ABSORBENT PAD

Abstract: The absorbent pad (10) comprises a layer (11) of a water-impervious backing material, a water-absorbing layer (12) comprising at least one super-absorbent polymer and a water-pervious sheath (13). The water-absorbing layer (12) is received within the sheath (13) and is movable therein but, prior to use, is frictionally engaged to prevent such movement in normal handling. When the absorbent layer (12) is wet from use its weight makes it easy to move the layer from the sheath (13). Both layers of one end of the sheath (13) are adhered to the backing material (11) adjacent that end. The layers of the sheath (13) are adhered to the backing material (11) at its other end only at the outermost extremities of that end.

Description: ABSORBENT PAD Technical Field of the Invention Thi s i nvention rel ates to an absorbent pad f or tiie absor.btion of bodily fluids, and to a method of producing such a pad. The absorbent pad according to t i ven ion compri ses a lo itu inally extending layer of a water- i πp e r v i o u s bac in • . a t e r i a 1 , a longitudi nal ly exten ing ° water-absorbin layer, and a water nervious sheath. The water pervious sheath is a here to the layer of backing rate rial and the water absor ing layer is recei ed within the sheath so that relative longitudinal πove-nent between the sheath a d the water absorb g layer is difficult when 5 the latter is d y, but easy hen it is et. The pad is partic l arly adapted for use n the care of uri nary incontinence. Background of the Invention Λ variety of attempts have been ■-■taάe to produce absorbent ads suitable for t e care of urinary ncontin ce. Some of the parameters which πust be considered are absorbtive ca aci ty and rate, protection against leakage a d odor emission, metho of isposal an earer comfort which can 5 i nvol e ulk, wei ht, exertion of pressure n local ized areas of the s i and relative feeling of dryness. The rior art is inundated wi h pads incor ora i methods of dealing with at least one of these consi erations, but is de oid of a pad ic deals s tis actoril it al l of 30 the i . united States patent '!o. 4,293,609 grante October 6, 1 Q R1 to Pobert E . Erickson discloses an absorbent laminate comprising a ater-swel l abl e or l htly cross-l i n ed " hydrophi l ic polymer, preferrably an essenti l ly water soluble nolyel ectrolyte in the sal t form, and layers of a wicking substrate. Erickson further discloses an absorbent BAD ORIGINAL pad comprising the laminate descri ed above, at least one layer of a wicking substrate, a water- i mpervi ous bottom sheet and a water-pervious top sheet. 5 United States patent Ho. 4,176,567 granted December a , 1979 to Julian II. Herring discloses an absorbent pad comprising an absorbent layer, described as a film of water-swel 1 abl e gel-forming cross-linked olyacryl te polymers mechanically bonded to a crεped substrate, a bottom sheet, a top sheet 10 and any number of layers of filler material . According to the reference, parallel e ges of t e ater-i pervious bottom sheet may be folded upwardly and inwardly toward each other and then sealed, the pad being constructed in a manner whereby the ridges in the creneH substrate of the 15 absorbent layer di ect the flow of liqui deposited therein toward the sealed edges of the bottom sheet. United St tes patent .. o . 3,903,889 granted Septem er 9, 1975 to Dav To rr d scloses a liquid-absorbe . t product 20 con rising a o articulate liquid -absorbent gel -formi ng material , modified guar gum being preferred, which can be ad ered to a i ional co onents means of a ater solubl adhesive. The ".89 patent further discloses the use of the absorb t product escri e abo e it a liqui - 25 pervious o y cont cti laye nd a ou er la r, which as been terproofed at one or b h si es, to form an absorbent pad ./hich s described as disposabl by flushi g in a toi 1 t s s em. 30 United States patent ' 'o. 3,683,919 granted August 15, 1972 -co Myron B. El l s discloses a sani tary napki n havi ng a conventional high wet-strength, non-woven cover which can readily be torn longitudinally into two substantially equal portions to release the absorbent core from the encasing 35 cover thereby permitting flushing away of the core and the cover separately in a conventional -water closet. BAD ORIGINAL Summary of the Invention The a sorbent pad accordi ng to the i nstant i nvention comp i ses a lon itudinally extending layer of a water- impervious backing material , a longitudinal ly extendi g water-absor ng l ayer compri si ng at least one super- absorbent polymer that is capable of absorbing at least five times its ry weight of water and a water- per ious sheath, the water-absorbing layer being received within the sheath. Further, a pad accordance .nth the invention is c o n s t r u c t e d in a such a ma ne that h ter-absorbi g l yer s longitudi ally movable within the sheath but, ri o to use, i s f ricti nally engaged the e th t o a n extent necassary o pr ve t such move ent i n n o r r a 1 handl ing. '< •■ ' .. e n the absorb nt l ayer is wet fro use its w i ht i s greatl y i ncreased a nd i ts tendency f or l on itudinal movement is correspon ingly increased. Roth layers of one end of the sheath are adhered to the backing materi al a j a c e n I a t e by mea s of a heat seal or appropri te adhesive. The layers of the sheath are adhered to the bac i ng mate ial at i ts other end only at the outermost extremities of that end. Accordingl , afte use, hen the pa i s rippe by the ful l seal e e x^ a d downward motion is imparted thereto toward the partial ly seal e end an that ion i s sud enl s o pe , t e absorbent layer is forced by its inertia from its position i n the sheath into a wai ting recent icle. Addi tionall , since the water-absorbent layer comprises water-di spersi bl components, it may be rienosited s desc i e above into a standard toilet and subsequently flushed away without fear of clogg ng sewage or septic systems. Brief ϋ e s c r i p t i o n of the D a i gs Fi ur 1 i s a pl an i w of a ad accordi n to he i nvent on. Figure 2 i s a bottom plan view of a portion of the pad of Fi ure 1, namely a sheath with a water-absorbing layer BAD ORIGINA received within the sheath. Figure 3 i s a view, with parts broken away to show details of construction, of the water-absorbing layer of the pad of Fi gun Figure 4 is a view of an alternate water-absorbing layer for a pad according to the invention. 10 ι αure is a view of the bottom of the pad of Fi g ure 1 The first major surface 25 of the backi g material layer 11 is seen in Figure 1 where portions of the sheath 13, namely 35 a layer 2?> having a major surface 29 and a layer 30 having a major surface 31 (Fi ure 2) , have been broken away. The major surfaces 31 and 2? (Fiηure 1) constitute second and first major surfaces, respectively, of the sheath 13. The major surface 25 of the backing layer 11 faces the major surface 31 (Figure 2) of the sheath layer 30 i n the pad 10. The sheath 13 i s composed of a si le layer of a olyes r, non-woven fiber at h he ed es thereof overlapped as indicated at 32 to form the layer into the shea h 13 i n t e a 10 he s h e a t 13 i s comoressed a j cent its si s 1 " and 17 s that the opposed su faces thereof constitute apparently separate sheath layers 28 and 30, as previousl desc i ed. The water-absorbi g layer 12 is composed of a layer 33 of a pleated la inate of at least one cellules ic tissue an . a cross-linked starch-acrylic graft copoly er, a cross-linked acryl ic polymer, or a blend of the two -which, in, any case, is capabl o absorbing at least five times its own <.ir weight of .,ater. The layer 33 is wrapped in three layers 34 of a cellulosic tissue. There are a cuate c ts , as i ndicated at 35, i the pleated lam nate layer 33, which form flaps 3fi attached to the laminate layer 33. '-.hen the fl ns 3ή are fol ded away from the cuts dicated at 35 there are openin s through the la ina layer 33. It has b een f ound that a l ami nate of the ty e desc ibed, articularly when the openings are of opti um size and constitute an optimum proportion of the total surface of the la i ate, is pecul iarly effective at pic ing up and hol ing, even under substantial pressure, the discharge of one who suffers from urinary incontinence. The water-absorbing layer 12 can be produced as described i n published application PCT/US82/00312, .which application also discloses the optimum ratio of open area to total area and the optimum sizing for the openings. Sui table cross- l in e acr lic polymers n m e ho s for thei nroduction are disclosed in U.S. patent Mo. 4 , 117 , 1 . while suitable cross-l inked starch-acrylic graft c olymers and methods BAD ORIGIN for their production are disclosed i U . S . patent fio . 4,076,673. Preferably, the polymers and c olymers are o eraMe to absorb at least 25, and, mos desirably, a l east 40 ml o " a 1 ercent y ei h aqueous sodium chlor de solution per gram of the polymer or copolymer. Prior to use of the pad 10, the water absorbing layer 12 t n e r e o f i s c m a ati vely l i gh , a n ^ i s e ecti ly ss uu ppoo tt tt hh rr ee ii nn b . y.. t •_h.,e._ s _,h • .e ,.a „ •_h .. 1 _.3.. a _. n.,.. t „h ..e ._ w .. a.. t „__e.. r , i rip e r v i o i u s ac i material layer 11 i its i n t u r n ε d idges 2 ^ and 27. T e l yer 1 i s m vable lon itudi all A laminate layer ΛQ s shown in Figure 3. The layer 40 is a ful l equivalent for the layer 33, having cuts 35 and flaps 35, and differing only in that it is composed only of upper and lower layers Λl and 42 of a cross-linked starch-acryl c graft copolymer l am ate between two l a e rs o f a cel l ul osic ti ssue; the l a ers 4 i and 42 are a hered together to form the laminate layer D Λ i r lai s ets o cel lulosic fibers, usual l of finely ou d wood, are Known. It is also known that particles of d supe -absorbent poly m e r c e c o d e p o s i t e d i t. h cel lulosic fibers as they are being formed into sheets by 0 the a -l.-i ing process so that the ultimate product is an i 1 a i n cell losic f i I. e r sh et w i t h the ol m e ticl s distributed therethrou h. Such an absorbent sheet can. be used in lace of he water-a sorb i g layer 12 of the pad 10. The cellul sic fibers f ai laid sheets, however, are 5 compara ely bulky and, therefore, are more likely to clog sew ge s stems i to wh ch they a e flus ed than e t e rev ously described water-abso bing layers 12. They are, therefore, less desirable for use in a pad according to the πstant invention, because easy d sposabi 1 i ty by flushing !0 i s an im orta t fea ture o f a a a-c c o r d i n g to the n v < ■ _ rt t i o n . . H 1 c p o uce si m n 1 y t i n th n polyethylene shee material to an a propr ate s i ._ e am 1 5 si'.π., l ac ng a a r p r v i o u s sheath i t a ,/ a t e r absorbing layer received therein on tiie cut sheet, folding e ges o the cu sheet over the e es of the sheath, and heat s al ing o gl n he s n e a t h to the cu sheet as indicated at 22, 23 and 24 in Figure 1. The seals indicated 0 a t 22, 23 and not onl l oc the sh ath to he olyeth l ne sheet material, but also holn the edges 25 and 27 of the polyethylene in their folded-over positions . here they support the sheath 1.3 w th the water absorbing layer 1 therein in the pad 10. 5 The second 'Ojor surface 3 of the backing material layer 11 is shown in Fig re 5 and is opposed to the major surface 25 (Fi ure 1) . Affixed thereto is a pressure sensitive a hesi e strip 44 rotected by a stri pabl cover 45. For use, the co r 5 i s removed fro the adhesive s ri 4; the pad 10 can then be secured to an under rment (not 5 illustrated) of the user. It will be apparent that various changes and modifica i ns c a n f r o t h e s ~ e c i ie ails of : . e i n sSUa n t invention as shown in tiie attach d drawings an described 10 i n con ection the e i th. For example, while the w te i pervious layer 11 has been de scri ed as a polyethylene sheet, any other thin, flexible material that is water- i ervio s in the sense t t it is capable of revent g l eakage the re tiirough in ordinary use of a pad according to 15 the i nv ntion c n be use . Other p o 1 y o 1 e f i n s , vi nyl chl ori e-vi ny 1 i ene chloride conolymers and even cellophane coated to impart the requ site degree of impermeability to water are examples of other suitable material s. Similarly, -. ■ bile the water pervious sheath 12 has been described as a 20 olyes er, non -woven fi er mat, other -a rial s can be used, for example nolyolefin non-woven fiber mats, the only requisi te s e i n g t h t t h e s h e a t h w a t e r - π e r v i o u s sufficiently strong and water-resistant that it is capable o s p orting the wa er-absor in layer 12 i the pad 10 25 pr to and during use. Other changes and modi fic tions • il l oe apparent to those skil led in the art and can be ma e w i t h o u t e artin fro \-\ the spi i t a sco h e invention as defined in the appended claims. 30 35 I BAD ORIGINAL

Claims: Clai s 1. A pad for absorbing body fluids, said pad comprising a l o gi tudi al ly extendi ng l ay r h vi ng o o o s e majo s urf aces f a w a t e r - i -x. p e r v i o u s backing ma ial , a longitud nally extending water-absorbing layer having first a d seco major su faces and generally paral lel si s, sai d layer comprisi g at least one su e -abso bent polymer that is capabl of absorbing at least fi e times its dry weight of water, mό that is ph siologically acceptable for external contact with tiie human body, and a water-pervious s heath ha i n gene al ly paral l e l s i des , a i s su statially closed end and a second substantially n end, said water-absorbing layer being received within said sheath, said sheath being adhered to said backing material l a , and s i d backing ma erial lay r bein so s i z e ^ , relative to sai d sheath, that it constitutes a .barrier to the flow of a fl i from all portions of the *irst major s face of. sai ter-ahsorυ i g layer in a di ection normal to the major surfaces of sai l backing material layer, said water-absorh nπ layer being so received within said sheath th t r l tive longi tudinal movement between the t./o is difficult when said layer is y , /!ιile the mo.-'en t ^ of s a i d l er, hen w e t , a n d w hen the a i s ove longi udinally toward the second end of said sheath and is sto pe-' 1 , causes relative longitudinal mo , 'eme,nt between the two, enabling easy removal of said layer from said sheatn, and s a i ' sheath havi g sufficient wet strength that it is capable of supporting said water-absorbing layer, when wet, el tive to s i bac ing l yer. 2. Λ aύ as c 1 a i m e d i cl aim 1 herei n sai n h a c k i n η material la er nas opposed generally parallel edges which extend upwardly and i w rdly towar cne-another across a portion of sai s e t and a corresponding portion of the sec a j o r s rface of sai d ater-absor ng l yer containe therei n. BAD ORIGIN 3. Λ pad as claimed in claim 2 wherein both layers of the first end of said sheath are sealed to the adjacent portion of said backing material layer. 5 . Λ pad as cl ai ed i n cl ai 3 herei n the outer extremi ies of both layers of the second end of said sheath re se l e to tiie a cent ortions f sai b c in mat r al . 10 5. A pad as claimed in claim 1 wherein the super-absorbent ol e is select d from the roup consisting of cross- 1 inked acrylic polymers, cross-linked starch-acrylic graft copolyπers and blends of the two. 15 g. a'-* as claimed in claim 2 wherein the suner-arsorbent oly er is selected from the g r o u o c o n s i s t i n ~ β f cross- 1 inked acryl ic polymers, cross-l inked starch-acr lic graft copolymers and blends of the two. 20 7. A pad as claimed in claim 3 wherein the super-absorbent p lymer is selected f om the rou consist of cross- 1 inkerf acryl ic polymers, cross -linked starch -acryl i c graft copolymers and blends of the two. 25 .g . . • ;-ad as claimed in claim 4 wherein the super-absorbent pol me is selected om he rou consistin of cress- 1 i nke-- acrylic polymers, cross-linked starch-acrylic graft copolymers an blends of the two. 30 g. A pad as claimed in claim 5 -./herein the su er-absor ent π o 1 n e is a la inate on a tissue sheet. 10. Λ pa as claimed in clai G wherei the super-absorbent polymer is a laminate on a t ssue sheet. 35 11. Λ pad as claimed in claim 7 wherein the super-absorbent olymer is a laminate on a tissue sheet. BAD ORIGINAL 11 12. Λ pad as clai ed in clai 3 w tie re in t'">e super-absorbent polymer is a la ina e on a tissue sheet. 13. A pad as claimed in claim 5 where n the super-absorbent polymer is intimately associated with the fibers of a sheet of i nter^eshed cellulose fibers. 14. Λ a as claimed in claim 5 wherein trie s r-a sorbent pol mer is i ti ately cssoci ed with the fibers of a sheet of cellulose 1 niie s. 15. pad as cl aiπed in claim 7 wherein the super-absorbent polymer is i ti m ately associated wi h the fibers of a sheet f intermeshed cellulose fibers. 15. Λ .ati as claimed in clai'" ■" wherein the super-absorbent polymer is intimately associate'! w h the fibers of a sheet of inter eshed cellulose fibers. 3ΛD ΘR.Θ.NAL

Inventors: MITCHELL WINALEE G, MITCHELL, WINALEE, G.
Applicants: TRANQUILITY PROD INT, TRANQUILITY PRODUCTS INTERNATIONAL, INC.
Application year: 1985
Main classification: A61F13
IPC codes: A61F5, A61F13, A61L15