Research On Extrusion Process Of Polypropylene Micro-tube With Rectangular Channer

Rectangular channel microtubules has flat channel shape,parallel channel wall and large specific surface area,which is often used in microfluidic,biological or chemical detection,microheat transfer and other fields.However,the existing extrusion molding technology is difficult to meet the requirements of uniform wall thickness and high shape precision of rectangular channel due to the phenomena of extrusion swelling and melt rupture.Therefore,it is necessary to explore the extrusion molding of rectangular channel microtubules.Rectangular channel based on extrusion forming polypropylene tubes as the research object,based on developed numerical simulation of rectangular channel micro tube extrusion,and then explore the extrusion molding process on the quality of the micro tube forming,and to achieve expected cross section shape of rectangular channel microtubules(rectangular section L×W=7mm×3 mm,rectangular channel microtubules length-width ratio R_c=2.74)as the goal,The main research work and results are as follows:(1)The extrusion head of rectangular channel microtubule was developed based on numerical simulation.According to the modern design theory of the extrusion and the extrusion structure design criterion to choose the nose flow channel structure parameters,using POLYFLOW software counterpart mode shape are numerically simulated,analysis of polypropylene extrusion swelling mechanism in the process of extrusion molding and extrusion process of the mouth of the extrusion swelling behavior of the extrusion die cross section shape of reverse design,An extruder head for rectangular channel microtubules was developed.(2)Based on numerical simulation,the influence of process parameters on rectangular channel microtubule forming was explored.POLYFLOW software was used to study the influence of technological parameters(inlet flow rate,gas injection pressure)on the extrusion expansion of polypropylene rectangular channel microtube during extrusion,and the influence of different technological parameters(inlet flow rate,gas injection pressure and traction speed)on the product section shape.The results show that the traction speed has a great influence on the length to width ratio of microtubules in rectangular channels.(3)The influence of process parameters on rectangular channel microtubule forming was investigated experimentally.Structures,experimental platform,the process parameters through single factor experiment research(inlet flow rate,gas injection pressure and traction speed)on the influence law of rectangular channel microtubules products section size,verifies the correctness of the results of numerical simulation,and based on rectangular channel aspect ratio of the orthogonal experiment,based on the analysis of poor get in the nose when the temperature is 200℃,The optimal process parameters of rectangular channel microtubule forming are as follows:Q_p=180.12mm3/s,P=10Pa,v_n=25mm/s.In this paper,the feasibility of producing rectangular channel microtubules by extrusion molding is explored,which provides guidance for the parameter setting of the actual production of rectangular channel microtubules.