Effect of the CO2 on Viscosity Change in Continuous Microcellular Foaming Processing
Yongrak Moon, Sung Cha
Yonsei Univ., A109, Enginering Hall, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul
South Korea

Keywords: Microcellular Foaming Process, Viscosity Change, Rheology

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Now we have many studies to develop continuous process that improves various mechanical properties in the method of making polymer resin have many micro bubbles.
In the way above, the auto industry gives many tries to meet both purpose, the fuel efficiency improvement and the high impact absorption.
To apply this to industries, continuous polymer processing method should be developed.
The two models of polymer processing methods are injection modeling and extrusion.
Understanding rheology is essential to design mold or die, and it is so important to control the condition of process. Also, this data is got the utmost out of simulation carrying out.
In this paper, we will see the measurement of rheology in one phase that mixed polypropylene which contains talc with carbon dioxide of super critical fluid state, and will compare its result with the simulation result.
The polymer that is used in automobile’s interior material will be used in the test, its talc content is 5, 10, 20% in pure PP and no talc pure PP.
CO2 will be supplied with supercritical state condition, and 2,4,10ml/min of it that is given to the barrel by using syringe pump, will be mixed with test polymer.
We will carry out the test by using 10mm L/D=32, BRABENDER extruder and 30mm L/D=34 extruder, and nozzles which size are 2,3,4mm.
We will see the viscosity & shear rate change, occurred in the condition of talc content & CO2 quantity variation. We also carry out simulation using MOLDFLOW software with this result.
Our goal is to get the simulation result from gas supplying polymer and none gas supplying polymer, and finally show the guide line of mold and die design that is applied to microcellular foaming process method.