Extrusion Simulation And Structure Optimization Of ABS Coat Hanger Die

The coat hanger die was widely used in extrusion of plate,sheet and strip.The design of the coat hanger die was mainly concerned with the pressure drop and the uniformity of the velocity at the outlet.At present,domestic design of the coat hanger die mainly depends on surveying and design experience.Repeated repair and modification of the die cause that the cost of the design and manufacturing becomes high.The simulation design method is of great significance in the improvement of die design.Firstly,according to the theoretical design formula of coat-hanger die,a new coat-hanger die were designed.Polyflow was used for numerical simulation of the runner to verify The rationality of numerical simulation.The failure analysis of the concrete failure hanger die was carried out and excessive pressure drop was the main reason for the failure of the die head.Secondly,aiming at the invalid coat-hanger die,the effects of temperature,inlet flow rate and boundary slip coefficient have on the pressure drop and the uniformity of velocity were studied by numerical simulation and capillary rheology test of ABS.The process parameters especially the temperature,have a great influence on the normal extrusion of the coat-hanger die.Finally,these effects the radius R of the manifold and the height H of the sector have on the pressure drop and velocity field were studied.By means of orthogonal improvement,the optimal geometric size of the coat-hanger die was found.Pressure distribution and velocity distribution in the runner of the double coat-hanger die was studied by the Polyflow.Under the same process parameters,compared with the traditional coat hanger die,the double coat-hanger die had lower pressure drop and better velocity distribution.According to the simulations of the key parameters of failure die,the influence these key parameters have on the flow field were found which can provide a reference for the design of similar coat hanger dies.