MXPA02000072A

MXPA02000072A - Disposable absorbent article with improved integrity.

Info

Publication number: MXPA02000072A
Authority: MX
Inventors: Gonzalez Martinez Raul
Original assignee: Grupo P I Mabe Sa De C V
Priority date: 2001-12-19
Filing date: 2001-12-19
Publication date: 2005-07-25
Also published as: BR0205575A; ES2200715B1; ES2200715A1; BR0205575B1

Abstract

The present invention refers to an absorbent matrix having an L total length, a front portion, a rear portion and a crotch portion having an A width. The matrix is mainly formed by fibers of an absorbent material, having or not a superabsorbent material, which includes an integrity network therein where the fibers are looped and joined together, thereby forming an attachment between the fibers and the network so as to ensure the integrity of the same even when the matrix is saturated or upon an abrupt movement of the user.

Description

DISPOSABLE ABSORBENT ARTICLE WITH IMPROVED INTEGRITY BACKGROUND OF THE INVENTION Disposable absorbent articles, such as disposable diapers for babies, disposable incontinence pads, trainers, and feminine pads and other catamenial devices, generally consist of a single layer upper that allows the passage of the liquid, a waterproof lower shell, and an absorbent matrix placed between them. The primary functions of the absorbent matrix are the absorption and the retention of the waste that arrives at it. Other characteristics of importance in it are the rapid uptake of the fluid and the distribution of it within the matrix. There are a myriad of proposals to improve these characteristics, such as those mentioned in patents US 4,610,678, 4,765,780, 4,673,402, patents MX 170,21.4 and 171,485, as well as many more known to those skilled in the art. However, this type of matrices, especially those that handle differences in densities within them, or thin matrices, do not have enough integrity to stay together even after they have received fluids and exudates. This represents a serious problem, since once the matrix is split or fragmented, its efficiency decreases and all the characteristics for which it was created, such as absorption, retention and distribution, are affected, diminished or eliminated. Therefore, it is very important to maintain integrity in an absorbent matrix. In this regard, US Pat. No. 5,387,208, to Ashton et al., And assigned to Procter & Gamble discloses an absorbent matrix covered with an integrity layer comprising a type of non-woven fabric bonded to the top layer. This integrity layer may also be placed in an intermediate part of the matrix and / or adjacent to the outer layer of the article. This type of layers help more to the distribution of the liquid and to the non-return of the same to the surface of the article, than to the integrity of the matrix, since they do not fix or stop the movement of the fibers inside it. The use of adhesives in absorbent articles to improve the integrity of the absorbent matrix is known in the art. For example, US Pat. No. 4,573,986, to Procter & Gamble discloses a disposable absorbent article in which the absorbent matrix is attached to the top layer by means of a pattern of adhesive in order to increase the integrity thereof; the use of this type of adhesives does not ensure good integrity, since they tend to have an inadequate adhesion to the cellulose fibers, especially when the article is being used and subject to the movements of the user or when the matrix is moistened .

US Patent 5,397,317, assigned to Procter & Gamble discloses a way to increase the integrity of an absorbent matrix by using columns that exit the bottom layer and / or the top layer and project between the fibers of the absorbent matrix; these columns act by restricting the movements of the fibers of the absorbent matrix, maintaining the integrity of the same. This method can be effective; however, there is no such films on the market with columns perpendicular to them, besides that such films are difficult to handle during the process. The present invention provides an absorbent matrix that incorporates within it an integrity network that allows the cellulosic fibers to entangle therein, forming a firm bond between the fibers and the network, which prevents the matrix from opening or splitting with the movements of the user, even when wet. By making a longitudinal or transverse cut of the matrix, the network is placed, preferably, in the middle part of the matrix, but it can be placed at any height within it. On the other hand, the matrix may contain one or more integrity networks. OBJECTIVES OF THE INVENTION An object of the present invention is to provide a disposable absorbent article whose absorbent matrix does not open or split during use, even when wet. Another object of the invention is to achieve good integrity within a disposable absorbent matrix by a simple and easy to apply method. A further objective of the invention is the use of an integrity network within an absorbent matrix that ensures good integrity thereof during use. A further object of the invention is that the article does not become expensive as a result of the increase in the integrity of the absorbent matrix. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows the absorbent matrix of the present invention with the integrity network placed in the central part thereof. Figures 2 and 2a are samples of two types of integrity networks that can be used for the absorbent matrix of the invention. Figures 3, 4, 5 and 6 show cross sections of the absorbent matrix with alternatives for positioning the integrity network (s) therein. Detailed Description of the Invention The absorbent matrix of a disposable absorbent article is the part thereof that is responsible for absorbing and containing the liquid and semi-liquid exudates that reach it. The matrix must also have the capacity to distribute the liquid and to retain it inside it, avoiding as far as possible its return to the surface of the article. Another important feature in an absorbent matrix is that it is able to maintain its integrity during use, since it will be subjected to tensions in different directions when the user walks, runs, sits, goes to bed or gets up, in addition to that many times the matrix will be subjected to these tensions while being wet. If the matrix suffers ruptures, it stops working at 100%, the distribution is interrupted, there is a risk of leaks and the liquid accumulates in certain areas of the same; if it is completely split, its functionality is null, and it is very uncomfortable for the user. There are a wide variety of absorbent matrices, thick, thin, with catchment and distribution areas, in layers etc., depending on the type of article for which they are used. In any type of matrix it must be ensured that it has the adequate integrity to resist the movements of the user, whether it is dry or wet. Figure 1 shows an absorbent matrix (10) in the shape of "T", although it can have any other shape, depending on the use and the article for which it is intended; the matrix (10) has a front part (12), a rear part (14) and a crotch part (16). This crotch part (16) generally has a minimum width A which will be disposed in the user's crotch during use; the matrix (10) has a total length L and also has an integrity network (20) which is shown separately in figures 2 and 3. The integrity network (20) has a width equal to the width A of the crotch of the matrix and a length equal to the length L of the absorbent matrix (10); however, the preferred width for it is 90% of the width A of the crotch portion of the die (16) and is centered with respect to this crotch portion (16), as can be seen in FIG. Figure 1. However, the network may not span the entire length L of the array. In this case, the integrity network (20) has a minimum length equal to 60% of the total length L of the absorbent matrix (10) and is placed in the area thereof that is considered most convenient to maintain the integrity of the same. The absorbent matrix of this type of articles is preferably formed by defibrated cellulose fibers, with or without superabsorbent material, in such a way that the fibers intertwine with the net (20), forming a type of tie between them and towards the network , which ensures that the matrix will not open or split during use, even with sudden movements of the user. By making a cross section of the matrix, such as that shown in Figures 3 to 6, the net (20) is preferably placed between two layers of the same thickness of absorbent material, ie at the center thereof. However, it can be placed in any other position provided it is between two layers of absorbent material, as shown in figures 4 and 5.

On the other hand, the absorbent matrix (10) can have more than one integrity network (20) inside it, as can be seen in figure 6. The network can be made of polypropylene, rayon, polyethylene, or any other another suitable material for this purpose, and the number of threads per inch thereof can vary between 0.5 x 0.5 and 10 x 10, preferably using a network of between 1 x 1 and 5 x 5 threads per inch. The absorbent matrix (10) of the present invention can be used in a disposable baby diaper, in a disposable incontinent diaper, in a trainer brief, in a feminine towel, or in any other type of disposable absorbent article used to absorb, retain and contain body exudates. While 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

REIVI DICATIONS 1. An absorbent matrix having a total length L, a front part, a back part and a crotch part with a width A, and which is basically formed by fibers of absorbent material, with or without superabsorbent material, characterized in that it contains an integrity network within it in which the cellulosic fibers of the matrix intertwine and unite.
2. An absorbent matrix as described in claim 1, characterized in that the integrity network has a maximum width equal to the width A of the crotch portion of the matrix.
3. An absorbent matrix as described in claim 1, characterized in that the integrity network has a length equal to the length L of the absorbent matrix.
4. An absorbent matrix as described in claim 1, characterized in that the integrity network has a length less than the length L of the absorbent matrix.
5. An absorbent matrix as described in) any of the preceding claims, characterized in that, making a cross section thereof, the integrity network is placed in the central part of the matrix.
6. An absorbent matrix as described in claims 1 to 4, characterized in that, making a cross section thereof, the integrity network is placed at any height, provided there are fibers above and below it.
7. An absorbent matrix as described in claims 1 to 4, characterized in that the matrix has more than one integrity network.
8. An absorbent matrix as described in any of the preceding claims, characterized in that the integrity network has from 0.5 x 0.5 to 10 x 10 threads per inch.
9. An absorbent matrix as described in claims 1 to 7, characterized in that the integrity network has from l x l to 5 x 5 threads per inch.
10. An absorbent matrix as described in any of the preceding claims, characterized in that the integrity network is made of polypropylene.
11. An absorbent matrix as described in claims 1 to 9, characterized in that the integrity network is rayon.
12. An absorbent matrix as described in claims 1 to 9, characterized in that the integrity network is made of polyethylene.
13. An absorbent matrix as described in any of the preceding claims, characterized in that it is used for a disposable baby diaper or incontinent diaper.
14. An absorbent matrix as described in claims 1 to 12, characterized in that it is used for a trainer brief. 16. An absorbent matrix as described in claims 1 to 12, characterized in that it is used for a feminine towel or panty-protector.