Processing method of natural cellulose fiber intrinsically with enhanced antiseptic, deodorant and negative-ion features from bamboo

Abstract

The present invention provides a processing method of natural cellulose fiber intrinsically with enhanced antiseptic, deodorant and negative-ion features from bamboo. The process uses mixture of wasted coffee residue and bamboo pulp as raw material. The process uses N-methylmorpholine N-oxide (NMMO) as primary solvent and 1, 3-phenylene-bis 2-oxazoline (BOX) as additive stabilizer. A cellulose solution is firstly formed by the wasted coffee residue, bamboo pulp, NMMO and BOX aforesaid. Secondly, via grinding, blending, dissolving and thermal dehydrating, the cellulose solution is converted into spinning dope. Thirdly, spin the dope obtained previously by dry-jet wet spinning method and coagulate and regenerate in a coagulation bath to form into threads. Finally, rinse, desiccate and lubricate the regenerated threads obtained previously as well as wind it up to produce reeled natural bamboo cellulose fiber with enhanced antiseptic, deodorant and negative-ion features.

What is claimed is: 
     
         1 . A processing method of natural cellulose fiber intrinsically with enhanced antiseptic, deodorant and negative-ion features from bamboo comprises following steps:
 a. Material Selection and Preparation: Select bamboo pulp and wasted coffee residue as raw material to blend together mutually into a mixture, preferably the cellulose content of the bamboo pulp being over 80% and the range for degree of polymerization (DP) being 400-800 while the wasted coffee residue having been ground into range of 500 nm-1000 nm (nano-meter) granules in high speed mode;   b. Dope Blending and Dissolution: By putting N-methylmorpholine N-oxide (NMMO) as primary dissolving solvent and 1,3-phenylene-bis 2-oxazoline (BOX) as additive stabilizer into prepared bamboo pulp mixture obtained from previous step a for blending and dissolving under low temperature between 60 degree of Celsius and 80 degree of Celsius (60° C.-80  rapid grinding of a horizontal dope blending machine;   and, by means of cellulose features of high expanding, moistening and dissolving ability as well as high rate of dissolving speed affected by the N-methylmorpholine N-oxide (NMMO) to expedite mutually blending and dissolving effect for forming a slurry; then, dehydrate it via heating up to temperature between 80 degree of Celsius and 120 degree of Celsius (80  ° C.) by vacuum thin film evaporator (VTFE) for 5 minutes to decrease water content thereof down to in range down of 5-13% so that a homogenized mucilaginous dope is formed;   c. Spinning and Thread Formation: Spin the dope obtained from previous step b by dry-jet wet spinning method, wherein the dope is fed into a die assembly and forcedly extruded out of spinnerets into the spinning machine for spinning and coagulation bath for coagulating and regenerating via a quantitative metering gear pump to form thread bundle of bamboo cellulose, wherein certain hot air is continuously fed therein for circulation around peripheral thereof then discharged out via surrounding of the spinnerets; and   d. Finishing and Fiber Formation: Rinse, desiccate and lubricate the regenerated threads obtained from previous step c as well as wind it up to produce reeled natural bamboo cellulose fiber with enhanced antiseptic, deodorant and negative-ion features such that the resultant fiber product is wound into continuous filament yarn.   
     
     
         2 . The processing method of natural cellulose fiber intrinsically with enhanced antiseptic, deodorant and negative-ion features from bamboo as recited and claimed in  claim 1 , wherein step a above, the weight content of the wasted coffee residue in the prepared bamboo pulp mixture is in range of 0.5 wt %-5 wt %. 
     
     
         3 . The processing method of natural cellulose fiber intrinsically with enhanced antiseptic, deodorant and negative-ion features from bamboo as recited and claimed in  claim 1 , wherein in step b above, the range for the concentration of the N-methylomrpholine N-oxide, (NMMO) is 50%-75%. 
     
     
         4 . The processing method of natural cellulose fiber intrinsically with enhanced antiseptic, deodorant and negative-ion features from bamboo as recited and claimed in  claim 1 , wherein in step d above, the desiccating process is undertaken with temperature range in 100 degree of Celsius and 150 degree of Celsius (100° C.-150 ° C.). 
     
     
         5 . The processing method of natural cellulose fiber intrinsically with enhanced antiseptic, deodorant and negative-ion features from bamboo as recited and claimed in  claim 1 , wherein in step d above, the winding speed of the winding process is in range of 200-800 meter per minute. 
     
     
         6 . The processing method of natural cellulose fiber intrinsically with enhanced antiseptic, deodorant and negative-ion features from bamboo as recited and claimed in  claim 1 , wherein in step d above, the range for the fiber tenacity of the bamboo cellulose fiber is 1.5 g/d-4.0 g/d. 
     
     
         7 . The processing method of natural cellulose fiber intrinsically with enhanced antiseptic, deodorant and negative-ion features from bamboo as recited and claimed in  claim 1 , wherein in step d above, the range for the fiber elongation rate of the bamboo cellulose fiber is 4.0%-8.0%. 
     
     
         8 . The processing method of natural cellulose fiber intrinsically with enhanced antiseptic, deodorant and negative-ion features from bamboo as recited and claimed in  claim 1 , wherein in step d above, the range for the fiber Young's modulus of the bamboo cellulose fiber is 50 g/d-150 g/d. 
     
     
         9 . The processing method of natural cellulose fiber intrinsically with enhanced antiseptic, deodorant and negative-ion features from bamboo as recited and claimed in  claim 1 , wherein in step d above, the regenerated threads obtained is further processed to rinse, desiccate and lubricate as well as cut into staple fiber in accordance with the requirements specified. 
     
     
         10 . The processing method of natural cellulose fiber intrinsically with enhanced antiseptic, deodorant and negative-ion features from bamboo as recited and claimed in  claim 1 , wherein in step d, the procedure for the recovery of the primary NMMO dissolving solvent includes steps as below:
 A. Bleach: adopting absorption method of the suspended active carbon: Put 0.05%-0.10% active carbon powder of good absorptivity and suspension ability into the solution of NMMO solvent to be de-colored, then alternate the air-blast mixing absorption and the stationary suspending absorption treatments in treating time ratio is 1:3 to 1:6 for 8 hours to finish the bleaching procedure so that not only the related equipments can be simplified but also the energy can be saved as well as the bleaching effect can be promoted;   B. Filtration: adopting two filtering stages: First coarse filtering stage: for simplifying the equipment, general cartridge filter is used together with the auxiliary filtering agent, which is pre-coated over the surface of the cartridge filter, and put 0.03%-0.05% of leavening agents into the liquid to be filtrated for not only preventing the active carbon from accumulating on the surface thereof in hindering the filtering speed but also regularly maintaining filtering effect of high performance without decay; The composition of said auxiliary filtering agent is preferably made of diatomite and cellulose in ratio of 4:1; After completion of the coarse filtering stage, the filtering dregs and residual liquid are centrifugal and dehydrating treated for recovery so that the residual auxiliary filtering agent dehydrated is reused as auxiliary filtering effect being remained; and Second fine filtering stage: by means of fine filter UF, the purity of the filtered liquid is the same as fresh NMMO solvent;   C. Condensation: concurrently combining two condensing methods: To recover the rinsing liquid in the present invention, the condensing load in dehydration is very large in manner of approximately 90 tons per ton of fiber as solvent concentration must be condensed from range of 6.5%-8.0% to range of 50% -55%; For low yield quantity of fiber, the tri-effect condensing method is adopted to dehydrate per ton of rinsing liquid in using 0.5 ton of steam (high steam consumption, low electric power consumption); For high yield quantity of fiber, the Mechanical Vapor Recompression (MVR) condensing method is adopted to dehydrate per ton of rinsing liquid in using 0.003-0.03 ton of steam (low steam consumption, high electric power consumption); The yield condensed solvent and water in both foregoing condensing methods are also completely recovered for reusing though each condensing method is only suitable for different specific yield quantity of fiber; Wherein, the yield condensed solvent is reused as processing solvent and yield condensed water is reused to rinse fiber; and   D. Refinement: adopting oxidation and neutralizing reduction under low temperature of 80 degree of Celsius (80° C.): Using 35% hydrogen peroxide (H2O 2 ) as oxidant and 85% hydrazine hydrate (N2H4.H2O) as neutralizing reductant, the result is measured by electric potential titrating method; the NMMO content is decreased down below 10 ppm so that not only the purity of NMMO is promoted but also the NMMO consumption is decreased.