| 摘要 |
Manufacture of filaments of aromatic polyamides having the carbonamide groups in the p-position, e.g. poly-p-phenylene terephthalamide. A spinning mass comprising a mixturé of concentrated sulphuric acid and at least 16%, based on the weight of the mixture, of the aromatic polyamide having an inherent viscosity of at least 3.5 is spun downwardly into a coagulating bath (2) by means of a spinneret head (4), the exit side of which being positioned in a gaseous, inert medium, e.g., air and at a short distance, e.g., 2.5-25 mm above the bath level. The resulting filaments are removed from the bath and subjected to further treatment(s). Formation of funnel shaped-depressions in the coagulation bath is reduced, particularly at increased filament speeds, by dividing the bundle which contains at least 100 filaments into two or more separate and distant groups (12) which are passed into the bath. The bundle may be removed from the bath through a hole positioned below the bath level, said hole being provided with individual passageways for the groups. The dimensions of said passageways may be adjusted from a larger opening during threading-up to a smaller opening at the end of the threading-up procedure without interrupting the spinning process. |
