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Temperature profile
Visualisation of the temperature curve
Interpretation of the curves
- ** Red curve: The red curve represents the average melt temperature of the melt vortex. It begins with the temperature of the melt film (start temperature), which lies between the melting temperature and the barrel temperature. Typically, the temperature rises continuously, but can theoretically also fall due to correspondingly low barrel temperatures. * ** Blue curve: The blue curve represents the progression of the specified Internal cylinder wall temperature. The temperature is interpolated linearly between the specified heating zones.
Depending on the process, the following additional curves are added:
- Green curve: In barrier zones, the temperature in the melt and solids channel is considered separately. The red curve corresponds to the temperature in the solids channel and the green curve to the temperature in the melt channel. At the end of the barrier, the temperature curve (in red) follows the end of the temperature curve in the melt channel (green).
- Orange curve: For shear parts, the temperature above the shear web is also shown. This is always higher than the average temperature and always corresponds at least to the heating zone temperature.
- Purple curve: For a internally tempered screw, the temperature at the base of the screw is also calculated.
Analysis of the temperature curve
- Temperature curve (red and green curve): As a rule, the lowest possible outlet temperature is desirable for an energy-efficient process. The higher the temperature, the sooner and faster thermal damage to the plastic occurs. A greater thermal inhomogeneity can also be assumed. However, a high melting rate is usually accompanied by a high temperature. An optimised process therefore delivers a high melting rate at a low outlet temperature
- Heating zone temperature (blue curve): The cylinder temperatures must be selected so that a high melting rate can be achieved at the lowest possible outlet temperature. The temperature difference between the melt and the barrel should not be too great, especially in the rear part of the screw, as an inhomogeneous temperature distribution can be assumed in this case.
- Screw base temperature (purple curve): With an internally tempered worm, the temperature at the base of the worm is significantly cooler than the mean temperature. The greater the temperature difference between the base of the snail and the mean temperature, the more inhomogeneous the temperature distribution.