Fluid ejection cartridge and method for manufacturing a sintered metal cartridge

Abstract

The present invention provides a fluid ejection cartridge and a method for manufacturing a sintered metal cartridge, having a single-piece integrally formed body made of sintered metal, the body having an upper portion, a lower portion, side walls, and a bottom having nozzles, the body constituting a reservoir. In various embodiments, the body comprises at least one of the following: copper, copper alloy, ferrous steel, carbon steel, iron-copper steel, copper-infiltrated steel, copper steel, iron-nickel steel, nickel steel, low alloy steel, hardened steel, diffusion alloy steel, 300 series stainless steel, 400 series stainless steel, and soft magnetic alloy. Some embodiments include a lid of sintered metal disposed over and sealed to the upper portion of the body. Some embodiments include a chip in fluid flow communication with the reservoir. Some embodiments include a filter disposed in the reservoir at the lower portion of the body. Some embodiments include a volume of ejectable fluid disposed within the reservoir.

Description

Technical Field

[0001] This disclosure relates to the field of ink cartridge systems for fluid ejection. More particularly, this disclosure relates to an ink cartridge system for fluid ejection having a molded sintered metal ink cartridge body. Background Art

[0002] Fluid ejection ink cartridges are used to eject or dispense fluids in a variety of different applications such as conventional inkjet printing. Most of the inks used in these printing systems are water-based and are printed on paper or some other common substrate. Ink cartridges for such applications can be formed from a variety of inexpensive materials such as plastics, which are relatively easy to use and sufficient for such low-demand applications.

[0003] However, in environments with higher or more regulated requirements than standard consumer printing operations, there are many ejection applications that use solvents other than water to dispense materials other than standard ink pigments. For example, some applications require the dispensing of non-aqueous solvent-based materials, and some applications regulate the types of equipment that can be used, such as food service or drug delivery applications.

[0004] Unfortunately, the plastics used in conventional inkjet printing ink cartridges may not be chemically resistant to the non-aqueous solvents required in some of these applications, or may not be cleanable enough to meet the regulatory standards of such applications.

[0005] Accordingly, what is needed is a fluid ejection ink cartridge and a method of manufacturing the same that tend to at least partially reduce problems such as those presented above. Summary of the Invention

[0006] A fluid ejection ink cartridge meets the above and other needs, the fluid ejection ink cartridge having a single-piece integrally formed body made of sintered metal, the body having an upper portion, a lower portion, side walls, and a bottom having nozzles, the body constituting a reservoir.

[0007] In various embodiments of this aspect of the invention, the body comprises at least one of: copper, copper alloy, ferritic steel, carbon steel, iron-copper steel, copper-infiltrated steel, copper steel, iron-nickel steel, nickel steel, low alloy steel, hardened steel, diffusion alloy steel, 300 series stainless steel, 400 series stainless steel, and soft magnetic alloy. Some embodiments include a lid of sintered metal disposed over and sealed to the upper portion of the body. Some embodiments include a chip in fluid flow communication with the reservoir. Some embodiments include a filter disposed in the reservoir at the lower portion of the body. Some embodiments include a volume of ejectable fluid disposed within the reservoir.

[0008] In some embodiments, the ejectable fluid comprises at least one organic solvent selected from the group consisting of alcohols, acetate esters, ketones, hydrocarbon solvents, halogenated solvents, and lactones, and is not an aqueous solvent. In some embodiments, the ejectable fluid comprises at least one organic solvent selected from the group consisting of methanol, ethanol, isopropyl alcohol, butanol, 1-methoxy-2-propanol, 2-butoxyethanol, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, benzene, toluene, xylene, hexane, petroleum, chloroform, diiodomethane, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, and γ-butyrolactone, and is not an aqueous solvent. In some embodiments, the ejectable fluid is a printing ink and further comprises a pigment or a dye.

[0009] According to another aspect of the present invention, a method for manufacturing a sintered metal cartridge is described by forming a precursor material of a metal and a binder into a shape of a cartridge having side walls and a bottom having a nozzle, and heating the precursor material to transform the precursor material into a sintered metal part.

[0010] Various embodiments according to this aspect of the present invention include an initial heating step to remove the binder from the metal in the precursor material. Some embodiments include a final heating step to cause the metal to flow into the sintered metal part. Some embodiments include post-treating the sintered metal part by at least one of cleaning, passivating, polishing, deburring, marking, and engraving. Some embodiments include placing a filter into the sintered metal cartridge. Some embodiments include inserting a fluid absorbent block into the sintered metal cartridge. Some embodiments include attaching a flexible circuit and a chip to the sintered metal cartridge. Some embodiments include filling the sintered metal cartridge with an ejectable fluid. Some embodiments include attaching a lid to the sintered metal cartridge. Some embodiments include attaching a lid to the sintered metal cartridge, wherein the lid is formed of sintered metal. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] When considered in conjunction with the drawings which are not to scale so as to show details more clearly, additional advantages of the present invention are apparent from the detailed description, wherein like reference numerals indicate like elements throughout the several views, and wherein:

[0012] Figure 1 is a fluid ejection cartridge according to an embodiment of the present invention.

[0013] Figure 2 is a flow chart of a method for forming a fluid ejection cartridge according to an embodiment of the present invention.

[0014] REFERENCE NUMERAL DESCRIPTION

[0015] 10: Cartridge;

[0016] 12: Body;

[0017] 14: Upper part;

[0018] 16: Lower part;

[0019] 18: Side wall;

[0020] 20: Cavity;

[0021] 22: Fluid reservoir;

[0022] 24: Lid;

[0023] 26: Bottom;

[0024] 28: Nozzle;

[0025] 30: Fluid ejection chip;

[0026] 32: Absorbent block;

[0027] 34: Fluid filter element;

[0028] 36: Flexible interconnect circuit;

[0029] 200: Flowchart

[0030] 202, 204, 206, 208, 210, 212, 214, 216, 218, 220: Boxes. Detailed Description

[0031] The present disclosure describes a fluid ejection cartridge suitable for use with a fluid mixture having an organic solvent base relative to an aqueous solvent base. As described in more detail below, the described cartridge can also be used in food service or drug delivery applications. Also described is a method for manufacturing the cartridge.

[0032] Reference is now made to Figure 1 , depicting a cartridge 10 according to an embodiment of the present invention, the cartridge 10 having a body 12 with an upper part 14, a lower part 16, a side wall 18, and a bottom 26 disposed below and integrally formed with the lower part 16 of the cartridge body 12. A hollow cavity 20 is created within the body 12 by the side wall 18 and the bottom 26, the cavity 20 constituting a reservoir 22. The cartridge 10 as depicted in this embodiment also includes a lid 24. The lid 24 is a separately formed piece that is disposed over and sealed to the upper part 14 of the body 12.

[0033] It should be noted that, according to an embodiment of the present disclosure, both the body 12 and the lid 24 are made of sintered metal materials. As used herein, sintered metal comprises a metal that is formed from a powdered metal precursor mixed with an organic binder material, pressed into a desired shape, and then heated to remove the binder material and fuse the metal into a solid, non-porous piece having the desired shape. Examples of such metals include copper and copper alloys, iron and carbon steels, iron-copper steels, copper-infiltrated steels, copper steels, iron-nickel and nickel steels, low alloy steels, hardened steels, diffusion alloy steels, 300 series stainless steels, 400 series stainless steels, and soft magnetic alloys.

[0034] As described above, the lid 24 is sealed to the upper portion 14 of the body 12. In various embodiments, the lid 24 can be sealed to the body 12 using an adhesive, sintered metal, press fitting, or welding.

[0035] The ink cartridge 10 further includes a nozzle 28, which is part of the bottom 26 and has a specific function to support at least one fluid ejection chip 30 that is in fluid flow communication with the fluid reservoir 22 via holes in the nozzle 28. The ejection chip 30 includes a plurality of nozzles for ejecting fluid from the reservoir 22. In certain embodiments, the ink cartridge 10 further includes an absorbent block 32 disposed within the fluid reservoir 22 and a fluid filter element 34 disposed between the fluid reservoir 22 and the fluid ejection chip 30.

[0036] In addition, many embodiments of the ink cartridge 10 include a flexible interconnect circuit 36 attached to the sidewall 18 and electrically connected to the fluid ejection chip 30 for providing electronic control of the ejection chip 30.

[0037] By forming the body 12 of the ink cartridge 10 from sintered metal, the amount of flexure of the body 12 and the degree of thermal expansion and contraction of the body 12 tend to be reduced compared to what a typical plastic body 12 would experience under similar environmental conditions. This tends to reduce the stress applied to the fluid ejection chip 30, which tends to decrease the frequency of occurrence of chip 30 breakage and chip 30 separation from the body 12.

[0038] The ink cartridge 10 contains a volume of ejectable fluid disposed within a fluid reservoir 22 and, in some embodiments, a permeable absorbent block 32. In some embodiments, this ejectable fluid is an aqueous mixture. In other embodiments, the ejectable fluid is a non-aqueous organic-based solvent. For example, the ejectable fluid is an organic solvent comprising at least one of the following: alcohols, acetates, ketones, oils, hydrocarbon solvents, halogenated solvents, and lactones. In some more specific embodiments, the ejectable fluid comprises at least one of the following: methanol, ethanol, isopropanol, butanol, 1-methoxy-2-propanol, 2-butoxyethanol, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, benzene, toluene, xylene, hexane, petroleum, chloroform, diiodomethane, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, and γ-butyrolactone.

[0039] In some embodiments, the fluid ejection ink cartridge 10 is used as an inkjet printing cartridge. In some embodiments, the ejectable fluid within the ink cartridge 10 is a suitable printing ink and comprises solid pigment particles dispersed within a solvent. In some embodiments, the ink cartridge 10 is used in the food preparation industry, for example, by ejecting food coloring or other edible materials onto the surface of foods such as cookies and cakes.

[0040] In other embodiments, the fluid ejection ink cartridge 10 is used for purposes other than printing. For example, the fluid ejection ink cartridge 10 of the present disclosure can be used for the controlled fluid release of perfumes or essential oils, for delivering drugs in fluid amounts, or for delivering fluids in an electronic atomization device.

[0041] In some embodiments, the fluid ejection ink cartridge 10 of the present disclosure is used for printing on non-porous substrates. For example, the ink cartridge 10 can be used in a drop-on-demand printing system to print desired markings on substrates such as plastics, metals, glass, and plastic-coated paper. In other embodiments, the ink cartridge 10 is used to print on more porous substrates such as uncoated paper.

[0042] In printing on non-porous substrates such as plastics, glass, or metals, the ink cartridge 10 is particularly advantageous because the use of sintered metal rather than a conventional polymer in the construction of the ink cartridge 10 allows for the use of a wider range of solvents. Generally speaking, in a conventional inkjet cartridge made of plastic or polymeric materials, it is necessary to use an ink having an aqueous solvent base rather than an organic solvent base. If an ink having an organic solvent base is used in such an ink cartridge 10, then the ink solvent tends to permeate the plastics used in the ink cartridge 10, causing the ink cartridge 10 to dissolve partially or otherwise be damaged.

[0043] According to the present disclosure, the body 12 and the lid 24 are formed of sintered metal that is impermeable to organic solvents such as alcohols, acetates, ketones, oils, hydrocarbon solvents, halogenated solvents, and lactones. Thus, these organic compounds can now be used as solvents in fluid formulations. This is particularly beneficial when printing on non-porous substrates because it has been found that this type of organic solvent-based fluid provides better penetration and adhesion to the printed non-porous substrate.

[0044] Reference is now made Figure 2 to FIG. 200, a flow chart depicting a method for forming a cartridge 10 in accordance with an embodiment of the present disclosure. As given in block 202, a metal precursor material is prepared. The metal portion of the precursor material can be any one or more of the materials described elsewhere herein. In some embodiments, the metal portion is mixed with an organic binder that allows the precursor material to retain its shape when pressed into the desired shape.

[0045] As given in block 204, the precursor material is formed into the desired shape of the side 18 and bottom 24 of the body 12. In one embodiment, this is accomplished by pouring a powdered or granular precursor material into a mold in the shape of the outer shell of the body 12 and then pressing an inner mold of the inner shape of the body 12 into the precursor material and the outer mold, thereby evenly distributing the precursor material in the space between the inner and outer molds. In some embodiments, the inner and outer molds are first positioned and then the precursor material is poured and pressed into the space between them.

[0046] Prior to removing the shaped precursor material from the mold, some type of treatment may be required on the precursor material to maintain the shape of the mold. This treatment can depend on the type of precursor material used. In some embodiments, as given in block 206, an initial heating step includes this initial treatment. In some embodiments, the initial treatment is a heating process in the absence of an oxidizing agent such as oxygen that volatilizes and removes the organic matter in the precursor material, thereby driving the organic matter away from the metal in the precursor material. This can be performed before or after removing the mold from the shaped form.

[0047] As given in block 208, a final heating step is performed where the metal particles in the retained shaped form are heated under conditions sufficient to cause the particles to flow together and produce a solid, unified sintered metal body 12 including sidewalls 18 and bottom 26. In various embodiments, this can also be performed before or after releasing the shaped body 12 from the mold. In some embodiments, the final heating step 208 is also performed in the absence of an oxidizing agent such as air. As given in block 210, in some embodiments a post-treatment step is performed where the shaped body 12 is subjected to one or more of cleaning, passivation, polishing, deburring, marking, or engraving as needed.

[0048] As shown in block 212, filter 34 is optionally inserted in or near nozzle 28, and the filter 34 is used in some embodiments to prevent particles that are too large to flow through the through holes of the chip 30 and the nozzle from passing through. As needed, depending on the application intended for the ink cartridge 10, as shown in block 214, a foam or other absorbent block 32 is placed in the reservoir 22 in the body 12. The absorbent block 32 is adapted to release a certain volume of fluid dispensed through the ink cartridge 10 in a controlled manner.

[0049] As shown in block 216, the flexible circuit 36 and the chip 30 are attached to the body 12 as a preform containing both elements or one first and then the other. As shown in block 218, the reservoir 22 is finally filled, and as shown in block 220, the lid 24 is attached. In various embodiments, as described elsewhere herein, the lid 24 is made of the same material as the body 12 and formed in the same manner, and can be attached to the body 12 in a variety of different ways.

[0050] As used herein, the phrase "at least one of A, B, and C" refers to all possible combinations of none or more than one of each of A, B, and C, but at least one A, or one B, or one C. By way of example, and not limitation: Ax1, Ax2 + Bx1, Cx2, Ax1 + Bx1 + Cx1, Ax7 + Bx12 + Cx113. It does not mean Ax0 + Bx0 + Cx0.

[0051] The foregoing description of the embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications and variations are possible in light of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to utilize the invention in various embodiments with various modifications suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with their fair, legal, and proper scope.

Claims

1. A fluid ejection cartridge, comprising a single-piece integrally formed body made of sintered metal, the body having an upper portion, a lower portion, side walls, and a bottom having nozzles, the body constituting a reservoir, The sintered metal is formed by pressing a precursor material including a metal and a binder into the shape of the body and heating the precursor material to transform the precursor material into the sintered metal.

2. The fluid ejection cartridge according to claim 1, wherein the body comprises at least one of the following: copper, copper alloy, ferritic steel, carbon steel, iron-copper steel, copper-infiltrated steel, copper steel, iron-nickel steel, nickel steel, low alloy steel, hardened steel, diffusion alloy steel, 300 series stainless steel, 400 series stainless steel, and soft magnetic alloy.

3. The fluid ejection cartridge according to claim 1, further comprising a lid disposed over the upper portion of the body and sealed to the sintered metal of the upper portion of the body.

4. The fluid ejection cartridge according to claim 1, further comprising a chip in fluid flow communication with the reservoir.

5. The fluid ejection cartridge according to claim 1, further comprising a filter disposed in the reservoir at the lower portion of the body.

6. The fluid ejection cartridge according to claim 1, further comprising a volume of ejectable fluid disposed within the reservoir.

7. The fluid ejection cartridge according to claim 6, wherein the ejectable fluid comprises at least one organic solvent selected from the group consisting essentially of alcohols, acetates, ketones, hydrocarbon solvents, halogenated solvents, and lactones, and is not a water-based solvent.

8. The fluid ejection cartridge according to claim 6, wherein the ejectable fluid comprises at least one organic solvent selected from the group consisting of methanol, ethanol, isopropyl alcohol, butanol, 1-methoxy-2-propanol, 2-butoxyethanol, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, benzene, toluene, xylene, hexane, petroleum, chloroform, diiodomethane, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, and γ-butyrolactone, and is not a water-based solvent.

9. The fluid ejection cartridge according to claim 6, wherein the ejectable fluid is printing ink and further comprises a pigment or a dye.

10. A method for manufacturing a sintered metal cartridge, the method comprising the steps of: Pressing a precursor material including a metal and a binder into the shape of a cartridge having side walls and a bottom having nozzles, and heating the precursor material to transform the precursor material into a sintered metal piece.

11. The method for manufacturing a sintered metal cartridge according to claim 10, wherein the heating step further comprises an initial heating step to remove the binder from the metal in the precursor material.

12. The method for manufacturing a sintered metal cartridge according to claim 10, wherein the heating step further comprises a final heating step to cause the metal to flow into the sintered metal piece.

13. The method for manufacturing a sintered metal ink cartridge according to claim 10, further comprising the step of post-treating the sintered metal part by at least one of the following: cleaning, passivation, polishing, deburring, marking, and engraving.

14. The method for manufacturing a sintered metal ink cartridge according to claim 10, further comprising the step of placing a filter into the sintered metal ink cartridge.

15. The method for manufacturing a sintered metal ink cartridge according to claim 10, further comprising the step of inserting a fluid absorbent block into the sintered metal ink cartridge.

16. The method for manufacturing a sintered metal ink cartridge according to claim 10, further comprising the step of attaching a flexible circuit and a chip to the sintered metal ink cartridge.

17. The method for manufacturing a sintered metal ink cartridge according to claim 10, further comprising the step of filling the sintered metal ink cartridge with a jetable fluid.

18. The method for manufacturing a sintered metal ink cartridge according to claim 10, further comprising the step of attaching a lid to the sintered metal ink cartridge.

19. The method for manufacturing a sintered metal ink cartridge according to claim 10, further comprising the step of attaching a lid to the sintered metal ink cartridge, wherein the lid is formed of the sintered metal.

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