The Effect of Nitrogen Bubbles on Microstructure of Natural Rubber Foams Produced by Bubbling Process

Natural rubber latex foam (NRF) was produced using nitrogen bubbling process. The process involved flowing of nitrogen with a constant flow rate of 80 cc/min through a bubble column, filled with latex compound, to generate a high bubble-volume inside the column. Microstructure of the finished product was examined using a scanning electron microscope (SEM), in comparison with that of the purchased Dunlop foam. The results showed characteristic of the as-produced foam that they composed of spherical pores with a uniform interconnected-cell structures. On the other hand, the Dunlop foam exhibited non-spherical pores and non-uniform cell structure with broken cells.