Experimental study and simulation of interface development and penetration in two-component transfer molding of rubber compounds

Simulation and experimental studies of pressure-controlled sequential transfer molding of two SBR rubber compounds under isothermal condition have been carried out to obtain a two-layered sandwich structure. One SBR compound, intended for the skin, is first laid up in the cavity; and another SBR compound, intended for the core, is used for transfer. The SBR is subjected to pressure in order to penetrate into the skin and push the layup to fully fill the cavity. The obtained moldings have an encapsulated skin/core sandwich structure. Two material combinations with different viscosity ratios have been studied. The rheological interaction of skin/core components and its effect on the penetration behavior and interface shape have been investigated. The influence of processing conditions, such as the volume fraction transferred and pressure, is elucidated. From the experiment and simulation it is found that the penetration and the interface development are significantly affected by the rheological properties of the compounds and the volume fraction transferred. At the same time, the pressure imposed during transfer molding is found to have little effect on the interface development ut a constant volume fraction transferred.