Injection molding is one of the important industrial fabrication techniques for polymeric materials to produce thin products. It produces products with complex three-dimensional polymeric parts. Injection molding of thermoplastics involves injecting molten resin into a mold at high pressure and ejecting the cooled part. A better understanding of the friction conditions during the molding process can lead to improved injection mold and part designs .
Therefore, injection molding is a process with 
• high-pressure squeezing of complex and compressible hot melt polymer fluid,
• hot melt that flows through a very small gate into a cold cavity mold with high velocity,
• end product having an apparent ...