CA1176402A

CA1176402A - Sanitary napkin with improved comfort

Info

Publication number: CA1176402A
Application number: CA000419666A
Authority: CA
Inventors: Billie J. Matthews; Paul S. Woon; Stephan R. Bornslaeger; Robert A. Stevens; John P. Allison
Original assignee: Kimberly Clark Corp
Current assignee: Kimberly Clark Worldwide Inc
Priority date: 1982-02-04
Filing date: 1983-01-18
Publication date: 1984-10-23
Also published as: IT1164603B; BR8300537A; ZA83422B; FR2520609B1; GR77413B; FI830212A0; AU1062783A; FR2520609A1; GB8302379D0; US4397644A; NO830352L; GB2114445B; IT8347629A0; FI830212L; SE8300574L; KR840003409A; TR21752A; AR231918A1; GB2114445A; NL8300264A

Abstract

ABSTRACT
A sanitary napkin is provided which i 8 capable of transmitting viscous menstrual fluid into the absorbent portion of the napkin without cover runoff. The napkin has a fluid permeable cover which is integrated with a portion of the absorbent matrix. This portion of the absorbent matrix is also designed to provide increased comfort, initially during use, and after the napkin has become wet.

Description

1~6~

FIELD OF THE INVENTION
This invention relates generally to sanitary napkins and particularly to a sanitary napkin fea~uring improved comfort and absorbency.
BACKGROUND OF T~E INVENTION
Sanitary nap~ins are conventionally mad~ o~
layers of cellulosic materlal such as wood pulp fluff, creped wadding or the liXe. These materials provide relatively good absorbency and some shape recovery when dry. Unfortunately, when these napkins are wet, the cellulosic ma~erial collapses, loses its shape and is much less comfortable to the wearer; with tha result that even the low Levels o~ shape recovery and ~lexibility present in the c~llulosic material in the dry ~tate tand to disappear.
Recognition of the discomfort problems associated ~ith these napkins, both in the wet and dry form, has produced a variety of solutions. One of these solutions involves the addition of so-called super-absorbent materials to a sanitary napkin with theconcomitant decrease in conventional cellulosic absorbents. This has resulted in a thin napkin which distorts easily and which suffers from loss of shape recovery.
Another solution which has been discussed in the patent literature involves the concept or adding thermoplastic material to the absorbent matrix. The thermoplastic is typically added as ribers or powder.
It has been intermingled with the absorbent to Xeep the capillaries within the absorbent open, and at varying "` :li76~
level~ with decreased amounts present in the center or most ab~orbent area of the absorbent matrix. In the latter case, thermoplastic is added to establi~h a capillary gradient in which absorbent layers with larger capillaries are presant nearest the body of the wearer.
Example~ of the addition of thermopla~tic can be found in- U.S. Patents 4,082,886 and 4,129,132 lssued to George A. M. Butterworth et al: 3,976,074 issued to Harry G. Fitzgerald et al; 4,054,141 issued to Julius Schwaiger et al; 4,047,531 issued to Hamzeh Karami; 3,545,441 issued to ~unnar Gravdahl and 4,219,024 issued to Donald Patience et al.
The prior art listed above recogni~e~ the desirability of having a capillary gradient with larger capillaries nearest the body of the wearer and smaller capil}aries in the area where maximum absorbency is desired. I~ the absorbe~t mat~ix in the napkin was designed 50 that the smallest capillaries were closest to the body of the wearer, fluid would remain in the area of the smallest capillaries and would not disperse through the rest of the absorbent matrix due to capillary attraction. If a number of large capillaries are near the point of fluid contact and a greater number of small capillaries are farther from that point, then fluid will be drawn away frcm the initial contact site.
In general, the greater the level of unfused thermoplastic material, the higher the amount of shape recovery introduced into the absorbent matrix of the sanitary napkin.
A napkin with a relatively thick layer of large 4~2 ~apillaries readily transfers relatively low viscosity fluid3 such as urine, water, or even blood. It has been recogn~zedl however, that menses i5 a cornplex 1uid with uterine blood being only one component O:e its composition.
AdditionalLy, menses contains cellular dl3bris and a mucus-liXe fraction. It has also been recogni7e~ that the character of menses can differ in composition, viscosity, volume and flow rate from individual to individual and also at diferent times in the menstrual cycle with a given individual. It has also been detenmined that certain women have consistently high viscosity menses and compara~ively low flow volumes.
Since highly viscous menses has been .identi~ied, it has now been discovered tha~ the composition c~ men~es also has a signi~icant effect on ~he transp~rt of fluid ~rom the cover into the absorbent matrix o~ a sanitary napkin. When the viscosity and cellular debris content of menses are relatively low, usually during p2riods of high flow, it passes relatively rapidly through the cover material and into the absorbent matrix; even in cases where the portion of the absorbent matrix adjacent the cover material has relatively large capillaries. ~owever, it has been observed that more viscous, high deb-is-content menses, especially prevalent during periods of low flow, tends to stay on the upper surface of the cover. In addition, particularly when there is little capillary attractive force exerted on the bottom of the cover by the absorbent matrix, the fluid component tends to stay on the surface and 'hen run off the si~es of the napkin. It is believed that earlier a.tempts at designing 64(~Z
sanita~y napXins containing thermoplastic materials have been unsucce3sful because of the failure of the absorbent matrix to draw viscous menses through the cover material.
U.S. Patents, ~,214,58~ issued to Harish A~
Patel and 3,285,245 issued to Charles L. Eldredge et al describe wound dressings in which a thermoplastic fluid pervious'covar is used to an absorbent layer also containin~ thermoplastic~ The Patel patent discloses a wound dressing having a hydrophobic cover, a microcreped absorbent layer underneath the cover and a second hydrophobic cover positioned on the bottom of the absorptive layer. This combination is subjected to embossing by a compactor to provide large locally fus~d discrete portions ~long the cover surface in contact ~ith tho wound. This relati.vely severe compressio~ in ~u~ng is de~igned to provide an irregular top surace for ease o release from the wound area as it heals. The fusing of the major proportion o~ the top surface area also provides a suitable release surface.
The Eldredge patent discloses a surface in which the fusible fibers are drawn through the cover material to p_ovide a soft matt finish and aid in the wicXing of fluid wound exudate along the top surface of the cover and into the main absorbent area through tne cover.
~either of these configuratlons would be particularly useful for a sanitary napkin. In the wound dressins described by Patel, the rapid discharge of fluid would settle on the relativeLy large fused sur-ace since there is no penetration OI fluid in the fused area. The relatively great amount of compression applied over - :1176~02 relatively substantial areas ln Patel also tencls to destroy such deEormability and compressibility as may otherwise have been present. To design a napkin having the Eldredge configuration would tend to provide a competing capillary structure above the cover which would tend to trap debris and prevent fluid transfer into the napkin resulting in a perpetually wet surace after initial discharge.
According to the present invention there is provided a sanitary napkin with a perineal area generally corres- -ponding to the perlneal area of the wearer, the napkin having an absorhent matrix system with the transver~ely disposed fluid permeabLe transEer layer inaluding a th~rmo-plastic material and principal absorbent layer. ~ Eluid permeable cover is pro~ided which has a bod~-Eaaing surface.
A fluld impermeable baf1e i9 positioned be~ween the system and the undergarment of the wearer and is charactexized by at least a portion of the transfer layer being positioned beneath the body-facing surface and spacedly inte~rated in the perineal area to produce zones exhibitin~ greater density relative to the remainder of a transfer layer but retaining permeability in the zones corresponding to the transfer area of the cover. The trans~er area is not less than 0.12 percent of the perineal area.
The sanitary napkin of the present invention has improved comfort and the ability to relatively rapidly transfer viscous menses from the cover into the absorbent matrix. More specifically, the absorbent matrix contains a principal absorbent component characterized by relatively kh/,~i ` 1~764~2 hi~h fl.uid ratentiqn and a second component including comfor-t enhancement capabilities positioned at least in part between the principal absor~ent and the 1uid permeable cover or wrap. The second component is integrated with the cover to provide intimate contact and denslfication of localized re~ions. As ~ consequence, iluid transfer routes are established and fluid is con-veyed to the principal absorbent component.
When used in this specification, a comfort enhancement layer may include the entire layer which in certain con-igurations extends around the sides and at least a part of the bottom o the principal absorbent aomponent layer while the fluid transer layer terminology re~ers only to the posltion of the comor-t enhancement layer betw~en the top of the aover and the absorb~nt on the body facing sLde.

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The invention may be more readily understood by referance to the drawings in which:
FIG. 1 is a perspecti~e view partially in cross section of one embodiment o thQ sanitary napkin of this invention;
FIG. 2 is a cross sectonal view taken along lines

2-2 of FI~. 1.
FIG. 3 is a cross section of a second embodiment of the construction of the sanitary napkin accordiny to this invention; and FIG. 4 is a cross section o~ a third embodiment of the san'tary napkin according to this invention. In all igures like numbers relate to like portions.

According to the embodiment shown in FIGS. 1 and 2 a sanitary nap~in is provided having a fluid pervious cover 10 and a thermoplastic-containing comfort enhancing - layer 14 which surrounds an absorbent layer 15. The comfort enhancement layer 14 has a bottom portion 14b to further improve comfort and a top portion 14a. Attached to the bottom portion 14b is a fluid imparmeable baffle 16.
Garment suspension adhesive lines 17 are centrally longit~dinaLly positioned on baffle 16 and a release llner 18 is removably attached to the bottom surface of the adhesive lines 17. The comfort enhancing layer 14 is preferably coextensive with the cover 10 at the ends of the napXin 13 which are sea~ed, e.g., by ultrasonic bonding as shown by fused l~nes 12 which are inset from the ends 13.
The outer wrap or cover is integrated to the 6~
comfort enhancement layer 14 at l~ast at selected parts of the trans~er layer 14a corresponding to integration sites 11 of the wrap 10. In~egration ref~rs to the bonding of the wrap 10 to at least the tr~nsfer layer 14a at sites Ll at distances not greater than 2 centimetlers apart at least in the perineal area or the napkin.
The perineal area of t~e napkin is that portion of the napki~ abutting the perineal area of the wearer.
This portion, depending on the design o~ the napkin and the positioning of the napkin by the wearer, i5 generally centered longitudinally and transversely and is 1 centimeter wide in the tran~erse direction and 5 centimeters long. Aq will become apparent, lt is desirabLe that at least one and preferably at least ~ to 3 integration sites be present at the napXin sur~ace directly beneath the perineal ar&a of the wearer.
Integration may occur throughout the top of the cover and may be used to bond the layer 14 to the cover 10 which may then be treated as a single unit for manufacturing purposes and this is desirable for ease of processing.
Bonding to accomplish integration can be by .he application of heat, such as by hot calender embossing, or by ul-rasonic means or it can be by mechanical manipulation of fibers with or without heat as, in needling. It is preferred that bonding be by heating means and ultrasonic bondina is particularly preferred.
The bonding, if by heat may be so~e_hing less than fusing such as described in U.S. Patent 3,855,046.

The bonding step may, in fact, produce holes in ~he co~er material itsel whlch m~y extend into the comfort enhancement lay~r depending upon the severity of the bonding treatment, It i5 al~o possible that stray f;ibers may penetrate the cover 10 on occasion and penetration may occur at or ne~r tha area of integration. Larqe ~nounts of this penetration i5 ~ndesirable however, because the body-~acing sur~ace of the cover must be as dry as possible. If large amounts of fiber are present, particularly if this fiber is contiguous over an area, lateral surface wicXing occurs and the surface;produces a highly objectionable wet tactile sensation which is likely to result in the prematur2 discarding of the napkln. Integration of the cover 10 to the trans~er layer 14a of th~ com~ort enhancement 14 alt~rs th~ character o the trans~e~ portion 14a by providing transfer zone~ 21 of increased density and compressio~
which diminish as they extend radially outwardly from the integration sites 11 through the depth of the transfer portion 14a. It should be noted that the part of layer 14a directly under the integration sites may be entirely fused and not form part of zone 21.
These 70nes 21 which are observable and quantifiable by mic~oscopic examination as to '.heir extent and degree of compaction provide conduits for transfer of viscous menses described p-eviously. Transfer occurs i~
these zones Zl where the capillaries are predominantly not greater in size than that of the absorbent layer 15.
Transfer areas 20, illustrated by dotted lines in FIG. 1, are areas which are directly above the transfer zones 21 and indicate the portlon of the cover where fluid :~1'7~;4~

tran~er will first occur from the top of the cover t~rough the layer 14a. These transfer areas 20 vary from being irregular to circular in shape, and may overlap.
There may be portions of the surface of the nap~in which are neither inteyration sites 11 nor transfer areas 20.
These areas lack capillary attractive force to pu~l ~luid through and for that reason, trans~er of viscous, cellular debris and mucoid-containing menses through this portion of the surface of the napkin is extremely slow if it occurs at all. Relatively nonviscous fluid will transfer downw~rd more readily through these portions but will preferentially transer in the transfar areas 20.
These portions which are neither trans~er zones or bond sites in the transfer layer 14a help provide the com~ort enhancement ~eatures o~ the napkin o this invention.
The reason for having in~egration sites with the resultant ~ransfer areas 20 and transfer ~ones 21 beneath the areas of fluid discharge becomes readily apparent with these facts in mind. It has been found that viscous menses of the type previously d~scribed transCer~ when as little as 0.12% of perineal area of the napkin beneath the body of the wearer is transfer area.
This minimal amount of transfer area can be obtained by positioning 2 single integration site in the 1 by 5 cm perineal area.
The effect of integration, with regard to the number and size of the integration sites in _his 1 by 5 cm area is also important. Fluid transfer seldom if ever occurs through the integration sit~. Large intesration sites, Lr~6~

contiguous integration site~ and several closely spaced in~egration sites are ~here~ore ~o be avoided particularly w~n integration ic by using. It is generally pxeferred to maintain individual integration sites more tha~ 0.15 centimeters apart, in any event, because the higher the level of integration the stifer and therefore the less comortable ~he napXin becomes. It has been found that when the fused bond sites are more than 20% of the 1 by 5 cm area on the surface of the integrated cover ~here fluid transfer occurs, there is significant puddling of menses rendering ~he napkin unsuitable for use. It is preferred that if fusing is utilized as the process for integration, the fused area is less than 10~ an~
particularly between 0.5 and 5% of the napki.n cover surface.
Since it is preferred that the transfer layer 14a be integrated wit~ the cover 10 prior to napkin assembly it is easiest to maintain the same integration pattern with regard to spacing over the entire surface 14a zs well as layer 14b. From the standpoint of fluid tran~fer, into layers 14a and 15, howevex, it is apparent that the critical portion for control of transfer area and integration is that part of the r.apki sur~ace directly under and nearest initial fluid discharge, i~e., the perineal area of the napXin defined earlier.
It has been observed that fusing of the comfort enhancing layer 14 particularly at fluid transfer layer 14a prior to integ~ation with the cover 10 increases the efficiency of viscous menses txansfer possibly by increasi.ng the numbex of small capillaries around the ~7~0;~:
integra~ion ~i~es 11. However, fusing tends to stiffen the layer and, therefore a tradeoff of benefit~ results.
It should be noted that the minimum transfer area d~scribed above is based upon the use of a fu~ed transfer lay~r 14a. Fusing as defined herein is the partial softening and~or me~ting o~ a thermoplast~c mate~ial to provide bonds with the thermopla~tic.
The transfer layer may conta~n nonthermoplastic fibers, absorbent fibers such as rayon, superabsorbent rayon, ce1lulos~c fibers or blends of the above.
Suitable thermoplastic fibers are polyester, poly~ropyle~e, acrylic or nylon ~ibers or blends. Crirnped ~ibers add comfort and their use at ~.east at ~ome level is preferred~
I fu~ng is desired the addition o a Low me~ ting point readil~ fusible fiber i~ high~y desirable.
Suitable fus~ble ~bers or this invention are:*Vinyon, a ~inyl chloride/vinyl acetate copolymer sold by Avtex Fibers Inc. o New ~or~, New York; *Eastman 410 amo~phous or crystalline polyester fibers sold by Eastman Che~icc Products, Inc., a Subsidiary of Eas~man ~odak Co., Kingsport, Ten~.; or*Chisso ES a b~component polypropylene/polyethylene fiber sold bv Chisso L~d., Osaka, Japzn, wh_ch due to its differen'ial melting ~oint ~r each component of the fiber/ could be used as ~he only thermoplas~ic fiber as well as in blends w~th other fibers.
The comfort enhzncing layer czn De ~o~~ed by * Trade mark ~'7~4~Z

c~rding or it m~y be airLaid, however, randomized carding i~ pre~erred because it incre~ses bulk and therefore perceivad dry softness to the comfort enhancing layer.
~ he transfer layer 14a has a basi~ we~ght range from 30 to 400 gms/square meter and a thic~ness generally be~ween about 0.1 to about 1 cm. Of cour~e, i~ the e~bodiment depicted, for example at FIG~. 1 and 2 is used, there will be two layers 14a and 14b each having thickness and basis weight characteristic:s within the parameters set forth above. These values may not be identical for layers 14a and 14b however if only thé
transfer layer 14a is in~egrated.
The co~er or outer wrap 10 o~ the napkin of this inventio~ is primarily of a nonwoven thermoplastic web and should b~ of a suf~iclently open structure to enhance the trans~er o~ ~he viscous ~luid menses described above into the transfer layer 14a.
For a cover to readily transfer this viscous fluid according to the teachings of this invention it must be sufficiently open to enhance transfer. While the surface of the cover may be altered by treatment with suitable surface active agents, to aid in the transfer certain cover structures have been found to perform better than others and their performance has been correlated to .he number of small holes present.
Several cover materials were submitted for examination by a Quantimet 900 Image Analyzer made by Cambridge-Imanco Ltd, Cambridge, England. A Bausch and Lomb Model L transmitted llght photomicrographic unit was ~l7~4loz employed to taXa photomicrographs of cover materials ~n~ch had been pre~iously tested. The photomicrographs were examined w~th the Image ~nalyzer pixel size set at 13,7.B
microns.
For a cover to be accep~able no more than 40%
o~ the holes may have a breadth of less than ~7.3 microns, with preferred covers having less than 25~ of ~he holes which are less than 27.3 microns. ~readth ~s def~ned as ~he maximum dimension of the hole measured ~t ~0 to the major axis of the hole.
A second set of measurements which were taken directly on the cover material with a pixel size o~ 3.04 microns revealed that pre~erred cover materials should h~v~
no more than g0 holes/mm2 with a ~readth of Less ~han 13 microns. Generally, ~his latter breadth measurement has been correlated to ~luid retentio~ with~n the ~cover. In other words, a ootential cover material may transfer Clu~d ~ut reta_n a significant amount wi~h~n the cover holes, thus producing a wet feeling surface.
~0 One of the thermoplastlc nonwoven cover materials which meets the first criterion and is acceptable is Sharnet (xL008-30A). Sharnet is a trademark of Inmont Corp., Somervllle, Mass.
A most preferred cover ma.er~al which m~ets bo~h criteria is a uniform spunbonde~ nonwoven web having 3 denler or ~arger llaments. Such a materlal is described - in applicant's Canadian issued Patent No. 1,060,412, issued January 17, 1984 by Appel and Morman.

~764~2 EXAMPLE I
Comfort enhancement as used herein relates to the force needed to compress the cover and the absorbent matrix, i.e~, the transer layer integrated with the cover layer and the principar absorbent layer. For purpo~es of this invention a standard wood pulp fluff layer was used as indicated below as thè principal absorbent layer. This fluff was ftberized in a hammermill and has a basi~ weight of 580 gm/m~ which is a value between that of the standard commercial fluff used for maxi pads and that used for mini pads sold under the NEW FREEDOM trademark by Kimberly-ClarX Corporation of Neenah, Wisconsin. Several

3 x 6 in. 1u blanks were prepared. SeveraL 3 x 3 in.
samples o~ both fused and unfused transfer layers having differing desre~s of integration were also prepared and cente~ed on the ~lu~.
The te~t descri~ed below was run on an Instron Model TM with an integrator unit Model Dl-53 with a compression load cell model CC havins a 2 1/4 in. diameter compression ram.
The transfer layer basis weight used ror a~l samples was 0.0129 g/cm2. The preferred cover described earlier of a ùniform spunbonded polyp_opylene web having 3 denler filaments was intesrated o several samples of the transfer layer by ultrasonic bonding wi,h a 0.07& cm diameter pin with the spacing between integration 'or each sample indicated in the table below. (Thls pin value is + 0.01 cm due to wear encountered on the pin head.) A glycerol water mixture having a viscositv of 700 centipoises at 21~C and a sur ace tension of ;2 + 2 dynes/cm was prepared. Pluronlc F68 a surfacrant made by :~17~0~
Wyandotte Chemical Corporation, Wyandotte, Michigan, a divi~ion of BASF was used to obtain the desired surface ten~ion and a red dye was added. This fluid has proven to be a sati~factory simulation ~or the fluid trans~er characteri~tics of the viscous menses described throughout this disclosure. Ten ccs of this fluid ;~re added through a 3/4 inch diameter ori~ice in a plexiglass blocX
weighing 113.3 gm. The block rested on each sample with a 2 in. diameter circular base with the orifice centered.
After all of the fluid enters the cover the block ls removed withou~ exerting downward pressure. The sample is a~lowed to sit for 5 minutes. Each of the samples was wrapped in 5 by 8 in. sheet~ o~ 2 mil-polyethylene film.
The sample is centered under a 2 lf4 in.
diameter circular Instron ram head. ~he Instron and ~nte~rator was caLibr~ted as per standard procedure and the cross head speed set to 2 in./min. Each sample was individually compressed to 40% of the original dry thicXne~s as measured on Custom Scienti.ic Instruments Thickness Tester Model CS-55-210.
As compresslon occured the force applied to compress and the distance the ram head travsls was - recorded. After compression wa~ accomplished the force was removea by reversing ra~ head direction at the same cross speed thereby providlng a recovery period. The cycle of compression and recovery was repeated an additional 9 times to obtain an e~uilibrium state for each sample tested.
The maxlmum force (F~aX) exerted during .he equilibrium cycle is representative of the condition of .he napkin which has been compressed during use. According -~6-to this tast, comparatively lower values are better because they reflect como~t as a functicn of residual wet compressability.

max 60~ Compression tgm~
nd Spacing With Fused With ~nfu~ed tcm) Transfer Layer 0.251 6810 7470 0,359 7730 5960 0.539 6010 65~0 0.718 686g 471~
0.898 4831 4210 101.796 3451 2840 For comparison a napkin blank with fluf only was tested and yielded a value o~ ~610 gms. The addition of conven~ional cover materials does not significantly alter this value. Values greater than 7000 gms ar~ no~
desirable.

EXAMPLE II
During the test performed to produce the data set forth in Example I the Instron data were evaluated at the 50~ compression points on the first and the last, i.e., equiLibrium cy~les. mlhe ratio between the forces at 50~
compression is a measure of the resistance of the pad to permanent distortion.

T.~BLE 2 Ratio of Feq./Fl Bond Spacing cm. Fused Unfused 0.251 0.171 0.178 0.359 0.186 0.159 0.539 0.237 0.210 0.718 0.245 0.207 0.898 0.3~4 0.235 301.796 0.320 0.3 5 oz For comparison purposes fluf~ only had a value of 0.068 and when conventional cover materials were placed o~er the fluf~ no significant change was observed when compared to the flu~f alone.
It should be noted that value~ greater than 1/10 are desirable and especially preferred are values greater than 1/5. The greater this ratio the less the change in a wet pad duri~g use.
Since in all instances in the above examples the bond points-were arranged in square patterns, the amount of fused area can be determined by calculating the area of the embossing pins contacting the surface. In the c~se of the closest spacing set forth, assuming the maximum possible number of used sitas within the perineal area o the napkin, the amount o~ ~used area is about 9.6% wi.th the variance again due to variabiLity in pin head diameter. This particular configuration has lost a substantial amount or comfort and softness when compared to the wider spacing set forth in the Table above and from the standpoint of increased tactile satisfaction by the wearer, this number provides a realistic maximum.
The principal absorbent layer 15 may be any conventional absorbent used in feminine protection products such as cellulosic fibers or the like and may contain absorbency additives, e.g., superabsorbents. One useful material for the principal absorbent 15 is described in ~.S. Patent 4,100,32.. This material is a turbulently coformed mixture of airlaid meltblown microfibers and a cellulosic material such as wood pulp fluff. The absorbent activity may be heightened by the aadition of absorpti.ve materials having higher absorptive ~'764~;~
capa~ity per unit weight and the~e materials such as su~erabsorbent materials may bo used as the primary absorbent to the exclusion of, or in conjunction with conventional cellulosic absorbent~ within ~he ~cope of this invention.
The embodiment depicted in FIG. 3 is identical ~o that in FIGS. 1 and 2 except ~hat thle absorbent portion containing the thermoplastic 14 along with the ` cover 10 is folded onto itself on the bottom of the absorbent area at 14c to provide additional comort enhancement. The garment attachment adhesive 17 is shown attached to`the baffle 16 outside o the cover wrap 10.
A release liner 18 is conventionally provi.ded to protect the attachment adheqive. Extra comfort enhancement layers can be added under the flu~f and, in act, a se~ies ~f coterminous comfort enhancement layers may be used. These laye~s can also ~e coterminous with the principal absorbent layer within the scope of this invention.
FIG. 4 illustrates an embodiment which is different than the other two embodiments because, in this instance, the thermoplastic is present in the same layer as the conventional absorbent portion 154 but is present in a higher percentage near the body facing surface of the napXin. Although the currently preferred embodiments are those depicted in FIGS. 1, 2 and 3 because of the simplicity of manufacture this embodiment is also contemplated by this invention.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A sanitary napkin with a perineal area gener-ally corresponding to the perineal area of the wearer in-cluding:
an absorbent matrix system having a transversely disposed fluid permeable transfer layer including a thermo-plastic material and a principal absorbent layer;
a fluid permeable cover, said cover having a body-facing surface; and a fluid impermeable baffle positioned between said system and the undergarment of the wearer characterized by at least a portion of said transfer layer being positioned beneath said body-facing surface and spacedly integrated in the perineal area to produce zones exhibiting greater density relative to the remainder of said transfer layer but retaining permeability in said zones corresponding to a transfer area on said cover;
said transfer area being not less than 0.12 per-cent of said perineal area.

2. A sanitary napkin according to claim 1 wherein said transfer portion is coterminous with said cover and integrated throughout the coterminous surfaces.

3. A sanitary napkin according to claim 1 wherein integration occurs at sites between 0.15 and 2 centimeters.

4. The napkin according to claim 1, where-in the transfer portion contains fused thermoplastic mater-ial.

5. The napkin according to claim 1 wherein the comfort is defined as resistance to permanent distortion as measured by Feq/Fl which is at least 1/10 at 50 percent com-pression.

6. The napkin according to claim 1 wherein com-fort is defined as FmaX at 60 percent compression during the tenth compression as a measure of wet compressability and is less than 7000 gms.

7. The napkin according to claim 1 wherein the absorbent portion is a coformed airlaid mixture of melt-blown thermoplastic and cellulostic fibers.

8. The napkin according to claim 1, 2 or 3 wherein the transfer portion is a separate part of a comfort enhancement layer and extends around the side edges and at least a part of the baffle-facing side of the absorbent portion.

9. The napkin according to claim 1, 2 or 3 wherein the integrated cover-transfer portion is a separate layer and extends around the side edges of the nap-kin and at least a part of the baffle-facing side of the absorbent portion and is folded in a double thickness on said baffle-facing side.

10. The napkin according to claim 1! 2 or 3 wherein the transfer portion contains between about 40 and 100 percent by weight of thermoplastic material.

11. The napkin according to claim 1, 2 or 3 wherein the absorbent matrix is formed as a uni-tary layer having thermoplastic material with higher levels of thermoplastic present in at least that part of the ab-sorbent matrix adjacent the cover.

12. The napkin according to claim 1.

wherein integration is not greater than 20 percent in the perineal area of the napkin.

13. The napkin according to claim 1, 2 or 3 having a plurality of mutually coterminous layers at least one of which is a principal absorbent layer.

14. The napkin according to claim 1, 2 or 3 having a plurality of coterminous comfort enhancement layers.

15. The napkin according to claim 4, 5 or 6 wherein the transfer portion is a separate part of a comfort enhancement layer and extends around the side edges and at least a part of the baffle-facing side of the absorbent portion.

16. The napkin according to claim 4, 5 or 6 wherein the integrated cover-transfer portion is a separate layer and extends around the side edges of the napkin and at least a part of the baffle-facing side of the absorbent portion and is folded in a double thickness on said baffle-facing side.

17. The napkin according to claim 4, 5 or 6 wherein the transfer portion contains between about 40 and 100 percent by weight of thermoplastic material.

18. The napkin according to claim 4, 5 or 6 wherein the absorbent matrix is formed as a unitary layer having thermoplastic material with higher levels of thermo-plastic present in at least that part of the absorbent matrix adjacent the cover.

19. The napkin according to claim 4, 5 or 6 wherein integration is not greater than 20 percent in the perineal area of the napkin.

20. The napkin according to claim 4, 5 or 6 having a plurality of mutually coterminous layers at least one of which is a principal absorbent layer.

21. The napkin according to claim 4, 5 or 6 having a plurality of coterminous comfort enhancement layers.

22. The napkin according to claim 7 or 12 having a plurality of mutually coterminous layers at least one of which is a principal absorbent layer.

23. The napkin according to claim 7 or 12 having a plurality of coterminous comfort enhancement layers.

24. A sanitary napkin with a perineal area generally corresponding to and positioned beneath the perineal area of the wearer in use comprising:
(a) a fluid permeable cover with a body contacting surface;
(b) an absorbent matrix system including a principal absorbent portion and a transfer portion in-cluding thermoplastic material;
(c) said transfer portion positioned between said cover and said principal absorbent portion and in fluid conductive contact between said cover and said principal absorbent portion and integrated at spaced apart sites with said cover, at least in the perineal area, to produce zones of greater density and enhanced fluid conduction relative to the remainder of said transfer portion; said zones corresponding to a transfer area on said cover, said transfer area being not less than 0.12% of said napkin perineal area; and (d) a fluid impermeable baffle adjacent said absorbent matrix system having a garment facing surface and an absorbent-matrix-system-facing-surface.

25. A sanitary napkin according to claim 24 wherein said transfer portion is coterminous with said cover and integrated throughout the coterminous surfaces.

26. A sanitary napkin according to claim 24 wherein integration occurs at sites between at least 0.75 and 2 centimeters apart.

27. The napkin according to claim 24 wherein the Feq/Fl is at least 1/5 at 50% compression.

28. The napkin according to claim 24 wherein the principal absorbent layer is a coformed airlaid mixture of meltblown thermoplastic and cellulosic fibers.

29. The napkin according to claim 24 wherein the transfer portion is a separate part of a comfort enhancement layer, said comfort enhancement layer extending around the side edges and at least a part of the surface of the principal absorbent portion opposite the surface in fluid conductive contact with the transfer portion.

30. The napkin according to claim 24 wherein the transfer portion is a separate part of a comfort en-hancement layer and extends around the side edges of the napkin and is folded In a double thickness at the surface of the principal absorbent portion opposite the surface in fluid conductive contact with the transfer portion.

31, The napkin according to claim 24 wherein the transfer portion contains between about 40 and about 100% by weight of thermoplastic material.

32. The napkin according to claim 24 wherein the principal absorbent layer is primarily cellulosic material.

33. The napkin according to claim 24 wherein the absorbent matrix is formed as a unitary layer having thermoplastic material with higher levels of thermoplastic present in at least that part of the absorbent matrix adjacent the cover.

34. The napkin according to claim 24 wherein integration is not greater than 20% of the perineal area of the napkin.

35. The napkin according to claim 24 wherein integration is not greater than 10% in the perineal area of the napkin.

36. The napkin according to claim 24 wherein integration is between 0.5 and 5% in the perineal area of the napkin.

37. The napkin according to claim 24 wherein the cover material has no greater than 40% of its pores with a breadth of less than 27.3 microns.

38. The napkin according to claim 24 wherein the cover material has no greater than 40% of its pores with a breadth of less than 27.3 microns and no greater than 90 pores/mm2 with a breadth of less than 13 microns.

39. The napkin according to claim 24 having a plurality of mutually coterminous layers at least one of which is a principal absorbent layer.

40. The napkin according to claim 24 having a plurality of coterminous comfort enhancement layers.