| 摘要 |
The invention relates to a measuring nozzle for determining the extensional viscosity of polymer melts while processing the polymer melts, comprising a flow channel which has a rectangular cross-section and which has a transitional section (3) between an inlet section (1) and an outlet section (2) with respective constant cross-sections. The transitional section tapers hyperbolically in the flow direction (8) between two opposing channel walls (6 or 7). The aim of the invention is to achieve advantageous measuring conditions. This is achieved in that the transitional section (3) comprises an inlet-side zone (4), in which the mutual distance between the two channel walls (7) between the two hyperbolic channel walls (6) decreases constantly in the flow direction (8), and an outlet-side zone (5) which adjoins the inlet-side zone and in which two of the channel walls (6, 7) lying opposite one another in pairs run parallel to each other while the two channel walls (7) arranged therebetween converge hyperbolically in the flow direction (8). |
