When the twin-screw extruder forms the profile, the phenomenon of exhaust hole emitting material, how to solve it?

The main causes are as follows: 
When the twin-screw extruder is used to produce profiles, there are generally two exhaust holes on the barrel to facilitate the discharge of gases or volatiles in the material, so as to ensure the quality of the material plasticization and product quality. If there is an air vent during the molding process, it is easy to block the air hole, resulting in extrusion fluctuations, affecting the stability of extrusion and profile quality. The main reasons for the extruder exhaust hole ejection and powder extraction are: 
(1)The supply amount of the twin-screw extruder is inconsistent with the amount of extruded material, the material supply of the extruder exceeds the extrusion amount of the screw, and the excess material will inevitably be continuously squeezed to the exhaust hole with low pressure under the action of pressure, resulting in the material emerging from the exhaust hole and finally blocking the exhaust hole - this is the reason for the most material emitting from the extruder exhaust hole; 
(2)The extrusion temperature control is unreasonable, the material has been excessively plasticized when it arrives at the exhaust area of the extruder, and the gas and volatile matter are wrapped in the material and difficult to escape, due to the sudden drop in the pressure of the exhaust area, the melt will produce a relatively large expansion, and the scraping phenomenon may occur at the exhaust hole, and the accumulation or even scorching at the exhaust hole will be blocked.     
 The usual solutions are mainly as follows: 
(1)set a reasonable process temperature of the main engine feeding area and compression area to ensure the appropriate plasticization degree of the material, and generally require that the density of the material should be controlled at 1.0~1.2g/ml when it reaches the exhaust area; 
(2)The speed of the main screw and the speed of the feeding screw are properly controlled, so that the extrusion volume and the feeding amount are basically the same; 
(3) Control the vacuum degree of the extruder exhaust to meet the requirements, and clean the exhaust port in time.
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