RU2279267C2 - Suction material having excellent suction and capillary suction properties - Google Patents

Abstract

FIELD: medicine, in particular, suction systems for manufacturing personal hygiene articles.

SUBSTANCE: suction system has suction material located within extendable layer. Second outer layer may be located at side opposite extendable layer. At least one of outer layers should be moisture-permeable. Said layers may be joined with one another through patterned connection. Suction system may be manufactured from one layer or plurality of layers and may be made as, for example, laminated materials formed by pulling to form necking, laminated materials formed by pulling to form necking, laminated materials formed by pulling, and laminated materials formed by pulling with zero extension. Additional layer may be provided within structure, said layer being adapted for enabling capillary suction. Said suction system is suitable for employment in personal hygiene articles such as napkins, sportive trunks, clothing for individuals suffering incontinence, women's personal hygiene articles.

EFFECT: improved suction and distribution capacity of suction article wherein sufficient effectiveness of supersucking layer in capillary suction is kept.

21 cl, 2 ex

Description

State of the art

The present invention relates to restraint materials primarily intended for use in personal care products, such as diapers, training pants, swimwear, absorbent men's underwear, products for adults with incontinence, and personal care products for women. This material can also be used in other products, such as, for example, bandages and dressings, bibs, and in products intended for veterinary medicine.

Products intended for personal hygiene usually contain some absorbent material designed to absorb body fluids. This absorbent material, or absorbent interior, is usually made of several layers or materials and may in various proportions contain natural fibers, synthetic fibers and ground superabsorbent material. When a liquid, such as urine, enters a personal hygiene item such as a diaper, it passes through the uppermost layers, usually the layer facing the body, and a distribution layer designed to temporarily hold the liquid. After passing through these upper layers, urine enters the absorbent interior of the product. Absorbent interior constantly holds liquid. In the case of an absorbent interior containing ground superabsorbent material, the amount of absorbed liquid is determined by the ultimate absorption capacity of the ground superabsorbent material.

The absorbency of superabsorbent materials may be limited due to physical limitations inherent in the system. If the super absorbent material is located in a confined space and cannot swell when in contact with a liquid, the amount of absorbed liquid will be limited. If the super absorbent material swells and cannot expand freely, then the pores between the particles of the super absorbent material will shrink and contract in size. Ultimate reduction in pore size leads to a phenomenon known as “gel blocking,” in which further fluid intake ceases due to the expansion of the super absorbent material in the fluid intake region, and capillary absorption of the fluid in the super absorbent material layer is stopped. This can happen even when other parts of the absorbent core are not wetted with liquid, and it is obvious that in this case the super absorbent material is used uneconomically and inefficiently. On the other hand, if the superabsorbent material is allowed to swell without restriction, then the pore size will become too large for capillary absorption of the liquid to a certain height, and this will ultimately block the flow of liquid. Therefore, it is desirable to provide the superabsorbent material with the ability to swell in a controlled manner and to a controlled degree, so that pore integrity is maintained and capillary absorption continues and contact is maintained between any materials capable of capillary absorption and the superabsorbent material, and also between the particles of the superabsorbent material.

Thus, an absorbent core system is needed that will have good absorbency and dispersibility, and which will also retain sufficient capillary absorbency of the super absorbent layer, so that the absorbent core is used to a greater extent. In such a system, pore integrity and a suitable pore size distribution should be maintained to a large extent, so that the liquid can continue to be absorbed despite the wetting of the outer portions of the absorbent core.

Summary of invention

To overcome the above difficulties and tasks of the prior art, a new absorbent interior system for personal care products has been developed, in which a layer containing superabsorbent material is located between two layers. The first layer is a stretchable outer layer, and the second layer is on the side opposite to the first layer. At least one of the layers is moisture permeable. Layers can be connected to each other by means of communication in the form of a pattern. Both outer layers can be stretchable and / or elastic and, depending on the material used for the layer (s), the direction of stretching can be controlled.

A separate layer capable of capillary absorption may also be contained.

Definitions

"Disposable" refers to the fact that after a single use should be discarded, and not subjected to washing and reuse.

“Liquid transfer” means that the liquid can transfer from one layer to another layer or from one section to another section within the layer.

“Hydrophilic” refers to fibers or surfaces of fibers that are wetted by aqueous liquids in contact with the fibers. In turn, the degree of wetting of the materials can be characterized using the contact angles and surface tension of the contacting liquids and materials. The Cahn SFA-222 Surface Force Analyzer System or basically equivalent systems can be used to measure the wettability of specific fibrous materials and mixtures of fibrous materials. When measured using this system, fibers characterized by contact angles less than 90 ° are considered to be “wettable” or hydrophilic, and fibers characterized by contact angles greater than 90 ° are considered to be “non-wettable” or hydrophobic.

As used in the present invention, the term "nonwoven fabric or fabric" means a material whose structure is formed by individual fibers or strands that are intertwined, but not in the same way as a knitted fabric. Non-woven materials or webs are formed using various methods, such as, for example, aerodynamic methods for producing from a melt, spunbond production methods, and methods for manufacturing a non-woven material from a carded web. The mass of a unit area of nonwoven materials is usually expressed in ounces of material per square yard (osy) or in grams per square meter (g / m ² ), and fiber diameters are usually expressed in micrometers (Note that to convert osy to g / m ² osy at 33.91).

The term “spunbond fibers” means fibers of small diameter that are formed by extruding molten thermoplastic material in the form of filaments through a plurality of thin capillary channels of a spinneret. Such a method is disclosed, for example, in US Pat. No. 4,340,563 to Appel et al. And US Pat. No. 3,802,817 to Matsuki et al. The fibers may also have a shape, such as described, for example, in US Pat. No. 5,277,976 to Hogle et al., Which describes non-standard shaped fibers.

"Carded nonwoven web" means a web made of staple fibers that are passed through a combing or carding device in which the staple fibers are detached or torn off and aligned in the longitudinal direction to form a fibrous nonwoven fabric oriented substantially in the longitudinal direction. This material can be bonded by methods that include point bonding, bonding by air purging, ultrasonic bonding, adhesive bonding, and the like.

“Aerodynamic molding” is a known method by which a fibrous nonwoven layer can be formed. In the method of aerodynamic molding, bundles of small fibers, the typical length of which varies from about 3 to about 52 millimeters (mm), are separated and captured by the flow of air, and then deposited on the forming grid, usually using a vacuum feed. Then randomly deposited fibers are bonded to each other using, for example, hot air or spraying glue. Aerodynamic molding is described, for example, in US Pat. No. 4,640,810 to Laursen et al.

Various methods are known for binding nonwoven webs. These include bonding by air purging, stitch bonding, ultrasonic bonding, point bonding and patterned (or point) loosening. Examples of such binding methods are given in US patents US 4891957 issued by Strack et al., US 4374888 issued by Bornslaeger, US 3855046 issued by Hansen and Pennings, and US 5858515 issued by Stokes et al.

As used in the present invention, the term “elastic composite material” means an elastic material, which may be a multicomponent material or a multilayer material in which at least one layer is elastic. Such materials may be, for example, laminated materials, “molded with a hood”, laminated materials “molded with a hood”, laminated materials, “molded with a hood and hood”, and laminated materials, “molded with a hood” zero stretch. "

“Neck-assisted molding” means a method in which an elastic element is bonded to an inelastic element such that only the inelastic element is stretched or extended into the neck so that its size decreases in a direction perpendicular to the stretching. “Neck-molded laminate” means a composite elastic material manufactured by a neck-extrusion molding process, i.e. in which the layers are bonded to each other when only the inelastic material is in a stretched state. Such laminated materials usually have the ability to stretch in the transverse direction. Examples of laminated neck-molded materials are those described in US patents US 5226992, 4981747, 4965122 and 5336545 issued by Morman et al., And US patent 5514470 issued by Haffner et al.

Generally, “stretch molding” means a method in which an elastic element is bonded to another element, such that only the elastic element stretches at least about 25% of its length in a shortened state. “Laminate material formed with a hood” means a composite elastic material made by a method of molding with a hood, i.e. in which the layers are connected to each other when only the elastic material is in a stretched state, so that after the reduction of the layers, the inelastic layer is assembled. Such laminates generally have the ability to stretch in the longitudinal direction and can be stretched to the extent that the inelastic material assembled between the bonding positions allows the elastic material to elongate. One type of extrusion molded laminate is disclosed, for example, in US Pat. No. 4,720,415 to Vander Wielen et al., Which uses multiple layers of the same polymer, obtained using multiple extruder groups. Other composite elastic materials are disclosed in US Pat. No. 4,789,699 to Kieffer et al., US Pat. No. 4,781,966 to Taylor, and US Pat. Nos. 4,657,802 and 4,652,487 to Morman and 4,652,487 to Morman et al.

In particular, US Pat. No. 4,657,802 discloses a method for manufacturing a composite nonwoven elastic fabric comprising a nonwoven elastic fabric bonded to a fibrous nonwoven assembled fabric. The method includes the steps of manufacturing a nonwoven elastic web having a shortened length, i.e. unchanged length, and length in the extended state, i.e. altered length, stretching the non-woven elastic fabric to its length in an extended state, i.e. altered length, forming a fibrous non-woven sorbable fabric directly on the surface of the non-woven elastic fabric in its elongated state, i.e. with a modified length, molding the composite non-woven elastic fabric by binding the fibrous non-woven fabric to be woven with the non-woven elastic fabric while maintaining the non-woven elastic fabric in its elongated state, and reducing the non-woven elastic fabric to its length in a reduced state to assemble the fibrous non-woven fabric to be woven. The bonding of the fibrous non-woven sorbable fabric to the non-woven elastic fabric occurs simultaneously with the formation of the sorbable fabric on the surface of the elastic fabric.

Generally, “neck-and-hood molding” means a method in which an elastic element is bonded to another element, such that the elastic element stretches at least about 25% of its length in a shortened state, and the second layer is elongated in neck inelastic layer. "Layered material molded with a hood and a hood" means a composite elastic material made by molding with a hood and a hood, i.e. in which the layers are connected to each other when both layers are in an extended state, and then they are given the opportunity to contract. Such laminates usually have the ability to stretch in all directions.

Typically, “zero stretch” stretch molding means a process in which at least two layers are bonded to each other while being in an unstretched (hence zero stretching) state, wherein one of the layers is stretchable and elastomeric, and the other stretchable, but not necessarily elastomeric. Such a layered material is subjected to extraction locally by using one or more pairs of engaging corrugated rolls that reduce the degree of deformation of the web. “Zero stretch hood molded material” means a composite elastic material manufactured by a zero stretch hood molding method, i.e. in which the elastic and inelastic layers are connected to each other when both layers are in an unstretched state, and are subjected to drawing using catching grooved rolls. After drawing the laminate, the second layer at least to some extent remains in a constantly elongated state, so that after the cessation of the pulling force, the laminate does not return to its original, undeformed state. This leads to the fact that the layered material becomes bulky in the z-direction and for this reason acquires elastic extensibility in the direction of the original drawing, at least to the extent to which it was subjected to drawing initially. Examples of such laminates and methods for their manufacture are given in US patents US 5143679, issued by Weber et al., US 5151092, issued by Buell et al., US 5167897, issued by Weber et al., And US 5196000, issued by Clear et al.

“Personal hygiene products” means articles designed to absorb body exudates, such as diapers, training pants, swimwear, absorbent men’s underwear, incontinence products for adults, dressings, veterinary and funeral products, and women’s personal hygiene products .

“Target site” means a site or position on a personal hygiene item that is normally exposed to a user's discharge.

Research Methods and Materials

Unit Area Weight: The unit area weight can be determined by cutting out a circular sample with a diameter of 7.6 cm (3 inches) and weighing it on a balance. The mass is recorded in grams. The mass is divided by the area of the sample.

Caliber material (thickness) gauge material is a measure of thickness and is measured in millimeters at a pressure of 0.05 pounds / ⁱⁿ² (3.5 g / cm ²⁾ with a tester for bulk materials STARRET® type.

Density: The density of materials is calculated by dividing the mass per unit area of the sample, expressed in grams per square meter (g / m ² ), by the caliber of the material, expressed in millimeters (mm). Caliber should be measured at 0.05 pounds / ⁱⁿ² (3.5 g / cm ²⁾ as mentioned above. The result is multiplied by 0.001 and the resulting value is converted into grams per cubic centimeter (g / cm ³ ).

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an absorbent system used in personal care products to provide good capillary absorption and absorbency.

In one embodiment, the present invention includes an absorbent material surrounded by an elastic web. The absorbent material may include superabsorbent material in various forms: in the form of particles, fibers, foams, and the like, and it may include natural fibers, binders, and synthetic fibers. In this embodiment of the present invention, the elastic material should be a moisture permeable layer. Moisture-permeable materials include perforated, containing filler and fibrillated films, woven and non-woven fabrics, open-cell foams, mesh materials and any other layer that allows the passage of liquid water. The elastic material may also be any suitable moisture permeable elastic material bonded to the fabric using elastic latex. This absorbent system can be made by placing the absorbent material on the elastic material and wrapping the elastic material to include the absorbent material into it to form the finished absorbent system.

In yet another embodiment of the present invention, the absorbent system can be made of two elastic layers between which absorbent material is placed. In this embodiment, the layers are also preferably bonded to each other in some way to hold the absorbent material, and only one layer should be moisture permeable. If both layers are elastic, they can be elastic in the same direction, in different directions or in all directions. If they are both elastic in the same direction, then the laminate will be elastic in this direction in a wet or dry state. Suitable elastic materials that are elastic in one direction include stretch-molded laminate materials and neck-molded laminate materials discussed above. Materials that are flexible in all directions include laminates formed with a hood in the neck and with the hood, also discussed above. The elastic material may be any suitable material, such as an elastic perforated film, a woven or non-woven fabric, or mesh material. The elastic material may also be any suitable moisture permeable material bonded to other materials using elastic latex. The elastic layer may also be moisture permeable.

In another embodiment of the present invention, the absorbent system may be made of two stretch layers between which absorbent material is placed. It is preferable to connect the layers to each other by means of a patterned connection such that the absorbent material is held in approximately the same place when the absorbent system is moved. In this embodiment of the present invention, only one of the outer layers should be moisture permeable.

In another embodiment of the present invention, the absorbent system may be made of an elastic layer and an extensible layer between which absorbent material is placed. The layers are preferably bonded to each other using a pattern such that the absorbent material is held in approximately the same place when the absorbent system is moved. In this embodiment of the present invention, only one of the outer layers should be moisture permeable.

In another embodiment of the present invention, the absorbent system may be made of an inextensible layer and an extensible layer between which the absorbent material is placed. The layers are preferably bonded to each other using a pattern such that the absorbent material is held in approximately the same place when the absorbent system is moved. In this embodiment of the present invention, only one of the outer layers should be moisture permeable.

The stretchable layer in these embodiments of the present invention may be, for example, a spunbond production material that is reversibly elongated in the neck, as described in US Pat. , this material is capable of stretching at least about 75%, and reducing at least about 50 percent. This material is made by applying a tensile force to at least one material to stretch this material into the neck, heat the material stretched into the neck and cool the material stretched into the neck, so that the material reversibly drawn into the neck has a higher heat of fusion and / or lower temperature the beginning of melting than the materials elongated in the neck before heating.

In another embodiment of the present invention, the absorbent system may be made of a flat non-elastic layer and an elastic layer with absorbent materials placed between the two layers. It is preferable to connect the layers to each other by means of a bond in the form of a pattern such that, when the absorbent system is moved, the absorbent material is held in approximately the same place. In this embodiment of the present invention, only one of the outer layers should be moisture permeable.

Due to the vast array of composite elastic materials, many other embodiments of the present invention are possible. The outer layers of the absorbent system can contain many layers and they can be, for example, laminated materials molded with a hood into a neck, laminated materials molded with a hood, laminated materials molded with a hood and hood, and laminated materials molded with a hood with zero stretch.

In any of the embodiments of the present invention, additional layers may be placed in the structure. In particular, in order to make capillary absorption better than that of the outer layers or absorbent material, a layer of non-woven carded material, an aerofoil-formed material, or a spunbond material can be placed inside the system. A cross section of such a structure may include a capillary absorbent layer in the middle, with absorbent material on one or both sides, and subsequent outer layers.

It should be noted that if a layered material that is elastic or extensible in one or more directions is needed, then inelastic materials should not be used in such a way that they limit stretching. Therefore, superabsorbent materials or other materials contained in the inner layer must be in powdered form or in the form of short fibers, i.e. in discrete form to allow movement, or if they are not in discrete form, such as long fibers, foam, film or non-woven material, they must be flexible.

Materials suitable for the manufacture of the outer layers of the system can be non-woven fabrics made from elastomeric and non-elastomeric polymers in accordance with various methods known to specialists in this field of technology, including the production of aerodynamic methods from the melt, spunbond production method, obtaining from carding and aerodynamic molding. The canvases can also be knitted by known methods, including bonding by blowing air, bonding with stitches, ultrasonic bonding, dot bonding and patterned (or dot) loosening. In the embodiment of the present invention can also be used moisture-permeable elastomeric and non-elastomeric films, which include perforated, fibrillated and containing filler films.

The extensible layer allows the superabsorbent material to swell after wetting to a controlled degree, so that pore integrity and suitable pore size and distribution are maintained, and capillary absorption of the liquid through the superabsorbent material is continued sufficiently. The regulation of pore size and their distribution can be carried out by appropriate tension of the material of the stretchable layer in accordance with the curvature of the body underneath, and thus regulate the pressure on the layer containing super absorbent material. By appropriately distributing the stress in the tensile material, it is possible to make the pressure change in accordance with the height. In addition to the usual known superabsorbent materials, any swellable materials in a liquid should act similarly.

The elastomeric polymers used in the embodiment of the present invention may be polymers made from block copolymers such as polyurethanes, copolymers of ethers and amides, block copolymers of ethers and amides, copolymers of ethylene with vinyl acetate (EVA), block copolymers having the general formula of type ABA or AB, such as copolymer (styrene / ethylene-butylene), styrene-poly (ethylene-propylene) -styrene, styrene-poly (ethylene-butylene) -styrene, (polystyrene / poly (ethylene-butylene) / polystyrene), poly- (styrene / ethylene-butylene / styrene), and the like. Elastomeric copolymers and the formation of elastomeric non-woven webs from these elastomeric copolymers are disclosed, for example, in US Pat. Examples of such commercial elastomeric copolymers are, for example, materials known as KRATON®, manufactured by Shell Chemical Company of Houston, Texas. KRATON® block copolymers are available in several different compositions, some of which are described in US Pat. Nos. 4,663,220, 4,323,534, 4,834,738, 5,093,422 and 5,305,599.

In the embodiment of the present invention, polymers consisting of elastomeric tetrablock copolymers A-B-A-B can also be used. Such polymers are disclosed in US Pat. No. 5,332,613 to Taylor et al. In such polymers, A is a block of a thermoplastic polymer, and B is a monomeric isoprene unit, mainly hydrogenated to a monomer unit of a propylene-ethylene copolymer. An example of such a tetrablock copolymer is the styrene-poly (ethylene-propylene) -styrene-poly (ethylene-propylene) elastomeric block copolymer, or SEPSEP, sold by Shell Chemical Company of Houston, Texas under the trade name KRATON®.

Other typical elastomeric materials that may be used include polyurethane elastomeric materials, such as, for example, sold under the trade name ESTANE® by B.F. Goodrich & Co. and MORTHANE® manufactured by Morion Thiokol Corp., elastomeric materials made from polyesters, such as, for example, sold under the trade name HYTREL® by E.I. DuPont de Nemours & Company, both sold under the trade name ARNITEL®, formerly manufactured by Akzo Plastics of Arnhem, Holland, and now manufactured by DSM ofSittard, Holland.

Another suitable material is an ester-amide block copolymer having the formula:

Such materials of various grades under the trade name REVAX® are manufactured by ELF Atochem Inc. of Glen Rock, New Jersey. Examples of the use of such polymers are given in US patents 4,724,184, 4,820,572 and 4,923,742 to Killian et al.

Thermoplastic elastomers from ester copolymers include copolymers of ethers and esters of the general formula:

where G is selected from the group consisting of poly (oxyethylene) alpha, mega-diol, poly (hydroxypropylene) alpha, mega-diol, poly (oxytetramethylene) alpha, mega-diol, and a and b are positive integers, including values 2, 4 and 6, m and n are positive integers, including values 1-20. Such materials typically have an elongation at break of about 600 to about 750%, as measured in accordance with ASTM D-638, and a melting point of about 350 to about 400 ° F (176 to 205 ° C) when measured in accordance with ASTM D-2117. Examples of commercially available such ester copolymer materials include, for example, materials known as ARNITEL®, formerly manufactured by Akzo Plastics of Arnhem, Holland, and now available by DSM ofSittard, Holland, and also known as HYTREL®, available by E.I. duPont de Nemours of Wilmington, Delaware. The formation of an elastomeric nonwoven fabric from elastomeric materials made from polyesters is disclosed, for example, in US Pat. No. 4,741,949 to Morman et al. And US Pat. No. 4,707,398 to Boggs.

Elastic polyolefins are also used in the practice of the present invention. Such polymers are called "metallocene" polymers and are marketed by Exxon Chemical Company of Baytown, Texas under the trade names ACHIEVE® for propylene polymers and EXACT® and EXCEED® for ethylene polymers. Dow Chemical Company of Midland, Michigan produces polymers sold under the name ENGAGE®. These materials are believed to be made using non-stereoselective metallocene catalysts. Exxon generally refers to the metallocene catalysts used in its technology as “one-center catalysts,” while Dow refers to its catalysts with “geometry constraints” to distinguish them from conventional Ziegler-Natta catalysts with many reaction centers, and releases them under the name INSIGHT®. In the practice of the present invention, elastic polyolefins such as polypropylene and polyethylene are preferred, and elastic polypropylene is most preferred.

Natural fibers include wool, cotton, flax, hemp and wood pulp. Wood pulp includes standard soft fuzzy grade wood such as CR-1654 (US Alliance Pulp Mills, Coosa, Alabama). Cellulose can be modified to enhance the valuable characteristics of the fibers and their processability. Curl can be imparted to the fibers by methods involving chemical treatment or mechanical torsion. Curl is usually attached before stitching or stiffening. Cellulose can be stiffened with crosslinking agents such as formaldehyde or its derivatives, glutaraldehyde, epichlorohydrin, methylated compounds such as urea or urea derivatives, dialdehydes such as maleic anhydride, unmethylated urea derivatives, citric acid or other polybasic carboxylic acids . Some of these reagents are less preferred than others due to their harmful effects on the environment and human health. Cellulose can also be made tougher by heating or alkali treatment, such as mercerization. Examples of these types of fibers include NHB416, a chemically cross-linked cellulosic softwood fiber from southern trees that have an increased wet modulus from Weyerhaeuser Corporation of Tacoma, WA. Other pulp grades used are loose pulp (NF405) and loose pulp (NB416), also available from Weyerhaeuser. HPZ3 manufactured by Buckeye Technologies, Inc. of Memphis, TN, has undergone a chemical treatment which, along with providing additional rigidity in the dry and wet state and elasticity, gives the fiber a crimp and curl. Another suitable pulp is Buckeye HPF2, and IP IP SUPERSOFT® from International Paper Corporation is another. Suitable artificial silk fibers are 1.5 denier fibers of Merge 18453 manufactured by Tencel Incorporated of Axis, Alabama.

Super absorbent materials that are suitable for use in the present invention can be selected from classes based on chemical structure as well as physical condition. These include superabsorbent materials with low gel strength, high gel strength, surface crosslinked superabsorbent materials, uniformly crosslinked superabsorbent materials, and superabsorbent materials with a variable crosslink density in the structure. Super absorbent materials can be based on chemical structures that include polyacrylic acid, a copolymer of isobutylene with maleic anhydride, polyethylene oxide, carboxyl methyl cellulose, polyvinyl pyrrolidone and polyvinyl alcohol. Super absorbent materials can have different swelling rates - from low to high. Super absorbent materials may be in the form of foams, macroporous or microporous particles or fibers, particles or fibers with fibrous or finely dispersed coatings, or materials having fibrous or finely divided morphology. Super absorbent materials may be in the form of tapes, particles, fibers, sheets or films. Super absorbent materials can have different lengths and diameters and different distributions of these values. Super absorbent materials can be in varying degrees of neutralization. Counterions are usually Li, Na, K, Ca.

The materials of the present invention may include superabsorbent materials of the above types. Typical superabsorbent materials are manufactured by The Dow Chemical Company. An example of these types of superabsorbent materials is stockhausen, Inc. under the name FAVOR® SXM 880. An example of fibrous superabsorbent materials may be a material manufactured by Camelot Technologies, Ltd., of High River, Alberta, Canada, under the name FIBERDRI® 1241. Another example of these types of superabsorbent materials may be a material manufactured by Chemtall Inc. of Riceboro, GA, under the name FLOSORB 60 LADY®, also known as LADYSORB 60®. Examples of superabsorbent materials coated with fibers or fine particles are microcrystalline cellulose coated on FAVOR® 880 and FAVOR® 880 coated on cellulose fibers. They are described in provisional patent application US 60/129774. Other types of superabsorbent materials not listed in the present invention that are publicly available and known to those skilled in the art can also be used in the present invention.

The binders commonly used in these structures help to impart mechanical integrity and stabilization. Binders include fibers, liquids, or other binders that can be thermally activated. Preferred for inclusion are fibers having a melting point close to the melting point of polyolefin fibers. Low melting polymers give the material the ability to bind at the points of contact of the fibers when heated. In addition, fibers made from low melting polymers such as bicomponent and bicomponent fibers are suitable for practicing the present invention. Fibers made from low melting polymers are commonly referred to as "low melting fibers". "Low melting polymers" means polymers whose glass transition temperature is below about 175 ° C. It should be noted that the texture of the absorbent fabric can be modified from soft to hard by selecting the glass transition temperature of the polymer. Typical binder fibers include bicomponent fibers of polyolefins, polyamides and polyesters. Three suitable binder fibers are bicomponent core fibers manufactured by KoSa Inc. (Charlotte, North Carolina) called T-255, polyethylene / polyethylene terephthalate fibers and T-256, or Copolyester, although many suitable binder fibers are known to those skilled in the art and are available from many manufacturers such as Chisso and Fibervisions LLC of Wilmington DE. KoSa has developed suitable binder fibers with a core fiber structure from the ester copolymer known as T-254 (low melting polyethylene terephthalate copolymer). A suitable liquid binder is KYMENE® 557LX, available from Hercules Inc. of Wilmington, DE. Other suitable liquid binders include emulsion ethylene vinyl acetate copolymers sold by National Starch and Chemical Company (Bridgewater, New Jersey) under the trade name DUR-O-SET® ELITE® series (including ELITE® 33 and ELITE® 22). Air Products Polymer and Chemicals sells other suitable binder fibers called AIRFLEX®.

The fibers used to produce materials suitable for use in the present invention can be single-component, conjugate (two-component), multi-component or two-element fibers. If they are conjugated, they may have a parallel configuration, a fiber configuration with a core, or an island configuration. The fibers may be crimped or crimped in accordance with, for example, US Pat. No. 5,382,400 to Pike.

The following are examples of suitable absorbent systems of the present invention:

Example 1

Layered material is obtained using outer layers of laminated material formed with a hood (CER), both layers being pulled in the same direction in accordance with US patent US 4657802, issued by Morman. CCBs are made by stretching the elastic layer obtained by the aerodynamic method from the melt and bonding it to the inelastic layer on both sides. An elastic layer is a melt-blown layer having a unit mass of 71 g / m ² (2.1 osy) made of KRATON® G-2740 polymer. Inelastic layers are those of a spunbond production method having an area weight of 30.9 g / m ² (0.91 osy) made of polypropylene, ESCORENE® polymer manufactured by Exxon Chemical Corp. The mass of the CCB area unit is 132.6 g / m ² (3.9 osy).

One surface layer is removed from the CER material, and this first CER layer is placed on a flat surface with the upstream side melt-blown. Particles of super absorbent material, in this case FAVOR® 880 super absorbent material, are distributed over the CER layer in the amount of 88.8 g / m ² (2.62 osy). The second layer of the same CER with the downward side obtained by the melt aerodynamically from the melt is placed on a super absorbent material and the layers are laminated in a press to form a square net binding pattern with a square side of about 12 mm (half inch) at a piston pressure of 421, 9 kg / cm ² (6000 lb / in ² ). Use a press manufactured by PHI in the City of Industry, California, Model No. 0230 C-X1-4B-7, serial No. 92-10-012. The mass per unit area of the layered material is 293 g / m ² (8.64 osy).

The dry laminate is very thin, stretchable and takes the form of a body. Samples of the following sizes were cut: 6 cm (2.375 inches) in the drawing direction and 8.26 cm (3.25 inches) in the direction in which the drawing was not carried out, 2.5 mm (0.099 inches) thick. This sample has a mass of 1.46 g and is pulled to a length of about 11.4 cm (4.5 inches) using normal hand tension.

The sample is placed in water for about half an hour, into which a small amount of surfactant has been added. After that, the sample has a length of 5.7 cm (2.25 inches), a width of 7.6 cm (3 inches), and its thickness varies from 8.1 to 13.3 mm (from 0.319 to 0.525 inches) . The sample has a mass of 26.9 g and is pulled to a length of 10.2 cm (4.25 inches), with approximately the same tension being created by the hand of the same person as above.

As can be seen from these data, the thickness of the sample in the wet state is more than about 3 times greater than its thickness in the dry state, however, the extensibility in the wet and dry state is approximately the same. Mass and thickness change due to water absorption, but other characteristics remain unchanged.

Example 2

The two aerodynamically prepared layers are used to make a capillary absorbent laminate sample and a control sample, each of which is 5.1 cm by 15.24 cm (2 inches by 6 inches) in size. The capillary absorbent aerodynamically prepared layer was made using 90 wt.% Weyerhaueser NB416 cellulose and 10 wt.% T-255 Merge 34821 A binder fibers, 6 mm, 2.8 denier. The aerodynamically obtained layer capable of capillary absorption has an area mass of 150 g / m ² , a density of 0.15 g / cm ³ and a thickness of 1 mm. The layers obtained by the aerodynamic method have a mass equal to 1.05 and 1.08 g.

Control sample

A sample weighing 1.08 g of the aerodynamic fabric is vertically placed so that approximately 2.54 cm (1 inch) of the aerodynamically produced layer is immersed in water. After 1.5 hours, the sample was removed from the water, allowed to drain for 10 s and weighed. The sample obtained by the aerodynamic method, has a mass equal to 12.45 g, which meant that he absorbed 11.37 g of water or 10.5 g of water per 1 g of tissue obtained by the aerodynamic method.

Capillary Absorbent Sample

Glue is sprayed onto another aerodynamic fabric sample, in this case lighter, and sprinkled with particles of FAVOR® 880 super absorbent material. 0.67 g is applied to this sample. This procedure is carried out on the other side of the same aerodynamic sample . On the second side, 1.57 g are applied.

The material of the structure (fabric obtained by the aerodynamic method) / (super absorbent material) is placed on a sample of one-sided CERs (the same as in Example 1). The size of the CERs is 15.24 cm (6 inches) in the direction in which the hood is not drawn, and 10.12 cm (4 inches) in the direction of the hood where the direction in which the hood is not drawn is the longitudinal direction of the aerodynamic layer way. The CERs are folded over the end of the aerodynamically formed layer, and the three edges are welded together, leaving an excess of material obtained by the aerodynamic method projecting approximately 5.1 cm (2 inches) from the CERs. The width of the adhesive layer is approximately 2.5 cm (1 inch). Then the sample is capable of wicking, welded using Carver press at a pressure of 1000 lbs / in ² for 5 seconds and slightly trimmed to dimensions of about 7.6 cm by 6.3 cm (3 inches by 2.5 inches) . A capillary absorbent sample has a mass of 5.45 g.

A capillary absorbent sample was placed vertically so that approximately 2.54 cm (1 inch) of the aerodynamic material was immersed in water. After 5 minutes, a capillary absorbent sample has a mass of 21.6 g, which means that it has absorbed 16.2 g of water. After 1 min, the sample is placed in its original position and after another 5 min it has a mass of 33.23 g and absorbs 27.8 g of water. After another 1 min, the sample was re-immersed in the same manner for 5 min and it had a mass of 55 g and absorbed 49.6 g of water. The lower welded section of the laminate begins to break, so the test is stopped.

Assuming that a capillary absorbent sample of a layer obtained by an aerodynamic method contains the same amount of water as a control sample, it turns out that a capillary absorbent sample contains 17 g of water per 1 g of super absorbent material. The original CER package has a thickness of about 0.2 cm (0.08 inches), and after the test, it has a thickness of about 2.3 cm (0.92 inches).

With swelling of the super absorbent material, the outer layers of the CER expand, allowing capillary absorption to continue in the aerodynamically obtained layer, since it does not break when the super absorbent material expands.

It is believed that in this embodiment of the present invention, it is important that good contact is maintained between the superabsorbent material and the capillary absorption medium, so that the possibility of transferring liquid to the capillary absorption medium is not lost. Binders or adhesives can be used to attach the super absorbent material to a capillary absorbent medium.

In yet another embodiment of the present invention, the layer of Example 2 obtained by the aerodynamic method, could be assembled prior to lamination in any way, for example, by creping, which allows the layered material to stretch.

As should be clear to specialists in this field of technology, changes and modifications of the present invention are within the competence of specialists in this field of technology. Examples of such changes are contained in the above patents, each of which in its entirety is included in the present invention by reference to the extent consistent with the present invention. Applicants believe that such changes and modifications are included in the scope of the present invention.

Claims (21)

1. A personal care product comprising an absorbent core system, said absorbent core system for maintaining pore integrity and a suitable pore size distribution over a period of time, includes a first elastic outer layer and a second outer layer on the side opposite to said elastic the outer layer, and between these layers is absorbent material, while these layers of the aforementioned system of the absorbent inner part are connected to each other with using patterned communication in order to keep the absorbent material in approximately the same place as the system moves, said absorbent core system being able to expand to allow continuous absorption or capillary absorption of the liquid. 2. The personal care product of claim 1, wherein said absorbent layer includes super absorbent material and cellulose. 3. The personal care product of claim 1, wherein said absorbent layer includes super absorbent material and synthetic fibers. 4. The personal care product of claim 1, wherein said second outer layer is extensible. 5. The personal care product of claim 1, wherein said elastic layer is made of a polymer selected from the group consisting of polyurethanes, block copolymers of esters and amides, polyesters, polyamides, copolymers of ethers and esters and polyolefins. 6. The personal care product of claim 1, wherein said second outer layer is elastic. 7. The personal care product of claim 1, wherein said second outer layer is non-stretch. 8. The personal care product of claim 1, wherein said elastic layer is selected from the group consisting of a perforated film, woven materials, nonwoven materials, and mesh materials. 9. The personal care product of claim 8, further comprising another elastic layer bonded to said first elastic layer using elastic latex glue. 10. The personal care product according to claim 1, wherein said elastic layer is a layered material selected from the group consisting of laminated materials formed with a hood in a neck, laminated materials formed with a hood, and laminated materials with a hood and zero stretch stretch laminated materials. 11. The personal care product according to claim 1, further comprising a capillary absorption layer located between said outer layers. 12. The personal care product of claim 11, wherein said capillary absorption layer is manufactured in accordance with a method selected from the group consisting of a spunbond production method, a method for manufacturing from a carded web, and an aerodynamic method. 13. The personal care product of claim 1, wherein said second outer layer comprises fibers made of a polyolefin. 14. A personal care product comprising an absorbent core system, said absorbent core system for maintaining pore integrity and appropriate pore size distribution over a period of time, includes a capillary absorbent layer comprising a super absorbent material attached to at least at least one side of at least one elastic outer layer and at least one moisture-permeable outer layer, whereby said absorbent inner system able to expand to allow continuous absorption or capillary absorption of the liquid. 15. The personal care product of claim 14, wherein said elastic outer layer is moisture permeable. 16. The personal care product of claim 14, wherein said capillary absorption layer is manufactured in accordance with a method selected from the group consisting of a spunbond production method, a method for manufacturing from a carded web, and an aerodynamic method. 17. The personal care product of claim 14, wherein said elastic layer is a layered material selected from the group consisting of laminated materials formed with a hood in a neck, laminated materials formed with a hood, and laminated materials with a hood and zero stretch stretch laminated materials. 18. A personal care product comprising an absorbent core system, said absorbent core system for maintaining pore integrity and a suitable pore size distribution over a period of time, includes an aerodynamically-formed layer capable of capillary absorption having a unit area mass equal to from 17 to 170 g / m ² (0.5 to 5 osy), said layer capable of wicking, at least on one side comprises a superabsorbent material, and at IU ie, a liquid permeable outer layer of the molded stretch in the neck of the laminate has a mass per unit area of from 17 to 170 g / m ² (0.5 to 5 osy), whereby the said system absorbent core is capable of expanding to provide continuous absorption or capillary absorption of liquid. 19. A personal care product comprising an absorbent core system to maintain pore integrity and a suitable pore size distribution over a period of time, and said absorbent core system includes an absorbent material encapsulated in a moisture-permeable elastic material, wherein the absorbent core system is manufactured by the premises absorbent material onto the elastic material and by wrapping the elastic material to include absorbent material therein, to obtain finished feeding system. 20. A personal care product comprising an absorbent core system to maintain pore integrity and a suitable pore size distribution over a period of time, said absorbent core system comprising a first elastic outer layer and a second outer layer on the side opposite to said elastic the outer layer, and between these layers is absorbent material, while these layers of the aforementioned system of the absorbent inner part are connected to each other by means of a patterned bond in order to keep the absorbent material in approximately the same place as the system moves, and furthermore, said system has a thickness in a dry state, and a thickness in a wet state, and an extensibility in a dry state and wet extensibility, wherein said wet thickness is at least 3 times greater than said dry thickness, and said wet and dry extensibility is about the same, whereby I system absorbent core is capable of expanding to provide prolonged absorption or capillary absorption of fluid. 21. The personal care product of claim 20, wherein said second outer layer is elastic.