Solving Extrusion Instabilities

There are many different causes of extrusion instabilities. Even though the mechanism of the instability is not always clear, the following measures often reduce extrusion instabilities  

The first approach to the problem is generally adjustment of the temperature profile or other process conditions. If temperature adjustment does not solve the problem, one should check the hardware thermocouples, controllers, screw, barrel, drive, etc. If the problem is not associated with the hardware, it must be a functional problem and one should determine what functional zone is causing the problem. The troubleshooting flow chart in Fig. 11.34 can help in systematically exploring the possible causes of the instability. 

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