Experiment
The experimental parts of this study were published in our previous
paper on the measurements of the degree of fill27. The
materials and apparatus were the same as those used in that study. The
measurements of the pressure and temperature of the resin are explained
in detail below.
Materials
Homo polypropylene (F-704NP) was supplied by Prime Polymer (Japan). The
melt flow rate was 7.0 g/10 min, as measured according to the ISO
1133:97 standard (catalog value). The oscillation shear viscosity
(complex viscosity) was measured using a modular compact rheometer (MCR
302-WESP, Anton-Paar, Austria) with a diameter of 25 mm and a 1-mm-thick
parallel plate fixture. The oscillation range was 0.03 to 100 rad/s. The
strain was 1.0%. The temperature control units were a P-PTD200 and an
H-PTD200. The temperatures used were 180, 190, and 200 °C. Based on the
Cox–Merz rule for a linear polymer, the complex viscosity was used to
obtain the parameters for the Cross model described by Eqs. (30) and
(31), as listed in Table 1. The complex viscosity data and associated
curves of the Cross model are shown in Figure 3.