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

在加工过程中准确和精确地测量聚合物熔体温度通常是一个有问题的过程。对于注塑成型过程尤其如此，其中操作的周期性和瞬变性质导致聚合物熔体流动温度的空间和时间变化。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、误用，要么严重不足，迫切需要改进测量重要流动变量的技术，如聚合物熔体的温度。这项研究的主要目标是开发一种可靠的方法，将红外高温计应用于塑料制品制造过程中聚合物熔体温度的测量，从而可以将这种测量用于监测或控制目的。与传统测温技术相比，红外高温计的几个关键优势是：响应时间在毫秒量级，能够进行现场实时测量，并且有可能以非侵入性的方式测量地下温度。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。商业上可用的仪器将安装在注塑机上，这样研究人员就可以收集和分析从一系列对照实验中获得的数据。这项研究的直接好处将是使用红外高温计的正确方法。

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.