed of ~ A styrene-type r '- such as SIS or SEBS, or blend.'- thereof.
The non-woven fabric, another -~element of the elastic C4 q~;~P of the present invention, will be now C~ A
The most suitable p~ tly known ~ ~ fabric for use in the present ~ tion is a hydro _ ' - ' or , 1- x d non-woven fabric, p.~ ~ "y having high ~ - lity in the mschine direction (MD) or in the cross-direction (CD). The non-woven fabric having high CD-y can be obtained by hydro . ~' " a I ~ ' -lly oriented, parallel carded web which has a high MDICD ratio, i.e. the fibers e~tend pl~A~ ly in the machine direction. The 35 non-woven fabric having high e1~nga'~bility in MD can be obtained by hydro; g' g a randomly oriented fibrous web CO q ~ g highly ~h-inb 'l- fibers, u~,ræd,l.g the ~nt~ngl~ web in MD and drying before it is treated to shrink.

WO 95/19258 PCT/USg5/00~05 Such MD e' ~ ,, ' lity or CD el~ ~ lity iS pler '~ higher than 100%, more plef~ y higher than 200%.
The e)rn,, ' li~y of the non-woven fabric allows the non-woven fabric to follow the action of the dastic sheet when they are c ' -' with each other.
S The non-woven fabric has another iu~rl cl~_ ~ c as well as it,s e'~ y.
As the ~1 ~ of the ~.J~U fabric e~ceeds a certain e~tent, the non-woven fabric starts showing ,~ e to further e' ,, r~n thereof.
For ~ Figure 8 shows e~mrl~ry CD and MD Stress-Strain (S-S) curves of three different non-woven fabrics noted Nos. 1, 3, and 5 which are l~,~~ prepared by hydro-10 e g' g normal parallel webs by conventional means. As apparent from Figure 8, these non-woven fabrics are highly cli ~le in CD, and acco..liu~ly elongate easily in CD within elastic limits thereof. No .~ appears when each of the non-woven fabrics e~ceeds its ehstic limit before it finally breaks.
In contrast, a cp~ ed non-woven fabric (which also may be l~nown as a ~hydro-15 : g'-d non-woven~ or a ~water jet e '^~ non-woven~) for use in the present iu~ - shows rapid increase in stress at about 2009G stretch as ill ted in Figure 9. With the stress -d, the non-woven fabric ,c ~ to elongate until it breaks at a breaking point (about 260% dretch).
This second-phase increase in stress at about 200% stress acts to resist breakin& before the non-woven fabric finally breaks. It is desirable to select physical properties of the non-woven fabric so 20 that the second-phase increase in stress takes place pl~,f~ 'ly at higher than 150% stretch, re p,~f~ at higher than 200% stretch.
In order for the non-woven fabric to e~chibit such cl~nct-~;clics~ the fibrous web c- ~ ~ and the c~nA ~ - for hydro _ ~' thereof need to be selectively e ~ ' ~ ~ For .e . le, tne following~- ..J~ fabric me~ts such l~
(1) Web e ~1 ~lion - Relatively shOn staple fibers of 25-45 mm long are mi~ed with Ic~ long staple fibers of 45~0 mm long to prepare raw staple fibers.
- Fibers are funher mi~ed therein which are capable of ~ "p to crimp.
(2) SPlecti.~n of cnnA~ for hydro ~ ~' Hydro-jets from fine nozzles integrally entangle fibers in the web . u~lion over its whole area, and l' - e~rt~ hydro ~ the web at ll .._.~ intervals. For e~ample, three parallel rows of the nozzles are disposed to hydro ~ ,'^ the fibers in three stages.
A first stage nozzle L~t~,.... .....................Ø15 mm 0 nozzle pitch : 0.5mm water pressure : 30 kg/cm ~

A second stage nozzle diameter: 0.15 mm 0 nozzle pitch : 0.5mm ~ 1 75~7 1 -WO 95/19258 PCT/US95/005n5 g water pressure: 50 kg/cm 2 A third stage nozzle .l.~ll.cte.. 0.20mm 0 nozzle pitch : 1.0mm - 5 water pressure: 60 kg/cm2 A -r l--ed non-woven fabric having a striped pattern is obtained under the above The elastic c~. y.n~ of the present i.~ , - an e!~ e non-woven 10 fabric bonded to a top surface or to top and bottom surfaces of the elastic sheet. Although the bonding method is not limited to a specific one, different bonding methods rnay cause the resultant elastic CfJ ~ to have different ~ t~ s Regardless of the selected bonding ' - ', the following factors become i..
(1) The non-woven fabric is bonded to the elastic sheet so that the readily e'~
15 direction of the non-woven fabric is brought into av~ with the readily l~IJ~ ~ ' ~~ direction of the elastic sheet.
(2) The bonding is made to form s~u.u~nt regions in a selected pattern so that it does not disturb effective d~ ~ . of the - ..J._Il fabric and effective ,tl.i ' e Of the elastic ~heet. To this end, it is ~ that the ~c~l regions are arranged to define as srnall in 20 number and area as possible in the readily e'~ v ' Ir direction. Such bonding can be easily rnade by distributing ~.,.~i~nt regions ~ f 1"~/ in the range of 90 ( ~ 10) with respect to the readily '^ direction of the non-woven fabric.
(3) When - .~J en fabric is placed on opposite surfaces of the elastic sheet, thselective p.ov - of the ~w. regions .~, - ti~ betveen the one - ..J.~ fabric and the 25 elastic sheet and between the other J._~I fabric and the dastic sheet greatly affect the elastic .' of the form~ed elastic , - In the dastic - . - c , t ~ having the elastic sheet flanked between two non-woven fabrics, the elastic sheet rnay , one sheet of an elastic film of 50 ~an thick or two sheets of an elastic film of 25 ~ that the ~ ' '-L ~ of the elastic sheet is selected to bt 50 ~rn. However, it should be .~c~v,-: - ~I that 50 ~rn is 30 used as an e~ample and other ~h G~ may be used as well. Figures 10A, 10B, and lOC illustrate three typical ~' ~e c~ for, ' lg the elastic sheet and the non-woven fabric.
In Fig. 10A two elastic sheets 11, 12 each having a i' ' of 25 ~rn are bonded at._WCi regions 3 to two non-woven fabric sheets 21, æ, .~,~li~ i~ to form two elastic ~ ~ . - - 20A, 20B which are placed onto and bonded to each other by bonding the two elastic 35 sheets 11, 12 wch as by hot pressing as in region 4.
In Fig. 10B two elastic sheets 11,12 each having a l' ' of 25 ~rn are placed andbonded between the two non-woven fabrics 21, 22 through s~;ul~ regions 3 wch as by hot pressing.

WO 95/19258 2 1 ! 5 5 7 I PCT/US9S/00505 In Fig. lOC an elastic sheet 13 of 50 ~n thick is flanked, or; -l - d, between two non-woven fabric sheets 21, 22 and bonded thereto at s~u~c.,.~ ,lt regions 3.
An S-S curve is ~as.--cd for each of the c ' u~;lions illustrated in Figures lOA, lOB, and lOC. Each c~n~l,ulion is stretched by 100% and is L~ released to measure a length S of the ~ , ~'on for c~ with its initial length prior to ~t~ g. Better elastic ,~.u.;~
are observed in lOB than lOC, and in lOA than lOB respectively.
In Figure lOA, the s~u~nl regions 3 of a first set of the elastic sheet 11 and the non-woven fabric 21 are arranged to be .,,E_.~d from the ~u,c~,t regions 3 of a second set of the elastic sheet 12 and the non-woven fabric 22 so as not to overlap each other. The ~w.
10 regions 3 upon which tensile stress is ,.~ - _ d are arranged in different lc between a top and a bottom of the elastic c~ ilc so that the formed elastic ~ ;tt; has a relatively high tensile strength.
The industrial process for ~- ' ' g two sheets of a relatively thin r ~ lPd , ~ -to form a both-sided cc y~ e also i~".,.~ s production err.. ,~ . Fq~i~lly when pol~ ,e..c-15 type ~' films such as SIS or SEBS are used for the elastic sheet, the stable both-sided c~--q~ can be readily r ~d by simply placing the film surfaces of the two Cf~ q~L t~,C
onto each other and hot-pressing them since those films are highly ~ ''- onto themselves.
This greatly improves p,olu. livity and also provides a cost-saving result.
g the ~ 3~ -d bonding of the elastic sheet and the non-woven fabric, both 20 the elastic c~- y~;le c ~:tio.. having the non-woven fabric securely placed upon one surface of the elastic sheet and the elastic: . - ' c ~lion having the - ..J._~ fabrics securely placed upon .~ c top and bottom surfaces of the elastic sheet as illustrated in Figures lOA, lOB and lOC are ill ~ d to have the s_w~nt regions 3 which respectively e~tend in a band-like rnanner in a direction ~ to, ~,~.f~ at angles of 90 ( ~ 10 ~), with respect to the readily ~ hl- and sl.c ' -''- di,~ ~' of the non ~o._,. fabric and the elastic sheet.
The band-like ~w~ regions may secure the non-woven fabric and the elastic sheet entirely over a ~ifiPd area. ~'' 'vcl~/, the band-like s~u,c~"t region may ~ a plurality of s~cu,~ t 9c~ arranged in a row toward a selected direction, such as a plurality of dots or line O - d -'- ' ' d in a d- ' ~'- F ~ m3nner over the ~ifiPd area.
Figures 1 lA, 1 lB and 1 lC illustrate typical P~ x of the F ' ' - ' rows each c- . e a group of s~u,~ sc~ arranged at intervals. In Figures llA,each of the --- e 3~v ~ 31 c~ - a ,elati~,al~ short line segment. The ~ n ~ v ' 31 are arranged at suitable intervals in rows ~ g in a direction ~~~' ~ '' lly ~ to the readily '-L'e direction of the elastic co--~ to define a plurality of rows 30 of s~. ~ ' BCG
35 e~ in parallel to each other. In Figure l lB, each row 30 of s~,. ~t ~_ ' ~c . ' - a plurality of ~ -,_nt s~ 31 which each cr .p~;~ c a line segment and e~ctends ~LI ' lly transversely to a l~ g-lu~ direction of the row 30 of s~iw~ ,.t ~'G~ In Figure IIC, each of 2~ 75577 ~ WO 95/19258 PCT/US9S/OOS05 the c~"l ~ t~ 31 is ~ b~ -11y Y-shaped, although it may have any selected shape ac well as the i11 _ ~ d shapes.
The elastic c~ 'e s~crificP-c the inherent;, l ilitioC of these '- in the c regions which secure the non-woven fabric to the elastic sheet so that it is rendered 5 ' -11y inelastic in the b_Ul~ ~t regions. Accol.lillgl~, when the provisions of the rows 30 of ~ .~.lt s~ are made to extend _b~ ~'1y t.~;,~.~ly to the readily-~tlc ' ' '^ direction as " ~ in Figures 1 lA, 1 lB, and 1 lC, such provisions greatly reduce the Dhc' ' ' 'lity of the eladic cn~ in the direction parallel to the readily sllct ' -''^ direction even if the -1~
i' 1~ are highly "l.~ ' -''- in such direction, although they rarely affect the ,~ ' -' lity of the 10 ehstic ~ - in the readi1y ,llc ' -''^ direction. S ' -11y, the elastic ~ , -co~llu.,lions as ill t' in Figure 11 e~pand to a very slight extent in the longit~ direction of the rows 30 of s~u.~
For instance, the elastic co~ ~c;l~ shows greatly reduced ~h~tr1 ~t.;1ity in the6~UI~ ' regions even when the non-woven fabric and the elastic sheet are c~.. 1.;. ~ by hydro-15 e ~' to provide such s~ul~ nt regions. In contrast to the elastic c~---y~-:'P as ~r~ d in Japanese Utility Model No. 3-39509,the elastic colll~o~ile of the present invention thus stretches to a very slight degree in the regions where the non-woven fabric and the elastic sheet are tightly hydro ~
However, the elastic c~ e expands freely in the readily,, L-^ direction 20 t ;e.~l~ to the rows 30 of s~ul~,~nt s.,~ until it reaches the elastic limit of the non-woven fabric. The elastic c~- ~ returns to its initial length when the tension is released prior to reaching the limit. On the other hand, as the elastic c~ is further stretched beyond the elastic limit, the non-woven fabric undergoes ~ eJrn" ~.- and never returns to its initial length even after release of the tension, while the elastic sheet sustains its e' 1~ because its ehstic limit 25 is much higher than that of the non-woven fabric and returns to its initial length after release of the tension. When the elastic c . - returns to its initial length upon release, the non-woven fabric becomes pouched between the - g' '- g rows of s_u.c ~o~O
Once the non-woven fabric u~de.y~Ls the p~ . a smaller force is ~ri~- required to stretch the elastic c . - in the readily SIIC' ' ~~^ direction than is 30 required when it is initially stretched beyond the elastic limit of the non-woven fabric. This ' typicallydefines the sllet~,h ~ ~ation as tn~o~ti~n~l above.
As will be 3~ r e ' ' :I from the above description, the elastic ~_--r ~ ~ is re resistant to ~ll~l~& in the direction that the ~urc..,.~.-t regions or the rows of the s_iu c extend than in the readily ~ 'le direction thereof. This means that the rorificPl1y 35 6elected provisions of the s~ul~ t regions or the rows of the s~u.c~.lt ,, permit the elastic cc,.ll~,o~ile to have its ~l.el ' bility generally in a desirable and specified direction even when it co~.iscs the non-woven fabric and the elastic sheet ~ in all li.~tions.

WO 9S/19258 2 1 7 5 5 7 1 -12- PCT/US9S,'~:~SOS

Figure 12A show6 a ' l1y ,. _ ' ela6tic c~ , ~ c . g an elastic sheet and a non-woven fabric which are highly ~h~ ^ in both ~ and y ~ s, respectively. As illustrated in Figure 12B, the elastic c~- q~ includes p~-- ;lJ~ areas B, C of suitable widths respectively _.~. ..l;~,g along its four linear edges to enclose a central area A. Each of the ~
S areas has linear ~ regions 3 which e~tend I i_.~ly to and iu~.~dly from the ~c . ~ ~_ linear ~ i, ' y. The ill d elastic C4 q~O- ' iS ~h~ in any dil_iliu~s in the central area A, only in the ~ L,. in the p~ i~* ' areas B, and only in the y direction in the ~ areas C.
Figure 12C shows an elastic c~--y~ which includes end areas B ., ' g along lû opposite ends of the elastic C~ r and an area D ~ g in the y direction along the y-directional ~ - ' - Those areas have respective linear s~ul~ut regions 3 e- ~ g in the y direction. The elastic c~--y~ further includes end areas E " g along opposite ends thereof.
The end areas E have linear s~...cu._.lt regions 3 which e~tend at an angle of about 45 from the ,e, - ~,_ linear ~ s Acco,.l,..gly, the elastic cc. q~;lr- is highly ,h. ' ' '- in the ~-15 direction in its areas B and D, and is sl,~ ' ~'le in a slanting direction in the end areas E, normal tose c regions 3 in areas E.
Because the elastic cc . - of Figure 12B or C have selected areas ~hc' ' ' lc only in the respectively ~ifi~ directions, it can be ad~ ~u~ly used for an e1astic topshcet or of a ~i~- ''- diaper. In such an event, the end areas B, the end areas C, E and the 20 central area A may serve as waist elastics, leg elastics su~v~udmg leg holes and e~pansive elastics for elastically cc ~ g and ,l,_h,Lug over an area of the diaper. This enables one to scl~li~_ly deaign ~ ''- products which are capable of following any . 5G~
Figure 13 shows still another elastic c~- e 'x ' of the present ._ An elastic c . - 100 is Dh~ ' -''- only in one direction. The elastic ~ , - - is highly 25 .~h.i- '~':1~ initsfirstcecntral area llOand islesssl,G ' '~- oronlyslightly~L. ' 'le initsecond opposite end areas 1 1 1 . The elastic . - with such .~ ~ t-; ~;- c can be obtained by applying further bonding hæ - such as partially heat~- . ~ ve hc to the elastic _ , as prepared in the ~ ~_ - --d manner.
In Figure 14, an elastic c r ~~'- has three slightly stlC- ' ' '- band-like areas 111 30 disposed at regular intervals.
An elastic C4--q~- ~' of Figure lS has highly sh~ '~ areas 110 on opposite sides of a dightly shc ' -''- band-like area 111. In these illu~l, '; ' ' , the elastic c~ , c~ .. ;~ an elastic sheet and a non-woven fabric which are both formed of readily heat-fusible '_1~
E~cam~les of non-woven fabrics suitable for such ,~ui,~.. _.,t includes one cc.. ~ :-.g CU..J~ G t fibers cv -~;- g of a polyester core covered with pol~_lhyl~ e sheath, which is ~. ' -d with a film of S.E.B.S.(s~ ;ùe~thylene-l,_ ' ^ styrene block polymer) as an elastic sheet. This 2 1 7557 ~

terial hâs good propenies of E~ ' 'lity by ultl '- and heat sealing, ~nd can be used in a high speed p.~lu. li.,.. process.
The elastic c . - ' - having a highly-DI.~ area 110 and a slightly sLv~ ' ' '.
area 111 as jl' ' ' in Figures 13 through 15 c n be obtained by applying heat of suitable 5 i , ~ ~i range to the area 111.
Figure 16 is a graph showing the results ~d with regard to a .. ' ' ' '., between tensile strength of an elastic c~ . and tv.ll~ s at which the elastic ~ - ~ - -" is heat-c- . v~l~ The elastic ~ " is prepared by placing an elastic sheet formed of SIS-type film upon . hydro~ non-woven fabric - . ' ' B PET (pol~. ) fibers and i' ~_rt.,. panially 10 heat~ . v ' g them for ' " - The ~ ;cl; s of the elastic c . ' ill ~d in Fig.
16 are obtained by further applying heat and Colllt"G ' to the ..lteg. ~ elastic c . - ' In the graph, Tl indicates the tv.,,~ c at which SIS present in the elastic sheet starts to melt and T2 the ~ . e at which PET present in the - ..~._., fabric stans to melt, d~ As can be seen from Figure 16, heat-co~.~ ~)n below Tl is not ~--rr.. ~ to integrate 15 the elastic sheet and the - ~ J.-n fabric so that the elastic c~ ;t, e~hibits low values of tensile strength while 5~ g good elastic recovery. When the heat~llll,.~Dion is applied to the elastic . - " at a t . ' G r_nging from T1 to T2, at lerst a pan of the elastic sheet melts and is fused to the non-woven fabric so that the elastic cu ~ e~hibits greatly . ' - ~ tensile strength while its showing of elastic recovery d . r~ D. The heat- . ~ ' above T2 causes the elastic 20 sheet and the non-woven fabric to be fusivelybonded to each other so that the elastic - . -"
e~hibits reduced sllet ' -' lity in all dll~
Referring again to Figurec 13 and 15, the elastic cu..~l.v~ c of those ~ "-s also can be obt. ined by utilizing different heat~lc~ - in between the area 110 and the area 111 when ~ the elastic sheet and the non-woven fabric which, re placed upon each other so as to be Dll~ in the sune direction. S~rifi~ ly, the dastic sheet and the - ~.J.-n fabric are panially heat-~ . G~d in the area llOat a t . G ranging between Tl and T2 and are entirely heat c~lv~d in the area 111 at a; . v above Tl to render the aress 110 highly-sh~f ' 'l~ and the area 111 slightlyDI.~' ' ~''^ The d--' ' '- Dll. ' ' 'lity can be given to the elastic c~ ^ in such a manner. Because the Dl.G ' ' lity of the highly-LhG- ' -'If area 110 is controlled or rG~h~v~ by the presence of the slightly-Dl.e~ ~''^ area 111, the elastic c . - ' is r' ' ' lly highly Dll~ -''- in a q~ifi~ direction and is very slightly Dtlet ' ' '^ in the other directions.
Such elastic c . - " having highly ' G' ' ' '^ and slightly-DIl. ' ' '- ueas disposed in mLl~ed and I - ' manner can be applied to various uses. For pl-~ the elastic cr.--~ r.
having the slightly-DI.~ '-''^ ueas 111 disposed on opposite sides of the highly StlG- ' ~''- area 110 such as ill t~ ' in Figure 13 can be applied to tapeless (pant-type) &bs~lbvnt uticles.
Figures 17 ill - an r~5 ~nt article, such as a tapeless diaper, or training pant, having a m~in body 121 C4 ~ g an ~ I, .~t body ' ' ~ o~ between a liquid ~ --~1^

topsheet and a liquid i~ lb'~ The main body is bent along its center line to define a ly U-shaped configuration. An elastic cr~ 100 connects opposite side edges of the U-shaped main body to define a leg hole 122. The elastic c4 ~ k- 100 has the slight1y-~opposite end aress 111~ to the main body 121 and the highly-sl.~i '-''- central area 110 5 rendered free, so that the highly-~h~ h~t~,.islics of the area llOis not ~' ' l,cd. The elastic ~~ . " lOO is cr.~ at its opposite ends to the main body 121 to serve as a side panel of the diaper or training pants.
of the present ill~ n will be now dPsr~heA
E~cample 1 10 Ml ' ' e of an ~ ' 'le non-woven fabric -50 parts of polyester fibers (1/5 denier x 35 mm) is mi~ed with 50 parts of polyesterfibers (2 denier ~ 51 mm). The mi~cture is hlLludu~d into a roller card to prepare a paralle l carded web having a basis weight of 25 g/m 2.
The web has an o.' ~ ' ratio MD/CD of ~. In other words, the strength of the web15 in the machine direction (MD) is seven times its strength in the cross direction (CD). The web is ' . ' e 1 over a porous suction cylinder provided with a d... ~ uiug zone while ~;e ,~ to water-~ ;- . deg~ ' g and d~ ' g. The web then is passed at a running speed of 30 m/min under three banks of water noz~les for water~ ' . ' ' A first nozzle: 0.12 mm diameter ~ 0.4 mm pitch (distance between adjacent water pressure 30 kg/cm2 nozzles in a bank) A second nozzle: 0.12 mrn diameter ~ 0.4 mm pitch water pressure 50 kg/cm 2 A third nozzle: 0.20mm diameter ~ l.Smm pitch water pressure 60 kg/cm2 The e~ web as ~IP~ ;ly~d above is dried and _b ~ is ~ d to heat h. ' so that a web-form non-woven fabric having a basis weight of 30 g/m 2 is ~b ' - ' An S-S curve of this noD-woven fabric when stretched in CD is ' '' d at A in Figure 18.
P~ ~' of an elastic sheet -A blend resin . . ' ' g EMA/EPDM (ethyl methyl a~ ' ' 'eLh~lene p.~, - diene te"~l~l) polyolefin .'- ' ~ is e~ctruded to forrn a film of 25 ~ thick. A S-S curve of this elastic sheet when :.L.. ~-~ in CD is :_d; '~ at B in Figure 18.
O -;~ed cc~
The elastic sheet and the non-woven fabric as prepared ab~ove are placed upon each 35 other prior to h~L~luuLion thereof over a 60-mesh PET net the elastic sheet side facing toward the PET net. A heat roll having F '~ annular grooves thereon is disposed over of the non-woven side and is heated to 130C. A flat or non-grooved roll is disposed bleneath the PET net. The heat roll is pressed against the elastic sheet and fabric so they are cou~,~sd against the flat roll at a line pressure of 10 kg/cm to form an elastic . ~ - .
An S-S curve of the elastic cr--y.o~ thus p.vducod when stretched in CD is jn~
at C in Figure 18.
S A th.~.~_lc test which repeats the 150% stretch and release of the elastic c: -provides results as shown in Figure 1. A - - ~d recovery rate is 75%.
Both-sided co...,~;le -Two sheets of the above elastic Cf~ P' are placed upon each other so that their film sides face toward each other. A - g~w~ed surface heat roll as heated up to 80 C is . ' ycd to 10 apply pressure to the sheets at a line pressure of 20 kg/cm and at a speed of 10 m/min so that a stable bonding c~ n is provided between the facing film sides of the two sheets. The ~ t regions in top and bottom sides are ,~gge.~d from each other so as not to overlap each other. A S-S curve of the resulting elastic c~- qr :~ is ._d;- ~ by D in Figure 18.
A three-cycle test which repeats the 150% stretch and release of this elastic .
15 provides results as shown in Figure 2. A ~f.,.~d recovery rate is 75%.
E~ample 2 C~ P~ C~J~ f~ ' C~ h~5~ a SEBS-type film and a non-woven fabric -A c~ ;on primarily ~ t d by a resin cc , ., a mi~;ture of 75 parts SEBSand 25 parts EVA is e~truded to prepare an elastic film of 25 ~ thick. C~ t~ - lly, this film 20 can be easily bonded onto itself by _ ~ at room t~ -r e.
A slight amount (about 0.4 g/m2) of rubber-type hotmelt adhesive is sprayed onto one surface of the film which then is bonded over its entire surface to a non-woven fabric as similar to the one prepared in E~ample 1 by heat~u~
Both-sided c.... ........~ e -Two sheets of the above elastic r - having the - .. J.~ fabric secured on one side of the SEBS-type film are placed upon each other so that their resp_ctive film sides face toward each other. These two sheets are passed between a pair of non-grwved rolls at a l ~ of about 40 C and under a line pressure of 20 kg/cm 2 to provide a two-sided c _ r " ' which has the non-woven fabrics in its opposite sides and films stably secured to each other.
The olle ~-P~1 and two-sided c~ c thus cou;,llu~t~ show elastic recoveries as similar to those of F~
E~amnle 3 70 parts of polypropylene fibers (2 denier x 30 mm) is mi~ed with 30 parts of polyester fibers (2 denier ~ 57 mm). The mi~ture is i~ltludu~ into a roller card to prepare a parallel carded web having a basis weight of 20 g/m2. The web has a MD/CD ratio of 8Ø
The web is ~t,~L~d over a net conveyor where it is placed upon a melt-blown non-wovenfabric( r ~id byKURARAY Co.,Ltd.)primarily f--~ /tld of SISandhavingabasis weight of 40 glm 2. The c~ -.l.:- d web and non-woven fabric are then introduced over a net provided with nozzles and a d ..~1 g zone where they are ~uL~ ' to multi-stage hydro-e ~ G as shown in the following Table 1.
Table 1 Sta~e Nozzle spec. Pressure Surface .r ~~ of the obtained dastic cc, First stage 0.12mm0 x 0.6mm 30kg/cm2 ---(p.~. ~' stage) Sc-cond stage 0.12mm0 ~0.6mm 50kg/cm2 Figure l9A
(~IV. I stage) Third stage 0.20 mm0 ~ 4.0 mm lOOkg/cm2 Figure l9B
(partial; ' ) Fourth stage 0.15mm0 xO.6mm 80kg/cm2 Figure l9C
(partially ~ t.
The surface ~tlU~.lU-~ of the CO~ '5 obtained at stages are shown in Figures l9A, l9B and l9C. The . ~'-' elastic co ~l~o~;le after the final stage has band-like readily~l.G ' 'lf portions 131 and hardly-sl.æ- '-''- portions 132. A three-cycle test which repeats the 150% stretch and release of only the readily-~l.e" -' 'e portion 131 of the elastic cs_ r~ ' provides results as 20 shown in Figure 20. A ~Al~ recovery rate is 70%. On the other hand, the hardly ,l.~ ' ~''~
portion 132 hardly c~ " elastically and provides a S-S curve as shown in Figure 21. Its breaking point is shown to be 1.2kg/50 mm.
As A~ec~ihed above, the elastic c~ e in ~cco.~' e with the present invention a ~ . fabric which is F c -lly s'~ ~ ''- by higher than 100% in a spccific 25 direction, and an elastically recoverable elastic sheet. The ~ ..J.~ fabric in its I ' ~ state is bonded to at least one surface of the ~ ~ ' - ' elastic sheet through ~ G points to form the elastic, . which has a recovery rate of higher than 60% after G~ g the thre-repeated cycles of 150% stretch and release. Therefore, the elastic cc. ~ of the prcsent invention provides ~ ll pc.r~ -e in elastic recovery and a soft surface touch to a human skin.
30 In pr li.,ular, the elastic cc.--~ of the present invention can be ~ 1~ g~u~ly utilized in . `- ,, an article portion which is brought into direct contact with the hum~ skin, such as a sleeve portion of a medical gown, a waist portion or a crotch portion of a sanitary article.
Although various; ' ~ ' of the invention have been A _ ; kd herein it will be l~ o ' that ~ nnc and m~if- n~^c are possible without d~,,~LA~g from the spirit of the 35 invention as set out in the claims.

Claims

1. A stretch-activated elastic comprising:
a non-woven fabric sheet adapted to be elongated by more than 100% in one direction;
and an elastically recoverable, elastic sheet;
said elastic sheet in its unstretched state being bonded at securement regions to one surface of said non-woven fabric sheet in its unelongated state;
said elastic composite having, per unit width of 5 cm, when stretched in said one direction (1) a stress of lower than 1000 g at 30% stretch, (2) a stress of higher than 400 g at 100%
stretch, (3) a breaking point of higher than 400 g, and (4) an elastic limit of higher than 200%, said elastic composite after being stretched to an elongation of less than 200% having, per unit width of 5 cm, (1) a stress of lower than 500 g at 30% stretch and (2) a stress of higher than 100 g at 100% stretch, and said elastic composite after three repeated cycles of 150% stretching and relaxing having an elastic recovery rate of higher than 60%.

2. The elastic composite of claim 1, which further comprises a second non-woven fabric sheet and wherein the first-mentioned and second non-woven fabric sheets are bonded to opposite surfaces of said elastic sheet.

3. The elastic composite of claim 2, which further comprises a second elastic sheet and wherein the first-mentioned and second elastic sheets each have a first surface and an opposed second surface, said first-mentioned fabric sheet is bonded at securement regions to the first surface of the first-mentioned elastic sheet, said second non-woven sheet is bonded at securement regions to the first surface of the second elastic sheet, and the second surfaces of said elastic sheets are bonded to each other.

4. The elastic composite of claim 3 wherein securement regions between said first fabric sheet and said first-mentioned elastic sheet are offset from the securement regions between said second fabric sheet and said second elastic sheet.

5. The elastic composite of claim 1 wherein the securement region which bonds said elastic sheet and said woven fabric extends in an elongate band in a direction extending transversely of said one direction.

6. The elastic composite of claim 1 wherein said securement regions which bond said elastic sheet and said non-woven fabric are arranged in rows which extend in a direction transversely of said one direction

7. The elastic composite of claim 1 wherein said non-woven fabric comprises a fabric produced by water-entanglement and having a two-phase expansibility at different stress levels.

8. The elastic composite of claim 7, wherein said non-woven fabric comprises a fabric whose elongation at a second phase takes place at an elongation rate of higher than 150%.

9. The elastic composite of claim 1 wherein said elastic sheet comprises heat-fusible material.

10. The elastic composite of claim 9, wherein said elastic sheet and said non-woven fabric are, in a specified area of the elastic composite, bonded to each other by heat compression above the temperature at which the elastic sheet starts to melt but below the temperature at which the non-woven fabric starts to melt to form a slightly-stretchable portion which is more resistant to stretching than the remaining portions so that the elastic composite has a specified stretchable direction.

11. The elastic composite of claim 10, wherein said slightly-stretchable portion is provided in a band-like manner.

12. The elastic composite of claim 9, wherein said non-woven fabric consists of fibers which are easily fusible by heat.

13. An elastic composite comprising an elastic sheet and a non-woven fabric, said elastic composite including a highly-stretchable area which is constructed by partially bonding said elastic sheet to said non-woven fabric and a slightly-stretchable area which is constructed by substantially entirely bonding said elastic sheet to said non-woven fabric.

14. The elastic composite of claim 13 wherein said slightly-stretchable area comprises a plurality of band-like securement regions between said fabric and elastic sheet extending parallel to each other.

15. The elastic composite of claim 13, wherein said elastic composite includes said slightly-stretchable portions adjacent its opposite ends.

16. A stretch-activated elastic composite comprising:
a non-woven fabric having a potential elongatability of higher than 100% in one direction; and an elastically recoverable, elastic sheet;
said elastic sheet in its unstretched state being bonded to at least one surface of said non-woven fabric in its, unelongated state at securement points, said elastic composite having, per unit width of 5 cm, (1) a stress of lower than 800 g at 30% stretch, (2) a stress of higher than 600 g at 100% stretch, (3) a breaking point of higher than 400 g, and (4) an elastic limit of higher than 200%, said elastic composite after being stretched at a rate of lower than 200% having, per unit width of 5 cm, (1) a stress of lower than 300 g at 30% stretch and (2) a stress of higher than 200 g at 100% stretch, and said elastic composite after three repeated cycles of 150% stretching and relaxing having an elastic recovery rate of higher than 60%.

17. A disposable absorbent garment comprising:

an absorbent body portion having a substantially U-shaped configuration to conform to the crotch region of a wearer with opposed front and rear end portions adapted to be disposed adjacent the front and back of the wearer and having opposed side edges, and a side panel interconnecting adjacent side edges of the front and rear end portions, said side panel being an elastic composite including an elastic sheet and a non-woven fabric, said composite including a highly-stretchable area which is constructed by partially bonding said elastic sheet to said non-woven fabric and a slightly-stretchable area which is constructed by substantially entirely bonding said elastic sheet to said non-woven fabric, said slightly stretchable area being much less stretchable than said highly-stretchable area.

18. The garment of claim 17,wherein said slightly-stretchable area comprises a plurality of band-like securement regions between said fabric and elastic sheet extending parallel to each other.

19. A stretch-activated elastic composite comprising;
a non-woven fabric sheet adapted to be elongated by more than 100% in one direction;
and an elastic sheet having an elastic recovery rate of higher than 60% and an elastic limit of higher than 200%;
said elastic sheet in its unstretched state being bonded at securement regions to one surface of said non-woven fabric sheet in its unelongated state;
said elastic composite having, per unit width of 5 cm, when stretched in said one direction (1) a stress of lower than 1000 g at 30% stretch, (2) a stress of higher than 400 g at 100%
stretch, (3) a breaking point of higher than 400 g, and (4) an elastic limit of higher than 200%, said elastic composite after being stretched to an elongation of less than 200% having, per unit width of 5 cm, (1) a stress of lower than 500 g at 30% stretch and (2) a stress of higher than 100 g at 100% stretch, and said elastic composite after three repeated cycles of 150% stretching and relaxing having an elastic recovery rate of higher than 60%.