A fluid circulation temperature controlled fusion deposition forming print head

Abstract

A fluid circulation temperature-controlled fusion deposition forming print head, including a cooling pipe, a threaded pipe outside the cooling pipe, a cooling liquid inlet pipe and a cooling liquid outlet pipe inside the cooling body, the cooling liquid inlet pipe, the threaded pipe, and the cooling liquid outlet pipe are common Consists of the internal circulation pipe of the coolant in the print head, the coolant inlet pipe is connected to the outlet of the coolant inlet pipe through the coolant inlet pipe joint, the inlet of the coolant inlet pipe is connected to the outlet of the water pump, and the inlet of the water pump is outlet through the radiator The water pipe is connected to the outlet of the radiator, and the inlet of the radiator is connected through the coolant outlet pipe, the coolant outlet pipe joint and the coolant outlet pipeline to form a fluid circulation system. Reduce the throat temperature in time, improve the gap backflow during high-temperature printing, and maintain stable printing accuracy during long-term continuous printing.

Description

technical field [0001] The invention belongs to the technical field of 3D printing, and in particular relates to a fluid circulation temperature-controlled fusion deposition forming printing head. Background technique [0002] Fused Deposition Modeling (Fused Deposition Modeling, FDM) is to heat the filamentous hot-melt material to a molten state and extrude it from the nozzle. The nozzle moves according to the cross-sectional profile of the part, and the extruded material is deposited on a predetermined trajectory along with the movement of the nozzle. , a forming method that forms a solid by layer-by-layer accumulation. Because the FDM process is simple and the equipment cost is low, it has gained a broad market space. [0003] A typical FDM printer generally adopts a plunger-type print head structure, which is mainly composed of a heat dissipation block, a throat, a heating block, and a nozzle. This type of print head uses friction as a power to push the unmelted materi...

AI Technical Summary

Problems solved by technology

On the one hand, because the inner diameter of the throat is larger than the diameter of the wire, if the heat dissipation of the throat is not timely, the molten material in the front section will not only be extruded from the nozzle, but will also form a backflow in the gap between the throat and the wire, so that the wire and the throat The friction between them increases, and even causes the material to overflow from the back end of the throat, resulting in no silk

On the other hand, since the filament is extruded from the nozzle, it relies on the forward thrust of the unmelted material at the rear. As the printing time increases, if the temperature at the rear end of the throat reaches the glass transition temperature of the material, the filament will soften and move forward. The smaller the thrust, the smaller the amount of spinning, the narrower the width of the wire extrusion, and the lower the accuracy of the parts

Especially for high-performance polymers such as polyether ether ketone and polyimide, on the one hand, the viscosity of the material is high, and the tolerable gap backflow distance itself is shorter than that of ABS and PLA. In addition, the material has a high melting point, and the nozzle printing temperature is generally 350°C Above, it is difficult for the traditional heat dissipation block to reduce the temperature of the rear end of the throat below the glass transition temperature of the material, so the phenomenon of "plugging" often occurs

In summary, for materials with high melting point and high viscosity such as polyether ether ketone and polyimide, the existing print head structure cannot meet the heat dissipation requirements of the throat, and cannot achieve long-term continuous fine printing of such materials

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