The accurate and precise measurement of polymer melt temperatures during processing is generally a problematic procedure. This is especially true for the injection molding process where the cyclic and transient nature of the operation results in spatial and temporal variations of the polymer melt stream temperature. Current techniques to measure polymer melt temperatures in a typical manufacturing operation are either ignored, misused, or highly deficient, and there is a great need to advance the technology of measuring important stream variables such as the temperature of a polymer melt. The primary objective of this study is to develop a reliable methodology for applying infrared pyrometers to the measurement of polymer melt temperatures during the manufacture of plastic articles, whereby such a measurement could then be used for either monitoring or control purposes. Several key advantages that infrared pyrometers have over conventional thermometry techniques are: response times on the order of milliseconds, capacity of in situ real-time measurement, and potential for measuring subsurface temperatures in a non-intrusive fashion. However, the conversion of infrared radiation emitted from a polymer melt into more than just semi-quantitative information is not a straightforward procedure. Commercially available instrumentation will be installed on an injection molding machine so that the researchers can collect and analyze data obtained from a series of controlled experiments. An immediate benefit from the research will be a correct methodology for using infrared pyrometers.
