Supercritical fluid micro-foaming screw rod mixing device and method

Abstract

The invention discloses a supercritical fluid micro-foaming screw rod mixing device and method, and belongs to the technical field of polymer processing and forming machines. The supercritical fluid micro-foaming screw rod mixing device comprises a device barrel and a micro-foaming screw rod driven by a power device; the micro-foaming screw rod is provided with a screw rod center blind hole and supercritical fluid supplying holes; the open end of the screw rod center blind hole is connected with a gas conveying opening of a supercritical fluid generator; and the multiple supercritical fluid supplying holes are evenly distributed in the circumferential direction of the micro-foaming screw rod, one ends of the supercritical fluid supplying holes communicate with the screw rod center blind hole, and the other ends of the supercritical fluid supplying holes communicate with a space between the micro-foaming screw rod and the device barrel. The method adopts the device, a supercritical fluid conducts circumferential gas injection from the interior of the micro-foaming screw rod to a polymer melt, and thus the supercritical fluid in an initial state is circumferentially and evenly dispersed in the polymer melt; and in addition, the micro-foaming screw rod is provided with a grooved multiple thread structure with a turbulence nail, and the mixing homogenization capacity of the screw rod is improved.

Description

technical field [0001] The invention belongs to the technical field of polymer processing and molding machinery, and in particular relates to a supercritical fluid micro-foaming screw mixing device and method. Background technique [0002] with supercritical CO 2 or N 2 The micro-foaming technology, which is a physical foaming agent, is becoming more and more popular all over the world due to its advantages of high dimensional stability, low residual stress, and light weight, and is widely used in the fields of injection molding and extrusion molding. Micro-foam molding requires filling the melt with a supercritical fluid foaming agent, and the supercritical fluid must be uniformly dispersed in the polymer melt to form a polymer / supercritical fluid homogeneous system. Polymer / supercritical fluid homogeneous system is the key stage of micro-foaming molding. This process directly affects the subsequent cell nucleation and growth. Therefore, the mixing and homogenization abil...

AI Technical Summary

Problems solved by technology

The flight of the traditional screw mixing device is simple and inefficient, which cannot make the supercritical fluid evenly distributed in the polymer melt, and quickly form a stable polymer / supercritical fluid homogeneous system

In addition, in the actual processing process, since the plane of the supercritical fluid supply hole is closely attached to the outer surface of the melt in a large area, it is easy to cause hole blockage

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