초록 ▼

An extruder control system and method controls melt temperature to maintain viscosity of the melt at the die. A constant volumetric flow to the die is delivered by a gear pump, the die is a fixed orifice, and pressure between the gear pump and the die is indicative of viscosity. Changes in pressure

An extruder control system and method controls melt temperature to maintain viscosity of the melt at the die. A constant volumetric flow to the die is delivered by a gear pump, the die is a fixed orifice, and pressure between the gear pump and the die is indicative of viscosity. Changes in pressure are sensed and compensating changes in temperature are effected to return the pressure and, hence, the viscosity to its previous value.

대표청구항 ▼

A method of extruder viscosity control for an extruder used in the manufacture of continuously extruded articles including the steps of providing a controlled volumetric flow of thermoplastic material to be extruded to a die by provision of a controlled volumetric flow means upstream of the die with

A method of extruder viscosity control for an extruder used in the manufacture of continuously extruded articles including the steps of providing a controlled volumetric flow of thermoplastic material to be extruded to a die by provision of a controlled volumetric flow means upstream of the die with respect to the flow of the material to be extruded, detecting pressure variations in the flowing material intermediate the controlled volumetric flow means and the die, and altering the temperature of the material flowing to the die to be extruded to hold the pressure relatively constant, whereby the viscosity of the material to be extruded is held substantially constant at the die.