MX2013014296A

MX2013014296A - Improvements in cellulose less absorbent matrix.

Info

Publication number: MX2013014296A
Application number: MX2013014296A
Authority: MX
Inventors: Lucía Del Carmen Sánchez Fernández; Raúl Gonzaléz Martínez; Carlos Canales Espinosa De Los Monteros
Original assignee: Grupo P I Mabe Sa De C V
Priority date: 2013-12-05
Filing date: 2013-12-05
Publication date: 2015-06-05
Also published as: BR102014004671A2; MX353253B; WO2015083122A1

Abstract

Described is an absorbent matrix used in a disposable absorbent item, which has an upper portion facing the body and a lower portion facing the garment surface, comprising a polymeric network (1) formed by a plurality of longitudinal threads (2) and a plurality of transversal threads (3) that form free hollows (5) therebetween, which are covered by particles of a super absorbent material (6) that form zones of absorption and liquid retention, the longitudinal threads (2) being higher in diameter than the transversal threads (3), thus forming longitudinal channels for distributing the fluid (4) by the lower portion of the matrix, under the transversal threads (3).

Description

IMPROVEMENTS TO ABSORBENT MATRIX WITHOUT CELLULOSE FIELD OF XA INVENTION The illustrated embodiments of the present invention is generally related to the absorbent matrix used in disposable absorbent articles such as diapers and baby pants, diapers and briefs for adults, sanitary towels, etc., which serves as a fluid retention. Specifically, a thin absorbent matrix consisting basically of particles of superabsorbent material and a polymer network formed by longitudinal and transverse rows defining fluid distribution channels is described.

BACKGROUND OF THE INVENTION Currently absorbent matrices are used in disposable articles, such as baby diapers, disposable incontinence diapers, disposable training pants, feminine towels and protective panty, which basically consist of a top layer that allows the passage of fluid, a layer lower impervious to liquids and an absorbent matrix between both. The absorbent matrix is responsible for absorbing and retaining the liquid and semi-liquid exudates of the human body that penetrate through the top layer of the article. The matrix must also be comfortable and conform to the body of the user.

There are currently several proposals for thin absorbent matrices, which contain very little concentration of fibers of absorbent material or even that do not contain fibers of material absorbent, are basically constituted by particles of superabsorbent material. For example, Mexican patent MX 249,142 protects an absorbent matrix constituted solely by superabsorbent material placed inside a wrap layer of non-woven fabric and joined thereto by means of adhesive; on the other hand, the US patent US 5411497A describes an absorbent matrix constituted by a first support layer, a second support layer and a binding means that intermittently secures them, so that the matrix has joined areas and unattached areas; the unattached areas form small pockets where particles of superabsorbent material are placed; the patent US5482761A protects an absorbent structure with an upper layer, a lower layer and an intermediate layer; the upper and lower layers comprise a fibrous material (non-woven fabric), while the intermediate layer comprises particles of superabsorbent material; the structure also has a thermoplastic material that joins the upper and lower layers forming spaced joining points that help the particles of superabsorbent material do not move; Patent US6790798 discloses an absorbent matrix composed of a nonwoven fabric with a highly fibrous structure and particles of superabsorbent material contained inside, and this fibrous structure, an adhesive hotmelt covers the particles of superabsorbent material to keep them in place; finally, US Pat. No. 8466336 discloses an absorbent matrix without cellulose fibers, formed by a substrate layer (non-woven fabric), a layer of particles of material superabsorbent and a layer of thermoplastic material, generally adhesive, such that portions of the substrate are in direct contact with the particles of superabsorbent material; portions of the layer of thermoplastic material are in direct contact with the substrate in areas thereof that are not in contact with the superabsorbent material and portions of the thermoplastic material that are not in contact with the substrate, are in direct contact with the material superabsorbent, thus forming containment zones of the superabsorbent material to immobilize it within the absorbent matrix.

None of the cited documents discloses an absorbent matrix comprising a polymeric network formed by longitudinal and transverse filaments defining voids for containing the particles of superabsorbent material, and flow channels which distribute the fluid reaches the matrix, so that the capacity of absorption and retention of the same take advantage to the maximum. There is, therefore, a need for a thin matrix to guide and distribute the fluid.

OBJECTIVES The main objective of the present invention is: to provide a thin absorbent matrix, comfortable for the user, with high capacity of absorption and distribution of fluids.

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

A further objective of the present invention is that said absorbent matrix, presents a first and second support layer.

Another objective of the invention is for the network to form fluid distribution channels.

Still another objective of the present invention is that the network defines free holes of yarns containing the superabsorbent material.

BRIEF DESCRIPTION OF THE DRAWINGS OR FIGURES The above aspects and many of the concomitant advantages to this invention will be better understood when the following detailed description is consulted and considered in conjunction with the accompanying drawings, in which: Figure 1 is a perspective view of the network forming the absorbent matrix.

Figure 2 shows a front and back view of the network forming the absorbent matrix.

Figure 3 is a perspective view of the network forming the absorbent matrix, wherein the free voids are covered with particles of superabsorbent material.

Figure 4 shows a perspective view of the network forming the absorbent matrix in a straight longitudinal thread and curved transverse yarn mode.

Figure 5 is a front and rear view of the net forming the absorbent matrix in the straight longitudinal yarn and curved transverse yarn mode.

Figure 6 shows a perspective view of the network forming the absorbent matrix in the straight longitudinal thread and curved transverse yarn mode, where the free holes are covered with particles of superabsorbent material.

Figure 7 is an additional embodiment of the network that forms the absorbent matrix DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the improvement to an absorbent matrix without cellulose, which is basically formed by a polymer network (1) and particles of superabsorbent material (6).

Figure 1 shows a perspective view of the polymer network (1), which defines the main body of the absorbent matrix of the invention. Said net (1), is made of hydrophobic material and fulfills two functions: • Hold and keep the superabsorbent material in place.

Help the distribution of the fluid.

The net (1) of the absorbent matrix has a substantially rectangular shape (it can be of any shape), which is formed by a plurality of longitudinal threads (2) and a plurality of transverse threads (3); wherein the longitudinal threads (2), have a larger diameter than the transverse threads (3) so that longitudinal distribution channels (4) are formed, which allow the passage of fluids below the transverse threads (3).

With respect to Figure 1, we can also see that from the union of longitudinal threads (2) and transverse threads (3), free holes (5) are formed substantially square (can be any way) with a separation between threads longitudinal (2), of at least 5 mm and a separation between transverse threads (3) of at least 5 mm.

Figure 2 shows a front and back view of the network (1) that forms the absorbent matrix; in said figure 2, we can see the greater diameter of the longitudinal threads (2) with respect to the transverse threads (3); this configuration allows the formation of channels (4) that allow the passage of fluids below the transverse threads (3).

Figure 3 shows a perspective view of the network (1) that forms the absorbent matrix; in said figure (3), we can see how the free holes (5) formed by the union of the longitudinal threads (2) and transverse threads (3), are covered by particles of superabsorbent material (6), forming zones of absorption and retention of fluid (ZAR) (10), thus, when the fluid is deposited on the upper part of the matrix; the polymeric network (1) guides the fluid to the nearest ZAR to be absorbed and retained by the particles of superabsorbent material. Once the particles of superabsorbent material of a particular ZAR are saturated, the fluid, instead of overflowing, passes through the longitudinal channels (4) to the next ZAR and so on, so that the maximum use is made of the capacity of absorption and retention of the matrix.

With respect to the superabsorbent material, sodium or potassium polyacrylate particles or fibers are generally used, however, natural granule absorbers such as guar gum, starches, etc., or mixtures of synthetic superabsorbents and natural superabsorbents can also be used. This type of superabsorbent particles or fibers have a free absorption capacity of up to 80 g of synthetic urine (0.9% sodium chloride solution in water) / g of superabsorbent material and an absorption capacity under pressure of up to 60 g of synthetic urine / gr of superabsorbent material.

Figure 4 shows a perspective view of the polymer network (1) in an embodiment of the present invention, formed by straight longitudinal threads (7) and transverse threads (11) having a curved area (8) at the upper part of the longitudinal threads, and a straight zone (12), which forms the union between longitudinal threads. In this embodiment of the network (1), the longitudinal threads (7) have a larger diameter than the transverse threads (11), such that upper distribution channels (9) and lower distribution channels (4) are formed. 5 Figure 5 shows ün. cross section of the network of figure 4, in this figure you can clearly see the upper (9) and lower (4) distribution channels.

Figure 6 shows, a perspective view of the net (1) of the embodiment shown in figure 4, can be seen as the free holes (5) formed by joining the longitudinal wires (7) with the transverse threads (11), are covered by particles of a superabsorbent material (6), forming the absorption and retention zones (10) as in the previous embodiment.

In another embodiment of the invention shown in Figure 7, the transverse threads (13) are placed on the longitudinal threads (12), such that lower distribution channels (4) are formed as in the embodiment shown in Figure 1, however, in this embodiment the transverse threads can be of the same or different diameter.

The absorbent matrix (1) of the invention can be accompanied by one or more layers of reception and transfer of fluids placed on top of it, as well as a support layer placed by the bottom of the matrix. These 25 layers of reception, transfer and support, can be fabric woven with a minimum basis weight of 9 g / m2 and made of polypropylene fiber, polyester, rayon, cotton, PLA, RHD, bicomponent fibers or mixtures of the above; the characteristics of the nonwoven fabric to be used will be determined according to the use to which it will be given, for example, preferably the support layer is hydrophobic, while the receiving and transfer layer (s) are hydrophilic to allow the passage of liquids. Instead of using reception, transfer and support layers, a single envelope layer can be used that is superimposed by the upper part of the network (1), which can have one or more hydrophobic zones that will be placed on the longitudinal edges of the network. the matrix and in the lower part of it,) and one or more hydrophilic zones that will be placed by the upper part of the absorbent matrix; in addition to this envelope layer, other reception and / or transfer layers may be used on top of it.

Although the invention has been described in terms of its preferred embodiments, the scope thereof includes any type of change or modification thereto that may be apparent to a person skilled in the art.

Claims

1. - An absorbent matrix for use in a disposable absorbent article with an upper part facing the body and a lower part facing the garment, characterized in that it comprises a polymeric network (1) formed by a plurality of longitudinal threads (2) and a plurality of transverse threads (3) forming between them, free holes (5) that are covered by particles of superabsorbent material (6) forming zones of absorption and retention of fluids, such that the longitudinal threads (2) are of a diameter greater than the transverse threads (3), forming longitudinal channels of fluid distribution (4) through the lower part of the matrix, below the transverse threads (3).

2. - An absorbent matrix for use in a disposable absorbent article with an upper part and a lower part, characterized in that it comprises a polymeric network (1) formed by a plurality of straight longitudinal strands (7) and a plurality of transverse threads (8) , with a curved zone (10) above the longitudinal threads, and a straight zone (11) that between the longitudinal threads, such that they form between them, free holes (5) that are covered by particles of superabsorbent material (6) forming zones of absorption and retention of fluids, such that the straight longitudinal threads have a larger diameter than the curved transverse threads, thus forming upper distribution channels (9) and lower distribution channels (4).

3. - An absorbent matrix for use in a disposable absorbent article with an upper part and a lower part, characterized in that it comprises a polymeric network (1) formed by a plurality of longitudinal threads (13) and a plurality of transverse threads (14) placed on the longitudinal threads, which form between them, free holes (5) that are covered by particles of superabsorbent material (6) forming zones of absorption and retention of fluids, such that the longitudinal threads (13) are of the same diameter as the threads transverse (14), forming longitudinal channels of fluid distribution (4) through the lower part of the matrix, below the transverse threads (14).

4. - An absorbent matrix according to claims 1, 2 and 3, characterized in that the matrix is covered by a fluid receiving layer.

5. - An absorbent matrix without cellulose according to claims 1, 2 and 3, characterized in that; the matrix has a support layer placed by the lower part thereof.

6. - An absorbent matrix according to claims 1, 2 and 3, characterized in that; The absorbent matrix is covered by a wrapping layer.

7. - An absorbent matrix without cellulose according to claims 1, 2 and 3, characterized in that; the matrix has a reception layer and a transfer layer placed on top of it.

8. - An absorbent matrix according to any of claims 4 to 7, characterized in that; the receiving layer, the transfer layer, the support layer or the wrapping layer, is a non-woven fabric with a basis weight of at least 5 g / m2.

9. - An absorbent matrix according to claims 4 to 8, characterized in that; the receiving layer, the transfer layer, the support layer or the wrapping layer are made of polypropylene, polyester, cotton, rayon, PLA, PHA fibers, bicomponent fibers, mixtures of the above or any other type of fiber suitable for this end.

10. - An 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.

11. - An absorbent matrix according to claim 6, characterized in that the wrapping layer has one or more hydrophilic zones that will be placed in the upper part of the matrix and one or more hydrophobic zones that will be placed by the lateral and lower parts of the matrix .

12. - An absorbent matrix according to claims 1, 2 and 3, characterized in that; the free holes (5), have a separation between longitudinal threads of at least 5 m and a separation between transverse threads of at least 5 mm.