Abstract
In this paper a characteristic value should be found to characterize the fluidity of thermoplastic melts in injection moulding in practical operation. For this purpose a measurement of the filling pressure in the nozzle is executed. The nozzle-filling-pressure found in this way will be compared with other characteristic values, as mould-filling-pressure, nozzle-filling-index and hydraulic-filling-index. Particularly the nozzle-filling-pressure is considered for applicability as a characteristic value mentioned above. Analysis of occupational safety, reproducibility, and replicability should assure the possibility to apply the nozzle-filling-pressure as a value for decontrol.
If all properties are measured at one sample this method offers also the advantage to give a direct relation between the melt-fluidity, shrinkage, optic and mechanical properties.
Additional to the measurements calculations with the simulation-program MOLD FLOW are executed.
Following to this practical research a ”rheological nozzle” has been constructed and built. By measuring the pressure-difference along the nozzle-slot it will be possible to calculate the viscosity and shear rate. The viscosity-results, found out in this way will be compared with viscosity-results determined in a high-pressure-capillary-rheometer. Beside the practical measurements with the ”rheological nozzle” also calculations with the program MOLD FLOW are made to show the rheological and thermodynamic flow–characteristic in the slot core.
If all properties are measured at one sample this method offers also the advantage to give a direct relation between the melt-fluidity, shrinkage, optic and mechanical properties.
Additional to the measurements calculations with the simulation-program MOLD FLOW are executed.
Following to this practical research a ”rheological nozzle” has been constructed and built. By measuring the pressure-difference along the nozzle-slot it will be possible to calculate the viscosity and shear rate. The viscosity-results, found out in this way will be compared with viscosity-results determined in a high-pressure-capillary-rheometer. Beside the practical measurements with the ”rheological nozzle” also calculations with the program MOLD FLOW are made to show the rheological and thermodynamic flow–characteristic in the slot core.
Translated title of the contribution | Measuring of filling-pressure |
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Original language | German |
Qualification | Dipl.-Ing. |
Awarding Institution |
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Supervisors/Advisors |
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Publication status | Published - 22 Mar 1999 |