Large 3D printing device based on granule screw extruder and working method of large 3D printing device

Abstract

The invention provides a large 3D printing device based on a granular material screw extruder and a working method of the large 3D printing device. The granular material screw extruder is fixed to a z-axis sliding rail of a rack and can only move in the z-axis direction; and an x-axis guide rail and a y-axis guide rail control a printing platform to move freely in the horizontal plane. In the printing process, a nozzle does not move in the x-y plane, and relative movement of the nozzle and the printing platform in the material deposition process is achieved through movement of the printing platform. The extruder is a fixed screw extruder, and the inertia effect of fluid in the extrusion device can be avoided, so that the stability of the material in the extrusion and deposition process is ensured. Printing is completed through movement of the printing platform on a two-dimensional plane. An infrared heating device connected with a servo motor is arranged at the nozzle and is used for secondarily heating a printed and formed part, so that the temperature gradient between a cooled deposition material and a hot-melt extrusion material is reduced, the cooled deposition material and the hot-melt extrusion material are better bonded with a newly extruded material, and the bonding strength between deposition layers is further improved.

Description

technical field [0001] The invention relates to the technical field of 3D printing, in particular to a large-scale 3D printing device based on a pellet screw extruder and a working method thereof. Background technique [0002] At present, the main structure of the main large-scale 3D printing device adopts a configuration similar to that of a desktop-level 3D printer. The pellet screw extruder is connected with the three-dimensional gantry frame to realize the extrusion and deposition of molten consumables in three-dimensional space, and the layers are piled up to form a three-dimensional structure. [0003] For desktop 3D printers, the material enters the extruder through a plastic hose. The diameter of the nozzle is generally about 0.4mm, and the volume of the extruded material per unit time is small. Therefore, when moving in a plane, the inertia of the molten fluid has little influence . However, the material extrusion flow rate of the pellet screw extruder can usually...

AI Technical Summary

Problems solved by technology

When the screw extruder is moved quickly in the plane, it will affect the stability of the material deposition process and the dimensional accuracy of the molded material

On the other hand, in order to reduce the influence of inertia, the driving speed of the screw extruder must be reduced, which also limits the molding efficiency of large-scale additive manufacturing devices

In addition, the volume of molded parts of large-scale additive manufacturing devices is generally large, so the transient temperature field changes greatly during the material deposition process, and the temperature gradient between the deposition layers is also large, which will cause hot-melt extruded materials and cooled deposited materials. A high-quality interlayer bond cannot be formed between layers, which reduces the mechanical properties of the molded part

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