Patent Report: Moretto material drying hopper

A hopper that better communicates with the press to determine material flow in real time could help ensure the optimal drying of hygroscopic resins, according to a patent application filed by Moretto SpA.

The Massanzago, Italy, auxiliary equipment maker envisions a drying system equipped with an electronic control unit that regulates airflow through a hopper. The invention would address current concerns that the calculations for factors such as drying time and airflow rates are imprecise.

According to the application, current drying technologies use estimates of hourly throughput to determine the residence time of resins in the hopper, or use data captured by load cells. Neither approach is exact. “Due to the variability of the conditions of the transforming machine, the dehumidification process may not be completely satisfactory,” it says. It continues, “the need to improve the regulation of the dehumidification airflow according to the actual operating conditions ... is therefore very much felt, in order to increase the energy efficiency of the process.”

Moretto’s proposed control unit would send a signal to valves on the air port of the hopper to optimize airflow. In one embodiment of the invention, the control unit would be in communication with an electrical output channel on the press that provides real-time data about the duration of the molding cycle. The output channel would detect the movements of the mold as it opens and closes, allowing the control unit to make real-time adjustments to the drying cycle as necessary.

Based on the data, the control unit could even determine which dry-air generators would be most appropriate to use.

“Thereafter, the electronic control unit sends a signal to the dry air generators and to the partialization valves so as to optimize the airflow rate in each hopper as a function of the energy actually required for dehumidification,” the application states.

Patent application 20190030774; published Jan. 31