Summary

Plastic products are made by processing techniques such as extrusion or molding. For a satisfactory-quality polymer compound should flow in a desired manner in mold or from an extruder. Plastics exhibit very high viscosity as compared to normal solvents or monomers. The viscosity depends upon the processing conditions like temperature, pressure, and processing rate. A given polymer may show very different behaviour at different speeds of extruder or it may show different behaviour in equipment of different sizes. The plastic of similar MFI procured from two different suppliers can give poor quality product. Incorporation of recycled material can be problematic in some cases. Production of a master batch with different grades can give problems. All these may be connected to the flow properties of plastics. For product development, understanding of efficiency of stabilizers, thermal degradation, gel time, mixing time, etc. is important. These aspects are covered in applications. The masterbatch may show poor dispersion in one machine but may work satisfactorily in other machines. All these effects are related to flow properties. This course covers the basics of Flow Properties (viscosity behaviour), the measurement techniques, and applications of Flow Properties in understanding polymer processing or manufacturing in simple manner without complicated mathematical equations.