Method and system for the application of chemical compounds to natural fibers and treated fibers obtained therefrom

Abstract

There is provided an impregnated natural fiber including a cuticle and an interior lumen, the cuticle circumscribing the interior lumen; and insoluble particulates possessing a preselected property embedded in the fiber. The particulates comprise at least 0.1-30 wt. % of the impregnated fiber and the particulates are embedded on the cuticle and within the lumen of the fiber. The fiber has an increased strength, micronaire value and rate of water absorption. Also provided is a system for surface treating cellulose sliver fibers. The system includes a vessel containing a moist paste which comprises at least one particulate material possessing one or more preselected desired properties, a thickening agent and water. The paste from the vessel is dispensed directly onto sliver fiber ribbon(s). A bore sonotrode generates ultrasonic waves which embed the particulate material(s) in the sliver fibers.

I claim: 
     
         1 . A method for impregnating sliver fibers with insoluble particulates, comprising the steps of:
 a. obtaining a paste comprising:   
       i. at least one insoluble particulate material having a preselected desired property; 
       ii. water; and, 
       iii. a thickening agent; 
       b. providing at least one ribbon of sliver fibers; 
       c. dispensing the paste on the at least one sliver fiber ribbon; and 
       d. conveying the paste-coated at least one sliver fiber ribbon through a sonotrode and so that ultrasonic waves are transmitted through the at least one sliver fiber ribbon so that the at least one insoluble particulate material in the paste on the at least one sliver fiber ribbon is embedded in the ribbon, thereby imparting the desired property of the at least one particulate material to the sliver fibers. 
     
     
         2 . The method of  claim 1 , wherein the sonotrode is a bore sonotrode having a plurality of bores, through which the sliver fiber ribbon is conveyed. 
     
     
         3 . The method of  claim 1 , further comprising a step of constraining or folding the at least one sliver fiber ribbon so that it is compressed so that the fibers of the ribbon cannot separate and disperse. 
     
     
         4 . The method of  claim 1 , further comprising a step of releasing or unfolding the constraining or folded at least one sliver fiber ribbon. 
     
     
         5 . The method of  claim 1 , further comprising a step of contacting a deaerating solution to the at least one sliver fiber ribbon prior to said step of dispensing. 
     
     
         6 . The method of  claim 1 , further comprising a step of washing the at least one sliver fiber ribbon to remove excess paste from the ribbon. 
     
     
         7 . The method of  claim 1 , wherein the sonotrode is operated between about 500 W to about 3000 W and between about 15 kHz to about 30 kHz. 
     
     
         8 . The method of  claim 1 , wherein the sonotrode is operated between about 1000 W to about 2000 W and between about 15 kHz to about 25 kHz. 
     
     
         9 . The method of  claim 1 , further comprising a step of bleaching and/or optically whitening the at least one impregnated sliver fiber ribbon. 
     
     
         10 . The method of  claim 1 , wherein the at least one insoluble particulate material is selected from an element, a compound, a composition and any combination of the above. 
     
     
         11 . The method of  claim 1 , wherein the resultant impregnated fiber sliver can be used directly for producing yarn without a second carding operation. 
     
     
         12 . The method of  claim 10  wherein the at least one insoluble particulate material is selected from the group consisting of silver oxides, copper oxides, magnesium oxide, zinc oxide, various zeolites or ceramic compounds, and combinations thereof. 
     
     
         13 . The method of  claim 12  wherein the at least one insoluble particulate material is copper oxide. 
     
     
         14 . The method of  claim 1  wherein the thickening agent is selected from the group consisting of: nanocellulose, fumed silica, guar gum, algicinic acid and salts thereof, agar, locust bean gum, pectin, and gelatin. 
     
     
         15 . The method of  claim 1  wherein the paste has a viscosity of from 650 to 1000 centipoise at room temperature. 
     
     
         16 . The method of  claim 5  wherein the deaerating agent comprises ethylene oxide. 
     
     
         17 . The method of  claim 5  wherein the deaerating agent comprises a polysiloxane. 
     
     
         18 . The method of  claim 1  wherein the paste comprises insoluble particulate material in the range of from 27 to 33% by weight. 
     
     
         19 . The method of  claim 1  wherein the preselected desired property is an antibacterial property.