Abstract:
The experimental study was conducted on the effects of compounding conditions in the open mill and storage time of resulting rubber compound before extrusion on the properties of resulting rubber compound, such as initial mooney viscosity, minimum mooney viscosity, scorch time (T5) and T35, and on the properties of rubber foam product, such as, die swell, thickness, inner diameter, expansion, and density. The compounding were performed at 76, 78, 80, 82, and 84ํC and the resulting rubber compound were stored for 0, 2, 4, 6, 8, 10 and 12 hours. The results showed that, at any storage time, when the mixing temperature in the open mill was increased, the initial and minimum mooney viscosities were increased, and the T5 and T35 were decreased. At any mixing temperature, when the storage time was longer, the initial and minimum mooney viscosity were increased, and the T5 and T35 were decreased. However, the effects of mixing temperature and storage time on the properties of rubber foam products could not be clearly evaluated from the experimental data. Besides, it was found that when the value of initial mooney viscosity of the resulting rubber compound was higher, the thickness and inner diameter of rubber foam products had the tendency to increase. But when the value of T5 was higher, the thickness and inner diameter of rubber foam products had the tendency to decrease. The least square regression analysis method showed that the above relationships had the tendency to be linear.