Patent Description:
It also concerns components of an ink circuit of ClJ printers, for the purpose of increased flexibility. It also concerns a process for manufacturing such components.

Continuous inkjet printers (ClJ) are well known in the field of industrial coding and labelling of various products, for example to mark barcodes or expiry dates on food items or on packages for items directly on the production line and at fast production rate. This type of printer is also found in some fields of design in which use is made of the graphic printing possibilities of the technology.

The ink circuit of a CIJ printers comprise many components, such as fluid manifolds or connectors or dampers or stimulation bodies or even printing heads, which usually comprise several parts assembled together with sealing means, such as O rings or similar to ensure fluid tightness. The assembling of such parts is time consuming and there is a risk of leaks at the various interfaces.

For example such a component can comprise several parts in different materials, for example a first part in stainless steel and a second part in plastic fixed together by screws, O rings ensuring tightness at the interface between both parts. The first part can itself comprise various ducts and conduits which are formed by machining several blocks of stainless steel which are then assembled together. <CIT> discloses the preamble of claims <NUM> and <NUM>.

There is a need for fluid components of an ink circuit of such ClJ printers made of one piece whilst guaranteeing great flexibility and reliability, ease of maintenance to allow rapid servicing. Mounting such components should also be easier and faster than known components.

There is also a need for components for such an ink circuit which can be easily removed or disassembled from said ink circuit for example when they must be repaired or replaced by other components.

There is also a need for components which can be assembled with several parts of such an ink circuit o allow fluids to flow in different directions.

The invention first concerns a continuous inkjet (CIJ) printer, comprising:.

Preferably, said material is chemically resistant to ethanol, and/or methyl isopropyl ketone (MIPK) and/or methyl ethyl ketone (MEK).

Said fluid component can further comprise a chamber for a sensor and/or a chamber for a damper. At least part of the walls delimiting said chamber can have the limited roughness (Ra) mentioned above for the duct(s).

Said chemically resistant material can for example comprise stainless steel, or a ceramic material, or a plastic material or a glass material.

In a continuous inkjet (CIJ) printer according to the invention, said fluid component:.

At least one duct can comprise a directional transition having an edge with a radius of curvature tangential to a flow direction of the fluid in said duct or can have a curved shape with a finite, non-zero radius of curvature in at least one plane comprising at least a tangent to a flow direction of the fluid in said at least one duct. Said radius of curvature can for example be larger than <NUM>,<NUM>.

Said at least one fluid connection area can comprise at least one O-ring groove or counterbore around said at least one fluid inlet and/or said at least one fluid outlet.

In an example, said fluid component comprises at least two ducts, which can, for example:.

Said fluid component can comprise a succession of layers in said chemically resistant material, each layer having a thickness of between <NUM> and <NUM>.

At least part of a duct can have a wall with a thickness between <NUM> and <NUM>. Alternatively the duct(s) is/are embedded in a piece or a block of said chemically resistant material.

A continuous inkjet (CIJ) printer according to the invention can comprise an assembly of said fluid component, also designated as first fluid component, with a second fluid component connected with said fluid connection area of the first fluid component, wherein said second fluid component comprises a valve, or a pump, or a filter, or a damper, or a fluid connector or a hydraulic distributor, which comprises at least one fluid inlet and at least one fluid outlet which matches with or corresponds to said at least one of said at least one fluid inlet and said at least one fluid outlet of the first fluid component, so that at least one fluid can circulate from said first fluid component to said second fluid component and/or vice versa. Both first fluid component and second fluid component can be maintained in friction contact with each other: they can be rotated and/or translated relative to each other but remain in contact during the movement. No fluid can flow out of the device between both contact surfaces: the contact at the interface between both surfaces is watertight. Preferably, the surfaces or areas in friction contact have a roughness less than <NUM>, for example between <NUM>,<NUM> and <NUM>,<NUM>, thus not requiring any gasket so that the interface is watertight.

A continuous inkjet (CIJ) printer according to the invention can further comprise a print head connected to the ink circuit via a flexible umbilical cable, said cable containing hydraulic connection means to bring ink from the ink circuit to the print head and send ink to be recovered from the print head towards said ink circuit, and electrical connection means.

The invention also concerns a fluid component (or part, or one piece or monobloc fluid component or part) for a continuous inkjet printer, comprising:.

Said fluid component can be a one-piece fluid component made of a material chemically resistant to at least one organic solvent, for example ethanol, and/or methyl isopropyl ketone (MIPK) and/or methyl ethyl ketone (MEK).

At least part of said fluid connection area has a roughness (Ra) of less than <NUM> or <NUM> and at least part of the inner surface of said two ducts has a roughness (Ra) of less than <NUM>.

Said fluid connection area or surface is for a connection to another fluid component or part of a CIJ printer: through said at least one fluid inlet(s) and/or fluid outlet(s), a fluid can flow into, resp. from, said fluid component or part, from, resp. into, said other fluid component or part.

Preferably:
A fluid component according to the invention may comprise several ducts, for example at least <NUM> ducts, which may extend along parallel or non-parallel directions and/or intersecting with each other. Said at least <NUM> ducts may extend in a same plane or in different planes.

At least one duct can comprise a directional transition having an edge with a radius of curvature tangential to a flow direction of the fluid in said duct and/or can have a curved shape with a finite, non-zero radius of curvature in at least one plane comprising at least a tangent to a flow direction of the fluid in said at least one duct. Said radius of curvature can for example be larger than <NUM>, <NUM>.

If a fluid component or part according to the invention comprises at least <NUM> ducts, at least one mechanical link, for example a wall or one or more connecting beams, can link said at least <NUM> ducts together so that they remain mechanically fixed with respect to each other. Said at least one mechanical link can also be manufactured during a same additive manufacturing process as the rest of the component.

A fluid component according to the invention may comprise at least one chamber for a sensor and/or a damping chamber. At least part of the walls delimiting said chamber can have the limited roughness (Ra) mentioned above for the duct(s). A fluid component according to the invention can be for example in stainless steel or in a ceramic material or in a plastic material or in a glass material.

A fluid component according to the invention may be or comprise a fluid manifold and/or at least part of a printing head or a hydraulic distributor or a fluid damper or a fluid connector.

A fluid component according to the invention can comprise a succession of layers in said same material, for example said material chemically resistant to at least at least one organic solvent, for example ethanol and/or methyl ethyl ketone (MEK) and/or methyl isopropyl ketone (MIPK), each layer having for example a thickness of between <NUM> and <NUM>. This is in particular the case for a component made by a 3D printing process, where layers are successively deposited on each other or where layer of a same material are progressively processed, for example by a laser beam or by a jet of binder.

The duct(s) of a fluid component of a CIJ printer according to the invention or of a fluid component according to the invention can be embedded in a block or piece of material. Alternatively, at least part of one or more of said ducts can have a wall having a thickness comprised between <NUM> and <NUM> with no material beyond said wall: this saves material between the ducts and allows the component to be much lighter.

A fluidic component according to the invention can be assembled with or to at least another fluid component, for example at least a valve or a pump or a filter or a damper or a fluid connector or a hydraulic distributor, fixed against said fluid connection area, said other fluid component comprising at least one fluid inlet and at least one fluid outlet which matches or corresponds to said at least one of said fluid inlet and said fluid outlet of said fluid component. Thus, when both components are assembled at least one fluid can circulate from said fluid component to said other fluid component or vice versa. Both said fluid component according to the invention and said other fluid component can be maintained in friction contact with each other: they can be rotated and/or translated relative to each other but remain in contact during the movement. No fluid can flow out of the device between both contact surfaces: the contact at the interface between both surfaces is watertight. Preferably, the surfaces or areas in friction contact have a roughness less than <NUM>, for example between <NUM>,<NUM> and <NUM>,<NUM>, thus not requiring any gasket so that the interface is watertight.

The invention also concerns a continuous inkjet (CIJ) printer, comprising:.

The invention also concerns a process for manufacturing at least one fluid component or one-piece (or single bloc or monobloc) fluid component, for example as disclosed above and/or in the following description or at least one part of a CIJ printer, said fluid component or one-piece (or single bloc or monobloc) fluid component or part being according to the invention, as disclosed above and/or more generally in this description, said process comprising at least a step of additive manufacturing (or 3D printing).

The invention also concerns a process for manufacturing at least one fluid component or one-piece (or single bloc or monobloc) fluidic component or at least one part of a CIJ printer, said fluid component or one-piece (or single bloc or monobloc) fluid component or part comprising at least one duct, at least one fluid inlet and at least one fluid outlet, said process comprising a step of additive manufacturing (or additive printing or 3D printing) of:.

Said at least one fluid component or single bloc fluid component or part can in particular comprise at least one fluid connection area (or surface) comprising at least one of said fluid inlet(s) and said fluid outlet(s). Said above mentioned step of additive manufacturing can comprise manufacturing said at least one duct and said at least one fluid connection area; or said one piece or one bloc comprises said at least one or more duct and said at least one fluid connection area.

Said at least one fluid component or single bloc fluid component or part is preferably in a material chemically resistant to at least one organic solvent, for example ethanol and/or methyl ethyl ketone (MEK) and/or methyl isopropyl ketone (MIPK).

In a particular embodiment, said fluid component can comprises at least <NUM> ducts, each having at least one fluid inlet and at least one fluid outlet; said method may therefore comprise a step of additive manufacturing of said at least <NUM> ducts, possibly of at least one mechanical link between said ducts and possibly of said at least one fluid connection area (or surface) comprising at least one of said fluid inlet(s) and fluid outlet(s).

A process according to the invention may comprise a step of further processing the inner surface of at least part of said one or more duct(s) and/or of said at least one fluid connection area or surface if any of them does not have the required roughness. For example, said further processing may include a mechanical and/or a chemical processing of at least some portions of the component or part. Examples of said mechanical and/or a chemical processing are given in the detailed description.

The 3D printing process can be selected or adapted based on the required roughness for said duct(s) and/or fluid connection area; for example, said process may include selecting or adapting an angle of deposition of the material on a substrate so that some areas or portions have a better roughness than others.

Or the order in which the various portions of the component are to be printed in a build tank can be selected or adapted so that a better roughness is obtained on the area(s) for which this parameter is more critical. In particular, the final component can be oriented in a build tank so that a specific surface of said component has the required roughness Ra.

A one piece or monobloc fluid component or part obtained by a process according to the invention has no mechanical assembly zones and no screws or any other fastening means between different portions or parts. There is thus a mechanical continuity between any two parts, in particular any two neighbouring parts, of a one piece or monobloc fluid component or part according to the invention. A one piece or monobloc fluid component or part obtained by a process according to the invention is made of layers, stacked upon one another and contacting each other, each having a thickness of between <NUM> and <NUM> or <NUM>. Thicker layers may generate a higher surface roughness.

A process according to the invention may comprise an additive manufacturing of a block or piece of material, including the duct(s) and possibly the fluid connection area(s), so that the manufactured fluid component comprises one or more duct(s) in which is embedded in a block or piece of material. Alternatively, the wall(s) of the duct(s) are manufactured, at least part of said wall(s) having a thickness comprised between <NUM> and <NUM> with no material beyond said wall: this saves material between the ducts and allows the component to be much lighter.

In a CIJ printer, or a fluid component or a process according to the invention, a duct preferably has circular cross-section (perpendicularly to a flow of fluid inside said duct), having a diameter between <NUM> and <NUM>, for example between <NUM> and <NUM> or between <NUM>,<NUM> and <NUM>.

In a CIJ printer, or a fluid component or a process according to the invention, said at least one fluid connection area or surface can be a side or a surface or an interface against which another fluid component can be positioned and/or bear and be possibly fixed by securing means, so that:.

In a CIJ printer, or a fluid component or a process according to the invention, one or more of said fluid connection area(s) or surface(s) can have a roughness Ra (or arithmetical mean roughness) of less than <NUM> or less than <NUM> or less than <NUM> or less than <NUM>,<NUM>.

In a CIJ printer, or a fluid component or a process according to the invention, at least part of the inner or inside wall(s) of at least one duct(s), which is in contact with ink, is preferably as smooth as possible, the roughness Ra (or arithmetical mean roughness) of said inner or inside wall(s) being preferably less than <NUM>, or less than <NUM>, more preferably between <NUM> and <NUM>,<NUM>. Thus, pigments of ink cannot remain attached to the inner surface of the conduct, where they could form residual solid growth on the ink flow.

If said fluidic component or part comprises at least <NUM> ducts, they may extend at least partly along non parallel directions, in a same or in different planes.

A fluidic component according to the invention or a fluidic component in a CIJ printer according to the invention can be assembled with or to at least another fluid component, for example with one or more screw(s), or nut(s), or bolt(s), or clip(s), or clamp(s) or hook(s) or any other securing means.

The invention also concerns a process for printing, implementing a CIJ printer according to the invention. In particular such printing process may implement a pigmented ink.

A first example of a fluid component or part according to the invention is a fluid manifold <NUM> and is illustrated on <FIG>, <FIG>.

It comprises several conduits or ducts <NUM>, <NUM>, <NUM>, <NUM>, <NUM>; one or more of them can be for circulating either ink and/or solvent; as can be understood from these figures, several ducts may not extend in a same direction and/or in a same plane; in particular, as can be seen on <FIG>, some ducts <NUM>, <NUM> are not parallel with each other and/or may even intersect with each other; some of them may comprise a first portion <NUM> and a second portion <NUM> which are not aligned with each other along a straight direction.

Each duct has at least one end forming one or more fluid inlet and/or at least one end forming one or more fluid outlet <NUM>, <NUM>, <NUM>, <NUM>; one or more of said fluid inlet(s) and/or fluid outlet(s) can be adapted to connect one or more of said ducts, for example one or more of said fluid inlet(s) and/or fluid outlet(s) can have the shape of a fir-tree connection which can be introduced into another duct, for example a flexible duct. The fluid manifold <NUM> comprises one or more end parts or pieces 38a, 40a, 42a which comprise one or more fluid connection area(s) or surface(s) <NUM>, <NUM> (see <FIG>), <NUM> (see <FIG>) to connect the manifold to one or more other part(s) of an ink supply circuit and/or to one or more fluid components, for example at least one valve or at least one pump or at least one filter or at least one damper or at least one connection means like a cannula (for example cannula <NUM> or <NUM> of <FIG>). Each of said other fluid component comprises at least one fluid inlet and at least one fluid outlet, the component being positioned against one of the fluid connection areas of component <NUM> so that a fluid can flow from said other fluid component to said fluid manifold <NUM> or vice versa. Said end parts also contribute to the rigidity of the whole manifold.

Some ducts may be mechanically connected together by connecting means <NUM> (see <FIG>), comprising for example one or more connecting link(s) or beam(s) or wall(s) which extend(s) from one of said duct(s) to another one of said duct(s). This contributes to the rigidity of the whole manifold and avoids deformations of the fluid component <NUM> during use.

One or more duct may be straight; one or more duct may have a curvature radius of at least <NUM> in a plane containing the fluid flow direction or the fluid path or containing a tangent to said fluid flow direction or to said path, which offers several advantages as explained below.

One or more duct may have an inner diameter of between <NUM> and <NUM>, for example between <NUM> and <NUM> or between <NUM>, <NUM> and <NUM>. In the embodiment illustrated on <FIG>, 3E, the thickness of the wall of each duct is between <NUM> and <NUM>, for example between <NUM> and <NUM>, depending on the material of the component (for example plastic or metal) and on the required mechanical rigidity of the component.

One or more duct(s) can be for circulating ink, which comprises solvent but also pigments and binders. The inner or inside wall(s) of said duct(s), which is/are in contact with ink, is/are preferably as smooth as possible, the roughness of said inner or inside wall(s) being preferably less than <NUM>, or less than <NUM>, more preferably between <NUM> and <NUM>,<NUM>. Thus, pigments of ink cannot remain attached to the inner surface of the conduct, where they could form residual solid growth on the ink flow.

Preferably, said one or more fluid connection area(s) or surface(s) <NUM>, <NUM> (see <FIG>), <NUM> (see <FIG>) is smooth enough so that sealing means, for example a gasket, can be applied and pressed against it to form a leak tight assembly with said other fluid component or element; this means that this area preferably has a roughness less than <NUM> or less than <NUM>.

<FIG> and <FIG> are cross sections of a device according to the invention and of the same device made with known techniques.

Due to the known manufacturing process (<FIG>), the ducts cross each other at right or sharp angles which creates sharp edges <NUM>, <NUM>' where ink or ink pigments can deposit and form residual solid growth on the ink flow. Removing such deposits is difficult and requires stopping printing operations and cleaning the circuit with fluid. Furthermore, such angles result in pressure losses.

Preferably one or more of the ducts of a manifold according to the invention (<FIG>) has curved segments or sections <NUM>, <NUM>, <NUM>, thus avoiding sharp angles and the above-mentioned problems. Such curved segments or sections <NUM>, <NUM>, <NUM> have a non-zero but finite radius of curvature, in at least one plane which contains the direction of flow or a tangent to the flow; they allow a flow of liquid without pressure loss due to sharp angles. Preferably none of the ducts of a manifold according to the invention has sharp angles. Curved segments or sections <NUM>, <NUM>, <NUM> allow more ducts to intersect, because of the absence of sharp edges, and thus contribute to a compact device, with less pressure losses and no possibility for ink or ink pigments to form residual solid growth on the ink flow.

The manifold may further comprise sections having larger diameters, for example a chamber such as chamber <NUM> or chamber <NUM> (both described below), to form for example a sensor chamber (chamber <NUM>) or a pressure regulator or damping section (chamber <NUM>). In an ink jet printer, pressure variations may be due for example to pump cycles which are preferably limited or damped by a damping section.

It can comprise one or more chamber(s) <NUM> for a sensor, for example a pressure sensor <NUM> (see <FIG>). Fluid flows from one of the ducts or one or more of the holes 401a-c (hole 401b in this example) into said chamber and then flows out of said chamber through another duct (duct <NUM> in this example).

The manifold may comprise ducts for a fluid to flow into one of said chamber(s) <NUM> and fluid to flow out of said chamber, for example after a measurement by a sensor in said chamber.

It may also have one or more duct(s) for a fluid to flow directly from one fluid connection area to another fluid connection area, or from one fluid connection area directly to a duct outlet or from a duct inlet directly to a fluid connection area, said fluid not flowing through a chamber <NUM> or through a valve. This is the case for ducts connecting different parts of an ink circuit, whereby the fluid component or the manifold is used as a fluid connection between said different parts (see also below explanation in reference to <FIG>).

For example, inlet <NUM> (resp. <NUM>) is directly connected to outlet <NUM> in fluid connection area <NUM> (resp. <NUM>, see also <FIG>).

The manifold illustrated on <FIG> comprises several fluid inlets and several outlets. Each fluid connection area or surface <NUM>, <NUM>, <NUM> comprises at least one of said fluid inlets and outlets.

In this example each of said fluid connection area may comprise one or more opening(s) forming fluid inlet(s) or outlet(s) 401a, 401b, 401c (see also 402a and 402b on <FIG>) and one or more holes <NUM>, <NUM> (see <FIG>) for fixing or securing a valve against said connection area <NUM>, <NUM>, <NUM>. The area <NUM>, <NUM>, <NUM> itself is preferably smooth enough so that sealing means, for example a gasket, can be applied against it. For example, it can have a roughness less than <NUM> or less than <NUM> or less than <NUM>, for example <NUM>,<NUM>. This can result from the manufacturing process explained below (3D printing process); but the fluid manifold can be subject to a further processing step after 3D printing, it is for example machined or polished or smoothed or grinded, in order to reach the required roughness and/or it is subject to a chemical process (see below).

In an embodiment, sealing means, for example a gasket, are made integrally with the rest of the manifold. Said sealing means can be made for example in a compressible material. Two different materials can be 3D printed, for example with two different nozzles.

Several ducts may connect to a same end piece which thus forms a mechanical link between said ducts; for example, ducts <NUM>, <NUM> are connected to end piece 42a which maintains their ends. Both ducts <NUM>, <NUM> are also connected with means <NUM> and their other ends are connected to chamber <NUM>.

<FIG> is a schematic representation of the fluid flow inside the manifold <NUM> of <FIG>. The inlets, outlets, ducts bear the reference numerals of <FIG>.

A valve <NUM> is applied against contact area <NUM> (<FIG>) and sensor <NUM> is located in chamber <NUM> (see <FIG>). It allows a fluid to flow from inlet 402b (see <FIG>) to either outlet 401a or 401c or from inlet 401a or 401c to outlet 402b (depending on the position of the valve and on the flow direction).

As can be understood from this figure one or more duct(s) are for a fluid to flow directly from one fluid connection area to another fluid connection area, or from one fluid connection area directly to a duct outlet or from a duct inlet directly to a fluid connection area, said fluid not flowing through a chamber <NUM> or through a valve. This is the case for ducts connecting inlet <NUM> and outlet <NUM>, or inlet <NUM> and outlet <NUM>: the fluid component or the manifold <NUM> is thus also used as a fluid connection between different parts of the printer in which it is incorporated. The manifold <NUM> can be used in a continuous ink jet printer, for example as illustrated on <FIG>: a sensor <NUM> is housed in chamber <NUM> and a <NUM>-way valve <NUM> is fixed against fluid connection area <NUM> of manifold <NUM>.

The manifold illustrated on <FIG> comprises several fluid connection areas or surfaces <NUM>, <NUM>, <NUM>. Each extends in a different plane than the <NUM> others, thus allowing a connection of the manifold on each area to a different part or component of a printer, as illustrated on <FIG> where the manifold also bears the reference <NUM>.

For example, the several fluid connection areas or surfaces <NUM>, <NUM>, <NUM> allow connections to valve <NUM> (area <NUM>, <FIG>) and to other portions of the ink circuit, for example to a fluid recovery module <NUM> (see description of <FIG> below), to part of a fluid circuit (see the connections to ducts <NUM>, <NUM> on <FIG>), and to the ducts connecting to the printing head <NUM>.

The end <NUM>, <NUM>, <NUM>, <NUM> of one or more ducts can be configured for a connection to flexible ducts or hoses and thus can be shaped as fir tree connections.

A fir tree connection is made of a tube with a diameter slightly higher than that of inside the hose to which it must connect, this tube being equipped with concentric barbs having a low angle in the insertion direction of the hose (the flexibility of the hose allows an easy insertion) and a sharp angle in the extraction direction (the hose is thereby retained during an extraction).

A fir tree connection may be machined (for example by a milling process) from a cylinder of material deposited by 3D printing (see further explanations below) or may be directly manufactured by 3D printing.

A manifold, or more generally a fluid component, according to the invention is or comprises one single block or a single piece made in a single material, for example stainless steel, with no interface between different pieces and different materials. There are thus no leak problems at such interfaces.

In an embodiment, the ducts of the component of <FIG> can be embedded in a single piece or block of material.

In another embodiment, illustrated on <FIG> the component or manifold is topologically optimised because there is no useless matter between ducts: only the functional parts are manufactured. In such case, the ducts walls have for example a thickness of between <NUM> and <NUM>, or between <NUM> and <NUM>, which saves all the material which is normally between the ducts. The thickness of the wall of the ducts can be selected depending on the material and the required rigidity of the component, in particular with respect to the fluid pressure (for example up to <NUM> bars).

A manifold or, more generally, a fluid component according to this embodiment of the invention can thus save a lot of material and be much lighter than a known manifold or fluid component. In a variant, the manifold, or fluid component can comprise material between the ducts, like in the embodiment of <FIG>, in which case it still one single piece or block but is heavier than the embodiment of <FIG>.

Another example of a fluid component <NUM> according to the invention is illustrated on <FIG>.

It comprises a body which has a front side <NUM> and a back side <NUM> parallel with each other; the thickness e (for example between <NUM> and <NUM>) of the body is preferably small compared to the width W (for example between <NUM> and <NUM>) and the height H of the front and back sides.

The body contains a plurality of conduits or ducts <NUM>, <NUM>, <NUM> which extend parallel to the front and the back sides <NUM>, <NUM>. Some of said ducts may not extend in a same direction: as can be seen on <FIG>, some ducts <NUM>, <NUM> are not parallel with each other; some of them may comprise a first portion <NUM> and a second portion <NUM> with are not aligned with each other along a straight direction.

One or more conduit(s) or duct(s) may have an inner diameter of between <NUM> and <NUM>, for example between <NUM> and <NUM> or between <NUM>,<NUM> and <NUM>.

Some conduits or ducts <NUM>, <NUM>, <NUM> can be connected via further inside ducts 52a, 52b, 54a, 54b, 56a, 56b to fluid inlet(s) or outlet(s) <NUM>, <NUM>, <NUM> located for example on a fluid connection area <NUM> which is perpendicular to both front and the back sides <NUM>, <NUM>. Said fluid inlet(s) or outlet(s) <NUM>, <NUM>, <NUM> can be provided with counterbores 62a, 64a, 66a for gaskets.

Some conduits or ducts <NUM>, <NUM>, <NUM> can be connected to inlet(s) or outlet(s) located in another fluid connection area, for example the back side <NUM> (see <FIG>), via further inside ducts (not represented on the figure), essentially perpendicular to said other fluid connection area <NUM>. Said fluid connection area <NUM> is provided with fluid inlet(s) and outlet(s) <NUM>, <NUM>, <NUM>, <NUM>, <NUM> to connect one or more fluid components with said conduits or ducts <NUM>, <NUM>, <NUM> of the manifold, said component comprising for example one or more valve(s) and/or one or more pumps. Other holes <NUM> can be provided to fix and secure such components with the manifold, for example with screws.

The ducts <NUM>, <NUM>, <NUM> of the device <NUM> illustrated on figured 4A and 4B are embedded in the material of the body which surrounds them and which is deposited during an additive manufacturing process.

Alternatively, the same ducts can be made as in the device of <FIG>, 3E, no material joining the walls of the ducts, in which case there are no complete front and back parallel sides, but fluid connection areas formed by end pieces such as illustrated on <FIG>, thin walls or connecting members linking and connecting the ducts where necessary to achieve the required mechanical stability. This embodiment also allows more flexibility, allowing the shape and/or the proportions of the component to be varied with respect to the original shape like the one illustrated on <FIG>. In this embodiment, the thickness of the wall of each duct is between <NUM> and <NUM>, for example between <NUM> and <NUM>, depending on the material of the component (for example plastic or metal) and on the required mechanical rigidity of the component, in particular with respect to the fluid pressure (for example up to <NUM> bars).

One or more of the ducts of the manifold illustrated on figured 4A and 4B may be straight while one or more of the ducts of this manifold can have curved segments or sections <NUM>, <NUM>, thus avoiding sharp angles and the above-mentioned problems. Such curved segments or sections <NUM>, <NUM> have a non-zero, but finite, radius of curvature, for example at least <NUM>, in at least one plane which contains the direction of flow or a tangent to the flow; they allow a flow of liquid without pressure loss due to sharp angles. Preferably none of the ducts of a manifold according to the invention has sharp angles. Curved segments or sections allow more ducts to intersect, because of the absence of sharp edges, and thus contribute to a compact device, with less pressure losses and no possibility for ink or ink pigments to form residual solid growth on the ink flow.

Further fluid connectors can be connected to some ducts of the device <NUM>, for example connectors <NUM>, <NUM> comprising one or more cannula to plug cartridges. On the example of <FIG>, said connectors <NUM>, <NUM> are connected to the front side <NUM> of the device but may not be manufactured by the same 3D printing process as the manifold. Said connectors <NUM>, <NUM> are for connecting fluid cartridges, in particular a solvent cartridge and an ink cartridge of CIJ printer, for example as illustrated on, <FIG>.

The manifold <NUM> illustrated on figured 4A and 4B can comprise further components, for example a chamber or a cavity <NUM> for a damper, said cavity being connected to one or more of the inside ducts of the device by a duct 72a.

<FIG> is a schematic representation of the manifold of <FIG>. The inlets, outlets, ducts bear the reference numerals of <FIG>.

Several <NUM>-way valves <NUM><NUM>-<NUM><NUM>, <NUM> are applied against contact area <NUM> (see <FIG> and <FIG>). <NUM> pumps <NUM>, <NUM> can be connected to said valves, in order to pump ink, respectively solvent, from ink cartridge <NUM> and from solvent cartridge <NUM>. Ink flows from ink cartridge <NUM> connected to connector <NUM>, then to valve <NUM><NUM>; <NUM><NUM> corresponds to the outlet in the middle of valve <NUM><NUM>; <NUM><NUM>corresponds to an end of conduit <NUM><NUM> to circulate the ink towards the pump <NUM>.

Preferably, said fluid connection areas or surfaces <NUM>, <NUM> (see <FIG>) are smooth enough so that sealing means, for example a gasket, can be applied and pressed against it to form a leak tight assembly with another fluid component or element, for example a <NUM>-way valve; this means that this area preferably has a roughness less than <NUM> or even less than <NUM>.

As already explained in connection with <FIG>, some ducts are for circulating ink, which comprises solvent but also pigments and binders. The inside walls, which are in contact with ink, are preferably as smooth as possible, their roughness being preferably less than <NUM>, or less than <NUM>, more preferably between <NUM> and <NUM>,<NUM>. Thus, pigments of ink cannot remain attached to the inner surface of the conduct, where they could form residual solid growth on the ink flow.

The manifold <NUM> can be used in a continuous ink jet printer, for example as illustrated on <FIG>.

Another example of a fluid component <NUM> according to the invention is a hydraulic distributor and is illustrated on <FIG>; further embodiments being illustrated on <FIG>.

A first example of an embodiment of this hydraulic distributor according to the invention is illustrated on <FIG>.

When the device is assembled, both flat surfaces <NUM>, <NUM> are in friction contact with each other: they can be rotated relative to each other but remain in contact during the rotation. No fluid can flow out of the device between both surfaces: the contact at the interface between both surfaces is watertight. A device according to the invention does not require any gasket.

Flat surface <NUM> is a fluid connection area and comprises one fluid inlet <NUM><NUM> and one fluid outlet <NUM><NUM>. As can be seen on <FIG>, a first duct 112a extends between the inlet <NUM><NUM> and the inlet to said inner channel <NUM> and a second duct 112b extends between the outlet said inner channel <NUM> and the outlet <NUM><NUM>.

These different ducts are connected together by the material deposited during an additive process.

Means <NUM> (<FIG>), such as a spring, can be used to press both surfaces against each other. The first portion rests for example on a support <NUM> (<FIG>) on which it can be maintained in a fixed position; each of the first portion and the support can comprise means <NUM> (<FIG>), <NUM> (<FIG>) which cooperate with each other to keep the first portion in a fixed position.

In this example both portions <NUM>, <NUM> have a cylindrical shape, but other shapes are possible, as described below in connection with <FIG>.

In an embodiment, the hydraulic distributor comprises a shaft <NUM> which extends along an axis of rotation to rotate portion <NUM> with respect to portion <NUM>.

A handle <NUM> is represented on <FIG> to manually control said shaft. Alternatively, said shaft can be controlled by a motor (as explained below in connection with <FIG>), which itself can be controlled by the controller of a printer.

A cover <NUM> can cover the two portions (<FIG>): one end of the shaft <NUM> rises above the top surface of the cover so that it can be connected to a handle <NUM> or to any transmission mechanism from a motor.

<FIG> show a variant of a hydraulic distributor <NUM>' according to the invention. Like on <FIG>:.

In this embodiment, the surface <NUM>' of the second portion opposed to surface <NUM> comprises several holes <NUM> which can accommodate studs of a tool or of a driving section (see <FIG>), to rotate the second portion <NUM> with respect to the first portion <NUM>. Thus, a central shaft which traverses through the second portion is not needed.

Both first and second portions can be guided in rotation in a guiding cylinder <NUM>, as illustrated on <FIG>, fluid entering the distributor through one (<NUM><NUM>) of said ducts <NUM>, then flowing in said channel <NUM> and leaving the distributor through another one (<NUM><NUM>) of said ducts <NUM>.

Another example of portions guided in rotation is illustrated on <FIG> and commented below.

As illustrated on <FIG>, the hydraulic distributor of <FIG> can be inserted in guiding cylinder <NUM>, which guides both portions <NUM>, <NUM> with respect to each other, portion <NUM> being maintained fixed with help of means (like means <NUM>, <NUM> described above) not illustrated on the figure.

The arrows of <FIG> show how the fluid flows into the distributor through duct <NUM><NUM>, then flows through inlet <NUM><NUM>, and in or through the duct 112a, the channel <NUM>, the duct 112b and flows out of the distributor flows through outlet <NUM><NUM> and through duct106<NUM>. In a variant (not represented on <FIG>), the portion <NUM> has three through ducts, which are connected together in a certain relative position of both portions <NUM>, <NUM>.

<FIG> and <FIG> show surface <NUM> of the first portion (which comprises three through ducts <NUM><NUM> - <NUM><NUM>) and surface <NUM> of the second portion (which comprises inlet <NUM><NUM> and outlet <NUM><NUM> and to which channel <NUM> is parallel); as illustrated on <FIG> and <FIG> (on which hole <NUM> is not represented):.

In any embodiment of a hydraulic distributor according to the invention, a spring <NUM> can be used to press said first portion <NUM> against said second portion <NUM>.

<FIG> shows a simpler example of a hydraulic distributor (actually a hydraulic shutter) according to the invention, the first portion <NUM> comprising two through ducts <NUM><NUM>, <NUM><NUM> and the <NUM>nd portion <NUM> having one channel <NUM>. In a first position of the <NUM>nd portion, the channel <NUM> connects both ducts <NUM><NUM>, <NUM><NUM> and the fluid can circulate from one of said ducts to the other one. In a second position (not represented) of the <NUM>nd portion, the channel <NUM> does not connect ducts <NUM><NUM>, <NUM><NUM> together and the fluid circulation is stopped.

<FIG> show another example of a hydraulic distributor <NUM>" according to the invention, the first portion <NUM> comprising <NUM> through ducts <NUM><NUM> - <NUM><NUM> and the <NUM>nd portion <NUM> having <NUM> channels <NUM><NUM>, <NUM><NUM>.

<FIG> (resp. 11A, 12A, 13A) shows the surface <NUM>' of the second portion <NUM> opposed to surface <NUM>; this surface <NUM>' can comprise several holes <NUM> as explained above to drive the second portion with respect to the first portion.

<FIG> (resp. 11B, 12B, 13B) shows the surface <NUM> of the second portion <NUM> which comprises the <NUM> channels <NUM><NUM>, <NUM><NUM>.

<NUM> different relative positions of the both portions are illustrated on <FIG> to connect different pairs or series of through ducts <NUM><NUM> - <NUM><NUM>; <FIG>, <FIG> show the different positions of the <NUM> channels <NUM><NUM>, <NUM><NUM> and the projection on surface <NUM> of the positions of the ducts <NUM><NUM> - <NUM><NUM>:.

The above example of <FIG>, and those of <FIG> and 12A-B, shows that, in one or more relative position(s) of both portions, a hydraulic distributor according to the invention can connect more than two ducts together.

A linear hydraulic distributor <NUM> according to the invention is disclosed in connection with <FIG>; like the circular device disclosed above, it can have any number of through ducts <NUM>, and any number of appropriate channels to establish the required connections between the through ducts in the different relative positions of the two portions <NUM>, <NUM>.

As illustrated on <FIG>, a linear hydraulic distributor <NUM> according to the invention implements a relative translation of the <NUM> portions rather than a rotation.

Both portions can be maintained by lateral guiding walls <NUM> guiding the translation of one portion of said hydraulic distributor with respect to the other; this translation can be actuated by an actuating link or a button or by a motor, for example an electric or hydraulic or pneumatic motor, coupled to one of the portions <NUM>, <NUM>.

A spring can be used between one of the guiding walls, parallel to the direction of the translation to press said both portions of said hydraulic distributor against each other.

In the above examples, one or more inner channel(s) <NUM>, <NUM><NUM>, <NUM><NUM>, <NUM><NUM>-<NUM><NUM> extend(s) parallel to the surface <NUM> and is/are made inside said <NUM>nd portion (it does not appear in the surface <NUM> of said <NUM>nd portion).

Said one or more inner channel(s) in a distributor <NUM>, <NUM>', <NUM>", <NUM> according to the invention offer(s) the advantage of avoiding any edge on the surface which is in contact with surface <NUM> of the <NUM>st portion <NUM> of the device; indeed, dirt and/or ink can be deposited at these edges and dry, which can pose problems of tightness of both contacting surfaces <NUM>, <NUM>. And an inside channel can be cleaned by a flow of solvent.

In the above examples, any of the ducts <NUM>, <NUM><NUM>-<NUM><NUM>, <NUM>, <NUM><NUM>-<NUM><NUM> and/or of the channel(s) <NUM>, <NUM><NUM>-<NUM><NUM>, <NUM><NUM>-<NUM><NUM> can have a diameter of up to <NUM> or more, allowing important flow rates, up to <NUM>/h or <NUM>/h or even more, for example <NUM>/h or <NUM> I/h. Some solenoid valves are compatible with such flow rates, but they are bulky, heavy and expensive.

In the above examples, the second portion <NUM> of the device comprises at least one inside channel in which a fluid can flow parallel to surface <NUM> or <NUM>'.

Assembling steps of a hydraulic distributor according to the invention with a body or manifold <NUM> are illustrated on <FIG>.

A driving section <NUM> has <NUM> parallel surfaces <NUM>' and <NUM>". It comprises studs <NUM> distributed on one of said surface <NUM>' to penetrate into holes <NUM> of second section <NUM>.

The other main surface <NUM>" of said driving section <NUM> comprises a drive shaft <NUM>.

A pressure spring <NUM> presses on the driving section of the hydraulic distributor when the device is assembled and accommodated in a hole <NUM> of a body or manifold <NUM> (<FIG>), said spring being compressed between said driving section <NUM> and an end plate <NUM> of the body <NUM> which closes the hole <NUM>. The driving shaft <NUM> traverses the plate <NUM> through a central hole <NUM>h. A motor (not illustrated on the figure), for example an electric or hydraulic or pneumatic motor, can drive the shaft <NUM>, and the second portion <NUM>, in rotation, to change the position of the channel <NUM> with respect to the first portion, thus varying the fluid communication of the distributor, for example as illustrated on <FIG> and <FIG>.

As can be understood from the above description, a hydraulic distributor according to the invention, in particular for an ink-jet printer, can comprise:.

It can also comprise means <NUM>, <NUM> for moving both portions with respect to each other, so that:.

Said means, for example a motor, for moving both portions of said hydraulic distributor with respect to each other can allow a movement:.

In both the circular and the translation embodiments, means, for example a spring, can be used for pressing said <NUM>st planar surface and said <NUM>nd planar surface against each other.

Said <NUM>st portion can for example comprise n conducts, for example at least <NUM> or <NUM> conducts, each comprising an opening in said <NUM>st planar surface; for n=<NUM>, the at least one channel in said 2nd portion can connect, in the first position with respect to the <NUM>st portion, a first pair of said at least <NUM> conducts and, in a second position with respect to the <NUM>st portion, another pair of said at least <NUM> conducts.

Said <NUM>nd portion can comprise a plurality of channels extending parallel to said <NUM>nd planar surface, to conduct a fluid in at least two different directions substantially parallel to said <NUM>nd planar surface.

A method for operating a hydraulic distributor according to the invention can comprise moving both portions with respect to each other between said first position and said second position, so that:.

A hydraulic distributor according to the invention is adapted to a printer comprising a single-nozzle or a multi-nozzle ink jet print head, as represented on <FIG> and <FIG> of <CIT>.

A hydraulic distributor according to the invention can be implemented in any part of a fluid circuit of a CIJ printer, for example the CIJ printer illustrated on <FIG> and commented below, to replace any known valve, in particular any solenoid valve.

In particular a hydraulic distributor according to the invention can be positioned upstream of any pump (for example pump <NUM> of <FIG>) which pumps ink or solvent from an ink tank <NUM> or from an ink cartridge <NUM> or from a solvent tank or cartridge <NUM> and which is to be sent to a main tank or to a print head <NUM> of a CIJ printer.

Alternatively, it can be positioned downstream of any pump which pumps ink or solvent, with a pressure of fluid circulating in said pump of up to several bars, for example <NUM> or <NUM> bars.

A hydraulic distributor according to the invention can be operated so as to guide a flow of fluid, for example ink and/or solvent of an ink jet printer:.

The fluid flow rate can be comprised between <NUM>/h or <NUM> I/h and <NUM>/h or <NUM>/h or even more, for example <NUM>/h or <NUM> I/h.

The pressure of fluid circulating in a hydraulic distributor according to the invention can be higher than <NUM> or <NUM> bars, and up to several bars, for example less than <NUM> or <NUM> bars or even <NUM> bars.

Said fluid can be pumped by a pump of an ink circuit of a CIJ printer.

Portion <NUM>, <NUM> of a hydraulic distributor according to the invention is manufactured by a process according to the invention. Portion <NUM>, <NUM> can be manufactured by a process according to the invention.

Flat surface <NUM>, <NUM> is a fluid connection area and comprises one fluid inlet <NUM><NUM> and one fluid outlet <NUM><NUM>. As can be seen on <FIG>, a first duct 112A extends between the inlet <NUM><NUM> and the inlet to said inner channel <NUM>, <NUM> and a second duct 112b extends between the outlet said inner channel <NUM> and the outlet <NUM><NUM>.

As explained below, a manufacturing process of at least portion <NUM>, <NUM> of a hydraulic distributor according to the invention can comprise a 3D printing process.

If a desired roughness is not obtained by the 3D printing process, a further smoothing step (mechanical and/or chemical) can be implemented.

The body or manifold <NUM> illustrated on <FIG> can itself be manufactured according to the invention. It is illustrated on <FIG> and a schematic representation of the fluid flows through said body or manifold is illustrated on <FIG>.

The hydraulic distributor, for example, a rotating distributor according to any of <FIG> (not represented on these <FIG>) can connect a fluid inlet <NUM>, resp. <NUM>, to a fluid outlet <NUM> through outlet <NUM>, resp. Each of the <NUM> inlets <NUM>, <NUM>, <NUM> corresponds to one of the outlets <NUM> (see <FIG>), the duct <NUM> connecting two of these outlets <NUM> to two of said <NUM> inlets, depending on the position of the second portion <NUM>.

A fluid inlet <NUM>' is connected to a fluid outlet <NUM> because it is more convenient to have a through duct in the body <NUM> than to connect the corresponding inlet/outlet of the ink circuit by a flexible duct.

Body <NUM> is represented here for <NUM> inlets <NUM>-<NUM>. In a variant, body <NUM> has <NUM> inlets on surface <NUM> or more than <NUM> inlets, which are connected to appropriate ducts inside the body <NUM> and to corresponding outlets.

Due to its elongated shape along a ZZ' axis, this body can connect one or more fluid inlet(s) located on surface <NUM>, which is substantially perpendicular to said axis, to an outlet located laterally, for example on a face or a side <NUM>' of the device which is substantially parallel to said axis. One or more in conduits of said body can have curved shape, to guide the flow of fluid from a direction substantially parallel, respectively perpendicular, to a direction substantially perpendicular, respectfully parallel, to said axis ZZ'.

The body <NUM> is manufactured by an additive process as explained below.

The second portion of a hydraulic distributor according to any of <FIG> is applied against contact surface <NUM>, which has a roughness preferably less than <NUM>, more preferably less than <NUM>. Preferably, each of the ducts connecting an inlet and an outlet of this body <NUM> has an inner roughness of less than <NUM>.

The body or distributor <NUM> comprises several fluid connection areas or surfaces <NUM>, <NUM>' etc which extend in different planes, thus allowing a connection of the body or manifold on each area to a different part or component of an ink circuit of a CIJ printer, for example the one illustrated on <FIG>.

For example, the several fluid connection areas or surfaces <NUM>, <NUM>' allow connections to hydraulic distributor <NUM> and to other portions of the ink circuit, for example to a pump module <NUM> (see description of <FIG> below), to part of a fluid circuit (see the connections to ducts <NUM>, <NUM> on <FIG>), and to another module <NUM> (described below).

If a desired roughness is not obtained by the 3D printing process (see below), a further smoothing step (mechanical and/or chemical) can be implemented as explained below.

One or more of the ducts of the body or manifold <NUM> illustrated on figured 16A-<NUM> may be straight while one or more of the ducts of this manifold can have curved segments or sections, thus avoiding sharp angles and the above-mentioned problems. Such curved segments or sections have a non-zero radius of curvature, for example at least <NUM>, in at least one plane which contains the direction of flow or a tangent to the flow; they allow a flow of liquid without pressure loss due to sharp angles. Preferably none of the ducts of a body or manifold <NUM> according to the invention has sharp angles. Curved segments or sections allow more ducts to intersect, because of the absence of sharp edges, and thus contribute to a compact device, with less pressure losses and no possibility for ink or ink pigments to form residual solid growth on the ink flow.

The ducts illustrated on figured 16A-<NUM> are embedded in a block or a piece of material forming the component or fluid manifold <NUM>. Alternatively, the component or fluid manifold <NUM> can be made as in the device of <FIG>, <FIG>, no material joining the walls of the ducts in which case there are no complete front and back parallel sides, but fluid connection areas formed by end pieces such as illustrated on <FIG>. One or more thin wall or connecting member (such as a beam or a link) can possibly link the ducts where necessary to achieve the required mechanical stability. In this embodiment, the thickness of the wall of each duct is between <NUM> and <NUM>, for example between <NUM> and <NUM>, depending on the material of the component (for example plastic or metal) and on the required mechanical rigidity of the component, in particular with respect to the fluid pressure (for example up to <NUM> bars).

The embodiments of this component with no material between at least two parts, for example two ducts, are particularly interesting because of the advantages associated to them, in particular the limited amount of raw material required for manufacturing them and the limited weight of the component, and also of the printer in which they are incorporated. As already explained above, there is no useless matter between the different parts and only the functional parts are manufactured, which saves all the material which is normally between the ducts.

A printing head of a CIJ printer can comprise one or more part(s) according to the invention.

An example of an embodiment of a printing head <NUM> according to the invention is illustrated on <FIG> and <FIG>.

It comprises a supporting base <NUM>, which incorporates a manifold according to the invention or in which said manifold is embedded.

Said supporting base can support one or more individual components like a solenoid valve unit <NUM>, an ink drop generating unit <NUM> and charge and deviation electrodes <NUM>. The ink drop generating unit <NUM> comprises a stimulation body and a nozzle through which the drops are ejected.

The solenoid valve unit <NUM> can be mounted on a solenoid valve support <NUM>. The ink drop generating unit and both charge and deviation electrodes can be mounted on a drop generator and electrodes support <NUM>. Both solenoid valve support <NUM> and drop generator and electrodes support <NUM> can be fixed or secured against an upper or front surface <NUM> of the supporting base <NUM> of the printing head, for example by screwing. They are both comprised between lateral edges 220a, 220b of the supporting base <NUM>. Alternatively, the supporting base <NUM> and the solenoid valve support <NUM> and/or the drop generator and electrodes support <NUM> form a single block (or a monolithic or integral structure) and are formed together by additive printing.

Usually, the head is covered by a hood (not represented on the figures) so that a user cannot easily access to the electrodes and high voltage portions.

The base <NUM> extends between said upper or front surface <NUM>, and a lower or back surface <NUM>. It comprises a network of fluid conduits for circulating the fluids (ink and/or solvent) to the ink drop generator and returning the fluids from the ink recovery gutter.

Said network comprises at least one or more conduits for circulating ink, one or more conduits for circulating solvent, and one or more conduits for circulating ink recovered from said print head back to the ink circuit of a CIJ printer.

As can be seen on <FIG>, base <NUM> comprises:.

The network of ducts can further comprise:.

<FIG> shows an assembly of the base <NUM> together with the supports <NUM> and <NUM>. References 226a-226d are openings corresponding to through holes of said base <NUM> at least for the recovery of ink from the gutter (opening 226a) and for injecting ink and solvent (226d) from conduit <NUM> into the ink drop generating unit <NUM>; openings can possibly be included for injecting air (226b) and/or for recovering ink (226c) from the ink drop generating unit <NUM> back to conduit <NUM>.

Through connectors 220a (<FIG>) are for the electric connections to supply the stimulation body, the charge electrodes and the deviation electrode(s).

Said supporting base <NUM> is manufactured according to the invention, by an additive manufacturing technique. In a particular embodiment, said base plate and said solenoid valve support body and/or drop generator body are manufactured by a same additive manufacturing technique, area <NUM> remaining a fluid connection area to connect the flexible supply cable of the printer to the print head.

The ducts of the network inside the base are in a same plane. The printing head, and in particular said ducts, can have one or more of the features already described above in connection with other embodiments. In particular:.

One or more of the ducts of the network of base <NUM> illustrated on figured <NUM> may be straight while one or more of the ducts of this manifold can have curved segments or sections, thus avoiding sharp angles and the above-mentioned problems. Such curved segments or sections have a non-zero radius of curvature, for example at least <NUM>, in the plane of the network which allows a flow of liquid without pressure loss due to sharp angles. Preferably none of said ducts has sharp angles. Curved segments or sections contribute to a compact device, with less pressure losses and no possibility for ink or ink pigments to form residual solid growth on the ink flow.

A printing head according to the invention can be used in combination with a CIJ printer, for example as illustrated on <FIG>.

As can be understood from the above description, a manifold according to the invention, in particular for a printing head of an ink-jet printer, can be be in, or can be embedded in, a base or a back wall of said printing head and comprising several ducts, for example:.

Said manifold can further comprise the features explained above in connection with <FIG>.

Another example of a fluid component according to the invention is a fluid connector <NUM>, illustrated on <FIG> and also explained in an application to a pump module <NUM> on <FIG>.

Each conduit can have a bend to guide a fluid as it flows from an inlet <NUM> (resp. <NUM>) to an outlet 322a (resp. 324a) of the connector; conduit <NUM> can be used to guide a fluid flowing from the fluid circuit of a CIJ printer into another fluid component of said fluid circuit, for example a pump, said fluid circulating from inlet <NUM> to the outlet 322a and then into the other fluid component ; conduit <NUM> can be used to guide a fluid flowing out of said other fluid component, for example said pump, said fluid circulating from an inlet <NUM> to the outlet 324a and then into the fluid circuit of a CIJ printer.

As can be seen on <FIG>, each inlet/outlet surface has one or more recess(es) to receive one or more sealing means, for example one or more gaskets.

Said fluid connector can further comprise one or more alignment member(s) <NUM> (for example one or more pin(s) or rod(s) or slug(s)) adapted to fit into corresponding slot(s) or hole(s) to position the connector with respect to a module in which it is integrated, for example as illustrated in <FIG> (in a variant the one or more alignment member(s) <NUM> are in the module and the corresponding slot(s) or hole(s) are in the connector).

The connector <NUM> and its conduits or ducts can have one or more of the features already described above in connection with other embodiments. In particular:.

One or more of the ducts <NUM>, <NUM> may be straight while one or more of said ducts of this manifold can have curved segments or sections, as shown on <FIG>, thus avoiding sharp angles and the above-mentioned problems. Such curved segments or sections have a non-zero radius of curvature, for example at least <NUM>, in the plane of the network which allows a flow of liquid without pressure loss due to sharp angles. Preferably none of said ducts has sharp angles. Curved segments or sections contribute to a compact device, with less pressure losses and no possibility for ink or ink pigments to form residual solid growth on the ink flow.

An example of a pump module (or ink pressure pump module) <NUM> is illustrated on <FIG>. It comprises a housing or support <NUM>, possibly including a front side or cover <NUM>; said module comprises a fluid inlet <NUM> and a fluid outlet <NUM>; inside the module or its housing, at least the hydraulic part <NUM> of a pump <NUM> is connected to said fluid inlet and said fluid outlet. As illustrated on <FIG>:.

The pump illustrated on <FIG> comprises a hydraulic part <NUM>, a motor <NUM> and an axis <NUM> coupling said hydraulic part <NUM> and said motor <NUM>; the pump can be of the magnetic type. Such a magnetic pump comprises a shell (part of which is referenced <NUM> on <FIG>) containing a hydraulic part, or impeller, coupled to a shaft which bears an inner magnetic ring; outside the shell, an outer magnetic ring is mounted on a drive shaft and is magnetically coupled to the inner magnetic ring through the shell. A motor can drive the drive shaft and the outer magnetic ring in rotation; in turn, the outer magnetic ring drives the inner magnetic ring, and the impeller, in rotation because of the magnetic coupling. In case of a magnetic pump, the axis <NUM> of <FIG> is the drive shaft, the impeller and its shaft being housed in the housing <NUM>.

The ink circuit of a CIJ printer (for example the CIJ printer of <FIG>) can have a receiving portion or zone or interface to receive the pump module and connect it to the hydraulic circuit of the printer. Said receiving portion or zone or interface has at least one fluid inlet (s) which corresponds to the fluid outlet <NUM> and at least one fluid outlet which corresponds to the fluid inlet <NUM> of said pump single-block assembly, so that fluid can flow from said interface outlet into said first single-block assembly and then out of said first single-block assembly to said interface inlet.

<FIG> show an embodiment of a pump module (or ink pressure pump module) <NUM>, in which the motor <NUM> of the pump <NUM> is located outside the pump module. The hydraulic part <NUM> of the pump is maintained between front cover <NUM> and a back cover <NUM>' which can be demountable as can be seen on <FIG>. The hydraulic part <NUM> of the pump can be easily removed after back cover <NUM>' is demounted. Reference <NUM> is for example the outer magnetic part of the pump, it is located outside of the housing <NUM>.

As seen on <FIG> the back side of the housing of the pump module is not completely closed so that the pump <NUM> (or the part of the pump contained in the housing <NUM>) can be cooled by air of the surrounding atmosphere.

The housing can be provided with slots or openings <NUM> to facilitate air circulation around the pump.

The ink circuit has a receiving portion or zone or interface to receive the module, which can be mounted on and disassembled from said receiving portion or zone or interface, for example with one or more screw(s), or nut(s), or bolt(s), or clip(s), or clamp(s) or hook(s) or any other securing means. Hole <NUM><NUM>, <NUM><NUM>, <NUM><NUM> are visible on <FIG> to accommodate screws <NUM><NUM>, <NUM><NUM>, <NUM><NUM>, one screw head <NUM>'<NUM> being visible on <FIG>.

As can be understood from <FIG>, a fluid connector <NUM>, illustrated on <FIG>, can be used to connect the inlet/outlet <NUM>/<NUM> of the pump of <FIG> to the inlet/outlet <NUM>/<NUM> of the housing.

The pump module <NUM> can be used in a continuous ink jet printer, for example as illustrated on <FIG>.

Another example of a fluid component according to the invention is a stimulation body <NUM> and is illustrated on <FIG>.

This stimulation body can be used in combination with a piezoelectric component or actuator to generate ink drops or jets.

It comprises <NUM> lateral walls <NUM>, <NUM>, a back wall <NUM> and a bottom wall <NUM>.

The bottom wall comprises a recess <NUM> to receive a piezoelectric component or actuator (not represented on the figure).

The stimulation body of this example comprises several ducts <NUM>, <NUM>, <NUM>, <NUM> in which a fluid can circulate from a fluid supply network to a stimulation chamber <NUM> and from said stimulation chamber back to said fluid supply network. The fluid flow is represented by arrows on <FIG>. Ducts <NUM>, <NUM> are in the bottom wall <NUM> or can protrude from said wall.

The outside surface of the back wall <NUM> forms a fluid connection surface comprising <NUM> holes <NUM>, <NUM> through which the fluid can flow and which can be connected to a fluid manifold, for example of the type disclosed above in connection with <FIG>.

The stimulation body <NUM> can be used in an ink drop generating unit <NUM> of a printing head <NUM> as disclosed in connection with <FIG>.

The stimulation body <NUM>, including its conduits or ducts, can have one or more of the features already described above in connection with other embodiments. In particular:.

One or more of the ducts <NUM>, <NUM>, <NUM>, <NUM> may be straight while one or more of said ducts of this manifold can have curved segments or sections, as shown on <FIG>, thus avoiding sharp angles and the above-mentioned problems. Such curved segments or sections have a non-zero (and finite) radius of curvature, for example at least <NUM>, in the plane of the network which allows a flow of liquid without pressure loss due to sharp angles. Preferably none of said ducts has sharp angles. Curved segments or sections contribute to a compact device, with less pressure losses and no possibility for ink or ink pigments to form residual solid growth on the ink flow.

Another example of a fluid component according to the invention is a damper <NUM> and various embodiments thereof are illustrated on <FIG>.

<FIG> are sections of a first embodiment of a damper <NUM> according to the invention.

It comprises a chamber <NUM>, delimited by a <NUM>st lateral wall <NUM> and an upper wall <NUM>, and further comprising a fluid inlet <NUM> and a fluid outlet <NUM> in a surface <NUM> forming a fluid connection area. Fluid connectors 511c and 513c are positioned against said fluid connection area <NUM> and in corresponding ducts. At least part of said fluid connection area and/or of one or both duct(s) can have the roughness of a component according to the invention (this applies as well to the other embodiments of a damper described below):.

It can further comprise a second chamber <NUM>, delimited by a <NUM>nd lateral wall <NUM> and a bottom wall <NUM>; said second chamber <NUM> can be filled with air (or any other gas) or communicates with the atmosphere outside the damper, for example through one or more holes <NUM> in a second or lower portion forming a cap or cover <NUM>; in the rest of this description, this part of the device can also be designated as the "second portion <NUM>".

A damping element comprises a flexible membrane <NUM>; its dimensions, in particular the surface of the membrane in contact with the fluid in chamber <NUM>, are calculated according to the pressures variations which must be damped in a CIJ printer. The membrane can have variable different aspects and/or thicknesses. Its thickness is for example between <NUM>,<NUM> and <NUM> or <NUM>. According to one example, the membrane is flat.

The membrane is formed by additive printing with the rest of the damper; it separates both chambers <NUM>, <NUM>.

A damper according to the invention is preferably rotational symmetrical, around an axis XX' which is substantially perpendicular to the membrane when it is at rest. In particular, said fluid receiving chamber and/or its upper portion <NUM>, and/or the membrane and/or said second chamber and/or its lower portion <NUM>, is/are preferably rotational symmetrical around said axis XX'.

Since the damper is manufactured by additive printing, there is no seal member inside the damper to ensure sealing between the different portions and between the fluid receiving portion <NUM> and the outside of the damper.

<FIG> shows that, under the influence of a pressure variation, for example of several bars, in the first fluid receiving portion <NUM>, the membrane <NUM> of the device presented on <FIG> is deformed in the second chamber <NUM>, where it does not come into contact with the bottom wall <NUM>. The deformation of the membrane <NUM> is preferably linear and elastic, based on a bending moment, the restoring force being given by the bending moment (to the difference with respect to <CIT>, where the restoring force results from the tensile force).

A variant of the structure of <FIG>, illustrated on <FIG>, is similar to <FIG> but does not comprise the second portion <NUM>. The membrane <NUM> and the first portion <NUM> form the chamber <NUM>. The advantage of the second chamber <NUM> of <FIG> is that it protects the membrane and also the outside atmosphere, should the membrane explode or be torn.

<FIG> is a section of a second embodiment of a damper <NUM> according to the invention, <FIG> showing a damping element of this second embodiment.

The damper <NUM> has the same general structure as the first embodiment.

It comprises a damping element <NUM>, which comprises a flat portion or membrane <NUM>; its thickness is for example between <NUM> and <NUM> or <NUM>. Thicknesses lower than <NUM> to shape the back surface are usually not compatible with pressures of up to <NUM> or <NUM> bars, which are usual in the field of continuous ink jet printers.

The damping element <NUM> further comprises damping rings or damping studs <NUM>, <NUM>, <NUM> which protrude from said flat portion or membrane <NUM> and which can bear on the lower surface <NUM> thereby damping the pressure variations without impairing the flexibility of the membrane. They are disposed along circles centered on the center of the membrane <NUM>. On <FIG>, <NUM> rings and a central stud are represented, but other embodiments may comprise only <NUM> rings <NUM>, <NUM> or <NUM> ring (for example ring <NUM>) and one central stud <NUM>; alternatively, one or more ring(s) can be replaced by a series of studs aligned according to a circle; this variant is shown on <FIG> which is a view from above the surface of the damper comprising the damping studs: it comprises <NUM> series <NUM>, <NUM> of studs, each series being disposed along a circle centered on the center of the membrane <NUM>.

The damping member(s) <NUM> forms a sealed separation being the fluid receiving portion <NUM> and the second chamber <NUM>.

Like in the previous embodiment, there is no need for any seal between fluid receiving portion <NUM> and the second chamber <NUM> and between fluid receiving portion <NUM> and the outside of the damper. The seal is formed by the membrane itself.

<FIG> shows that a pressure variation, for example of several bars, in the first fluid receiving chamber <NUM>, deforms the damping membrane <NUM> of the device presented on <FIG>, as well as the damping rings or damping studs <NUM>, <NUM>, <NUM> which bear on the lower surface <NUM>, thus ensuring a damping effect of the pressure variation. A same or similar effect is obtained for a damping member <NUM> according to <FIG>.

A damper according to the invention does not need any clamping or fastening means.

In another embodiment, illustrated on <FIG>, one the two parts <NUM>, <NUM> is larger than the other one, both parts being manufactured in a same 3D printing process.

On <FIG>, the second portion <NUM> has a lateral wall <NUM> which extends outside the first portion <NUM>. The second portion can further comprise a circular crown <NUM>, which delimits chamber <NUM> and which supports the lateral side of the membrane <NUM>. This embodiment can also be implemented with a damping element as disclosed in connection with <FIG> (the second portion not comprising an internal circular crown <NUM>).

Alternatively, as illustrated on <FIG>, the first portion <NUM> has a lateral wall <NUM> which extends outside the second portion <NUM>. This embodiment can also be implemented with a damping element as disclosed in connection with <FIG>.

A damper according to the invention has a damping factor of up to <NUM> % or even <NUM>%: for example, a pressure variation of <NUM> bars can be damped down to <NUM> bar or even <NUM> bar. The fluid receiving chamber of a damper according to the invention can have a small height (distance between the upper surface of the membrane <NUM> and the upper wall <NUM>), for example between <NUM> and <NUM>, resulting in a fluid receiving portion <NUM> having a low volume, for example between <NUM><NUM> and <NUM><NUM> mm<NUM>. The efficiency of the damper is not affected by such a small volume, the damping efficiency resulting from the surface of the membrane in contact with the fluid receiving portion, not from the volume of the fluid receiving portion. But the fluid receiving portion can be optimized to minimize the fluid pressure drop (the so-called hydraulic resistance). A volume of, for example, between <NUM><NUM> and <NUM><NUM> mm<NUM> allows this optimization because the flow cross-section between inlet <NUM> and outlet <NUM> is still important and therefore the flow of the fluid, and the hydraulic resistance can be small enough.

Alternatively, a further variant of a damper according to the invention is illustrated on <FIG> and comprises two circular flat membranes <NUM><NUM>, <NUM><NUM> (or flexible plates) parallel to each other, thus delimiting a fluid receiving portion or chamber <NUM>. The damper is provided with a fluid inlet <NUM> and a fluid outlet <NUM>. Each membrane <NUM><NUM>, <NUM><NUM>:.

Each membrane <NUM><NUM>, <NUM><NUM> separates the receiving portion <NUM> from a second chamber <NUM>, <NUM>', delimited by a cover portion <NUM>, <NUM>' similar or identical to cover portion <NUM> already described above in connection with <FIG>.

A variant of the structure of <FIG> does not comprise the cover portions <NUM>, <NUM>'. The fluid receiving chamber is closed by the membranes <NUM><NUM>, <NUM><NUM> and the device can work without second chambers <NUM>, <NUM>'. The advantage of each second chamber <NUM>, <NUM>' of <FIG> is that it protects the membranes and also the outside atmosphere, should one of the membranes explode or be torn.

Due to the 3D manufacturing process, the different parts of the device do not need to be assembled and clamped or fastened together with any.

<FIG> shows that each damping membrane <NUM><NUM>, <NUM><NUM> of the device presented on <FIG> is deformed under a pressure variation, for example of several bars, in the fluid receiving chamber <NUM>; this deformation ensures a damping effect of the pressure variation.

Alternatively, this embodiment can be implemented with damping elements as disclosed in connection with <FIG>, each comprising damping rings or damping studs <NUM>, <NUM>, <NUM> which can bear on the surfaces <NUM>, <NUM>' and are for damping the pressure variations. It forms a separation being the fluid receiving portion <NUM> and one of the second chambers <NUM>, <NUM>'. The diameter and/or thickness of each membrane can be those already mentioned above in connection with <FIG>.

The damping effect can be reinforced by implementing two dampers <NUM><NUM>, <NUM><NUM> in series, each according to the invention, as illustrated on <FIG>, the fluid circulating through the first damper <NUM><NUM> and then through the second damper <NUM><NUM> (both dampers being connected through a duct <NUM>) before flowing to the print head. Each damper <NUM><NUM>, <NUM><NUM> can be a damper according to any embodiment of the invention. References <NUM> and <NUM> designate the inlet ducts into the first damper and the second damper and reference <NUM> is the outlet duct out of said second damper.

Any embodiment of a damper according to the invention can be implemented in an ink circuit of a CIJ printer comprising a gear pump to pump the ink; this kind of pump has pressure variations in a range of <NUM> to <NUM> bars or <NUM> to <NUM> bars; alternatively a diaphragm pump can be implemented, having pressure variations in a range of <NUM> mbars to <NUM> mbars. Both pressure variations can be efficiently dampened by a damper according to the invention, the pressure variations being damped down to a factor comprised between <NUM>% and <NUM>% of the above-mentioned ranges.

A damper according to the invention and as described above, for a continuous ink jet printer, comprises a fluid receiving chamber <NUM>, which comprises at least a lateral wall <NUM>, a fluid inlet 511c and a fluid outlet 512c, and at least one membrane <NUM>, <NUM><NUM>, <NUM><NUM>, <NUM>, <NUM> said membrane being deformed under the influence of a pressure variation.

In a particular embodiment, it can comprise a second chamber <NUM>, <NUM>', <NUM> said membrane being comprised between said fluid receiving chamber and said second chamber.

As explained above, both sides of the membrane can be flat or can have a complex shape with a variable thickness. Alternatively, if the damper comprises a second chamber, the side of said membrane turned towards said second chamber can further comprise damping means <NUM>, <NUM>, <NUM>, <NUM> protruding from said membrane.

A damper according the invention can be cylindrical, extending along an axis XX'.

In particular embodiments, a damper according the invention can comprise:.

A fluid circuit of a continuous ink jet printer can comprise a first conduit, <NUM> a second conduit <NUM> and at least one damper according to the invention, said first conduit being connected to said fluid inlet and said second conduit being connected to said fluid outlet of said at least one damper. Said fluid circuit can comprise a second damper <NUM><NUM>, for example also according to the invention, said second conduit being connected to a fluid inlet of said second damper, a third conduit <NUM> being connected to a fluid outlet of said second damper.

A fluid circuit of a continuous ink jet printer can further comprise a reservoir and a pump, for example a gear pump or a diaphragm pump, connected to an inlet of said first conduit, said second conduit being connected to a printing head.

A method for damping pressure variations, for example of between <NUM> bar and <NUM> bar in a fluid circuit of a continuous ink single jet printer, can comprise circulating said fluid in at least one damper according to the invention, said pressure variations deforming said at least one membrane which thus damps said pressure variations.

A damper according to the invention is adapted to a continuous inkjet (CIJ) printer comprising a single-nozzle or a multi-nozzle ink jet print head, as represented on <FIG> and <FIG> of <CIT>.

A damper according to the invention is connected between an inlet conduit and an outlet conduit of a fluid circuit of a CIJ printer, for example of a circuit connecting a reservoir and the printing head. Said circuit further comprises a pump for pumping fluid from the reservoir. Pressure variations of this fluid are damped by the damper according to the invention.

The damper according to one of the above embodiments can be implemented in a continuous ink jet printer as illustrated on <FIG>, for example at the outlet of pump <NUM> for pumping solvent.

It can for example be connected to chamber <NUM> of the device illustrated on <FIG>. It can be manufactured together with said device during a same 3D printing process.

The fluid connection area(s) of any component or device or part according to the invention, which area(s) is/are for receiving a fluidic device or component, for example a valve, can have either counterbores, in which sealing means, for example one or more gasket(s), can be positioned. This area preferably has a roughness Ra which is preferably less than <NUM> or less than <NUM> or <NUM>, more preferably less than <NUM>, for example <NUM>,<NUM>, so that sealing means can be pressed against said surface and efficiently seal an assembly of a device according to the invention and another fluidic device or component.

As already explained above, the inner or inside surface of one or more duct(s) of any component or device or part according to the invention can also have a desired roughness, for example less than <NUM> or less than <NUM> or <NUM>, more preferably less than <NUM>, for example <NUM>,<NUM>.

As explained below, the roughness of any fluid connection area(s) and/or of any inside surface of the ducts of any component or device according to the invention can be obtained by selecting and preparing an appropriate material and a manufacturing process of the component or the device.

Any component or device or part according to the invention is preferably made by a 3D printing technology, for example one of the following technologies: extrusion, Material Jetting, Photo-polymerization and Powder bed fusion. These technologies are for example described in the article by <NPL>.

Powder bed fusion is currently the preferred solution because it is adapted to industrial needs.

Several other technologies can also be implemented in the frame of the present invention: SLS (Selective Laser Sintering), SHS (Selective Heat Sintering) and EBM (Electron Beam Melting) as described in the above cited publication or other technologies such as DMLS (Direct Metal Laser Sintering), which is similar to SLM (Selective Laser Melting). Hybrid technologies are also available; they combine powder bed fusion and binder jetting such as powder bed selective heat absorbing assisted by 2D printing technology.

3D printing technology makes use of data of a Computer Aided Design model of the component to be manufactured, which generates a file <NUM> (<FIG>) of a 3D model of the component, or an already existing data file <NUM> of a 3D model of said component is already available. Said data of said file <NUM> are read by a computer <NUM> which is adapted to control a 3D printer <NUM> accordingly.

Under control of computer <NUM>, the selected material is deposited layer by layer <NUM><NUM> - <NUM>n (<FIG>, n being any integer number), by said 3D printer <NUM> on a support <NUM> through one or more nozzles <NUM> of the 3D printer. Each layer <NUM><NUM>, <NUM><NUM>,. ;<NUM>n has for example a thickness of between <NUM> or <NUM> and <NUM> or <NUM>, compatible to achieve the required roughness; alternatively, said 3D printing process can be supplemented with an additional step of smoothing at least one fluid connection area and/or at least part of the inner surfaces of one or more duct(s). The 3D printing process of <FIG> is performed on a substrate <NUM> which can be more or less inclined with respect to the flow <NUM> of material: on <FIG>, the substrate <NUM> is horizontal but it can be inclined to another position <NUM>' which makes an angle α (for example: <NUM>°< α <<NUM>°) with respect to the horizontal position, although printing is still performed "horizontally", as can be understood from <FIG>, on which the deposited layers rest on a support <NUM>.

In both cases one of the surfaces, for example the top surface <NUM> (in, particular with the extrusion process) or the bottom surface <NUM>' of a succession of layers <NUM><NUM> - <NUM>n or <NUM>'<NUM> - <NUM>'n deposited by 3D printing has a much better (smaller) roughness than the other surfaces of sides, for example a better roughness than the lateral sides <NUM><NUM>, <NUM><NUM>, <NUM>'<NUM>of the stack of layers. Depending on the quality (and in particular of the roughness Ra) of the upper surface of substrate <NUM>, the best roughness Ra can be obtained at bottom surface <NUM>' which is directly in contact with said upper surface.

Therefore, printing is performed taking into account the area or surface of the component which must have a better roughness than the other parts. This can be for example area <NUM> of component <NUM> (<FIG>) or area <NUM> of component <NUM> (<FIG>) or area <NUM> or <NUM> of the component of <FIG> or the area <NUM> of component <NUM> of <FIG>, each of these areas or surfaces forming a fluid connection area of a device according to the invention; such area is preferably smooth enough so that sealing means, for example a gasket, can be applied against it and efficiently seal the area where it is located. Said area preferably has a roughness less than <NUM> or less than <NUM> or less than <NUM>, for example <NUM>,<NUM>.

Another example of 3D printing process is illustrated on <FIG>: it implements a build tank <NUM> is which the material <NUM>, for example powder, from which the component must be manufactured is collected, layer by layer. A laser beam <NUM> is directed to the surface <NUM> of the bed <NUM> to generate fusion of the material on said surface and in the deposited layer immediately under said surface: this technique can in particular be implemented if the material is a metal. Alternatively, a binder is projected onto said surface to assemble the particles: this technique can in particular be implemented for a plastic material.

When the material of the surface <NUM> and in its directly underlying layer is transformed, either by the laser or by the binder, another layer of material is added onto the bed <NUM>, the material of said other layer being also processed. The component is manufactured in an order which depends on the ability of the selected printing technique to generate a desired roughness on a specific surface or area. For example, the process illustrated on <FIG> may be able to generate a surface of said component having a specific orientation, for example surface <NUM>', which has a required roughness: in this case, the component is manufactured so that surface <NUM>' has the orientation shown on <FIG>. Depending on the printing conditions, the surface <NUM>' can have a better roughness when the final component is oriented as illustrated on <FIG>. As illustrated on these <FIG>, any of these orientations may not be horizontal. Which orientation should be selected for a specific area in order for it to have the required roughness Ra can be tested by trial and error.

If the roughness of an area of a component obtained by 3D printing is too high, it can be further processed after 3D printing; for example, it can be machined or smoothed or grinded, or polished; alternatively, or in addition, it can also be chemically processed (in particular for plastic materials), for example in a bath of abrasive or corrosive fluid, for example a liquid comprising corundum or diamond particles or an acid (HCl).

In some cases, after the 3D printing process, one area, for example the top surface <NUM> or the bottom surface <NUM>' has the desired roughness but the roughness of another area remains too high; in that case, one or more other area(s) than area <NUM>, <NUM>' can be further processed, they are for example machined or smoothed or grinded, or polished. This can be the case for a component like the one illustrated on <FIG>: this component can be 3D printed so that a major fluid connection area <NUM> - against which several solenoid valves can be connected - is the surface of the stack of layers which has the best roughness, for example the bottom of layer <NUM>' of <FIG>; if surface <NUM> of the component must also have a desired roughness but the conditions are not as favourable for this surface as for surface <NUM>, its roughness just after 3D printing may be too high: in this case, surface <NUM> can be further processed according to one of the above methods.

As explained below, a manifold according to the invention is preferably made of metal, for example stainless steel or ceramic or plastic. Depending on the material, an adapted 3D printing method can be selected, for example from the above list of methods. For powder bed 3D printing, the material is a powder which is deposited and/or heated during the 3D printing process.

The design of the component is also taken into account, in order to take advantages of the abilities offered by the selected 3D printing technique. In particular, fluid connections should be optimized in order to ease the obtaining of the appropriate roughness, through the number of connections in a fluid connection areas and its position. This way, appropriate roughness should be obtained directly during additive manufacturing; or the component should be placed or have an orientation such that it can be smoothed during post-processing.

The duct(s) and the fluid connection area(s) of a component or part according to the invention, or of a component or part of a CIJ printer according to the invention, are preferably made by the same 3D printing or additive manufacturing process. But said whole component or part, for example any mechanical link between two ducts, is also made by said process.

Roughness can be measured by a roughness measuring system or roughness meter (implementing for example a mechanical stylus or an optical type method). Roughness can be defined by Ra, the arithmetic average of the surface profile z(x), along a straight line of length Lr : <MAT>.

More information about the definition of the roughness Ra and about possible measuring techniques can be found in chapter <NUM> ("<NPL>) of the <NPL>.

The roughness obtained by any 3D printing process is between <NUM>/<NUM> and ½ of the average diameter of the grain of the powder used for 3D printing.

Using metal powder which grains had different diameters, the inventors have obtained the following results with a powder bed fusion process and layers having a thickness between <NUM> and <NUM>:.

It is clear that a stricter selection of the average grain diameter, or selection of appropriate surface, for example lower layer in contact on a glass substrate, would give better results and a roughness meeting the requirements of the present invention.

The same holds for other materials than metal. For example, using a plastic powder having an average grain diameter of <NUM>, a layer of <NUM> thickness was deposited by 3D printing; the roughness Ra of the all surfaces was <NUM> <Ra<<NUM>, before any further polishing step.

It is therefore possible to adapt the selected powder, and in particular the size of the grains, according to the desired roughness, in particular in order to obtain the roughness of a fluid connection area and/or of the inner surface of a duct according to the invention.

The density of the powder may also play a role: a dense powder being more favourable to obtain a smaller roughness, in particular in the case of metal powder for example with powder bed fusion metal technique; it is therefore recommended to densify the powder before 3D printing.

One or more duct(s) <NUM> (<FIG>) can also be made during 3D printing: indeed, as can be understood from the above description, a component according to the invention can have one or more ducts in which one or more fluid, for example ink and/or a solvent adapted for a CIJ printer can circulate.

One or more duct(s) of a component according to the invention can be for circulating ink, which comprises solvent but also pigments and binders. The inside walls, along which the fluid circulates and which are in contact with ink and/or solvent, are preferably as smooth as possible, their roughness being preferably less than <NUM>, or less than <NUM>, more preferably between <NUM> and <NUM>,<NUM>. Thus, pigments of ink cannot remain attached to the inner surface of the conduct, where they could form residual solid growth on the ink flow.

The desired or required roughness can be achieved by 3D printing. A further step can be performed after 3D printing if the roughness obtained by 3D printing is too large; for example, smoothing of the ducts can be achieved by circulating an abrasive or corrosive fluid in the device after 3D printing, for example a liquid comprising corundum or diamond particles or an acid (HCl).

Alternatively, if both a fluid connection area and the inside of a duct of a same component must be further processed, the component can be dipped into a bath of an abrasive or corrosive fluid in the device after 3D printing.

The material to manufacture any device or component according to the invention offers chemical resistance to ink/solvent, defined as the stability of the device after at least <NUM>, <NUM> or <NUM> weeks soaking (or immersion) in at least one organic solvent, for example at least one solvent suitable for CIJ printing (for example at least MEK, and/or C5 ketone - pentanone -, such as MIPK -Methyl Isopropyl Ketone- and/or MPK -Methyl Propyl Ketone-, and/or Ethanol), or in an ink based on any of said solvents, at a temperature of at least <NUM> or <NUM>, this stability determined by a variation of weight and/or of at least one dimension of less than <NUM>%, preferably less than <NUM>%, more preferably less than <NUM>%.

Examples of material offering such resistance are plastic materials, like "Nylon" (PA11, or PA12), polyamides, PEEK, PPS (polyphenylene sulphide), stainless steel. But other materials, for example metals, can be implemented; or ceramics In addition to having chemical resistance, the selected material preferably offers mechanical robustness, and is preferably fire-retardant.

Several components can be formed with a minimum amount of material, as for example illustrated in connection with <FIG>.

Such a component - also called topologically optimized component - has a very light weight, a low cost and can fulfill the same functions as the original component while minimizing material consumption. It can include one or more mechanical reinforcing element(s) for example at least one wall <NUM> (<FIG>, <FIG>) or at least one beam so that the component remains robust and mechanically strong. End parts, comprising the fluid connection surface(s), also contribute to the strength of the component.

In such a topologically optimized component, the walls of the ducts have for example a thickness of between <NUM> and <NUM>, or between <NUM> and <NUM>, which saves all the material which is normally between the ducts. The thickness of the wall of the ducts is preferably selected based on the material and the required rigidity of the component, in particular with respect to the fluid pressure (for example up to <NUM> bars).

One or more fluid component(s) according to the invention is adapted to a continuous inkjet (CIJ) printer comprising a single-nozzle or a multi-nozzle ink jet print head, as represented for example on <FIG> and <FIG> of <CIT> and described in this same document.

Alternatively, one or more fluid component(s) according to the invention can be incorporated in a CIJ inkjet as illustrated on <FIG>.

As illustrated on this figure, this printer comprises an ink cartridge receiving portion 682a to receive an ink cartridge <NUM> and a solvent cartridge receiving portion 684a to receive a solvent (or organic solvent) cartridge <NUM> (both cartridges can be removed from the circuit) and an ink supply system comprising an ink circuit, which can include a main reservoir <NUM>. The receiving portions allow a circulation or a flow of fluid (ink and/or solvent) from each cartridge(s) to said ink circuit, comprising fluid conduits or ducts. Thus, ink can be supplied to a print head <NUM>.

In the example illustrated on <FIG>, said ink circuit can comprise a module <NUM> (or manifold) and several ducts to connect the receiving portions 682a and 684a to the circuit, comprising the main reservoir <NUM> and different modules <NUM>, <NUM>, <NUM>.

An example of module <NUM> was already described above (see <FIG>): it can comprise an ink portion, comprising said ink cartridge receiving portion, and a solvent portion comprising said solvent cartridge receiving portion, the ink portion being for a connection to an ink pump <NUM> for pumping the ink from an ink cartridge <NUM> and the solvent portion being for a connection to a pump <NUM> for pumping the solvent from a solvent cartridge <NUM>. The outlet of the solvent pump <NUM> (on line <NUM>) can be provided with a damper <NUM>, to damp the oscillations of the solvent resulting from the pump <NUM>; said damper is for example as described above in connection with <FIG>.

Module <NUM> can also comprise a number of <NUM>-way valves <NUM><NUM>, <NUM><NUM>, <NUM><NUM>, <NUM> to send the appropriate fluid to the ink circuit, for example to the appropriate module <NUM>, <NUM>, <NUM> and/or to the reservoir <NUM>.

Examples of modules <NUM>, <NUM> are described below, an example of module <NUM> was already described above (see <FIG>).

Ducts <NUM>-<NUM> can connect the ink portion and the solvent portion of the hydraulic module <NUM> with main reservoir <NUM>; ducts <NUM>-<NUM> can connect the ink portion and the solvent portion of the hydraulic module <NUM> with the different modules <NUM>-<NUM> as shown on <FIG>.

Each of the modules <NUM>, <NUM>, <NUM> can be maintained in the circuit by appropriate fastening or securing means, for example one or more screw(s), or nut(s), or bolt(s), or clip(s), or clamp(s) or hook(s) or any other securing or fastening means so that each module can be mounted on the circuit and dismounted or removed from said circuit.

The main reservoir <NUM> can be for example of the type comprising two compartments as disclosed in <CIT>, the upper compartment <NUM><NUM> for storing ink and the lower compartment <NUM><NUM> for storing solvent:.

In an example, filter module <NUM> comprises a housing <NUM>, possibly including a cover <NUM>; said module comprises one or more fluid inlet(s) <NUM>, <NUM>, and one or more fluid outlet(s) <NUM>, <NUM>; inside the module or its housing, one or two filter(s) <NUM> (a so-called "grid filter"), resp. <NUM> (a so-called "main ink filter") is/are connected to a corresponding set of fluid inlet <NUM> and fluid outlet <NUM>.

Another filter <NUM> (in this example: a filtering grid) can be connected between main filter outlet <NUM> and the fluid outlet <NUM>.

The ink circuit can have a receiving portion or zone or interface to receive the filter module and connect it to the hydraulic circuit of the printer. Said receiving portion or zone or interface has at least two fluid inlets which correspond to the fluid outlets <NUM> and <NUM> and at least two fluid outlets which correspond to the fluid inlets <NUM> and <NUM> of said filter module, so that fluid can flow from said interface outlet(s) into said filter module and then out of said filter module to said interface inlet(s). The filter module can be mounted in or on the ink circuit or on said receiving portion or zone or interface; it can be demounted from said circuit or from said receiving portion or zone or interface of the ink circuit. For example, one or more screw(s), or nut(s), or bolt(s), or clip(s), or clamp(s) or hook(s) or any other securing or fastening means can be used to mount and remove said filter module.

Recovery module <NUM> can comprise a housing <NUM>, possibly including a cover <NUM>; said module comprises one or more fluid inlet(s) <NUM>, <NUM>, <NUM>, and one or more fluid outlet(s) <NUM>, <NUM>; inside the housing, a recovery device, for example a venturi or a diaphragm pump <NUM>, is for recovering from the printing head ink not used for printing, the recovery device outlet being connected to one of the fluid outlets <NUM>, <NUM>; a filter <NUM> can be connected between the fluid inlet <NUM> and the recovery device in order to filter said ink recovered from the printing head; at least one <NUM>-way valve <NUM> can also be connected between the filter <NUM> and the pump <NUM> in order to select a fluid from inlet <NUM> (usually ink returning from the print head) or inlet <NUM> (usually solvent or air).

The ink circuit can have a receiving portion or zone or interface <NUM> to receive the recovery module and connect it to the hydraulic circuit of the printer. The recovery module can be mounted in or on the ink circuit or on said receiving portion or zone or interface; it can be demounted from said circuit or from said receiving portion or zone or interface of the ink circuit. For example, one or more screw(s), or nut(s), or bolt(s), or clip(s), or clamp(s) or hook(s) or any other securing means can be used to mount and remove said module.

Said receiving portion or zone or interface has at least two fluid outlets which correspond to the fluid inlets <NUM>, <NUM>, <NUM> and at least two fluid inlets which correspond to the fluid outlet <NUM>, <NUM>, so that fluid can flow from said interface outlets into said module <NUM> and then out of said module <NUM> to said interface inlets.

As can be seen on <FIG>, a damper <NUM> can be connected on the fluid path to the inlet <NUM> of the filter module <NUM> (between fluid outlet <NUM> of module <NUM> and fluid inlet <NUM> of module <NUM>), in order to damp the pressures variations or oscillations of the ink before sending it to the print head, such pressures variations or oscillations being generated by the pump and degrading the print quality. The fluid then flows through filter <NUM> and is then sent to the print head through part of the fluid circuit (for example through a fluid manifold as illustrated on <FIG> by arrows <NUM> and <NUM>), and in particular through the filter <NUM>.

A <NUM>-way valve <NUM> can be connected to the outlet <NUM> of the filter module <NUM>. Depending on the operation stage of the printer, the fluid flowing out of the filter module <NUM> can be sent, through the valve <NUM>, either to the print head <NUM> (possibly through an additional filter <NUM>) or to the main reservoir of the circuit (through the recovery module <NUM>). A sensor <NUM> can be implemented to measure the pressure and/or the temperature of the fluid flowing out of the filter module <NUM>. The combination of valve <NUM> and sensor <NUM> is represented in connection to module <NUM>, an embodiment of which being illustrated on <FIG> and 2E.

A <NUM>-way valve <NUM> can be connected to the inlet <NUM> of the pump module <NUM>. Depending on the operation stage of the printer, the fluid flowing into the pump module <NUM> can be from the reservoir <NUM> or from the printer manifold. The valve <NUM> (described above in connection with any of <FIG>) is represented in a body or manifold <NUM>, an embodiment of which being illustrated on <FIG>.

Damper <NUM> is represented in a module <NUM> which can also be made by additive printing according to the invention, the damper being positioned against the fluid connection area of this module after 3D printing.

Each of the modules <NUM>, <NUM>, <NUM> can also be made by additive printing according to the invention:.

A CIJ printer, for example the one illustrated on <FIG>, is used in combination with a print head <NUM>, which can be according to one of the embodiments of <FIG>.

Claim 1:
A fluid component (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) for a continuous inkjet printer, comprising:
at least two ducts (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), each duct having an inner surface and each duct extending between a first end and a second end, the at least two ducts being configured for circulation of a fluid comprising an organic solvent,
at least one fluid inlet and at least one fluid outlet, and
at least one fluid connection area (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprising at least one of said at least one fluid inlet and at least one fluid outlet,
characterised in that said fluid component being a one-piece fluid component made of a material chemically resistant to the organic solvent, and in that at least part of said fluid connection area has a roughness (Ra) of less than <NUM> and at least part of the inner surface of at least one duct has a roughness (Ra) of less than <NUM>.