Problem in drying plastic?

Although the drying of plastic particles is a relatively simple process, in some cases, the particles cannot be completely dried and exploded. Factors affecting drying effect include:

-Drying temperature:
Heat is the key to opening the resultant force between water molecules and hygroscopic polymers. When it is higher than a certain temperature, the gravitational force of water molecules and polymer chains will be greatly reduced, and the water vapor will be taken away by dry air.

-Dew point:
In the dryer, wet air is first removed to contain very low residual moisture (dew point). Then, reduce its relative humidity by heating the air. At this time, the steam pressure of dry air is low. By heating, the water molecules inside the particles get rid of the binding force and diffuse to the air around the particles.

-Time:
In the air around the particles, it takes a certain time for heat absorption and water molecules to diffuse to the particle surface. Therefore, the resin supplier shall specify the time required for a material to be effectively dried at appropriate temperature and dew point.

-Air flow:
The dry hot air transfers the heat to the particles in the drying hopper, removes the moisture on the surface of the particles, and then sends the moisture back to the dryer. Therefore, there must be enough air flow to heat the resin to the drying temperature, and maintain this temperature for a certain time.

When the problem of poor drying occurs, the problem should be found from the dryer condition.

Dryer condition：

When checking the dryer, pay special attention to the air filter and hose. Blocked filters or flattened hoses will reduce the air flow, thus affecting the operation of the dryer. Damaged filters will pollute the desiccant and inhibit its moisture absorption capacity. Broken hoses may empty the humid environment
The air is introduced into the drying air stream, causing premature moisture absorption and high dew point of the dryer; The combination of the hose with poor insulation measures and the dry hopper will also affect the drying temperature.