This disclosure relates generally to machines that move thermally treated fluid from a supply through a conduit to a printhead.
The word “printer” as used herein encompasses any apparatus, such as a digital copier, book marking machine, facsimile machine, multi-function machine, etc., that produces an image with a colorant on recording media for any purpose. Printers that form an image on a surface of an image receiving member and then transfer the image to recording media are referenced in this document as indirect printers. Indirect printers typically use intermediate transfer, transfix, or transfuse members to facilitate the transfer and fusing of the image from the image receiving member to the recording media. In general, such printing systems typically include a colorant applicator, such as a printhead, that forms an image with colorant on the image receiving member. Recording medium is fed into a nip formed between the surface of the image receiving member and a transfix roller to enable the image to be transferred and fixed to the print medium so the image receiving member can be used for formation of another image.
In ink imaging systems having intermediate image receiving members, ink is loaded into the system and delivered through a conduit system as liquid ink to a printhead for jetting onto a surface of an image receiving member. The ink can be in the form of aqueous ink, pigment and dye resin based aqueous ink, MICR ink, UV ink, and solid ink. When the ink is solid phase change ink, the solid phase change ink is transported through a feed chute by a feed mechanism for delivery to a melting device. The melting device heats the solid ink so it melts and then is delivered through the conduit system. Regardless of the ink type, once in the conduit system, the liquid ink is maintained at a temperature that enables ejection of the ink by the inkjet ejectors in the printhead, while preserving sufficient tackiness to enable the ink to adhere to the surface of the image receiving member. Accordingly, to transport the liquid ink, the conduit system must be essentially comprised of a material which does not facilitate adhesion or congealing of the liquid ink. Additionally, because the liquid ink is heated to a high temperature, chemical reactions between the ink and the conduit system are able to occur more readily. Conduit systems for liquid ink delivery that address these issues are desirable.
A conduit has been developed that transports liquid ink while attenuating or preventing chemical reactions with the conduit or substances seeping through the conduit. The conduit includes a body having a first end and a second end and a lumen extending through the body between the first end and the second end. The body is essentially comprised of a first material that is non-reactive with liquid ink. A first coating is applied to a surface of the body, and the first coating is essentially comprised of a second material that is impermeable to oxygen.
An ink umbilical assembly has been developed that transports liquid ink while attenuating or preventing chemical reactions with the assembly or substances seeping through a conduit in the assembly. The ink umbilical assembly includes a plurality of conduits essentially comprised of a first material that is non-reactive with liquid ink. The plurality of conduits has an outer surface. A coating is applied to the outer surface of the plurality of conduits, and the coating is essentially comprised of a second material that is impermeable to oxygen.
An inkjet printer has been developed that transports liquid while attenuating or preventing chemical reactions with a conduit in the printer or substances seeping through the conduit in the printer. The printer includes a printhead having a plate with a plurality of openings, a plurality of ink reservoirs, and an ink umbilical assembly. The ink umbilical assembly is configured to transport liquid ink from the plurality of ink reservoirs to the printhead. The ink umbilical assembly includes a plurality of conduits essentially comprised of a first material that is non-reactive with liquid ink. The plurality of conduits has an outer surface, and each conduit of the plurality of conduits has a first end configured to be coupled to the an ink reservoir of the plurality of ink reservoirs and a second end configured to be coupled to an opening of the plurality of openings. A first coating is applied to the outer surface of the plurality of conduits, and the coating is essentially comprised of a second material that is impermeable to oxygen.
The foregoing aspects and other features of a conduit and an ink umbilical assembly for use in an inkjet printer to transport liquid ink are explained in the following description, taken in connection with the accompanying drawings.
By way of example, a phase change ink printer 10 includes a liquid ink delivery system of the prior art as shown in
Each reservoir 14A, 14B, 14C, and 14D is configured to collect and retain liquid ink of a single color. As shown in
The liquid ink in the staging areas 22A1-4, 22B1-4, 22C1-4, and 22D1-4 is pressurized to facilitate delivery of the ink to a printhead 18A, 18B, 18C, or 18D. When a printhead 18A, 18B, 18C, or 18D needs additional ink, a valve is opened to enable ink from the respective staging area 22A1-4, 22B1-4, 22C1-4, or 22D1-4 to flow through the respective conduit 26A1-4, 26B1-4, 26C1-4, or 26D1-4 to the respective printhead 18A, 18B, 18C, or 18D. Accordingly, each printhead 18A, 18B, 18C, and 18D receives ink from each of the four reservoirs to enable each printhead to eject all four colors of ink, namely, black, cyan, magenta, and yellow.
The spatial relationships between the reservoirs 14A, 14B, 14C, and 14D and the printheads 18A, 18B, 18C, and 18D are not accurately depicted in the block diagram shown in
Accordingly, to address these and other issues, as well as to provide conduits that are flexible and are attached to one another to allow relative motion for printer operation and reasonable service access, an ink umbilical assembly, such as the ink umbilical assembly 100 shown in
The ink umbilical assembly 100 shown in
Each of the conduits 130A-D and 138A-D are substantially similar to one another. Turning now to
The first end 144 is coupled to one of the reservoirs 14A, 14B, 14C, or 14D (shown in
More specifically, ink is essentially comprised of specific chemicals to produce ink material having predetermined properties suited to the printing process. Chemicals added to the ink to result in predetermined properties are also known as additives. For example, some phase change inks are formulated with additives to cause the ink to have a predetermined melting temperature. Additionally, some inks are formulated with additives to cause each color of ink to have a predetermined hue. Additionally, some inks are formulated with additives to cause the ink to have a predetermined viscosity and tackiness such that the ink flows through the printing system and adheres to the print media. For example, the additive Sylvalite is added to ink to cause the ink to have a predetermined viscosity and tackiness when it is heated to a predetermined temperature. Some additives have chemical properties which make them more reactive or less reactive with other chemicals. For example, Sylvalite is reactive with oxygen such that exposure of Sylvalite to oxygen at an elevated temperature causes Sylvalite to oxidize, thereby changing the chemical and physical properties of the ink. Additionally, some additives are more difficult or less difficult and more expensive or less expensive to produce. Accordingly, the additives added to ink to cause the ink to have predetermined properties are selected based on their chemical properties as well as their cost.
Similarly, conduits are essentially comprised of specific chemicals that provide the conduit with predetermined properties suited to the printing process. For example, some conduits are essentially comprised of a material formulated with specific chemicals such that the conduits are non-reactive with the heated, liquid ink. Conduits can be essentially comprised of materials formulated with specific chemicals to make the conduit bodies non-reactive with additives included in the heated, liquid ink; impermeable to oxygen and other gases such as carbon dioxide; flexible; reduce the likelihood that the ink does not adhere to or congeal within the lumen; and impermeable to ink pigments or dyes. One or more of the specific chemicals can be used together or separately to impart one or more of these properties to the conduit provided the chemicals do not react adversely with one another. As used herein, ink pigments or dyes are colorant materials added to ink to impart a particular color hue to the ink.
To illustrate the importance of formulating the ink and the conduits with compatible materials, in one embodiment, by way of example, the first material of the conduits is essentially comprised of silicone and the ink includes the additive Sylvalite. Silicone is a desirable material to use for the first material of conduits because it produces conduits that are substantially flexible, that do not facilitate adhesion or congealing of the liquid ink within the lumen, and that are non-reactive with a large variety of chemicals, including Sylvalite. However, silicone is also highly permeable to oxygen. In alternative embodiments, perfluorinated ethers and perfluorinated hydrocarbon elastomers can be used for the first material of conduits. Sylvalite is a desirable chemical to use as an additive in phase change ink because it produces ink with a predetermined viscosity and tackiness at an elevated temperature and because it is inexpensive. However, Sylvalite is also reactive with oxygen such that exposure to oxygen at elevated temperatures changes the chemical and physical properties of the Sylvalite. Accordingly, when liquid ink including Sylvalite passes through the conduits essentially comprised of silicone, the Sylvalite does not react with the silicone in the conduits, but oxygen passes through the conduits and oxidizes the Sylvalite, thereby changing the chemical and physical properties of the ink. Accordingly, as described in more detail below, exemplary conduits further include at least one coating applied to the external surfaces. While the conduits can be used with a variety of ink types, they are especially useful for transporting melted phase change inks as these inks have additives that can be reactive than those found in other inks and the ink and additives are heated and maintained at temperatures that encourage chemical reactions.
Shown in
More specifically, the conduit 130A′ is rendered suitable for transporting inks including additives prone to oxidization. The ink including the oxidization prone additive does not react with the non-reactive first material 154 in the conduit 130A′ and the oxygen impermeability of the second material 172 of the first coating 168 prevents oxygen from passing through the conduit 130A′ thereby reducing the risk that the additive oxidizes. Accordingly, the first coating 168 increases the versatility of the conduit 130A′ by rendering it suitable for transporting a greater variety of inks including inks having oxidization prone additives, some of which are relatively low cost additives.
In at least one embodiment, the first coating 168 is integrally formed with, rather than being applied to, the external surface 160 of the conduit 130A′. Integrally forming the first coating 168 with the external surface 160 achieves the same result as applying the first coating 168 to the external surface 160, but results in a single unitary piece essentially comprised of a homogenous material. This integration of the two materials is advantageous for ease of production of the ink umbilical assembly. In at least one embodiment, the homogenous material is polyvinylidene fluoride.
Shown in
More specifically, the conduit 130A″ is rendered suitable for transporting liquid inks including additives prone to oxidization and pigments or dyes prone to migration through materials. The ink including the oxidization prone additive and migration prone pigments or dyes does not react with the non-reactive first material 154 in the conduit 130A″ and the oxygen impermeability of the second material 172 of the first coating 168 prevents oxygen from passing through the conduit 130A″ thereby preventing exposure of the oxidization prone additive to oxygen. Additionally, the pigment or dye impermeability of the third material 180 of the second coating 176 prevents pigments or dyes from passing through the conduit 130A″ thereby reducing the risk of migration of the pigments or dyes out of the ink and/or into other adjacent conduits. Accordingly, the second coating 176 increases the versatility of the conduit 130A″ by rendering the conduit 130A″ suitable for transporting a greater variety of inks including inks having oxidization prone additives and having migration prone pigments or dyes, some of which are relatively low cost additives.
In this embodiment, the first coating 168 is interposed between the second coating 176 and the external surface 160 of the conduit 130A″. This arrangement allows oxygen to permeate from outside the ink umbilical assembly 100 (shown in
In at least one embodiment, the second coating 176 is integrally formed with, rather than applied to, the first coating 168. Integrally forming the second coating 176 with the first coating 168 achieves the same result as applying the second coating 176 to the first coating 168, but results in a single unitary piece. This is advantageous for ease of production of the ink umbilical assembly 100 (shown in
Shown in
In at least one embodiment, the first coating 168 is integrally formed with, rather than applied to, the second coating 176. Integrally forming the first coating 168 with the second coating 176 achieves the same result as applying the first coating 168 to the second coating 176, but results in a single unitary piece. This is advantageous for ease of production of the ink umbilical assembly. The first coating 168 is able to be integrally formed with the second coating 176 whether the second coating 176 is applied to or integrally formed with the conduit 130A′″.
In at least one alternative embodiment, the conduit 130A, 130A′, 130A″, or 130A′″ includes an additional coating or a number of additional coatings. An additional coating is essentially comprised of materials having additional properties suited to the printing process. In at least one other alternative embodiment, a coating or number of coatings, for example first coating 168 and second coating 176, are applied to the internal surface 156 of the conduit 130A, 130A′, 130A″, or 130A′″ rather than the external surface 160. In this alternative embodiment, the coating(s) applied to the internal surface 156 are non-reactive with a large variety of chemicals and do not facilitate adhesion or congealing of the liquid ink.
It will be appreciated that some or all of the above-disclosed features and other features and functions or alternatives thereof, may be desirably combined into many other different systems, apparatus, devices, or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art, which are also intended to be encompassed by the following claims.