Extruder SOP

Primary Equipment:
Created: February 24, 2009 by Bob Cox

Revised: August 10, 2010 by Bob Cox

University of Utah, Chemical Engineering


  1. DO NOT PRESS RED POWER BUTTON ON THE EXTRUDER UNTIL DIE TEMPERATURE AND ZONES 1-3 ARE > 130 DEGREES C -THE MELT POINT MUST BE AT LEAST 130 DEGREES C. The red button applies power to the screw; if you power the screw when the polymer is solid you will break the shear pin! Extra shear pins are in the storage cabinet below the extruder.
  2. Extruder Polymer is VERY HOT! Use gloves and metal tongs when handling extruder polymer.


  1. Turn on main air pressure and water valves for cooling.
  2. Verify that toggle switch on Extruder by RPM dial is set at remote.
  3. Open water-cooling valves to hopper, flow should be set at 0.5-g.p.m. Cooling water is not required for the take-up rollers.
  4. Set the main power and heat zone toggle switches on the lower control panel to the off position, they do not affect Opto control.
  5. Switch the three air control solenoid toggle switches located on the right side of the extruder control panel to the on position. These switches must be on in order for Opto to control the coolant airflow.
  6. Open Opto Control from the short cut on the desktop.
  7. Opto can be operated in either manual or auto mode. Normal operation is in AUTO Mode. A description of manual mode operation is given for reference.
  8. To operate in manual mode:
    1. Set all control windows to manual � the �M� should be displayed in each control window.
    2. Set the manipulated variable (MV) to the desired value. In manual mode the PID values have no effect.
    3. Use the (MV) to control temperature by setting the % power on. The set point will track the MV. A set point of 12% (MV) in manual mode is approximately 150 degrees C.
    4. For initial heating of extruder and steady state operation, keep value of MV for cooling equal to zero.
  9. Verify that the screw speed control is in manual mode and that the MV is set to zero.
  10. Polymer fumes are toxic. Closely monitor temperatures to avoid burning polymer.
  11. For operation in Auto mode: Set all control windows except speed control to Auto, speed control should remain in manual mode and set to zero until melt point reaches 130 degrees C and die temperature is at least 160 degrees C.
  12. Set the set point (SP) to the desired value. Set zone two at zero, it will heat from zones one and three. Set temperature set points for zones one and three to 150 � 220 degrees C, 170 is optimal. Zones one and three should heat within 20 � 30 minutes. Set Die Temperature to 180degrees C, in auto mode.
  13. Speed Control: When die and zones 1 � 3 reach 150 degrees Celsius you are ready to attempt to extrude. The melt point may be less than 150 degrees, it must be at least 120 degrees C. Verify that the speed control set point is zero, set speed control to auto mode. Now push the red button on the extruder and observe torque meter on extruder, torque should never exceed 600. Gradually increase speed setting (SP) on the computer to desired value, starting at 1 RPM and slowly increasing as you monitor torque. As torque approaches 600 Opto will automatically reduce speed. Opto control is not fast enough to prevent breaking the shear pin so keep the torque well below 600.

Note: For the speed setting in auto mode, the (SP) is in RPM, in manual mode (MV) is in % power.

Data is in extruder data file on C: drive.

Extruder Operation: Refer to Extruder manual available in stock room for further details.

Shutdown procedure:

  1. Turn off power to extruder motor � Press red button on extruder, light should be off.
  2. If operating in manual mode set coolant MV to 100% and wait until all temperature zones are 70 degrees Celsius or less.
  3. For operation in Auto mode: Adjust set point to 27 degrees C, verify coolant air is flowing. Do not shut down Opto until coolant solenoids have shut off and all zones are below 70 degrees Celsius, this takes about 30 minutes.
  4. Exit Opto.
  5. Shut off water and air.
  6. Check out with lab manager.