Three-dimensional printing method

Abstract

The invention discloses a three-dimensional printing method, wherein a melt enters a three-dimensional printing device to print a finished product. The three-dimension printing device comprises a three-dimensional moving mechanism, a working platform mechanism and a computer control and driving system; the melt is made from a modified nylon material formed by a nylon resin matrix and a tackifying nucleating agent; the tackifying nucleating agent is prepared by compounding of ion liquid and nano carbon filler; and the ion liquid is formed by anions and cations, wherein the anions are alkyl imidazole ions. The device disclosed by the invention has the advantages of being simple and compact in structure, high in automation degree, easy to control, high in precision, high in efficiency and high in adaptability; the modified nylon material provided by the invention can effectively avoid edge warping during 3D printing; and a finally printed product has the advantages of being excellent in mechanical property, good in dimension stability, smooth in surface, low in cost and the like.

Description

technical field [0001] The invention belongs to the technical field of 3D printing, and in particular relates to a three-dimensional printing method with high precision, high efficiency and high adaptability. Background technique [0002] The fused deposition 3D printer is also called the fused extrusion rapid prototyping machine. This printer first layers and slices the 3D solid model of the formed part, and stores the cross-sectional information of the formed part in the STL format file; then, the filament It is sent from the wire feeding mechanism to the heating liquefaction pipe for heating and melting, so that the molten material is extruded from the heating nozzle according to the cross-sectional information and deposited on the workbench under the control of the computer, and is rapidly solidified to form a thin layer. After the deposition of one layer is completed, the workbench is lowered to the height of one layer (set as the slice thickness), and then the next lay...

AI Technical Summary

Problems solved by technology

The disadvantages caused by this are: (1) The molding material must first be prepared into a wire (about 1.75mm in diameter), so that there are certain requirements for the stretching, ductility, plasticity, etc. of the molding material; in addition, the selected material It is also necessary to ensure that the wire has sufficient bending strength to realize extrusion of the melt relying on the piston propulsion of the material wire itself. Therefore, the degree of freedom in the selection of molding materials is limited, and the cost of molding materials is increased.

(2) Due to the limited ability of the friction wheel conveying force and the anti-stabilization ability of the wire between the inlet of the liquefaction pipe and the wheel, the existing extrusion device cannot increase the molding speed, and the speed of the nozzle is 30-300mm / s; During the extrusion process, nozzle clogging often occurs, so that the diameter of the nozzle is about 0.1-0.5mm. At the same time, the hysteresis and salivation phenomenon of the nozzle cannot be overcome, which affects the molding accuracy and efficiency of the molded parts, and it is difficult to achieve high-efficiency molding of high-density workpieces.

The disadvantage is that for low-viscosity molding materials, salivation cannot be avoided during the molding process, and due to the limited increase in screw extrusion pressure, it is impossible to mold high-viscosity polymer materials, such as polycarbonate, polyphenol, etc.

The disadvantage is that this nozzle device still relies on the screw to increase the extrusion force, and cannot form high-viscosity polymer materials, such as polycarbonate, polyphenol, etc.

Among them, ABS resin is a two-phase heterogeneous structure with graft copolymer as the rubber phase and styrene-acrylonitrile as the matrix phase, so that it has the chemical resistance, oil resistance and surface hardness of acrylonitrile. Butadiene The cold resistance and toughness of styrene, the good dielectric properties, gloss and processability of styrene, but its mechanical strength is not high, and as the molecular weight increases, the processability decreases

However, PLA has poor mechanical properties and is prone to brittle fracture, especially in the process of melting and molding, which greatly limits the use of printed parts.

Among nylon materials, nylon 12 is currently used more, such as nylon 12 developed by Stratasys in the United States, mainly because nylon 12 has the lowest melting temperature among nylon materials, and its water absorption and molding shrinkage are relatively small. Most suitable as 3D printing material, but it is expensive and the mechanical properties of the product are poor

However, other pure nylon materials are greatly limited due to their molecular structure, mainly in high forming temperature, large forming shrinkage, slow crystallization speed, low melt viscosity and sag resistance when the processing temperature is higher than the melting point. The performance is poor. When printing with the fusion 3D printing technology, the filament extruded from the nozzle is prone to collapse on the forming platform. At the same time, due to the shrinkage between the layers, defects such as edge warping and even cracking occur, which affect the smooth progress and forming of the 3D printing process. piece performance

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