latex and blend gelled at a pH of approximately 8.5. The gelling times for the NRL latex mix and the blend mix were at 5 min and 2.5 min respectively. The faster rate of gelling in the blend is due to the higher loading of SSF in the blend.
It is common for foam to shrink during washing and drying due to the removal of water. The shrinkage of the foam samples in this study is shown in Figure 2. It is noted that shrinkage is an important characteristic in latex foam technology as it determines the size of the finished foam product.
In estimating the magnitude of shrinkage, it is important that diverse variables such as the water content of the latex compound and the speed of gelation are adequately controlled. The higher volume of shrinkage of the blend foam seen in this study can be attributed to the greater initial proportion of water in the blend