Disposable absorbent articles

Disposable absorbent articles generally contain absorbent fibrous webs, such as airlaid or bonded carded webs. Such webs are often stabilized with binder fibers during web formation. 

Superabsorbent materials are frequently used in disposable absorbent articles to help improve the absorbent properties of such articles. Superabsorbent materials are generally polymer-based and are available in many forms, such as powders, granules, microparticles, films and fibers. Upon contact with fluids, superabsorbent materials swell by absorbing fluid into their structure. The superabsorbent materials quickly absorb fluids insulted into the articles and retain such fluids to prevent leakage and provide a dry feel even after fluid insult (3). 

Absorbency has both physical and chemical aspects. The unique character of water determines the properties of materials most able to accept, transport, and ultimately retain aqueous solutions. The absorbent process begins at the interface between the incoming fluid and the absorbent structure. With disposable absorbent articles, the coverstock has the responsibility of receiving and transmitting the fluid insult to the underlying absorbent core. The state-of-the-art core is air-laid cellulose fiber mixed with absorbent polymer. The capillary system of the fibrous batt has appreciable physical absorption capacity in addition to the ability to transport fluid to the absorbent polymer. Many water soluble polymers have been made into absorbent compositions, but the industry standard has become lightly crosslinked partially neutralized poly(acrylic acid). 

The first disposable absorbent article of commercial significance was the sanitary napkin introduced after the First World War. This product followed the development of the creping process whereby wet-laid paper (cellulose tissue) could be made soft yet strong. In the 1930s, Tampax Corporation introduced the internal catamenial absorption device, considered to be the ultimate in discreetness. The original Tampax brand tampon was oriented long staple cotton fiber overwrapped with a nonwoven rayon coversheet. The absorbent medium used In most modern tampons is wood fiber (cellulose fluff). Fluff is also the principal absorbent material used in disposable diapers and Incontinence devices. 

Schulte, T.E., VanRijswijck, L.G.S., and Roe, D.C., Absorbent Articles having Cuffs with Skin Care Composition Disposed Thereon, U.S. Patent 6,166,285, December 26, 2000. 

Personal hygiene is also important in minimizing exposure levels to harmful chemicals. Contaminated clothing should be immediately removed and laundered or disposed of. Absorbent articles of clothing such as belts and shoes are particularly troublesome. Provisions should be made for storage, laundering, and disposal of contaminated clothing. 

Several binder fibers have been developed that are biodegradable to enhance the disposability of the absorbent article. Most often, biodegradable polymers are formed from aliphatic polyester materials. A multicomponent fiber that contains a high melting aliphatic polyester and a low-melting aliphatic polyester has been developed (25). 

Lower-density E-plastomers have found alternate use in cast film processes to make elastic film laminates with good breathability which contain laminates of liquid impermeable extensible polymeric films with extensible-thermoplastic-polymer-fiber nonwovens and nonwoven webs of polyethylene-elastomer fibers as the intermediate layers. The development relates to a breathable film including an E-plastomer and filler that contributes to pore formation after fabrication and distension of the film. The method and extent of distension is designed to produce a breathable film by stretching the film to form micropores by separation of the film of the E-plastomer from the particulate solids. This film is useful for manufacture of absorbent personal-care articles, such as disposable diapers and sanitary napkins and medical garments. In detail, these constructions comprise a liquid impermeable extensible film comprising polyolefins. The outer layer contains extensible-thermoplastic-polymer-fiber nonwovens, and an elastic intermediate layer contains nonwoven webs of fiber E-plastomers. The intermediate layer is bonded to the film layer and the outer... 

The absorbent process in disposable articles, which begins with a fluid insult to the coversheet, continues at the interface between the coversheet and the absorbent core. Rapid transfer of fluid must occur to avoid runoff. The ability of the core to wick fluid away from the interface facilitates high flux. The absorption process is finished as the core reaches saturation. 

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