However, one could object that the structure developing under isothermal conditions is completely different from that forming in injection molded plates. Large shear stresses, changing temperature and pressure both with time and location in the part must result in completely different structure. In order to check the characteristics of structure forming under such conditions, the fracture surface of injection molded plates were etched and subjected to high resolution SEM study. Micrographs taken from the core of 2mm thick plates are presented in Fig. 10. The shin-core structure of the plates is not considered here, since we assume that the structure of the core determines optical properties. The difference in the texture of the polymer containing the three nucleating agents is clearly visible in the figure. The microcrystalline structure developing in the presence of the clarifier gives a very smooth appearance (Fig. 10a). The etched fracture surface of the plate containing the heterogeneous nucleating agents seem to be rougher (Fig. 10b); obviously the micro-spherulites formed are large than in the previous case. The very large quadrites created by PVCH nucleation can be clearly distinguished in the micrographs in Fig. 10c. The polymer contain only 2 ppm PVCH in this case, which is not comparable to the 2000 ppm of the other two nucleating agents. However the structure is much rougher even at 200ppm PVCH (not shown), only the quadrites cannot be distinguished so well as in Fig. 10c. We can still claim with certainly that the main characteristics of the structure and the relative order in the size of the main structural unitsis the same in the core of injection molded plates as in the simples obtained in isothermal crystallization experiments. Clear differences can be observed in the effect of the three nucleating agents studies, which may explain their dissimilar effect on properties.