PAD FOR BREASTFEEDINGField of the InventionThe present invention generally relates to absorbent pads. More particularly, the present invention relates to improved breastfeeding pads and the methods for making them.
Background of the InventionDuring the final stages of pregnancy and after giving birth it is very common for mothers to produce milk and excess that results in various degrees of runoff. Even though this problem can usually be prolonged throughout the entire period of giving milk to the child, it is often more agod during the initial stages of breastfeeding. The run-off that results from this condition can pass through a brassiere and dampen the mother's clothes. This is highly undesirable and this can contribute to mastitis, to staining clothing stains as well as causing discomfort to the mother when wearing wet clothes. In addition, in many situations, such as in work or in public, umedecimiento of clothing can cause the mother an unwanted tension or grief. Therefore, breastfeeding pads have been developed to improve the comfort and confidence of mothers who are breastfeeding. These pads are intended to absorb retain the runoff of a breastfeeding mother and be placed on the side of the nipple and between the brassiere and the breast. Several breastfeeding pads are commercially available today. Examples of breast pads are described in United States Patent No. 4,047,534 issued to Thomaschefsky et al .; and U.S. Patent No. 3,356.09 issued to Plantinga et al .; in U.S. Patent No. 4,700,699 issued to Tollerud et al., and U.S. Patent No. 5,149,33 to Clarke et al.
Many breastfeeding pads of the prior art suffer from one or more of the disadvantages described below. One of such disadvantages is that the shape of the pad does not easily conform to the shape of the breast. When placed on the brassier during use, the flat disc-shaped pad is forced to conform to the shape of the breast cup and brassiere. However, in doing so, the pad often bulges in one or more places. The bulging of the pad contributes to runoff, can cause discomfort and can also create unnatural or noticeable deformations which appear through the clothing. In addition, flat breast pads may also be prone to move once they are in place, which can result in bulging or an alignment that allows the fluid to make contact with the mother's clothing. In addition, after absorbing the fluid there is a tendency for some of the fluid to migrate to the lower parts of the pad due to gravity. In this aspect, many pads are assembled in such a way that the fluid can escape at the edge of the pad. Still further, the sewing and / or the materials used within the nursing pads are often rough or exhibit poor feel.
Therefore, there is a need for an improved breastfeeding pad with good absorbent properties and which has a pleasant feeling against the skin of the woman. There is also a need for such a pad which is prone to fluid flow through the edge of the pad and which, however, does not have stiff, rough edges which may cause scaling or irritation of the skin. In addition, there is a need for a breastfeeding pad which readily conforms to the shape of the brassiere and breast without bulging. In addition, there is a need for the pad which, once in place, is not prone to move or to dislodge. There is similarly a need for an improved breast pad which is both soft durable while at the same time sufficiently cheap to be disposable.
Synthesis of the InventionThe aforementioned needs are filled and the disadvantages of the prior art are overcome by an absorbent pad of the present invention which comprises a flexible absorbent pad having an inner liquid permeable layer, an absorbent core and an outer liquid impervious layer. The inner layer preferably comprises a non-woven fabric permeable to the liquid of thermoplastic fibers of multiple components. Desirably the liquid permeable layer comprises a nonwoven fabric of bicomponent fibers such as, for example, fibers comprising a polyethylene polymer component and a polypropylene polymer component. One or more components of the multicomponent fibers of the non-woven fabric permeable to the liquid may be hydrophilic. Additionally, the inner layer may be knitted and / or an autogenously bonded fabric. The individual layers of the absorbent pad are joined together and as an example, the layers of the pad can be joined together along the edge and preferably are joined with a continuous join to create a sealed edge. In a further aspect the absorbent pad may comprise a three-dimensionally shaped article having thermoplastic fibers autogenously bonded to both the inner and outer layers.
In still a further aspect of the invention, the absorbent pad may comprise a stabilized matrix of thermoplastic fibers and absorbent material. In one embodiment, the absorbent core may comprise superabsorbent pulp and a stabilized matrix of thermoplastic fibers. In a still further aspect, the liquid impervious layer desirably comprises a multiple layer laminate having at least one nonwoven web of thermoplastic fibers. As an example, the liquid-layered multiple layer laminate may comprise a spunbonded / meltblown / spunbonded laminate. As a further example, the multilayer laminate may comprise a microporous breathable film and a woven fabric. In a further aspect of the invention, the absorbent pad can have a contoured three-dimensional shape ta as, for example, a generally concave shape.
Brief Description of the DrawingsFigure 1 is a side view of a breastfeeding pad of the present invention with part partially cut out to reveal the cross section taken on line A-A 'of Figure 2.
Figure 2 is a top plan view of the breastfeeding pad of Figure 1.
Figure 3 is a top plan view of a breastfeeding pad of the present invention.
Figures 4 and 5 are views of joining patterns suitable for use with the present invention.
Figure 6 is a side view of an apparatus useful for making an absorbent pad of the present invention.
Figure 6A is a cross-sectional view of an apparatus of Figure 6 useful for making an absorbent pad of the present invention.
DefinitionsAs used herein, the term "non-woven fabric" "non-woven fabric" means a fabric having a structure of individual threads or fibers which are interlocked but not in an identifiable manner as in a tangled woven fabric. Non-woven fabrics or fabrics have been formed in many processes such as, for example, meltblowing processes, spinning processes, hydroentanglement of the carded and bound fabrics, and placement by air.
As used herein, the term "microfiber" means small diameter fibers having an average diameter of no more than about 10 microns In a preferred embodiment, the microfibers can have an average diameter of from about 0.5 microns to about 10 microns. Microfibers can include both melt blown fibers and / or fibers joined by fine spinning.
How it is used here, the term "spunbonded fibers" or "spunbonded fibers" refers to small polymer oriented diameter d fibers. The co-bound fibers are formed by extruding the melted thermoplastic material as filaments from a plurality of usually circular and fine capillary vessels of a spinning organ with the diameter of the extruded filaments then being rapidly reduced as, for example, indicated in FIG. U.S. Patent No. 4,340,563 issued to Appel, others, and U.S. Patent No. 3,692,618, issued to Dorschner et al.; in United States of America Patent No. 3,802,817 issued to Matsuk et al .; in the US patents of North America Nos. 3,338,992 and 3,341,394 issued to Kinney; in United States Patent No. 3,502,763 issued Hartman; in U.S. Patent No. 3,542,615 issued to Dobo et al .; and in U.S. Patent No. 5,382,400 issued to Pike et al. Spunbonded fibers are not generally sticky when they are deposited on a collecting surface and so often require an additional mechanical chemical bond to form a stabilized fabric. and integrated.
As used herein, the term "co-melt blown fibers" means fibers which are generally formed by extruding a melted thermoplastic material through a plurality of capillaries, usually thin circular as melted threads or filaments into the gas stream. at high speed, usually hot (for example, air) which attenuate the filaments of molten thermoplastic material to reduce its diameter, which can be a microfiber diameter. Then, the co-melt blowing fibers are generally carried by the gas stream at high speed and are deposited on a collecting surface to form a fabric of meltblown fibers disbursed at random. Such a process is described, for example, in United States Patent No. 3,849,241 issued to Buti et al., And in United States Patent No. 4,013,881 issued to Timmons et al., The entire contents of which is hereby incorporated by reference. which are incorporated herein by reference. Meltblown fibers are often microfibers which may be continuous or discontinuous and are generally tacky when deposited on a picking surface. As used herein, the term "multi-layer non-woven laminate" means a laminate comprising a plurality of webs. layers wherein at least one of the layers is a non-woven fabric. As an example, the laminates wherein some of the layers are spun bonded and some are co-melt blown such as a co-melt / spunbonded (SMS) spunbond / blown laminate and others as described in the US patent United States of America No. 4,041.20 granted to Brock et al .; in U.S. Pat. No. 5,169,706 issued to Collier et al .; in the patent of the United States of North America No. 5,145.72 granted to Potts and others; in U.S. Pat. No. 5,178,931 issued to Perkins et al .; and in United States Patent No. 5,188.88 issued to Timmons and others; the complete contents of which are incorporated here by reference. Such a laminate can be made by depositing the sequence on a movable forming band first a layer of spunbonded fabric, then a layer of melt blown fabric and finally another spunbonded layer and then joining the laminate in a manner described below. Alternatively, the fabric layers can be made individually, collected in rolls, and combined in a separate bonding step. The multiple layer laminates may also have several numbers of melt blown or multiple spunbonded layers in many different configurations and may include other materials such as (F), eg, SMMS, SM, SF, SFS, etc.
As used herein, the term "coform material" means composite materials comprising a stabilized matrix mixture of thermoplastic fibers and a second non-thermoplastic material As an example, co-material materials can be made by a process in which at least one meltblown matrix head is arranged near a conduit through which other materials are added to the fabric while it is being formed, other materials may be, for example, pulp, superabsorbent particles, cellulose and / or or short fibers The coform processes are described in commonly assigned U.S. Patent 4,818,464 Lau, in U.S. Patent No. 4,100,324 issued to Anderson et al., in the U.S. Patent. No. 5,284,703 granted to Everhar and others, and in the United States Patent of North America No. 5,350,624 issued to Georger and others, whose complex contents of the aforementioned references are incorporated herein by reference.
As used herein, a "superabsorbent" or "superabsorbent material" refers to an inflatable material and water, soluble in organic or inorganic water under favorable conditions, to absorb at least about 10 times s weight and, more desirably, at least about 20 times s weight in an aqueous solution containing 0.9 percent by weight of sodium chloride . Suitable organic materials for use as a superabsorbent material in conjunction with the present invention include, but are not limited to, natural materials, such as guar gum, agar, pectin and the like, as well as synthetic materials such as polymers of synthetic hydroge Such hydrogel polymers include, for example, the alkali metal salts of polyacrylic acids, polyacrylamides, polyvinyl alcohol, ethylene, maleic anhydride copolymers, polyvinyl ethers, methyl cellulose, carboxymethyl, hydroxypropyl cellulose, polyvinyl d morpholinone, and polymers and copolymers of vinyl sulfide acid, polyacrylates, polyacrylamides, polyvinyl pyrrolidone and the like. Other suitable polymers include the hydrolyzed acrylonitrile grafted starch, the acrylic acid grafted starch, and the isobutylene maleic anhydride polymers mixtures thereof. The hydrogel polymers are preferably crosslinked slightly to make the materials essentially insoluble in water. Cross-linking can, for example, be achieved by irradiation or by covalent, ionic, Van der aals hydrogen bonding. The superabsorbent materials may be in any form suitable for use in the absorbent compositions including particles, fibers, flakes, similar spheres. Typically the superabsorbent material is present within the absorbent body in an amount of from about 5 to about 95% by weight based on the total weight of the absorbent body. The superabsorbents are generally available in particle sizes varying from about 20 to about 1000 microns. An example of the commercially available superabsorbent is SANWET IM 3900 available from Hoesch Celanese located in Portsmouth, Virginia and DRYTECH 2035L available from Dow Chemical Company, located in Midland, Michigan.
As used herein, the term "polymer generally includes but is not limited to homopolymers, copolymers, such as, for example, block, graft, random and alternating copolymers, terpolymers, etc., and mixtures and / or modifications thereto In addition, unless specifically limited otherwise, the term "polymer will include all spatial configurations of the molecule. These configurations include, but are not limited to, isotactic, syndiotactic and / or random symmetries. .
As used herein, the term "monocomponent fiber" refers to a fiber formed from one or more extruders using only one polymer. This does not want to exclude fibers formed from a polymer which have added small amounts of additives for coloring, antistatic properties, lubrication, hydrophilicity, etc. These additives, for example, titanium dioxide dye coloration are generally present in an amount of less than 5 percent by weight and more typically of about 2 percent by weight.
As used herein, the term "multi-component fibers" or "conjugated fibers" refers to fibers which have been formed from at least two extruded polymers of separate extruders but which are spun together to form a fiber. The bicomponent fibers refer to a common specific class of multicomponent fiber wherein the fibr comprises two distinct components. The polymers are arranged in distinct zones placed essentially in a constant form across the cross section of the fibers and extend continuously along the length of the fibers. The configuration of such fibers may be, for example, a sheath / core arrangement. where one polymer is surrounded by another or can be a side-by-side arrangement, a pastel arrangement or an arrangement of "islands-in-the-sea". The conjugated fibers are taught in U.S. Patent No. 4,010,820 issued to Kaneko et al .; in U.S. Patent No. 4,795,668 issued to Kruege et al .; and in the United States Patent of North America No. 5,336,552 issued to Strack et al. Multi-component fibers are also taught in U.S. Patent No. 5,382,400 issued to Pike and others can be used to produce crimps in the fibers by pulling the multi-component fibers with heated air, the complete contents of the patent before mentioned is incorporated herein by reference. For bicomponent fibers, polymers can be present in proportions of 75/25, 50/50, 25/75 or any other desired proportions. Fiber may also have forms such as those described in United States Patent No. 5,277.97 issued to Hogle et al .; in U.S. Pat. No. 5,466,410 issued to Hills; and U.S. Pat. Nos. 5,069,970 and 5,057.36 to Largman et al., which disclose non-conventional fibers.
As used herein, the term "multi-constituent fibers" or "biconstituent fibers" refers to fibers which have been formed from at least two extruded polymer and the same extruder as a mixture. The term "mixture" is defined below. The biconstituent fibers n have the various components of the polymer arranged in different zones constantly placed across the cross-sectional area of the fiber and the various polymers are not usually continuous along the entire length of the fiber, in view of this , they usually form fibrils or protofibrils, which start and end at random.
As used herein, the term "mixture" means a combination of two or more polymers while the term "alloy" means a subclass of mixtures wherein the components are miscible but not compatibilized.
As used herein, the term "ultrasonic bonding" means a process carried out, for example, by passing the fabric between the sonic horn and the anvil roll as illustrated in the United States Patent of North America.
No. 4,374,888 granted to Bornslaeger.
As used herein "knit together" means the joining of one or more fabrics with a pattern of discrete joining points. As an example, thermal point bonding often involves passing a cloth or weave of fibers that are to be joined between a pair of heated bonding rolls. One of the bonding rolls is usually, although not always patterned in some way so that the entire fabric is not bonded across its entire surface, and the second roll or anvil roll is usually flat. As a result of this, several patterns have been developed for calendering rolls for functional reasons as well as aesthetics. An example of a pattern having points and is the Hansen Pennings pattern or "H &P" with about 30% of united area with about 200 joints / square inch as taught in US Pat. No. 3,855,046 granted to Hansen and Pennings. The H & P pattern has square point bolt joint areas where each per has a side dimension of 0.038 inches (0.965 mm), a gap of 0.070 inches (1,778 mm) between the bolts, and a joint depth of 0.023. inches (0.584 mm). The resulting pattern has a bound area of about 29.5%. Another typical point union pattern is the Hanse union patternExpanded Pennings or "EHP" which produces a joint area of 15 with a square bolt having a side dimension of 0.03 inches (0.94 mm), a 0.097 inch bolt spacing(2,464 mm) and a depth of 0.039 inches (0.991 mm). Another typical point union pattern is designated "714" and has square bolt joint areas where each bolt has a side dimension of 0.023 inches, a spacing of 0.06 inches (1.575 mm) between the bolts, and a joint depth. of 0.033 inches (0.838 mm). The resulting pattern has a united area of about 15%. Yet another common pattern is the star pattern in C which has a bound area of about 16.9%. The star pattern in C has a "corduroy" design or a transverse direction interrupted by shooting stars. Other common patterns include a diamonds pattern co slightly decentered and repetitive diamonds with around d an area of 16% union and a wire weave pattern having generally alternating perpendicular segments co around a united area of 19%. Typically, the percent bond area varies from about 10% to about 30% of the area of the fabric laminated fabric. The knit union can be used to hold the layers of a laminate together and / or to impart integrity to the individual layers by joining the filaments and / or fibers within the fabric.
As used herein, air bonding or " " means a process of joining a non-woven multicomponent fiber fabric in which the air is hot enough to melt one of the polymers from which the fibers are made of the fabric when forced through the fabric. The air speed is between 100 and 500 feet per minute and the dwell time can be prolonged as 6 seconds. The melting and l resolidification of the polymer provides the bond. The union through air has a relatively restricted variability and since the union through air ( ) requires the melting of at least one component to achieve the union, this is often restricted to fabrics with two components such as bicomponent fibers or those which include a sticker. At the junction through air, the air having a temperature above the melting temperature of a component and below the melting temperature of another component is directed from a surrounding cover, through tissue and up to a perforated roller that holds the fabric Alternatively, the air binding device can be a flat arrangement where the air is directed vertically downwards on the fabric. The operating conditions of the two configurations are similar, the primary difference being the geometry of the fabric during joining. The hot air melts the lower melt polymer component and thus forms bonds between the filaments and the contact points to integrate the fabric.
As used herein, the term "autogenous bond" refers to the union between discrete parts and / or surface independently of external additives such as adhesives, solders, mechanical fasteners and the like. As an example, the multiple bicomponent fibers can be autogenously bonded through the air union whereby the interfiber bonds develop at the contact points of the fiber.
As used herein, the term "rib" meant a relief or flange on a fabric. An example of a rib and one of the parallel ridges on the surface of a cloth ta like corduroy.
As used herein, the term "liquid impervious" means that a film, laminate or other fabric is relatively impervious to the transmission of liquids, having a hydro head of at least about 10 cm. The hydro head as used herein refers to a measure of the liquid barrier properties of a fabric. The hydro head test determines the height of the water (in centimeters) that the fabric will hold before a predetermined amount of liquid passes through it. A fabric with a higher hydro head reading indicates that it has a greater barrier to liquid penetration than a fabric with a lower hydro head. The hydro head test can be carried out in accordance with the Federal Test Method Standard 191A, Method 5514 or using a hydrostatic head tester from Mari Enterprises, Inc., of Concord, North Carolina. Unlike Method 5514, when a hydro head test is used, it is subjected to a standardized water pressure, increased at a constant rate until the first sign of runoff appears on the surface of the fabric in separate areas. (The runoff on the edge adjacent to the clamps is ignored). Non-supported fabrics, such as a thin film can be held to prevent premature rupture of the specimen.
As used herein, the term "ability to breathe" refers to a material which is permeable to water vapor having a minimum WVTR (water vapor transmission rate) of at least 300 g / m2 / 24. hours. However, the frequent applications of breathable barriers desirably have higher water vapor transmission rates and the breathable barriers of the present invention can have water vapor transmission rates exceeding 800 g / m2. / 24 hours, 1500 g / m2 / 24 hours, or more than 3000 g / m2 / 24 hours. The water vapor transmission rate can be measured according to the ASTM standard test method for water vapor transmission of materials, designation E-96-80, as modified below and the results are reported in grams / square meter / 24 hours. Circular samples measuring three inches in diameter were cut from one of the test materials and a control which was a piece of CELG RD1 ™ 2500 film from Hoechst Celanese Corporatio of Summerville, New Jersey. The film CE1? G? RDM? RCA 2500 is a microporous polypropylene film. Three samples were prepared for each material. The test plate was a patent leather Vapometer number 60-1 distributed by Thwing-Albert Instrumen Company, of Philadelphia, Pennsylvania. About 100 milliliters of water were poured into each Vapometer tray and individual samples of the test materials and control material were placed through the open top portions of the individual trays. The bolted flanges were pressed together to form a seal along the edges of the tray, leaving the associated test material or control material exposed to the ambient atmosphere over a circle of 6 centimeters in diameter having an exposed area of approximately of 33.17 square centimeters. The trays were placed in a forced air oven at 32 ° C for one hour to equilibrate. The furnace was a constant-temperature furnace with an external air circulation through it to prevent the accumulation of water vapor inside. An adequate forced air oven is, for example, a Blue M Power-O-Matic 6 furnace distributed by Blue M Electric Company, of Blue Island, Illinois. When the balance was complete, the trays were removed from the oven, weighed and immediately returned to the oven. After 24 hours, the trays were removed from the oven and weighed again. The preliminary test water vapor transmission rate values were calculated with the equation (I) given below:(I) Test WVTR = (weight loss grams over 24 hours) x 315. g / m2 / 24 hoursThe relative humidity inside the oven was not specifically controlled.
Under the prescribed conditions of 32 ° C and ambient relative humidity, the water vapor transmission rate for the control CELG RD "^^ 2500 has been defined as being 5000 g / m2 / 24 hours. The sample of control was run with each test and the preliminary test values were corrected to establish conditions using equation (II) given below:(II) WVTR = (WVTR test / WVTR control) x (5000 g / m2 / 24 hours)Description of the Preferred ModalitiesWith reference to Figure 1, a breastfeeding pad 10 is shown comprising a soft liquid permeable layer 12, an absorbent core 18 and a barrier laminate impermeable to liquid 24. The breastfeeding pad 10 has a generally concave shape so that The pad 10 can be placed between the breast and the brassiere and is easily conformed to this. The liquid permeable layer 12 is typically placed on one side of the breast, desirably centered around the nipple, so that the barrier laminate 24 is adjacent to the brassiere. Fluid runoff from the sinus will be pulled or transmitted through the liquid permeable layer 12 and absorbed by the absorbent core 18. However, with reference to FIGS. 1 and 2, the absorbed fluid will be retained within the absorbent core as this will not pass through the outer layer impervious to liquid 2 nor will it leak through seal 34 of edge 32.
Existing personal care items often use a body-to-body or liquid-permeable layer which has a rough, unpleasant plastic feel. This is undesirable since it reduces the comfort of the person using the pad. Therefore, the face-to-face or liquid-permeable layer of the present invention desirably comprises a material with a good tactile feel, such as, for example, a non-woven fabric of multi-component fibers. In order to retain the desired level of liquid permeability, multicomponent fibers must have a high hollow spacing and a basis weight less than about 50 g / m2 and more desirably between about 1 g / m2 and 35 g / m2. Desirably, the liquid permeable layer comprises a nonwoven fabric such as, for example, continuous spunbonded fiber fabrics, carded and bonded fabrics, short fiber fabrics and / or hydroentangled fabrics. Suitable materials of the liquid permeable layer include thermoplastic polymers such as polyolefins, polyamides (nylons), polyesters and copolymers and mixtures thereof. The multi-component fibers allow the use of two or more polymers and, therefore, the "hand" or feel of the non-woven fabric can be improved by selecting at least one polymer with a good feel. The second polymer, compatible and immiscible with the first, can comprise a polymer with better tensile or resistance properties (in relation to the first polymer). A particularly desired multiple component fiber may comprise one or more components of a polyethylene polymer and one or more components of a polypropylene polymer. As an example, in one embodiment the liquid permeable cap may comprise either bicomponent crimped or non-crimped yarns having a polyethylene polymer sheath and a polypropylene polymer matrix or core.
The skin-facing or side-to-liquid-permeable body 12 may comprise either a hydrophilic or hydrophobic material, additionally the skin-facing or inner layer may comprise both hydrophobic hydrophilic components which desirably give the layer a charact general hydrophilic. As an example, the inner layer can comprise a non-woven fabric comprising a mixture of hydrophilic and hydrophobic fibers. The side layer to the inner skin permeable to the liquid preferably promotes the transfer of the liquid out of the skin and does not retain fluid in order to improve the feeling of the pad against the skin. Many thermoplastic polymers, including polyolefins, are inherently hydrophobic. Therefore, in those cases where it is desired that the inner liquid permeable layer be hydrophilic the fibers may require treatment to impart a wettability or hydrophilic properties to the fibers. Methods for treating the polymers to make them hydrophilic are discussed in U.S. Patent No. 4,920,168 issued to Nohr others.; in the patent of the United States of America No.3,973,068 granted to Weber; and in the patent application of the United States of North America series No. 08 / 565,261 granted Pike et al. In addition, known surfactants can be used to impart wettability to the fibers such as, for example, octylphenoxy polyethoxy ethanol which is commercially available under the trade name TRITON X-10 from Union Carbide of Danbury, Connecticut. The bicomponent polyolefin fiber fabrics desirably comprise from about 2% to about 10% surfactant which is added to the polymer prior to extrusion. Once formed, the surfactant migrates to the surface of the fiber imparting wettability to the fiber.
In addition, in order to impart the desired integrid to the side of the body or to the skin facing layer, the non-woven fabric of the multicomponent fibers can be joined together, such as, for example, by knitted fabrics which are knitted together in an autogenously bonded fabric. The union can be achieved by an air-binding ( ). A thermal point joint, an ultrasonic joint, or other known joining techniques. In order to improve the feel of the article, the knitted fabrics desirably employ a repeating pattern of relatively small joining points. Examples of suitable patterns described above with respect to point bonding are also shown in Figures 4 and 5. Employing such a pattern is believed to create a fabric texture more pleasing to the touch, for example, a hand improvedAdjacent to the liquid permeable layer 12 is an absorbent core which may comprise one or more layers capable of absorbing aqueous solutions or suspensions such as milk for breastfeeding. The absorbent core 1 desirably comprises a combination or blend of thermoplastic fiber and an absorbent material. The absorbent core may comprise coform materials even though it may be feasibly used according to the present invention other suitable absorbent fabrics comprising a combination of thermoplastic fibers and absorbent material. The exemplary coform materials are described in United States Patent No. 5,284,703 issued to Everhart et al., Commonly assigned; in U.S. Pat. No. 5,350,624 issued to Georger et al .; and in the patent of the United States of North America No. 4,100.32 granted to Anderson et al .; whose complete contents of which are incorporated herein by reference. Suitable absorbent materials include, but are not limited to, fibrous organic materials such as ligneous woody pulp such as cotton, rayon, recycled paper, pulp eraser and also include inorganic absorbent materials such as superabsorbent materials and / or polymer fibers treated.
The absorbent core desirably has sufficient absorbent material to absorb at least about 3 g of liquid and desirably from about 3 g to about 50 g of liquid. In an incorporation the absorbent core 18 may comprise at least about 34 g / m2 of coform material, and more desirably comprises from about 60 g / m2 to about 340 g / m2 of coform material. In addition, the coform material preferably comprises from about 10% to about 35% by weight of thermoplastic fiber. As an example, the coform material can comprise the fibers blown with polypropylene melt and the fibers of wood pulp. As a further example, the absorbent material can be maintained in a thermoplastic short fiber fabric such as, for example, carded and bonded fabrics or placed by air. The absorbent core may comprise one or more layers and the additional absorbent materials may be dispersed within or between the one or more layers to increase the absorbency as desired. As an example, United States Patent No. 4,784,892 issued to Store et al. Teaches an absorbent material of blown fibers co-melting with an absorbent fibrous material (eg wood pulp) as well as a superabsorbent dispersed therein.; The contents of the aforementioned application are incorporated there by reference. In addition, the absorbent core may comprise an absorbent layer of thermoplastic fibers and absorbent material wherein the percent by weight of the thermoplastic fibers to the absorbent fibers varies or the pore size varies through the depth of the fabric.
The absorbent core is positioned between the liquid permeable cap 12 and an outer liquid impervious layer such as a multilayer nonwoven laminate 24. The multilayer nonwoven laminate is relatively impervious to the transmission of liquids and must have a non-woven laminate. hydro head of at least about 10 centimeters or more and even more desirably, has a hydro head in excess of about 20 centimeters. In one embodiment, the multilayer nonwoven laminate may comprise a laminate of a first layer comprising at least one layer of 6 g / m2 d microfiber thermoplastic polymer and a second layer comprising at least one layer of 8 g / m2 of fibers joined together by spinning; more desirably the multiple layer laminate comprises from about 10 g / m2 to 25 g / m2 of meltblown fibers and 15 g / m2 to about 34 g / m2 of fiber joined by spinning. With such a two-layer laminate the microfiber will preferably face the absorbent core and the spunbonded fibers will face the opposite outer or distal side of the pad. The liquid impermeable layer may also include the additional layers and desirably the total basis weight of the barrier laminate is less than about 102 g / m2 and even more desirably between about 20 g / m2 and about 60 g / m2. In a further embodiment multi-layer laminate may comprise a spun-bonded / meltblown / spunbond (SMS) laminate. Laminates of lower basis weight, with good barrier properties as described in commonly assigned United States Patent No. 5,492,751 to But et al., The entire contents of which are incorporated herein by reference, are believed to be which are suitable for use in the present invention. Further, in order to provide a breastfeeding pad with an improved overall feel the outer layer of multilayer laminate may comprise a multilayer fiber fabric, similar to those described above in relation to the skin facing layer or the skin layer. inside. However, in order to help reduce slippage of the breastfeeding pad, an outer layer having a sticky or rough surface may be desirable.
In a further embodiment the multilayer woven laminate or the barrier laminate may comprise a nonwoven laminate / microporous film. A particularly useful barrier comprises a stretched and breathable filled micropore film. Such films are typically filled with particles and then crushed and / or stretched to form a network of fine pores through the film. The network of film pores allows gas and water vapor to pass through the film while acting as a barrier to liquids and particulate matter. The amount of filling within the film and the degree of stretch was controlled as to create a network of micropores of a size and / or frequency to impart the desired level of breathability to the fabric. A suitable microporous film is described in U.S. Patent No. 4,777,083 issued to Sheth. An exemplary stretched filled film is also described in commonly assigned patent application WO 95/16562 and in US Pat. No. 5,695,86 issued to McCormack which describes a stretched filled film comprising a polymer of polyolefin predominantly lines, a binding agent and about 30 to 80% po weight of calcium carbonate, which can be stretched to impart the ability to breathe to the film; the aforementioned application and the patent are incorporated herein by reference. The stretched film can then be laminated to a woven fabric to create a laminate which takes advantage of the strength and integrity of the non-woven fabric and also of the barrier properties of the stretched film. An additional suitable laminate is disclosed in the commonly assigned patent application WO 96/19346 granted to McCormack et al., And the United States patent application of North America Series No. 08 / 882,712 granted to McCormack et al., Which employs a multi-layer film having layers of thin skin to provide an improved bond to a woven n-support layer; The full contents of the aforementioned application are incorporated herein by reference. The film / n-woven laminates allow thermal bonding of the laminate to the absorbent core and / or to the skin-side layer while providing an article with good breathability and excellent barrier properties.
The multiple layers of breastfeeding pad are preferably joined together along the edge 32 of the nursing pad 10. The multiple layers may be joined such as, for example, thermal bonding, ultrasonic bonding, mechanical crimping, sewing and / or joining adhesively. Desirably, the layers are joined using a method which creates a seal by causing the polymer to flow into one or more thermoplastic laminate fibers. The joining of the individual layers of the absorbent pad to create a seal can be achieved through various means such as, for example, through bonding using ultrasonic or thermal energy and combination with pressure. However, it is important that the joining method does not destroy the fall and general sensations of the individual layers. Excessive ultrasonic or thermal energy and excessive pressure can create a relatively rigid and not comfortable cushion with a poor touch. As one of the layers includes the thermoplastic polymers there, the bonding along an edge 32 acts to create a seal which reduces and / or prevents fluid from slipping out of the pad itself. The edge may be joined with a continuous seam, as shown in Fig. 2, or a series of closely spaced knit seams 38 such as, for example, s shown in Fig. 3. Desirably, the seal or seam 34 is placed on the edge to about one centimeter of the outermost edge of the pad. In addition, it is possible that the absorbent core does not extend completely to the edge of the pad 32 so that the seal 34 comprises a bond between the barrier layer 24 and the side-to-body layer 12. In addition, it is also possible that the liquid-permeable body side layer is wrapped around the edge from side to side and over the barrier layer.
In order to improve the ability of the breastfeeding pad to conform to the breast and the brassiere, a breast pad desirably has, with respect to the side to the body, a generally concave shape. Desirably, the breastfeeding pad comprises an essentially circular concave disk having a diameter of from about d 5 to about 15 centimeters and a height (h) of from about 0.6 centimeters to about 7 centimeters. However, the concave breast pad may comprise other shapes and molded shapes, such as, for example, a teardrop shaped pad generally. In addition, with reference to Figure 2, the breastfeeding pad may have a plurality of ribs 36 extending radially d from about the center of the pad. The ribs inside the pad can give the pad improved resistance to bagging in use. Desirably, the pads extend along the outside of the liquid impervious layer 24. However, imparting the ribs to the absorbent material and / or the liquid permeable layer can advantageously improve the transmission of the liquid to the outer portions. of the absorbent core.
The three-dimensional shape of the pad can be imparted by one of several methods. Desirably, the breastfeeding pad is molded or thermoformed into a desired shape. The breastfeeding pad can be thermoformed in a manner to retain the good smoothness and feel of the thermoplastic layers, as described in United States Patent No. 5,695,376; in patent application No. 08 / 303,786 filed on September 9, 1994 to Data others and in United States Patent Application No. 08 / 176,594 issued to Pike et al., filed on January 3, 1994; whose contents of the patent and of the aforementioned applications are incorporated herein by reference. The thermoforming of the breastfeeding pad creates a self-attached tel, which has the desired three-dimensional shape while having excellent flexibility and a good feel. An article with a superior tactile feel can be achieved when an article is thermoformed using the multi-component fiber fabrics in the multi-layer laminate of the liquid permeable layer and / or the barrier laminate. With reference to figures 6 and 6A, the shaped cylinders 50 and 52 can be used to thermoform the absorbent pad 10 and simultaneously impart a seal to the edge of the pad. An angled edge or raised ring 5 on the first cylinder 50 can be adapted to impart the ultrasonic energy to the fabric, thereby creating a sealed edge for the absorbent pad 10 by pressing the first and second cylinders, 50 and 52 against the 10. In addition, both cylinders can be hollow with the cylinder 52 having a foraminous surface 58 to allow the heated air 5 to flow from the first cylinder 50 to the second cylinder 52 through the fabric 10. The duration, pressure and The energy imparted to the fabric can be varied to achieve the desired degree of bonding and the overall integrity of the shaped pad. In addition, the breastfeeding pad can be molded into the desired concave shape through the use of one or more heated plates and / or molds. Desirably, the plates may comprise a female base and a male forming plate having a flattened ring to impart the desired bond pattern to the edge of the pad. One or both of the plates can be heated even though desirably one or both of the plates are heated only on the perimeter of the pad. The layers comprising the pad can be placed between the barrier plates on one side of the female base. The plates can then be brought together at the desired pressure, temperature and duration to join the layers together and impart an edge seal to the pad. Other methods for forming the shaped multiple layer structure can also be used in conjunction with the present invention as long as they retain the good fall and feel of the individual materials and do not otherwise destroy the comfort or otherwise comfort or function of the fabric. l pad.
Although the invention has been described in detail with respect to the specific embodiments thereof, particularly the examples described therein, it will be apparent to those skilled in the art, that various alterations, modifications and other changes may be made without departing from the spirit. and scope of the present invention. It is attempted therefore that all such modifications, alterations and other changes may be encompassed by the claims.