- Dr. Kun Gao from Brightlands Materials Center (BMC) shared their study of the interfacial adhesion in between injection-molded and over-molded processes. The crystallization and temperature dominate the interfacial strength in over-molding process, and various crystalline morphologies can be formed, such as spherulite and shish-kebabs.
- For PP, various crystalline phases can appear, including α, β, γ-phase, and mesomorphic (high cooling rate)
- The result showed that over-molded samples are weaker than the injection-molded ones, and 70°C samples are stronger than 40°C. It is important to ensure a reliable prediction of the thermal history (Temperature, Pressure). Moreover, the shear stress is also an important factor that should be considered.