Splittable chargeable fiber, split multicomponent fiber, a split multicomponent fiber with a durable charge, nonwoven fabric, filter, and yarn containing, and manufacturing processes therefor

Abstract

A process for forming a splittable fiber having the steps of providing a multicomponent fiber; or a multicomponent staple fiber, providing a finish material, and at least partially coating the multicomponent fiber with the finish material to form a splittable fiber. The multicomponent fiber; or a multicomponent staple fiber, contains a first thermoplastic segment comprising polymer component A and a second thermoplastic segment comprising polymer component B. The finish material has an evaporation point of less than about 160° C. A process for forming a nonwoven fabric, a split multicomponent fiber, a split multicomponent fiber with a durable charge, a nonwoven fabric, and a filter and/or a spun yarn formed by the fibers herein is also described.

1 ) A process for forming a splittable fiber comprising the steps of:
 A) providing a multicomponent fiber; or a multicomponent staple fiber, comprising:
 i) a first thermoplastic segment comprising polymer component A; and 
 ii) a second thermoplastic segment comprising polymer component B; 
   B) providing a finish material, wherein the finish material has an evaporation point of less than about 160° C.; and   C) at least partially coating the multicomponent fiber; or a multicomponent staple fiber with the finish material to form a splittable fiber.   
     
     
         2 ) The process for forming a splittable fiber according to  claim 1 , further comprising the steps of removing the finish material from the splittable fiber after the fiber is split. 
     
     
         3 ) The process The method for forming a splittable fiber according to  claim 1 , wherein the finish material comprises a lubricant; or wherein the lubricant is selected from the group consisting of a plant-based oil, a natural oil, a synthetic oil, a water-soluble lubricant, and a combination thereof; or a vegetable oil, a mineral oil and a combination thereof; or a light vegetable oil, a light mineral oil, and a combination thereof; or a coconut oil, a corn oil, and a combination thereof. 
     
     
         4 ) The process for forming a splittable fiber according to  claim 1 , wherein when the splittable fiber is fully split into a plurality of sub-fibers, the sub fiber has a linear density of less than about 5 denier; or less than about 2 denier; or less than about 1 denier; or less than about 0.8 denier; or less than about 0.4 denier. 
     
     
         5 ) The process for forming a splittable fiber according to  claim 1 , wherein the coating step is selected from the group consisting of spraying the finish material onto the multicomponent fiber, immersing the multicomponent staple fiber in the finish material, contacting the fiber and a film of liquid finish material on the surface of a transfer roll, contacting the fiber with a bead of the finish material as the fiber passes through a grooved applicator, and a combination thereof; or a kiss-roll application process, a metered-finish application process, and a combination thereof. 
     
     
         6 ) (canceled) 
     
     
         7 ) A process for forming a split fiber comprising the steps of:
 A) providing a splittable fiber produced according to the process of  claim 1 ; and   B) splitting the splittable fiber in a carding process to form a split fiber.   
     
     
         8 ) The process for forming a split fiber according to  claim 7 , wherein the process does not employ a hydroentangling process. 
     
     
         9 ) The process for forming a split fiber according to  claim 7 , further comprising the step of electret charging the split fiber; or wherein the electret charging comprises a process selected from the group of corona charging, atmospheric plasma deposition, and a combination thereof; or wherein the electret charging comprises corona charging and atmospheric plasma deposition. 
     
     
         10 ) (canceled) 
     
     
         11 ) A process for forming a nonwoven fabric comprising the steps of:
 A) providing a splittable fiber by the steps of:
 i) providing a multicomponent fiber; or a multicomponent staple fiber, comprising:
 a) a first thermoplastic segment comprising polymer component A; and 
 b) a second thermoplastic segment comprising polymer component B; 
 
 ii) providing a finish material; or providing a finish material wherein the finish material has an evaporation point of less than 160° C.; and 
 iii) at least partially coating the multicomponent staple fiber with the finish material; and 
   B) forming the splittable fiber into a nonwoven fabric.   
     
     
         12 ) The process for forming a nonwoven fabric according to  claim 11 , further comprising the step of:
 providing a nonsplittable fiber,   
       wherein the forming step comprises forming the nonwoven web from the splittable fiber and the nonsplittable fiber. 
     
     
         13 ) The process for forming a nonwoven fabric according to  claim 11 , further comprising the step of removing, by weight, at least a portion of the finish material; or from about 50% to about 100% of the finish material; or from about 75% to about 100% of the finish material; or form about 80% to about 100% of the finish material. 
     
     
         14 ) (canceled) 
     
     
         15 ) The process for forming a nonwoven fabric according to  claim 11 , further comprising the step of:
 electret charging a thermoplastic component selected from the group consisting of the first thermoplastic component, the second thermoplastic component, and a combination thereof; or wherein the electret charging comprises a process selected from the group of corona charging, atmospheric plasma deposition, and a combination thereof; or wherein the electret charging comprises corona charging and atmospheric plasma deposition.   
     
     
         16 ) The process for forming a nonwoven fabric according to  claim 11 , wherein the forming step is selected from the group consisting of carding, thermal bonding, needle punching, spunbonding/spinbonding, air laying, hydroentanglement, melt blowing, hydro pulping, refining, wet laying, thorough air oven, cross-lapping, and a combination thereof; or thermal bonding, needle punching, hydropulping, wet-laying, chemical bonding, melt blowing, air laying, carding, needling, hydroentanglement, and a combination thereof; or thermal bonding, needle punching, hydropulping, wet laying, and combination thereof. 
     
     
         17 ) The process for forming a nonwoven fabric according to  claim 11 , further comprising the step of splitting the multicomponent staple fiber into a split fiber. 
     
     
         18 ) (canceled) 
     
     
         19 ) A nonwoven fabric produced according to the process of  claim 11 , further comprising an additional nonsplittable fiber; or an additional nonsplittable fiber having a linear density of from about 1 denier to about 20 denier. 
     
     
         20 ) (canceled) 
     
     
         21 ) (canceled) 
     
     
         22 ) (canceled) 
     
     
         23 ) The nonwoven fabric according to  claim 11 , further comprising a charge-enhancing additive. 
     
     
         24 ) A split multicomponent fiber comprising a durable charge. 
     
     
         25 ) The split multicomponent fiber according to  claim 24 , wherein the durable charge lasts for at least about 1 year; or at least about 2 years; or at least about 3 years. 
     
     
         26 ) (canceled) 
     
     
         27 ) The split multicomponent fiber according to  claim 24 , further comprising a charge-enhancing additive. 
     
     
         28 ) A nonwoven fabric comprising the split multicomponent fiber according to  claim 24 , further comprising a nonsplittable fiber. 
     
     
         29 ) (canceled) 
     
     
         30 ) (canceled) 
     
     
         31 ) (canceled)