Study On Buckle Winding Technology And Mechanism Of UHMWPE Pipe

As a common pipe,plastic pipe has the advantages of light weight,recyclability and long life compared with traditional metal pipe.Large diameter plastic pipe is widely used in drainage engineering,sewage engineering,rescue and escape and other fields.Ultra high molecular weight polyethylene(UHMWPE)is widely used as a high-performance plastic in recent years.Millions of molecular weight make its molecular chain entangled seriously,resulting in extremely poor melt fluidity.It is difficult to process UHMWPE products by traditional methods,which limits the application scope of UHMWPE.At present,the forming methods of large-diameter plastic pipe mainly include extrusion and winding.The extrusion of large-diameter pipe has some disadvantages,such as complex die,prone to sag and so on.The winding of large-diameter pipe has some disadvantages,such as difficult continuous forming,complex forming process and so on.In this paper,a new technology of large diameter UHMWPE pipe buckle winding forming is proposed for the first time,and a new device of UHMWPE pipe buckle winding forming is successfully developed,which breaks the existing technical barriers of large diameter UHMWPE pipe forming;the eccentric rotor extruder is used to successfully realize the stable and continuous extrusion forming of UHMWPE profile blank,and the large diameter UHMWPE is continuously formed by the way of buckle overlapping UHMWPE large diameter pipe with diameter of 400 mm and wall thickness of 15 mm was successfully prepared.In this paper,the mechanism of pipe buckle winding forming is analyzed.On the basis of reasonable assumptions,the physical and mathematical model of buckle winding forming process is established.The influence of key process parameters on the pressure distribution,velocity distribution and temperature distribution of the melt in the buckle winding forming process is revealed theoretically for the first time,which provides theoretical basis and guidance for practical production.The results show that:increasing the rotor speed can increase the volume flow of billet,thus increasing the melt pressure at the buckle;the circumferential velocity of melt at the buckle increases with the increase of rotor speed;the increase of rotor speed can increase the temperature of bonding surface when the melt is buckled.By adjusting and controlling the plasticizing temperature,rotational speed and core membrane module rotational speed of eccentric rotor extruder,the forming process of buckled winding pipeline was explored.The mechanical properties,thermal properties and bonding effect of buckled winding pipeline were analyzed.It was found that the mechanical properties and thermal properties of buckled winding UHMWPE pipeline changed with the plasticizing temperature and rotational speed of eccentric rotor When the plasticizing temperature is 200-230-245-245-235-225?,the eccentric rotor speed is 15 rpm,and the core film speed is 1.2rpm,the UHMWPE pipe has the best mechanical properties,crystallinity,thermal stability and good bonding effect of the buckle bonding surface,and its ring stiffness and impact strength are 4.38 KN/m~2 and 74.26 KJ/m~2 respectively.The experimental results match with the theoretical calculation results,and the response mechanism between the process parameters and mechanical properties of large diameter UHMWPE pipe is established.The successful development of UHMWPE pipe buckle winding forming equipment has changed the traditional forming method of UHMWPE pipe,and successfully realized the buckle winding forming method of large diameter UHMWPE pipe,which provides a new solution for the preparation of high-performance UHMWPE large diameter pipe used for escape pipeline and conveying abrasive and corrosive media,and will promote the forming technology of large diameter plastic pipe.It is of great engineering and economic significance to further develop and apply the technology and equipment.