RU213762U1 - 3D printer printing device - Google Patents

Abstract

The utility model relates to means for manufacturing three-dimensional products by layer-by-layer printing with a melted polymer - 3D printing. The required technical result, which consists in improving the print quality and improving the reliability of operation, is achieved in a device containing an extruder configured to load a thermoplastic polymer into the extruder screw pair, heat it and supply the melt to the end of the extruder screw pair, as well as a spinneret for supplying the melt to the medium when performing volumetric printing, at the same time a screw pump of the melt is introduced, made in the form of a screw pair of the pump, driven by a drive installed at its beginning, and heated along its length, while at the end of the screw pair of the pump a window is made for receiving the melt from the screw pairs of the extruder and its supply to the die. 1 ill.

Description

The utility model relates to means for manufacturing three-dimensional products by layer-by-layer printing with a melted polymer - 3D printing.

In the process of 3D printing with a thermoplastic material, during the layer-by-layer formation of a product, in order to ensure a smooth surface of the part, it becomes necessary to stop the flow of material melt from the nozzle of a 3D printer. The need to stop the supply of the melt occurs during idle transitions between print islands and during the transition of the printing die to the beginning of the next printing layer.

If a 3D printer is not equipped with a high-speed melt flow termination system, then bumps appear on the printed surface at the transition points and melt threads are pulled behind the printing die, which also do not improve print quality. Particularly unpleasant are large bumps that can cling to the printing die, which leads to a deterioration in print quality and even to a stop in the printing process.

In 3D printers using filament or rod as the print material, the retraction process is simply carried out by rolling back the rod in the extruder, which causes the melt filament to be sucked into the die.

In the case of building a 3D printer based on a high-performance screw extruder, rolling back or turning the screw in the opposite direction from the working direction is impossible, because in this case, the melt will be fed into the cooled loading zone and the material will stick to the screw. The extruder stops picking up new material, the plasticization stops and the printing process stops.

Thus, when using 3D printer printing devices, there is a problem of improving the quality and reliability of printing.

Known printhead 3D printer [RU 189770, U1, V29S 64/209, 06/03/2019] containing a housing and extruders, each of which consists of a nozzle, a heating and cooling element, connected to a radiator rigidly connected to the linear guide slider, as well as an extruder switching mechanism with a drive connected to the control system, while the extruder switching mechanism consists of a rotation drive connected to a shaft on which an end cam is installed, interacting with a pusher made in the form of a finger rigidly connected to the slider of the linear guide, and also by the fact that a disc is installed on the shaft associated with the rotation drive, shielding non-working nozzles.

The disadvantage of this technical solution is the relatively high complexity.

A known printing unit of a 3D printer [RU 177332, U1, B41J 2/00, 02/15/2018], containing a print head, a pump and a container for storing working material, which are connected to each other by means of hoses, moreover, a bypass valve is installed at the pump outlet, connected by a hose to a container for storing the working material, while the print head contains a contour head and a print unit located on the same axis.

The disadvantage of the devices is the relatively poor print quality.

The closest in technical essence to the proposed one is the device [RU 203882, U1, V29C 48/395, 04/26/2021], containing an electric motor connected to a housing in which there is an inlet fitting for feeding granules, a cylinder with an auger installed in it, a heater and nozzle located on the cylinder, moreover, the electric motor is equipped with a gearbox, the inlet fitting for supplying granules is made with gas outlet holes, the fitting of the liquid cooling system, the liquid cooling labyrinth and the sensor for monitoring the presence of granules are installed in the housing, the screw is made with a constant helical groove width, but with a variable area, and contains loading, compression, homogenization and dosing zones, the cylinder has three heating sections, each of which has one to two heaters and one temperature control sensor.

The disadvantage of the closest technical solution is the relatively low print quality and relatively low reliability.

The objective of the utility model is to create a 3D printer printing device that provides improved print quality and has increased reliability.

The desired technical result is to improve the print quality and reliability of the device.

The problem is solved, and the required technical result is achieved by the fact that in a device containing an extruder made with the possibility of loading a thermoplastic polymer into the screw pair of the extruder, heating it and supplying the melt to the end of the screw pair of the extruder, as well as a spinneret for supplying the melt to the carrier when performing volumetric printing, according to the utility model, a screw pump of the melt is introduced, made in the form of a screw pair of the pump, driven by a drive installed at its beginning, and heated along its length, while at the end of the screw pair of the pump there is a window for receiving the melt from the screw pair of the extruder and its supply to the spinneret.

The drawing shows a 3D printer printing device.

The drawing shows

1 - extruder;

2 - drive of the screw pair of the extruder;

3 - extruder loading zone;

4 - screw pair of the extruder;

5 - screw pair of the pump;

6 - die;

7 - drive of the screw pair of the pump;

8 - window for receiving the melt from the screw pair of the extruder

The printing device of the 3D printer contains an extruder 1 configured to load a thermoplastic polymer into the screw pair 4 of the extruder, heat it and supply the melt to the end of the screw pair 4 of the extruder.

The device also contains a die 6 for supplying the melt to the carrier when performing volumetric printing.

In addition, the device contains a melt screw pump, made in the form of a screw pair 5 of the pump, driven by a drive (for example, a servomotor) installed at its beginning, and heating it along the length, while at the end of the screw pair 5 of the pump, a window 8 is made for receiving the melt from the screw pair 4 of the extruder and feeding it into the spinneret 6.

The 3D printer print device works as follows.

The extruder 1 feeds the melt into the melt receiving window 8 from the screw pair 4 of the extruder, to which it is hermetically attached via an adapter or directly. The receiving window 8 is located from the middle and below in the direction of the melt, and the melt is heated above and below the window 8 to the spinneret 6 inclusive.

This design makes it possible to stop the extruder 1 by short-term reverse rotation of the screw pair 5 of the pump to quickly reduce the pressure in the die 6. This eliminates spontaneous outflow of the melt after stopping the screw pair 4 of the extruder.

Thus, in the process of printing, the appearance of bumps is excluded and threads from the melt do not stretch behind the spinneret. This improves the quality of printing and the reliability of the device, which achieves the desired technical result.

Claims (1)

A device for 3D printing with a molten polymer, comprising an extruder and a spinneret connected by a screw pair for supplying the polymer melt to the carrier during printing, while the extruder is configured to load a thermoplastic polymer into it and heat it to obtain a polymer melt, characterized in that it is equipped with a screw a polymer melt pump made in the form of a screw pair with a rotation drive, having a window for receiving the polymer melt and feeding it into the die, wherein the screw pair of the extruder is hermetically connected to the said window, and the screw pair of the pump is made with the possibility of heating it along the length and reverse rotation, providing pressure reduction in the die.

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