Research Initiation: In Situ Measurement of Transient Polymer Melt Temperatures via Infrared Pyrometry during Injection Molding

在加工过程中精确测量聚合物熔体温度通常是一个有问题的过程。这对于注射成型工艺来说尤其如此，因为注塑过程的循环和瞬态特性会导致聚合物熔体流温度的时空变化。目前在典型制造操作中测量聚合物熔体温度的技术要么被忽视，要么被滥用，要么非常缺乏，并且非常需要提高测量重要流变量（如聚合物熔体温度）的技术。本研究的主要目的是开发一种可靠的方法，用于在塑料制品制造过程中应用红外高温计测量聚合物熔体温度，从而使这种测量可以用于监测或控制目的。与传统的测温技术相比，红外高温计的几个主要优势是：响应时间在毫秒级，现场实时测量的能力，以及以非侵入式方式测量地下温度的潜力。然而，将聚合物熔体发出的红外辐射转换成不仅仅是半定量的信息并不是一个简单的过程。商用仪器将安装在注塑机上，以便研究人员可以收集和分析从一系列受控实验中获得的数据。这项研究的直接好处将是正确使用红外高温计的方法。

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.