| 摘要 |
<p>1. Process for the extrusion of a foil (20) possessing a coloured strip with variable colour intensity, in which a first flow (1) of a molten thermoplastic synthetic resin is extruded through a wide slit nozzle (4a) after widening out in the transverse direction to the extrusion direction (P) ans is shaped to a foil (20), with an additional flow of molten thermoplastic synthetic resin being injected into this first melt flow (1) before the latter leaves the nozzle (4a), characterised in that - the injection takes place at a position at which the melt flow (1) has already widened out completely in the direction transverse to the extrusion direction, - with the injected melt flow (2c) possessing a wedge-shaped cross-section and the injection taking place at right angles to the extrusion direction and with corresponding constriction of the first melt flow (1).</p> |
