Articles and Methods Using Shape-Memory Polymers

Abstract

Articles comprise: a nonwoven fiber web and one or more strips bonded to the nonwoven fiber web. The strips comprise a shape-memory polymer that has a strained temporary shape and an intrinsic shape. If heated at or above a transition temperature, the strip at least partially converts from the strained temporary shape to the intrinsic shape, thereby causing at least one of folding, cupping, or puckering of the non-woven fiber web. Methods of heating the articles to provide folded, cupped, and/or puckered articles are also disclosed.

1 - 32 . (canceled) 
     
     
         33 . An article comprising:
 a nonwoven fiber web; and   a strip bonded to the nonwoven fiber web, wherein the strip comprises a shape-memory polymer, wherein the strip has a strained temporary shape and an intrinsic shape, and wherein if heated at or above a transition temperature, the strip at least partially converts from the strained temporary shape to the intrinsic shape, thereby causing at least one of folding, cupping, or puckering of the nonwoven fiber web, wherein the strip is bonded to the nonwoven fiber web at discrete points along the strip.   
     
     
         34 . An article comprising:
 a nonwoven fiber web; and   strips bonded to the nonwoven fiber web, wherein the strips comprise a shape-memory polymer, wherein each strip respectively has a strained temporary shape and an intrinsic shape, and wherein if heated at or above a transition temperature, the strips at least partially convert from their respective strained temporary shape to their respective intrinsic shape, thereby causing at least one of folding or puckering of the nonwoven fiber web, wherein at least a portion of the strips are interconnected.   
     
     
         35 . The article of  claim 34 , wherein the strips are linear. 
     
     
         36 . The article of  claim 34 , wherein the strips are disposed entirely on one major surface of the nonwoven fiber web. 
     
     
         37 . An article comprising:
 a nonwoven fiber web; and   
       strips bonded to the nonwoven fiber web, wherein the strips comprise a shape-memory polymer, wherein each strip respectively has a strained temporary shape and an intrinsic shape, and wherein if heated at or above a transition temperature, the strips at least partially convert from their respective strained temporary shape to their respective intrinsic shape, thereby causing at least one of folding or puckering of the nonwoven fiber web, wherein the strips are disposed on opposed major surfaces of the nonwoven fiber web. 
     
     
         38 . The article of  claim 37 , wherein at least some of the strips are disposed in a parallel arrangement. 
     
     
         39 . An article prepared according to a method of making an article, the method comprising: bonding a strip to a nonwoven fiber web, wherein the strip comprises a shape-memory polymer, wherein the strip has a strained temporary shape and an intrinsic shape, and wherein if heated at or above a transition temperature, the strip at least partially converts from the strained temporary shape to the respective intrinsic shape, thereby causing at least one of folding, cupping, or puckering of the nonwoven fiber web; and heating the strip at or above the transition temperature, wherein the article comprises a respirator mask. 
     
     
         40 . A method of making an article comprising bonding strips to a nonwoven fiber web, wherein the strips comprise a shape-memory polymer, wherein each strip respectively has a strained temporary shape and an intrinsic shape, and wherein if heated at or above a transition temperature, the strips at least partially convert from their respective strained temporary shape to their respective intrinsic shape, thereby causing at least one of folding, cupping, or puckering of the nonwoven fiber web, wherein the strips are disposed on opposed major surfaces of the nonwoven fiber web. 
     
     
         41 . The method of  claim 40 , further comprising heating the strips at or above the transition temperature. 
     
     
         42 . An article prepared according to the method of  claim 41 . 
     
     
         43 . The article of  claim 42 , wherein the article comprises a pleated filter. 
     
     
         44 . The method of  claim 40 , wherein the strips are linear. 
     
     
         45 . A method of making an article comprising bonding strips to a nonwoven fiber web, wherein the strips comprise a shape-memory polymer, wherein each strip respectively has a strained temporary shape and an intrinsic shape, and wherein if heated at or above a transition temperature, the strips at least partially convert from their respective strained temporary shape to their respective intrinsic shape, thereby causing at least one of folding, cupping, or puckering of the nonwoven fiber web, wherein at least some of the strips are disposed in a parallel arrangement. 
     
     
         46 . A method of making an article comprising bonding strips to a nonwoven fiber web, wherein the strips comprise a shape-memory polymer, wherein each strip respectively has a strained temporary shape and an intrinsic shape, and wherein if heated at or above a transition temperature, the strips at least partially convert from their respective strained temporary shape to their respective intrinsic shape, thereby causing at least one of folding, cupping, or puckering of the nonwoven fiber web, wherein at least some of the strips are interconnected. 
     
     
         47 . The method of  claim 46 , wherein the strips comprise a mesh