Abstract

The specific volume (v) of plastics establishes a controllable relationship between material, process and product, and it is the key to improving the molding accuracy and production efficiency of injection molding. The specific volume is not only dependent on the pressure (p) and temperature (T) but also on the variation rate of pressure and temperature, which is defined as the process dependence of specific volume of plastics. The digitalization of pvT behavior of plastics for precision or intelligent injection molding is important. The pvT behavior of plastics has a strong process dependence, and process parameters such as cooling/heating rate, compression/decompression rate, and initial temperature/ pressure have different effects. It is important to accurately measure the pvT data and establish a highprecision prediction model, and then the precision and intelligent injection molding process control can be realized. This mini-review presents the research progress on measurement, modeling, and control of process-dependent pvT behavior of plastics for injection molding. The challenges and perspectives for future research on the specific volume of plastics are discussed.

Keywords: Specific volume; Process dependence; Pressure; Temperature; Plastics; Injection mold