METHOD FOR PREPARATION OF MICROCELLULAR FOAM WITH UNIFORM FOAMING RATIO AND EXTRUDING AND FOAMING SYSTEM FOR THE SAME

摘要

Disclosed herein is a method for preparing a microcellular foam, including mixing a thermoplastic polymer resin plasticized in an extruder with a foaming agent, melting the mixture and forming micro pores in the melted mixture while passing the mixture through a pressure drop zone of an extrusion die, and cooling the melted mixture formed with the micro pores while passing the melted mixture through a cooling zone of the extrusion die, and a system capable of carrying out the method, further including setting the temperature at a downstream end of the pressure drop zone and the temperature at an upstream end of the cooling zone such that there is a temperature difference of 30 to 2000C between the temperatures, to extrude the mixture in the form of a microcellular foam, and pultruding the microcellular foam emerging from the extrusion die at a predetermined foam induction ratio by a pultrusion unit, to finely control the foaming ratio and time-dependent physical properties of the microcellular foam.