Apparatus for producing a spun-bonded web from aerodynamically drafted plastic filaments

摘要

Apparatus for the production of a spun-bonded web from aerodynamically drafted thermoplastic filaments. It possesses a spinning head with a plurality of spinneret bores, out of which issues an on the one hand wide and on the other hand at least single-row curtain of thermoplastic, a cooling chamber with a chamber cross-section rectangular in the horizontal direction and decreasing in the direction of run of the filaments, a drafting nozzle connected to the cooling chamber and having a nozzle cross-section which is likewise rectangular in the horizontal direction and which is smaller than the narrowest chamber cross-section, and a set-off at the outlet of the drafting nozzle on at least one drafting-nozzle wall. Connected to the drafting nozzle is a web-laying subassembly in the form of a jet pump with a draw-in resembling a Venturi tube in the vertical direction and a diffuser outlet as well as a flow cross-section rectangular in the horizontal direction and at least one free-air suck-in orifice in the region of the draw-in. A suction blower is arranged in the region of the web-laying subassembly under a continuously moved depositing screen band. The air quantity sucked in by the jet pump can be controlled or regulated by means of the suction blower.