MXPA00004146A - Disposable diaper with improved system of fluids retention by means of impermeable interior barriers. - Google Patents

Abstract

The present invention discloses disposable diapers for infants and/or adults comprising: a posterior impermeable covering, an upper permeable covering, an absorbent core placed between both of them, a pair of lateral ends adjacent to the absorbent core, an elasticized zone at the legs region situated in each of the lateral ends, elasticized posterior waist zone and elasticized frontal waist zone, fastening means disposed at the rear waist region and a bracing mean placed at the frontal waist part over the exterior covering; a pair of lateral barriers formed by an upper end and a lower end; said lower end longitudinally adhered over the absorbent core covering a part of its material, so that any leakage is stopped by the barrier and absorbed by the absorbent core; the upper end forms a fold in which there are placed elastic elements that maintain the barrier upright.

Description

BACKGROUND OF THE INVENTION Disposable diapers were conceived to serve as a means of containing body exudates, i.e. fecal matter and urine, in such a way as to prevent them from dirtying the clothes of the users or objects or other garments that are around them. The disposable diaper was born from the need to provide an article of this type that was more practical to use than previously existing diapers, which consisted of a piece of cloth secured to the user by fastening systems such as pins, hooks or safety locks. These diapers, once soiled, were removed from the user's body and washed to be reused again. Reusable diapers have several disadvantages in their use being one of them the poor ability to retain and contain the secretions they receive. In addition, they do not allow the flexibility of being discarded once they get dirty, which forces the people who serve diaper users to store them under these conditions until they are washed. This can lead to a hygiene problem because it generates an unhealthy environment and possible generator of infections.

A typical disposable diaper model is that described in US Patent 3860003 issued to Kenneth Barclay Buell in January 1975. It describes a diaper comprising a top cover permeable to the passage of liquids, a waterproof back cover, an absorbent core positioned in the middle of both covers and a pair of elasticized leg regions extending along each of the edges of the diaper. This design aims to improve the anatomical adjustment of the diaper and at the same time increase the capacity for containing secretions by means of a seal formed by the contractile action of the elasticized regions around the user's thighs. Although a substantial improvement is achieved with this model, even the rate of runoff and leakage of fecal matter and urine remains high since a large part of this material is in free movement within the diaper and, with the activity of the user, it is possible to escape through the spaces that remain between the disposable diaper and the crotch region. An important improvement to the disposable diapers is described in the North American patent 4704116 granted to Kenneth Enloe, the concept of lateral barriers placed on the surface of the diaper in a position perpendicular to the plane thereof is introduced. This diaper - consisting of a permeable top cover, a waterproof back cover, an absorbent core placed between the two, an elasticized leg region placed parallel to the diaper plane and on each of the longitudinal edges thereof and a pair of side barriers permeable to the fluid placed adjacent to the parallel regions perpendicular to the plane of the diaper - it was designed with the objective of keeping the solid secretions inside, preventing them from "floating" or moving freely on the surface of the upper cover; Such a way that said secretions do not easily reach the edges of the diaper and leak through the spaces between the thighs and the crotch of the wearer and the elastified leg region. The design described in this patent proposes a means against leakage of solid secretions but not against the escape of liquids such as urine and liquid fecal matter which can pass through the material from which the barrier is formed, being able to reach the diaper edge. As a solution to the problem present in the previous design, the US patent 4695278 granted to Michael I. Lawson, proposes the use of a waterproof material for the manufacture of the lateral barriers that, together, with the elasticized leg region form a restriction dual to the leakage of secretions. The disposable diaper described in the patent consists of a permeable top cover, a waterproof back cover, an absorbent core placed between both covers, an elasticized leg region placed on each of the longitudinal ends of the diaper, a pair of lateral barriers perpendicular to the diaper plane and placed adjacent to the elasticized leg region in the space between said region and the edge of the absorbent core. When the secretions are received on the upper cover of the disposable diaper, they tend to move towards the sides of the same, finding in their way the lateral barrier that keeps them in the first instance confined inside the area of reception of exudates, since the Movement of said secretions would have to be against the direction of the force of gravity. Subsequently and for the case in which the secretions, solid and liquid, pass beyond the barrier, the elasticized leg region forms a seal around the thighs of the user that prevents leakage of the secreted material. The system mentioned in the previous patent has proven to be highly effective in decreasing secretion runoff rates due to the work done by both barriers. However, when the barriers are placed in the space between the edge of the core and the elasticized leg region, there is a possibility that the liquids absorbed by the core of the diaper are transmitted, by capillarity, below the barrier to the edges. of the diaper and filter through the spaces between the user's thighs. This filtration is due to the fact that in the design there is an overlap or overlap between the materials that form the lateral barrier, hydrophobic in nature, and the one that forms the upper barrier, hydrophilic in nature. The overlap causes that the liquids can pass through the hydrophobic barrier because when there is contact between two humid zones, the surface tension of the materials is changed, increasing the contact angle between the surface of the liquid and the surface of the barrier. Another phenomenon that can occur is the possible transmission of the substance in charge of providing hydrophilicity to the upper cover, called a surfactant, towards the hydrophobic material of the lateral barrier. A proposal for the correction of said problem is described in the US patent 4795454 granted to Jerry Layne Dragoo. The diaper comprises a liquid-permeable top cover, a waterproof back cover, an absorbent core located in the middle of the two, an elasticized leg region placed on each longitudinal edge of the diaper, a pair of lateral barriers placed adjacent to each elastified leg region between the edge of the absorbent core and said region; each barrier also consists of a distant edge away from the surface formed by the diaper plane, a nearby edge joined to the diaper by means of a seal line all along said edge and which also forms a strip resistant to the passage of liquids, preventing that seep below the barriers. In addition, the permeable or hydrophilic top cover has such an amplitude that it extends and terminates in the area where the barrier is fixed to the rest of the diaper structure, i.e., the proximal edge. With this, the permeable material is prevented from overlapping or overlapping with the hydrophobic material of the barrier, reducing the risk that, by capillarity, the liquid is transmitted below the barriers and extends to the edges of the diaper, where It would cause a leakage of secretions. This system has represented a good way to reduce the incidence of leaks in disposable diapers. Despite the success of this design, the placement of the barriers in the space between the edge of the absorbent core and the elasticized region of the legs causes the urine, mainly, to accumulate during the time it takes to reach an area in that the material of the nucleus reaches it and proceeds to absorb it. This accumulation of urine, due to the barrier effect of the barrier, causes the user's skin to be in prolonged contact with it, which can lead to irritation or pinking. Another design of more barriers against leakage is described in the North American patent 5643243 granted to Walter Klemp. The patent discloses a disposable diaper in which the secretion containment system is formed solely by the side barriers placed adjacent to the absorbent core without the use of the elasticized leg regions. This design fails in the fact that in the absence of the anatomical adjustment provided by the leg elastics, the exudates that manage to pass beyond the barrier will be more likely to elope from the diaper. The inventorial record H1630 issued in the United States in January 1997 in the name of Donald C. Roe et al. Describes a design with a double system of lateral barriers, placing a pair of them parallel with respect to each other and being placed on the surface of the absorbent core and supported, or maintained, in its position solely by elastic elements without being adhered to the core or to any other underlying element of the disposable diaper. These interior barriers are permeable characteristic barriers and designed for the containment of solid secretions only. US Patent 4808177 issued to Desmarais describes another dual system of side barriers, wherein the inner pair is fixed at the ends of the waist area of the diaper and is held without touching the absorbent core by elastic elements. Likewise, this system of "floating" internal barriers is designed for the retention mainly of the solid fecal material secreted by the users. Mexican patent 185778 issued to Maximino Bear Sanz describes a disposable diaper consisting of an impermeable outer layer, a permeable inner layer and a layer of absorbent material located therebetween, an elastified leg region on each longitudinal edge of the diaper; It also has a pair of impermeable side barriers placed on the edge of the absorbent core. This system of barriers is formed from a unitary piece independent of the rest of the diaper structure already formed and is placed on the upper cover which extends to the edges thereof, which represents a disadvantage, since liquids can get to filter by capillarity before the absorbent core reaches to retain them. As can be seen, the current designs of disposable diapers have some deficiencies that reduce their capacity for the containment of waste secreted by users. Due to the above, an object of the present invention is to provide an absorbent article that is capable of accepting and containing the liquid and solid waste of the body without having run-off.

Another object of the present invention is to provide an absorbent article that is comfortable while resisting run-off. Another object of the present invention is to provide an absorbent article with improved containment characteristics by the use of efficiently placed inner side barriers. Other objects of the present invention will be clearly appreciated by those skilled in the art and in part will be pointed out later in the present description.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is the top view of a typical disposable diaper where it is shown the area that is in contact with the user's skin.

Figure 2 is a cross-section along line 2-2 of the disposable diaper showing the preferred configuration in the present invention BRIEF DESCRIPTION OF THE INVENTION The disposable diaper of the present invention has an improved system of secretion retention that reduces the free space for the movement thereof which allows the liquids to be in contact with the absorbent core for a longer period of time and to be acquired by the same. before they have the possibility of, by any movement of the user, filtering and reaching the edges of the disposable diaper. The disposable diaper is constituted by a waterproof back cover whose surface is removed from being in contact with the wearer's body, more specifically, it is placed towards the outside to be in contact with the garments, a permeable upper cover whose surface is in contact with the user's skin and is soft and comfortable enough to provide comfort and avoid irritation caused by friction; an absorbent core placed between both covers; a sheet of thin paper placed between the bottom of the absorbent core and the back cover; a pair of lateral ends adjacent to the absorbent core; an elastified zone in the region of the legs located at each of the lateral ends; a back waist zone and an elasticized waistband area; a pair of elasticized areas of crotch barriers, or lateral barriers, placed longitudinally between the rear and front waist areas, which are arranged on the absorbent core which allows it to have more time to exercise its function and fecal matter have a smaller space to move freely on the upper deck. A landing or grip system for the closure system, placed in the front waist region on the outer side of the rear cover; such closure system can be constructed by plasticized tapes covered on one side with pressure sensitive adhesive. The manner in which said improvement is carried out will fall within the detailed description of the present invention.

DETAILED DESCRIPTION OF THE INVENTION With reference to Figure 1, the disposable diaper 10 is composed of a longitudinal centerline 1-1, a transverse centerline 2-2, a pair of longitudinal edges 12, a pair of crotch regions 14, a waist front region 16, a rear waist region 18, a liquid-permeable top cover 20 which functions as a receiver for exudates, a liquid-impermeable back cover 22, an absorbent core 24 positioned between the top cover and the rear cover, a pair of side barriers 26, a pair of elastified leg zones 28, a pair of fastening means 30 positioned at each end of the waist regions, a pair of elastified pieces 32 positioned in each waist region. In addition, the disposable diaper 10 may or may not carry a thin sheet of paper 34 placed on the back face of the absorbent core 24. It also has elastic elements and attachment means such as hot melt adhesives or any other known in the art. These elements are not shown in Figure 1, The longitudinal edges 12 together with the waist regions 16 and 18 and the crotch zones 28, form the periphery of the disposable diaper 10. The top cover 20, which is seen in Figure 1, is soft and non-irritating to the wearer's skin. It is permeable to the liquid which allows this passage to pass through it to the absorbent core 24. The functions of the upper cover 20 include keeping the user's body isolated from the materials constituting the absorbent core 24, preventing the return of moisture from the nucleus and be the receptor area of exudates secreted by the user. The top cover 20 may be made from a wide variety of materials well known in the art such as porous foams, apertured plastic films, woven or nonwoven webs of natural fibers, synthetic fibers or a combination of synthetic and natural fibers. The size of the top cover depends on the size of the absorbent core 24 and the overall configuration of the disposable diaper. By way of example, an upper cover with a length between 32 and 55 cm and a width between 1 1 and 19 cm can be mentioned. An example of preferred material for the manufacture of the top cover 20 is a piece of nonwoven material made of mechanically bonded polypropylene fibers. Some physical characteristics of this material are the base weight of around 14 to 19 g / square meter, with a tensile strength in machine direction (longitudinal with respect to the material) between 1600 and 1900 g / in and in transverse direction between 900 and 1300 g / in. Likewise, it presents an elongation in the machine direction between 40 and 60% and transversally between 50 and 60%. This top cover of 7 polypropylene must have a surfactant treatment that allows it to acquire a hydrophilic characteristic, that is, it allows the passage of liquids through it. Said treatment can be carried out totally or partially depending on the needs of the design. In addition, the top cover can also carry the application of additives that help the health of the user's skin such as creams based on oils or natural products such as Aloe Vera or Aloe Vera.

The back cover 22 is impermeable to fluids and is mainly made of a thin and flexible plastic film whose main function is to prevent the secretions absorbed by the core 24 from coming out of the disposable diaper 10 at the rear of the absorbent core.

The back cover 22 is positioned adjacent the back surface of the absorbent core 24, which is directed towards the wearer's garments. It is adhered by, for example, a continuous uniform layer of hot melt adhesive, a layer with a certain pattern (spirals, solid lines, dots, etc.). Various adhesives with the required characteristics exist in the art. The back cover can be made of any flexible plastic material, impermeable to the passage of fluids, resistant and able to effectively contain the exudates. A typical material used for the construction of the back cover is a polyethylene film that has a base weight between 20 and 26 g / square meter with a tensile strength under load between 1300 and 2000 g in machine direction and 1050 a 1700 g in the transverse direction. Other materials that can be used for the manufacture of the back cover 22 comprise polymer films of woven or nonwoven material of polypropylene or polyethylene, as well as the use of thermoplastic materials. The back cover 22 can have breathability characteristics, a term that refers to the ability of a material to allow the passage of air through them. Also, the back cover can be made of a laminated material that gives it an appearance similar to ordinary garments. The size of the back cover is determined by the design size of the disposable diaper. Usually, the back cover extends - figure 2 - to form the longitudinal edges of the disposable diaper as well as the waist regions 16 and 18 and the crotch regions 14 which together form the periphery of the diaper 10. The absorbent core 24 is placed between the upper cover 20 and the rear cover 22, as shown in figure 2. It can be made of any absorbent member, generally compact, comfortable and non-irritating to the user's skin and with the ability to capture and retain liquids that reach him, such as urine and liquid stool. The absorbent core 24 can be manufactured in a wide variety of sizes and shapes (rectangular, hourglass-shaped, asymmetric, T-shaped, I-shaped, etc.) and a wide variety of liquid-absorbing materials commonly used in the design of disposable diapers and other absorbent articles such as crushed wood pulp, cellulose pulp, etc. Other materials usually employed include hardened, modified or chemically entangled cellulosic fibers, fabric envelopes, fabric laminar units, absorbent foams, superabsorbent gel materials or any other material or combination of materials well known in the current art. The construction and configuration of the absorbent core 24 can vary (design with hydrophilic gradient, superabsorbent gradient, low density zones, etc.). In addition, the size and capacity of the core 24 can also be varied to meet the different sizes of the user.

The absorbent core 24 may further comprise a sheet of thin paper 34 which serves as reinforcement by providing greater resistance to deformation at the time of being wet. Said sheet of thin paper can be placed in different configurations. It may be wrapped around the core or placed on top of it. It can also be arranged on the back of the absorbent core. A typical absorbent core design consists of a homogeneous mixture of natural cellulose fibers and granules of superabsorbent material (SAP) made of sodium polyacrylate. The main function of the superabsorbent is to absorb and retain the fluids to prevent them from escaping the nucleus. The mixture can be in different proportions of cellulose / SAP and, by compaction, a certain density is provided. The absorbent core can also carry a top layer of liquid distribution made of polypropylene fibers that facilitate the movement of the liquids by rapidly moving them towards the various regions of the absorbent core. The elasticized leg region 28 is formed by the extension of the back cover 22 in the crotch region 14 and a set of elastics disposed over said extension. The function of the elasticized region of leg 28 is to provide a seal that prevents leakage of secretions in the area of the user's thighs. The elastics are placed in their extended, ie tensioned, form and adhered by any means of attachment known in the art. Upon returning to its natural state without tension, the elastic causes the material of the back cover to contract and fit anatomically around the user's thighs. As this material is impermeable, fluids are not able to penetrate this barrier.

The lateral barrier 26 is formed by an upper end 36, a lower end 38, a barrier extension 40 and an elastic element 42 placed inside a barrier fold 44 which serves to allow the anatomical adjustment of the barrier to the body of the body. user. See figure 2. Side barrier 26 can be manufactured from a wide variety of materials such as elastomeric films, non-woven polypropylene material, laminations of materials, etc. A typical material used for forming the side barrier is a piece of nonwoven material of hydrophobic polypropylene fibers, ie, resistant to the passage of liquids. As seen in Figure 1, the side barrier 26 is disposed longitudinally on the disposable diaper 10. In Figure 2 it can be seen structurally how the side barriers 26 are assembled with the remaining elements to form the containment system .

The preferred way of placing the barriers is to arrange them on the absorbent core in such a way that a channel for receiving exudates on the core of at least 10 cm in width is formed between the two barriers. This will allow the exudates, especially liquids, secreted by the user to remain a longer time in contact with the absorbent core in such a way that it can perform its function efficiently avoiding run-off. Figure 2 shows the preferred configuration in the present invention in which the lateral barrier 26 is placed on the absorbent core 24 at a distance of at least 1 cm inwards from the longitudinal edge of the absorbent core to allow a separation between barriers of, at least, 10 cm. It is evident that said separation between barriers can be modified to fit the needs of the user. The term "inward" refers to the direction toward the central line 1-l of Figure 1. The lateral barrier 26 is to be formed in addition to a upper end 36, a lower end 38 and a barrier extension 40 formed of the same material from which the side barrier 26 is manufactured. At the end upper 36 a fold is formed in which one or more elastic elements 42 are placed which serve to keep the lateral barrier 26 upright. The upper cover 20 may or may not extend below the lateral barrier 26. This mode will allow the lateral barrier 26 keep the liquids mainly in contact with the absorbent core 24 for a longer period of time so that the portion that has not been immediately absorbed is once the core has already absorbed most of the initial discharge, preventing runoff from liquid through the capillarity barrier. 10

Claims (3)

1. CLAIMS 1. Disposable diaper to be worn by infants and / or adults that comprises; a waterproof back cover, a permeable top cover, an absorbent core positioned therebetween, a pair of side ends adjacent to the absorbent core, an elastified zone in the region of the legs located at each of the lateral ends, a rear waist zone and an elasticized front waist area, fastening means disposed in the rear waist region and a gripping means positioned in the front waist portion on the outer cover; a pair of side barriers formed by an upper end and a lower end; said lower end adhered longitudinally on the absorbent core covering a part of the material thereof, such that any runoff is contained by the barrier and absorbed by the absorbent core; the upper end forms a fold in which elastic elements are placed that keep the barrier upright.
2. 2. The disposable diaper of claim 1 characterized in that the material of the side barriers extends to the longitudinal edges of the disposable diaper, forming a delay means for the flow of liquids from the absorbent core.
3. 3. The disposable diaper of claim 1 characterized in that the permeable top cover does not overlap outside the core with the material from which the side barrier is made thus preventing the liquids from being filtered by capillarity below it. eleven