BR102014004671A2 - cellulose-free absorbent matrix enhancement - Google Patents

Abstract

improvement in absorbent matrix without cellulose. The present embodiments of the invention relate to an improved absorbent matrix for use in a disposable absorbent article having a top facing the body and a bottom facing the garment, and such comprising a web ( 1) of polymers formed of a plurality of longitudinal wires (2) and a plurality of transverse wires (3) which form free voids (5), which are filled with particles of superabsorbent material (6), and which they form fluid absorption and retention zones such that the longitudinal wires (2) have a larger diameter than the transverse wires (3), thus forming longitudinal fluid distribution channels (4) through the lower part of the die. under the transverse wires (3).

Description

TECHNICAL FIELD OF THE INVENTION TECHNICAL FIELD OF THE INVENTION

[001] The embodiments shown of the present invention generally relate to the absorbent matrix used in disposable absorbent articles, such as baby diapers and shorts, adult diapers and shorts, women's towels, and the like, which matrix serves as a medium. fluid retention. Specifically, a thin absorbent matrix is described, consisting basically of particles of superabsorbent material and a polymer network formed by longitudinal and transverse rows defining fluid distribution channels.

BACKGROUND OF THE INVENTION

[002] Absorbent pads are currently used in disposable articles such as baby diapers, incontinent adult disposable diapers, disposable training shorts, women's towels, and pants protectors, which basically consist of a cover. top that allows fluid to pass, a liquid impermeable bottom layer, and an absorbent matrix between them. The absorbent matrix is in charge of absorbing and retaining the liquid and semi-liquid exudates of the human body (the extravasated body fluids), which penetrate through the upper cover of the article. The matrix, moreover, must be comfortable and conform to the user's body.

There are currently several proposals for thin absorbent matrices, which contain very little concentration of absorbent material fibers or even contain no absorbent material fibers, and are basically made up of particles of superabsorbent material. . For example, Mexican Patent MX 249142 protects an absorbent matrix comprised solely of superabsorbent material, and placed within a nonwoven web wrap and bonded to the web by adhesive; On the other hand, U.S. Patent 5,411,497 A discloses an absorbent matrix consisting of a first support layer, a second support layer, and an intermittent gripping means such that the matrix has zones united and unjoined areas; the unconnected zones form small pockets into which particles of superabsorbent material are placed; US Patent 5,482,761 A protects an absorbent structure with an upper cover, a lower cover, and an intermediate cover; the upper and lower layers comprise a fibrous material (nonwoven fabric) while the intermediate comprises particles of superabsorbent material; the structure furthermore has a thermoplastic material which joins the upper and lower layers forming spaced joining points which help to prevent particles of superabsorbent material from moving; U.S. Patent 6,790,798 describes an absorbent matrix composed of a non-woven fabric having a highly fibrous structure and particles of superabsorbent material contained within and about this fibrous structure; a hot-type application adhesive covers the particles of superabsorbent material to hold them in place; Lastly, US 8,466,336 discloses an absorbent, cellulose-free matrix which is formed of a substrate (nonwoven) layer, a layer of superabsorbent material particles, and a layer. thermoplastic material, generally adhesive, and such that portions of the substrate are in direct contact with the particles of superabsorbent material, and that portions of the thermoplastic material cover are in direct contact with the substrate in areas of the substrate that are not in contact with the substrate. the superabsorbent material, and portions of the thermoplastic material that are not in contact with the substrate are in direct contact with the superabsorbent material, thereby forming zones of containment of the superabsorbent material to immobilize it within the absorbent matrix. .

None of the documents cited describes an absorbent matrix comprising a polymer screen formed of longitudinal and transverse yarns that define voids to contain the particles of superabsorbent material, and flow channels that distribute the fluid reaching the matrix. so that its absorption and retention capacity is maximized. There is therefore a need for a thin matrix to guide and distribute the fluid.

MATRIX IMPROVEMENT GOALS

[005] The main object of the improvements of the present invention is to provide a user-friendly, thin absorbent matrix with high absorption capacity and fluid distribution.

Another object of the invention is that the absorbent matrix comprises a web formed by a plurality of longitudinal wires and a plurality of transverse wires.

A further object of the present improved invention is that said absorbent matrix has a first and a second support layer.

Another object of the invention is that the screen forms fluid distribution channels.

Still another object of the present invention is that the screen defines void free voids containing the superabsorbent material.

BRIEF DESCRIPTION OF DRAWINGS OR FIGURES

[010] The foregoing aspects, and many of the concomitant advantages, of these improvements of the invention are best understood by reference to the following detailed description and, taken together, to the accompanying drawings, in which: - Figure 1 is a perspective view of the mesh forming the absorbent matrix; Figure 2 shows a front and rear view of the fabric forming the absorbent matrix; Figure 3 is a perspective view of the absorbent matrix forming screen where the free voids are filled with particles of superabsorbent material; Figure 4 shows a perspective view of the fabric forming the absorbent matrix in a configuration of straight longitudinal wires and curved transverse wires; Figure 5 is a front and rear view of the fabric forming the absorbent matrix in the configuration of straight longitudinal wires and curved transverse wires; Figure 6 shows a perspective view of the web forming the absorbent matrix in the configuration of straight longitudinal wires and curved transverse wires, where the free voids are filled with particles of superabsorbent material;

Figure 7 is an additional configuration of the fabric forming the absorbent matrix. DETAILED DESCRIPTION OF INVENTION IMPROVEMENTS

[011] The present invention relates to the improvement of a cellulose-free absorbent matrix which is formed basically of a polymer screen (1) and particles of superabsorbent material (6).

[012] Figure 1 shows a perspective view of the polymer screen (1) defining the main body of the absorbent matrix of the invention. Said net (1) is made of hydrophobic material and fulfills two functions: - supporting and holding the superabsorbent material in its place; - help fluid distribution.

The absorbent matrix web (1) has a substantially rectangular shape (which can be any shape) which is formed by a plurality of longitudinal threads (2) and a plurality of transverse threads (3) where the longitudinal threads are formed. (2) have a larger diameter than the transverse wires (3) so that longitudinal distribution channels (4) are formed, allowing fluids to pass beneath the transverse wires (3).

Referring to Figure 1, it can also be seen that from the joining of longitudinal wires (2) with transverse wires (3) substantially free-form (5) shapes (any shape) can be formed with a separation between the longitudinal wires (2) of at least 5 mm, and a separation between the transverse wires (3) of at least 5 mm.

Figure 2 shows a front and rear view of the screen (1) forming the absorbent matrix; in said fig. 2 shows the largest diameter of the longitudinal wires (2) relative to the transverse wires (3); This configuration allows the formation of channels (4) that allow fluids to pass under the transverse wires (3).

Figure 3 shows a perspective view of the screen (1) forming the absorbent matrix; in said fig. 3 can be seen how the free voids (5) formed by joining the longitudinal wires (2) with the transverse wires (3) are filled with particles of superabsorbent material (6) forming absorption and retention zones (10) (ZAR), and thus, when fluid is deposited on top of the matrix, the polymer network (1) guides the fluid toward the nearest (ZAR) so that it is absorbed and retained by the supermaterial particles. -Absorbent. Once the particles of superabsorbent material of a particular (ZAR) are saturated, the fluid, instead of overflowing, passes through the longitudinal channels (4) towards the next (ZAR) and thus subsequently in order to make the most of the matrix's absorption and retention capacity.

With regard to superabsorbent material, sodium or potassium polyacrylate particles or fibers are generally used, however natural grain absorbents such as guar gum, starches and the like or mixtures of superabsorbents may also be used. -Synthetic absorbents and natural superabsorbents. This type of superabsorbent particle or fiber has a free absorption capacity of up to 80 g of synthetic urine (0.9% sodium chloride solution in water) per gram of superabsorbent material, and an absorption capacity. up to 60 g of synthetic urine per gram of superabsorbent material under pressure.

Figure 4 shows a perspective view of the polymer screen (1) in an embodiment of the present invention, formed by straight longitudinal wires (7) and transverse wires (11) having a curved zone (8) from the top. of the longitudinal wires, and a straight zone (12) forming the union between longitudinal wires. In this fabric configuration, the longitudinal wires (7) have a larger diameter than the transverse wires (11) and such that upper distribution channels (9) and lower distribution channels (4) are formed.

[019] Figure 5 shows a cross section of the fabric of fig. 4, and in this figure the upper (9) and lower (4) distribution channels can be clearly seen.

Fig. 6 shows a perspective view of the screen 1 of the configuration shown in fig. 4, and it can be seen how the free voids (5) formed by joining the longitudinal wires (7) with the transverse wires (11) are filled with particles of superabsorbent material (6), forming the absorption zones and retention (10) as in the previous configuration.

In another embodiment of the invention shown in fig. 7, the transverse wires 13 are placed over the longitudinal wires 12 such that lower distribution channels 4 are formed, as in the configuration shown in fig. 1; however, in this configuration, the transverse wires may be of the same or different diameter.

The absorbent matrix (1) of the invention may be accompanied by one or more fluid receiving and transfer caps disposed at the top of the matrix as well as by a support cap disposed at the bottom of the matrix. These take-up, transfer, and support covers can be non-woven canvas with a minimum basis weight of 9 grams / m 2, and made of polypropylene, polyester, cotton, rayon, P LA, P Η A, bicomponent fiber. , or mixtures of said fibers; the characteristics of the nonwoven fabric to be used will be determined according to the use that will be given to the fabric, for example preferably the backing cover is hydrophobic while the receiving or transfer cover or covers are hydrophilic, to allow liquids to pass through. Instead of using receiving, transfer, and support covers, a single overlapping cover overlying the top of the screen (1) may be used, which may have one or more hydrophobic zones to be placed (and the ears matrix longitudinal sections) at the bottom of the web, and one or more hydrophilic zones which will be placed at the top of the absorbent matrix; In addition to this enclosure, other receiving and / or transfer covers may be used over the top of the die.

Although the invention has been described by reference to its preferred embodiments, the scope of the invention comprises any type of change or modification that may be apparent to one of ordinary skill in the art.

Claims

Claims (12)

1. Improved absorbent matrix for use in a disposable absorbent article with an upper body facing part and a lower face facing garment characterized by the fact that it comprises a polymer screen (1) formed of a plurality of longitudinal yarns (2) and with a plurality of transverse yarns (3) which form free voids (5), which are filled with particles of superabsorbent material (6), and which form absorption and retention zones such that the longitudinal wires (2) have a larger diameter than the transverse wires (3), thus forming longitudinal fluid distribution channels (4) through the underside of the matrix, below the wires ( 3) transverse. Improved absorbent matrix for use in a disposable absorbent article having an upper and lower part, characterized in that it comprises a polymer web (1) formed with a plurality of straight longitudinal threads (7) and a plurality of transverse wires (8), with a curved zone (10) above the longitudinal wires, and a straight zone (11) which, between the longitudinal wires, form free voids (5) therebetween which are filled with particles of superabsorbent material (6), and forming fluid absorption and retention zones, such that the straight longitudinal wires have a larger diameter than the curved transverse wires, thus forming upper distribution channels (9). ) and lower distribution channels (4). Improved absorbent matrix for use in a disposable absorbent article having an upper and lower part, characterized in that it comprises a polymer web (1) formed with a plurality of longitudinal threads (13) and a plurality of transverse yarns (14) placed over the longitudinal yarns, which form free voids (5), which are filled with particles of superabsorbent material (6), and which form fluid absorption and retention zones, such that the longitudinal wires (13) have the same diameter as the transverse wires (14), thus forming longitudinal fluid distribution channels (4) through the lower part of the die below the transverse wires (14). Improved absorbent matrix according to any one of claims 1, 2 and 3, characterized in that the matrix is covered by a fluid receiving cover. Improved cellulose-free absorbent matrix according to any one of claims 1, 2 and 3, characterized in that the matrix has a support layer disposed on the underside thereof. Improved absorbent matrix according to any one of claims 1, 2 and 3, characterized in that the absorbent matrix is covered by a surrounding layer. Improved cellulose-free absorbent matrix according to any one of claims 1, 2 and 3, characterized in that the matrix has a receiving cover and a transfer cover placed on top of it. Improved absorbent matrix according to any one of claims 4 to 7, characterized in that the receiving cover, the transfer cover, the support cover or the surrounding cover is a non-woven fabric of a basic weight. of at least 5 grams / m 2. Improved absorbent matrix according to any one of claims 4 to 8, characterized in that the receiving cover, transfer cover, support cover, or surrounding cover are made of polypropylene, polyester fibers, cotton, rayon, PLA, P Η A, bicomponent fibers, fiber mixtures, or any other suitable fiber for this purpose. Improved absorbent matrix according to any of claims 4, 5, 7, 8 and 9, characterized in that the receiving layer and the fluid transfer layer are hydrophilic, and the support layer is hydrophobic. Improved absorbent matrix according to claim 6, characterized in that the surrounding cap has one or more hydrophilic zones which will be positioned at the top of the matrix and one or more hydrophobic zones which will be positioned at the side and bottom of the matrix. matrix. Improved absorbent matrix according to any one of claims 1, 2 and 3, characterized in that the free voids (5) have a longitudinal wire separation of at least 5 mm, and a transverse wire separation of at least 5 mm. at least 5 mm.