Molding tool and method for producing a molding tool for extruding cellulose molded bodies

Abstract

The invention relates to a molding tool (1, 51) for the extrusion of cellulosic molded bodies (4) from a spinning dope (2), having an entry side (6, 56) and an exit side (7, 57) for the spinning dope (2), with at least one nozzle body (8, 58a, 58b, 58c) including a planar carrier (9, 59a, 59b, 59c) with extrusion openings (10, 60) that penetrate the carrier from the entry side (6, 56) to the exit side (7, 57) and have a mouth diameter (12, 62) at the exit side (7, 57) and through which the spinning dope (2) is extruded into the cellulosic molded bodies (4). In order to provide a molding tool of the afore-mentioned type, which is easier and more inexpensive to manufacture while providing excellent strength and pressure stability at the same time, it is proposed that the ratio of the thickness (13, 63) of the carrier (9, 59a, 59b, 59c) to the mouth diameter (12, 62) of the extrusion openings (10, 60) at the exit side (7, 57) be at least 6:1, preferably at least 10:1, and that the extrusion openings (10, 60) be formed in the carrier (9, 59a, 59b, 59c) by applying laser energy.

1 . A molding tool for the extrusion of cellulosic molded bodies from a cellulose-containing spinning dope comprising an entry side and an exit side for the cellulose-containing spinning dope, with at least one nozzle body including a planar carrier with extrusion openings that penetrate the carrier from the entry side to the exit side and have a mouth diameter at the exit side and through which the cellulose-containing spinning dope is extruded into the cellulosic molded bodies, wherein a ratio of the thickness of the carrier to the mouth diameter of the extrusion openings at the exit side is at least 6:1, and that the extrusion openings were formed in the carrier by applying laser energy. 
     
     
         2 . The molding tool as claimed in  claim 1 , wherein the carrier has a thickness of at least 600 μm. 
     
     
         3 . The molding tool as claimed in  claim 1 , wherein the extrusion openings are burr-free at the exit side. 
     
     
         4 . The molding tool as claimed in  claim 1 , wherein the at least one nozzle body is annular or rectangular. 
     
     
         5 . The molding tool as claimed in  claim 1 , wherein the molding tool comprises several nozzle bodies. 
     
     
         6 . The molding tool as claimed in  claim 1 , wherein the molding tool further comprises at least one first web which is firmly connected to the at least one nozzle body by material bonding and protrudes from the at least one nozzle body towards the entry side. 
     
     
         7 . The molding tool as claimed in  claim 6 , wherein the molding tool further comprises at least one second web, wherein the nozzle body extends between the at least one first web and the at least one second web. 
     
     
         8 . The molding tool as claimed in  claim 6 , wherein at least portions of the at least one first web extend essentially normal to the nozzle body. 
     
     
         9 . The molding tool as claimed in  claim 7 , wherein a distance normal to a lengthwise extension of the at least one nozzle body between the at least one first web and the at least one second web is at least less than 100 times the thickness of the carrier. 
     
     
         10 . The molding tool as claimed in  claim 7 , wherein the at least one first web fully encircles the at least one second web. 
     
     
         11 . The molding tool as claimed in  claim 6 , wherein, at the entry side, the molding tool further comprises a flange with at least one flange limb, the flange limb adjoining the web and protruding outward from the molding tool. 
     
     
         12 . A method for producing a molding tool as claimed in  claim 1 , comprising forming the extrusion openings in the carrier by applying laser energy to it from the entry side of the molding tool, and creating at the exit side, burr-free extrusion openings in the carrier without any further finishing. 
     
     
         13 . The method as claimed in  claim 12 , further comprising as a final procedural step, forming the extrusion openings in the carrier. 
     
     
         14 . A method for producing regenerated cellulose molded bodies, comprising extruding the cellulose-containing spinning dope through the molding tool as claimed in  claim 1  and precipitating in a spinning bath in order to produce the cellulosic molded bodies. 
     
     
         15 . The method as claimed in  claim 14 , wherein the cellulose-containing spinning dope comprises a tertiary amine oxide in which the cellulose is dissolved and the spinning bath includes a mixture of water and tertiary amine oxide. 
     
     
         16 . The molding tool as claimed in  claim 1 , wherein the ratio of the thickness of the carrier to the mouth diameter of the extrusion openings at the exit side is at least 10:1. 
     
     
         17 . The molding tool as claimed in  claim 2 , wherein the thickness of the carrier is at least 800 μm.