P&G issued US patent for method and apparatus for forming batt of particulate material for use as component in an absorbent core assembly

Nevin Barich

ALEXANDRIA, Virginia , January 9, 2014 (Journal of Engineering) – According to news reporting originating from Alexandria, Virginia, by VerticalNews journalists, a patent by the inventors Brown, Darrell Ian (Mason, OH); Walsh, Bradley Edward (Cincinnati, OH); Eckstein, Joseph Allen (Sunman, IN); Blessing, Horst (Cincinnati, OH); Maier, Volker (Euskirchen, DE); Link, Siegfried (Schleiden, DE), filed on July 9, 2012, was published online on December 31, 2013.

The assignee for this patent, patent number 8616867, is The Procter & Gamble Company (Cincinnati, OH).

Reporters obtained the following quote from the background information supplied by the inventors: "Disposable absorbent articles, such as diapers, are often constructed with an absorbent core assembly adapted to absorb bodily exudates and positioned between layers of materials. Such absorbent core assemblies may include a mixture of fibrous and particulate materials (e.g., fluff material and superabsorbent polymer), which are formed into a batt or wad. In turn, the batt or wad may be positioned between two or more layers of materials. One such layer may be a dusting layer adapted to face the wearer's body. Another such layer may be a core wrap adapted to face away from the person's body. The batt may not extend the entire length of the diaper, and thus, is generally intended to extend longitudinally inboard of the end edges of the diaper.

"In the manufacturing of the absorbent core assemblies, a variety of batt forming techniques may be utilized. For example, discrete batts may be formed with the use of vacuum zones within a laydown drum. In some configurations, superabsorbent polymer and fluff material are deposited onto a web partially wrapped around the outer surface of the laydown drum. Vacuum zones on the outer surface of the laydown drum help place and hold the superabsorbent polymer and fluff material in desired locations on the web. However, using some current techniques and apparatuses, some superabsorbent polymer and fluff material may be inadvertently deposited outside of the vacuum zones and outside desired locations on the web. For example, in some instances, superabsorbent polymer may be deposited substantially along the entire length of the diaper. As a result, the superabsorbent polymer may subsequently migrate through the topsheet, causing the superabsorbent polymer to be deposited on the wearer's skin. Such deposits may cause skin irritation; may be believed to cause skin irritation; and/or may be aesthetically unacceptable to a consumer. Additionally, fluff material inadvertently deposited substantially along the entire length of the diaper may interfere with an end seal necessary to contain the absorbent core assembly.

"In response to the aforementioned problems, some laydown drums may be configured with additional systems to help prevent the superabsorbent polymer and fluff mate from migrating outside the vacuum zones. For example, some laydown drums may include pneumatic systems that force compressed air through zones in the laydown drum to help prevent the deposit of particulate material along the entire length of the diaper. However, such systems add cost and complexity to the manufacturing process.

"Thus, there remains a need for simplified methods and apparatuses for forming batts comprising particulate material (e.g., fluff material and superabsorbent polymer) for use as a component in an absorbent core assembly."

In addition to obtaining background information on this patent, VerticalNews editors also obtained the inventors' summary information for this patent: "In some embodiments, the present disclosure is directed to an apparatus for forming a batt comprising particulate material, the apparatus comprising a support structure having an outer surface, a plurality of vacuum zones disposed on the outer surface of the support structure, at least one air impermeable fence zone adjacent to each vacuum zone, and at least one air permeable fence zone adjacent to each vacuum zone. The air permeable fence zone may comprise an ambient air entry conduit in fluid communication with an ambient air exit port. A vacuum applied beneath the vacuum zones may draw ambient air into the ambient air entry conduit and radially outward from the ambient air exit port. In some embodiments, the support structure may be a laydown drum.

"In some embodiments, the ambient air entry conduit does not extend through the surface of the laydown drum. A collective surface area of vacuum zones, air permeable fence zones, and air impermeable fence zones may equal a surface area of the outer surface of the laydown drum. The ambient air entry conduits may comprise fins at one or more laterally outermost edges of the ambient air entry conduits, whereby the fins direct ambient air into the ambient air entry conduit when the laydown drum is rotated. The vacuum zones may comprise a screen having a plurality of apertures.

"The air impermeable fence zones and the air permeable fence zones may have a greater height relative to the outer surface of the support structure than the vacuum zones. The air impermeable fence zones and the air permeable fence zones may be less than about 7 mm higher than the vacuum zones relative to the outer surface of the support structure.

"In some embodiments, the disclosure relates to a method of forming a batt comprising particulate material, the method comprising the steps of providing a support structure, the support structure having an outer surface and a plurality of vacuum zones, the vacuum zones being substantially permeable to permit vacuum air to pass through and into the laydown drum, a plurality of air impermeable fence zones, the air impermeable fence zones being substantially impermeable to inhibit air to pass through, the air impermeable fence zones being positioned laterally adjacent the vacuum zones on the outer surface of the support structure, and a plurality of air permeable fence zones, the air permeable fence zones comprising an ambient air entry conduit in communication with an ambient air exit port, the air permeable fence zones being substantially permeable to permit ambient air to pass through the air permeable fence zones, the air permeable fence zones being positioned between the vacuum zones on the surface of the support structure, generating a vacuum through the laydown drum such that air is drawn through the vacuum zones and the air permeable fence zones, and depositing a dispersion comprising air and particulate material such that the vacuum applied to the vacuum zones directs the dispersion to the vacuum zones whereupon the particulate material is positioned to form a batt.

"The method may further comprise providing a web of substrate material, pulling the web of substrate material substantially adjacent to the vacuum zones, and depositing the dispersion of air and particulate material on the web in the vacuum zones. In some embodiments, the method may include severing the first web to form a plurality of discrete batts. The method may further comprise the steps of providing a second web of material, positioning the second web of material adjacent the particulate material, and combining the second web of material to the first web of material. The combined webs may be severed to form a plurality of discrete batts.

"The first and second webs may be combined prior to severing the web to form the plurality of batts. The particulate material may comprise superabsorbent polymer particles. The superabsorbent polymer particles may be shielded after they are deposited. The first and second web of materials may be bonded."

For more information, see this patent: Brown, Darrell Ian; Walsh, Bradley Edward; Eckstein, Joseph Allen; Blessing, Horst; Maier, Volker; Link, Siegfried. Method and Apparatus for Forming a Batt of Particulate Material for Use as a Component in an Absorbent Core Assembly. U.S. Patent Number 8616867, filed July 9, 2012, and published online on December 31, 2013. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=103&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=5138&f=G&l=50&co1=AND&d=PTXT&s1=20131231.PD.&OS=ISD/20131231&RS=ISD/20131231

Keywords for this news article include: The Procter & Gamble Company.

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