Barrel Heat Control Is 10X More Accurate

A new approach to controlling heater bands on an extruder barrel reportedly prevents temperature swings caused by a delay between a temperature probe signal and a heater band’s response.

A new approach to controlling heater bands on an extruder barrel reportedly prevents temperature swings caused by a delay between a temperature probe signal and a heater band’s response. Davis-Standard Corp., Pawcatuck, Conn., patented the new algorithm, which “stores a collection of previously calculated control setpoints for maintaining a given temperature at a particular screw speed,” according to U.S. Patent #6755564. It then adjusts temperature based on the extruder’s previous thermal experience at that screw speed.


Temperature control is said to be within ±0.1° F. The new temperature-reset function is for use with Davis-Standard’s dual-probe temperature control system, which averages two thermocouple measurements, one on the surface of the barrel wall, the other inside the heater. It’s available with Davis-Standard’s EPIC III and MESA III supervisory controls.