Filling behavior of micro-array structure product of iPP was investigated by numerical analysis and injection molding experiments.An injection mold was designed to produce products with micro-cylinder structure 500 μm in diameter.The filling process of flow front of micro-cylinders of numerical simulation and injection molding experiment was relatively consistent in the general trend.However

formation of flow front and varying patterns of the height of micro-cylinder in the filling process in the numerical simulation deviated from the experiment.Injection molding experiment showed that micro-cylinder mold wall

melt flow rate

and melt flow inertia played an important role in the formation of flow front.Early filling contributed little to the micro-cylinder molding.Turbulence appeared on the melt flow directly below the micro-cylinder.The flow front was like the shape of acentric ellipsoid crown and gradually developed into the shape of spherical crown.