Troubleshooting injection molding process

Most composites are produced by extmsion or injection molding, therefore troubleshooting methods should be related to the processing method and reviewed using information in respective sections below. 

Angel, G., Injection Molding and Color A Basic Look at Design, Processing, and Troubleshooting, SPE ANTEC Tech. Papers, 48, 2508 (2002)... 

Several case studies are presented in the next sections that show some common root causes of contamination in injection-molded parts. In these case studies, the problem is presented in a manner that the troubleshooter would encounter during a trial or information-gathering session. In each case study, the modifications required to fix the process are detailed along with supporting fundamental information. Two of the case studies used (ET) screws to eliminate the defects. ET screws and other high-performance screws will be discussed in Chapter 14. 

Expert systems can also be used off-line as advisory systems. If some leeway is left in the process specifications, operators can even be instructed to make simple variations in the process. Hajicek developed an expert system for troubleshooting injection molding, which was designed to be used by operators to adjust controls as needed whenever part quality suffered [20], These expert systems do not necessarily plan an entire cycle. As we will see in the section on in-process control, however, they can be used to do so. There are even specifications that include rules for altering the cure cycle in response to the results of quality acceptance tests such as flow and volatiles, a primitive set of heuristics. 

Tables 3.6 and 3.7 show, respectively, injection molding conditions and a troubleshooting guide for various TPEs. However, one should contact the material supplier to obtain detailed information for the process.

Injection Molding Troubleshooting Guide, 4th ed.. Advanced Process Engineering. Cre-ateSpace PubUshing. 

The use of PES material requires that it be self processed for injection and extrusion molding, etc. The toowledge of the rheological behavior of PES over an industrially relevant range of shear rate and temperature is essential for proper material processability, process design optimization and troubleshooting. 

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