Experiment And Numerical Simulation Of The Extrusion Process For The Seal Profile Of Glass Fiber Reinforced PA66

Along with the expansion of application field and the increase in the productperformance requirements, cross-section shape of the plastic profile is developed preciselyand complicatedly. Also, the reinforced and filling plastic composites of which melt-flowproperty declines are gradually applied to the complicated cross-section plastic profiles. Asan important reinforced engineering plastic, glass fiber reinforced Polyamide (PA)66isused for the seal profile products. Because of high-crystallization, melt flow property ofglass fiber reinforced polyamide66near the melting point, influenced by temperature andshear rate, varies nonlinearly in the extrusion process and causes difficulty in the stableextrusion process of glass fiber reinforced polyamide66. Therefore, study on the extrusionflow property of glass fiber reinforced polyamide66is adapted to extrusion die design,computer numerical simulation of extrusion process and extrusion process design, in orderto mold the continuous plastic seal profile with good shape and size, which has importanttheoretical and practical meanings for the successful application of glass fiber reinforcedpolyamide66in the extrusion process.Firstly, the rheological property of glass fiber reinforced polyamide66is studied viasingle-screw extrusion cappilary rheometer to analyze the main factors affecting the meltviscosity in the extrusion process, and the rheological laws can be found. On that base,constitutive equation used for the rheological property of glass fiber reinforced polyamide66is found, while the values of rheological parameters are calculated exactly. The resultsand conclusions have important guidings to the extrusion die design, numerical simulationof the extrusion process and extrusion conditions design for the seal profile.Secondly, Based on the rheological studies and results, through the finite elementnumerical simulation application ANSYS, simulation and analysis of the melt3-dimensional flowing process in the extrusion die of seal profile are carried on, and theextrusion flow laws are found. A method to evaluate the melt flowing balance of glass fiber reinforced polyamide66in the extrusion die of seal profile is proposed to analyze theinfluence of screw speed and melt temperature on the flowing balance at the outlet ofextrusion die. Increasing the screw speed is bad for the uniformity of melt flowing velocityat the outlet of die, while improving the melt temperature makes it well.Finally, Based on the numerical simulation results, through the variable factors ofextrusion process conditions including screw speed, the machine carrel temperature and theextrusion die temperature, extrusion process experiment is carried on to mold the glassfiber reinforced polyamide66seal profile product with good cross-section shape and stablesize. The relationships and laws between the variable conditins of extrusion process, themelt flowing balance in the extrusion die and the final quality of seal profile product arefound, and some practicable improvements are proposed in the experiment. The resultsshow that under the conditions of low screw speed (5r/min) and temperature near themelt-point, it is successful to mold glass fiber reinforced PA66seal profile product ofintegrate section-shape and stable size by extrusion process.