KR20010024773A - Ultralight, Converting Friendly, Nonwoven Fabric - Google Patents

Abstract

The present invention relates to ultralight nonwovens useful as exterior fabrics for forming various personal care products, including nonwoven webs having a basis weight of less than 13.56 g / m ² (0.40 osy) and having a fibrous structure of individual fibers or filaments. . 40.69 g / m ² (1.20 osy) PR, in which a pattern of bonding areas is formed on the surface of the web, the web being calculated by multiplying the poison ratio of the nonwoven web at the 10% longitudinal elongation by the basis weight of the nonwoven web. It has dimensional stability characterized by the following coefficients. The junction region can be continuous or discontinuous.

Description

Ultralight nonwoven fabric with easy conversion {Ultralight, Converting Friendly, Nonwoven Fabric}

Lightweight nonwovens are often used to provide exterior sheathing for absorbent and barrier laminated articles. Examples of such nonwovens are spunbond, meltblown and carded web nonwovens. Such webs can form bodyside sheaths in absorbent products such as underpads and diapers. The sheath serves to form an inner coverstock for personal care products such as diapers.

In a diaper, the sheath is a liner disposed between the infant skin and the absorbent material of the diaper. In such a position, the function of the liner must be permeable to the fluid to be absorbed by the absorbent material so that the fluid is absorbed and removed as quickly as possible from the infant's skin. These sheaths provide wear resistant or cloth-like veneers on the absorbent material in these products. Spunbond sheaths are also used in products such as indoor wipers under the Kimberly-Clark trademark. In these particular wipers, the absorbent is provided by a meltblown core with a spunbond sheath that imparts abrasion resistance and a cloth-like feel to the product.

Spunbond-meltblown-spunbond (SMS) barrier fabrics use spunbond sheaths to achieve the same functionality as sheaths in Crew® branded wipers. Carded or spunbond webs are often used with film barriers to provide a cloth-like veneer on the barrier. Examples of such film barriers are the Mayo stand and back table covers used during surgery and outer covers for personal care products.

The exterior mentioned above is somewhat similar to the wood veneer used in the manufacture of furniture. As in the manufacture of veneer furniture, it is desirable to use veneer as light as possible in terms of cost. Another advantage of using less material in disposable products is less waste when these products are disposed of.

Machines for making personal hygiene products, such as diapers, must continuously process multiple webs. Such processing is known industrially as "converting". The machine's mass production line positions other webs on top of one web, glues the positioned webs, glues the positioned webs, joins the positioned webs, and turns the bonded webs into the desired shape. Performing a conversion involves a variety of tasks to tailor. This lamination process may involve the spreading of the sheath for the entire bonded laminate to another substrate in the case of the manufacture of SMS, the spread to the product converting machine for the peripheral bonded lamination on the absorbent layer of the personal care product.

During these various converting operations, the web must be pulled around the roll and stretched in both longitudinal (MD) and transverse (CD) ways. If more than one web breaks during this process, such breakdown will tend to contaminate several stations of the machine and production will stop until the machine can be cleaned to clean up the contamination. Therefore, the strength of the webs used in such converting operations should be adequate to withstand such processing without frequent destruction.

In addition, in order to form a product that consumers like aesthetics, each web must be able to undergo such elongation while still maintaining its position with other webs so that operations such as glueing, bonding and cutting can be performed properly. do. Therefore, the web must have adequate dimensional stability to withstand permanent deformation during machining. For example, the web should have adequate dimensional stability to withstand the tendency to "neck-in" when the web is stretched in the longitudinal direction. Fabrics that are generally "neck-in" will warp when they are converted into a product, being longer in the longitudinal direction and shorter in the transverse direction.

As mentioned above, lightweight webs are preferred because they can reduce the overall weight of the product and the amount of material needed for the sheath, thereby lowering the price of the entire product. Although lighter is preferred, known fabric-like nonwovens lose dimensional stability when their weight is reduced. In particular, they tend to be neck-in laterally as they unfold and stretch during the converting process. This tendency of sheathing to the neck-in makes it difficult to achieve process control, especially the desired width of the sheathing of the finished laminate.

One solution to the neck-in problem is to increase the degree of bonding in the enclosure. Another possible solution is to change the typical point bond to a whole fiber inside bond. Nylon spunbond (Cerex®) and polyester spunbond (Reemay®) are available in light weight and are dimensionally stable. In these products, bonding generally occurs at each fiber to fiber contact point, providing dimensional stability. Polyolefin spunbond materials commercially available from AMOCO also have these properties. While achieving the desired dimensional stability, these materials do not have the surface fiber fluidity required to impart the cloth-like tactile feel required for most personal care product exteriors.

Previously, the above mentioned requirements of tensile strength and dimensional stability prevented the use of webs lighter than about 13.56 g / m ² (about 0.40 oz / yd ² (osy)) for the sheath. Webs lighter than 13.56 g / m ² (0.40 osy) lack the required tensile strength and / or dimensional stability and are therefore not considered “converter friendly”. Webs that are not easy converters are currently available for commercial products, but their dimensional stability is insufficient to convert them into products without significant waste generation and downtime in the converting process.

<Object and Summary of the Present Invention>

It is an object of the present invention to provide a lightweight nonwoven that can be used to form a sheath.

It is another object of the present invention to provide a sheath formed of lightweight nonwoven fabric in other products such as personal care products or laminates.

It is another object of the present invention to provide an ultralight nonwoven fabric having a basis weight of less than about 13.56 g / m ² (about 0.40 osy) and suitable for forming a sheath of other products such as personal care products or laminates.

Further objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or will be learned by practice of the invention. The objects and advantages of the invention may be realized and attained through means and combinations particularly pointed out in the appended claims.

To achieve the object of the present invention and in accordance with the intention of the present invention, as specifically and broadly described herein, ultralight nonwoven webs are provided and exhibit dimensional stability comparable to that of heavier fabrics. Ultralight nonwoven sheaths that withstand neck-in during lamination or converting provide surface fiber fluidity, resulting in a material with a cloth-like tactile feel. The sheath may be wettable for use in absorbent articles or non-wettable for use in barrier articles.

Specifically, the present invention relates to a nonwoven web having a basis weight of 13.56 g / m ² (0.40 osy) and using a continuous bond pattern or a high density discontinuous bond pattern. Discontinuous bonding patterns result from the calendering of the web, resulting in a continuous pattern of bonding regions as opposed to individual discrete pinpoint bonding. High density discontinuous bonding patterns result in multiple pinpoint bonds, typically pin densities of 62 pinpoints / cm ² (400 pinpoints / inch ² ) or more.

The ultralight materials of the present invention will generally retain their shape during elongation and will not exhibit substantial "neck-in" under stress. The ultralight fabric of the present invention minimizes this “neck-in” and has dimensional stability comparable to heavier (base weight greater than 13.56 g / m ² (about 0.40 osy)) fabrics.

The fabrics of the present invention are fabrics of various types, including meltblown, spunbond, bicomponent and crimped fibers, as disclosed in US Pat. No. 5,418,045 to Pike et al., Which is incorporated by reference in its entirety herein. It can be prepared from. The ultralight fabrics of the present invention are suitable for various absorbent and barrier medical applications such as surgical gowns, drapes, sterile wraps, as well as disposable personal hygiene absorbent articles, such as bandages, diapers, training pants, urinary incontinence garments, feminine health products such as sanitary napkins, and bandages. It can be used for liner and sheath materials in products. In addition, the invention can be used in a variety of laminates such as elastic and film laminates, outer covers, side plates, diaper ears, absorbent liners, wipers and spunbond-meltblown-spunbond materials. Can be.

The accompanying drawings, which are incorporated in and constitute a part of this, illustrate one embodiment of the invention and, together with the description, serve to explain the principles of the invention.

FIELD OF THE INVENTION The present invention relates to ultralight nonwovens possessing the appropriate strength and aesthetics to function as veneers or facings on fabric-like laminates. The sheath of the present invention can be used in absorbent personal care products such as diapers.

The complete and authoritative disclosure of the invention, including the best mode of the invention, is described in more detail to those skilled in the art in the remainder of the specification, including reference to the accompanying drawings.

1 is a top view of a patterned non-bonded nonwoven fabric of the present invention.

FIG. 2 is a side view of a cross section of the pattern non-bonded nonwoven of FIG. 1. FIG.

3 is a top view of another embodiment of a nonwoven with a discontinuous bonding pattern.

4 is a schematic side view of a process and apparatus for making a patterned non-bonded nonwoven of the present invention.

5 is a partial perspective view of a pattern roll that may be used in accordance with the process and apparatus of FIG. 4.

6 is a perspective view of a disposable diaper with a fabric of the present invention that forms a liner or sheath covering an absorbent core.

FIG. 7 is a graph showing the Poisson ratio of non-bonded patterned fabrics of various patterns at a given fiber size (denier) and a given fabric basis weight (g / m ² (osy).

FIG. 8 is a graph showing the poison ratio of various patterns of non-bonded patterned fabrics and various control fabrics at a given fiber size (denier) and a given fabric basis weight (g / m ² (osy)).

FIG. 9 is a graph showing the poison ratio of various discrete bond pattern fabrics at a given fiber size (denier) and a given fabric basis weight (g / m ² (osy)).

FIG. 10 is a graph showing the poison ratios of various discrete bond pattern fabrics and various control fabrics at a given fiber size (denier) and a given fabric basis weight (g / m ² (osy)).

FIG. 11 is a graph showing the poison ratios of various patterned non-bonded fabrics, various discrete bonded patterned fabrics, and various control fabrics at a given fiber size (denier) and a given fabric basis weight (g / m ² (osy)).

<Detailed Description of the Preferred Embodiments>

Embodiments of the invention will now be described in detail, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various changes and modifications can be made in the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment can be used in another embodiment to yield another embodiment. Thus, it is intended that the present invention cover such modifications and variations as appended claims and their equivalents. Like numbers refer to like elements throughout the drawings and description.

Justice

A “spunbonded fiber” is a small diameter fiber formed by extruding molten thermoplastic as a filament from a plurality of fine, generally circular spinneret capillaries having a diameter of the filament being extruded and then having a rapidly decreasing diameter Point to. Examples of spunbonded fibers include US Pat. No. 4,340,563 to Appel et al., US Pat. No. 3,692,618 to Dorschner et al., US Pat. No. 3,802,817 to Matsuki et al., And Kinney. US Pat. No. 3,338,992, Kinney US Pat. No. 3,341,394, Hartman US Pat. No. 3,502,763, and Dobo et al. US Pat. No. 3,542,615. Spunbond fibers are generally continuous and have an average diameter (from at least 10 samples) of greater than 7 μm, in particular about 10-40 μm. The fibers also include U.S. Patent 5,277,976 to Hogle et al., U.S. Patent 5,466,410 to Hills, U.S. Patent 5,069,970 to Lagman et al. , And Ragman et al., US Pat. No. 5,057,368.

A “meltblown fiber” is extruded through a number of fine, generally circular die capillaries into a high speed, generally hot gas (eg air) stream that concentrates the molten thermoplastic as molten threads or filaments. By which the filaments of the molten thermoplastic material are tapered to reduce to a diameter which may be a microfiber diameter. The meltblown fibers are then carried by the high velocity gas stream and are deposited on a collecting surface to form a web of irregularly dispersed meltblown fibers. Such a method is disclosed, for example, in US Pat. No. 3,849,241 to Buntin et al. Meltblown fibers are continuous or discontinuous fine fibers and generally have an average diameter of less than 10 μm.

"Conjugate fiber" refers to fibers formed from two or more polymer sources that are extruded from separate extruders but spun together to form a fiber. Composite fibers are sometimes also referred to as multicomponent or bicomponent fibers. The composite fibers may be monocomponent fibers but the polymers are generally different from one another. The polymers are arranged in discrete zones positioned substantially constant across the cross-sectional area of the composite fibers and extend continuously along the length of the composite fibers. Such an arrangement of composite fibers may be, for example, a sheath / core arrangement in which one polymer is surrounded by another polymer, or may be in a parallel arrangement, a pi arrangement or a "depth of view" arrangement. Composite fibers are taught in US Pat. No. 5,108,820 to Kaneko et al., US Pat. No. 5,336,552 to Strack et al. And US Pat. No. 5,382,400 to Pike et al. For bicomponent fibers, the polymer may be present in 75/25, 50/50, 25/75 or any other desired ratio. The fibers may also have shapes such as those described in US Pat. No. 5,277,976 to Hogle et al., US Pat. No. 5,069,970 to Ragman et al. And US Pat. No. 5,057,368 to Lagman et al., Which describe fibers having an unusual shape. Which is hereby incorporated by reference in its entirety. Polymers useful for forming composite fibers include polymers commonly used in spunbonding and meltblowing processes, including various polyolefins, nylons, polyesters, and the like.

"Bicomponent fiber" refers to fibers formed from two or more polymers extruded as a blend from the same extruder. Bicomponent fibers do not have various polymer components arranged in separate zones that are relatively uniform across the cross-sectional area of the fiber, and the various polymers are usually not continuous along the entire length of the fiber, but instead have irregular starting and ending blood Forms brill or protopibril. Bicomponent fibers are sometimes referred to as multicomponent fibers. Fibers of this general type are discussed, for example, in US Pat. No. 5,108,827 to Gesner. Bicomponent and bicomponent fibers are also described by John A. Manson and Leslie H. Sperling in Polymer Blend and Composites, All Rights Reserved 1976, Plenum Press, a subsidiary of Plenum Publishing Corporation. Plenum Press, New York, IBSN 0-306-30831-2, pp. 273-277.

"Bonded carded web" refers to a web that passes through a comb or carding machine where the staple fibers are separated or scattered and aligned vertically to form a longitudinally-oriented fibrous nonwoven web. These fibers are usually purchased in bales and placed in an opener / blend or picker that separates the fibers before the carding machine. Once the web is formed, it is joined by one or more known bonding methods. One such bonding method is powder bonding, in which powdery adhesives are distributed throughout the web, which is usually activated by heating the web and adhesive with hot air. Another suitable bonding method is pattern bonding, using a heating calender roll or an ultrasonic bonding device to bond the fibers together, usually in a localized bonding pattern, although the web may be bonded across its entire surface if desired. In particular when using bicomponent staple fibers, another suitable and well known joining method is aeration bonding.

"Airlaying" is a known method that can form a fibrous nonwoven layer. In the airlaying process, bundles of small fibers having a typical length of about 3 to about 19 millimeters are separated and sent to an air supply, which is usually attached onto the forming screen with the aid of a vacuum supply. The irregularly attached fibers are then bonded to each other using, for example, hot air or spray adhesive.

By aeration bonding is meant a method of bonding bicomponent fiber nonwoven webs in which air is passed through the web sufficiently hot to melt one of the polymers forming the web fibers. The air speed is 30.48 to 152.4 m / min (100 to 500 ft / min) and the residence time can be on the order of 6 seconds. The polymer is melted and restocked to bond. Aeration bonds are relatively limited in variety, and aeration bonds require melting at least one component to achieve bonding, so webs with two components such as composite fibers or webs containing individual adhesives, such as low melting point fibers or adhesive additives Limited to. In the ventilator, air at a temperature higher than the melting temperature of one component and lower than the melting temperature of another component is directed to the perforation roller supporting the web. Alternatively, the ventilator adapters may be arranged flat, where air is directed on the web in a direction perpendicular to the web. The operating conditions of the two shaping devices are similar, with the main difference being the layout shape of the web during the joining. The heated air integrates the web by forming a bond between the filaments by melting the polymer component that melts at lower temperatures.

As used herein, "pattern unbonded" or "point unbonded" means a fiber pattern having a continuous bond region that defines a number of individual non-bonded regions. This pattern is shown in FIGS. 1 and 2. The fibers or filaments in the individual non-bonded regions are dimensionally stabilized by continuous bonded regions surrounding or surrounding each non-bonded region. Non-bonded regions are especially designed so that there is a space between the fibers or filaments in the non-bonded regions.

As used herein, "discontinuous bond pattern" or "point bonded" or "point bonded" means a fiber pattern having discrete bond regions that are not continuous. Unlike the point unbonded pattern, the point bonded pattern has a number of separate bonded points surrounded by the unbonded regions.

Although various patterns of calendar rolls have been developed for aesthetic as well as functional reasons, these patterns will typically not cause the high density discontinuous bonding pattern used in the present invention as defined below. One example of a pattern has dots and a Hansen Pennings or “H & P” pattern as taught in US Pat. No. 3,855,046 to Hansen and Pennings, which is incorporated herein by reference in its entirety. As having about 30% junction area and about 31 junctions / cm ² (about 200 junctions per square inch). The H & P pattern has a square point or pin joint area where each pin has a lateral dimension of 0.965 mm (0.038 inch), the spacing between the pin is 1.778 mm (0.070 inch), and the bonding depth is 0.584 mm (0.023 inch). Have The resulting pattern has a junction area of about 29.5%. Another typical point bond pattern has a lateral dimension of 0.94 mm (0.037 inch), 15% of the space between the pin and the pin with a square pin with a 2.464 mm (0.097 inch) and a bond depth of 0.991 mm (0.039 inch). Extended Hansen Pennings or “EHP” bond pattern to form a bond region. Another typical point bond pattern, named "714," has a side dimension of 0.584 mm (0.023 inch) with each pin, a distance of 1.575 mm (0.062 inch) between the pin and the pin, and a depth of bond of 0.838 mm (0.033). Square fin junction area). The resulting pattern has about 15% junction area. Another common pattern is a C-star pattern with approximately 16.9% junction area. The C-Star pattern has a "corduroy" design with transverse bars or star stars. Other common patterns are diamond patterns with repeated and slightly offset diamonds with a joint area of about 16% and reticulated patterns with a joint area of about 19%, such as for example window screens, as its name suggests. Typically, the bonding area% varies from about 10% to about 30% of the fabric laminated web area. As is well known in the art, spot bonding bonds filaments and fibers within each layer to provide preservation to each individual layer as well as to keep the laminates together.

As used herein, the term “high density discontinuous bonding pattern” is a discontinuous bonding pattern having an overall bonding density of about 62 fins / cm ² (about 400 fins / inch ² ) or more.

As used herein, the term " longitudinal " or " MD " means the longitudinal direction of the fibers produced on the machine making the fabric. The term "transverse" or "CD" refers to the width of the fiber, ie, generally perpendicular to the MD.

As used herein, the term "numerically stable" refers to a fabric that withstands deformations such as the neck-in described herein when converting. "Numerically stable" is a relative term that distinguishes a particular fabric from other fabrics having a similar basis weight and / or fiber size. Numerical stability is defined quantitatively by measuring the poison ratio at 10% longitudinal elongation as described.

Test Methods

The following method was used to obtain the data shown in the tables herein.

Basis Weight: The basis weights of the various materials described herein were determined by Federal Test Method No. 191A / 5041. The sample specimen size of the sample material was 15.24 x 15.24 cm, and three values were averaged for each material. Recorded values are average values.

Denier: A "denier" is a unit of the size of the fibers constituting the web, in particular the fineness of the fibers, measured in grams of filament 9000 m. This is represented by "dpf" which means "denier / filament".

Fabric Thickness: The "5 inch bulk drying" parameter is measured in cm and is a measure of the thickness of the fabric. The thickness of the textile fabric is defined as the distance between the top and bottom surfaces of the material surface measured under the specified pressure. The average thickness of the textile material is usually determined by measuring the distance of the moving plane taken away from the parallel surface by the textile fabric under the specified pressure. In this process, the 10.16 cm x 10.16 cm (4 "x 4") specimens were fabricated using a dial comparator fitted with a 12.7 cm x 12.7 cm (5 "x 5") lucite platen. Measure The pressure applied due to the weight of the platen, the weight rod and the added weight is 182 ± 5 g (0.4 ± 0.01 lbs) (if a large specimen is not available, it can be replaced by a circular contact point of 2.54 cm (1 ") in diameter) In this case, the specimen diameter must be at least 2.54 cm (1 "). Measure the thickness of the specimen to the nearest 2.54 / 1000 cm (1/1000 inch). Five specimens from each sample are tested and their average calculated.

Air Permeability: The air permeability is a measure of the permeability of the fabric to air and is measured in air m ³ / fabric m ² / min (air ft ³ / fabric ft ² / min) through the fabric. During this test, the speed of air flowing through the textured area is adjusted to maintain different defined pressures between the two surfaces of the fabric at the test area. From this flow rate, the air permeability of the fabric is evaluated. The Textest FX-3300 Air Permeability Tester, available from Benninger Corporation (Spittenberg, CA), can be used to perform this test. In performing this test, specimens of approximately 20.32 cm x 20.32 cm (8 inches x 8 inches) will typically be used, but other sizes greater than 10.16 cm x 10.16 cm (4 inches x 4 inches) may be used. . The specimen is fixed to the test head of the transmittance tester and the vacuum pump is automatically activated. The air permeability of the test specimens will be expressed in the unit of measurement chosen (typically m ³ / fabric m ² / min (cubic feet / square foot / minute).

Cup grinding: The ductility of the nonwoven can be measured according to the "cup grinding" test. The cup milling test evaluates the peak load (also called "cup milling load" or just "cup milling") and energy units with a constant rate extension tensile tester to assess the stiffness of the fabric. Stiffer materials show higher peak load values. Peak load measurements include an inverted cup about 6.5 cm high and a cup-shaped fabric surrounded by a cylinder about 6.5 cm in diameter, with a piece of fabric about 23 cm x 23 cm shaped to about 6.5 cm in diameter, maintaining a constant cup-shaped deformation. A hemispherical foot with a diameter of 4.5 cm is required for grinding. The feet and cups can affect readings, so align the feet with the walls of the cups so that they do not come into contact.

The cup grinding test can also obtain the total energy value required to grind the sample (cup grinding energy "). The cup grinding energy is the energy from the start of the test to the peak load point, ie the load in g on one axis and on the other axis. The area under the curve formed by the travel distance of the foot in mm The cup milling energy is therefore reported in g / mm (or pounds per inch) A lower cup milling value indicates a softer nonwoven web.

A suitable device for measuring cup break is a constant speed extension tester, manufactured by Sintech Corporation of Cary, North Carolina. The machine used is one in which the rate of increase in test specimen length is uniform over time.

Drape: A "drape" of material refers to the stiffness of the fabric in the bending mode. A cantilever bending test is used to determine the bending length of a fabric using the cantilever bending principle of the fabric at its own weight. Bending length is a measure of the interaction between fabric weight and fabric stiffness as shown by how the fabric is bent at its own weight. During the test, all ten specimens of 2.54 cm by 20.32 cm (1 inch by 8 inches) slide 12.07 cm (4.75 inches) per minute in a direction parallel to their longitudinal direction, protruding edges from the edges of the horizontal surface. Cause. The length of the projections is measured at the end of the specimen at its own weight, with the line that meets the tip with respect to the edge of the platform at an angle of 41.5 ° with the horizontal platform. The longer the protrusion, the slower the test piece will bend, and thus a greater number of stiff fabrics will appear. The method used is in accordance with ASTM Standard Test D 1388, except that 2.54 cm x 30.32 cm (1 inch x 8 inches) is used instead of 2.54 cm x 15.24 cm (1 inch x 6 inches). The test uses a device such as the Cantilever Bending Tester, Model 79-10, from Testing Machines Inc. of Amityville, NY. If fabrics other than polypropylene-based materials are used, ASTM or TAPPI conditions should be used. In addition, five specimens should be cut in the longitudinal direction and five specimens should be cut in the transverse direction. The protrusion lengths of the various specimens are recorded from the linear scale of the tester. Longitudinal bending lengths and results reported as specimens shall be recorded separately from the transverse specimens. Drape stiffness is reported in cm and is the bending length divided by two.

Poison Ratio at 10% MD Elongation: “Poison Ratio at 10% MD Elongation” is a measure of the dimensional stability of a fabric. The lower the poison ratio, the better the dimensional stability of the fabric. In particular, the poison ratio is a measure of the change in width relative to the change in length. The better the dimensional stability of the fabric, the less likely the fabric will be "necked in" during the converting process. Poison ratio is a unitless number calculated by the following equation.

Ratio = [(W ₀ -W ₁ ) / W ₀ ] / [(L ₁ -L ₀ ) / L ₀ ]

Where

W ₀ is the initial sample width (typically 75 mm or 3 inches),

W ₁ is the sample width at extended length L ₁ ,

L ₀ is the initial sample length (typically 300 mm or 12 inches), the value of L ₀ is the minimum value four times greater than the W ₀ value,

L ₁ is the sample length at a given extension.

Syntec (or a similar device, such as an Instron machine) requires performing the tests described below.

1. If the jaw spacing is 300 mm or 12 inches, cut the sample length (L ₀ ) to a minimum of 38 cm (380 mm or 15 inches) with a sample width of 75 mm or 3 inches (W ₀ ). If different jaw spacings are used, the sample width should be no greater than 0.25 times the jaw spacing. The jaw face should be at least the width of the sample.

2. Draw a line along the center of the sample. Sample width is measured with an accuracy of 0.50 mm or 0.02 inches on this line.

3. Place the specimen specimen between the jaws on the syntech to minimize sagging or stretching of the specimen.

4. Measure and record the initial sample width (W ₀ ) with an accuracy of 0.50 mm or 0.02 inch. Initial sample width (or starting jaw spacing) is also recorded.

5. Manually extend the jaw spacing to increase sample length. Typically, this extends up to 10% or less in steps of 1% extension (ie, 300 mm to 303 mm; 303 mm to 306 mm; 306 mm to 309 mm, etc.).

6. Measure the sample width with the sample length (string spacing) extended to an accuracy of 0.50 mm or 0.02 inch in the first extension. This is repeated for all subsequent extensions.

Grab Tensile Test: The Grab Tensile Test is a measure of the breaking strength or elongation or strain of a fabric when under unidirectional stress. Such tests are known in the art and follow the instructions of Method 5100 of Federal Test Method Standard 191A. "Grap tensile peak load" is measured in kg and is the cutting load before rupture of the fabric when extending in a single direction, typically at a constant speed in the transverse direction (CD) of the fabric or in the longitudinal direction (MD) of the fabric. "Grap tensile peak strain" is a measure of the elongation of a fabric prior to rupture, i. . The term "elongation" or "strain" refers to the increase in the length of the specimen during the tensile test, expressed in percentage. Higher numbers indicate a stronger, more elongated fabric. The term "total energy" means the total energy expressed in weight-length units as the area under the curve of load versus elongation of the fabric. "Grap tensile peak energy" is the total energy just before it bursts.

The following is an example of a grab test. This grab test procedure is consistent with ASTM standards D-5034-92 and D-5035-92 and INDA 1ST 110.1-92 using a constant rate extension (CRE) tensile tester with a uniform specimen speed over time. Grab tests are performed under laboratory standard atmosphere of 23 ± 2 ° C (73.4 ± 3.6 ° F) and 50 ± 5% relative humidity (RH). In case of mismatch, the tolerances are ± 1 ° C (1.8 ° F) and ± 2% RH. In special cases, such as a control test where the conditioning requirements cannot be met and the data may still be a direct aid to operation, other conditioning procedures may be used if these alternative conditions are recorded. The material is measured only after sufficient time has elapsed for the specimen to reach its equilibrium with the surrounding atmosphere. Values for grab tensile strength and grab elongation are obtained at a specific width of the fabric, generally 102 mm (4 inches), clamp width and constant speed extension. The sample is wider than the clamp to provide a sample result of the effective fabric strength within the clamp width combined with the additional strength contributed by adjacent fibers in the fabric. Instron Model TM (Instron Corporation, Canton Washington Street 2500, 02021, USA) with an extension tester centered on a 100 mm (4 inch) wide specimen, e.g. a 76 mm (3 inch) parallel clamp. Or on the jaw of a Swing-Albert Model INTELLECT II (Thwing-Albert Insrtument Co., Duton Road 10960, Philadelphia, 19154, USA). This closely mimics fabric stress conditions in practical use. Apply force until the specimen is cut. Values for cutting force and elongation of the test specimen are obtained from a machine scale, a dial, a magnetic recording chart, or a computer interfaced with the tester. The grab test procedure measures the effective strength of a fabric, that is, the strength of a fiber of a particular width with fabric assistance from adjacent fibers. The cutting force measured by the grab procedure is not a reflection of the strength of the fiber substantially held between the jaw faces and cannot be used for direct comparison with the fiber strength measurement. In addition, there is no simple correlation between grab test and strip test because the amount of fiber aid depends on the type of fabric and the structural variables.

"Strip tensile peak load" is the cutting load before the fabric strip ruptures in a constant speed extension in one direction, typically the transverse (CD) or longitudinal (MD) direction of the fabric. A "strip tensile peak strain" is a measure of the elongation of the fabric strip prior to rupture, ie, the "stretch" of the fabric strip in a constant velocity extension in one direction, typically the transverse (CD) or longitudinal (MD) direction of the fabric. The following is an example of a strip test. Mount the jaw of the tensile tester around a 100 mm (4 inch) wide specimen and apply force until the specimen is cut. Values for cutting force and elongation of the test specimen are obtained from a machine scale, dial, magnetic recording chart, or computer interfaced with the tester. The strip test procedure measures the effective strength of a fabric, that is, the strength of a fiber of a certain width with the fabric aid from adjacent fibers.

Typical disposable personal care absorbent articles include liquid permeable bodyside liners. For example, as shown in FIG. 6, the diaper 60 includes a liquid permeable bodyside liner 64. Various nonwovens of the present invention can be used in the bodyside liner or sheath 64. For example, the web constituting the bodyside liner may be a meltblown or spunbond nonwoven web of synthetic fibers, such as thermoplastic fibers such as polyolefin fibers, such as melt-spun filaments, staple fibers, melt-spun multicomponent filaments Can be done.

Fibers can be formed from various thermoplastic polymers, meaning the long-chain polymers that soften when the term “thermoplastic polymer” is exposed to heat and return to their original state when cooled to ambient temperature. Examples of thermoplastics include poly (vinyl) chloride, polyesters, polyamides, polyfluorocarbons, polyolefins, polyurethanes, polystyrenes, poly (vinyl) alcohols, caprolactam and copolymers of these materials, and elastomeric polymers such as Elastic polyolefins, copolyether esters, polyamide polyether block copolymers, ethylene vinyl acetate (EVA), block copolymers having the formula ABA 'or AB, for example copoly (styrene / ethylene-butylene), styrene Poly (ethylene-propylene) -styrene, styrene-poly (ethylene-butylene) -styrene, (polystyrene / poly (ethylene-butylene) / polystyrene, poly (styrene / ethylene-butylene / styrene), ABAB tetrablock Copolymers and the like, but are not limited thereto.

The fibers or filaments used to prepare the nonwovens may be in any suitable form and may be hollow or solid, straight or crimped, monocomponent, composite or bicomponent fibers or filaments, as is well known in the art. And blends or mixtures of such fibers and / or filaments. All such nonwoven webs are prebonded or integrated using known nonwoven web bonding techniques, such as hot air knives, compression rolls, aeration bonding, ultrasonic bonding and stitching bonding, and bonded using the methods and apparatus of the present invention. Alternatively, such nonwoven webs may be glued using only the methods and apparatus of the present invention.

Many polyolefins are used to make fibers, such suitable polymers include, for example, polyethylene, such as PE XU 61800.41 linear low density polyethylene ("LLDPE") from Dow Chemical and 25355 and 12350 high density polyethylene ("HDPE"). Can be mentioned. Fiber-forming polypropylenes include Escorne® PD 3445 polypropylene from Exxon Chemical Company and PF-304 and PF-015 from Montel Chemical Co. Many other conventional polyolefins can be used commercially, including polybutylene and the like.

Examples of polyamides and methods of their synthesis can be found in "Polymer Resins", Don E. Floyd (Library of Congress Catalog No. 66-20811, Reinhold Publishing, New York, 1966). Particularly useful polyamides are nylon-6, nylon 6,6, nylon-11 and nylon-12. Such polyamides include Emser Industries (Grilon® and Grilamid® Nylon), Sumter, South Carolina, Atochem Inc., Glen Rock, NJ. Atochem Inc. Polymers Division (Rilsan® Nylon), Nyltech (2169, Nylon 6), Manchester, New Hampshire, and Custom Resin (Henderson, Kentucky) Custom Resins) [Nylene 401-D] are commercially available in numerous places.

Useful elastomer resins include thermoplastic polymer endblocks containing styrene-based moieties such as formula ABA 'or AB, where A and A' are each poly (vinyl arene), and B is an elastomer polymer intermediate such as conjugated diene or lower alkene polymer. Block copolymers). Block copolymers of A and A 'blocks and block copolymers of the present invention include linear, branched and radial block copolymers. The radial block copolymers can then be represented by (AB) _m -X, where X is a multifunctional atom or molecule, and each (AB) _m -is emitted from X in such a way that A is endblocked. In radial block copolymers, X can be an organic or inorganic polyfunctional atom or molecule, and m is an integer of the same number as the functional group originally present in X. Typically 3 or more, preferably 4 or 5, but is not limited thereto. Thus, the expressions "block copolymer" and "ABA" and "AB" block copolymer in the present invention are not limited to the number of blocks, as discussed above, which can be extruded (eg by meltblowing). All block copolymers having such rubbery blocks and thermoplastic blocks are included. Elastomeric nonwoven webs can be formed, for example, from elastomer (polystyrene / poly (ethylene-butylene) / polystyrene) block copolymers. Commercial examples of such elastomeric copolymers are known, for example, as KRATON® materials sold by Shell Chemical Company, Houston, Texas. Kraton® block copolymers are commercially available in several different compositions, most of which are described in US Pat. Nos. 4,663,220, 4,323,534, 4,834,738, 5,093,422, and 5,304,599. have.

In addition, polymers composed of elastomer A-B-A-B tetrablock copolymers can be used in the practice of the present invention. Such polymers are discussed in US Pat. No. 5,332,613 to Taylor et al. In such polymers, A is a thermoplastic polymer block and B is an isoprene monomer unit substantially hydrogenated to a poly (ethylenepropylene) monomer unit. Examples of such tetrablock copolymers are styrene-poly (ethylene-propylene) -styrene-poly (ethylene-propylene) sold by Shell Chemical Company of Houston, Texas, under the trade name Kraton G-1657. Or SEPSEP elastomer block copolymer.

Examples of other elastomeric materials that can be used include polyurethane elastomeric materials, such as B.F. Polyester elastomer materials such as trade name ESTAN (ESTANE®) or Morton Thiokol Corp. (MORTHANE®), a polyester elastomer material sold by BF Goodrich & Co. Listen to this. HYTREL®, available from EI DuPont De Nemours & Company, and Akzo Plastics, Amhem, The Netherlands, but now in Citad, The Netherlands And those known as ARNITEL®, which are commercially available from DSM.

Other suitable materials are Polyester block amide copolymer, wherein n is a positive integer, PA is a polyamide polymer segment and PE is a polyether polymer segment. In particular, the polyether block amide copolymer has a melting point of about 150 ° C. to about 170 ° C., measured according to ASTM D-789, and a melt index of 10 ° C. according to ASTM D-1238, Condition Q (235 C / 1 kg dropping). From about 6 g to about 25 g per minute, a flexural modulus of about 20 MPa to about 200 MPa as measured according to ASTM D-790, a cut tensile strength of about 29 MPa to about 33 MPa as measured according to ASTM D-638, Cutting ultimate elongation measured according to ASTM D-638 is from about 500% to about 700%. Certain embodiments of the polyether block amide copolymers have a melting point, measured according to ASTM D-789, of about 152 ° C., a melt index as measured in accordance with ASTM D-1238, Condition Q (235 C / 1 kg dropping) per 10 minutes. About 7 g, flexural modulus measured according to ASTM D-790 is about 29.50 MPa, cut tensile strength measured according to ASTM D-639 about 29 MPa, cut ultimate elongation measured according to ASTM D-638 %to be. Such materials are available in a variety of grades under the PEBAX® trade name from ELF Atochem Inc., Glen Rock, NJ. Examples of the use of such polymers can be found in Killian US Pat. Nos. 4,724,184, 4,820,572 and 4,923,742.

Elastomeric polymers also include copolymers of ethylene and one or more vinyl monomers such as vinyl acetate, unsaturated aliphatic monocarboxylic acids, and esters of such monocarboxylic acids. Elastomeric copolymers and the formation of elastomeric nonwoven webs from such elastomeric copolymers are described, for example, in US Pat. No. 4,803,117.

Thermoplastic copolyester elastomers include Wherein G is poly (oxyethylene) -α, ω-diol, poly (oxypropylene) -α, ω-diol, poly (oxytetramethylene) -α, ω-diol, and a and b are 2, 4 And a positive integer comprising 6, and m and n are positive integers including 1 to 20). Such materials typically have a cut elongation of about 600% to 750% as measured according to ASTM D-638 and a melting point of about 176 to about 205 ° C (about 350 ° F to about 400 ° F) as measured according to ASTM D-2117. .

Industrial examples of such copolyester materials are for example known as Arnitel®, commercially available from Akzo Plastics, Amhem, the Netherlands but now commercially available from DSM, Citad, The Netherlands, or Delaware. Hytrel (R), which is commercially available from E.I Dupont de Nemoir & Company, Wilmington, USA. The formation of elastomeric nonwoven webs from polyester elastomeric materials is described, for example, in US Pat. No. 4,741,949 to Morman et al. And US Pat. No. 4,707,398 to Boggs.

Elastomeric olefin polymers are manufactured from Exxon Chemical Company, Baytown, Texas under the trade name ACHIEVE® as a polypropylene based polymer and under the trade names EXACT® and EXCEED® as polyethylene based polymers. It is commercially available. Dow Chemical Company, Midland, Mich., Markets polymers under the trademark ENGAGE®. These materials are thought to be prepared using non-stereoselective metallocene catalysts. Exon commonly refers to its metallocene catalyst technology as a "single site" catalyst, and Dow uses the "INSIGHT® tradename" to distinguish them from conventional Ziegler-Natta catalysts with multiple reaction sites. "Constrained geometry" is called a catalyst.

According to embodiments of the present invention, the ultralight fabric may be formed from a nonwoven web having a fibrous structure of individual fibers or filaments. The nonwoven webs of the present invention, which are pattern unbonded and pattern bonded fabrics, will be ultralight fabrics that exhibit better relative dimensional stability compared to similar weight fabrics not manufactured in accordance with the present invention. In particular, the fabric of the present invention has a basis weight of about 13.56 g / m ² (about 0.40 osy) or less. More specifically, the fabric will have a basis weight of about 10.17 g / m ² (about 0.30 osy) or less. In addition, the fabric may have a basis weight of about 6.78 g / m ² (about 0.20 osy) or less. The minimum basis weight of the fabric of the invention will depend on the particular use of the material from which the fabric is made. For example, any lightweight fabric having characteristics of the present invention may fall within the scope of the present invention, but webs with a basis weight as low as 3.39 g / m ² (0.10 osy) may be used in the present invention. The bonded area of the present invention, whether pattern unbonded or pattern bonded fabric, will be 50% or less of the total bonded area. More specifically, the bonding area of the web of the present invention will be 40% or less of the total bonding area. Even more specifically, the junction area will be no greater than 30% of the total junction area and can be about 15% of the total junction area. Typically, depending on the particular properties desired in the final product, even if other bond areas are within the scope of the present invention, a minimum bond area of at least about 10% is acceptable for producing the ultralight fabric-like web of the present invention. Typically, the lower limit of the bonding area% suitable for forming the ultralight nonwoven of the present invention is the point at which the surface integrity and durability of the material is drastically reduced due to fiber pulling. The percent bonded area required will be influenced by a number of factors, including the type (s) of the polymeric material used to form the fibers or filaments of the nonwoven web, whether the nonwoven web is single or multimodal fiber structure or the like. Bonding regions ranging from about 15% to about 50%, more specifically from about 15% to about 40%, have been found to be suitable.

Various methods can be used to bond the web of the present invention. Such methods include vent junctions and hot spot junctions as described in US Pat. No. 3,855,046 to Hansen et al., Which is incorporated by reference in its entirety herein. It is also possible in certain cases to use other bonding means, such as ovenbonding, ultrasonic bonding, hydroentanglement, or a combination thereof.

As shown in FIGS. 1 and 2, one particular fabric of the present invention is a patterned non-bonded fabric 4 in which the continuous bonded area 6 defines a number of individual dimensionally stable non-bonded areas 8 in the nonwoven fabric 4. Can be prepared.

As further exemplified herein, a method suitable for making the patterned non-bonded nonwoven of the present invention provides a nonwoven or nonwoven web, provides opposed first and second calendar rolls, and a gap therebetween. Along with the defining step, heating one or more of the rolls having a bonding pattern on a top surface comprising a continuous pattern of land areas defining a plurality of individual openings, perforations or holes. Each opening of the roll (s) defined by the continuous flat forms an individual non-bonded region on at least one surface of the nonwoven or nonwoven web, wherein the fibers or filaments of the web are not substantially or completely bonded. In other words, the flat portions of the continuous pattern in the roll (s) form a continuous pattern of bonded areas defining a plurality of individual non-bonded areas on at least one surface of the nonwoven or nonwoven web. Another embodiment of the method provides for prebonding or incorporating a nonwoven or nonwoven web prior to passing the fabric or web through a gap formed by a calendar roll, or providing multiple nonwoven webs to form a patterned non-bonded laminate. It involves doing. Patterned non-bonded fabrics are commonly disclosed in assigned US patent application Ser. No. 08 / 754,419 and shown in FIGS. 1 and 2, wherein the continuous bonded area 6 is a plurality of individual dimensionally stable non-bonded areas in the nonwoven fabric 4. (8) is limited.

Referring now to FIGS. 4 and 5, one exemplary method and apparatus for forming the patterned non-bonded nonwoven of the present invention will be described in detail. In FIG. 4, the apparatus for forming the patterned non-bonded nonwoven of the present invention is generally indicated by the numeral 34. The device 34 can include a first web solving device 36 and a patterned unbonded assembly 40. As shown in FIG. 4, a web 38 of ultralight material having a basis weight of less than 13.56 g / m ² (0.40 oz / yard ² ), for example, is detached from the decoupling device 36 and the first or pattern roll 42 And a second or anvil roll 44 (both driven by conventional drive means, for example an electric motor (not shown)). Additional fabric unwinding devices (not shown) can be used if one wishes to build a multilayer stack according to the invention. It will also be appreciated that the nonwoven can be fed directly from the machine forming the fabric itself instead of being unwound from the roll.

The pattern roll 42 is a staff post, which can be made of any suitable durable material, for example steel, which reduces wear on the roll in use. The pattern roll 42 has a pattern of flats 46 that define a number of individual openings or perforations 48 on its top surface. The flats 46 are also designed to form gaps 50 with staff columns and opposingly positioned smooth or flat outer surface anvil rolls 44 that can be made of any suitable durable material.

As shown in FIG. 4, the ultralight nonwoven or nonwoven web 38 passes through the gap 50 formed by the rolls 42, 44. Each opening 48 in the roll (s) 42 defined by the continuous flats 46 is substantially free of fibers or filaments of the web on at least one surface of the nonwoven or nonwoven web 4 (FIGS. 1 and 2). Individual non-bonded regions 8 (FIGS. 1 and 2) are not fully bonded. In other words, the flat portion 46 of the continuous pattern in the roll (s) 42 defines a number of individual non-bonded regions 8 (FIGS. 1 and 2) on at least one surface of the nonwoven or nonwoven web 4. The junction region 6 (FIGS. 1 and 2) of the continuous pattern is formed.

As shown in FIG. 5, in making the patterned non-bonded nonwoven 4 of the present invention, the average diameter of the opening 48 is from about 0.127 cm (about 0.050 inch) to about 0.635 cm (about 0.250 inch), more Specifically about 0.330 cm (about 0.100 inch) to about 0.406 cm (about 0.160 inch), the depth measured from the outermost surface of the pattern roll 42 is about 0.051 cm (about 0.020 inch) or more, more specifically about 0.152 cm (About 0.060 inches) or more. In addition, although the openings 48 in the pattern roll 42 as shown in FIG. 5 are circular, other forms such as ellipses, squares, diamonds and the like may be advantageously used.

The number or density of openings 48 in the pattern roll 42 may also be selected to provide the requisite dimensional stability to the ultralight fabric. Pattern rolls having a range of aperture densities from about 1.0 to about 25.0 per cm 2, more specifically from about 5.0 to about 7.0 apertures per cm 2, can be used to form the patterned non-bonded fabric 4 of the present invention. . In addition, the spacing between the individual openings 48 may be selected from about 3.30 mm (about 0.13 inches) to about 5.59 mm (about 0.22 inches) with a centerline to centerline in the longitudinal and transverse directions.

The particular arrangement or shape of the openings 48 in the pattern roll 42 is chosen to achieve the desired degree of dimensional stability along with the opening size, shape and density. For example, as shown in FIG. 5, each opening 48 is arranged in a wavy row (also shown in FIG. 1). Other different shapes are also considered to be within the scope of the present invention.

Likewise, the outermost portion of the patterned roll 42 occupied by the continuous flats 46 can be modified to meet the expected end use of the patterned non-bonded material. The degree of bonding imparted to the patterned non-bonded ultralight nonwoven by the continuous flats 46 can be expressed in percent bonded area, which is the patterned non-woven nonwoven 4 occupied by the bonded area 6 (see FIG. 1). Is the ratio of the total planar area of at least one surface.

The temperature of the outer surface of the pattern roll 42 can be changed by heating or cooling compared with the anvil roll 44. Heating and / or cooling affects the characteristics of the web (s) being processed and the degree of bonding of the single or multiple webs through the gap formed between the reverse rotation pattern roll 42 and the anvil roll 42. In the embodiment shown in FIG. 4, for example, both the pattern roll 42 and the anvil roll 44 are preferably heated to the same bonding temperature. The specific temperature range used in the formation of the patterned non-bonded nonwoven as described above is the type of polymeric material used in the formation of the patterned non-bonded material, the nonwoven passing through the gap formed between the pattern roll 42 and the anvil roll 44. It depends on a number of factors including the inflow or linear velocity (s) of the web (s) and the gap pressure between the pattern roll 42 and the anvil roll 44.

The anvil roll 42 as shown in FIG. 4 is much smoother than the pattern roll 42 and preferably has a smooth or flat outer surface.

However, the anvil roll 44 may have some pattern on its outer surface which is still considered smooth or flat for the purposes of the present invention. Such surfaces are collectively referred to as "flat". Anvil roll 44 provides a basis for pattern roll 42 and the web (s) of material in contact with it. Typically, pattern roll 42 and anvil roll 44 will be made of steel.

Anvil roll 44 may also be replaced with a pattern roll (not shown) having a pattern of continuous flats that define a number of individual perforations or openings therein, such as in pattern roll 42 as described above. In this case, the pattern unbonded assembly includes a pair of reverse rotation pattern rolls, which impose a continuous bond region that defines a number of individual non-bonded regions on the top and bottom surfaces of the pattern unbonded nonwoven. The rotation of the oppositely positioned pattern rolls can be matched such that the non-bonded regions created on the surface of the patterned non-bonded material are arranged in a vertical row or in parallel.

Referring again to FIG. 4, the pattern roll 42 and the anvil roll 44 rotate in opposite directions so that the ultralight nonwoven web 38 passes through the gap region defined therebetween. The pattern roll 42 has a first rotational speed measured at its outer surface, and the anvil roll 44 has a second rotational speed measured at its outer surface. In the embodiment shown, the first and second rotational speeds are substantially the same. However, the rotational speed of the pattern and the anvil roll can be modified so that different speeds are produced between the reverse rolling rolls.

As shown in another embodiment shown in FIG. 3, the ultralight fabric 5 has a number of individual dimensionally stable point bonding regions 9 (dark portions) in the nonwoven fabric 5 where the continuous bonding regions 7 (not dark portions) are formed. It is provided in the form of point bonded ultralight fabrics. The fabric 5 is made from a nonwoven web having a fiber structure of each fiber or filament.

The nonwoven web is an ultralight fabric (5) and has a basis weight of less than 13.56 g / m ² (0.40 osy). The pattern of the point junction region 9 includes the rectangle shown in FIG. 3 in which the density of the point junction region 9 with respect to the non-junction region 7 is not scaled to explain the density of the point junction region 9. It can be formed in various shapes. Showing the point junction regions 9 on a scale for the high density of the present invention will make the point junction regions 9 cluster together so that it is difficult to distinguish the continuous non-bonded regions 7 therebetween.

In forming the discontinuous bonding pattern of the present invention, the fabric or web of fibers to be joined passes between the heated calendar roll and the anvil roll. Callander rolls are patterned in several ways to prevent areas of the fabric from joining, and anvil rolls are generally flat.

As in the embodiment of the pattern unbonded of the fabric (4), the fabric (5) is characterized by a coefficient calculated by multiplying the nonwoven web poison ratio at the 10% longitudinal elongation by the basis weight of the nonwoven web, which coefficient is 40.69 g / m ² (1.20 osy) · PR value or less has a dimensional stability.

In another embodiment of the present invention, the aforementioned ultralight fabrics can be used to form liquid permeable bodyside liners 64 for personal care products, such as diaper 60 (shown in FIG. 6). In the diaper embodiment shown in FIG. 6, for example, an absorbent core 66 formed of a blend of hydrophilic cellulose wood pulp fluff fibers with superabsorbent gelling particles (eg, superabsorbent) is formed with a liner 64 and an exterior. Disposed between the cover 62. The elastic member may be disposed adjacent each longitudinal edge 68 of the diaper 60 to pull and hold the side margins 68 of the diaper 60 against the wearer's legs. In addition, the elastic member may be disposed adjacent to either or both of the distal edges 70 of the diaper 60 to provide an elasticized waistband. The diaper 60 may further include any containment flap 72 attached to or formed from the bodyside liner 64. Suitable structures and arrangements for such containment flaps are described, for example, in US Pat. No. 4,704,116 to Enloe, which is incorporated herein by reference in its entirety. The means for securing the diaper 60 around the wearer is a hook member 74 attached to the inner and / or outer surface of the outer cover 62 in the back waistband region of the diaper 60 and the front waist of the diaper 60. It may be a hook and loop fastening system comprising one or more loop members or patches 76 made of patterned unbonded loop material attached to the outer surface of the outer cover 62 of the band region.

Referring to the table below, "PU" stands for patterned non-bonded fabric and "DB" stands for discontinuous bonded fabric. The control samples in the series of "Table A" (all discontinuous bonded fabrics) have the following bonding pattern:

Control number 1 15-20% junction area 48.3 pins / cm 2 (302 pins / inch ² )

Control number 2 9-20% junction area 16.3 pins / cm 2 (102 pins / inch ² )

Control number 3 15-20% junction area 48.3 pins / cm 2 (302 pins / inch ² )

Pitesa control 18% junction area 32.6 pins / cm 2 (204 pins / inch ² )

Cami control 18% junction area 32.6 fins / cm 2 (204 fins / inch ² )

Polybond Control 18% Bonding Area 32.6 pins / cm 2 (204 pins / inch ² )

The fabric of Control No. 1 is a spunbond reticulated pattern. The fabric of reference number 2 is a delta dot pattern. The fabric of reference number 3 is a reticular pattern. The other three counterparts are commercially available fabrics available from named companies (Fitessa, KAMI and Polybond).

With reference to the following tables, the samples of the present invention, denoted as "discontinuous bonded fabrics of the present invention" in the following series of "Table B", have a bond density in which the bonding area is in the range of 15% to 18% but very closely spaced apart from each other. Has a dense diamond pattern with 71.8 fins / cm 2 (460 fins / inch ² ). The pin lateral dimension in this pattern is 0.046 cm (0.018 inches). In the case of alternating rows, the pin-to-pin distance (center to center) in the transverse direction is 0.218 cm (0.086 inches) and measured in the same row, and 0.127 cm (0.050 inches) in the longitudinal direction. )to be. The junction depth is 0.061 cm (0.024 inches) in this pattern. This fabric illustrates the pattern bonded fabric of the present invention. Samples labeled with patterned non-bonded fabrics of the present invention illustrate the patterned non-bonded fabrics of the present invention.

The control fabrics listed above and the polymers used in the fabrics of the invention (discontinuous bonds and pattern unbonded) are described as follows:

Control number 1 PP (polypropylene) 35 MFR

Union Carbide E5D47 with 2% TiO ₂

Control No. 2 PP 35 MFR Union Carbide E5D47 with 2% TiO ₂

Control number 3 PP 35 MFR exon 3445 with 2% TiO ₂

Discontinuous Bonding Fabric PP 35 MFR Union Carbide E5D47 (Contains 2% TiO ₂ ) of the Invention

Pattern non-bonded PP 35 MFR exon 3445 of the present invention (containing 2% TiO ₂ )

Fabric number 1 (samples 10, 11, 12, 13, 15, 16, 18, 19, 20, 21)

Pattern non-bonded PP 35 MFR exon 3445 of the present invention (containing 2% TiO ₂ )

Fabric number 2 (samples 9, 14, 17)

Contrasting fabric Contrasting fabric Basis weight (g / ㎡ (oz / yd ² )) Denier (dpf) 12.7 cm (5 ") bulk drying (cm (inch)) Air permeability (㎥ / ㎡ / min (ft ³ / ft ² / min)) Cup grinding load (g) Control number 1 18.62 (0.549) 2.20 0.036 (0.014) 321 (1053) 29 Control number 2 10.17 (0.30) 1.86 0.023 (0.009) 428 (1404) 10 Control number 3 13.56 (0.40) 1.82 0.025 (0.010) 325 (1065) 26 Pitesa counterpart 16.28 (0.48) 2.53 0.028 (0.011) 301 (987) 27 Cami counterpart 9.83 (0.29) 2.9 0.020 (0.008) 474 (1556) 17 Polybond Control 17.29 (0.51) 2.98 0.033 (0.013) 336 (1101) 14

Discontinuous Bonding Fabric of the Invention Pattern Bonding Sample Basis weight (g / ㎡ (oz / yd ² )) Denier (dpf) 12.7 cm (5 ") bulk drying (cm (inch)) Air permeability (㎥ / ㎡ / min (ft ³ / ft ² / min)) Cup grinding load (g) One 14.92 (0.44) 1.10 0.015 (0.006) 178 (584) 58 2 11.19 (0.33) 1.10 0.015 (0.006) 263 (862) 30 3 7.80 (0.23) 1.10 0.007 (0.003) 357 (1170) 19 4 5.43 (0.16) 1.10 0.010 (0.004) 482 (1580) 12 5 6.10 (0.18) 1.40 0.010 (0.004) Do not measure 13 6 7.12 (0.21) 1.40 0.010 (0.004) 447 (1468) 16 7 10.51 (0.31) 1.40 0.015 (0.006) 305 (1001) 22 8 14.24 (0.42) 1.40 0.018 (0.007) 235 (772) 39

Discontinuous Bonding Fabric Nos. 1 and 2 of the Invention Pattern Bonding Sample Basis weight (g / ㎡ (oz / yd ² )) Denier (dpf) 12.7 cm (5 ") bulk drying (cm (inch)) Air permeability (㎥ / ㎡ / min (ft ³ / ft ² / min)) Cup grinding load (g) 9 4.04 (0.119) 1.23 0.010 (0.004) Do not measure 3 10 6.41 (0.189) 2.10 0.015 (0.006) Do not measure 8 11 7.22 (0.213) 3.90 0.015 (0.006) Do not measure 9 12 7.83 (0.231) 2.10 0.015 (0.006) 473 (1553) 14 13 10.60 (0.271) 2.10 0.015 (0.006) 394 (1292) 19 14 9.53 (0.281) 1.23 0.015 (0.006) 241 (791) 15 15 9.56 (0.282) 3.90 0.018 (0.007) Do not measure 14 16 13.06 (0.385) 2.10 0.020 (0.008) 279 (916) 32 17 16.82 (0.496) 1.23 0.023 (0.009) 109 (359) 56 18 18.45 (0.544) 2.10 0.031 (0.012) 185 (607) 65 19 19.16 (0.565) 3.90 0.028 (0.011) 276 (904) 58 20 20.11 (0.593) 3.90 0.033 (0.013) 277 (909) 57 21 20.99 (0.619) 5.60 0.033 (0.013) 325 (1065) 59

Contrasting fabric Contrasting fabric Cup grinding energy (g / mm) Drape CD (cm) Drape MD (cm) Poison Ratio at 10% MD Elongation Grab Tensile Peak Load (kg (lbs)) CD Control number 1 474 1.62 2.89 3.49 2.18 (4.8) Control number 2 84 1.09 1.40 4.10 1.45 (3.19) Control number 3 435 1.73 1.99 3.32 3.1 (6.87) Pitesa counterpart 453 1.60 2.00 4.82 2.77 (6.1) Cami counterpart 150 1.18 1.53 4.19 1.32 (2.9) Polybond Control 179 1.47 1.23 2.87 2.95 (6.5)

Discontinuous Bonding Fabric of the Invention Pattern Bonding Sample Cup grinding energy (g / mm) Drape CD (cm) Drape MD (cm) Poison Ratio at 10% MD Elongation Grab Tension Peak Load (kg (lbs)) CD One 909 2.12 2.77 2.82 2.21 (4.88) 2 347 1.58 2.59 3.18 1.32 (2.92) 3 114 1.38 2.13 3.81 0.83 (1.82) 4 Do not measure 1.44 1.82 4.15 0.40 (0.88) 5 Do not measure 1.82 2.19 4.13 0.45 (1.00) 6 53 1.56 1.91 4.04 0.65 (1.44) 7 216 1.44 1.98 3.36 1.06 (2.34) 8 522 2.22 2.25 2.72 1.88 (4.15)

Pattern non-bonded fabric numbers 1 and 2 of the present invention Pattern Unbonded Sample Cup grinding energy (g / mm) Drape CD (cm) Drape MD (cm) Poison Ratio at 10% MD Elongation Grab Tension Peak Load (kg (lbs)) CD 9 48 1.00 1.79 4.47 0.45 (1.0) 10 149 1.38 1.73 4.26 1.04 (2.3) 11 152 1.47 1.83 4.34 0.23 (0.5) 12 233 1.31 2.05 3.75 1.41 (3.1) 13 344 1.45 2.23 3.61 1.45 (3.2) 14 282 1.37 2.30 3.29 1.22 (2.7) 15 279 1.64 2.30 4.04 0.77 (1.7) 16 591 2.47 2.47 3.08 1.80 (3.9) 17 1049 1.93 2.61 2.49 2.68 (5.9) 18 1238 1.89 3.02 2.53 3.22 (7.1) 19 1126 1.73 2.94 3.05 2.59 (5.7) 20 1104 2.11 2.61 2.83 2.36 (5.2) 21 1066 2.15 2.33 3.05 1.63 (3.6)

Contrasting fabric Contrasting fabric Grab Tensile Peak Strain (%) CD Grab Tension Peak Energy CD Grab Tension Peak Load (kg (lbs)) MD Grab Tensile Peak Strain (%) MD Control number 1 79.1 5.7 3.36 (7.4) 45.3 Control number 2 120.96 5.77 2.54 (5.59) 74.68 Control number 3 76.84 9.42 4.09 (9.02) 68.01 Pitesa counterpart 59.7 2.95 (6.5) 28.2 Cami counterpart 44.1 2.81 (6.2) 34.8 Polybond counterparts 80.4 4.76 (10.5) 70.9

Discontinuous Bonding Fabric of the Invention Pattern Bonding Sample Grab Tensile Peak Strain (%) CD Grab Tension Peak Energy CD Grab Tension Peak Load (kg (lbs)) MD Grab Tensile Peak Strain (%) MD One 36.06 2.98 3.01 (6.63) 22.19 2 33.87 1.64 1.65 (3.64) 16.07 3 36.38 1.07 0.93 (2.05) 13.07 4 31.85 0.44 0.68 (1.50) 16.83 5 52.56 0.79 0.73 (1.60) 12.38 6 27.45 0.65 0.68 (1.50) 12.36 7 28.59 1.10 1.27 (2.79) 14.95 8 32.02 2.25 1.78 (3.93) 15.54

Pattern non-bonded fabric numbers 1 and 2 of the present invention Pattern Unbonded Sample Grab Tensile Peak Strain (%) CD Grab Tension Peak Energy CD Grab Tension Peak Load (kg (lbs)) MD Grab Tensile Peak Strain (%) MD 9 58.2 0.9 0.91 (2.0) 28.6 10 66.9 3.2 1.54 (3.4) 29.6 11 74.7 0.7 0.86 (1.9) 64.5 12 56.5 2.6 2.00 (4.4) 32.9 13 40.7 2.1 2.00 (4.4) 27.0 14 34.3 1.6 2.63 (5.8) 28.3 15 69.0 2.4 1.59 (3.5) 44.6 16 32.5 2.0 3.18 (7.0) 29.9 17 28.7 3.0 4.94 (10.9) 25.5 18 39.8 4.5 4.67 (10.3) 24.7 19 44.3 4.3 4.17 (9.2) 30.2 20 66.6 7.1 4.17 (9.2) 35.1 21 63.8 5.1 3.22 (7.1) 34.2

Contrasting fabric Contrasting fabric Grab Tensile Peak Energy MD Strip Tension Peak Load (kg (lbs)) CD Strip Tensile Peak Stress (%) CD Control number 1 6.1 Control number 2 7.45 1.19 (2.63) 92.53 Control number 3 11.17 2.63 (5.79) 45.93 Pitesa counterpart Cami counterpart Polybond counterparts 1.13 (2.5) 89.8

Discontinuous Bonding Fabric of the Invention Pattern Bonding Sample Grab Tensile Peak Energy MD Strip Tension Peak Load (kg (lbs)) CD Strip Tensile Peak Stress (%) CD One 2.75 2.47 (5.45) 30.25 2 1.08 1.66 (3.65) 29.58 3 0.51 0.89 (1.97) 27.82 4 0.47 0.58 (1.27) 28.50 5 0.37 0.41 (0.90) 41.51 6 0.35 0.84 (1.85) 20.85 7 0.77 1.43 (3.16) 23.35 8 1.12 2.06 (4.55) 23.20

Invention Pattern Non-bonded Fabric No. 1 and 2 Non-patterned sample Grab Tensile Peak Energy MD 9 1.1 10 1.7 11 2.5 12 2.6 13 1.9 14 3.0 15 3.3 16 3.5 17 5.1 18 4.7 19 5.2 20 6.0 21 4.7

7 to 11 show the data in the table in graphical form. In accordance with the present invention, the poison ratios of both the pattern conjugated ultralight material (5) shown in Table II-B and the pattern non-bonded material (4) (FIGS. 1 and 2) shown in Table II-C were compared to the control shown in Table II-A. Lower than water Poison ratios are low over a range of basis weights for all fiber deniers. Thus, the fabric of the present invention has better dimensional stability than the control fabric. The table shows the effect of denier on the poison ratio. Even when the fabric of the present invention has a large denier, the fabric of the present invention outperforms the control of similar basis weight.

In general, for typical fabrics, if the basis weight of the fabric decreases at a constant denier per filament, the poison ratio will increase. This increase is expected because of less fiber per unit area of fabric. In general, for typical fabrics, if the denier per filament decreases at a constant basis weight, the poison ratio will also decrease. This will occur because there are more fibers per unit area. One way to correct poor poisoning ratio at a fixed basis weight would be to lower denier per filament. However, in some cases, lowering the denier per filament is not useful for web designers because other factors are controlled by the denier. For example, a reduction in denier may also be unsatisfactory for certain applications, such as the sheathing of liner or absorbent wiping laminates of personal care products, where permeability or porosity is reduced, resulting in better liquid intake goals at higher permeability. Surprisingly, the fabrics of the present invention having a greater denier per filament outperform the control fabrics at the same basis weight, even if the control has less denier per filament than the fabric of the present invention. From this fact it is concluded that the fabrics of the invention not only provide improved dimensional stability at low basis weights, but also that the fabrics of the invention also outperform the control fabrics with lower denier per filament with the best dimensional stability.

Table V below summarizes the results of the poison ratios of various fabrics having a basis weight of less than 13.56 g / m ² (0.40 osy). The fabric obtained the following data is a fabric that exhibits the lowest poison ratio at a particular bonding temperature. The junction temperature, where only one temperature is listed, is the surface temperature of both the pattern and the anvil roll, and if both temperatures are listed, the first number is the temperature of the pattern roll surface and the second number represents the temperature of the anvil roll surface. Table V also shows the results obtained by multiplying the poison ratio by the basis weight of the fabric. The entries in Table V are arranged in increasing order of these coefficients.

Web sample (PU or DB) Basis weight (g / m ² (oz / yd ² )) Denier (dpf) Poison Ratio at 10% MD Elongation (Poison Ratio) x (Basic Weight) (g / m ² (osy), PR) Junction temperature (℃ (℉)) 9 (PU) 4.035 (0.119) 1.23 4.47 17.97 (0.53) 140.6 (285) 4 (DB) 5.324 (0.157) 1.10 4.15 22.04 (0.65) 142.8 / 141.1 (289/286) 5 (DB) 6.138 (0.181) 1.40 4.13 25.43 (0.75) 142.8 / 141.1 (289/286) 10 (PU) 6.409 (0.189) 2.10 4.26 27.13 (0.80) 143.3 (290) 6 (DB) 7.189 (0.212) 1.40 4.04 29.16 (0.86) 142.8 / 141.1 (289/286) 12 (PU) 7.834 (0.231) 2.10 3.75 29.50 (0.87) 143.3 (290) 3 (DB) 7.901 (0.233) 1.10 3.81 30.18 (0.89) 142.8 / 141.1 (289/286) 11 (PU) 7.223 (0.213) 3.90 4.34 31.20 (0.92) 135 (275) 14 (PU) 9.529 (0.281) 1.23 3.29 31.20 (0.92) 143.3 (290) 13 (PU) 9.19 (0.271) 2.10 3.61 33.23 (0.98) 143.3 (290) 7 (DB) 10.377 (0.306) 1.40 3.36 34.93 (1.03) 142.8 / 141.1 (289/286) 2 (DB) 11.089 (0.237) 1.10 3.18 35.27 (1.04) 142.8 / 141.1 (289/286) 15 (PU) 9.563 (0.282) 3.90 4.04 38.66 (1.14) 135 (275) 16 (PU) 13.056 (0.385) 2.10 3.08 40.35 (1.19) 143.3 (290) Kami (DB) 9.834 (0.29) 2.90 4.19 41.37 (1.22) Do not measure Control Number 2 (DB) 10.173 (0.30) 1.86 4.10 4.1.71 (1.23) 137.8 / 135 (280/275)

The present invention can be characterized quantitatively by using a coefficient obtained by multiplying the poison ratio at 10% longitudinal elongation by the basis weight of the nonwoven. The coefficient can be expressed as g / m ² (osy) · PR, where “PR” is the poison beam. Whether the nonwoven web of the present invention is a high density discontinuous bonded fabric or a patterned non-bonded fabric, the coefficient will appear below 40.69 g / m ² (1.20 osy) .PR.

While one preferred embodiment of the present invention has been described using specific terms, apparatus, and methods, this technique is for illustrative purposes only. The language used is a language to describe rather than a language of limitation. It should be understood that modifications and variations are possible by those skilled in the art without departing from the spirit and scope of the invention as set forth in the claims below. In addition, it should be understood that the facets of the various embodiments may be interchanged both in whole or in part.

Claims (28)

The basis weight is less than 13.56 g / m ² (0.40 osy), there is a pattern of bonding areas on its surface, and by multiplying the basis weight of the nonwoven web by the poison ratio of the nonwoven web at 10% longitudinal elongation An ultralight nonwoven of dimensional stability characterized by comprising a nonwoven web of fibers or filaments, characterized by a coefficient being calculated and having a dimensional stability of 40.69 g / m ² (1.20 osy) · PR or less. The nonwoven fabric of Claim 1 in which the said pattern of joining area | region is continuous shape. The nonwoven fabric of claim 1, wherein the basis weight of the nonwoven web is less than about 10.17 g / m ² (about 0.30 osy). The nonwoven fabric of claim 1, wherein the basis weight of the nonwoven web is less than about 6.78 g / m ² (about 0.20 osy). The nonwoven fabric of claim 1, wherein the joining region makes up about 50% of the total area of the surface. The nonwoven fabric of claim 1, wherein the bonding area comprises about 40% or less of the total area of the surface. The nonwoven fabric of claim 1, wherein the bonding area comprises about 30% of the total area of the surface. The nonwoven fabric of claim 1, wherein the bonding area comprises about 15% of the total area of the surface. The nonwoven fabric of claim 1, wherein said pattern of joining regions consists of a plurality of discrete point joints. 10. The nonwoven fabric of claim 9, wherein the bond region produces a web having a point bond density of at least about 62 pin bond points / cm ² (about 400 pin bond points / inch ² ). The nonwoven fabric of claim 1, wherein the nonwoven web comprises meltblown filaments. The nonwoven fabric of claim 1, wherein the nonwoven web comprises spunbond fibers. The nonwoven fabric of claim 1, wherein the nonwoven web comprises multicomponent filaments. The nonwoven fabric of claim 1, wherein the nonwoven web comprises thermoplastic fibers. The nonwoven fabric of claim 1, wherein the nonwoven web comprises polypropylene fibers. A personal hygiene product comprising the nonwoven fabric of claim 1 as a facing. 17. The personal care product of claim 16 wherein the nonwoven web comprises spunbond polyolefin fibers. The personal hygiene product of claim 16 which is an adult incontinence product. The personal hygiene product of claim 16 which is a women's health product. The personal care product of claim 16 which is a diaper. The basis weight is less than 13.56 g / m ² (0.40 osy), there is a pattern of continuous bonding areas on its surface, and is calculated by multiplying the base weight of the nonwoven web by the poison ratio of the nonwoven web at 10% longitudinal elongation. Ultralight nonwoven with dimensional stability, characterized in that it comprises a nonwoven web of fibers or filaments, characterized by a modulus and having a dimensional stability of 40.69 g / m ² (1.20 osy) · PR or less. The basis weight is less than 13.56 g / m ² (0.40 osy) and there is a pattern of discontinuous bonding areas on its surface, which is calculated by multiplying the base weight of the nonwoven web by the poison ratio of the nonwoven web at 10% longitudinal elongation. Ultralight nonwoven with dimensional stability, characterized in that it comprises a nonwoven web of fibers or filaments, characterized by a modulus and having a dimensional stability of 40.69 g / m ² (1.20 osy) · PR or less. Providing a nonwoven web having a fiber structure of unbonded individual fibers or filaments having a basis weight of less than 13.56 g / m ² (0.40 osy), On the surface of the nonwoven web, it is characterized by a coefficient calculated by multiplying the poison weight of the nonwoven web at a 10% longitudinal elongation by the basis weight of the nonwoven web and the coefficient being less than 40.69 g / m ² (1.20 osy) PR. A method of making a light weight nonwoven fabric, the method comprising generating a pattern of bonded areas that results in dimensional stability. 24. The method of claim 23, wherein the pattern of bond regions created on the surface of the nonwoven web is continuous. The method of claim 23, wherein the pattern of bond regions created on the surface of the nonwoven web is discontinuous. The method of claim 25, wherein the pattern of bond regions created on the surface of the nonwoven web results in a web having a bond density of at least about 62 pin bond points / cm ² (about 400 pin bond points / inch ² ). . 24. The method of claim 23, wherein a roll with a plurality of depressions is used to create the pattern of bond areas on the surface of the nonwoven web. 24. The method of claim 23, wherein a roll with a plurality of protrusions is used to create the pattern of bond areas on the surface of the nonwoven web.