Unterschiede
Hier werden die Unterschiede zwischen zwei Versionen angezeigt.
| Beide Seiten der vorigen RevisionVorhergehende ÜberarbeitungNächste Überarbeitung | Vorhergehende Überarbeitung | ||
| en:berechnungen:entgasungskennzahlen [2025/01/13 18:30] – neelest | en:berechnungen:entgasungskennzahlen [2026/09/17 12:07] (aktuell) – gelöscht - Externe Bearbeitung (Unbekanntes Datum) 127.0.0.1 | ||
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| - | ======Degassing index calculation====== | ||
| - | Degassing can only take place at the melt surface, with each screw rotation a defined | ||
| - | area is present in the degassing zone. The renewal time oft he pushing flight | ||
| - | indicates how long it takes for the melt to move out and back into the degassing | ||
| - | zone: | ||
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| - | $$t_{Entg.} = \frac{h}{D \cdot π \cdot N \cdot sinφ}$$ | ||
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| - | The degassing surface $A_{pf}$ is the surface of the melt which is in contact with the air | ||
| - | and can degas, divided by the renewal time this gives the surface renewal rate: | ||
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| - | $$A_{Entg.} = i \cdot h \cdot \frac{L}{\sin\varphi}$$ | ||
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| - | The specific surface renewal results from the ratio of the degassing surface to the surface renewal time: | ||
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| - | $$\dot{A}_{Entg.} = \frac{A_{pf}}{t_{pf}}$$ | ||
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| - | {{ : | ||
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| - | The filling level f is calculated for all unpressurised intervals and results in: | ||
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| - | $$f = \frac{\dot{V}_{extruder}}{\dot{V}_{local}}$$ | ||
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| - | A pure drag flow is assumed locally. The filling level corresponds to the melt fraction (blue) in the given figure. | ||
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| - | < | ||
| - | * Schuler, W.: Degassing during polymer production and processing. \\ Tagungsband: | ||
| - | </ | ||
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| - | ===Further topics=== | ||
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