Rheological properties of foam plastic melt
DATE：2021/8/30 8:29:34 / READ： / SOURCE：This station
Rheological properties of foam plastic melt
Rheology is a science that studies the deformation and flow of materials. It covers a wide range of fields, covering almost all materials and their processing and shaping. The rheological model expresses the dynamic properties of the material and expresses the functional relationship between the stress, strain and time of the material. In this way, the processing performance and use performance of the material can be understood, which provides a theoretical basis for formulating, improving and controlling processing technology and methods. The rheology of polymer processing is the theoretical basis of plastic processing and also the theoretical basis of plastic foam molding. The rheological behavior of plastics is related to the structural properties and conditions of plastics.
The structural properties of plastics include the molecular structure of the polymer, the aggregation state of the polymer molecules, the molecular weight and molecular weight distribution, the type and amount of various additives, and so on. The conditions such as temperature, pressure, time, shear, stretching, vibration, etc. Past research focused on the effects of temperature, pressure, and time. The dynamic effects of shear, stretching, and vibration are rarely studied. The dynamic effects are critical to the foam molding process, especially the nucleation process. Directly affect the generation, conversion and distribution of energy in the melt. It is an important basis for controlling the foaming process.
We study the rheological behavior of plastic melt in order to better choose the molding program, formulate the raw material formula, molding process and equipment, etc., and propose the theoretical basis for the optimization program. The rheological behavior of plastic melt containing foaming agent is significantly different from that of plastic melt without foaming agent. Therefore, to process foamed plastics, it is not enough to only understand the rheological properties of the plastic melt. It is necessary to understand the rheological properties of the plastic melt containing the foaming agent and its influencing factors.
In the plastic foam molding process, the viscosity and elasticity of the plastic melt are two basic and very important rheological parameters. This chapter will focus on the factors that affect the viscosity and elasticity of the plastic melt containing the foaming agent. Their impact on the foam molding process. This is an important theoretical basis for formulating raw materials, molding processes and equipment.
Author：admin