MXPA98001053A - Disposable absorbent article with capacities of adjustment and transfer of flu - Google Patents

Abstract

An absorbent article comprises a liquid-permeable upper sheet, a liquid-impermeable back sheet fixed to the upper sheet, an absorbent core of a combination of material placed by air, wet-laid and super-absorbent material, the core being placed between the sheet upper and the backsheet to absorb the fluid, and wherein the core includes an elongated, cylindrical, raised portion, for improved contact with a user, and a linen material that encircles at least a portion of the raised portion of the nose.

Description

DISPOSABLE ABSORBENT ARTICLE WITH CAPABILITIES OF ADJUSTMENT AND TRANSFER OF FLUID BACKGROUND OF THE INVENTION The present invention relates to a thick, disposable absorbent article, which allows for increased fit to the body and improved fluid handling. More particularly, the present invention relates to a catamenial pad having a flexible raised strip consisting of an oriented, absorbent plastic network system, or a "canvas" material in combination of layers of materials and absorbent acquisition and transfer core; where the core is able to uncouple the back sheet on the back of the product. This invention is also intended to protect disposable diapers, pantiliners, incontinence articles, sanitary napkins and the like. Conventional sanitary pads or sanitary napkins comprise a liquid-permeable topsheet, a liquid-impermeable backsheet attached to the topsheet, and a relatively flat absorbent core for storing fluid, positioned between the topsheet and the backsheet. However, conventional pads have several disadvantages in that when used, they become deformed or disjoint, and do not provide reliable adjustment or protection to the user. Usually, the total shape of the pad is integral, being restricted by the shape of the panty and will not move to conform to the movements of the users. In addition, as the pads deviate and deform as the user moves, these pads may drip.

Therefore, it is an object of the present invention first, to provide a product which has a canvas material which can be hydroentangled and filled with fibers to provide a sustained fit to the body; second, to provide a combination of tissues placed by air and placed wet with a superabsorbent, which serves as a unique system for fluid acquisition, distribution and storage; and third, to provide a core that is capable of uncoupling from the backsheet either partially or completely, in a separate I rear of the product to allow a maximum lift during the use of the product. The attachment of the upper sheet and the back sheet is designed in such a way that the core is unrestricted by the adjustment of the pantyhose and can move with the body.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the present invention, there is provided an absorbent article comprising a liquid permeable topsheet; a liquid impermeable back sheet attached to said top sheet; an absorbent core of a combination of material placed by air, wet laid and superabsorbent material, the core being placed between the top sheet and the back sheet to absorb the fluid, and wherein the core includes an elongated, cylindrical, raised portion, for improved contact with a user; and a canvas material surrounding at least a portion of the elevated portion of the core. According to a further aspect of the present invention, there is provided an absorbent article comprising an upper sheet impervious to liquid; a liquid impermeable back sheet attached to the top sheet; an absorbent core placed between the upper sheet and the back sheet, wherein the core consists of the combination of tissues placed by air and placed in wet with superabsorbent and comprises an acquisition layer, a transfer layer and a storage layer, an elongated, elevated portion, which acts as the core acquisition layer and contains fluid transporting fibers; a formed tissue strip which acts as the transfer layer and lies within the elongated strip and provides a channel for the fluid from the acquisition layer to the storage layer; means for decoupling the core from the back sheet, in a later portion of the article to rise, such that the core is not restricted by the adjustment of a fixed pantyhose and can move with the user. As used herein, the term "disposable absorbent article" refers to articles that absorb and contain body exudates, and more particularly refers to articles that are placed against or close to a user's body to absorb and contain the different exudates that are discharged from the body (eg, menstruation, blood, urine) and whose articles are intended to be discarded after a single use (ie, they are not intended to be washed or otherwise restored or reused). A preferred absorbent article of the present invention would be used in a sanitary napkin or catamenial pad. As used herein, the term "sanitary napkin" refers to an article that is worn by women, adjacent to the pudendal region and which is intended to absorb and contain menstrual fluids and other discharges from the vagina. A superabsorbent is defined herein to provide materials that are capable of absorbing body fluid in amounts that correspond on either side from several times up to 60 times its own weight. Throughout the description the "Z direction" will be defined as the direction that is orthogonal to the plane of the sanitary napkin when it is in a flat, projected position. The axis of the Z direction is generally oriented towards the user, while the sanitary napkin is used. The X-Y plane is orthogonal to the Z-axis axis, encompassing the longitudinal and transverse axes and is coincident with the plane of the inward facing surface of the backsheet when the sanitary napkin is in the projected, planar position. "Canvases" are defined herein to imply an oriented plastic network that can be made with varying flexibility. As used herein, "pore size" is the wet pore size as measured according to the United States patent entitled "Item with fused layers" from Cree.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described by way of example and with reference to the accompanying drawings in which: Figure 1 is a pad according to the present invention. Figures 2 (a) to 2 (c) are several embodiments according to the present invention. Figure 3 shows a pad having a Z-fold according to the present invention. Figure 4 is a perspective view of a pad with a means for controlling decoupling according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED MODALITY It is an object of the present invention to provide a disposable absorbent article or catamenial pad with superior fit and fluid handling capability. In the description of the present invention, a disposable absorbent article 10 is provided which has a top sheet 12 permeable to the fluid, preferably of a continuous plastic material. A backsheet 14 impervious to the fluid, preferably of polyethylene film, and an absorbent core 16. The top sheet and the backsheet are preferably bonded together, either directly or indirectly through intermediate materials. The top sheet is docile, soft feeling and non-irritating to the user's skin. In addition, the top sheet is permeable to liquid allowing it to quickly transfer liquids through its thickness. A suitable top sheet can be made from a wide range of materials such as formed thermoplastic films, apertured plastic films, porous foams, cross-linked foams, natural fibers (e.g., wood fibers or cotton fibers), synthetic fibers (e.g. , polyester fibers or polypropylene fibers) or from a combination of natural fibers and synthetic fibers, with the films formed being preferred. Preferably, the top sheet of a continuous plastic material is made, such as the film formed with openings as shown in U.S. Patent Nos. 4,342,314 and 4,463,045. In addition, the upper sheet is hydrophilic in such a way that it helps to transfer the liquid more quickly through the upper sheet. The backsheet is impermeable to liquids and is preferably manufactured from a thin plastic film, although other liquid impervious materials may also be used. The backsheet prevents the exudates that have been absorbed and contained within the absorbent core from wetting the article attached to the absorbent article, such as a panty in the case of a catamenial pad. Examples of the materials used for the backsheet are polymeric materials, such as polyethylene or polypropylene. Also, the backsheet may comprise a woven or nonwoven material or mixed materials such as a nonwoven material coated with film. An illustrative back sheet is a polyethylene film one thousandth of an inch thick. The top sheet and the back sheet are joined together in any suitable manner. The top sheet may be suitable directly to the backsheet with an adhesive or other suitable means, or the top sheet may be secured indirectly to the backsheet, the upper sheet being fixed to intermediate members, which in turn are fixed to the back sheet. The absorbent core is placed between the top sheet and the back sheet. The absorbent core provides an additional benefit to the invention and if it should as a single fluid acquisition and distribution system. The core must be generally compressible, conformable and non-irritating to the user's skin, and capable of absorbing and containing liquids and certain exudates from the body. The preferred core material according to the present invention is a layered combination of air-laid and wet-laid materials and superabsorbents, and contains a gelling absorbent material known as AGM 28, which is a product based on starch that swells when it gets wet. The core 16 is composed of 3 parts, each having different properties. The first part, closest to the body is the acquisition layer 22. It is in fluid contact. Then the second layer, the distribution transfer layer 20 transports the fluid to the third layer, the storage layer 18. The pad of the present invention is preferably a core tube. A core tube is a tube-like element that is placed on a thin pad as described in U.S. Patent 4,425,130 to DesMarais. A network oriented, polymeric, or canvas tube material is provided on the tube-like element to a tube according to the present invention as shown in Figure 1. This is responsible for the sustained fit to the body, the elasticity and handling of increased fluid. The canvas system 24 is preferably a porous polypropylene plastic and is formed in the form of an elongated cylindrical tube, which is designed for optimal body contact. This linen tube is on and fixed to the ultra-absorbent storage layer 18 of the core. The canvas maintains the shape of the tube and prevents it from collapsing when it is wetted or compressed. A polyester fiber padding (not shown in Figure 1) provides cushioning within the canvas tube, since the canvas is relatively stiff, thereby allowing the product to be stretched in the Z direction. This canvas tube also maintains its shape when it gets wet, due to its hydrophobic nature. Therefore, the user always feels dry. Therefore, even when the pad is saturated, the canvas will continue to allow additional fluid acquisition, and adjust because an open pore structure is maintained within the product due to its porosity. The canvas allows the contact of a sustained body along the 3 important regions of the body: the introitus, the perineum and the groove between the buttocks. The use of a tube, elevated, highly flexible and covered with canvas provides contact to the body held in the three critical areas of the body, independent of the position of the panty and the movement of the user. Once the fluid has been acquired through the insert. The fluid is transferred to the core of the product, where it can be absorbed and stored away from the body, keeping the user dry. The canvas can be hydroentangled with fibers. This is accomplished by entangling hydrophilic and absorbent fibers within the canvas, using a battery of pressurized water nozzles, the vuales force the fibers into the canvas network. When hydroentangle, the canvas can provide superior fluid handling benefits since these fibers, depending on their selection, allow directional movement of the fluid along the canvas and provide capillaries for a temporary storage area of the fluid until the fluid moves. fluid to the storage portion of the core. Once drained, the fibers help the user feel dry and more comfortable since the "fibers" remain to hide the fluid. The canvas material by itself can be made from a variety of olefinic polymers, and can be made by a variety of network manufacturing process as are known in the art, the canvas can be made hydrophobic or hydrophilic by incorporating the agent correct surfactant in the resin of the polypropylene or polyolefin canvas species. The diameter of the canvas tube can be altered in the front or back to provide increased adjustment, allowing the tube to better fit the contour of the body. In addition, the canvas can be made more or less flexible, allowing the best fit to the body while retaining the elasticity in the Z direction. The technology of a stretch canvas can be incorporated into the pad to provide additional flexibility and elevation of the pad. The fibers used to hydroentangle the canvas can be selected to provide the benefits of fluid handling and can be changed to create the desired direction of fluid movement on the canvas within the core. By altering the type and / or quantity of fibers used, the material can be designed to move the fluid in a straight "down" distribution of the fluid or in a "wick effect" action in the longitudinal direction of the pad based on the structure of the transfer layer. These fibers allow the fluid to pass straight through the storage part of the core. Different types of fiber can be used, including those that have round cross sections and large denier fibers for a snug fit and greater flexibility. Also, hydrophilic fibers of "Y" cross section and capillary channel fibers (CCF) having intrafiber capillaries in their longitudinal direction on either their inner or outer surface, such as disclosed in US Pat. 5,200,248 and 5,281, 208 both from Thompson et al. These capillary channel fibers conduct fluid away from the top sheet by providing a clean, dry appearance. Any of the above fibers can be used within the canvas tube and can be hydrophobic or hydrophilic. The material for the fibers should be selected in such a way that the fibers provide elasticity, a cushioned fit even when the pad is saturated, and a rapid transport of the fluid down to the storage part of the core. An originally formed strip (transfer layer 20) is present within the canvas tube 24, which helps to move the fluid towards the core (the main storage area 18). This provides some of the capacity of the pad, and serves to absorb any fluid trapped in the fibers, which fills the absorbent canvas tube, in a preferred embodiment, this is a piece of a wet, absorbent, tissue material. with a network of pore size much smaller than the surrounding tissue. The surrounding tissue typically has a pore size network of approximately 100 microns, while the wet material has a pore size network of approximately 25 to 35 microns. The material placed in wet has smaller capillaries than the material placed by air, in such a way that the fluid tends to move from the larger capillaries to the smaller capillaries, which provides the fluid transport mechanism to the storage area. In addition, a strip will have a contact hydrophilic angle that is much smaller than that of the surrounding fiber (ie, 35 ° as compared to 89-91 °). The strip is placed inside the hydroentangled canvas tube to provide a channel for the fluid. This laminated material transports the fluid from the canvas, the introduction site, to the storage core of the pad where it can be stored. The formed strip is preferably a wet laid material known as CPN. The "NPC" as used herein is prepared as disclosed in U.S. Patent 5,334,289 to Trokhan et al. The CPN within the canvas can be arranged in such a way to collect the fluid from the canvas and the surrounding fibers, and transmit it to the storage part of the core. An additional layer of CPN, added between the core and the backsheet will prevent stacking of the absorbent article. Figures 2 (a), 2 (c) show several cross sections of Figure 1 according to several embodiments of the present invention, showing only the core 16. In particular, several portions of the transfer layer 20 are shown alternately of the core. These forms of the CPN include, but are not limited to, a rolled spike as shown in Figure 2 (a). In this embodiment, the transfer layer 20 consists of a laminated unit shank 52, which protrudes into the canvas 24 filled with the fibers 26. In the Figure 2 (b) the transfer layer is continuous. A layer of the formed film transfer layer 20 is attached to the canvas 24, which is filled with the fibers 26. An "I" laminate of the transfer layer is shown in Figure 2 (c), in FIG. wherein the CPN laminate 60 is formed as the letter I and protrudes towards part of the canvas 24 filled with the fibers 26 of the biprima core 50. This is the most preferred way for the transfer layer , since it uses the advantage of both of the two aforementioned designs. The CPN tissue material used in the tube can be replaced by a variety of materials of small pore size, flexible, absorbent and wick defect having an average pore average size of 40 to 50 microns under a pressure of 25 psi, such as melt-blown cellulose fibers, wet-laid cellulose fibers, cross-linked cellulose fibers such as those described in US Pat. No. 5,217,445 to Young et al., and others. Either of these materials may or may not be laminated with the superabsorbent material. The fibers that surround the core laminate with gelling absorbent in the tube are used to provide a cushioned fit, making the product even more flexible and adaptable to the contours of the body. The storage part of the core 18 is a laminate of AGM placed by air encapsulated on a tissue placed by air. As an alternative, a small amount of superabsorbent can be placed in the transfer layer in the AGM portion. However, this amount must be less than 10% of the total amount in the storage layer, in such a way that the swelling of the superaboster does not interfere with the transfer of the fluid. The storage layer is a material placed by air, or preferably a wet laid material having a basis weight of between 25 to 35 pounds per ream. This bends over itself and includes AGM encapsulated inside. The total capacity of this layer is between 5 to 16 grams per gram. Optionally, as shown in Figure 3, the AGM is not incorporated into the total area of the storage core 18. Since most of the fluid flow reaches the center of the layer 18, it is desirable that the fluid be maintained from a way more evenly distributed within the storage layer. By having the AGM 28 only on the periphery of the layer, more fluid will flow to the outer regions for an increased capacity of the storage layer. It is known that a thinner pad provides greater comfort. Because of the high fluid capacity, this product can remove core material without sacrificing protection. The content of the gelling absorbent material can be reduced, or the number of core layers can be reduced. Illustrative materials for use in the core include thin absorbent materials, such as 1) a 21.5 g / m2 spunbonded polypropylene nonwoven known as CELESTRA, available from Fiber eb, North America of Simpsonville, SC, which is then enhanced with the pattern described in U.S. Patent 4,781,710 issued to Megison et al .; 2) a non-woven material with thermally bonded polypropylene fibers such as the thermally bonded, carded nonwoven web of polypropylene having a basis weight of 23 grams per yard2 available from Veratec, which is then enhanced with the pattern described in FIG. U.S. Patent 4,781, 710 to Megison et al .; 3) melt blown polyethylene, 4) polypropylene, or 5) a wet laid tissue made as disclosed in U.S. Patent 5,334,289 to Trokhan et al. The (NPC) can be fixed to the back sheet of polymer. The laminated core can also be altered to improve the bending capacity, reducing the layers used, alternating the core material or ring rolling. Ring rolling involves a corrugation process described in U.S. Patent 4,107,364 to Sabee, which uses internal gear toothed rollers. The pad of the present invention allows the disadvantages as stated above; namely improved fit, improved fluid distribution and acquisition, and maximum movement of the core material during user movement. As for this latter advantage, the pad is fixed in such a way as to allow the maximum elevation of the core from the back sheet on the back of the product. This can be achieved through a unique fixation of the core, top sheet and back sheet, and it is important since the canvas tube is relatively rigid. Specifically, the top sheet is fixed, either directly or indirectly to the back sheet. A special fixation of the core to the backsheet is provided, which allows the core to uncouple from the backsheet and achieve the desired elevation and adjustment. This special fixation includes the use of folds in either the excess material of the top sheet or the back sheet, which allows the core to be removed from the back sheet while still contained within the confines of the pad. The pad is uncoupled from the backsheet either partially or completely, and at the back of the product to allow maximum lift during product use. An appropriate means for controlling decoupling, in accordance with the aspect of this invention is shown in Figure 4. The backsheet 14 is decoupled in the Z direction. The axis 48 of the Z direction is generally oriented towards the user while uses the pad 10. The excess material 30 is folded into the shape of a Z or M by bending in Z, thus allowing more material of the backsheet than the material of the top sheet 12. Since the core 16 is raised away from the adhesive facing towards the panty 38 and the posterior sheet 14 subsequently affixed, usually to the back of the product, by the movement of the user, the material of the back sheet remains unmoved and the Z-fold 30 extends from the fold lines 32 to allow movement of the core. The longitudinally oriented folds may be an extension of the topsheet 12, an extension of the backsheet 14, or a separate piece of material having an end attached to the topsheet 12 and an end attached to the backsheet 14. Preferably, 2 longitudinally oriented folds are provided, one at each longitudinal end of the pad 10. With this allowed movement of the core, the protection is not interrupted and the backsheet does not get to move from the panty, or other materials to which the fastener is fixed. absorbent article. The core can be decoupled from the backsheet by any other suitable means that allows the core to uncouple from the backsheet. The linen tube is fixed to the core and the core is decoupled, preferably fully disengaged from the backsheet as discussed above. Alternatively, some of the core material may remain attached to the backsheet while the rest of the core is lifted. These features allow the product greater lift, flexibility and natural fit in the grooves of the body. The fastener of the panty can be altered to produce the best fastening to the panty, while still allowing the necessary lifting of the core. When the pad decouples during use, the core can capture and retain any fluid that is based on high due to the reduced protection of core area by itself. In summary, the core increases and maintains the fit of the product and minimizes the contact area in order to reduce the bulge. The shape of the product and the elevation provided compensates for the reduced area of protection. Having described the invention in detail and with reference to its preferred embodiments it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.

Claims (21)

1. - An absorbent article comprising: a liquid-permeable upper sheet; a liquid impermeable back sheet attached to the top sheet; an absorbent core of a combination of material placed in air, wet-laid and superabsorbent material, said core being placed between the upper sheet and the backsheet to absorb fluid, and wherein the core includes an elongated, cylindrical, elevated portion for improve contact with the user; and a canvas material surrounding at least a portion of the elevated portion of the core.

2. The absorbent article according to claim 1, wherein the canvas contains fluid transporting fibers.

3. The absorbent article according to claim 2, wherein said canvas is hydroentangling with the fibers.

4. The absorbent article according to claim 3, wherein the fluid transporting fibers are capillary channel fibers, hydrophilic.

5. The absorbent article according to claim 1, wherein the core further includes gelling absorbent material laminated within the core.

6. The absorbent article according to claim 1, wherein the core comprises an acquisition layer, a transfer layer and a storage layer, and wherein the transfer layer lies within the canvas tube and provides a channel for the fluid from the acquisition layer to the storage layer.

7. The absorbent article according to claim 6, wherein the transfer layer is a wet formed formed strip.

8. The absorbent article according to claim 7, wherein the formed strip has a spike cross section, laminated, and lies within the linen tube.

9. The absorbent article according to claim 7, wherein the formed strip has an "I" shaped cross section and lies within the linen tube.

10. The absorbent article according to claim 7, wherein the formed strip is continuous and is connected to and lies within the linen tube.

11. The absorbent article according to claim 1, wherein the core is uncoupled from the backsheet of the back portion of the article to be lifted, such that said core is not constrained by the adjustment of a joined pantyhose and can move with the user.

12. The absorbent article according to claim 11, wherein said elevation is provided by bending in Z of the backsheet.

13. The absorbent article according to claim 11, wherein said elevation is provided by the dry folding of the upper sheet.

14. An absorbent article comprising: a top sheet permeable to liquid; a top sheet permeable to liquid; a liquid impervious back sheet, fixed to the upper sheet; an absorbent core placed between the top sheet and the back sheet, wherein the core consists of the tissue combination placed by air and wetted with superabsorbent and comprises an acquisition layer, a transfer layer and a storage layer, an elongated, elevated portion which functions as the transfer layer and lies within the elongate strip, and provides a channel for the fluid from the acquisition layer to the storage layer; means for uncoupling the core of the backsheet, in the rear portion of the article for lifting, such that the core is not restricted by the adjustment of a fixed pantyhose and can be moved by the user.

15. The absorbent article according to claim 14, wherein the formed strip has a spike cross section, laminated and lies within the elongated raised portion.

16. The absorbent article according to claim 15, wherein the formed strip has an "I" shaped cross section and lies within the raised elongated portion.

17. The absorbent article according to claim 15, wherein the formed strip is continuous and is connected to and lies within the raised elongated portion.

18. The absorbent article according to claim 14, wherein the elevation is provided by the Z-folding of the backsheet.

19. The absorbent article according to claim 14, wherein the elevation is provided by the Z-folding of the upper sheet.

20. The absorbent article according to claim 14, wherein the raised elongate portion is encapsulated with the canvas and contains the fluid transporting fibers, and wherein the canvas is hydroentangling with the fibers.

21. The absorbent article according to claim 20, wherein the fluid transporting fibers are hydrophilic capillary channel fibers.