Experimental Research And Forecasted System Development Of Die Swell Ratio Of Polymer

The design of die became complicated when the phenomenon of die swell about polymer came forth in the extruding process.Moreover,it wasted a lot of manpower and material resources that the process carried through from debugging die to refinishing die.In order to avoid the mistake in the process of design and guarantee the forming and quality of product , it is necessary to study the phenomenon of die swell for polymer.Therefore the rheology of polymer is all the while a research hotspot of in this domain.But there was a lot of biggish localization between the theory and the formula in this aspect.And those theories which every scholar brought forward were not unanimous each other.Furthermore,there was deviation between the theoretical value calculated by theory formula of die swell and the measured value.So it is necessary to study the phenomenon of polymer by the experiment which is similar to the actual process condition.In this work, the capillary rheometer was used to test the die swell ratio on three kinds of material, including of PS (polystyrene),ABS (acrylonitrile-butadiene-styrene) and HDPE (high-density polyethylene).In order to investigate the effect law of different factors on the die swell,this subject introduced dies with different inlet angle with different length to diameter ratio to do the extrusion experiment.The result showed that the die swell ratio augmented with the increase of shear stress and shear rate on the three kinds of material.The phenomenon of die swell was more obvious when the length of diameter ratio was smaller.When the length to diameter ratio was greater than 10,however, the variation range of die swell ratio became smaller with the augmentation of length to diameter ratio.The die swell ratio got bigger with the increasing of the inlet angle in die.But the effect of inlet angle to die swell ratio was not very obvious in the range of used inlet angle in this paper.Based on the experiment research,the forecasted system was developed by the means of the hybrid programming which availed of VB programming language and Matlab programming language in this subject.The system could transport the technique of artificial neural network to application software system . It possessed of better man-machine interactive interface.Moreover the user could input the sample data and die parameters into the system to train the neural network,examine the train errors and forecast the die swell ratio conveniently and so on.The prediction effect of the software was satisfied after contrasted result of predicted value with the measured value.The error of prediction had reached the order of magnitude of 10-2.The prediction points tallied with the measured points very well.Therefore the software was a beneficial try for the transition of theory study of die swell to practice application. .