In this paper, the influence of filler shape on foaming structures was investigated, using a batch method to penetrate supercritical fluid CO2 into an ABS polymer matrix. ABS was mixed with several types of fillers, and processed by a hot press method. VGCF (vapor grown carbon fiber, diameter of 150nm), calcium carbonate (particle size of 1.8μm) and glass fiber (fiber diameter of 10μm) were used as fillers.
By adding VGCF, the average diameter of the foam cell decreased and the cell density increased compared with those in pure ABS resin. On the other hand, with the incorporation of calcium carbonate or glass fiber, the diameter increased and density decreased. In a sample with small fiber and particle diameters, the foam cell average diameter decreased and the cell density increased.