Flame-retardant non-woven fibrous webs
Assignee3M Innovative Properties Company
InventorsTien T. Wu, Pingfan Wu, Liyun Ren
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Abstract
A nonwoven fibrous web and a method of making thereof. The nonwoven fibrous web includes greater than 0% but no greater than 30 wt % of a plurality of melt-blown fibers comprised of a crystalline (co)polymer; and at least 70 wt % of a plurality of randomly-oriented staple fibers, the plurality of randomly-oriented staple fibers including: at least 60 wt % of oxidized polyacrylonitrile fibers; and from 0 to 40 wt % of reinforcing fibers having an outer surface comprised of a (co)polymer with a melting temperature of from 100° C. to 350° C.; wherein the plurality of melt-blown fibers and the plurality of randomly-oriented staple fibers are bonded together to form a cohesive non-woven fibrous web.
Claims15
A nonwoven fibrous web comprising
- greater than 0% but no greater than 30 wt % of a plurality of melt-blown fibers comprised of a crystalline (co)polymer;
- and
- at least 70 wt % of a plurality of randomly-oriented staple fibers, the plurality of randomly-oriented staple fibers comprising:
- at least 60 wt % of oxidized polyacrylonitrile fibers;
- and
- from 0 to 40 wt % of reinforcing fibers having an outer surface comprised of a (co)polymer with a melting temperature of from 100° C. to 350° C.;
- wherein the plurality of melt-blown fibers and the plurality of randomly-oriented staple fibers are bonded together to form a cohesive non-woven fibrous web, optionally wherein the crystalline (co)polymer exhibits a melting temperature from 100° C. to 250° C.
A non-woven fibrous web comprising
- a cohesive nonwoven fibrous matrix comprising of a plurality of randomly-oriented staple fibers, the plurality of randomly-oriented staple fibers comprising:
- at least 60 wt % of oxidized polyacrylonitrile fibers;
- and
- from 0 to 40 wt % of reinforcing fibers having an outer surface comprised of a (co) polymer with a melting temperature of from 100° C. to 350° C.;
- wherein the plurality of randomly-oriented staple fibers are bonded together to form the cohesive non-woven fibrous matrix;
- and
- a plurality of discrete domains of at least partially melted melt-blown fibers distributed within the cohesive nonwoven fibrous matrix, wherein the at least partially melted melt-blown fibers comprise a crystalline (co)polymer, optionally wherein the crystalline (co)polymer exhibits a melting temperature from 100° C. to 250° C.
A method of making a cohesive nonwoven fibrous web comprising:
- mixing a plurality of oxidized polyacrylonitrile fibers with a plurality of reinforcing fibers to form a mixture of randomly-oriented fibers, wherein the plurality of reinforcing fibers have outer fiber surfaces comprised of a (co)polymer with a melting temperature between 100° C. and 350° C.;
- combining the mixture of randomly-oriented fibers with a plurality of melt-blown fibers comprised of a crystalline (co)polymer to form nonwoven fibrous web;
- and
- heating the mixture of randomly-oriented fibers combined with the plurality of melt-blown fibers to a temperature sufficient to melt the outer surfaces of the plurality of reinforcing fibers;
- optionally wherein the crystalline (co)polymer exhibits a melting temperature from 100° C. to 250° C.
Dependencies are inferred from the claim text.