CA2608667A1

CA2608667A1 - Elastic laminate

Info

Publication number: CA2608667A1
Application number: CA 2608667
Authority: CA
Inventors: Edward P. Erdman
Original assignee: Tyco Healthcare Retail Services Ag; Edward P. Erdman
Current assignee: Tyco Healthcare Retail Services AG
Priority date: 2005-04-07
Filing date: 2006-04-06
Publication date: 2006-10-19
Also published as: US20060228969A1; MX2007014001A; WO2006110442A1

Abstract

An elasticized panel for a training pant or other absorbent article is disclosed. The panel is of a laminated structure and includes first and second non-woven layers. An elastomeric film is positioned between the first and second non-woven layers. A plurality of elastic strands is positioned between the first and the second non-woven layer. The panel provides improved fit, comfort, and leak resistance for the absorbent article.

Description

ELASTIC LAMINATE

BACKGROUND
1. Technical Field The present disclosure generally relates to absorbent articles, and more particularly to an absorbent article having an elastic laminate structure, that is smooth, low cost and easily manufactured, for improving fit, aesthetics and leakage resistance.

2. Back2round of the Related Art Absorbent articles such as, for example, disposable diapers, adult incontinent pads, sanitary napkins, pantiliners, incontinent garments and the like are generally worn, in cooperation with garments and disposed against a body surface by infants or adult incontinent individuals. The absorbent article is employed to collect and absorb body fluid discharge, such as, for example, blood, menses, urine, aqueous body fluids, mucus, cellular debris and other forms of body discharge. For example, the absorbent article may be disposed between the legs of an individual adjacent a crotch area. The absorbent article is positioned with a garment and drawn into engagement with a body surface of the crotch area to collect body discharge.

As is known, absorbent articles typically include a fluid permeable coverstock for engaging the body surface, a fluid impermeable backsheet and an absorbent core supported therebetween. The backsheet serves as a moisture barrier to prevent fluid leakage to the garment. The absorbent core usually includes a liquid retention material that faces the body surface. The absorbent core can include, for example, loosely formed cellulosic fibers, such as, for example, wood pulp, rayon, or cotton for acquiring and storing -body discharge. The absorbent core may also include tissue wrapping or wadding, and or super absorbent polymer.

Some absorbent article designs typically incorporate elastic elements in the waist, stomach, and leg areas for improving the fit, aesthetics and leakage resistance. The waist and stomach elastic elements increase the flexibility of the absorbent article, allowing the same article to accommodate a greater range of body sizes. In addition, they make the article more form-fitting for the wearer. Leg gather elastic elements and standing leg gathers have also been employed to help reduce leakage from the article when the absorbent cores cannot absorb body exudates fast enough.

Typically, these elastic elements include elastic strands to provide the absorbent article with retractive forces and a desired range of extension. Attachment of the elastic strands to the absorbent article can, however, create undesirable corrugations in the surface of the absorbent article. These disadvantageous corrugations may have a high amplitude and low frequency such that protuberances are formed giving the absorbent article a "bumpy" feel.

In an attempt to overcome these disadvantages, elastic films have been employed. Elastic films, however, may suffer from various drawbacks such as high cost, lower retractive forces and lower range of extension.

It would therefore be desirable to overcome the disadvantages and drawbacks of the prior art by providing an absorbent article, including an elastic laminate having an elastic film and elastic strands. Such an elastic laminate is configured to provide higher retractive forces and a wider range of extension. Desirably the elastic laminate is joined with the absorbent article to provide a substantially smooth surface laminate and comfort. It is contemplated that the elastic laminate is low cost and facilitates easy and efficient manufacture of the absorbent article.

SUMMARY
Accordingly, an absorbent article, including an elastic laminate having an elastic film and elastic strands is disclosed. The elastic laminate is configured to provide higher retractive forces and a wider range of extension, and is joined with the absorbent article to provide a substantially smooth surface laminate and comfort. The elastic laminate is low cost and facilities easy and efficient manufacture of the absorbent article. Objects and advantages of the present disclosure are set forth in part herein and in part will be obvious therefrom, or may be learned by practice of the present disclosure that is realized and attained by the instrumentalities and combinations pointed out in the appended claims for the devices and methods of the present disclosure consisting of its constituent parts, constructions, arrangements, combinations, steps and improvements herein shown and described.

In one particular embodiment, an elasticized panel laminate includes a first nonwoven layer and a second nonwoven layer. An elastomeric film is positioned between the first and second nonwoven layers. The panel further includes a plurality of elastic strands positioned between the first and the second nonwoven layers. The elastic film layer- may include a plurality of spaced apart film strips. The elastic strands can be positioned directly on the film strips, or in the spaces adjacent the strips.

In an alternative embodiment, the elasticized panel laminate may include a plurality of elastic film layers. A first elastic film layer is positioned adjacent the first nonwoven layer, and a second elastic film layer is positioned adjacent the second nonwoven layer.
The layer of elastic strands is positioned between the first and the second elastic film layers.

In another alternative embodiment, the elasticized panel laminate may include a plurality of elastic strand layers. A first elastic strand layer is adjacent the first nonwoven layer. A
second elastic strand layer is positioned adjacent the second nonwoven layer.
The elastic film layer is positioned between the first and the second elastic strand layers.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and features of the present disclosure are set forth with particularity in the appended claims. The present disclosure, as to its organization and manner of operation, together with further objectives and advantages may be understood by reference to the following description, taken in connection with the accompanying drawings, in which:

FIGURE 1 is a perspective view of an absorbent article in accordance with the principles of the present disclosure;

FIGURE 2 is an exploded perspective view of an elastic panel of the absorbent article shown in=FIGURE 1;

FIGURE 2A is an exploded perspective view of an alternate embodiment of the elastic panel shown in FIGURE 2;

FIGURE 2B is an exploded perspective view of another alternate embodiment of the elastic panel shown in FIGURE 2;

FIGURE 3 is an exploded perspective view of another alternate embodiment of the elastic panel shown in FIGURE 2;

FIGURE 3A is a plan view of a portion of an alternate embodiment of the elastic panel shown in FIGURE 3; and FIGURE 3B is a cutaway view of an elastic film or elastic strand of the elastic panel shown in FIGURE 3 taken along plane 3B in FIGURE 3A.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The exemplary embodiments of the absorbent article and methods of use disclosed are discussed in ternis of fluid absorbent articles, and more particularly, in terms of an absorbent article including an elastic laminate structure that is smooth, low cost and easily manufactured for improving fit, aesthetics and leakage resistance. The presently disclosed absorbent article is contemplated to be employed with, for example, training pants, adult incontinent products, disposable diapers, and other incontinent articles.

In the discussion that follows, the term "body-facing surface" refers to a portion of a structure that is oriented towards a body surface, and the "garment-facing surface" refers to a portion of the structure that is oriented towards a garment and is typically opposing the body-facing surface and may be referred to as such. As used herein, the term "body surface" refers to a portion of an individual's body that the absorbent article is disposed with for collecting and absorbing fluid discharge from the individual. As used herein, the term "absorbent article,"
"absorbent garment" or "garment" refers to garments that absorb and contain body waste, and more specifically, refers to garments that are placed against or in proximity to the body of the wearer to absorb and contain the various body discharges and wastes.

A non-exhaustive list of examples of absorbent articles includes training pants, diapers, diaper covers, disposable diapers, feminine hygiene products and adult incontinence products.
The term absorbent articles includes all variations of absorbent garments, including disposable absorbent garments that are intended to be discarded or partially discarded after a single use and unitary disposable absorbent garments that have essentially a single structure. As used herein, the term "training pants" refers to an absorbent article generally worn by children about the lower torso. The absorbent article may be disposable or partially discarded after a single use.
The absorbent article can be a unitary structure or include replaceable inserts or interchangeable parts.

Absorbent articles and diapers may have a number of different constructions.
In each of these constructions it is generally the case that an absorbent core is disposed between a liquid pervious, body-facing topsheet and a liquid impervious, exterior facing backsheet. In some cases, one or both of the topsheet and backsheet may be shaped to form a pant-like article, such as a training pant. In other cases, the topsheet, backsheet and absorbent core may be formed as a discrete assembly that is placed on a main chassis layer and the chassis layer is shaped to form~ a pant-like absorbent article. The absorbent article may be provided to the consumer in the fully assembled pant-like shape or may be partially pant-like and require the consumer to take the final steps necessary to form the final pant-like shape. Training pants are typically fully formed and applied by pulling the absorbent article over a child's legs. For a diaper application, an open article is provided and wrapped about a child's waist, such as by manually fastening one or more fasteners or fastener tabs.

The following discussion includes a description of the absorbent article in accordance with the present disclosure. Reference will now be made in detail to the exemplary embodiments of the disclosure, which are illustrated in the accompanying Figures.

Turning now to the Figures, wherein like components are designated by like reference numerals throughout the several views. Referring to Figure 1, there is a perspective view illustrating one embodiment of an absorbent article in accordance with the present invention.
The absorbent article 50 as illustrated in Figure 1 is of a pull-on or training pant type and comprises a main body 30 which has a waist hole 32 and a pair of leg holes 34.
The main body 30 includes a waist gather 36 disposed along the periphery of the waist hole 32, and a leg gather 38 disposed along the periphery of each of the leg holes 34.

The leg gather 38 is formed by the contracting force of elastic regions 40 incorporated therein. Other elastic regions 42 are provided for improved fitting of the main body 30 to a waist portion of a wearer. The main body 30 comprises a backsheet 44 formed of liquid impermeable material, a topsheet 46 formed of liquid permeable material, preferably hydrophilic material, and an absorbeint core 48 interposed therebetween. According to the present disclosure, the elastic regions 40, 42, lateral side portions 52, waist portions 54 and body sections 56 each include an elastic laminate panel 10 as described below. Each portion may include one or a plurality of elastic laminate panels 10 according to requirements of a particular application.

With reference to Figures 2, 2A, 2B and 3, an elastic laminate according to the present disclosure is shown. In one illustrative embodiment, as sliown in Figure 2, the elastic panel 10 includes a first outer surface or layer 12 of nonwoven material, a layer of elongated elastic film 16, a layer of elastic strands 18, and a second outer layer 14 of nonwoven material. The layers 12, 14, 16, 18 are joined together to form a substantially unitary structure or panel 10. It is contemplated that layer 12 may alternatively be forrned of a film, apertured filni, tissue, or woven material.

The panel 10 is formed by positioning a layer of tensioned elastic. strands 18 between the elongated elastic film 16 and either of the nonwoven layers 12, 14, and joining the layers 12, 14, 16, 18 together. Then the tension in the elastic strands 18 and film 16 is released thereby permitting them to~ contract and draw the outer layers 12, 14 into corrugations (pleats) of a desired thickness (amplitude) and frequency. When the corrugations are drawn apart, the panel has resilient elastic properties. The elasticized panel 10 may be formed into the elastic regions 40, 42 or any portion of the training pant 50 using any suitable method, such as adhesive bonding or ultrasonic bonding, as will be appreciated by those of ordinary skill in the art.

The elastic strands 18 can be of suitable elastic material, such as, for example, natural rubber, butyl rubber or other synthetic rubber, urethane, or elastomeric materials such as spandex, which is marketed under various names, including LYCRA (DuPont), GLOSPANTM
(Globe) and SYSTEM 7000TM (Fulflex). The elastic film layer 16 can be, for example, a urethane based elastic or stretch film, such as EXTRAFLEX available from Tredegar Film Products of Richmond, Va. The elastic film layer 16 may also be formed from other types of elastic films, multidirectional elastic aggregate such as elastic webbing, netting, scrim elastic, or foam. The present invention is not limited to any particular elastic material or to any particular shape, size or number of elastics. The non-woven layers 12, 14 may be a conventional spunbond-meltblown-spunbond (SMS) material sold under the trade designation polypropylene non-woven by Avgol of Holon, Israel. The SMS material may be of any suitable weight, for example, 13.5 grams per square meter (gsm), and any suitable thickness, for example, 0.6 mil.

Other suitable nonwovens of similar weights or thicknesses may be carded, spunbond, or spunlaced materials manufactured by, for example, Polymer Group, Inc. (PGI) of Mooresville, North Carolina, BBA Nonwovens Simpsonville, Inc. of Simpsonville, South Carolina and Freudenberg Nonwovens of Durham, North Carolina.

The layers 12, 14, 16, 18 may be bonded using joining methods known in the art, such as, for example, pressure bonds, thermal bonds, ultrasonic bonds, adhesives, other attachment means, or combinations of different bonding methods. In the illustrative embodiment of the elasticized panel 10, as shown in Figure 2, the elastic film layer 16 is bonded to the first nonwoven layer 12. The elastic strands 18 are bonded to the elastic film layer 16 and the second nonwoven layer 14. Alternatively, in configurations of the panel 10 described below with reference to Figures 2A, 2B, 3 and 3A, the elastic film layer 16 may be attached to either of the nonwoven layers 12, 14. The elastic strands 18 may be attached to either the elastic film layer 16, the nonwovens layers 12, 14, or both.

The film layer 16 can be attached to either of the nonwoven layers 12, 14 using adhesive.
The adhesive can be applied, for example, as a solid coat to either the film or nonwoven.
Alternately, the adhesive can be applied in either a channeled or uniform pattern. Suitable adhesives include HL-1258 by H. B. Fuller Company of St. Paul, Minn., Findley 2031 and H2587-01 by Ato Findley Inc. of Wauwatosa, Wis., DISPOMELT 34-5665 by National Starch Co. of Bridgewater, N.J., DISPOMELTO 34-578A by National Starch Co. of Bridgewater, N.J., and HL 1486UZP, which is available from H. B. Fuller Company of St. Paul, Minn. Alternately, the film layer 16 can be joined to the nonwoven 12, 14 using ultrasonic bonding applied in either a channeled or uniform pattern.

The strands 18 can be attached to the either the film layer 16, the nonwoven layers 12, 14 or both using adhesive, ultrasonic, thermal, or pressure bonding, or the like.
Such attachment of the strands 18 can be performed in either a continuous or intermittent manner.
In this connection, it is noted that increasing the binding of the tensioned elastic strands 18 to the nonwoven or film can cause the strands 18 to become less elastic. Accordingly, the present disclosure provides for applying less glue/adhesive on the strands 18 in order to increase the elasticity of the formed panel 10. In addition, the strands 18 may be partially or wholly placed within channels (not shown) that have no glue so to form, for example, grooves, shapes, or undulations that enhance functionality of the panel 10.

It is envisioned that the elasticized panel 10 may include additional layers of strands 18, elastic films 16, nonwovens 12, 14, or other materials arranged in various configurations suitable for a variety of different applications. For example, while the elasticized panel 10 of Figure 2 includes a single layer of strands 18, it is contemplated that the panel 10 can include a plurality of strand layers 18. In an illustrative embodiment shown in Figure 2A, the elasticized panel 10 includes first nonwoven layer 12. The panel 10 further includes second nonwoven layer 14.
Elastic film layer 16 is disposed intermediate the first and second nonwovens 12, 14. A first layer of elastic strands 18A is disposed between the first nonwoven 12 and the elastic film 16.
The panel 10 further includes at least a second layer of strands 18B disposed between the second nonwoven 14 and the film 16. It is envisioned that each of the strand layers 18A, 18B are attached (explained in further detail below) to either an adjacent nonwoven or film or both.

The elasticized panel 10 can include a plurality of elastic film layers 16. In an illustrative embodiment shown in Figure 2B, the panel 10 includes first nonwoven layer 12.
Second nonwoven layer 14 is provided. The panel 10 further includes elastic strand layer 18 intermediate the first and second nonwovens 12, 14. A first elastic film, such as, for example, a first layer of film 16A is disposed between the strand layer 18 and the first nonwoven layer 12.
The panel 10 further includes a second elastic film, such as, for example, a second film layer 18B
disposed between the strand layer 18 and the second nonwoven 14.

In an alternate embodiment of the elasticized panel 10, the elastic film layer can comprise a plurality of strips. In one example, as shown in Figure 3, the film layer 16 includes a first film strip 28 and a second film strip 29 spaced apart from the first strip 28. This configuration minimizes costs since less film is used. In addition, one or more elastic strands can be disposed with the layer gf film strips to form a panel 10 having desired performance criteria. For example, the strands can be positioned directly on the film strips, or in the spaces adjacent the strips. In an illustrative embodiment, as shown in Figure 3A, the elastic layer 16 includes a first set of elastic strands 22 positioned on the first film strip 28. The layer 16 further includes a second strand set 24 disposed in the space between the first and second film strips 28, 29. A
third strand set 26 is positioned in the space to the left of the first strip 28. It is envisioned that the strands and film can be arranged in other various configurations to form a panel 10 having desired operating characteristics.

The elastic strands and elastic films, described above, can be differentiated using an identifying aspect ratio corresponding to a particular film or web versus a particular strand, fiber, filament, rope or yam. In an alternate embodiment, the aspect ratio is determined based on the ratio of the longer dimension to the shorter dimension. For example, as shown in Figure 3B, the dimensional parameters of the strand and film components can be defined using the cross sectional dimensions of the particular component as represented by the geometry shown, as taken along plane 3B on Figure 3A. The greater thickness x represents the width, of a strand or film, and is the numerator of the aspect ratio. The lesser thickness represents.the height y of a strand or film, and is the denominator of the aspect ratio. It is contemplated that an aspect ratio of <
(less than) 3:1 defines a strand, and an aspect ratio of ?(greater than or equal to) 3:1 defines a film. Other aspect ratios for strands and films are also envisioned. As indicated in the following table, elastic strands have aspect ratios of < 3.

Elastic Largest Smallest Aspect Ratio Manufacturer - Elastic size Dimension Dimensions (mm) (mm) (Largest /
Smallest) Invista - Lycra 220 dtex 0.3 0.2 1_5 Invista - Lycra 620 dtex 0.4 0.3 1.3 Invista - Lycra 680 dtex 0.5 0.4 1.3 lnvista - Lycra 940 dtex 0.5 0.4 1.3 Invista - Lycra 1100 dtex 0.6 0.4 1.5 Invista - Lycra 1520 dtex 0.6 0.4 1.5 Hyosung - Creora 180 den 0.3 0.3 1.0 Hyosung - Creora 210 den 0.2 0.2 1.0 Hyosung - Creora 300 den 0.3 0.3 1.0 As described above, an economical elastic film layer 16 is combined with a number of elastic strands 18 to form an elasticized panel 10 having smooth outer surfaces 12, 14 (i.e., low amplitude, high frequency corrugations), and also having desired retractive forces and range of extension. The film-to-nonwoven bonding across the wide surfaces of the elastic film 16 provides the resulting smoothness of the elasticized panel 10. The elastic strands 18 supplement the retractive forces of the elastic film 16, and provide the higher retractive forces and wider range of extension of the elasticized panel 10. The elasticized panel 10*is low-cost and easy to manufacture.

In an alternate embodiment, various components of elasticized panel 10 may elongated relative to other components upon assembly of panel 10. The percentage of elongation of a particular component is defined as the degree of difference of an elongated length of an elastomeric component versus a relaxed, non-elongated length of the same component. This can be expressed by the equation: % Elongation = (elongated length - relaxed length)/ (relaxed length) x 100. Thus, a component such as elastic strands 18 may have a percentage of elongation that is not equal to the percentage of elongation of elastic film 16. For example, elastic strands 18 can have a percentage of elongation that is greater than a percentage of elongation of elastic film 16 when the components of panel 10 are laminated together. It is contemplated that elastic strands 18 may have a percentage of elongation that is less than a percentage of elongation elastic film 16, or alternatively, the percentages of elongation for the components of elasticized panel 10 may be equivalent.

In an alternate embodiment, elastic film layer(s) 16 and elastic strands 18 include altemative visual indicia to indicate alternate attachment positions of closure mechanisms for adjusting the fit of the article to a desired degree. It is contemplated that the visual indicia may include altemative coloring, designs, etc. For example, elastic film layer 16 may be colored blue and elastic strands 18 may be colored pink. It is envisioned that layer 16 and strands 18 may have various combinations of visually contrasting colors. It is further envisioned that layer 16 and strands 18 may be colored across a range of shading.

The claims are intended to cover all of the foregoing classes of absorbent articles, without limitation, whether disposable, unitary or otherwise. These classifications are used interchangeably throughout the specification, but are not intended to limit the claimed invention.
The invention will be understood to encompass, without limitation, all classes of absorbent articles, including those described above.

The invention of the present disclosure may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

li

Claims

1. An elasticized panel comprising:
a first nonwoven layer;

a second nonwoven layer;

an elastomeric film layer positioned between the first and second nonwoven layers; and a plurality of elastic strands positioned between the first and the second nonwoven layers.

2. The elasticized panel as recited in claim 1, further including a plurality of elastomeric films.

3. The elasticized panel as recited in claim 1, wherein the first nonwoven layer defines a first outer surface of the panel, and the second nonwoven layer is parallel to the first nonwoven layer and defines a second outer surface of the panel.

4. The elasticized panel as recited in claim 1, wherein the strands are between the elastomeric film layer and one of the first and second nonwoven layers.

5. The elasticized panel as recited in claim 1, wherein the strands exert a retractive force greater than the elastomeric film layer.

6. The elasticized panel as recited in claim 1, wherein a percentage of elongation of the elastomeric film layer and a percentage of elongation of the strands are not equal during lamination.

7. The elasticized panel as recited in claim 1, wherein the elastic strands have a percentage of elongation that is greater than a percentage of elongation of the elastomeric film layer during lamination.

8. The elasticized panel as recited in claim 1, wherein the elastomeric film layer includes a plurality of spaced apart elasticized film strips.

9. The elasticized panel as recited in claim 8, wherein the spaced apart film strips are parallel.

10. The elasticized panel as recited in claim 8, wherein the elastomeric film layer further includes elastic strands positioned in spaces adjacent the film strips.

11. The elasticized panel as recited in claim 8, wherein the elastomeric film layer includes at least one elastic strand positioned directly on at least one of the film strips.

12. An elasticized panel comprising:
a first nonwoven outer layer;

a second nonwoven outer layer;

a first elastic film layer adjacent the first nonwoven outer layer;

a second elastic film layer adjacent the second nonwoven outer layer; and a layer of elastic strands positioned between the first and the second elastic film layers.

13. The elasticized panel as recited in claim 12, wherein bonding between the layers of the panel is accomplished by one or more of pressure bonds, thermal bonds, ultrasonic bonds, or adhesives.

14. The elasticized panel as recited in claim 13, wherein the adhesive is applied in one of a solid coat or in a pattern.

15. The elasticized panel as recited in claim 14, wherein the pattern is a channeled pattern.

16. The elasticized panel as recited in claim 14, wherein the pattern has a uniform character.

17. The elasticized panel as recited in claim 12, wherein the strands are attached to the film in a continuous manner.

18. The elasticized panel as recited in claim 12, wherein the strands are attached to the film in an intermittent manner.

19. An elasticized panel comprising:
a first nonwoven outer layer;

a second nonwoven outer layer;

a first elastic strand layer adjacent the first nonwoven outer layer;

a second elastic strand layer adjacent the second nonwoven outer layer; and a layer of elastic film positioned between the first and the second elastic strand layers.

20. The elasticized panel as recited in claim 19, wherein at least some strands are placed within unglued channels formed in either the nonwoven layers or the film layer.

21. An elasticized panel comprising:
a first layer;

a second layer;

an elastomeric film layer positioned between the first and second layers; and a plurality of elastic strands positioned between the first and the second layers.

22. The elasticized panel as recited in claim 10, wherein an aspect ratio of less than 3:1 defines a strand, and an aspect ratio of greater than or equal to 3:1 defines a film.