GB2260708A

GB2260708A - Sanitary napkins

Info

Publication number: GB2260708A
Application number: GB9222141A
Authority: GB
Inventors: Yumiko Aramaki; Akiko Itoh; Takatoshi Kobayashi; Hisanobu Tanaka; Susumu Tohhei; Hiromi Baba
Original assignee: Kao Corp
Current assignee: Kao Corp
Priority date: 1988-11-28
Filing date: 1989-11-28
Publication date: 1993-04-28
Anticipated expiration: 2009-11-28
Also published as: GB8926841D0; HK60294A; MY104483A; GB2227174B; GB2260708B; HK88694A; GB2227174A; GB9222141D0

Description

SANITARY METHOD 1 2,211) 3 "') ".

"hi s invention relates to a method of absorbing menstrual flow utilising anabsorbent article having high antileakage properties. More particularly it relates to a method of using an absorbent article such as a sanitary towel or napkin where the leakage along the depression between the buttocks of a user can be remarkably lowered.

Conventional absorbent articles, for example. sanitary napkins and disposable nappies or diapers basically comprise an absorber such as a cotton pulp or an absorbent paper sheet, an antileakage material provided at -he bottom and sides of said absorber and a surface material placed thereon.

Recently, an absorbent article wherein a lengthwise side of an absorber is cut so as to form a dent to thereby allow the absorbent article to closely adhere to the crotch and thus prevent the leakage of a body fluid has been proposed. Further a process for inhibiting the leakage of a body fluid from the crotch has been proposed.

results.

These techniques produce certain However, it is impossible by these methods to prevent the leakage of a body fluid along the depression between the buttocks which is frequently observed during sleep.

1 1 r Thus there have been proposed various techniques to f orm. a raised portion at the rear centre of an absorbent article to -,-mprove the adhesion of the absorbent article to the buttock depression thus solving the above-mentioned problem.

For example, one such technique comprises curving the rear part of an absorber so as to f orm a raised portion. However, this method essentially requires a highly complicated production process. In addition, it is unavoidable that the raised portion comprising a highly rigid material such as pulp or Daper would give a serious feeling of physical discomfort to a user.

on the other hand, another proposed technique comprises placing a flexible material at the rear centre of an absorber so as to form a raised portion. In this method, a highly flexible raised portion would cause no feeling of physical discomfort. Once a compression stress caused by the body weight or motion of a user is applied to the raised portion, however, the raised portion is broken and shows no recovery even when the compression stress is removed. Therefore this product has a poor adhesiveness. The substantial disappearance of the raised portion as described above is particularly obvious when a body fluid is excreted and the raised portion is in a moist state.

As a result, the desired inhibition of the leakage along the buttock depression can be hardly achieved.

z 9 t J - Thus there has been no process which makes it possibe effec---ively to inhibit the leakage of a body fluid along the buttock depression by improving the adhesion of an absorbent article to the buttocks without reducing comfort. Thus it has been impossible to overcome hygienic and psychological discomfort of users and helpers, in 1Darticular,dur-;ng sleeping, which causes a serious problem.

Under these circumstances, the present inventors have conducted extensive studies in order to develop an absorbent article where the leakage of body fluid along the buttock depression can be effectively inhibited by improving the adhesion thereof to the buttocks without a reduction in comfort, thus completing the present invention.

provide a According to this invention we method of absorbing menstrual fluid by means of a sanitary article comprising a liquidretaining absorbent material between a liquidpermeable top sheet material and a liquid- impermeable anti-leakage bottom sheet material, the article being substantially of rectangular form and provided with a pair of flexible flaps one of which extends laterally from each side, wherein the flaps are spaced from the centre of the articles towards the part of the article which, in use, is the front part, wherein the sanitary article is fitted with the top"sheet material facing the wearer and with the end of the article towards which the flaps are displaced at the front.

4 It is preferred that the dry compression recovery extent of the central part of the rear part is 25 percent or above. It is preferred that the f laps are hydrophilic on the front surface to contact the skin of a user and then hydrophobic on the rear Sur= face to be connected with a It is preferred that th e tape fastener.

hydrophilic surface of the f laps has a water-absorbing rate of 200 seconds or less and the hydrophobic sur-face of the flaps has a waterabsorbing rate of 500 seconds or more.

The -invention provides another embodiment of the method, wherein the sanitary article is provided at a central part in the widthw,-se direction of the rear part of the article between the surface material and L-he absorbent with an elastic me=ber, said central part having a modulus of co=pression rigidity of 15 to 38 percent, said central part having a dry compression recovery extent of 2-5 percent or more.

The invention provides a third embodiment of the method wherein the sanitary article has a structure such that folded portions of the flaps are located below the absorbent when the art ic le is us ed by a wear er.

S Examples of the invention will now be described with reference to the accompanying drawings. Figs. 6,7, and 8 show sanitary napkins the use of which is outside the scope of this invention.

Fig. 1 is a plan view of an example of the absorbent article for use in the present invention, Fig. 2 is a sectional view of the article of Fig. 1 along line C - C', Figs. 3 and 4 are sectional views corresponding to Fig. 2 of other examples of the absorbent article for use in the present invention, Fig. 5 shows a process for fixing the absorbent article to the clothing, Fig. 6 a -clan view of a conventional absorbent article, rig. 7 is a sectional view of the article of rig along line.A - A', and Fig. 8 shows a process 'or.f4xJng the same to the clothing.

Figs. 11 to 14 each show a schematic plan view of an example of the absorbent article for use in the present invention. However, the flaps are not shown in these figures. Fig. 15 shows load/displacement curves to be used in the determination of physical properties including modulus of compression rigidity.Fig. 16 j S 6 shows a sanitary napkin simulation sample used in the Examples of the present invention, wherein (a) is a plan view, (b) is a sectional view of (a) along i-ine A - A' and (c) is a sectional view thereof along line B - B'. _Pig.17 is a schematic sectional view of a device for the determination of physical properties such as modulus of compression rigidity. Fi g. 18 Ls a DersiDective view of a f emale hip model to be used in the determination of absorption in supine nos it- ion.

7 The absorbent article according to the invention has flexible flaps or lugs which extend from both lateral sides of a position displaced lengthwise towards the front.

1 8 Dif-ferent from a conventional absorbent ar-icle shown in Fig. 6, the absorbent article for use in the present Jnvention involves flexible lugs 2 extended from the lateral sides at a position displaced lengthwise towards the front. - the rear part of the absorbent Thus the length of L L material starting from the lug, which roughly the excretion of a body of the front part thereof.

of Fig. 6, namely, the absorbent article 1 is the lateral center line contrast thereto, the corresponds to the point of 4rluid, is longer than that In the conventional article lateral center line of the substantially in line with A - A' of the lugs 2. In 9 lateral center line B - B' of the absorbent article 1 -of the present invention of Fig. 1 is not substantially in line with the lateral center line C - C' of the -lugs 2. Accordingly the area of the part covering the buttocks is relatively larger than that of the part covering -IC-he pubic part. As a result, the leakage from the buttocks can be remarkably suppressed in the a 46- ter case, even when the length of -he absorber is the same or somewhat smaller than that of a conven-tional absorbent article. In the present invention, it is preferable that the lateral center line B - B' of the absorbent article is apart f-rom the lateral center line C - C I of the lugs at least by 10 mm.

Furthe=ore, Fig. 3 shows a preferable example of the embodiment of the absorbent article for use in the present invention. In this embodiment, one surf ace of the absorber 6 to be against the skin of a user and the other surface to be against the clothing o- 1 the user are covered respectively with surface:ace material 4 on the materials 4 and 5 The si-,=-L surface to be against the skin of the user is iiauid-ne--meable, Vli-Jle the surface, material 5 on 1 face to be against the clothing of the user he SUrL Js substantially liq,.iid-ir,.perrneable. In this article, the lugs 2 and the liquid-impermeable part 5 would both act to contain the excreted liquid, thus achieving excellent antileakage properties.

Anv surface in-=-:-erial such as z)a-Der, nonwoven - az _- I -_ I - - I m, n e t a n d I ana -4-nalte thereof may be used 4- :Ln the present -inverzion. Among these materials, with nonwoven fabrics are particul"Larly -creferable from -the viewpoint of sticckLness of the surface. When a film. or a net M s shown in Pig. 2, o-o%--- --he sur-Eaces o be against n de pores on both of t -o 1-o the skin and th.e clotning of a user so as t achieve liqui-d- perrineabi-lity. However it -Js highly desirable, as show-n -in rig. 3, to make the sur-face t %_o he against the clothing of the user substantially licTuid- impermeable by forming no poreSthereon so as to improve the antileakage properties.

For use in the present invention, any lug 2 may be used so long as -it Ls suffic-Jently flexi-hle to be easily 11 bent so as to be fixed to the clothing 7 as shown in Fig. 5. However it is preferable to use a liquid -impermeable jug from the vies%-po-4n'L of anti-leakage properties. As Fig. 4 shows, the lug 2 may also be constituted of an assembly of an antileakage material 3, a surface material 4 and an absorber 6. However it is preferable to extend the antileakage material 3 from both la-Lerial sides of the absorbent article to thereby form the lugs, since a simple structure can be achieved in this case.

T 'he size of the lug 2 -is not restricted but may vary depending on the size of the absorbent articcle- in -the case of an overnight sanitary napkin 250 mm in length and 70 mm in width, the lenath and width of the lug ferably range respectively from 30 0 70 mm may pre.

L_ and from 25 to 50 mm, taking stability and the ease in fixing the napkin to the clothing into consideration. The lug may preferably be displaced by 20 to 40 mm from the lateral - art center line of the absorben4L %-:Lc le Examples of the absorber to be used in the present invention include known ones such as aggregates of pulp, rayon or synthetic fibers, polymer absorbers and -foamed materials. It Ls prefEerable to use a 12 mixture of a hydrophilic fiber such as rayon with a synthetic fiber such as polyester f or the surface to be opposed to the skin of a user so as to reduce stickiness.

Any antileakage material may be used in the present invention so long as it is liquid-impermeable. IIxamnles 'hereof include films, nonwoven fabrics, water-remellent T)aDers and laminates Ithereof. Among L-hese materials, a laminate of a film and a nonwoven fabric is preferable from the viewpoint of t J I-exture. It is still preferable, as shown in Fig. 3, that a laminate of a film and a nonwoven fabric is used in such a manner that the nonwoven fabric is opposed to the body of a user.

in order to more firmly fix the absorbent material to the clothing, it is preferable to add a A- tackii.fier or a non-slip agent to the lugs or the absorbent material per se.

The absorbent article for use in the present invention is not restricted by the examples described -in detail 1 13 a.bove but various modification may be done within the abDve-mentioned scoDe.

The absorbent article for use in the present invention shows a considerable decrease in leakage from the buttocks when compared with conventional ones. In particular, the article of Example 2 which involves a liguidimpermeable part in the surface material opposed to the clothing shows a remarkable decrease in leakage from the crotch, which suggests that it is an ideal absorbent article.

Flaps having one hy-drophilic surface and the other hydrophobic surface The article for use in the invention preferably has.flexible flaps having one hydrophilic surface and one hydrophobic surface, giving improved absorption of a high viscosity liquid.

The flaps may be produced from non-woven fabric, film or a foamed material.

It is preferred that the front surface to contact the skin of a wearer of the article is made of a porous non-woven fabric. The front surface may alternatively be made of a 1 14 heat-f u s ed non-wov en f abr ic of synthe t ic re s in f ibers, such as polyester f ibers or conjugated f ibers of polyester and another material. The gauge of the fibers is preferably 2 or more denier, especially from 3 to 6 denier. The front surface may be further treated with a surfactant. Melt adhesion of the fibers is ensured by blowing with hot air. After the blowing, it is better to heat the surface.

It is preferred that the rear surface to contact the clothes of the wearer is made of a non-porous synthetic resin film, such as a sheet of polyethylene having a density of 30 erent resin layer to 50 g/=2 and a la=inate of some dii s.

The front surface layer and the rear one aremelt bonded to each other. Bwetween them, an absorbent paper may be inserted.

elastic rnaterial Preferably, a sanitary article for use in the invention having flaps which are hydrophilic on the top surface and hydrophobic on the bottom surface is provided at least on a central part (in the lateral direction) of the rear part of the article between the surface material and the absorbent with an elastic member, said central part having a modulus of compression rigidity, as herein defined, of 15 to 38 per cent, said central part having a dry compression recovery extent, as herein defined, of 25 per cent or more.

We have found out that the problem of satisfying the mutuallyinconsistent requirements of improving the adhesion of an absorbent article to the buttocks and preventing the discomfort in use can be satisfied by providing an elastic material having a high flexibility and a high compression recovery between a surface material and an absorber at least at a central part in the widithwise direction of the rear part of the abso--bent article As described above, the elastic material should have a certain flexibility in order to avoid the discomfort during use. This flexibility is expressed numerically as the modulus of compression rigidity which will be described in detail in the Examples. The modulus of compression rigidity may be calculated by multiplying the ratio of the compression work done practically measured in a cornoression test at the rear center of the.absorbent article under given conait-ions 16 (corresponding to the area of the f igure ADBC in Fig.15) to the compression work done when the absorbent article is assumed to be completely elastic (corresponding to the area of the triangle ABC in Fig. 15) by 100. A lower modulus of compression rigidi-ty indicates that the elastic material is more flexible. In order to impart an appropriate -; rlexib:Llity to the absorbent article, the modulus of compression rigidity should be 38% or below, preferably 32% or below. When the adhesion is taken c.onsiaeration, the modulus of compression rigidity should he 15% or above, preferably 20% or above.

When it is lower than 15%, the rise is too flexible and thus it is difficult to maintain the shape of the -i Sc Tn tl,-Js case, therefore, the poor adhesion is a disadvantage.

Thus it is preferred in the present -L.nvention that the modulus of compression rigidity ranges- ':rom 15 to 39%, preferably from 20 to 32%.

On the other hand, the elastic material should show a high compression recovery, at least in the dry state, in order to prevent the substantial disappearance of the rise as described above. This compression recovery can be expre.ssed numerically as a dry compression recovery rate which will be described in 17 detail in the Examples hereinaf ter. The dry compression recovery rate can be calculated by multiplying the ratio of the compression recovery work done practically measured in a compression recovery test under given conditions (corresponding to the area of the figure AEBC in Fig.] 5) to the compression work done (corresponding to the f igure ADBC in Fig. 15) by 100. A higher dry compression recovery rate indicates that the elastic material shows higher compression recovery. In order to inDart an amDromriate commression recovery to the absorbent article, the dry comiDression recovery rate should be 25% or above, preferably 28% or above.

When a fluid is exhausted and the rise is moist, the leakage of the fluid along the buttocks depression can be more effectively inhibited by providing an excellent adhesion of. the absorbent article to the elast depression. Thus it Is preferable that k-ic materi.al also has a high wet compressLon recovery rate. The compression recovery in a wet state can be expressed numerically as a wet compression recovery rate which will be described in detail in the Examples hereinafter. In order to Impart an appropriate compressi-on recovery---to the elastic material, the wet commression recovery rate should be 25% or above., 1 is preferably 28% or above.

For the present invention, it is preferred that an elastic material having a flexibility and a compression recovery, each as described above, is mrovided between a surface material and an absorber at least at a central Dart in the widthwise direction of the rear part.

Pigs. (1 to 14 show each an embodiment of the a,-,so.-bent article for use in the present invention.

As Fig. 11 shows, the absorbent article should preferably comprise an elastic material 12 having a flexibility and a co=ression recovery, each as described above, at a central Dart in the widthwise direction of the rear Dart of -,-he abso--ben'k. articlell. As Figs. 12 to14 show, it is also possible tc, mrovicle said elastic material12 at other nart(s) n addition to the rear central Dart. However -Lt is undesirable to provide ithe elastic material 12 at both sides in the widthwise direction of the front Dart, since the adhesion of the absorbent article to the buttocks depression might be lowered in this case. Furthermore, it is preferable that no elastic Eront Dart of the materia112 is present in the i A absorbent articlell in order to achieve clos"e adhesion, as,shown in Fias.11 and12. Namely, it is preferable 19 that the elastic material 12 be provided exclusively at the central part in the widthwise direction of the rear part of the absorbent material, as shown in Fig. 11. However, an absorbent article showing considerably high antileakage properties and good comfort in use can be obtained even when the elastic material 12 is provided in the manner as shown in Fig. 1-2 or 13, so long as both of the flexibility and compression recovery of said elastic materi-al fall within the desirable range. That is to say, the uosition of the elastic material can be widely varied by taking the flexibility and compression recovery thereof into consideration.

In the present invention, the size of the elastic material is not particularly specif ied, since it may vary depending on the' size of the absorbent' article and the properties of. the elastic material. In an absorbent article of approximately 250 mm in length and 75 mm in width to use over nightr however, a lengthr width and thickness of the elastic material preferably range respectively from 20 to 250 mm, from 10 to 60 mm and from 5 to 50 nun, still preferably from 50 to mm, from 20 to 4Q. mm and from 20 to 40 mm. Any elastic material 1 r) C, X_ may be used so long as it has a modulus of compression rigidity of 15 to 38% and a dry compression recovery rate of 25% or above. Thus, neither its shape nor its composition _Js particularly restriczed. It may be or f made of, for example, f Loamed material.

From the viewpoints of productivity and cost, aggregates may be preferably employed. Among these materials, a so-called web where short fibers slightly int-erlock together is particularly preferable. Fibers constituting said web may p-referably have a fineness of 2 to 8 denier (d), s-a-41111 preferably 3 to 6 d, and a flibeer lenath of 5 --o 7 mm, preferably to 20 mm. The sectional view of the fiber is pref'--rably hollow or od6-shaped, by taking the comnression recoverv Lntc conside--az.-ion.

The elastic ina,-erial may comprise, for example, hydrophilic ma-!_-erial such as a cellulose polymer, hydrophobic mazerLal such as a Do1voielin polymer or a polyester polymer or a mi_x4,_--_ure oil a hydorphilic ruater-Lal with a hydrophobic material. It may ter fibers from the viewpoint preferably comprise polvest -1c of compression recovery. Furthermore, the elast "erably have appropriate hydrophilic material may pret properties from the viewpoint.- of absorp-tivity. Namely, it Ls preferable that the elastic material 1 1k 21 be a mixture of a hydrophilic material with a hydrophobic material. A web comprising polyester fibers and rayon fibers at a ratio by weight ranging from 40/60 to 80/20 is particularly preferable. When the surface of the hydrophobic material is hydrophilically treated in this case, the hydrophilic properties of the whole elastic material can be more delicately controlled, Thus it is highly desirable to use such.a material.

The surface material, absorber and anti-leakage material of the absorbent article for use in the present invention are not particularly critical and any materials used in the preparation of known conventional absorbent. articles may be used folded portions of the flaps The sanitary article for use in the invention may have a structure such that folded portions of the flaps are located below the absorbent when the article is being worn. This will prevent the sanitary article from slipping out of the correct position.

1 r) r, X, z The article displays excellent comfort in use and is superior in antileakage properties when the wearer is in the supine position.

In particular, the samples of Examples 2 to 5, e-ach having an elastic material exclusively at the central part in the widthwise direction of the rear part and showing a wet compression recovery rate higher than 25%, showed excellent antileakage 6- properties.

On the other hand, the sample of Comparative Example 1 having no elastic material showed poor antileakage properties. The sample of Comparative Example 2 having an elastic material of a modulus of compression rigidity exceeding 38% was inferior not only comfort during use but also in antileakage properties because of the low dry and wet compression recovery rates. Further, the sample of Comparative Example 3 showing a modulus of compression rigidity lower than 15% showed poor antileakage properties.

Thus it is concluded that the comparative samples are unsatisfactory as absorbent materials.

E-Examplel

To further illustrate the usefulness of ithe present invention, and not by way of limitation, the 23 following Examples will be given. Examples 1 to 3 and Comparative E. 'xample 1 Sanitary napkins for use in the present invention comprising the following surface material, absorber and ant-Jleakage material shown in Figs. 2, 3 and 4 and a conventional one shown in Fig. 7 were prepared. Each lug was 50 mm in length and 35 = in width.

In the case of the sanitary napkins for use in the present invention, the line B - B' was 30 mm a-Dart from the lineC -C' (cf. Fig. l)- surface materi-al: A polyet-hylene film was laminated on a heat-bonded nonwoven fabric mainly comT)r:Ls:Lng polyolefi-n and the obtained integral material was embossed so as to form pores. ThLs surface material was provided in such a manner that -cilm was uresent on the surface to be opposed the -to the skin.

A--so--be---- An absorbent paper, a cotton pulp and a polymer absorber were successively laminated so as to give a sheet of 250 mm in length and 70 mm in width.

Antileakage materialt A Dolyethylene film was laminated onto a heatbonded nonwoven fabric comprising a polyester fiber. The integral material thus obtained was provided in such a manner that the film 2 4 41 was opposed to the clothing.

The amounts of a test liquid absorbed by each sanitary napkin thus obtained until leakage was observed from the crotch (in orthositatic position) or from the nates (in supine position) were measured by using a manikin.

Table 1 shows the results. A larger value indicates the higher an-LIleakag;. properities at the crotch or buttocks.

Table 1

Structure Absorption (g) Absc---otion (g) sectional (orthostatic) (suDine) plan view view Fig. I Fig. 2 5.95 7.61 Ex. 2 do. Fig. 3 9.88 11.45 Ex. 3 do Fig. 4 5.38 6.34 Comp. Ex. I Fig. 6 FJ-g. 7 5.36 3.28 Examples 4 to 18 and Comparative Examples 2 to 4 From a commercially available sanitary napkin (Laurier overnight of Kao Corporation) "Laurier" is a Registered Trade Mark, having c ... 1 an absorber of 250 mm in length and 75 mm in width, a surface material and an antileakabe material were removed. Then an elastic materialf2 of the composition shown in Table 'I was laminated on the given position of an absorber14 shown in Fig.16 in such a manner that the lower end of the elastic material was always in line with the lower end of the absorber14 while the elastic material was arranged so as to be always symmetric in the widthwise direction. Further, a surface material/3 comprising a heat- bonaed polyester nonwoven fabric and an antileakage material 15 comprLsing a laminate of wet polyester nonwoven fabric and an' ionomer resin film were provided to thereby give a sanitary napkin simulation samplell'. In Fig. 11, (a) is a plan view of the sanitary napkin simulation sampleil', (b) is a sectional view of (a) along A - A'-, while (c) is the sectional view thereof along line B - B'.

The physical properties and perormance of the sanitary napkin simulation sample thus obtained were determined by the following methods. Table 1 shows the results. (1) Modulus of compression rigidity, dry compression recovery rate and wet compression recovery rate Procedure 2.6 A Tensilon type RTI1-25 (mfd. by Toyo Baldwin Co.) was employed. First, a pr6ssure-sensing plateP of 30 mm in diameter was attached to the tip of a compression lead cell/6 shown in Fig.17, which will be referred to merely as the cell hereinafter. This cell was slowly lowered and gently contacted with a samDle stand in such a manner that the distance between the pres sure -sensing plate and the sample stand was assumed to be zero when a load of 5 kg was recorded.

-he cell/6 was raised by 20 mm and the Next, -IL simulation samplell' was placed on the sample stand/8 in such a manner that L-he surface of the sample to be onnosed to -%'-he skin was directed uiDward. Then the cell/6 was lowered. When a load of 5 kg was recorded, sed up to the starting position. The L-he cell was rai thus obt load/displacement curve -;L L-ained was recorded.

The dete=ination was conducted under the following conditions:

rate of cell lowering and rise: 10 mm/mIn scale of recording sheet: 10 kg scanning rate of recording sheet: 100 mm/min. Calculation -ig.15 shows the load/aisplacement curve recorded on the sheet. Curves ADE and AEB are loaa/aisplacement c r 1 1 27 curves recorded.respectively during lowering and rise of the cell. The former is generally located above the latter. The area of the triangle ABC and that of the figure AEBC in this sheet were measured and the modulus of compression rigidity and the dry compression recovery rate were calculated according to the following equations:

modulus of comDression rigidity ADBC/ABC x 100 dry compression recovery rate (%) AEBC/ADBC x 100 (2) Wet compression recovery rate -he cc of deionized water was Pipetted onto 4.

-he rear central Dart in the widthwise direction of t 1 Dart of thesanitary napkin simulation sample and rapidly absorbed thereby. Immediately after the absorption, the same test as the one described in the above item (1) was conducted and the wet comDression recovery rate was calculated according to the --Following eauation:

wet compression recovery rate A13C/ADBC x 100.

(3) Absorption period The time required for the absorption of a given amount of a test liquid by the central part in the widthwise direction of the rear part of ithe sanitary napkin simulation sample was de-Eined as the absorption period.

1 IQ - - O, D (4) Absorption in supine position A female hip model/9 in the supine position was provided with the sanitary napkin simulation model/11 in the manner as shown in FigJB. A test liquid was fed to the model/l' via a tube 10 and absorbed by the sample /11. The amount of the test liquid absorbed until the leakage became discernible was defined as the absorption in supine position.

(5) Feeling of physical discomfort.

Healthy female adults were allowed to wear the sanitary napkin simulation samples and the feeling of physical disorder thereof was organoleptically evaluated according to the following criteria 1: feeling of considerable physical discomfort 2: feeling of somewhat physical discomfort 3: feeling of little physical discomfort 1 4 5 6 7 8 9 17, 12 14 is 16 17 18 Composition (ratio) Ray (1001) Ray/PET (701/30t) Ray/PET (501/501) Ray/PET (30%/70%) PET (100%) Ray/PET (301/701) #I Ray (1001) Comp. Ex. 2 4 5 Table 1.

none kraft pulp (100%) pp (1001) Elastic material Physical properties Performance Basis Modulus of Dry compression wet compression Absorption Absorption weight Length Width compression recovery rate recovery rate period In supine (g/m2) (mm) (mm) rigidity (1) (1) (sec.) position (11) (9) 80 30 37.6 29.5 24.5 7 29 32.6 30.4 2 6.5 0 41 31.1 31.0 27.6 10 so 29.2 31.9 29.7 13 72 11 1. 26.4 36.1 32.4 18 55 33.0 30.5 26.7 a 50 25.0 33.4 31.9 is 62 40 30.0 31.7 29.8 12 60 29.4 32.1 30.0 13 59 250 30.5 31.0 30.5 14 54 is 29.1 32.0 30.4 12 56 1 75 28.0 32.3 29.8 is 57 250 It 29.0 31.9 30.2 17 27 250 30 37.9 30.0 23.4 7 25 so 75 37.6 29.7 23.0 0 27 - 44.7 24.0 17.3 5 12 80 30 40.9 23.2 16.7 6 20 13.6 26A '24.5 22 23 Feeling of physical disorder Note) Ray: rayon fiber (4 d x 15 mm). PP: polypropylene fiber (1.5 d x 15 mm). PET- polyester fiber (4 d x 15 mm).

t\D CD

Claims

1. A method of absorbing menstrual fluid by means of a sanitary article comprising a liquidretaining absorbent material between a liquidpermeable top sheet material and a liquid-impermeable anti-leakage bottom sheet material, the article being substantially of rectangular form and provided with a pair of flexible flaps one of which extends laterally from each side, wherein the flaps are spaced from the centre of the articles towards the part of the article which, in use, is the front part, wherein the sanitary article is fitted with the top sheet material facing the wearer and with the end of the article towards which the flaps are displaced at the front.

2. A method according to claim 1, in which the dry compression recovery extent, as herein defined, of the central part (in the lateral direction) of the rear part is 25 percent or above.

3. A method according to any preceding claim in which the flaps are hydrophilic on the top surface to contact the skin of a user and hydrophobic on the bottom surface.

t

4. A method according to claim 5, in which the hydrophilic surface of the flaps has a waterabsorbing rate of 200 seconds or less and the hydrophobic surface of the flaps has a waterabsorbing rate of 500 seconds or more.

5. A method according to any preceding claim which is provided at least on a central Part (in the lateral direction) of the rear part of the article between the surface material and the absorbent with an elastic member, said central part having a modulus of compression rigidity, as herein defined, of 15 to 38 percent, said central part having a dry compression recovery extent, as herein defined, of 25 percent or more.

6. A method according to claim 5, in which th elastic material is provided exclusively at the central part of the rear part.

7. The method according to any preceding claim which has a structure such that folded portions of the flaps gets located below the absorbent when the article is used by a wearer.

P. A method according to any preceding claim of absorbing menstrual fluid overnight wherein the - 3L article has a length of 25Gmm, a width of 70mm, and in which the length and width of each flap is respectively from 30 to 70mm and from 25 to 50mm.

9. A method according to claim 8, wherein the flap is displaced by 20 to 40mm towards the front of the article from the lateral centre line of the article.

10. A method according to claim 9, when appendant to claim 5, wherein the length, width and thickness of the elastic material are respectively from 20 to 25Omm, from 10 to 60mm, and from 5 to 50mm.

10. A method according to claim 9, when appendant to claim 5, wherein the length, width and thickness of the elastic material are respectively from 20 to 25mm, from 10 to 60mm, and from 5 to 50mm.

11. A method according to claim 10, wherein said length, width and thickness are respectively from 50 to 150mm, from 20 to 40mm and from 20 to 40mm.

12. A method according to claim 1 wherein the length and width of each flap is from 30 to 70mm and 25 to 50mm respectively.

13. A method according to claim 9 wherein the lateral centre line of the flaps is displaced by 20 to 40mm towards the front of the article from the lateral centre line of the article.

1 - 3) - 14. A method according to claim 1 wherein the permeable top sheet material is provided with pores.

15. A method substantially as described herein with reference to the accompanying drawings, other then Figures 6, 7 and 8.

Amendments to the claims have been filed as follows A method of absorbing menstrual fluid by means of a sanitary article comprising a liquidretaining absorbent material between a liquidpermeable top sheet material and a liquidimpermeable anti-leakage bottom sheet material, the article being substantially of rectangular form and provided with a pair of flexible flaps one of which extends laterally from each side, wherein the lateral centre line of t]:e flaps is spaced from the centre of the article towards the part of the article which, in use, is the front part, wherein the sanitary article is fitted with the top sheet. material facing the wearer and with the end of the article towards which the flaps are displaced at the front.

9. A method according to claim 8, wherein the lateral centre line of the flaps is displaced by 20 to 40mm towards the front of the article from the lateral centre line of the article.