Method and device for extruding a continuous moulded body
The present invention relates to an apparatus and a method as well as a system for extruding continuously molded bodies for producing filaments or staple fibers from an extrusion solution, such as a cellulose solution containing water, cellulose and tertiary amine oxide such as N-methylmorpholine N-oxide. In comparison with the methods known from the prior art, profitability can be increased in the production of continuously molded bodies ( 3 ) if the extrusion rate v is set to a value v=B·T 0.33 ·10,000·(1/r 2 ). In a system, profitability can be enhanced if the number r of rows is r=[(B/v)·10,000·T 0.33 ] 1/2 . T is here the fiber titer in T dtex, v the extrusion rate in m/min, r the number of the rows of extrusion duct orifices ( 12 ), and B an operational parameter which is not more than 4 and at least 0.5.
1. A method for extruding a continuously molded body for producing a filament or a staple fiber from an extrusion solution containing water, cellulose and tertiary amine oxide, the method comprising
passing the extrusion solution through a plurality of extrusion ducts of at least one extrusion head to an extrusion duct orifice, the extrusion ducts being arranged in a predetermined number of rows,
extruding the extrusion solution through the extrusion duct orifices at an extrusion rate v to produce an extruded, continuously molded body;
passing the extruded, continuously molded body through an air gap,
wherein the extrusion rate v in m/min is a function of the number of rows r the fiber titer T in dtex, and an operational parameter B, and is given by
v=B·T 0.33 ·10,000·(1 /r 2 ),
where the operational parameter B has a value of not more than 4.
2. The method according to claim 1 , wherein the operational parameter has a value of not more than 3.5.
3. The method according to claim 1 , wherein the operational parameter has a value of not more than 3.
4. The method according to claim 1 , wherein the operational parameter has a value of at least 0.5.
5. The method according to claim 1 , further comprising
discharging the continuously molded body from the extrusion head through the air gap in the form of a curtain.
6. The method according to claim 5 , further comprising
passing the continuously molded body as a curtain through a precipitation bath.
7. The method according to claim 5 , further comprising
deflecting the curtain in a precipitation bath.
8. The method according to claim 7 , further comprising
converging the deflected curtain outside the precipitation bath towards substantially one point.
9. The method according to claim 1 , further comprising
passing the continuously molded body for producing a filament or a staple fiber from an extrusion solution in the air gap through substantially stagnant air.