The dry powder-pressing fuse mold is in a viscous state when it is in use, passes through a die having a specific cross-sectional shape at a high temperature and a certain pressure, and then is shaped into a continuous profile of a desired cross-sectional shape at a lower temperature. a molding method. The production process of extrusion molding is to prepare molding materials, extrusion molding, cooling setting, drawing and cutting, and post-processing of extrusion products (tempering or heat treatment).
In the process of extrusion molding of dry powder pressing fuse mold, it is necessary to adjust the process parameters such as temperature, screw rotation speed and traction speed of each heating section of the extruder barrel and the die of the machine head to obtain qualified extruded profiles. Particular attention should be paid to adjusting the rate at which the polymer melt is extruded from the die. Because when the rate of extrusion of the melt is low, the extrudate has a smooth surface and a uniform cross-sectional shape, but when the extrusion rate of the molten material reaches a certain limit, the surface of the extrudate becomes rough and tarnished. , shark skin, orange peel, shape distortion and so on. As the extrusion rate is further increased, the surface of the extrudate is distorted, even fragmented and broken into melt fragments or cylinders. Therefore, the control of the extrusion rate is crucial.
Dry powder pressing fuse mold casting molding. The plastic raw material is added into the preheating feeding chamber, and then the pressing column is placed in the feeding chamber to lock the mold, and the pressure is applied to the plastic through the pressing column, and the plastic is melted into a flowing state under high temperature and high pressure, and enters the cavity through the pouring system. Gradually solidified into plastic parts.