DE-102022101946-B4 - Printhead cleaning device for a 3D printer, 3D printer, use of the printhead cleaning device for a 3D printer, method for cleaning a printhead of a 3D printer, method for cleaning a wiping element of a printhead cleaning device of a 3D printer, and method for preserving a printhead of a 3D printer.

DE102022101946B4DE 102022101946 B4DE102022101946 B4DE 102022101946B4DE-102022101946-B4

Abstract

Printhead cleaning device (10) for a 3D printer configured to build a component layer by layer using binder jetting, wherein the printhead cleaning device (10) comprises: a carrier (12) on which a wiping element (14) is arranged and which has a plurality of nozzles (16) which are designed to dispense liquid cleaning agent, wherein the carrier (12) is rotatably supported on a holding structure (18) of the printhead cleaning device (10) and the printhead cleaning device (10) has a rotary drive (28) for rotating the carrier (12), and/or wherein the nozzles (16) form a first nozzle row (30) in which a plurality of nozzles (16) are arranged one after the other along the wiper element (14) and adjacent to it on the carrier (12), and a second nozzle row (32) in which a plurality of nozzles (16) are arranged one after the other along the wiper element (14) and adjacent to it on the carrier (12), and the first nozzle row (30) and the second nozzle row (32) are arranged on different sides of the wiper element (14), and/or wherein the wiper element (14) has a Y-shape in cross-section, one leg of which is held by the carrier (12) and the two remaining legs each form a wiper lip (38, 40) which are different from each other.

Inventors

Christoph Hauck
Christian Heufelder
Johannes Hillmann

Assignees

EXONE GMBH

Dates

Publication Date: 20260513
Application Date: 20220127

Claims (20)

Printhead cleaning device (10) for a 3D printer configured to build a component layer by layer using binder jetting, wherein the printhead cleaning device (10) comprises: a carrier (12) on which a wiper element (14) is arranged and which has a plurality of nozzles (16) configured to dispense liquid cleaning agent, wherein the carrier (12) is rotatably supported on a holding structure (18) of the printhead cleaning device (10) and the printhead cleaning device (10) has a rotary drive (28) for rotating the carrier (12), and/or wherein the nozzles (16) form a first row of nozzles (30) in which a plurality of nozzles (16) are arranged one after the other along the wiper element (14) and adjacent to it on the carrier (12), and a second row of nozzles (32) in which a plurality of nozzles (16) are arranged one after the other along the wiper element (14) and adjacent to it on the carrier (12), and the first row of nozzles (30) and the second row of nozzles (32) are arranged on different sides of the wiper element (14). are, and/or wherein the wiper element (14) has a Y-shape in cross-section, one leg of which is held by the carrier (12) and the two remaining legs each form a wiper lip (38, 40) which are different from each other.
Printhead cleaning device (10) after Claim 1 , wherein the wiping element (14) and the nozzles (16) are configured such that the wiping element (14) is at least partially wettable by the liquid cleaning agent dispensed from the nozzles (16), for example, by being rinsed and/or washed off.
Printhead cleaning device (10) after Claim 1 or 2 , wherein the nozzles (16) are configured such that an output area (62) of a printhead (56) to be cleaned can be wetted by the liquid cleaning agent dispensed from the nozzles (16) when the printhead (56) is positioned above the printhead cleaning device (10).
Printhead cleaning device (10) according to one of the Claims 1 until 3 , wherein the retaining structure (18) forms a trough-shaped depression (20), and the support (12) is supported, for example, on two opposite side walls (22, 24) of the depression (20) formed by the retaining structure (18).
Printhead cleaning device (10) according to one of the Claims 1 until 4 , wherein the printhead cleaning device (10) has a lifting drive (66) for adjusting the height of the support structure (18), and/or wherein the support (12) is at least partially, for example completely, in the recess (20) made of Claim 4 is arranged.
Printhead cleaning device (10) according to one of the Claims 1 until 5 , wherein a longitudinal axis (L3) of the wiper element (14) and a longitudinal axis (L1) of the first row of nozzles (30) are parallel to each other.
Printhead cleaning device (10) according to one of the Claims 1 until 6 , wherein the longitudinal axis (L3) of the wiper element (14) and a longitudinal axis (L2) of the second row of nozzles (32) are parallel to each other.
Printhead cleaning device (10) according to one of the Claims 1 until 7 , wherein the carrier (12) has a first line (34) fluidly connected to the first nozzle row (30) and a separate second line (36) fluidly connected to the second nozzle row (32), and wherein optionally the first line (34) has a first line section (34a) fluidly connected to a first section (30a) of the first nozzle row (30) and a separate second line section (34b) fluidly connected to a second section (30b) of the first nozzle row (30), and the second line (36) has a third line section (36a) fluidly connected to a first section (32a) of the second nozzle row (32) and a separate fourth line section (36b) fluidly connected to a second section (32b) of the second nozzle row (32).
Printhead cleaning device (10) according to one of the Claims 1 until 8 , wherein the two wiping lips (38, 40) have different geometric cross-sectional shapes, for example to achieve different cleaning effects, wherein, for example, a free end of a first wiping lip (38) has a round shape in cross-section and/or a free end of a second wiping lip (40) has a tapered shape in cross-section, for example a trapezoidal shape, for example an isosceles trapezoidal shape, and/or, for example, are made of different materials, for example to achieve different wiping effects, wherein, for example, a first wiping lip (38) has a felt or a sponge, for example to assist in cleaning the output area (62) of the printhead (56) to be cleaned, and/or a second wiping lip (40) has a rubber, for example to assist in drying the output area (62) of the printhead (56) to be cleaned, and/or wherein the wiping element (14) is arranged interchangeably on the carrier (12).
Printhead cleaning device (10) according to one of the Claims 1 until 9 , whereby the carrier (12) a flat surface (42), for example a strip-shaped flat surface, is formed in which the nozzle openings (44) of the nozzles (16) open and from which the wiping element (14) projects.
Printhead cleaning device (10) according to one of the Claims 1 until 10 , further comprising a suction device (46) having one or more elongated suction slots (48) and being configured to draw fluid, for example from the printhead (56) to be cleaned, through the elongated suction slot(s) (48), wherein optionally the suction device (46) is arranged such that longitudinal axes (L5) of the suction slots (48) and a longitudinal axis (L4, L3, L1, L2) of the carrier (12) and/or the wiping element (14) and/or the first row of nozzles (30) and/or the second row of nozzles (32) are arranged parallel to each other.
Printhead cleaning device (10) according to one of the Claims 1 until 11 , further comprising a control device (68) which is configured to variably adjust a volume flow of the liquid cleaning agent exiting the nozzles (16), for example by controlling a pump (50) and/or a valve (52), wherein optionally the volume flow can be variably adjusted by the control device (68) such that a liquid bubble (54) filled with the liquid cleaning agent is formed in which at least one free end section of the wiping element (14) is received, and wherein optionally the volume flow can be variably adjusted by the control device (68) such that the height of the liquid bubble (54) filled with the liquid cleaning agent can be variably adjusted.
3D printer (58) comprising: a printhead cleaning device (10) comprising a carrier (12) on which a wiping element (14) is arranged and which has a plurality of nozzles (16) configured to dispense liquid cleaning agent; a printhead (56) for selectively printing particle material using the binder jetting process; and a control device (60) configured to move the printhead (56) over the printhead cleaning device (10) for cleaning, and, during a first movement of the printhead (56) over the printhead cleaning device (10), to dispense liquid cleaning agent from the nozzles (16) such that an output area (62) of the printhead (56) is at least partially, for example completely, wetted with liquid cleaning agent, and, during a second movement of the printhead (56) over the printhead cleaning device (10), to dispense no liquid cleaning agent from the nozzles (16). to output nozzles (16).
3D printer (58) according to Claim 13 , wherein the control device (60) is further configured to set the carrier (12) into a second position in which the wiper element (14) is in contact with the output area (62) of the printhead (56) during the second movement of the printhead (56) over the printhead cleaning device (10), and optionally to set the carrier (12) into a first position in which the wiper element (14) is not in contact with the output area (62) of the printhead (56) during the first movement of the printhead (56) over the printhead cleaning device (10).
Use of the printhead cleaning device (10) according to one of the Claims 1 until 12 for cleaning and/or preserving a printhead (56), for example a binder jetting printhead (56) of a 3D printer (58).
A method for cleaning a printhead (56) of a 3D printer configured to build a component layer by layer using binder jetting, comprising: dispensing liquid cleaning agent from a plurality of nozzles (16) of a printhead cleaning device (10), firstly moving the printhead (56) over the printhead cleaning device (10) such that an output area (62) of the printhead (56) is at least partially, for example completely, wetted with the dispensed liquid cleaning agent, terminating the dispensing of liquid cleaning agent, and subsequently, a secondly moving the printhead (56) over the printhead cleaning device (10) such that the output area (62) of the printhead (56) is at least partially, for example completely, wiped by a wiping element (14) of the printhead cleaning device (10), whereby, during the first movement of the printhead (56) over the liquid cleaning agent is dispensed over the printhead cleaning device (10) on the first pass, and no liquid cleaning agent is dispensed on the second pass of the printhead (56) over the printhead cleaning device (10).
Procedure according to Claim 16 , wherein the first movement is in a first direction and the second movement is in a second direction, wherein the first direction and the second direction are different from each other, and wherein optionally the first direction and the second direction are opposite to each other.
Procedure according to Claim 16 or 17 , furthermore showing: Providing a printhead cleaning device (10) according to one of the Claims 1 until 12 , and optionally rotating and/or adjusting the height of the carrier (12) so that, on the first movement of the printhead (56) over the printhead cleaning device (10), the wiping element (14) does not make contact with the output area (62) of the printhead (56), and/or rotating and/or adjusting the height of the carrier (12) so that, on the second movement of the printhead (56) over the printhead cleaning device (10), the wiping element (14) makes contact with the output area (62) of the printhead (56) in order to wipe the latter.
Procedure according to one of the Claims 16 until 18 , wherein, during the second movement of the printhead (56) over the printhead cleaning device (10), for example after wiping the output area (62) of the printhead (56) with the wiping element (14), the printhead (56) is moved over a/the suction device (46) so that fluid adhering to the output area (62) of the printhead (56) is suctioned away.
A method for cleaning one or more printheads (56) of a 3D printer configured to build a component layer by layer using binder jetting, the method comprising: dispensing a first liquid cleaning agent from a plurality of first nozzles (16) of a printhead cleaning device (10) and simultaneously first moving a first printhead (56) or a second printhead (56) over the printhead cleaning device (10) so that a first section of an output area (62) of the first printhead (56) is completely wetted with the first liquid cleaning agent, or an output area (62) of the second printhead (56) is completely wetted with the first liquid cleaning agent, subsequently, a second moving of the first printhead (56) or the second printhead (56) over the printhead cleaning device (10) so that the first section of the output area (62) of the first printhead (56) is completely wetted by a The wiping element (14) of the printhead cleaning device (10) is wiped, or an output area (62) of the second printhead (56) is completely wiped by the wiping element (14) of the printhead cleaning device (10), dispensing a second liquid cleaning agent, different from the first liquid cleaning agent, from a plurality of second nozzles (16) of the printhead cleaning device (10), which are different from the first nozzles (16) of the printhead cleaning device (10), and simultaneously, a third movement of the first printhead (56) or a third printhead (56) over the printhead cleaning device (10), so that a second section of the output area (62) of the first printhead (56) is completely wetted with the second liquid cleaning agent, or an output area (62) of the third printhead (56) is completely wetted with the second liquid cleaning agent, and subsequent, a fourth movement of the first printhead (56) or of the third printhead (56) over the printhead cleaning device (10), so that the second section of the output area (62) of the first printhead (56) is completely wiped by the wiping element (14) of the printhead cleaning device (10) or an output area (62) of the third printhead (56) is completely wiped by the wiping element (14) of the printhead cleaning device (10), whereby optionally no liquid cleaning agent is dispensed on the second and/or fourth movement of the printheads (56) over the printhead cleaning device (10).

Description

The present invention relates to a printhead cleaning device for a 3D printer configured to build a component layer by layer using binder jetting, a 3D printer with the printhead cleaning device, the use of the printhead cleaning device, various methods for cleaning one or more printheads of a 3D printer, and a method for preserving a printhead of a 3D printer. Various additive manufacturing processes or 3D printing processes (and consequently various types of 3D printers, i.e., machines/systems for the layer-by-layer construction of a component) are known. Some additive manufacturing processes have the following steps in common: (1) Particle material (or particulate building material) is first applied over the entire surface/throughout a building area to form a layer of unsolidified particle material. (2) The applied layer of non-solidified particle material is selectively solidified in a predetermined sub-area (corresponding to the component to be manufactured), for example by selective printing of (e.g. liquid) treatment agent, for example binder, for example binder. (3) Steps (1) and (2) are repeated to produce a desired component. For this purpose, for example, a build platform on which the component is built up layer by layer can be lowered by one layer thickness before a new layer is applied (alternatively, for example, a recoater and a printing device can each be raised by one layer thickness). (4) Finally, the manufactured component, which is formed from the solidified sub-areas and is supported and surrounded by loose, non-solidified particle material, can be unpacked. The construction space in which the component(s) are manufactured can be defined, for example, by a so-called construction box (also called a "job box"), such as a swap body. Such a construction box can have an open-topped, vertically extending perimeter wall structure (for example, formed by four vertical side walls), which may be rectangular in plan view. A height-adjustable construction platform can be accommodated within the construction box. The space above the construction platform and between the vertical perimeter wall structure can, for example, at least partially define the construction space. An upper area of the construction space can, for example, be referred to as the build area. A construction box is used, for example, in the DE 10 2009 056 696 A1 described. The layer-by-layer construction of one or more three-dimensional components in a/the construction space can be achieved, for example, by selectively solidifying several adjacent layers of building material in a respective sub-area thereof, for example by binder jetting, i.e. by (selectively) “bonding” the (particle-shaped) building material with a (for example, liquid) treatment agent, for example, binder. In the above step (1), a recoater is typically used. Various recoaters are known for use in 3D printers, which can apply a particulate building material to the build area (also called build surface or build area) in the form of a uniform, full-surface/continuous layer. One type of coating machine uses a roller (referred to as a "roller coater") in front of which a quantity of particulate building material is first deposited. The roller is then moved horizontally across the construction area to apply the particulate building material in a uniform layer. The roller can rotate in the opposite direction during this process. Another type of coater (so-called "container coater," for example, "slot coater") uses a container that defines an internal cavity for receiving particulate building material and has a (for example, elongated) output area, for example, featuring a (for example, elongated) output slot, for dispensing the particulate building material. The container coater can, for example, be moved across a build area (for example, horizontally, for example, perpendicular to its longitudinal direction), whereby the particulate building material can be dispensed through the (elongated) output area onto the build area to apply a uniform, continuous layer of building material to the build area or platform. The coater can, for example, be elongated to span or cover the length or width of a rectangular build area. Coaters are used, for example, in DE 10 2009 056 689 A1 and EP 3 753 709 A1 described. In the above step (2), for example, a printing device with a printhead can be used for in A process called "binder jetting" involves applying a treatment agent (e.g., liquid) to a specific area of a previously applied layer of building material. This treatment agent contributes to the (immediate and/or subsequent) hardening of the building material layer in that area. For example, the treatment agent can be a binder, such as a binder compound, or a binder component of a multi-component binder. The treatment agent to be printed may be viscous and/or may, under certain circumstances, adhere to an output area (e.g., treatment agent output area) of the printhead, for example, t