Multi-material synchronous fed FDM spray head

Abstract

The invention belongs to the field of 3D printing fused deposition modeling, and discloses a multi-material synchronous fed FDM spray head. The spray head comprises a feeding unit, a mixing chamber, apneumatic extrusion unit and a nozzle, wherein materials enter the mixing chamber from the feeding unit, then are stirred and uniformly mixed, enter the nozzle under the action of the pneumatic extrusion unit and are extruded; and the feeding unit comprises a plurality of feeding ports, each feeding port is provided with a funnel, an upper pneumatic butterfly valve, a transition bin and a lower pneumatic butterfly valve, after the materials are added into the funnels, the upper pneumatic butterfly valves are opened to enable the materials to enter the transition bins, then the lower pneumaticbutterfly valves are opened to enable the materials to enter the mixing chamber, in the process, the upper pneumatic butterfly valves and the lower pneumatic butterfly valves are opened separately step by step, so that external gas is prevented from entering the mixing chamber, air pressure in the mixing chamber is ensured, and meanwhile the materials in the mixing chamber are prevented from being oxidized. According to the spray head, extrusion forming of complex parts including different types and different gradient materials is realized, the forming time is shortened, and the forming efficiency and the forming precision are improved.

Description

technical field [0001] The invention belongs to the field of 3D printing fused deposition, and more specifically relates to an FDM spray head for synchronous feeding of multiple materials. Background technique [0002] Fused Deposition Modeling (FDM) is a forming method in additive manufacturing that uses molten materials and deposits them on the processing plane. Due to the small diameter of the outlet and the high-precision X, Y and Z coordinates control, it can form three-dimensional parts with complex shapes and internal structures that are difficult to process. Due to its relatively low cost and ease of use, FDM is the most widely used forming method in additive manufacturing. The material used in the FDM forming method is mainly PLA, and the printed parts have a certain strength, which is very suitable for the construction of rapid models, making it used in teaching models, shopping mall exhibitions, and maker education. In the FDM printing process, only the nozzle p...

AI Technical Summary

Problems solved by technology

However, since multi-materials involve different materials to be accurate to the specific position of the part, there are many problems to be overcome, such as: uniform mixing of different materials, accurate feeding of different materials, etc. For the FDM forming method, multi-nozzles are used for multi-material printing At the same time, the repeated positioning of multiple nozzles, the uniform mixing of materials, and the real-time rapid change of materials during the printing process are all difficult problems. Because it uses metal rods for heating, the heating temperature that can be achieved is limited, so there is nothing to do with high melting point metal materials.

In the prior art, multiple nozzles are used to process various materials. In this method, when switching nozzles, the position of the converted nozzle needs to be repositioned to reach the end position of the previous nozzle. This process takes a long time and requires repositioning. Errors are easy to occur during the process; in addition, the existing technology is very difficult to realize the model with rapid changes in the gradient of the printing material. For example, the first layer of the gradient material is materials A and B with a mass ratio of 1:3, and the second layer is a mass ratio of 1. : 2 materials C and D, etc., if only one nozzle is used in the printing process in the prior art, for materials with different gradients, it is necessary to print one material and then stop the machine, then weigh the material for replacement, and start the machine. It needs to be repeated continuously, the whole process takes a long time and the process is cumbersome; if multiple nozzles are used in printing, different materials are loaded into each nozzle in advance, and the position of the nozzle needs to be adjusted when the nozzle is switched. The accuracy is difficult to guarantee and time-consuming. Therefore, for large-scale gradient materials, the existing nozzles cannot print at all due to the cumbersome process, long time-consuming, and difficulty in ensuring accuracy.

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