Patent ID: 9090001
Filing Date: 2015-07-28
Classification: B29C,D01D,D01F,D04H

Abstract:
1. A meltblown process for producing non-woven fabrics with flame-retarding properties from natural cellulose which comprises the following steps: (a) blend raw material comprising wood pulp and solvent of N-methylmorpholine N-oxide (NMMO) to form into a slurry, next additionally mix in as stabilizer 1,3-phenylene-bis 2-oxazoline into the slurry; then, agitate and crush the slurry of wood pulp, N-methylmorpholine N-oxide (NMMO) and 1,3-phenylene-bis 2-oxazoline (BOX) in a horizontal slurry blending machine and under a low temperature in a range between 60 and 80 degrees Celsius, wherein, said wood pulp is pulp cellulose of hard wood or soft wood with an α-cellulose percentage content being over 85% and a degree of polymerization (DP) being in a range between 500-1200; (b) evaporate extra water content from the prepared slurry by a Thin Film Evaporator (TFE) under a temperature in a range between 80 and 120 degrees Celsius, heating for 5 minutes to remove extra water content so that a spinning dope is formed with percentage water content of 5%-13%; (c) by means of meltblown process, the dope is extruded out of a bank of spinnerets to form cellulose filament bundle; (d) by means of an ejecting mist aerosol of water, the filament bundle is coagulated for regeneration, after post treatments of water rinsing, hydro-entangled needle punching and drying have been orderly applied, then nonwoven fabrics are produced from natural cellulose, wherein drying temperature is in a range between 100 and 130 degrees Celsius heating for a time range of 3-5 minutes to form normal natural cellulose nonwoven; (e) roll soaking the normal natural cellulose nonwoven with a flame retardant composition of N-(hydroxymethyl)-3-(methoxy phosphorus acyl) such that the percentage of rolling liquid is in a percentage range between 65%-70% and the concentration of N-(hydroxymethyl)-3-(methoxy phosphorus acyl) is in a range between 250-450 grams per liter (g/L); (f) orderly heat drying, twice baking, neutralizing, soaping clean, water rinse and baking dry the soaking rolled natural cellulose nonwoven, wherein the dry heating is performed under a temperature at 105 degrees Celsius heating for 10 seconds, first bake is performed under temperature in a range between 130 and 155 degrees Celsius heating for a time in a range of 60-120 seconds while the second bake is performed under temperature in a range between 165 and 180 degrees Celsius heating for a time in a range of 60-120 seconds; the neutralizing is performed in an alkaline solution with a concentration of 50 grams per liter (g/L) under a temperature in a range between 20 and 30 degrees Celsius; and the soaping clean is performed in an alkaline solution with a concentration of 2 grams per liter (g/L) having soaping powder concentration of 3 grams per liter (g/L) under a temperature in range between 20 and 30 degree of Celsius for 10 seconds; and (g). Successively alkaline clean, water rinse and dry, then coil the natural cellulose nonwoven from previous step to produce modified natural cellulose nonwoven of long-acting flame retarding properties.