Control of key parameters in the drying process

In the drying process, drying temperature and time are two key parameters that need to be strictly controlled. Drying temperature is too high or too long, may lead to overheating decomposition of the material, affecting product quality; drying temperature is too low or time is too short, can not completely remove moisture, will also affect product quality.

Drying temperature

The selection of drying temperature should be based on the thermal properties of PET resin and the moisture content of the material to determine. Usually, the drying temperature should be higher than the dew point temperature of the material, but lower than the thermal decomposition temperature of the resin. For PET masterbatch, the drying temperature is generally between 80-120℃.

Drying time

The length of drying time depends on the moisture content of the material, the drying temperature and the performance of the drying equipment. Generally speaking, the higher the moisture content, the longer the drying time; the higher the drying temperature, the shorter the drying time. However, it should be noted that the drying time should not be too long, so as not to overheat the material decomposition. In actual production, should be tested and adjusted according to the specific circumstances to determine the best drying time.

Fourth, the choice of drying equipment and maintenance

The choice of drying equipment has an important impact on the drying effect. Common drying equipment are hot air circulation oven, far infrared oven, vacuum oven and so on. Hot air circulation oven has a simple structure, easy to operate, uniform heating and other advantages, suitable for most materials drying. Far-infrared oven is the use of far-infrared radiation, fast heating speed, low energy consumption, but the cost of equipment is higher. Vacuum oven is suitable for temperature and oxygen sensitive materials.

Maintenance of drying equipment is equally important. Regularly clean up the dust and debris inside the dryer to keep the equipment clean and ventilated; check the working status of the heating element and temperature control system to ensure the accuracy and stability of the drying temperature; regularly check the sealing performance of the dryer to prevent the entry of outside air to affect the drying effect.

V. Conclusion

Drying plays a vital role in the preparation process of PET masterbatches. Through drying treatment, the moisture in the material can be removed to prevent the occurrence of hydrolysis reaction; improve the extrusion efficiency, improve the dispersion of masterbatches; prolong the shelf life of the product and improve the quality of the product. In actual production, the drying temperature and time should be strictly controlled, choose the appropriate drying equipment, and regular maintenance and repair of equipment. Only in this way can we ensure that the preparation process of PET masterbatches goes smoothly and produce high-quality PET masterbatches to meet the needs of the plastic products industry.