Method for recycling ink cartridge used for recording apparatus

A method, for recycling an ink cartridge used for a recording apparatus, comprises the steps of: discharging residual ink from an ink cartridge wherein a porous member is retained for the absorption of ink; using a cleansing fluid to clean the porous member; discharging the cleansing fluid from the porous member; and impregnating the porous member with ink.

BACKGROUND OF THE INVENTION
 The present invention relates to a recycling technique of an ink cartridge
 for an ink-jet recording apparatus, in which the resupply of ink is
 effected by the replacement of the cartridge. The present invention is
 particularly applicable, but not limited to, an ink-jet recording
 apparatus of a type in which an ink-jet recording head and an ink
 cartridge are mounted on a carriage.
 An ink-jet recording apparatus is known in which an ink container is
 attached to a carriage having an ink-jet recording head mounted thereon.
 In order to prevent printing failures associated with water head pressure
 change and air bubble generation due to agitation of ink by the carriage
 movement, it is preferable to accommodate a porous member at least in an
 ink supply port of the ink container, as disclosed in European Patent
 Publication No. 581531.
 This arrangement can solve the above-mentioned problems linked with the ink
 agitation since the ink is supplied to the recording head via the porous
 member.
 The recycling of ink cartridges is a desirable objective, and is in
 consonance with the current trend of effectively conserving resources and
 reducing the amount of pharmaceutical agents that are discharged to the
 environment. Japanese Unexamined Patent Publication No. Hei 7-60979
 discloses an ink cartridge recycling apparatus having an annular member
 provided with a rotatable ink chamber. An ink cartridge is mounted on the
 annular member so that the ink supply port faces outward while an ink
 supply tube is connected to a lid side of the ink cartridge, and then the
 annular member is rotated in that state.
 This apparatus makes it possible to fill new ink into a collected ink
 cartridge while discharging the remaining old ink from the collected ink
 cartridge using centrifugal force produced by the rotation of the annular
 member.
 This apparatus, however, suffers from a problem in that the size of the
 apparatus is large because centrifugal force must be employed. Further,
 ink may not be completely discharged by the centrifugal force because of
 strong capillary attraction originating in the porous member contained in
 an ink cartridge, and/or because of solidification or increased viscosity
 of the ink. Consequently, refilled new ink is mixed with old ink to lower
 printing quality, and this is a serious problem, in particular, in case of
 ink cartridges for color printing.
 It is conceivable to remove the porous member from the cartridge and then
 clean the cartridge sufficiently. The disassembly and the reassembly of
 cartridge is, however, required to increase the cost.
 SUMMARY OF THE INVENTION
 Therefor, an objective of the present invention is to provide a method for
 recycling an ink cartridge, which does not require the disassembly of an
 ink cartridge and which can provide a refilled ink cartridge ensuring high
 quality printing.
 In the method of the present invention, a porous member in an ink cartridge
 is cleansed by cleansing fluid. Further, the cleansing fluid is discharged
 from the porous member. Therefore, new ink is neither mixed with residual
 ink nor cleansing fluid. The ink cartridge, after recycling, can provide
 the same quality as a brand-new cartridge.
 Preferably, a method for recycling an ink cartridge for a recording
 apparatus according to the present invention comprising the steps of:
 discharging residual ink from an ink cartridge in which a porous member for
 ink absorption is accommodated;
 cleansing the porous member using cleansing fluid;
 discharging the cleansing fluid from the porous member; and
 impregnating the porous member with ink.
 Therefore, refilling of ink can be carried out with the porous member
 accommodated in the ink cartridge and without disassembly of the ink
 cartridge. The cleansing fluid can completely remove any residual ink.
 Thus, an ink cartridge can be recycled at a low cost, and the same quality
 can be provided as that provided by a brand new one, without any
 contamination.
 The present disclosure relates to the subject matter contained in Japanese
 patent application Nos. Hei. 10-364143 (filed on Dec. 22, 1998), and Hei.
 11-358714 (filed on Dec. 17, 1999), all of which are expressly
 incorporated herein by reference in their entireties.

DESCRIPTION OF THE PREFERRED EMBODIMENT
 FIGS. 1 and 2 are diagrams showing an ink cartridge, according to one
 embodiment of the present invention, for which a manufacturing method of
 this invention is applied. A container 1, having a substantially
 rectangular, parallelpiped shape, is formed by the injection of a polymer
 material, with the open side being slightly larger than the opposite side.
 The container 1 has walls 2 defining a plurality of ink chambers 3. In
 each of the ink chamber 3, a porous member 4, made of a flexible material
 that is appropriate for ink absorption is accommodated in a compressed
 state. Formed at the bottom end of each chamber 3, is an ink supply port 5
 which receives an ink supply needle or ink supply tube of a recording
 head. An opening 6 is sealingly closed by a lid 9 having ink introduction
 holes 7 and air communication holes 8.
 A projecting portion 10 is provided for each ink chamber 3 to compress the
 porous member 4 in the vicinity of the ink supply port 5. The upper end of
 the projection portion 10 is formed into a recessed portion 12 that
 defines a chamber 11 having a predetermined opening area. A through-hole
 13 extends from the chamber 11 to the ink supply port 5. A packing 16 is
 fitted on the outer end portion of the through-hole 13. The packing 16 is
 adapted to hermetically engage the ink supply needle or ink supply tube of
 the recording head. A gas impermeable film 17 is attached to cover the ink
 supply port 5. The film 17 is made, for example, of a low density
 polyethylene film having low moisture permeability, and can be broken upon
 the ink supply needle is inserted into the ink supply port 5. Reference
 numeral 18 in FIGS. 1 and 2 denotes a filter member that is provided to
 cover the recessed portion 12.
 As shown in FIG. 3, meandering grooves 19 are formed in the upper surface
 of the lid 9, each of which is communicated at its one end with a
 corresponding air communication hole 8. The other end of each meandering
 groove 19 is extended to the lower side of the lid 9 in FIG. 3. A film 20
 is attached to the lid 9 to cover a hatched area. The lower half of the
 film 20 in FIG. 3 can be peeled off by lifting a tongue piece 20a.
 The re-filling method will now be described.
 The surface of an ink cartridge collected from a user is cleaned, and the
 films 17 and 20 are peeled off from the ink supply ports 5 and the lid 9.
 Then, the ink cartridge is set on a work table 31 in which suction ports
 30 are formed as shown in FIG. 4 to engage the ink supply ports 5.
 As shown in FIG. 5, negative pressure is applied to the ink supply ports 5
 by an ink suction device that communicates with the suction ports 30, so
 that ink remaining in the porous members 4, etc. is removed by suction.
 Hollow needles 32, which communicate with a device for supplying a
 cleansing fluid that is, for example, refined water, a solvent, a
 constituent of ink, are abutted upon or inserted into the ink introduction
 holes 7 and the air communication holes 8 in the lid 9 to introduce the
 cleansing fluid of an amount required to impregnate the porous members 4,
 preferably 1 to 15 times of the amount, more preferably 3 times or greater
 of the amount. As a result, the cleansing fluid flowing from the top of
 the cartridge permeates the porous members 4, and then flows out of the
 ink supply ports 5 to the suction ports 30 while diluting and dispersing
 the residual ink.
 After the cleansing step ends, the cleansing fluid is discharged from the
 porous members 4. The cleansing fluid discharge step is preferably carried
 out such that negative pressure is applied to the ink supply ports 5 so
 that the cleansing fluid is forcibly extracted by suction.
 More preferably, each of the cleansing step and the cleansing fluid
 discharge step is divided into plural sub-steps, so that the cleansing
 substeps and the cleansing fluid discharge sub-steps are carried out
 alternately. In other words, a required amount of the cleansing fluid to
 be introduced during the cleansing step is divided, so that the cleansing
 step is carried out plural times each followed by a cleansing fluid
 discharge step using suction. Further, it is also preferable and effective
 to vary the amount of cleansing fluid and the inflow rate of the cleansing
 fluid depending on the number of times the cleansing has been carried out,
 i.e., the degree of cleansing achieved. Moreover, an amount or flow rate
 of the cleansing fluid supplied during one cleansing sub-step may be
 different from an amount or flow rate supplied during another cleansing
 sub-step.
 Thereafter, the cleansing fluid retained by capillary attraction in the
 porous members 4 is removed by natural drying, ventilation drying or
 decompression drying. That is, the ink cartridge is maintained at room
 temperature, dry air is introduced via the ink introduction holes 7 and
 the air communication holes 8 of the lid 9, or via the ink supply ports 5,
 the ink cartridge is placed in a decompression chamber, etc.
 More preferably, the cleansing fluid retained by capillary attraction is
 volatilized by heating the ink cartridge for a predetermined period of
 time, e.g., for one day, at a temperature, e.g., 60.degree. C., at which
 no deterioration of the porous members 4 occurs. This makes it possible to
 easily and surely remove the cleansing fluid from the porous members 4
 without any great change to the manufacturing line. Thus, productivity can
 be improved.
 Still more preferably, after the cleansing fluid has been discharged from
 the porous members 4, the ink cartridge is heated for approximately 24
 hours at a temperature of approximately 60.degree. C. Then, the ink
 cartridge is placed in a vacuum chamber for vacuum drying until the
 cleansing fluid is reduced to approximately 0.4 g per 80 g of the porous
 member 4.
 After the cleansing fluid has been discharged, the ink supply ports 5 of
 the ink cartridge are sealed by attaching to them gas-impermeable films
 17, respectively. It is also preferable that the packing 16 be replaced
 with new one at this time. The replacement of the packing 16 that has been
 thermally deteriorated during the cleansing step or the cleaning fluid
 discharge step with new one improves the reliability or quality of the
 recycled product.
 As shown in FIG. 6, an introduction tube 34 that communicates with an ink
 supply unit 33 is inserted through the ink introduction hole 7 into the
 porous member 4. A discharge tube 35, which communicates with a vacuum
 pump, is connected to the air communication hole 8. While removing air
 from the upper space of the cartridge, a predetermined amount of degassed
 ink is introduced into the porous member 4 from a metering pipe 42 to
 which ink from a tank 41 has been preliminarily supplied via a degassing
 unit 40.
 In a case where an ink cartridge is recycled to an ink cartridge having the
 same specifications as the former ink cartridge, it is preferable that the
 density of effective ink constituent elements, such as pigments, dyes,
 surface-active agents or moisture solvents, be slightly reduced. That is,
 since the porous member of the ink cartridge has been so impregnated with
 the effective constituent elements of the initially filled ink that those
 elements can no further be dissolved, the effective constituent elements
 of the ink used for re-filling will not be absorbed by the porous member
 4, and the density of the ink will not be reduced.
 Subsequently to filling the ink of a predetermined amount,the
 gas-impermeable film 20 is attached to the surface of the lid 9 to seal
 the ink introduction holes 7, the air communication holes 8, and the
 grooves 19.
 Then, as shown in FIG. 7, the tongue piece 20a of the film 20 is folded
 down and the container 1 is inserted into a bag 35 formed of an
 air-impermeable film.
 An opening 35a is thereafter closed by heat sealing in a reduced-pressure
 environment. As shown in FIG. 8, the bag 35 is then stored in a case 36 on
 which the trademark of the recycling company is displayed. In this
 fashion, the production of the product is completed.
 If the suction ports are formed as hollow needles 50 as shown in FIG. 9,
 then, as is shown in FIG. 10, the hollow needles 50 can be inserted into
 the ink supply ports 5 in the same manner as when the ink cartridge is
 mounted on a recording head, and the cleansing fluid can be drawn out.
 In the above description, an ink cartridge in which all ink is impregnated
 in the porous members 4 has been explained. The same effects can be
 obtained by applying the recycling process of the present invention to an
 ink cartridge shown in FIG. 11, in which a form chamber 3 is divided by a
 wall 1b having a communication hole 1a to have an ink chamber 37.
 In the above description, the film 17 is attached to the ink supply port 5
 to seal the ink supply port 5. The present invention is not restricted
 thereto or thereby. For example, the packing member 16 per se may have the
 sealing function for the ink supply port 5, or an integrally formed member
 having both the sealing function and the packing function may be used. In
 this case, it is preferable to detach the packing member 16 or the
 integrally formed member from the ink supply port 5 prior to the negative
 pressure applying step, and to attach the packing member 16 or the
 integrally formed member to the ink supply port 5 (or to attach a new
 packing member 16 or a new integrally formed member to the ink supply port
 5) prior to the ink refilling step.