1999 - Volume 2 - Journal of Engineered Fibers and Fabrics

Patent Review
a melting point in the range of about 50 to 70 0 C. Although this waxy lipid material is solid at ambient
temperatures, it also needs to be fluid or plastic at those temperatures at which the high internal phase
inverse emulsion is applied to the substrate. The major component of the high internal phase inverse
emulsion is the dispersed internal polar phase which consists of water, comprising about 85 to 94% by
weight.
The inventors point out that a wide variety of materials can be combined with the ingredients of the
inverse emulsion, such as emollients, medicaments, bleach, surfactant, solvents, disinfectants, chelating
agents and others.
Suitable substrates to be with this wipe can be of various types. Nonwoven fabrics, particularly those
with regions of low and high density are particularly useful. Also, the nonwoven fabric can be apertured
to provide an extreme case of density differentiation. Airlaid pulp webs and wetform webs can be
employed, along with various types of tissue products.
A variety of patterns for application of the inverse phase emulsions are suggested by the inventors. The
emulsion can be employed in stripes, which affords coated regions adjacent to non-coated regions in the
final wiping product. Also, a variety of other patterns can be employed, including patterns which involve
topic designs suitable for aesthetic enhancement.
U.S. 5,914,177 (June 22, 1999); filed August 11, 1997. "Wipes having a substrate with a discontinuous
pattern of a high internal phase inverse emulsion disposed thereon and process of making." Assignee:
The Procter & Gamble Company. Inventors: Charles Zell Smith, III, Steven Lee Barnholtz, David
William Cabell.
Superfine Microfiber Nonwoven Web
Microfiber webs, such as meltblown fiber webs are well known and have found application in a wide
variety of industrial, consumer and medical products. Despite the use and utility of these webs, there is a
continuing quest for fiber webs containing even finer microfiber. For many applications, the finer the
fiber, the greater the performance enhancement.
There have been various attempts to reduce the diameter of meltblown fibers by a variety of methods.
One such approach is to reduce the polymer through-put to the die head. However, this direct approach
can only be used to reduce the fiber size to a limited extent, since increasing reduction in the resin
through-put eventually interrupts the fiber production altogether.
Another method that has been attempted to produce superfine meltblown webs involves producing
bicomponent conjugate meltblown fibers of the island-in-sea configuration and then dissolving the sea
component. This does produce microfibers, but the dissolving process is a distinct disadvantage;
consequently, this method is uneconomical and inefficient, and so it is seldom used.
Hydro-needling has been attempted to produce superfine microfibers. This involves the use of
pressurized jets of water to split multi-component conjugate fibers. While this method is applicable to
some nonwoven processes, it has not been used to produce split meltblown fiber webs, since the
autogenously bonded meltblown fiber webs are quite weak and contain a numerous interfiber bonds that
restrict fiber movements; consequently, these webs are very difficult to split with a mechanical splitting
process without substantially destroying the web.
The present invention provides a web containing superfine microfibers. This web is produced from
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