EP1841380A2

EP1841380A2 - Superabsorbent pad

Info

Publication number: EP1841380A2
Application number: EP05776554A
Authority: EP
Inventors: Bruce Fine; David Hill
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-07-19
Filing date: 2005-07-19
Publication date: 2007-10-10
Also published as: WO2006020213A3; EP1841380A4; WO2006020213A2

Abstract

An absorbent article comprises an absorbent core, such as cellulose and a superabsorbing material, and a bicomponent fiber layer, the core being attached to the layer but not completely surrounded by it. The core and the layer absorb fluid. The superabsorbent material is present in an amount typically less than about 70% by weight, based on total weight of the core's materials. The article in the form of a pad may be utilized to absorb bodily fluids, such as in dental applications. In one embodiment, the superabsorbent material is an acrylate copolymer, the bicomponent fiber comprises, by weight, about 35% polypropylene and about 50% polyethylene, and the article has a free swell of approximately 50-75 grams of fluid per gram of absorbent pad; this amount is substantially greater than the standard sized cotton roll used in dental applications. Also disclosed are methods of using the article and the pad.

Description

SUPERABSORBENT PAD

CROSS-REFERENCE TO RELATED APPLICATIONS.

This application claims the benefit of United States Provisional Patent Application Ser. No.: 60/589,082, filed 19 July 2004, the contents of which are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION.

An embodiment of the present invention is a pad that has superabsorbent properties, and which pad comprises a core including a fibrous superabsorbing material, and outer portions of a bicomponent fiber. Regions of the core are exposed to the environment because the pad does not have to be enveloped to maintain its superabsorbent properties and to retain the superabsorbing material therein. Embodiments of the present invention have general application where superabsorbency properties are desired, and have particular application in clinical fields such as the dental, medical or veterinary areas.

BACKGROUND OF THE INVENTION.

There is a general need for materials capable of absorbing liquids of various types. This can range, for example, from absorbing liquids such as water that may have spilled in a kitchen; to absorbing industrial chemicals such as organic solvents and the like; uses for feminine hygiene; uses for disposable diapers; and, in clinical areas, to absorb bodily fluids ranging from blood, plasma, saliva, sweat, urine, purulent exudate and the like. However, although the following sections will focus on the use of absorbent materials in the dental fields, it is to be understood that these principles can be applied to a variety of other, non-dental areas. Similarly, although reference may be made to use of embodiments of the invention with humans, the use of such embodiments in industrial and veterinary procedures is also specifically considered within the scope of the invention.

Superabsorbing materials are known, and are generally considered to be materials that have the ability to absorb and to retain large quantities of water or other aqueous solutions. Initially, superabsorbing materials were synthesized from starches that were chemically modified, cellulose, and one or more of several hydrophilic polymers that have a great affinity for water. Among these hydrophilic polymers are polyvinyl alcohols, and polyolefins, such as a poly(ethylene oxide). These polymers are water-insoluble, but are swellable in water after they have been either chemically or physically cross- linked. Superabsorbent materials have become components of several absorbent articles, such as, but not limited to, use in disposable diapers, feminine hygiene products, wound dressings, and dental applications for controlling flow of saliva from the parotid glands.

In the dental area, present types of disposable, non-mechanical, products have very limited fluid absorption (for fluids such as, for example only, saliva, water, or blood) unless these products are attached to some type of a suction device. There are 3 main types of these non-suction saliva absorbers.

1 - "Cotton rolls", to be defined in a later section, are commonly used under the tongue, in the maxillary buccal (cheek) vestibule or in the mandibular buccal fold; 2 - Flat, triangular, arrowhead or various other types and shapes of absorbers commonly used against the buccal mucosa; and 3 - "Cotton" gauze or sponges which are generally used mainly during surgical procedures. These are commonly referred to as "sponges" or "2 by 2s", or "3 by 3s" etc. (generally referring to the size of the material). These types of sponges are not generally used as a saliva absorber in such "typical" dental procedures as prophylaxis, scaling, or tooth reconstruction or restoration.

The dentist's primary saliva absorber is the "cotton roll", which in some cases nowadays may be a misnomer because fibers other than cotton may be used in the product. "Cotton rolls", while containing one or more materials which are not cotton, such as cellulose, rayon, polyolefins or other synthetic materials, however do not contain any superabsorbent materials. The absorption capacity of these "cotton rolls" is limited to about 7.95 grams of water per gram of cotton roll. (The #2 cotton roll is the size of cotton roll used commonly used in dentistry.)

The affinity of the fibers that comprise the cotton roll for the absorbed fluid is believed to be due to a weak physical force, such as capillary action, so that when pressure is applied to a cotton roll containing an absorbed fluid, the cotton roll releases the fluid quite readily. Generally, and in these inventors' experience, most dental procedures cannot be completed using a single cotton roll. Due to the nature of today's dental restorative procedures (for example, bonding artificial materials such as composites and porcelain to tooth structures), isolation of the area is an important factor to achieving long term durability, and reduction of any side effects that the patient may experience, such as sensitivity to heat, cold or other sensations.

During certain dental procedures, tissue retraction can be problematic, and there is a possibility that tongue and buccal tissues can be traumatized during various dental procedures.

Another problem is that rotary instruments, such as a dental handpiece, can become entangled in most existing saliva absorbers. Existing superabsorbent saliva absorbers require some type of envelopment to prevent spilling of the superabsorbent.

The following is a summary of the prior art and its limitations:.

1. "Cotton Rolls" a. Composed of cotton fibers, cellulose, synthetic fibers, or a combination of one or more of such fibers. b. There are two types of cotton rolls: Braided and Smooth. c. Generally circular in cross section, with the cotton rolls most commonly employed having a length of approximately 33 mm and a diameter of approximately 6-7 mm. d. There is only one type of cotton roll on the market whose manufacturer claims that the cotton roll will not entangle a dental rotary device. e. Absorb approximately 7.95 grams of water per gram of cotton roll. f. Limitations: (1) Most procedures cannot be completed without changing out the cotton roll due to its limited absorbency. (2) The process of changing out the cotton roll breaks the isolation and risks contamination of the surgical site. (3) Squeezing of the hydrated cotton roll when removing the cotton roll from the mouth releases fluid because of the weak forces of attraction between the fluid and the fibers. (4) Retraction of tissues is limited by the diameter of the cotton roll being used, and inadequate retraction occurs in a number of situations.

2. Shaped absorbent pads such as DRI-ANGLEs®, DRI-AIDs™, or the like. a. Range in thickness from 1-22 mm; are generally flat, with a triangular or other shape. b. Generally made of cellulose. Some types of pads also have a side that is reflective, to provide additional light to the side being treated. c. Designed to be placed directly against the buccal mucosa. d. Absorbs under 3 m I (based on absorbancy of the larger of the two sizes of pad). e. Limitations: (1 ) Placement is limited to use at buccal mucosa. (2) Limited absorption capacity, requiring changing out during procedures, with inherent contamination risks from saliva or blood while changing out. (3) Retraction of tissue is limited to the thickness of the product being employed. (DRI-ANGLE® is a registered trademark of Dental Health Products of New York, (Youngstown, NY), for their brand of paper pulp wedges to be placed within a patient's mouth during dental work. U.S. Pat. No. 3,468,030 issued to Peyser et al. discloses a dental device of a generally triangular shape to serve as a mouth prop blocking the parotid salivary gland and to provide absorption. The device disclosed bears a marked similarity to the DRI-ANGLE® product.)

(DRI-AID™ is a trademark of Young Dental Mfg. Co., Earth City, MO, for their brand of an absorbent pad for dental procedures.)

3. DRYTIPS® a. Approximately 2 mm thick, with a flat arrowhead shape; used to control saliva flow from the parotid glands and keeping the cheek dry. b. Comprise a 3 layer laminate with outer 2 layers enveloping an inner layer of superabsorbent material, as described below. (1) Clear impervious layer (2) Superabsorbent layer (3) Permeable net layer c. Absorbs approximately 6 ml. d. Limitations: (1) Placement is limited to use at buccal mucosa. (2) Use limited to dentistry. (DRYTIPS® is a registered trademark (owned by Molnlycke Aktiebolag LLC, Goteborg, Sweden) for their brand of professional dental products, namely plasters, bandages and compresses for absorbing saliva and other human secretions.)

4. Rubber Dam a. Device used to isolate a surface and not absorb any fluid.

5. Devices attached to outside hookups (vacuum, electrical, etc.) a. Saliva ejector b. Denta-pop (brand of suction device for dental use, saliva ejectors and tongue retraction). c. ISOLITE (ISOLITE was a registered trademark, now abandoned, of lnnerlite Corp, Santa Barbara CA for their brand of suction devices for dental use, saliva ejectors and tissue, tongue and cheek retractors.)

An embodiment of the invention is a superabsorbent pad designed to be placed adjacent to the major salivary glands in the maxillary buccal vestibule and under the tongue. Because of the size and geometry of an exemplary embodiment, placement of these pads in the oral cavity is virtually unlimited.

It is comprised of a nonwoven matrix of fibers that do not allow the superabsorbent to migrate out of it and therefore does not require any type of envelope or membrane. An exemplary pad is approximately 8 mm thick by approximately 12 mm wide and approximately 35 mm in length, and in the shape of a rectangular bar, which may or may not have a radius placed at the corners.

The inventive pad absorbs about 3 times the amount of fluid when compared to the "standard" (#2 size) cotton roll which it is designed to replace, when measured in a free swell test. To absorb this amount of fluid, the pad must expand. The expansion due to its construction is limited primarily to one dimension; the thickness increases. This is quite advantageous for retraction because the pad will push tissue out of the way. If the pad is hydrated while the tissue is otherwise retracted the pad will hold the tissue out of the way rather than having to fight against the forces of the tissues which could limit the amount of expansion.

Superabsorbent fibers in contrast to other fibers have a very strong attraction/reaction to fluids. The superabsorbent fibers will not release the fluids that have hydrated them unless forces are applied that are not usually present during the normal course of dental treatment.

The fibers used in the pad do not entangle any dental instruments, most specifically rotary instruments.

Products that include superabsorbing polymers therein generally utilize an outer membrane or similar type of barrier structure to keep the superabsorbing polymer within the matrix of the product. Embodiments of the present invention, in contradistinction, utilize a superabsorbing polymer which does not require the presence of an external membrane or similar type of barrier structure. Thus, absorbent articles, such as pads, prepared with this superabsorbent can be positioned directly in contact with the fluid to be absorbed, and once wet, will retain the absorbed fluid; for typical uses, the absorbent pad will not deteriorate due to leakage of the superabsorbing polymer from the product's matrix.

BRIEF SUMMARY OF THE INVENTION.

An object of the present invention is to provide an absorbent article for absorbing fluids which comprises a core including a superabsorbing material, the core having sides and ends which are exposed to the external environment, eliminating the need for an additional member to envelope the sides and ends of the core to retain the superabsorbing material therein. Another object of the present invention is to provide an absorbent article which can have numerous applications ranging from use in personal care and consumer products, industrial and clinical applications.

Another object of the present invention is to provide an absorbent article that can be used in clinical applications in the dental, medical and veterinary fields.

Still another object of the present invention is to provide an absorbent article that can be used for retraction of a surface, such as tissue.

Yet another object of the present invention is to provide a method for retracting tissue using an article of absorptive material, the method comprising using a superabsorbing material retained within the matrix of the article in the absence of a member which envelopes the outer surface of the superabsorbing material.

An embodiment of the present invention is an absorbent article comprising an absorbent core, such as cellulose and a superabsorbing material, and a bicomponent fiber layer, the core being attached to the layer but not completely surrounded by it. The core and the layer absorb fluid. The superabsorbent material is present in an amount typically less than about 70% by weight, based on total weight of the core's materials. The article in the form of a pad may be utilized to absorb bodily fluids, such as in dental applications. In one embodiment, the superabsorbent material is an acrylate copolymer, the bicomponent fiber comprises, by weight, about 35% polypropylene and about 50% polyethylene, and the article has a free swell of approximately 50-75 grams of fluid per gram of absorbent pad; this amount is substantially greater than the standard sized cotton roll used in dental applications. Further embodiments of the present invention are methods of using the article and the pad.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS.

Fig. 1 is a perspective view of a representative prior art "Cotton roll".

Fig. 2 is a perspective view of an embodiment of the present invention when dry.

Fig. 3 is a side view of an embodiment of the present invention when wet.

DETAILED DESCRIPTION OF THE INVENTION.

A representative prior art "cotton roll" 10 is illustrated in Fig. 1 , wherein it can be seen that this "typical" cotton roll, (commonly referred to as a size 2 cotton roll) has a generally circular cross section, a diameter of approximately 6-7 mm. and a length of approximately 33-35 mm. Cotton rolls are generally manufactured using cotton fibers, cellulose, synthetic fibers, such as rayon, nylon or various polyolefins, or a combination of one or more of such fibers. Regardless of the type of fiber with which a "cotton roll" is manufactured, these articles will be referred to as cotton rolls, even if it does not contain any cotton. The size cotton roll illustrated in Fig. 1 is reported to have an absorbent capacity of approximately 3.5 ml of fluid.

An embodiment of the present invention is an absorbent pad (or absorbent article, or pad) 100 (Fig. 2), which in this embodiment has a rectangular configuration. It is to be understood that configurations other than rectangular are meant to be included within the scope of this invention, and this includes configurations such as, but not intended to be limited to, circular rolls, triangles, squares, ovals, arrowhead, bone, and other configurations, and of sizes different from the size described in this specification. Thus, the exemplary pad 100 has dimensions of approximately 3.5 cm x approximately 12 mm x approximately 8 mm (length by width by thickness).

Absorbent pad 100 comprises a core (or matrix) 102 which comprises an absorbent material and a bicomponent fiber. The absorbent material can be a mixture of absorbent materials, such as a cellulosic material and a superabsorbent material. The core 102 is disposed between first and second layers, 104, and 106, respectively, of a bicomponent fiber (Fig.2). Because the core 102 of this embodiment is cut to a generally rectangular form, core 102 includes two longitudinal sides 108, and ends 110. The absorbent pad 100 is formed such that the sides 108 and the ends 110 are exposed to the external environment. No additional member is needed to form an envelope to either surround the core 102, or to seal the core in order to retain the superabsorbent material within the core after the absorbent pad 100 has been manufactured or is being used.

The absorbent pad 100 is prepared using an airlaid process, known to those skilled in the art, which generally includes depositing a first layer 104 onto a moving surface, such as that of a conveyor belt, a screen or wire support, other moving support device, or the like, then depositing the mixture of absorbent materials and bicomponent fiber comprising the core 102. onto the first layer 104. This mixture includes a mixture of bicomponent fiber, absorbent material and superabsorbing material. After the core 102 mixture has been deposited, second layer 106 is deposited onto the core layer, followed by heating using a thermal binding process, also known to those skilled in the art. It is theorized that during this thermal binding process, one or more of the polymers within the bicomponent fiber layers becomes melted, and fuses with one or more of the molten polymers within the bicomponent fiber of the core. After the thermal bonding step has been completed, the material is cut into pads of an appropriate size, and packaged. In the finished product, the first layer 104 and second layer 106 have a thickness that is generally less than 1 mm, although this thickness can be varied depending upon the ultimate use of the product,

The first layer 104 and second layer 106 are formed from a bicomponent fiber. In this embodiment, the bicomponent fiber is a polyolefin fiber comprising a mixture of polyethylene and polypropylene, obtained from FiberVisions, Verda, Denmark, sold as AL-Delta Repeat. The bicomponent fibers comprise about 50% polyethylene and about 50% polypropylene, and up to about 1 % of a spin finish agent, comprising a mixture of nonionic emulsifiers and antistatic agents according to the manufacturer.

The core 102 of absorbent pad 100 is prepared from a mixture of absorbent materials and a bicomponent fiber. The absorbent materials comprise a cellulosic product, such as fluff pulp, and a superabsorbing material. The superabsorbing material can be in the form of either fibers, particles or granules, although the embodiment shown in the drawings utilizes superabsorbing fibers.

The fluff pulp is a cellulosic product that is commonly used in the manufacture of personal care items, such as feminine hygiene products, disposable diapers, and wound care products, and available from numerous suppliers. An exemplary type of such fluff pulp is obtained from a commercial supplier such as Weyerhaeuser Co. (Federal Way, WA). Fluff pulp is used in the preparation of the absorbent pad 100. Other types of absorbent materials can be included, or could be substituted for or be mixed with the fluff pulp. These materials include, for example, those made of absorbent hydrophilic materials such as cellulose fibers, including wood pulp, regenerated cellulose fibers or cotton fibers, or other absorbent materials generally known in the art, including acrylic fibers or polyvinyl alcohol fibers.

Superabsorbent materials can be obtained from a variety of commercial sources, and include a variety of both natural and synthetic compounds, and modified natural polymers and compounds. Silica gel is one example of an inorganic superabsorbing material. These materials include chemically modified starches, and hydrophilic polymers that have a great affinity for water such as polyvinyl alcohols, and polyolefins, such as a poly(ethylene oxide). Other examples of synthetic polymers that have superabsorbing properties include salts of poly(acrylic acid) and poly (methacrylic acid), poly(acrylamides), polyvinyl ethers), maleic anhydride copolymers with vinyl ethers and alpha-olefins, polyvinyl alcohol), polyvinyl pyrrolidones), and various mixtures and copolymers thereof.

Superabsorbent polymer fibers are hydrophilic fibers that are swellable, and are capable of absorbing greater than about 5 grams per gram (of fiber weight) of physiological saline solution (0.9% sodium chloride in water). Examples of superabsorbent polymer fibers are polyacrylate fibers, fibers of grafted cellulose, and fibers of maleic acid. Embodiments of the present invention utilize superabsorbent polymer fibers such OASIS® Type 101 , commercially available from Technical Absorbents Limited (Derbyshire, United Kingdom), or could utilize OASIS® Type 102, or LANSEAL® F, commercially available from Toyobo, Osaka, Japan. According to the manufacturer's literature, the OASIS® 101 superabsorbent is an acrylate copolymer for use in nonwoven textiles, yarns, and disposable hygiene products, and is a crosslinked copolymer comprising sodium acrylate, acrylic acid and methyl acrylate.

The absorbent pad could include a m ixture of different types of superabsorbent fibers and could additionally contain superabsorbent polymers in a form other than as fibers, such as in the form of particles or granules. The manufacturer's literature describes OASIS® superabsorbent material as an acrylate copolymer for use in nonwoven textiles, yarns, and disposable hygiene products. LANSEAL® F is described as a copolymer of poly acrylic acid and a poly ammonium acrylate, with a copolymer of poly(acrylonitrile).

Bicomponent fibers are manufactured using different types of and different blends of polyolefinic fibers, in order to impart particular characteristics and properties to the material. Thus, a manufacturer can modify properties such as softness, absorbancy, degree of hydrophilicity or hydrophobicity, cross-linking, and the like of the material, depending upon the particular blend of fibers employed.

In U.S. Pat. App. Pub. No. 2003/0114067 A1 Matela et al. discloses a variety of bicomponent fibers manufactured for use in absorbent articles such as diapers. These materials include, for example, a polymer component selected from the group consisting of polyethylene, polypropylene, fluropolyolefins, high pressure branched polyethylenes, linear low density polyethylenes, having an alpha- olefin comonomer content more than about 10% by weight, copolymers of ethylene with at least one vinyl monomer, copolymers of ethylene with unsaturated aliphatic carboxylic acids or derivatives thereof, copolymers of any two alpha-olefins having 2-20 carbon atoms wherein the content of each of the two comonomers exceeds 10% by weight of the copolymer, thermoplastic polyurethanes, and various block copolymers.

The bicomponent fiber in the core comprises a mixture of bicomponent fibers, both of which comprise a mixture of polypropylene and polyethylene. This bicomponent fiber mixture includes an approximately equal percentage of AL-Delta Repeat fiber, and another fiber, also obtained from FiberVisions, comprising about 35% by weight of polypropylene and about 60% by weight of polyethylene, and about 5% by weight of a chemically modified polyethylene using 1-butene as the comonomer.

The bicom ponent fibers com prise a m ixture of polypropylene and polyethylene fibers, and are described by their manufacturer as including up to about 1% of a spin finish agent, comprising a mixture of nonionic emulsifiers and antistatic agents. One type of bicomponent fiber comprises a mixture of about 35% polypropylene, 60% polyethylene, and 5% of a mixture of chemically modified polyethylenes which were synthesized using 1 -butene as a comonomer. Another type of bicomponent fiber comprises (by percent weight) a mixture of about 50% polypropylene and about 50% polyethylene, and about 1 % of a spin finish mixture (comprising nonionic emulsifiers and antistatic agents).

The absorbent article may have an approximately rectangular, oval, triangular, or other configuration. Forexample, "cotton rolls"typicallyhaveadiameterof about6-7mm, and alength of about 33-35 mm, although larger and smaller sizes are available. Sponges have generally square dimensions, such as, for example only and not intended to be limitations, of 2 x 2 inches, 3 x 3 inches, 4 x 4 inches, etc. Embodiments of the present invention can be produced in any of these sizes or configurations, or other sizes or configurations mandated by a specific function.

The superabsorbent material may be present in an amount that is less than about 70% by weight, based on the total weight of the materials in the core, and may be present in an amount that is less than 50% by weight, based on the total weight of the materials in the core; and may be used in an amount that is from about 25% to about 40% by weight, based on the total weight of the materials in the core. Embodiments in which the superabsorbent material was used in the core at concentrations of up to 70% by weight were functional.

Embodiments of the absorbent pad comprise the following, each agent expressed at a weight percent, based upon the total weight of the mixture, from about 20% to about 50% (based on the total weight) fluff pulp; from about 20% to about 50% (based on the total weight) polyolef in fiber; and from about 20% to about 70% (based on the total weight) superabsorbing fiber. In another embodiment, the absorbent pad comprises from about 25% to about 45% (based on the total weight) fluff pulp; from about 25% to about 45% (based on the total weight) polyolefin fiber; and from about 25% to about 45% (based on the total weight) superabsorbing fiber. In another embodiment, the absorbent pad comprises from about 30% to about 40% (based on the total weight) fluff pulp; from about 28% to about 38% (based on the total weight) polyolefin fiber; and from about 28% to about 38% (based on the total weight) superabsorbing fiber. Another embodiment could comprise from about 0% to about 50% (based on the total weight) fluff pulp; from about 28% to about 50% (based on the total weight) polyolefin fiber; and from about 28% to about 50% (based on the total weight) superabsorbing fiber.

The superabsorbent material used has an absorbent capacity of about 43-45 grams of 0.9% NaCI in water/gram of material, using the manufacturer's 15 minute freeswell capacity test. Using water, the absorbent capacity is greater than 135 grams per gram of material, according to the test described in Example 1.

The superabsorbent component can be either a fibrous or granular material. If a granular subperabsorbent is utilized, the pad must be contained within a bag or between a top and bottom membrane. Absorbent pads prepared using a fibrous superabsorbent do not require the presence of such a bag to keep the superabsorbent components within the pad once the pad has been used to absorb fluid.

An embodiment of the absorbent pad 100 is characterized by having a free swell of approximately 50 - 75 grams of fluid per gram of pad, and the pad is further characterized by having a free swell of approximately 55 - 65 grams of fluid per gram of pad. The absorbent pad 100 is characterized by having a water absorbancy of approximately 10 - 18 ml of water per pad, and is further characterized by having a water absorbancy of approximately 12 - 15 ml of fluid per gram of pad. This is in contrast to the absorbancy of cotton rolls, which are characterized by an absorbancy of approximately 5 ml of water per roll, and a free swell of approximately 8 grams of fluid per gram of roll. 1 Example 1. Comparison of Water Retention 2

3 To determine how much fluid the absorbent pads of the present invention could retain,

4 a free swell test was performed. Briefly, oven dried (100 degrees C oven, 4 hours) samples were initially

5 weighed, to three significant figures. To a beaker containing 900 ml of demineralized water, the tared pad

6 is suspended using a clamp, the tared pad is submerged in the water, and then removed after a specified

7 time, for example, one minute, has elapsed. The free swell test is generally performed at room

8 temperature (about 20 degrees C). The pad is then weighed again, and the difference is weight is the free

9 swell, which is expressed in terms of grams of water absorbed per gram of material tested. 10

11 The data in Table 1 represents the average results taken from four replicate samples,

12 determined to a ten-thousandth of a ml, but rounded off to the nearest hundredth ml. The free swell

13 determinations represent the average of four replicate experiments, determined to the hundredth of a

14 gram for the cotton rolls, or to the tenth of a gram for the absorbent pads of the present invention. 15

16 ===================================================

17 Table L AMOUNT OF WATER ABSORBED PER PAD 18

19 Sample Water Absorbed Free Swell

20 Per Pad (ml) (g/g)

21

22 Cotton Roll 5.19 7.95

23

24 Absorbent Pad 14.43 61.9

25 p c ==============—== ============—======—=== ==

27

28 Figure 3 shows the appearance of a pad that is wet, showing how it swells in one direction

29 after having absorbed fluid. As seen, the bulk of the swelling occurs in the core 102. 30

31 Thus, embodiments of the present invention can be used in a method to absorb fluids.

32 An absorbent pad or absorbent article is placed directly onto or in proximity to a fluid that needs to be

33 absorbed, the fluid is absorbed by the absorbent pad or absorbent article, and when the absorbent pad 34 or absorbent article has absorbed a sufficient amount of fluid, the absorbent pad or absorbent article is 35 removed. Depending upon the amount of fluid that needs to be absorbed, one or more absorbent pads 36 or absorbent articles may need to be used at different locations. If additional absorption is needed, 37 another absorbent pad or absorbent article is placed directly onto or in proximity of the fluid that needs 38 to be absorbed, and the process is repeated as needed.

39

40 Embodiments of absorbent pad 100 can be used in a method of retracting tissue that needs to be retracted, to enable access to a particular site. To do so, one or more of the absorbent pads are positioned against the area to be retracted. The pads are then contacted with a fluid to cause swelling of the pad. Examples of the fluids which can be utilized include water, saline (0.9% NaCI in water), plasma, glucose solution (generally approximately 5% dextrose in water or saline) or other fluids known to those skilled in the art. Additionally, such fluid could be a fluid from the individual whose tissue is being retracted, such as saliva or blood. Once the absorbent pad has swollen, the tissue is retracted. Depending upon space and the degree of retraction sought, either an additional pad could be positioned, or the procedure can employ, from the outset, another embodiment of absorbent pad 100 having a greater absorption capacity. In such a manner, the use of additional retracting clamps or other retracting devices could be reduced, minimized or eliminated, and the consequent risk of contamination with each additional item employed.

Additional uses for embodiments of the absorbent pad 100 can use in any of a variety of absorbent articles. Embodiments could thus be used as part of absorbent articles, such as, for example only, baby wipes, bandages, diapers, feminine hygiene products, incontinence pads, lap pads, nursing pads, pantiliners, sanitary napkin, surgical swabs, tampons, wound dressings, disposable wipers, and the like. Again, such uses can involve human, industrial and veterinary applications. Embodiments of the present described in this specification can be used without the need for a top or bottom layer of apertured material or nonapertured material. However, it may be optional to employ one or more layers of an apertured material or a nonapertured material in some of the uses described above for reasons of comfort, aesthetics or infection control, such as, for example only, to prevent the absorbed fluid from contacting a garment or to protect an area from being contaminated.

Additionally, and optionally, the absorbent article may comprise one or more other known materials, layers, and additives, depending upon the ultimate use of each embodiment. Accordingly, a backing or apertured layer may be added. Preservatives; antioxidants; medicaments, such as but not intended to be limited to, antimicrobial agents, antibacterial agents, antiviral agents, anti-fungal agents, anti-coagulant agents, astringents, coagulating agents, hemostatic agents, vasoconstricting agents, or other pharmaceutically active agents; could also be incorporated within the absorbent article. The absorbent article could also be imprinted or embossed with decorative designs or other indicia using conventional techniques.

Therefore, although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made only by way of illustration and that numerous changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.

Claims

CLAIMS.We claim:

1. An absorbent article comprising: a core including an absorbent material and a bicomponent fiber; a layer including a bicomponent fiber, the core being attached to the layer; the core not being completely surrounded by the layer, and the core and the layer being able to absorb a fluid.

2. The absorbent article as described in Claim 1 , wherein: the absorbent material comprises a cellulosic product and a superabsorbent material, and the superabsorbent material is in a form selected from the group consisting of fiber, particle, and granule.

3. The absorbent article as described in Claim 2, wherein the superabsorbent material is present in an amount less than about 70% by weight, based on the total weight of the materials in the core.

4. The absorbent article as described in Claim 3, wherein the superabsorbent material is present in an amount less than about 50% by weight, based on the total weight of the materials in the core.

5. The absorbent article as described in Claim 4, wherein the superabsorbent material is present in an amount from about 25% to about 40% by weight, based on the total weight of the materials in the core.

6. The absorbent article as described in Claim 1 , wherein the superabsorbent material is selected from the group consisting of an acrylate copolymer comprising sodium acrylate, acrylic acid and methyl acrylate, and a copolymer of poly acrylic acid and a poly ammonium acrylate, with a copolymer of poly(acrylonitrile).

7. The absorbent article as described in Claim 6, wherein the superabsorbent material is an acrylate copolymer comprising sodium acrylate, acrylic acid and methyl acrylate.

8. The absorbent article as described in Claim 2, wherein the cellulosic product comprises pulp.

9. The absorbent article as described in Claim 2, wherein the bicomponent fiber comprises polyethylene and polypropylene.

10. The absorbent article as described in Claim 1 , wherein in the core the bicom ponent fiber comprises about 35% (by weight) polypropylene and about 60% (by weight) polyethylene.

11. The absorbent article as described in Claim 7, wherein the article is characterized by having a free swell of approximately 50-75 grams of fluid per gram of absorbent article.

12. The absorbent article as described in Claim 11 , wherein the article is characterized by having a free swell of approximately 55-65 grams of fluid per gram of absorbent article.

13. The absorbent article as described in Claim 7, wherein the article is characterized by having a water absorbancy of approximately 10-18 grams of water per article.

14. The absorbent article as described in Claim 1 , wherein the absorbent article comprises one or more articles selected from the group consisting of saliva absorbers, disposable diapers, feminine hygiene products, wound dressings, surgical swabs, and disposable wipers.

15. An absorbent pad for absorbing a bodily fluid, the pad comprising: a core including an absorbent material and a bicomponent fiber; a layer including a bicomponent fiber, the core being attached to the layer; the core not being completely surrounded by the layer, and the core and the layer being able to absorb the bodily fluid.

16. The absorbent pad as described in Claim 15, wherein: the absorbent material comprises a cellulosic product and a superabsorbent material, and the superabsorbent material is in a form selected from the group consisting of fiber, particle, and granule.

17. The absorbent pad as described in Claim 16, wherein the superabsorbent material is present in an amount less than about 70% by weight, based on the total weight of the materials in the core.

18. The pad as described in Claim 17, wherein the superabsorbent material is present in an amount less than about 50% by weight, based on the total weight of the materials in the core.

19. The pad as described in Claim 18, wherein the superabsorbent material is present in an amount from about 25% to about 40% by weight, based on the total weight of the materials in the core.

20. The pad as described in Claim 16, wherein in the core, the superabsorbent material is selected from the group consisting of an acrylate copolymer comprising sodium acrylate, acrylic acid and methyl acrylate, and a copolymer of poly acrylic acid and a poly ammonium acrylate, with a copolymer of poly(acrylonitrile).

21. The pad as described in Claim 20, wherein in the core the superabsorbent material is an acrylate copolymer comprising sodium acrylate, acrylic acid and methyl acrylate.

22. The pad as described in Claim 16, wherein in the core the bicomponent fiber comprises about 35% (by weight) polypropylene and about 60% (by weight) polyethylene.

23. The absorbent article as described in Claim 16, wherein the article is characterized by having a water absorbancy of approximately 10-18 grams of water per article.

24. An article for retracting tissue, the article comprising: a core including an absorbent material, the core comprising a cellulosic product and a superabsorbent material, the superabsorbent material is in a form selected from the group consisting of fiber, particle, and granule; and a bicomponent fiber, and wherein the superabsorbent material is selected from the group consisting of an acrylate copolymer comprising sodium acrylate, acrylic acid and methyl acrylate, and a copolymer of poly acrylic acid and a poly ammonium acrylate, with a copolymer of poly(acrylonitrile); the superabsorbent material comprising less than about 70% by weight, based on the total weight of the materials in the core; a layer including a bicomponent fiber, the core being attached to the layer; the core not being completely surrounded by the layer, and the core and the layer being able to absorb a fluid, such that when the article is disposed near tissue and the article treated with the fluid, expansion of the treated article causes retraction of the tissue.

25. A method to retract tissue, the method comprising the steps of positioning an absorbent article in contact with, or in close proximity to, a surface in need of retraction, the absorbent article comprising: a core including an absorbent material, the core comprising a cellulosic product and a superabsorbent material, the superabsorbent material is in a form selected from the group consisting of fiber, particle, and granule; and a bicomponent fiber, and wherein the superabsorbent material is selected from the group consisting of an acrylate copolymer comprising sodium acrylate, acrylic acid and methyl acrylate, and a copolymer of poly acrylic acid and a poly ammonium acrylate, with a copolymer of poly(acrylonitrile); the superabsorbent material comprising less than about 70% by weight, based on the total weight of the materials in the core; a layer including a bicomponent fiber, the core being attached to the layer; the core not being completely surrounded by the layer, and the core and the layer being able to absorb a fluid, contacting the absorbent article with the fluid; allowing the fluid to be absorbed by the pad; expanding the absorbent article by the absorption of the fluid; and retracting the tissue as the absorbent article expands.

26. A method for absorbing a fluid, the method comprising the steps of: positioning an absorbent pad in contact with a surface having the fluid, the pad comprising: a core including an absorbent material and a bicomponent fiber; a layer including a bicomponent fiber, the core being attached to the layer; the core not being completely surrounded by the layer, and the core and the layer being able to absorb the fluid; contacting the absorbent article with the fluid; allowing the fluid to be absorbed by the pad.

27. The method as described in Claim 26, wherein: the absorbent material comprises a cellulosic product and a superabsorbent material, and the superabsorbent material is in a form selected from the group consisting of fiber, particle, and granule.

28. The method as described in Claim 27, wherein the superabsorbent material is present in an amount less than about 70% by weight, based on the total weight of the materials in the core.

29. The method as described in Claim 28, wherein the superabsorbent material is present in an amount less than about 50% by weight, based on the total weight of the materials in the core.