Barrel zone temperatures

Figure 5.15 Outside barrel zone temperature measurements for a solids oonveying experiment using HIPS resin and a sorew speed of 50 rpm and a disoharge pressure of 1 MPa...

Figure 12.14 Screw speed, extrudate temperature, and barrel zone temperatures for a large-diameter extruder running stably and unstably...

Figure 12.22 Barrel zone temperatures for stable ABS resin extrusion...

A portable electronic data acquisition system was transported to the plant site and connected to the extruder panel. All available instrument outputs from the panel were connected in parallel with the acquisition system. Data collected included barrel zone temperatures, screw speed, motor current, pressure at the entry to the pump, transfer line temperature, and gear pump temperature. Process data were collected at a frequency of once every five seconds. 

Melt too hot] screw speed too high/exit barrel zone temperatures too high/de-gree of fill too low/[shear intensity too high] /heat zone temperatures set too high/[screw tip pressure too high]. ... 

Figure A.5 The melt temperature (376 °F) is shown here overriding the barrel zone temperature...

Loss of control of the product temperature can occur in cases of freezeout that occur over a large length of the barrel. Of course, as the layer becomes thicker, the loss of control becomes more severe. Product temperature may even increase as barrel zone temperature decreases. In extreme cases, the layer can be so thick that it is freed from the barrel walls by the flight and exits the extruder as solid particles in the melt stream. 

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