Method of adjusting a heat-displacing T-die

摘要

A novel method of adjusting a heat-displacing T-die is provided wherein a T-die slit gap is adjusted by thermal expansion and contraction of die bolts individually provided with heaters so that a sheet or film material has a target profile in thickness, characterized in that a thickness feed back control loop and a virtual temperature control loop are provided, and in the thickness feed back control loop, data of thickness of products are subjected to a profile treatment to correct a target profile for temperature setting and changing of die bolts so as to define an appropriate slit gap, and in the virtual temperature control loop, an appropriate die bolt temperature is predicted from a control output value of the heater and a radiation temperature to the circumference so as to calculate a corresponding power to be supplied to the heater.