Ink containment system for an ink-jet printer.

Abstract: The invented containment system (30; 130) provides a double-walled, or nested bag, configuration in which ink or liquid toner is contained within the sealed inner bag (44; 144) and the inner bag is contained, in turn, within a sealed outer bag (46; 146). An inlet/outlet port (42; 142) is provided for the introduction and extraction of ink into and out of the interior volume (V) formed by the nested bags (44, 46; 144, 146). In one embodiment, the sidewalls (32, 32') are formed separately and their peripheral edges are staked to either side of an annular frame member (38) formed integrally with the inlet/outlet port (42). In another embodiment, the sidewalls (144 a , 144 a '; 146 a , 146 a ') are sealingly joined directly to one another along their peripheries. Preferably, the inner bag (44; 144) or liner is a flexible mono polymer film or co-extrusion thereof that is ink-impermeable and the outer bag (46; 146) or liner is a flexible laminar structure including metallized polymer layers adhered to one another.

Description: Technical Field The present invention relates generally to ink containment systems for printers. More particularly, it concerns an improved ink containment system wherein a plural-walled ink-containing bag is formed of two opposing walls each of which is formed of separate, inner and outer, film layers joined along their peripheries and joinable to an inlet/outlet port or fitment. Background Art Typically, ink-containment systems for printers must provide for the secure containment of ink and for the introduction of ink thereinto and extraction of ink therefrom. Traditional constructions have been rigid, e.g. collapsible-rigid-wall structures, or compliant, e.g. collapsible-flexible-single-wall, structures of the so-called pillow design whereby opposing laminar sidewalls are joined along their peripheries to render a pillow-shaped ink container. Some of the drawbacks of such conventional ink-containment systems is volumetric inefficiency of the containment or the extraction whereby only a fraction of the container's nominal volume, e.g. only approximately 60%, is usable for containment and/or a significant volume of remnant ink is discarded with the container after maximum extraction. Another problem with laminar sidewall structures is that ink containment typically requires a metallization of the laminates, which sometimes leads to delamination due to ink or other harsh liquid contamination. The drawback to metallization in laminates is low adhesion to the adhesives used to bond the films, and susceptibility to ink and liquid toner attack. Thus, while metallization meets the requirements of strength and ink-, air- and gas-impermeability, it reduces the reliability of the containment. Such a containment is disclosed in FR-A-2 485 991. Laminar structures in general notoriously delaminate due to flexure and/or ink contamination. Once a sidewall structure has begun the delamination process, the process is irrevocably progressive. Further, laminar sidewall structures of a given thickness are inherently less flexible, simply because of the bonding of the laminar components over their substantial surface area, than two separate films of the same overall thickness. Thus, a single film used for ink or liquid toner containment, whether laminated or not, which has the same overall thickness tends to be stiffer and thus less efficient. Ink containers preferably resist leakage not only in normal use, but also when accidentally dropped. Rigid box-like containment structures tend to shatter or fracture when dropped, and flexible, single-walled, pouch-like containment structures tend to burst or puncture when dropped. None of the known prior art ink-containment structures provides for the secure containment of ink against the possibility of ink leakage during long-term storage, normal use or accidental shock or other trauma to the container. European Patent No. 561081 discloses an ink jet refill pack comprising a cartridge which has a hinge cover. The cartridge receives a refill having an internal ink containing bag and internal absorbent paper in an external bag which has an opening to receive excess ink from a printer. Only the refill is replaced. The absorbent paper holds ink so that the used refill is clean to handle. Disclosure of the Invention In a broad aspect, the invention provides a fluid-containment system for a printer, the system comprising: plural bags positioned in a nested configuration that allows movement of each bag relative to the other; and an inlet/outlet port structure connected with a periphery of said nested plural bags for the introduction of fluid into and out of a fluid-containment volume (V) defined thereby; and wherein said plural bags include a first inner bag formed from a flexible, chemically resistant, substantially-fluid-impermeable material defining said fluid-containment volume (V) therein and a second outer bag substantially enclosing said first inner bag in a substantially air and liquid tight fashion, said outer bag formed from a substantially-air-impermeable material. In one embodiment, the sidewalls are formed separately and their peripheral edges are staked to either side of annular frame member formed integrally with the inlet/outlet port. In another embodiment, the sidewalls are sealingly joined directly to one another along their peripheries. Preferably, the inner bag or liner is a flexible mono polymer film or coextrusion thereof that is ink-impermeable and the outer bag or liner is a flexible laminar structure including metallized polymer layers adhered to one another. These and additional aims and advantages of the present invention will be more readily understood after consideration of the drawings and the detailed description of the preferred embodiment which follows. Brief Description of the Drawings Fig. 1 is a fragmentary, isometric view of the invented ink-containment system made in accordance with a preferred embodiment. Fig. 2 is a cross-sectional view of the invented system, taken generally along the lines 2-2 of Fig. 1. Fig. 3 is a fragmentary, isometric view of the invented ink-containment system made in accordance with an alternative, preferred embodiment in which there is provided no chassis frame connection. Fig. 4 is a cross-sectional view of the invented system in its alternative embodiment, taken generally along the lines 4-4 of Fig. 3. Detailed Description of the Preferred Embodiment and Best Mode of Carrying Out the Invention In accordance with conventional ink-containment devices made with laminar sidewall construction, plural layers of different materials--each performing typically only one needed function, e.g. sealing, metallizing, strengthening or adhering--form a bonded film or sheet. Problems alluded to in the background section hereof include that of delamination and insufficient flexibility in such an ink-containment devices. Those of skill in the art will appreciate that metallization layers tend to form relatively weak bonds with other layers. Moreover, ink and liquid toner tend to attack rather harshly such layers, the result of which often is undesirable delamination over time. It will also be appreciated that the flexural modulus of a bonded, laminar structure is lower simply because of the nature of a laminate in which, over any arbitrarily short, longitudinal span of the laminate, there is less capacity of the laminate to flex or bend due to the inter-layer bonding of plural laminar components therein. Referring collectively to Figs. 1 and 2, the invented ink- or liquid toner-containment system is indicated generally at 30. Importantly, it may be seen that system 30 in accordance with a first preferred embodiment includes opposing sidewalls 32, 32', each including a generally coextensive inner layer and a separate outer layer, the sidewalls defining an ink- or toner-containment volume V. Thus, immediately it may be appreciated that the prior art laminar sidewall structure having the problems discussed above is avoided in accordance with invention. Preferably, sidewall 32 includes an inner layer 34 and an outer layer 36 preferably approximately coextensive therewith, with the peripheral edges of layers 34, 36 sealingly joined together. Similarly, sidewall 32' preferably includes an inner layer 34' and an outer layer 36' approximately coextensive therewith, similarly sealingly joined with one another. It will be appreciated that primed reference designators, e.g. 32', associated with unprimed reference designators, e.g. 32, as used herein, indicate opposing, and usually mirror-image, but otherwise identical components of systems 30, 130 (see Figs. 3, 4). As may be seen, a frame chassis member or armature 38 including a rectilinear annulus indicated generally at 38 a bonds opposing sidewalls 32, 32' along opposing, raised, annular shoulders 38 aa , thereby to complete a pocket-like enclosure or container 40 for the leak- and rupture-proof containment of ink or liquid toner. As will be seen, an alternative embodiment of the invented system includes no frame chassis armature 38, but instead effectively, directly joins opposing sidewalls 32, 32' at their peripheries, thereby to form a relatively free-standing, sealed pouch-like container 130 for corrosive or otherwise harsh printer liquid, e.g. for the containment of an ink-jet printer's ink or a laser printer's liquid toner. Referring still to Figs. 1 and 2, it may be seen that system 30 preferably also includes an inlet/outlet port 42, which may be integral with frame chassis armature 38, as indicated in the illustrated embodiment, or may be separate therefrom. Inlet/outlet port 42 will be understood to assume any desired configuration, within the scope of the invention, and its purpose of course will be understood to be to permit introduction of ink or liquid toner into, and to permit extraction of ink or liquid toner from within sealed container 40. It will be apparent that opposing double-walled sidewalls 32, 32' form what will be referred to herein as nested, inner and outer bags 44, 46. Ink or liquid toner may be introduced into or extracted from plural-bag containment system 30 in any suitable manner, as by the use of syringes, pumps, etc. A preferably removable, rigid outer shell 48 of any desired configuration may be provided for purposes of handling, etc. It may be seen perhaps better from Fig. 2 that the front side film layers have been staked along annulus 38 a partly to define a double-walled bladder for the containment of ink or liquid toner. Between the inner and outer film layers that define this front sidewall is a 1 atmosphere volume of air that acts as a shock absorber to reduce the possibility of rupturing the inner film layer that contains ink or liquid toner. It is believed that this double-walled construction provides an unprecedented level of security and reliability in ink or fluid toner containment. The invented system may be thought of as a redundant system, as its bag-in-bag structure provides two nested containment vessels so that if the inner bag should rupture, nevertheless the outer bag will still contain the ink or liquid toner. Turning now collectively to Figs. 3 and 4, an alternative preferred embodiment of the invention is indicated generally at 130. Ink- or liquid toner-containment system 130 may be seen to differ from system 30 in only one important respect: system 130 has no annulus or ring to which the sidewalls attach. Instead, in accordance with the alternative embodiment of the invention, the sidewalls are joined around their peripheral edges, or selvages, directly to one another. An inlet/outlet port 142 is provided and a protective shell 140 may be provided in this embodiment, within the scope of the invention. It will be appreciated that the pleats by which bag-in-bag system 130 tends to maintain its rectilinear shape preferably are in the base region, and thus are invisible. The invention may be described as a fluid-containment system. The invented system 130 in accordance with its preferred embodiment includes a first inner bag 144 including opposing generally coextensive flexible films 144 a , 144 a ' of fluid-impervious material defining a fluid-containment volume V therebetween; a second outer bag 146 substantially enclosing first inner bag 144 in a nested configuration--to produce a double-walled containment of ink or liquid toner--with outer bag 146 including opposing generally coextensive films 146 a , 146 a ' of impact-resistant material; and an inlet/outlet port structure 142 connected with a periphery of nested first and second bags 144, 146 for introduction of fluid into, and extraction of fluid out of, fluid-containment volume V. Preferably, the invented system further includes a mounting structure connected with the port structure, similar to that shown in Figs. 1 and 2, for mounting such nested first and second bags and port structure to the frame member of the printer. Although, as may be seen from Figs. 3 and 4, this feature is optional and a containment system without such mounting structure is within the scope of the invention. System 130 also may provide a protective outer shell 148. Preferably, the first bag includes an overlapped first selvage substantially defining its periphery, with the first selvage including a first joining structure that joins the layers of fluid-impervious material in opposition to form the inner bag. Similarly, the second bag includes an overlapped second selvage substantially defining its periphery, with the second selvage including a second joining structure that joins the layers of air-impervious material in opposition to form the outer bag. Such is better seen in Figs. 1 and 2, as in accordance with the alternative embodiment described above. The inner and outer bags each are formed of single continuous sheets of material. It will be appreciated that selvage is used herein in its broadest sense to refer to a peripheral edge of a material layer, e.g. a film or layer, for joining with a peripheral edge of another material layer. In accordance with a preferred embodiment of the invention, corresponding and lapping peripheral edges, or selvages, of opposing inner layers and overlapping outer layers that form the double-walled bag are suitably bonded to produce a sealed periphery of the bag for leak-proof and impact-resistant containment of a printer's ink or liquid toner. Preferably, the first joining structure includes a rigid annular structure interposing opposed flexible layers, as shown in Figs. 1 and 2. Opposed layers of the fluid-impervious material may be formed from a single folded or otherwise formed, e.g. vacuum molded, sheet of the material. Similarly, opposed layers of impact-resistant material may be formed from a single folded or otherwise formed, e.g. vacuum molded, sheet of the material. The opposing flexible layers may be staked, or otherwise sealingly joined to the annular structure by any suitable means involving elevated temperature and pressure, and may be staked one at a time or at the same time. It will be appreciated that the material from which is formed what will be referred to herein as inner bag 44, 144 must have the following properties: provides effective moisture-barrier, provides enough strength to resist rupture, flexible enough to stretch without breaking, and able to seal to high-density polyethylene (HDPE), the latter material being that from which the armature, fitment and inlet/outlet port preferably are made. Thus, in accordance with a preferred embodiment of the invention, the fluid-impervious material is chosen from a group including (1) low-density, linear low-density or ultra-low-density or single-site catalyst polyethylene (LDPE, LLDPE, ULDPE or SSCPE) or (2) co-extrusions thereof with core materials of bi-axially oriented nylon (BON) or ethyl vinyl alcohol (EVOH), e.g. co-extruded LLDPE/BON/LLDPE or LLPDE/EVOH/LLDPE, or polyvinylidene fluoride (PVDF). Such mono or co-extruded films as are used to form what will be referred to herein as the inner bag preferably are between approximately 1 and 3 mils thick. It will be appreciated that the material from which is formed what will be referred to herein as outer bag 46, 146 must exhibit the following properties: provide a moisture and air barrier, add strength further to resist rupture and to protect the inner bag, act as a redundant seal in case the inner bag breaks, and capable of sealing to HDPE and to the inner bag. Thus, also in accordance with a preferred embodiment of the invention, the impact-resistant material is a polymers/thin-metals laminate of bonded layers wherein the polymers are chosen from a group including preferably linear (the linear orientation will be understood positively to affect impact strength), low-density polyethylene (LLDPE), polyester (PET), BON and oriented polypropylene (OPP), and wherein the metals are chosen from a group including aluminum (Al) and silver (Ag). One such workable laminar structure (from innermost to outermost laminate) is LLDPE/PET-MET/MET-PET/LLDPE. Another (also from innermost to outermost laminate) is LLDPE/PET-MET/BON. Those skilled in the art will appreciate that the metallized polyester layers are preferably formed by vapor or sputter deposition of metal particles onto thin films of polyester, and that such metallized polyester layers act as excellent barriers to air and moisture. The layers of the laminar structure that form the outer films of the sidewalls may be bonded by any suitable adhesive. As may be seen in Figs. 3 and 4, the first and second bags 144, 146 preferably are configured at least in a base region thereof as a generally right parallelepiped, wherein the right parallelepiped configuration is nominally maintained at least in part by one or more pleats formed in the base region of the nested bags. Other pleating arrangements and configurations are contemplated, as are alternative methods of forming approximately right angles and corners, etc. in the double-walled bladder, and all are within the scope of the invention. Another way of understanding the invention is to think of it more simply as an ink- or liquid toner-containment system that includes, in accordance with a preferred embodiment thereof, a rigid armature including an annulus that defines an aperture and further including an inlet/outlet port; a first sidewall including an inner and an outer film joined on its periphery to a first side of the armature along the annulus, thereby to bound the aperture on a first side of the armature; and a second sidewall including an inner and an outer film joined on its periphery to a second side of the armature along the annulus, thereby to bound the aperture on a second side of the armature. It may be seen, then, that the first and second sidewalls and the annulus define a fluid-containment bladder having a predefined maximum internal volume V between the first and second sidewalls and within the aperture. It will also be appreciated that the choice of materials for the inner and outer films render the inner films flexible and substantially impervious to penetration by ink or liquid toner, and render the outer films flexible and substantially impervious to penetration by air or moisture. As described and illustrated herein, while the invented containment system is for use with a printer having a frame member, it preferably further includes mounting structure connected with the armature for mounting the armature to the frame member. In either embodiment, it will be appreciated that plural (e.g., two or more) nested bags may provide for redundant fluid contaminant. Industrial Applicability It may be seen, then, that the invented system has broad applicability in connection with ink- or liquid-toner-containment, and has more particular applicability to ink-jet or laser printers having replaceable ink supplies. Ink-containment systems made in accordance with the preferred embodiment of the invention have proven themselves reliably and securely to contain ink or liquid toner for extended periods of time, and have even survived a drop from an airplane. They also have been proven to yield more than approximately 90% of the ink contained therein, thus greatly increasing containment and extraction efficiency and reducing waste. Yet the invented system is inexpensively manufactured, e.g. by vacuum and/or injection molding. It will be appreciated that the invented system for ink or liquid toner containment may be manufactured using existing tools, dies and assembly processes and equipment. Accordingly, while the present invention has been shown and described with reference to the foregoing preferred embodiments, it will be apparent to those skilled in the art that other changes in form and detail may be made therein without departing from the scope of the invention as defined in the appended claims.

Claims: A fluid-containment system (30; 130) for a printer, the system comprising: plural bags (44, 46; 144, 146) positioned in a nested configuration that allows movement of each bag relative to the other; and an inlet/outlet port structure (42; 142) connected with a periphery of said nested plural bags (44, 46; 144, 146) for the introduction of fluid into and out of a fluid-containment volume (V) defined thereby; and wherein said plural bags (44, 46; 144, 146) include a first inner bag (44; 144) formed from a flexible, chemically resistant, substantially-fluid-impermeable material defining said fluid-containment volume (V) therein and a second outer bag (46; 146) substantially enclosing said first inner bag (44; 144) in a substantially air and liquid tight fashion, said outer bag (46; 146) formed from a substantially-air-impermeable material. The system of claim 1 wherein said nested configuration involves unbonded layering of said first inner bag (44; 144) within said second outer bag (46; 146). The system of claim 2 wherein said first inner bag (44; 144) is formed of unlaminated plural films. The system of claim 2 wherein said second outer bag (46; 146) is formed of laminated, plural films. The system of claim 3 wherein said second outer bag (46; 146) is formed of laminated, plural films. The system of claim 1, wherein said first inner bag (44; 144) includes opposing generally coextensive flexible films of fluid-impermeable material defining a fluid-containment volume (V) therebetween and wherein said second outer bag (46; 146) includes opposing generally coextensive flexible films (46 a , 46 a '; 146 a , 146 a ') of air-impermeable material. The system of claim 6, wherein said fluid-impermeable material is chosen from a group including low-density polyethylene or co-extrusions thereof and polyvinylidene fluoride. The system of claim 6,wherein said air-impermeable material is a polymers/thin-metals laminate of bonded layers wherein the polymers are chosen from a group including low-density polyethylene, polyester and nylon, and wherein the metals are chosen from a group including aluminum and silver. The system of claim 6, wherein said fluid-impermeable material is chosen from a group including low-density polyethylene or co-extrusions thereof and polyvinylidene fluoride and wherein said air-impermeable material is a polymers/thin-metals laminate of bonded layers wherein the polymers are chosen from a group including low-density polyethylene, polyester and nylon, and wherein the metals are chosen from a group including aluminum and silver. The system of claim 7, wherein said fluid-impermeable material is chosen from a group including low-density polyethylene or co-extrusions thereof and polyvinylidene fluoride and wherein said air-impermeable material is a polymers/thin-metals laminate of bonded layers wherein the polymers are chosen from a group including low-density polyethylene, polyester and nylon, and wherein the metals are chosen from a group including aluminum and silver.

Inventors: EDWARD S CAI, OLSEN DAVID, EDWARD S.CAI, OLSEN, DAVID
Applicants: HEWLETT PACKARD CO, HEWLETT-PACKARD COMPANY
Application year: 1998
Main classification: B41J2
IPC codes: B41J2