Dispersible nonwoven webs and methods of manufacture
AssigneeThe Procter & Gamble Company
InventorJonathan Brennan
Life of this patent
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Abstract
Nonwoven webs that are comprised of non-thermoplastic fibers, have good in-use strength, and that disperse or break apart when subjected to agitation in water are disclosed. Pre-moistened wipes comprising such webs are also disclosed. The method of making the nonwoven webs is described as providing the webs with discrete compressed sites that form lines of weakness, such that the web may fail in tension along the lines of weakness when the web is subjected to a force less than the maximum force of the uncompressed regions of the web.
Claims20
A nonwoven web comprising:
- (a) non-thermoplastic fibers, wherein at least about 20% by weight of said non-thermoplastic fibers have a fiber length of at least about 18 mm;
- (b) a plurality of discrete compressed sites that are:
- i. less than about 2.5 square millimeters in area;
- and
- ii. separated by an edge to edge distance of no more than about 10 millimeters from the nearest adjacent discrete compressed site;
- (c) lines of weakness;
- and
- (d) discrete uncompressed regions, wherein said discrete uncompressed regions have an elongation at maximum force in the machine direction and an elongation at maximum force in the cross direction;
- wherein said (b) plurality of discrete compressed sites form said (c) lines of weakness and said (c) lines of weakness are arranged to substantially bound and define said (d) discrete uncompressed regions, such that when said web is subjected to a force less than the maximum force of said (d) discrete uncompressed regions in at least one of said machine direction or said cross direction, said web at least partially fails in tension along said (c) lines of weakness.
A process for increasing the dispersibility of a nonwoven web comprising non-thermoplastic fibers, wherein at least about 20% by weight of said non-thermoplastic fibers have a fiber length of at least about 18 mm, said process comprising the steps of:
- applying a compressive stress to said web of at least about 200 Newtons per square millimeter;
- and imparting said web with:
- (a) a plurality of discrete compressed sites that are:
- i. less than about 2.5 square millimeters in area;
- and
- ii. separated by an edge to edge distance of no more than about 10 millimeters from the nearest adjacent discrete compressed site;
- (b) lines of weakness;
- and
- (c) discrete uncompressed regions, wherein said discrete uncompressed regions have an elongation at maximum force in the machine direction and an elongation at maximum force in the cross direction;
- wherein said (a) plurality of discrete compressed sites form said (b) lines of weakness and said (b) lines of weakness are arranged to substantially bound and define said (c) discrete uncompressed regions, such that when said web is subjected to a force less than the maximum force of said (c) discrete uncompressed regions in at least one of said machine direction or said cross direction, said web at least partially fails in tension along said (b) lines of weakness.
A pre-moistened carded spunlaced nonwoven web comprising non-thermoplastic fibers selected from the group consisting of rayon fibers, pulp fibers and combinations thereof, wherein at least about 20% by weight of said fibers have a fiber length of at least about 38 millimeters, and further wherein said web comprises:
- (a) a plurality of discrete compressed sites that are:
- i. less than about 2.5 square millimeters in area;
- and
- ii. separated by an edge to edge distance of no more than about 10 millimeters from the nearest adjacent discrete compressed site;
- (b) lines of weakness;
- and
- (c) discrete uncompressed regions, wherein said discrete uncompressed regions have an elongation at maximum force in the machine direction and an elongation at maximum force in the cross direction;
- wherein said (a) plurality of discrete compressed sites form said (c) lines of weakness and said (b) lines of weakness are arranged to substantially bound and define said (c) discrete uncompressed regions, such that when said web is subjected to a cross direction force less than about 8 Newtons, said web at least partially fails in tension along said (b) lines of weakness.
Dependencies are inferred from the claim text.