Plastic Profile Extrusion Die Cad System Key Technologies

Plastic materials for construction are the new kind of building materials. Plastic profile has vast vistas, which is a primary kind of plastic materials for construction. The extrusion die for plastic profile is the key equipment of its production, and has a great effect on the quality and the production circle. It is very important to study the CAD system for extrusion die in order to enhance the level and efficiency of designing and manufacturing.The paper starts with analyzing developing trends of the plastic profile extrusion die, and aims at single hollow profile.The key technologies of the extrusion die CAD system are discussed, and the SunnyCAD system is built.Firstly, based on the analysis of the design principle, the software engineering ideas are applied to ensure the advanced, mature, economics quality, and then the frame of the CAD system is established.Oracle serves as background in order to build an excellent engineering database. The database is established after collecting and classifying and analyzing the data which is produced during die manufacturing and repairing. The corresponding repairing countermeasures are given after analyzing the common failures of plastic profile.Inner ribs are thin-wall spacers, forming closed cellular structure to increase the stiffness of extruded profile. Rules to determine the clearance of die cavity, the length of flat portion of flow passage, and the way of supplying material to the inner ribs are formulated to guide the design of extrusion die. The non-formalized experience about the choice of the way of supplying material to the inner ribs is abstracted and rule-based reasoning method is used to enable the system to search and output the way.As software extrusion flow process is immature, the paper introduces a audacious method to use the flowing analysis software of injection mould to simulate extrusion flow process. It is proved that the theoretic feasibility based on the hydrodynamics and the constitutive equations, then the applied example is given to testify the practical feasibility of the assume. But the method needs the manufacturing evidence.Lastly, after analyzing the way of hot exchange, the FEM analysis on the cooling process is done by the ANSYS software in order to master the transient temperature field of the cooling process. The simulation results show that the temperature drop of the main-walls is great, the temperature drop of the inner-ribs is small, and the temperature drop of the functional block is middle. It will make great effect on the designing of the calibrating tool.