Troubleshooting - Extrusion

Extrusion processing conditions vary depending on the ABS grade and application vendor bulletins should be consulted for details. Information for assistance in troubleshooting extrusion problems can be found in reference 141. 

The final component we need to consider is the instrumentation and control system (Figure 14-10). Good instrumentation is vital to ensure that an extrusion line is operating efficiently and to troubleshoot extrusion problems. Because we cannot see inside the extruder, nor would we leam much even if we could, instrumentation serves as a window onto the process. Monitoring an extrusion system has been compared to monitoring a patient in the hospital you always need to measure vital signs, like blood pressure and body temperature. Likewise, an extrusion line that is not properly monitored can... 

The purpose of the instrumentation and control system (Fig. 2.14) is to measure and control important processing parameters. Without the data provided by this system, it would be very difficult to maintain a safe and efficient process and to troubleshoot extrusion problems. The data provides a window to the process, since we cannot see inside the extruder (and probably would not find it very useful if we could). Monitoring an extrusion line has been likened to monitoring a patient in a hospital we certainly want to measure the patient s vital signs, such as body temperature and blood pressure. Similarly, we need to monitor extrusion parameters, so the system does not become unstable, leading to a dangerous situation or to the production of costly scrap. 

The book Troubleshooting the Extrusion Process-A Systematic Approach to Solving Plastic Extrusion Problems [59] by del Pilar Noriega and Rauwendaal was the first book devoted exclusively to troubleshooting extrusion problems. A second edition of this book was published in 2010. 

The remaining Chapters 9 through 15 are devoted to different types of extrusion troubleshooting analyses. These chapters include presentations on scale-up tech-... 

This section introduces simple polymer reaction chemistry used to produce many commodity polymers. Understanding this simplified approach to the chemistry of polymer production Is Important In troubleshooting many extrusion processes, especially those that are producing unwanted degradation products that contaminate the discharge resin. There are two general types of polymer production processes 1) step or condensation reactions, and 2) addition or vinyl polymerization reactions. An overview of the reaction mechanisms wifi be presented in the next sections. 

Often troubleshooting guides are provided by equipment manufacturers for common problems. These guides are helpful for many of the simpler problems associated with the equipment. Some resin manufacturers are an excellent resource for troubleshooting processing problems that are specific to a resin. Subject matter experts or extrusion consultants are also resources for troubleshooting an extrusion process. 

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