Recycled plastics are considered to have less mechanical and durability properties. Usually, the reason of above phenomena was thought to be caused by chemical degradation. However, we recently found that pre-consumer recycled polypropylene was not chemically degraded and had almost same molecular properties of virgin polypropylene. But the inner structure and mechanical properties were very different. From the analysis of differential scanning calorimetry and small angle X-ray scattering measurement, we concluded that number of the adhesion sustaining molecules that connecting between grains of polypropylene cause the mechanical difference. This result suggests that if we can increase the number of the adhesion sustaining molecules, we can improve the mechanical and durability properties of recycled polypropylene. In this study, we compared the mechanical properties and inner structures of virgin polypropylene (VPP) to those of pre-consumer recycled polypropylene (Pre-RPP) in various hot press molding conditions. From the results of these experiments, we found that mechanical properties of Pre-RPP depends on hot pressing and cooling conditions of making these films. From small angle X-ray scattering, some correlation was found between mechanical properties and inner structure.