Cooling Time Tips for an Injection molding
This is intended to proved quick insight into cooling time required for a specified thermoplastic resin to solidify during the injection molding process. Specifically the time estimated is the cure time separating the injection and ejection phases of the pr
ocess.
You can use this it to gain insight into how long it will take to make your part and thus, how changes in thickness can affect production capacity and cost.
Calculations are presented for the following two cases:
Plate: An infinite plate of specified thickness.
Rod: An infinite rod of specified diameter.
For both cases, the time calculated is the time for the center of the section to reach the ejection temperature. Quantities required for calculations are as follows:
- Plate Thickness
- Rod Diameter
- Density
- Specific Heat
- Thermal Conductivity
- Mold Temperature
- Melt Temperature
- Ejection Temperature
The cooling model assumes the thermal properties do not change with temperature. This is not really the case but for most scenarios the error will be smaller than that induced by inaccuracies in predicting mold cooling and other issues that may affect ejection..
Obviously, application of this program will require the user to idealize all but the simplest of parts in order to obtain meaningful results. In the end, it is advisable to have a more rigorous cooling analysis completed on any part before finalizing design and commissioning tooling. More information on how this is accomplished may be found in our technical section of the site.