Airlaid composite sheet material and method
Inventors
REN, Jichun • Wang, Juan • FENG, Xunwang • QU, Yijian • Newman, Marc
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-11891737-B2
Publication Date
2024-02-06
Expiration Date
Abstract
Provided is a composite sheet that is particularly useful as an AQDL component in absorbent articles. The composite sheet includes a fluid acquisition component and an airlaid component. The airlaid component may include one or more airlaid layers that are successively formed overlying each other. Each of the airlaid layers are adjacent to, and in direct contact with, immediately adjacent layers of the airlaid component so that adjacent layers are in fluid communication with respect to each other. The fluid acquisition component includes a nonwoven fabric comprising a carded nonwoven fabric comprised of a plurality of staple fibers that are air through bonded to each other to form a coherent nonwoven fabric. The airlaid layer(s) include a blend of cellulose and non-cellulose staple fibers. The staple fibers may be bicomponent fibers having a polyethyelene sheath and a polypropylene or polyethylene terephthalate core, and mixtures of such fibers.
Core Innovation
The invention describes a composite sheet for an absorbent-article AQDL composite sheet in which a fluid acquisition component is formed from an air-through-bonded carded nonwoven fabric and an overlying airlaid component. The carded nonwoven fabric comprises staple fibers, and the airlaid component comprises airlaid layers made from a cellulose staple-fiber and a non-cellulose staple-fiber blend. The airlaid layers are deposited directly adjacent in fluid communication to form an airlaid component over the carded nonwoven fabric.
The composite sheet is air through bonded with heated gas to cause polymer of the non-cellulose staple fibers in the airlaid layer to melt and fuse with adjacent staple fibers. As a result, adjacent fibers of the cellulose staple fibers and adjacent fibers of the non-cellulose staple fibers are bonded to each other and to staple fibers of the carded nonwoven fabric, producing a coherent composite sheet. The bonding fuses the fibers without extra adhesives/powder resins by melting and fusing the low-melt polymer of bicomponent fibers.
The composite sheet is characterized by selected fluid transport and comfort performance ranges, including a basis weight from about 40 to 225 g/m2, a fluid acquisition time from about 0.5 seconds to about 2 seconds, fluid absorption from about 15 to 30 g/g, fluid retention from about 8 to 15 g/g, fluid wicking height from about 10 to 50 mm, and resiliency from about 30 to 60%. The document further describes optional latex coating on the outermost airlaid layer and embossing with alternating ridges and channels to improve lateral distribution.
Claims Coverage
The partial content includes two independent claims, each directed to preparing a coherent composite sheet with specified fluid acquisition and fluid transport/resiliency characteristics. Across the independent claims, the coverage focuses on depositing cellulose/non-cellulose staple-fiber airlaid layers adjacent to a carded nonwoven layer and bonding to form a coherent composite using air-through heated-gas polymer melting and fiber fusing. The main performance ranges define the claimed sheet characteristics.
Air-through heated-gas bonding to melt and fuse polymer-containing non-cellulose staple fibers
Air through bonding a composite sheet with heated gas to cause the polymer of the non-cellulose staple fibers of the first airlaid layer to melt and fuse with adjacent staple fibers of the fabric, and wherein adjacent fibers of the cellulose staple fibers and adjacent fibers of the non-cellulose staple fibers are bonded to each other and to the staple fibers of the carded nonwoven fabric.
Depositing a mixture cellulose/non-cellulose staple fibers airlaid layer adjacent to a carded nonwoven fabric
Depositing a first airlaid layer onto a surface of the carded nonwoven fabric to form a composite sheet, the first airlaid layer comprising a mixture of cellulose staple fibers and non-cellulose staple fibers comprising a polymer.
Specified fluid acquisition and transport/resiliency performance ranges for the composite sheet
Characterizing the composite sheet by a fluid acquisition time ranging from about 0.5 seconds to about 2 seconds, a fluid absorption ranging from about 15 to 30 g/g, a fluid retention ranging from about 8 to 15 g/g, a fluid wicking height ranging from about 10 to 50 mm, and a resiliency ranging from about 30 to 60%.
Bonding staple fibers of a nonwoven fabric layer to airlaid cellulose/non-cellulose staple fibers to form a coherent composite
Depositing a plurality of non-cellulose staple fibers onto a collection surface to form a first nonwoven fabric layer, depositing a first airlaid layer onto a surface of the first nonwoven fabric layer (the first airlaid layer comprising a mixture of cellulose staple fibers and non-cellulose staple fibers), and bonding the staple fibers of the first nonwoven fabric layer to the cellulose staple fibers and the non-cellulose staple fibers of the first airlaid layer to form a coherent composite sheet.
The independent claims are grounded in forming a coherent composite sheet by combining a carded/nonwoven staple-fiber layer with an airlaid layer that contains a mixture of cellulose staple fibers and polymer-containing non-cellulose staple fibers, and then bonding the fibers to each other using heated-gas air-through polymer melting and fusing. The resulting sheet is defined by specific ranges for fluid acquisition time, fluid absorption, fluid retention, fluid wicking height, and resiliency.
Stated Advantages
Improved fluid acquisition and transport performance characterized by specified fluid acquisition time, absorption, retention, and wicking height ranges.
Improved resiliency characterized by a resiliency range of about 30 to 60%.
Documented Applications
Example placements in diapers.
Example placements in feminine sanitary pads.
Interested in licensing this patent?