3D printing nozzle, 3D printer and printing method
A 3D printing nozzle, a 3D printer and a printing method are provided. The 3D printing nozzle includes a nozzle body to convey and extrude a printing material along a target direction, and sequentially includes at least a preheating section, a first heat resistance section, and a melting section along the target direction; and a heating device connected to the nozzle body. During operation, the heating device heats the preheating section to a temperature T1, and the melting section to a temperature T2. The printing material remains solid when passing through the preheating section at the temperature of T1; the printing material turns into a fluid state when passing through the melting section at the temperature T2, The first heat resistance section restricts the heat conduction between the preheating section and the melting section, so that the printing material in the preheating section remains in the solid state.
1 . A 3D printing nozzle, comprising:
a nozzle body, being configured to convey and extrude a printing material along a target direction during operation, and sequentially comprising one preheating section, a first heat resistance section, and a melting section along the target direction, wherein
the first heat resistance section comprises a first end and a second end, the first end is connected to the preheating section and the second end is connected to the melting section to restrict heat conduction between the preheating section and the melting section; and
a heating device, connected to the nozzle body, being configured to heat the preheating section to a temperature T1 to keep the printing material in a solid state and to heat the melting section to a temperature T2 to turn the printing material to a fluid state during the operation,
wherein outer diameters of two ends of the first heat resistance section are larger than an outer diameter of a middle portion of the first heat resistance section; and
the two ends of the first heat resistance section are respectively connected to the preheating section and the melting section.
2 . The 3D printing nozzle according to claim 1 , wherein
the printing material is a semi-crystalline polymer with a crystallinity of greater than 0;
the semi-crystalline polymer has a maximum melting point of T m ; and
the T1, the T2, and the T m satisfy the following relationship: T1<T m ≤T2.
3 . The 3D printing nozzle according to claim 1 , wherein
the printing material is a non-crystalline polymer;
the non-crystalline polymer has a maximum glass transition temperature of T g ; and
the T1, the T2, and the T g satisfy the following relationship: T1<T g ≤T2.
4 . The 3D printing nozzle according to claim 1 , wherein the printing material comprises at least one of polylactic acids, polyamides, polyethylene terephthalates, polyolefins, thermoplastic polyesters, polycarbonates, polyurethanes, polyphenylene sulfides, polyphenylene oxides, polyoxymethylenes, polysulfones, polyimides, polyetherether ketones, liquid crystal polymers, or copolymers of the foregoing.
5 . The 3D printing nozzle according to claim 1 , wherein the heating device is at least one of a resistance heater, a radiation heater, or an electromagnetic heater.
6 . The 3D printing nozzle according to claim 1 , wherein the heating device comprises:
a first heating device, connected to the preheating section, and configured to heat the preheating section to the temperature T1; and
a second heating device, connected to the melting section, and configured to heat the melting section to the temperature T2.
7 . The 3D printing nozzle according to claim 1 , wherein a difference between the thermal conductivity of the first heat resistance section and the thermal conductivity of the melting section is greater than or equal to 10 W/m·K.
8 . The 3D printing nozzle according to claim 1 , wherein
a material of the first heat resistance section comprises at least one of inorganic non-metallic materials or organic polymer materials; and
materials of the preheating section and the melting section comprise at least one of metal materials, metal alloys, or carbon materials.
9 . The 3D printing nozzle according to claim 1 , wherein a length of the first heat resistance section is greater than or equal to 1 mm.
10 . The 3D printing nozzle according to claim 1 , wherein
the nozzle body further comprises a conveying section and a second heat resistance section connected sequentially along the target direction, wherein
the second heat resistance section is connected to the preheating section, and
when the 3D printing nozzle is in the operation, the printing material is sequentially conveyed through the conveying section, the second heat resistance section, the preheating section, the first heat resistance section, and the melting section, and is finally extruded from an outlet.
11 . The 3D printing nozzle according to claim 10 , wherein
the conveying section and the second heat resistance section are connected by a heat dissipation section; and
a heat dissipation device is connected to the heat dissipation section.
12 . The 3D printing nozzle according to claim 11 , wherein outer diameters of two ends of the second heat resistance section are larger than an outer diameter of a middle portion of the second heat resistance section; and the two ends of the second heat resistance section are respectively connected to the preheating section and the heat dissipation section.
13 . The 3D printing nozzle according to claim 1 , wherein a thermal conductivity of the first heat resistance section is lower than a thermal conductivity of the preheating section and is lower than a thermal conductivity of the melting section.
14 . A 3D printer, comprising:
a nozzle, comprising:
a nozzle body, being configured to convey and extrude a printing material along a target direction during operation, and sequentially comprising one preheating section, a first heat resistance section, and a melting section along the target direction, wherein the first heat resistance section comprises a first end and a second end, the first end is connected to the preheating section and the second end is connected to the melting section to restrict heat conduction between the preheating section and the melting section; and
a heating device, connected to the nozzle body, being configured to heat the preheating section to a temperature T1 to keep the printing material in a solid state and to heat the melting section to a temperature T2 to turn the printing material to a fluid state during the operation; and
a filament conveying device to feed the printing material to the printing nozzle,
wherein outer diameters of two ends of the first heat resistance section are larger than an outer diameter of a middle portion of the first heat resistance section; and
the two ends of the first heat resistance section are respectively connected to the preheating section and the melting section.