Novel ignition resistant cotton fiber, articles made from ignition resistant cotton fibers, and methods of manufacture

Abstract

A bi-regional fiber with a cellulosic core and a wax outer sheath is disclosed. The sheath can comprise high melting temperature wax. The fiber may be produced by processing the natural fiber at temperatures less than 70° C. The fiber can be processed in a standard manner, e.g., Keir process which may include bleach at approximately 100° C.. and the wax subsequently added at a temperature sufficient to disperse the wax over the fibers. The fibers are ignition resistant as measured by industry standard tests, e.g., FAR 25.853(b) or 14 CFR 25.853(b). The wax may comprise less than 1 percent to 25 percent of the fiber by weight. The wax may be natural wax, synthetic or emulsified wax or blends thereof. The bi-regional fibers can be blended with other fibers including BRCF fibers subject of U.S. Pat. No. 5,700,573.

What is claimed is: 
     
         1 . An ignition resistant fiber or assembly of fibers comprising a fiber having a cellulosic center and an outer region or surface of a wax wherein the wax comprises 0.4 to 1.0 or greater percentage by weight of fiber. 
     
     
         2 . The fiber or assembly of fibers of  claim 1  further comprising an outer region of a high temperature melting wax. 
     
     
         3 . The fiber or assembly of fiber of  claim 2  further comprising an outer region of wax having a melting point of 70° C. or higher. 
     
     
         4 . The fiber or assembly of fibers of  claim 1  further comprising a cellulosic center of cotton fiber. 
     
     
         5 . The fiber or assembly of fibers of  claim 1 , wherein said wax is a natural wax. 
     
     
         6 . The fiber of  claim 1  or assembly of fibers, wherein the said wax is a emulsified wax or mixtures of emulsified waxes. 
     
     
         7 . The fiber or assembly of fibers of  claim 1 , wherein said wax is a mixture of natural and emulsified waxes. 
     
     
         8 . The fiber or assembly of fibers of  claim 1 , wherein said wax is cotton wax. 
     
     
         9 . The fiber or assembly of fibers of  claim 1  wherein said wax is jojoba wax. 
     
     
         10 . The fiber or assembly of fibers of  claim 1  wherein said wax is high melting soy wax. 
     
     
         11 . The fiber or assembly of fibers of  claim 1  wherein said wax is carnuba wax 
     
     
         12 . The fiber or assembly of fibers of  claim 2  wherein the wax is selected form a group consisting of natural wax, emulsified wax, a mixture of emulsified waxes, a mixture of emulsified waxes and natural wax, cotton wax, jojoba wax, high melting soy wax, carnuba wax or combinations thereof. 
     
     
         13 . The fiber or assembly of fibers comprising bi-regional cotton of  claim 1  is 10% to 20% stronger than standard high temperature high alkalinity processed cotton. 
     
     
         14 . The fiber or assembly of fibers of  claim 1  wherein the fibers have reduced absorption of water than high temperature high alkalinity processed cotton. 
     
     
         15 . The fiber or assembly of fibers of  claim 1  wherein the fibers have improved wrinkle resistance to high temperature high alkalinity process cotton. 
     
     
         16 . The fiber or assembly of fibers of  claim 1  further comprising applying a saponified acid derivative selected from a group consisting of Lauric, Myristic, Palmitic, Stearic, Oleic or combinations thereof. 
     
     
         17 . Bi-regional cotton fibers comprising a cellulosic center and an outer region of high temperature wax wherein the fibers pass a standard vertical burn tests conducted according to FAR 25.853(b). 
     
     
         18 . Bi-regional cotton fibers comprising a cellulosic center and an outer region of a cotton wax, a natural wax, or a blend of natural and synthetic waxes melting in the range of 58 to 87° C. wherein the fiber passes an ignition resistance test comprising: a minimum of three battings having a dimension of 2.5 cm×15 cm×30 cm and comprised of 80% the bi-regional carbonaceous fibers and 20% polyester fibers sprayed with a solution of a hydrolyzed partial condensation of trimethoxy methyl silane wherein the battings are compressed at 25 lb/in 2  (1.75 Kg/cm 2 ) at a temperature of 260° F. (127° C.) into panels and wherein the coating is comprised of 10% by weight, wherein standard vertical burn tests according to FAR 25.853(b) are conducted, wherein the panels are conditioned by maintaining the panels in a conditioning room maintained at a temperature of 21° C.±5° C. and 50%±5% relative humidity for 24 hours preceding the test, wherein each panel is supported vertically and exposed to a Bunsen or Turill burner with a nominal I.D. tube adjusted to give a flame of 3.8 cm in height with a minimum flame temperature is 843° C., wherein the lower edge of the panel is 1.9 cm above the top edge of the burner, wherein the flame is applied to the center line of the lower edge of the specimens for 12 seconds and then removed and wherein the panel self extinguishes and average burn length does not exceed 20 cm, the average after flame does not exceed 15 seconds and there are no flame drippings. 
     
     
         19 . Bi-regional cotton fibers comprising a cellulosic center and an outer region of a cotton wax, a natural wax, or blend of natural and synthetic waxes melting in the range of below 58° C. wherein the fiber passes an ignition resistance test comprising: a minimum of three battings having a dimension of 2.5 cm×15 cm×30 cm and comprised of 80% the bi-regional carbonaceous fibers and 20% polyester fibers sprayed with a solution of a hydrolyzed partial condensation of trimethoxy methyl silane wherein the battings are compressed at 25 lb/in 2  (1.75 Kg/cm 2 ) at a temperature of 260° F. (127° C.) into panels and wherein the coating is comprised of 10% by weight, wherein standard vertical burn tests according to FAR 25.853(b) are conducted, wherein the panels are conditioned by maintaining the panels in a conditioning room maintained at a temperature of 21° C. ±5° C. and 50%±5% relative humidity for 24 hours preceding the test, wherein each panel is supported vertically and exposed to a Bunsen or Turill burner with a nominal I.D. tube adjusted to give a flame of 3.8 cm in height with a minimum flame temperature is 843° C., wherein the lower edge of the panel is 1.9 cm above the top edge of the burner, wherein the flame is applied to the center line of the lower edge of the specimens for 12 seconds and then removed and wherein the panel self extinguishes and average burn length does not exceed 20 cm, the average after flame does not exceed 15 seconds and there are no flame drippings. 
     
     
         20 . A fabric or fiber assembly comprising bi-regional cotton fibers comprising a cellulosic center and an outer region of a wax wherein the fibers passes Testing Flammability of Clothing Textiles, 16 CFR 1610, comprising fabric specimens of 2 inches by 6 inches are dried and cooled, the specimens are placed at a 45° angle impinged with a flame of ⅝ inch length for a second wherein a plain surface fabric burn time is 3.5 seconds or more and a raised surface fabric average burn time is 7 seconds or more. 
     
     
         21 . An ignition resistant fiber or assembly of fibers comprising a fiber having a cellulosic center and an outer region of a wax wherein the wax comprises 0.4 to 25 percent of the fibers by weight. 
     
     
         22 . The fibers or assembly of fiber of  claim 16  wherein the wax comprises 1.0 to 15 percent of the fibers by weight. 
     
     
         23 . The fibers or assembly of fibers of  claim 16  wherein the wax comprises 10 to 25 percent of the fibers by weight. 
     
     
         24 . The fibers or assembly of fibers of  claim 16  wherein the wax comprises 14 to 16 percent of the fibers by weight. 
     
     
         25 . Bi-regional cotton fiber comprising a cellulosic center and an outer region comprising a wax coating wherein the wax comprises 0.4 percent to 1.5 percent by weight of the fiber. 
     
     
         26 . A bi-regional fiber having a cellulosic center and an outer wax coating bleached in a low temperature—peroxide/catalyst or low alkalinity hypochlorite process employing an oxidative process to remove impurities. 
     
     
         27 . A process of making an ignition resistant cotton fiber where said fiber is derived from an ECRU or raw cotton fiber by bleaching fiber at less than 70° C. with a bleaching solution comprising a peroxide, peroxide catalyst, and a wetting agent. 
     
     
         28 . A process of bleaching cotton fiber comprising a bleach solution of 1 g/l Cl 2  at a temperature not exceeding 40° C. 
     
     
         29 . A treatment process for raw cotton comprising treating the raw cotton at a temperature below 75° C. and a peroxide/catalyst or low alkalinity hypochlorite process. 
     
     
         30 . A process of treating raw cotton of  claim 22  further comprising omitting a post treatment acid wash step. 
     
     
         31 . A process of making an ignition resistant cotton fiber where said fiber is derived from an ECRU or raw cotton fiber by bleaching fiber at less than 70° C. with a bleaching solution comprising an OX −  system, where X is a halogen and where the pH is 6.5 to 8. 
     
     
         32 . A process of making an ignition resistant cotton fiber where said fiber is derived from a standard bleaching process where an outer region comprises a natural, emulsified or blend of wax that is added subsequent to the bleaching process. 
     
     
         33 . The process of  claim 25  further comprising wax comprising a high temperature melting wax. 
     
     
         34 . A blended fire retardant fiber assembly comprising from 10 to 90% of bi-regional cotton fibers with BRCF fibers wherein the blended fibers comprises fire retardant properties.