Flowing Channel Structure Of Coat-hanger Foamed Sheet Die And Research Of Foaming Theory

With the growing national economy,the application of foam sheet become wider one each day. Many studies have shown that the foam is closely related to the quality of products and the rate of melt. After reviewing many polypropylene foam theories and substantial information,this thesis concluded nose design flow channel impact a great effect on the foam. However,in China,convection current design research is still relatively insufficient. Therefore the study on designing with foam nose higher polypropylene foam sheet has a positive and practical significance,especially as the hanger-type foam die plate flow channel has been highlighted a lot in today's research.This thesis analyzes the influence imposed by viscoelastic melt,blowing agent solubility and diffusion coefficient,screw speed,pressure distribution along the way, the temperature ratio upon.For particular materials and certain experimental conditions,the pressure along the foaming magnification is of the most significance among all the factors. By using FLUENT analysis software,this thesis conducts analysis on hanger-style flow of different structural parameters under the three fluid analysis to obtain suitable structural parameters of the flow channel. By analyzing convection Road through the different path pressure drop,this thesis comes to the result adjustable damping zone of the flow channel's location.In order to be able to adjust the pressure drop along the way conveniently,the paper offers a regulatory structural design on flow to the entire head,accompanied with the design of the damping rod and conditioning,by regulating the melt flow channel at the flow rate to eventually regulate the pressure. And through ANSYS software to study the material of damping properties,rod damping adjustment rod limit is derived,as well as the reasonability of the design and regulation. In this thesis,the experimental materials used are polypropylene PP,which has many advantages. Based on the analysis above,by adjusting the pressure of damping zone,namely,adjusting the damping rod adjustment device so that to make the export rate almost simultaneously to observe the different export rate,as well as the uniformity of foam. Analysis of melt extrusion foam pore structure and stability of uniformity help me verify the reasonability of design and theoretical analysis.The coater-hanger foamed sheet die is one of very important part of polymer extruding equipment, and the quality of die channel influence production foaming magnification and extruding uniformity directly ,so as to further influence production quality. The study of channel structure design and foaming theory in this thesis has some practical significance to quality going up of products with wide and flat shape.