Process for improving the chemical and/or physical properties of hollow-structure natural fibers

Abstract

For improving the chemical and/or the physical properties of hollow-structure natural fibers, such as kapok fibers, the fibers are subjected to a process, which determines the internal coating and/or filling thereof, at least partly, with a substance capable of improving the chemical and/or the physical properties of the fibers.

1 - 21 . (canceled) 
     
     
         22 . A process for improving at least one of chemical or physical properties of hollow-structure natural fibers, the process comprising:
 providing the hollow-structure natural fibers of animal or vegetable origin to be used either pure or blended together with animal natural fibers, vegetable fibers, polymeric synthetic fibers, man-made natural polymer fibers, continuous filaments of animal origin and/or discontinuous filaments of animal origin, and internal cavities of the hollow-structure natural fibers being in fluid communication with an outside,   providing a substance suitable for improving at least one of the chemical or the physical properties of the hollow-structure natural fibers, and   at least partially internally coating and/or of at least partially filling of the hollow-structure natural fibers with the substance in order to obtain an improvement in at least of the chemical or the physical properties of the hollow-structure natural fibers.   
     
     
         23 . The process according to  claim 22 , further comprising using fibers which have a length of at least 0.01 m as the hollow-structure natural fibers. 
     
     
         24 . The process according to  claim 22 , comprising preparing a solution comprising the substance, and carrying out the at least partially internally coating and/or of at least partially filling of the hollow-structure natural fibers through immersion of the hollow-structure natural fibers in the solution. 
     
     
         25 . The process according to  claim 24 , comprising subjecting the hollow-structure natural fibers to ultrasound treatment during the immersion in the solution. 
     
     
         26 . The process according to  claim 25 , further comprising subjecting the hollow-structure natural fibers to a vacuum so as to take the hollow-structure natural fibers to an external pressure below atmospheric pressure, prior to the immersion of the hollow-structure natural fibers in the solution containing the substance, and carrying out the immersion of the fibers in the solution while the hollow-structure natural fibers are maintained at the external pressure below atmospheric pressure. 
     
     
         27 . The process according to  claim 26 , further comprising using a pressure of between 20% and 90% of atmospheric pressure as the pressure below atmospheric pressure. 
     
     
         28 . The process according to  claim 25 , comprising drying/desiccating the hollow-structure natural fibers, after the removal of the hollow-structure natural fibers from the solution, so as to adhere the substance to the hollow-structure natural fibers. 
     
     
         29 . The process according to  claim 24 , wherein the solution has a pH value of between 4 and 7. 
     
     
         30 . The process according to  claim 25 , wherein the substance is present in the solution at a concentration 0.5-15% w/v. 
     
     
         31 . The process according to  claim 25 , wherein the substance is selected from the group consisting of: chitosan, chitosan oligomer and/or chitosan derivatives. 
     
     
         32 . The process according to  claim 31 , wherein the substance is chitosan, chitosan oligomer and/or chitosan derivatives which have a molecular weight of less than 200,000 Da. 
     
     
         33 . The process according to  claim 31 , wherein the substance is chitosan, chitosan oligomer and/or chitosan derivatives which have a molecular weight of 1,000-5,000 Da. 
     
     
         34 . The process according to  claim 31 , further comprising at least one of a chemical and an ultraviolet ray cross-linking of the chitosan, of the chitosan oligomer and/or of the chitosan derivatives applied to the hollow-structure natural fibers. 
     
     
         35 . The process according to  claim 24 , further comprising ensuring the chemical cross linking of the chitosan, of the chitosan oligomer and/or of the derivatives by addition of citric acid and/or of acrylic monomers to the solution. 
     
     
         36 . The process according to  claim 22 , wherein the substance is selected from the group consisting of: anti-bacterial substances, anti-acari substances, sanitizing substances, perfuming substances, substances to increase a resilience of the fibers and/or substances to increase a breaking resistance of the fibers. 
     
     
         37 . The process according to  claim 22 , further comprising carrying the substance via cyclodextrin, nanocapsules and/or microcapsules. 
     
     
         38 . The process according to  claim 22 , further comprising using kapok fibers as the hollow-structure natural fibers. 
     
     
         39 . The process according to  claim 22 , further comprising using coarse wools of animal hair as the hollow-structure natural fibers, 
     
     
         40 . Use of hollow-structure natural fibers, wherein the internal cavities of the natural fibers are in fluid communication with the outside, pure or blended together with animal natural fibers, vegetable fibers, polymeric synthetic fibers, man-made natural polymer fibers, continuous filaments of animal origin and/or discontinuous filaments of animal origin, for making paddings, yarns, fabrics or unwoven fabrics, wherein the hollow-structure natural fibers are at least partially internally coated and/or at least partially filled by the process according to  claim 25 . 
     
     
         41 . The use of kapok fibers, pure or blended together with animal natural fibers, vegetable fibers, polymeric synthetic fibers, man-made natural polymer fibers, continuous filaments of animal origin and/or discontinuous filaments of animal origin, for making paddings, yarns, fabrics or unwoven fabrics, wherein the kapok fibers are at least partially internally coated and/or at least partially filled by the process according to  claim 25 . 
     
     
         42 . The use of hollow-structure natural fibers according to  claim 40 , wherein the hollow-structure natural fibers have a length of at least 0.01 m. 
     
     
         43 . The use of hollow-structure natural fibers according to  claim 41  wherein the hollow-structure natural fibers have a length of at least 0.01 m.