The Average temperature result shows the average bulk temperature through the thickness of the part at the end of fill.
The temperature of polymer melt changes not only with time and location, but also with thickness during the entire injection molding cycle. It is difficult to illustrate all these changes in a single display. Instead, the average temperature is used to indicate its weight across the thickness. Average temperature represents the energy that is transported through a particular location at a specific time.
Hot spots, which are due to excessive viscous heating during the filling stage, are indicated on the average temperature contour.
You can use the Average temperature result as an alternate way of examining the flow distribution. Areas with continuous flow (heat convection) typically have a higher Average temperature, which drops quickly when the flow in that area stops. If the Average temperature is too low in a thin area of the part, hesitation or short shots can occur. If the Average temperature is too low in an area where weld lines are present, the weld lines may be worse.
In areas where the Average temperature is too high, material degradation and surface defects may occur. To alleviate this, make sure the Average temperature is always within the recommended temperature range for the polymer you are using. You may also consider redesigning the part geometry near the hot spot or changing the process conditions. Differential temperature can also cause non-uniform shrinkage and warpage.
The Average temperature result should be examined in conjuction with the Frozen layer fraction at end of fill result. Any section of the mold with an average temperature that is below the material transition temperature, and a frozen percentage of greater than 25percent may not be packed properly, which can lead to shrinkage and warpage problems.
A number of options are available to improve this result. Alterations usually have side effects so after making changes, you should check to see whether other problems have been caused.
| Temperature too low | Possible problems |
|---|---|
| Increase the melt temperature. |
|
| Increase mold temperature. | May increase cycle time. |
| Decrease injection time. | May cause excess shear in the gate if it is restrictive. Too much shear will cause degradation and surface defects. |
| Increase the thickness in the area to permit flow. | May cause a functional problem with the design and increase cost. |
| For hesitation in thin areas. | See Hesitation. |
| Move the gate away from the hesitation area. | May cause hesitation or other problems elsewhere in the part. |
| Temperature too high | Possible problems |
|---|---|
| Increase the injection time | May increase cycle time. |