In the plastic processing industry, some products will have bad situations, like shrinkage, silver lines, bubbles, cracks, flow marks, poor transparency, etc. The main reason for these poor qualities is that the plastic is not sufficiently dried before molding. For materials with high hygroscopicity such as PA, PET, PC, PBT, and CA, the traditional hot air dryer is unable to completely dry them due to the penetration of moisture into the plastic particles.
The feed composition of the dehumidifying dryer combines dehumidification, drying, and two-stage feeding functions. The one-piece design ensures that the material is dried in a completely closed system to prevent the dried material from being re-moistened due to contact with the outside air. This way can achieve a good drying effect.
The runner of the dehumidifying dryer (standard type) adopts imported high-density, high-performance titanium silicon, and molecular sieve composite dehumidifying wheel. The whole runner is a highly effective absorbent, which can absorb 100% humid air without shedding or deforming. It has a long service life and can be cleaned many times.
The runners are divided into a hygroscopic area, a removal area, and a regeneration area. After the moisture in the air is adsorbed on the runner in the hygroscopic area, the dried air is continuously sent out. At the same time, the runner that has absorbed the moisture rotates to the regeneration area, and the recycled air sent from the opposite direction completely removes the moisture adsorbed on the runner. The dew point can reach below -40°C by a special combination.
For hygroscopic plastics, moisture will enter the plastic particles to form molecular bonds, but these plastics can only be used to remove moisture from hot and humid air. The dehumidifying dryer provides the dry airflow to the hopper, which is dehumidified by a molecular sieve with extremely high adsorption of water molecules, reducing the dew point of the air, and then heats the air into the hopper. With these, the working airflow has three main elements needed to dry the plastic: flow rate, temperature, and low dew point.
When this airflow passes through the hopper, the moisture on the plastic surface can be evaporated and taken away. It can also remove the crystal water inside the plastic molecules to meet the requirements before plastic processing and molding.