Page 97 - Injection Molding Advanced Troubleshooting Guide
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82 9 Drying
To ensure adequate drying it is critical to have all four of these conditions met.
Four hours of drying time is meaningless if the temperature requirement is not
met. A typical desiccant dryer will provide an air dew point of −40 °F. Keep in mind
that the dryer temperature will help release the moisture from the pellets, the low
dew point will allow the air to pick up the moisture, and the air flow exposes more
of the pellets to the warm/dry air. Figure 9.1 shows an example of a typical drying
hopper.
Figure 9.1 Typical drying hopper
There are many ways that incomplete drying can occur that relate back to the four
key drying parameters.
