Insulation with reactive flaps

Abstract

Insulation comprises a plurality of reactive flaps that react to one or more external stimuli, e.g., humidity. The flaps are made up of a fiber mixture that includes: 20-80 wt % reactive bicomponent fibers that are reactive to an external stimulus, and have a first configuration in an unactivated state and a second configuration in an activated state, and wherein the bicomponent fibers can reversibly transform between the unactivated and activated states; 5-40 wt % synthetic binder fibers having a denier of 1.5 to 4.0 denier; 0-75 wt % of a first population of synthetic fibers, being synthetic polymeric fibers having a denier of less than 2.0 denier; and 0-75 wt % of a second population of synthetic fibers, being synthetic polymeric fibers having a denier of 4.0 to 10.0 denier. Related articles and methods are also provided.

1 . Insulation having a plurality of reactive flaps therein, such that the insulation comprises the flaps and also non-flap portions, wherein said reactive flaps comprise a flap fiber mixture that comprises:
 20-80 wt % bicomponent fibers having a core and a sheath, said fibers having a denier of 2.0 to 8.0 denier, and a staple cut length of 38 to 105 mm, wherein said bicomponent fibers are reactive to an external stimulus, and have a first configuration in an unactivated state and a second configuration in an activated state, and wherein the bicomponent fibers can reversibly transform between the unactivated and activated states;   5-40 wt % synthetic binder fibers having a denier of 1.5 to 4.0 denier and a staple cut length of 38 to 105 mm;   0-75 wt % of a first population of synthetic fibers, being synthetic polymeric fibers having a denier of less than 2.0 denier and a staple cut length of 38 to 105 mm; and   0-75 wt % of a second population of synthetic fibers, being synthetic polymeric fibers having a denier of 4.0 to 10.0 denier and a staple cut length of 38 to 105 mm.   
     
     
         2 . The insulation according to  claim 1 , wherein said insulation is non-woven. 
     
     
         3 . The insulation according to  claim 1 , wherein the fibers of the first population of synthetic fibers are siliconized. 
     
     
         4 . The insulation according to  claim 1 , wherein the fibers of the second population of synthetic fibers are siliconized. 
     
     
         5 . The insulation according to  claim 1 , wherein the fibers of the first population of synthetic fibers have a standard crimp. 
     
     
         6 . The insulation according to  claim 1 , wherein the fibers of the second population of synthetic fibers have a spring-like crimp. 
     
     
         7 . The insulation according to  claim 6 , wherein the fibers of the second population of synthetic fibers have a helical crimp. 
     
     
         8 . The insulation according to  claim 1 , wherein the non-flap portions of the insulation comprise a non-flap fiber mixture that is the same as the flap fiber mixture. 
     
     
         9 . The insulation according to  claim 1 , wherein the bicomponent fibers comprise 20 to 50 wt % core material and 50 to 80 wt % sheath material. 
     
     
         10 . The insulation according to  claim 1 , wherein the core of the bicomponent fibers comprises a non-hygroscopic core material and the sheath of the bicomponent fibers comprises a hygroscopic sheath material. 
     
     
         11 . The insulation according to  claim 1 , wherein the core of the bicomponent fibers comprises polypropylene and the sheath comprises nylon. 
     
     
         12 . The insulation according to  claim 1 , wherein the bicomponent fibers comprise 20 to 40 wt % core material and 60 to 80 wt % sheath material. 
     
     
         13 . The insulation according to  claim 1 , wherein the core of the bicomponent fibers is an off-center core. 
     
     
         14 . The insulation according to  claim 1 , wherein the second configuration has increased twist as compared to the first configuration. 
     
     
         15 . The insulation according to  claim 1 , wherein the bicomponent fibers have a helical crimp. 
     
     
         16 . The insulation according to  claim 15 , wherein the first configuration is a helix and the second configuration is a helix with relatively decreased radius and pitch as compared to the first configuration. 
     
     
         17 . The insulation according to  claim 1 , wherein the flap fiber mixture comprises:
 40-80 wt % of the bicomponent fibers;   10-40 wt % of the synthetic binder fibers; and   5-50 wt % of the first population of synthetic fibers, wherein said first population of synthetic fibers are siliconized and have a denier of less than 1.5 denier.   
     
     
         18 . An article comprising the insulation according to  claim 1 . 
     
     
         19 . The article according to  claim 18 , wherein said article is selected from footwear, outerwear, clothing, sleeping bags, and bedding. 
     
     
         20 . A method of making the insulation according to  claim 1 , said method comprising:
 forming an intermediate insulation from a fiber mixture, said intermediate insulation comprising a plurality of flap areas that comprise the flap fiber mixture;   heating the intermediate insulation in excess of the bonding temperature of the binder fibers in the flap fiber mixture; and   forming a plurality of flaps in the intermediate insulation, thereby creating a plurality of reactive flaps.   
     
     
         21 . The method according to  claim 20 , wherein said forming a plurality of flaps in the intermediate insulation comprises laser-cutting flaps in the intermediate insulation.