Papers by Author: Chun Hui Liu

Abstract: This paper analyzed several important issues in theory of non-plug flow solid conveying, which is about the extrusion molding process of the single screw extruder, they are mainly: compressive stress on the front and rear ends of the surface, and ; an increase trend of compressive stress , ; pressure in feeding compression section of the screw, .

Abstract: This paper analyzed granule of non-plug flow solid conveying section, and found the theoretical basis of the calculation model of granule from soil mechanics, and derived the constitutive equation of granule in detail, etc. All this work expounds the main idea of non-plug solid conveying theory from one side, so as to get a glimpse of the theory.

Abstract: While extrusion molding with single-screw extruder, extrusion pressure comes into being from feeding section; it is one of the basic conditions to ensure that extrusion process can be carried on normally, in order to ensure molding process goes smoothly, it must meet the following requirement: extrusion pressure generated during the process must be sufficient. Therefore it has certain engineering significance to design structure of a single screw correctly that a mathematical model for formation of extrusion pressure during single-screw extrusion molding will have to be established. This paper conducted a research on theory of extrusion pressure when powder of pure UHMWPE resin is still in feeding section by molding in barrel of the single screw extruder specially designed for pure UHMWPE, and established a n-lamina model of powder materials or grain materials which is in feeding section and at the state of non-plug flow solid conveying, and it provided a method to calculate extrusion pressure of the n-lamina model, thus it enriched and perfected theory of single-screw extrusion molding.

Abstract: Ultra High Molecular Weight Polyethylene(UHMW-PE) pipe is a kind of pipe of thermoplastic engineering plastic with excellent comprehensive performance, but the difficulty in molding is a technical bottleneck which has already affected the extensive application of pipe of pure UHMW-PE. Molding in barrel on the Single screw extruder is a new technology of extrusion molding method, which can continuously carry out pipe of pure UHMW-PE, the most significant advantages of the technology are as follows: under the circumstances of no need to feed any additives in the whole forming process, it can continuously carry out pipe of pure UHMW-PE, and the extrusion molding speed of it is up to 12 m/h above. During the process of it based on molding in barrel technology, one of the main factors influencing to whether UHMW-PE pipe can be successfully molded or not is whether the melting process of raw material is adequate and appropriate or not. This article will elaborate melting characteristics of raw material of UHMW-PE, establishment of mathematical model of melting process, and numerical simulation of melting process, which belong to the forming process of molding in barrel, and will provide a theoretical basis for correctly designing the structure of single screw extruder and temperature control system of single-screw extruder, based on Molding in Barrel Technology.