MX2008008107A - Filter/wicking structure for micro-fluid ejection head - Google Patents

Abstract

A micro-fluid ejection head structure and a method for assembling a micro- fluid ejection head structure. The micro-fluid ejection head structure includes a molded, non-fibrous wicking and filtration structure. The wicking and filtration structure is fixedly attached to a filtered fluid reservoir of the micro-fluid ejection head structure for flow of filtered fluid to a micro-fluid ejection head attached to the head structure.

Description

FILTRATION STRUCTURE / ABSORPTION BY PABILO FOR MICRO-HEAD OF FLUID EXPULSION FIELD OF THE INVENTION The description refers to fluid micro-ejection heads, and in particular to fluid supply devices and improved filtration for fluid micro-ejection.

BACKGROUND OF THE INVENTION The fluid ejection micro-heads are useful for ejecting a variety of fluids including Lint.as, cooling fluids, drugs, lubricants and the like. A widely used fluid ejection micro-head is in an inkjet printer. Inkjet printers continue to improve as the technology to make micro-heads fluid ejection continues to advance. Constantly new techniques are developed to provide low cost and very reliable printers which are close to the speed and quality of laser printers. An additional benefit of inkjet printers is that color images can be produced at a fraction of the cost of laser printers with such good quality or better than laser printers. All of the previous benefits that inkjet printers presented have also increased the competitiveness of suppliers to offer comparable printers and supplies for such printers more cost-effectively than their competitors. SUMMARY OF THE INVENTION The fluid ejection micro-devices can be provided with permanent, semi-permanent, or replaceable ejector heads. Since the ejection heads require unique and relatively expensive manufacturing techniques, some ejection devices are provided with permanent ejector heads or semipermanent.es. With the intent to prot.eger the ejector heads for long-term use, filtration structures are used between a fluid supply cartridge and the ejection heads to remove particles that may clog the microscopic fluid circulation path in the heads of expulsion. Conventional filtration structures include multiple components that must be assembled accurately to a filtrate fluid reservoir adjacent to an ejection head. Due to the multiple components required for the filtration structures, the cnsamblcje of the structures is time consuming and requires relatively wide manufacturing tolerances.

In view of the above the exemplary embodiments of the description provide a micro-head structure for fluid ejection and a method for the assembly of a micro-head structure for fluid ejection. The micro-head structure of fluid ejection included a molded structure of filtration and absorption by non-fibrous wicking. The wicking filtration and absorption structure is fixedly coupled to a filtrate fluid reservoir of the fluid ejection micro-head structure for the circulation of the filtered fluid to a fixed fluid ejection micro head to the head structure. Another exemplary embodiment of the decipherment provides a method for assembling a fluid ejection micro-head structure for a fluid supply cartridge. The method includes providing a molded structure of filtration and absorption by non-fibrous wicking. The wicking filtration and absorption structure is fixedly coupled to a filtered fluid reservoir of the fluid ejection micro-head structure for the ci culation of the filtered fluid from a supply cartridge to a fixed fluid ejection micro-head. to the head structure. Still in another exemplary embodiment of the description provides a fluid supply cartridge holder. The fluid supply cartridge holder includes a permanent or semi-permanent fluid ejection micro-head structure. The ejection head structure contains a micro-head for fluid ejection, a deposit of filtered fluid in fluid circulation communication with the fluid ejection micro-head, and a wicking filtration and absorption structure fixedly coupled to the filtered fluid reservoir for the flow of filtered fluid to the fluid reservoir filtered out. The structure of filtration and absorption by wick includes a molded element of filtration and absorption by non-fibrous wick. An advantage of the exemplary embodiments described in the present invention is that a unitary component can be used in place of multiple components to provide comparable or better protection of the fluid ejection micro-heads. The use of a unitary component eliminates several of the steps required to assemble a wicking filtration and absorption structure to a fluid reservoir of a fluid ejection micro-head structure. The unit component also reduces the stacking tolerance compared to the tolerance stack of a multi-part component since the unit component is specified for a single tolerance.

BRIEF DESCRIPTION OF THE FIGURES More features and advantages of the modalities described by reference to the detailed description when they are considered together with the figures, which are not to scale, where similar reference numbers show similar elements through various views will be apparent. : Figure 1 is a top perspective view, not to scale, of a fluid supply cartridge and therefore cover; Figure 2 is a bottom perspective view, not to scale, of a fluid supply cartridge and fluid outlet port therein; Figure 3 is a perspective view, not to scale, of a multi-cartridge holder containing multiple cartridges for a fluid ejection micro-device; Figure 4 is a cross-sectional view, not to scale, of a fluid supply cartridge containing a negative pressure induction device therein and a portion of a fluid ejection micro-head structure for connection to the cartridge fluid supply; Figure 5 is a schematic sectional view, not to scale, of a portion of a micro-head structure for fluid ejection; Figure 6 is a schematic sectional view, not to scale, of a portion of a fluid ejection micro-head structure according to one embodiment of the disclosure; and Figure 7 is a cross-sectional view, not to scale, of a fluid supply cartridge containing a negative pressure induction device therein and a portion of a fluid ejection micro-head structure according to the description for connection to the fluid supply cartridge.

DETAILED DESCRIPTION OF THE INVENTION Referring to Figures 1 and 2, perspective views of a fluid cartridge 10 are illustrated. The fluid cartridge 10 includes a rigid body 12 and a cover 14 coupled to the body 12. The cover 14 may include an inlet port. 16 to fill or refill the body 12 with fluid such as ink.

In Figure 2 a lower perspective view of the fluid cartridge 10 is provided. A fluid outlet port 18 is provided for fluid flow out of the fluid cartridge 10 to a fluid ejection micro-head structure described in more detail below. The fluid cartridge 10 may also include a substantially transparent panel 10 for detecting the presence of liquid in the fluid cartridge 10.

The rigid body 12 and the cover 14 of the fluid cartridge 10 include can be made from a variety of materials, including but not limited to, metals, plastics, ceramics, and the like, so long as they are made of materials compatible with the fluids that they contain. In that regard, a polymeric material can be selected which can be used to provide the body 12 and the cover 14 of a group consisting of an amorphous thermoplastic polyetherimide available from G.E. Plastics of Huntersv, North Carolina, a thermoplastic polyethylene terephthalate resin filled with glass available from E.l. du Pont, of Nemours and Company of Wilmington, Delaware, a sindiotactic polystyrene? containing fiberglass available from Dow Chemical Company of Midland, Michigan, a blend of high impact polystyrene / polyphenylene oxide resins available from G.E. Plastics, and a polyphenylene ether / polymethylene resin available from G.E. Plastics When permanent or semi-permanent ejector heads are used, the ejection heads can be attached to a multiple fluid cartridge holder 22 (Figure 3). The support 22, shown in Figure 3, includes multiple slits for replaceable fluid cartridges.

In Figure 4 a cross-sectional view of a fluid cartridge 10 and ejection head structure 24 containing an ejection chip 26 is illustrated. The ejection head structure 24 can be fixedly or detachably coupled to support 22. The structure of ejection head 24 includes a wicking filtration and absorption component 28 which is collected to a filtered fluid reservoir 30 from the ejection head structure 24.

As shown in Figure 4, the fluid cartridge 10 may have two compartments therein, a liquid compartment 32 and a cavity containing negative pressure producing material 34. A liquid circulation path 36 is provided between the compartment liquid 32 and cavity containing material that produces negative pressure 34. The cavity containing material that produces negative pressure 34 may contain a device that induces negative pressure 38 tai as a felted foam. For the purpose of this description, a wide variety of devices can be used which induces negative pressure 38 as long as the device is in close contact with a fluid outlet wick 40 when a fluid cart 10 is coupled to the structure of the fluid. fluid ejection micro-head 24. Such negative pressure inducing devices 38 may include, but are not limited to, open cell foams, felts, capillary-containing materials, absorbent materials, and the like.

As used herein, the terms "foam" and "felt" means that generally refer to open-celled foams or crosslinked with voids intorconectados, ie, porosity and permeability, of the configuration desired which allows that a fluid is retained within the foam or felt and to flow therethrough at a desired rate for delivery to the fluid ejection microchip 26. Fuses and felts of this type are typically made of polyether materials. polyurethane by methods well known in the art. A commercially available example ele appropriate foam is an open cell foam felted which is a material ele polyurethane by polymerizing ele a polyol and tolylene diisocyanate, the resulting foam is a pol Flexible Iester compressed and reticulated compressing a foam with both pressure and heat to the specified thickness.

With reference to Figure 5, a schematic, non-scale view of a wicking filtration and wicking component 28 is illustrated. The wicking filtration and wicking component includes a filter cover 42 which is fixedly attached to the side walls 44 of the filtered fluid reservoir such as by adhesive, laser welding, ultrasonic welding, thermal stacking, and the like. A filter 46 which can be made of plastic mesh or wire mesh 46 is thinned to the filter cover 42 either by thermal stacking or by laser welding. A wicking deposit 48 on the filter cap 42 is then pressed and the wick 40 pressurized inside the wicking absorption tank 48 to provide the wicking absorption component 28.

Each of articles 40, 42, 46, and 48 of the wicking filtration and absorption component 28 has a manufacturing tolerance. Therefore, the sum of the manufacturing tolerances of each of articles 40, 42, 46, and 48 provides the general fabrication tolerance of the wicking filtration and absorption component 28.

Those skilled in the art will readily recognize that the invention is not limited to the illustrated embodiment. For example, in an alternative embodiment, a plurality of the filtered fluid reservoirs can be covered with a single cap, and four or more filtration and wicking structures can be placed in said cap.

As illustrated in Figures 3 and 4, when the cartridge 10 is placed in the holder 22, the wicking filtration and absorption component 28 is placed through the fluid outlet port 18 so that the wick 40 is in contact with the liquid. circulation of fluid close to the device that induces negative pressure 33 in the cavity 34 of the cartridge 10. As the fluid is expelled by the ejection chip 26, the fluid is caused to re-fill the fluid reservoir 30 by circulation from the inducing negative pressure device 38 through the wick 40 and the filter 46. a conventional wick 40, therefore, it is composed of interwoven capillary paths, for example, polyolefin fibers felted t.al as polyethylene or polypropylene fibers.

With reference to Figures 6 and 7, an improved wicking filtration and absorption device 50 is illustrated. The device 50 includes a filter cap 52 and an integrally formed non-fibrous wicking filtration and absorption component 54 which provides a considerably unitary wicking filtration and absorption device. The non-fibrous wicking filtration and absorption component 54 formed can be provided by a hydrophilic, pore-porous substrate made of a polyester or polyolefin material. Such a polymeric material may include sintered thermoplastic particles that provide a nominal pore size therein ranging from about 5 to about 50 microns.

In an alternative embodiment, the wicking filtration and absorption component 54 of the device 50 may include a plurality of porosity zones therein, e.g., a wicking absorption zone and a filtration zone having different nominal pore sizes. . Such wicking filtration and absorption components are available from Porex Corporation of Fairourn, Georgia and can be made according to one or more of the Patents of E. ü. A. No. 5,432,100 and 6,030,558 Smith, et al.

The attachment of the filtration and wicking device 50 to the side walls 40 of the filter fluid reservoir 30 can be achieved by a variety of techniques including, but not limited to, laser welding, thermal stacking, ultrasonic welding, adhesives, and similar. Since an essentially unitary device 50 is provided, only one step is required to couple the wicking filtration and absorption device 50 to the fluid ejection micro-head structure 24. In contrast, in the filtration and absorption devices by At last, at least four assembly steps were required to couple the filtration and wicking device to the micro-head structure for fluid ejection.

In addition, since the components 52 and 54 of the wicking filtration and absorption device 50 are integrally formed to provide the essentially urinary device 50, only a small manufacturing tolerance is required for the device 50 in general. Therefore, manufacturing tolerances for the wicking filtration and absorption device 50 can be considerably lower than the combined manufacturing tolerances for the existing wicking and filtration components.

Referring now to Figures 3 and 7, when the cartridge 10 is placed in the holder 22, the wicking filtration and absorption device 50 is placed through the fluid outlet port 18 so that the filtration and absorption component by wick 54 is in contact) of fluid circulation close to the device that induces negative pressure 38 in the cavity 34 of the LO cartridge. As the fluid is expelled by the ejection chip 26, the fluid is caused to refill the fluid reservoir 30 by circulation from the device inducing negative pressure 38, through the wicking filtration and absorption component 54.

Having described various aspects and modalities of the description and some advantages thereof, it will be recognized by those skilled in the art that the modalities are prone to various modifications, substitutions and revisions within the spirit and scope of the appended claims.

Claims (5)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following is claimed as a priority: CLAIMS 1. - A fluid ejection micro-head structure comprising a molded structure of non-fibrous wicking filtration and absorption fixedly attached to a fluidized fluid reservoir of the fluid ejection micro-head structure for circulation of the fluid. fluid filtered to a micro-chip for ejection of fluid coupled to the head structure.
2. 2. The fluid ejection micro-head structure according to claim 1, characterized in that the wicking filtration and absorption structure comprises a hydrophilic polymeric porous substrate, and a filter cover molded to the porous substrate to provide a unitary cover, to the filtration structure absorption per wick.
3. 3. The fluid ejection micro-head structure according to claim 1, characterized in that the wicking filtration and absorption structure comprises a hydrophilic polymeric porous substrate, having one or more different porosity zones. inside it.
4. 4. The fluid ejection micro-head structure according to claim 1, characterized in that the wicking filtration and absorption structure comprises a polyester, polypropylene, polyethylene, or PET material.
5. 5. The fluid ejection micro-head structure according to claim 1, characterized in that the wicking filtration and absorption structure is fixedly coupled to the filtered fluid container by a method selected from the group consisting of laser welding. , ultrasonic welding, and thermal stacking. 6. - The fluid ejection micro-head structure according to claim 1, characterized in that the wicking filtration and absorption structure is adhesively coupled to the filtered fluid reservoir. . - The fluid ejection micro-head structure according to claim 1, characterized in that the wicking filtration and absorption structure comprises sintered thermoplastic particles that provide a nominal pore size ranging from approximately b to approximately 50 microns. 8. - A method for assembling a micro-head structure for fluid ejection for a fluid supply carton, the method comprising the steps of: providing a structure of filtration and absorption by non-fibrous molded wick; and firmly attaching the filtration and wicking structure to a filtered fluid reservoir of the fluid ejection micro-head structure for the flow of filtered fluid from a supply cartridge to a micro-chip fluid ejection coupled to the fluid. head structure. 9. The method according to claim 8, characterized in that the wicking filtration and absorption structure comprises a hydrophilic polymeric porous substrate, and a molded filter cover, a porous substrate to provide an integrated lid, to the filtration structure and wicking absorption. 10. The method according to claim 9, characterized in that the filter cover is fixedly coupled to the filtered fluid container by a method selected from the group consisting of laser welding, ultrasonic welding, and thermal stacking. 11. The method according to claim 9, characterized in that the filter cover is fixedly coupled to the filtered fluid container by the use of an adhesive. 12. The method according to claim 8, characterized in that the wicking filtration and absorption structure comprises a hydrophilic polymeric porous substrate, having one or more zones of different porosity therein. 13. The method according to claim 8, characterized in that the structure of filtration and absorption by wick comprises a polyester, polypropylene, polyethylene, or PET material. 14. The method according to claim 8, characterized in that the wicking filtration and absorption structure comprises sintered thermoplastic particles that provide a nominal pore size ranging from about 5 to about 50 microns. 15. A fluid supply reservoir support comprising a fluid ejection micro-head structure made by the method of claim 8. 16.- A fluid supply cartridge for a fluid ejection micro-head that It comprises a fluid ejection micro-head structure made by the method of claim 8. 17. - A fluid supply cartridge holder comprising a permanent or semi-permanent fluid ejection micro-head structure, the ejection head structure comprising a micro-chip for fluid ejection, a fluid reservoir filtered in circulation communication of fluid with the micro-chip of expulsion of fluid, and a structure of filtration and absorption by wick fixedly fixed to the tank of filtered fluid for the circulation of filtered fluid to the tank of filtered fluid, where the structure of filtration and absorption by wick It comprises a filtering and absorption element by non-fibrous molded wick. 18. The fluid supply cartridge holder according to claim 17, characterized in that the wicking and filtering structure comprises a filtering and absorption element by hydrophilic polymeric porous wick and a filter cover molded to the element. of filtration and absorption by wicking to provide a unitary Lapa, to the structure of filtration and absorption by wicking. 19. The fluid supply cartridge holder according to claim 1"-", characterized in that the wicking filtration and absorption element comprises a hydrophilic polymeric porous substrate, having at least two different porosity zones within the 20. The fluid supply cartridge support according to claim 17, characterized in that the wicking filtration and absorption structure is fixedly coupled to the filtered fluid container by a method selected from the group consisting of Laser welding. , ultrasonic welding, and thermal stacking.