Taggant fibers

Abstract

Multicomponent fibers are provided that include a plurality of coextruded polymeric components arranged in discrete structured domains. The polymer domains have one or more identifying characteristics that can be varied to form a plurality of different identifying patterns. A plurality of islands in the sea fibers can be provided, the plurality of fibers including two or more subsets of fibers, each subset comprising a uniquely identifiable cross sectional pattern of island domains, each pattern being formed from an array comprising a predetermined number of island domains in predetermined locations within the array, wherein each pattern is determined by classifying individual island domains within the array as present or absent from the pattern. The plurality of fibers can be meltspun simultaneously to form a filament yarn or tow.

1 . A multicomponent fiber comprising two or more coextruded polymers arranged in discrete structured domains, wherein at least one of the polymer domains has at least one identifier characteristic that can be varied to form a plurality of different identifying patterns.  
   
   
       2 . The multicomponent fiber of  claim 1 , wherein said at least one identifier characteristic comprises the number of polymer domains present or absent in the fiber and the relative positions thereof in the fiber cross section, and wherein said fiber includes a sufficient number of polymer domains to provide a plurality of different identifying patterns formed by selecting different combinations of the domains be present or absent in the fiber.  
   
   
       3 . The multicomponent fiber of  claim 2 , wherein the number of polymer domains in the fiber is at least about 4 to provide at least about 12 different identifying patterns.  
   
   
       4 . The multicomponent fiber of  claim 1 , wherein said at least one identifier characteristic comprises at least one polymer domain having a distinctive cross section feature that can be varied to form a plurality of different identifying patterns.  
   
   
       5 . The multicomponent fiber of  claim 1 , further comprising at least one polymer domain that further has an additional unique physical characteristic that is different from that of other of the polymer domains to provide an additional identifying feature to the fiber.  
   
   
       6 . The multicomponent fiber of  claim 1 , wherein said fiber is an islands in the sea fiber having a plurality of island polymer domains within a surrounding sea polymer domain.  
   
   
       7 . A collection of multicomponent fibers according to  claim 1 , wherein each fiber is derived from a common multicomponent fiber construction comprising two or more coextruded polymers arranged in discrete structured domains, at least one of said domains having at least one identifier characteristic that can be varied to form a plurality of different identifying patterns, wherein the collection of fibers comprises a first subset of fibers exhibiting a first variation of said at least one identifier characteristic and a second subset of fibers exhibiting a second variation of said at least one identifier characteristic such that the first subset and the second subset are visually distinguishable from each other.  
   
   
       8 . The collection of multicomponent fibers of  claim 7 , wherein said at least one identifier characteristic comprises the number of polymer domains present or absent in the fibers, and wherein said different identifying patterns are formed by selecting different combinations of the domains be present or absent in the fiber.  
   
   
       9 . The collection of multicomponent fibers of  claim 7 , wherein said at least one identifier characteristic comprises at least one polymer domain having a distinctive cross section feature that can be varied to form different identifying patterns.  
   
   
       10 . The collection of multicomponent fibers of  claim 7 , wherein the collection of multicomponent fibers further comprises one or more additional subsets of fibers, each additional subset of fibers exhibiting a variation of said at least one identifier characteristic that is visually distinguishable from all other subsets.  
   
   
       11 . The collection of multicomponent fibers of  claim 7 , wherein the collection of fibers are derived from a common filament yarn or tow coextruded through the same spinneret.  
   
   
       12 . A collection of multicomponent fibers according to  claim 1 , wherein said multicomponent fibers are islands in the sea fibers, and wherein the collection of fibers comprises a first subset of fibers comprising a first uniquely identifiable cross sectional pattern of island domains and a second subset of fibers comprising a second uniquely identifiable cross sectional pattern of island domains, each pattern being formed from an array of a predetermined number of island domains in predetermined locations within the array, wherein each pattern is determined by classifying individual island domains within the array as present or absent from the pattern.  
   
   
       13 . The collection of multicomponent fibers of  claim 12 , wherein the collection of fibers are derived from a common filament yarn or tow coextruded through the same spinneret.  
   
   
       14 . The collection of multicomponent fibers of  claim 12 , wherein the collection of multicomponent fibers further comprises one or more additional subsets of fibers, each additional subset of fibers comprising a uniquely identifiable cross sectional pattern that is visually distinguishable from all other subsets.  
   
   
       15 . A collection of multicomponent fibers according to  claim 1 , wherein said multicomponent fibers are islands in the sea fibers, and wherein said collection of fibers comprises a first subset of fibers comprising a first uniquely identifiable cross sectional pattern of one or more island domains and at least one island domain comprising an array of protrusions on the periphery thereof and a second subset of fibers comprising a second uniquely identifiable cross sectional pattern of one or more island domains and at least one island domain comprising an array of protrusions on the periphery thereof, each pattern being determined by classifying individual protrusions on the at least one island domain as present or absent from the pattern.  
   
   
       16 . The collection of multicomponent fibers of  claim 15 , wherein the collection of fibers are derived from a common filament yarn or tow coextruded through the same spinneret.  
   
   
       17 . The collection of multicomponent fibers of  claim 15 , wherein the collection of multicomponent fibers further comprises one or more additional subsets of fibers, each additional subset of fibers comprising a uniquely identifiable cross sectional pattern that is visually distinguishable from all other subsets.  
   
   
       18 . The multicomponent fiber of  claim 1 , wherein at least one of the polymer domains comprises at least one void formed by solvent extraction of a soluble polymer.  
   
   
       19 . A taggant material for identifying a product, comprising a multicomponent fiber according to  claim 1 , or a portion thereof.  
   
   
       20 . A product comprising one or more multicomponent fibers according to  claim 1 , one or more portions thereof, or both, having a pattern formed by one or more of the shape, number, and arrangement of polymer domains in the fiber cross section suitable for use as a unique identifying pattern.  
   
   
       21 . A method of making an identifier material useful for tagging products, the method comprising: 
 defining a multicomponent fiber structure comprising a plurality of coextruded polymeric components arranged in discrete structured domains, wherein at least one of the polymer domains has at least one identifying characteristic that can be varied to form a plurality of different identifying patterns;    selecting at least one of said identifying patterns; and    melt extruding at least two different polymers under conditions selected to provide a multicomponent fiber having said selected identifying pattern.    
   
   
       22 . The method of  claim 21 , wherein said melt extruding step comprises melt extruding said polymers to form a plurality of multicomponent fibers comprising a first subset of fibers having a first selected identifying pattern and a second subset of fibers having a second selected identifying pattern, and wherein said method further comprises forming the multicomponent fibers into a yarn or tow.  
   
   
       23 . A method for melt-spinning a series of islands in the sea fibers using a unitary cross sectional fiber design based on an array of a predetermined number of island domains in predetermined locations within the array, comprising: 
 (a) providing a melt-spinning apparatus adapted for coextruding multiple flows of molten polymer through a spinneret;    (b) selecting a uniquely identifiable pattern of island domains by determining which island domains within the array will be present in the pattern and which island domains within the array will be absent;    (c) configuring the melt-spinning apparatus to provide the flows of molten polymer necessary to coextrude an islands in the sea fiber comprising the selected pattern of island domains;    (d) melt-spinning the islands in the sea fiber comprising the selected pattern of island domains; and    (e) optionally, repeating steps (b)-(d) for one or more additional uniquely identifiable patterns of island domains.    
   
   
       24 . The method of  claim 23 , wherein two or more subsets of fibers, each fiber subset comprising a uniquely identifiable pattern of island domains, are simultaneously meltspun to form a filament yarn or tow.