K-C Worldwide issued US patent for biodegradable and breathable film that can be used for such absorbent articles as diapers, training pants, disposable swimwear, incontinence garments and pads, sanitary napkins, wipes

Nevin Barich

ALEXANDRIA, Virginia , June 27, 2013 (Journal of Engineering) – From Alexandria, Virginia, VerticalNews journalists report that a patent by the inventors Wang, James H. (Appleton, WI); Shi, Bo (Neenah, WI), filed on December 22, 2009, was published online on June 18, 2013.

The patent's assignee for patent number 8466337 is Kimberly-Clark Worldwide, Inc. (Neenah, WI).

News editors obtained the following quote from the background information supplied by the inventors: "Polymer films are useful in making a variety of disposable articles because they are relatively inexpensive to manufacture, and can be made to be strong, durable, flexible, soft, and a barrier to aqueous liquids. Examples of such disposable products or articles include, but are not limited to, medical and health care products such as surgical drapes, gowns and bandages, protective work wear garments such as coveralls and lab coats, and infant, child and adult personal care absorbent articles such as diapers, training pants, disposable swimwear, incontinence garments and pads, sanitary napkins, wipes and the like. Other uses of polymeric film materials include geotextiles. It is often highly desirable for polymeric films used in such product applications to be both liquid impervious and breathable.

"It is known that breathable films can be prepared by blending an organic or inorganic incompatible filler with a polyolefin-based resin, which is then melted, film-formed and stretched. These films are mainly used as liquid barriers in disposable personal care products, which are discarded immediately after use. However, these breathable films prepared from the polyolefin-based resin are not made from renewable polymer resources and cannot be degraded in the natural environment.

"There is an increasing demand for the incorporation of more recyclable and/or degradable components in disposable products, and the design of products that can be disposed of by means other than by incorporation into solid waste disposal facilities such as landfills. As such, there is a need for new materials for disposable absorbent products that generally retain their integrity and strength during use, but after such use, are more efficiently disposable. For example, the disposable absorbent product may be easily and efficiently disposed of by composting. Alternatively, the disposable absorbent product may be easily and efficiently disposed of to a liquid sewage system wherein the disposable absorbent product is capable of being degraded.

"While it is possible to enhance the breathability and biodegradability of polymer films separately, enhancing the biodegradability of polymer films without diminishing the breathability of the films is difficult. For example, biodegradable films derived from copolyesters are known in the art. Although these films had high breathability, but they were made from petroleum-derived biodegradable polymers which do not contain any renewable polymer components such as renewable natural polymers.

"Accordingly, there remains a need for a composition which can be used to manufacture a biodegradable film which is also breathable and contains a renewable component, for use in making disposable or single-use articles of manufacture."

As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventors' summary information for this patent: "In one aspect of the invention is a biodegradable, breathable film made with a thermoplastic starch, in an amount ranging from about 20% to about 30% by weight of the film. Further included is an inorganic filler or organic filler or a mixture of both; and a biodegradable polymer resin, wherein the stretched film has a WVTR of about 2000 to about 2800 according to the MOCON test described herein.

"In another aspect of the invention is a method for manufacturing a biodegradable, breathable film having the steps of: a) forming a thermoplastic resin from starch, modified starch, or a mixture of starch and plant protein; b) melt blending the thermoplastic resin and a filler; and c) extruding the film from the melt blend and then stretching the film.

"In yet another aspect of the invention is a personal care article comprising:

"a sheet of biodegradable, breathable film comprising: a thermoplastic starch in an amount ranging from about 20% to about 30% by weight of the film; an inorganic filler or organic filler or a mixture of an inorganic and an organic filler; and a resin wherein the stretched film has a WVTR of about 2000 to about 2800 according to the MOCON test described herein."

For additional information on this patent, see: Wang, James H.; Shi, Bo. Biodegradable and Breathable Film. U.S. Patent Number 8466337, filed December 22, 2009, and published online on June 18, 2013. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=54&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=2697&f=G&l=50&co1=AND&d=PTXT&s1=20130618.PD.&OS=ISD/20130618&RS=ISD/20130618

Keywords for this news article include: Kimberly-Clark Worldwide Inc.

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