Design Of Extrusion Mould For Polymer Five-lumen Micro Tube Based On Flowing Balance

At present, the micro/nano science and technology has made significant progress, the products also become small and lightweight. The traditional plastic extrusion technology has a very important branch—micro extrusion technology. The products of micro extrusion have many applications, such as plastic optical fiber, interventional catheter, automotive micro tube etc. Plastic micro tubes have many excellent advantages in physical properties, chemical properties, mechanical properties and processing performance. Therefore, in this paper, the design of extrusion mould for polymer five-lumen micro tube based on flowing balance was studied. It has very important practical significance and broad application value.In the paper, the design product is a plastic five-lumen micro tube. Its cross section is very small, and has complicated lumen. So the design and manufacturing of extrusion mould, and the processing of polymer melts play a significant role. The material of tube is polypropylene. Firstly, the initial structure parameters of extrusion mould was designed and calculated based on the design theory and equations of extrusion technology. On this basis, combined with the size and location of the micro tube cross-sectional size shape, cavity, considering the die-swell effect, the cross section of mould exit was designed. It is the important base of the following flow analysis.Then, the flowing process of polymer melts in extrusion mould of five-lumen micro tube is taken as the research object, using3-D modeling software PRO/E and finite element analysis software ANSYS, and the orthogonal experiment analysis method, channel structure parameters were studied (compression angle, eccentricity, mould mandrel clearance). Their effects on the flow uniformity of polymer melt at the mould exit were studied. Based on the results of flow analysis and the theory of flow balance, channel structural parameters of extrusion mould were determined.Finally, based on the channel structure parameters, structure design of the whole extrusion mould and all the components were designed in detail. The strength and stiffness of components were considered. At the same time, no leakage and convenient assembly and disassembly were ensured. The extrusion mould of micro tube was fabricated by the precision machining technology and micro EDM technology. On this basis, five-lumen micro tube was extruded; the satisfied micro tube was gained. So the design method of extrusion mould for polymer five-lumen micro tube based on flowing balance was verified.