Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G11/00—Selection of substances for use as fixing agents
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G15/00—Apparatus for electrographic processes using a charge pattern
  • G03G15/20—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat
  • G03G15/2096—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using a solvent

Definitions

• the invention relates to a device and a method for fixing a toner image on a carrier material, in which a solvent vapor is applied to the toner image.
• the invention further relates to a device for printing and / or copying, in which such a device is used.
• a toner image is transferred to a carrier material, for example paper, which is initially not smudge-proof and abrasion-resistant to the carrier material. It is only through a fixing process that the toner image is firmly attached. connected to the carrier material, ie • fi xed is.
• a fixing process is usually used, in which the toner is subjected to heat and pressure. Here, the toner is melted using heated fixing rollers and pressed into the carrier material, so that the toner forms an adhesive bond with the carrier material. If no special paper preheating is carried out, this heat-pressure fixation is limited in the transport speed of the carrier material, for example to about 0.5 m / s to 0.7 m / s.
• fixing rollers that are soft and resilient must be used on both sides.
• Fixing rollers of this type have only a short service life and, because of their low cost-effectiveness, are only used in printers or copiers with a low printing volume. Furthermore, due to the resilience of the fixing rollers, the guidance of the carrier material is problematic, so that with such a fixing method 5 co M ⁇ ! H r ⁇ !
• the moisture content of the carrier material is not changed, so that a ripple caused by moisture changes, a plate or a curling is avoided.
• the cold fixation is largely independent of the thickness of the carrier material, so that, for example, papers with different paper thicknesses can be used without a major change in the fixing process. In this way, the type of paper can also be changed with little effort.
• An arrangement is known from ÜS-A-4, 311, 723 in which a paper web is passed through a fixing chamber with solvent vapor.
• the solvent vapor is in a container. Due to gravity and cooling tubes in the upper area of the container, the concentration of the solvent vapor increases towards the bottom of the container, so that an area with a high solvent concentration is created near the bottom of the container.
• the carrier material which enters the still unfixed toner images in the upper region of the container, is deflected downwards at a first deflection device and guided in the region of the high solvent concentration in the vicinity of the container base. There, the carrier material with partially fixed toner images is redirected again at a second deflection device and finally led out of the container again at the top via a third deflection device.
• the guide material necessarily touches the deflection devices, as a result of which the toner thereon can smear or detach, or pressure points are left behind. With this arrangement it is therefore not possible to fix carrier material to which double-sided toner images are applied.
• the arrangement shows a relatively slow start / stop behavior, because to stop the fixation, the deflection device from the area of the high solvent concentration upwards into an area with a low solvent concentration, in which a fixation no longer takes place, must be driven, for which a predetermined time is required.
• HFCKW123 and HFCKW141b since they have a much lower ozone potential. From now on, these partially halogenated hydrocarbons HCFCs took over the function of the flame retardant in mixtures of air and flammable solvents, such as acetone, propanols, etc.
• solvents such as acetone, propanols, etc.
• the use of pure HCFC141b without adding a solvent, such as e.g. Acetone proven to be advantageous since HCFC141b has a sufficient fixing action for these toners and is easy to recover as a single-phase material, since there are no mixing or demixing problems.
• toner is transferred from an intermediate carrier, e.g. a photoconductor drum, is transferred to a recording medium at a transfer printing station.
• a solvent vapor is applied to the toner on the photoconductor drum so that it becomes sticky.
• the record carrier e.g. Paper exposed to solvent vapor.
• the sticky toner adheres to the paper, which is also provided with solvent, as a result of which the transfer printing process and the fixing of the toner take place in a single process.
• a fixing device is also known from DE-A-2 613 066, in which a hot gas, in particular air, is applied to the toner material of the toner image on the recording medium.
• the temperature of this gas is ⁇ such that the toner melts and penetrates into the recording medium, for example paper.
• FIG. 1 shows a known fixing device with largely static solvent vapor
• FIG. 2 shows the build-up of an inert air layer between the paper web and the solvent vapor
• FIG. 3 the effect of solvent depletion
• FIG. 4 shows the principle according to the invention of the flow of flow toward the carrier material with a directed current
• FIG. 5 shows schematically the structure of a fixing device according to the invention
• Figure 6 shows a preferred embodiment of the
• FIG. 7 shows an exemplary embodiment in which the countercurrent principle is implemented
• FIG. 9 shows a simplified variant according to FIG. 8
• FIG. 10 shows an example with evaporator chambers which are arranged outside the fixing chamber
• FIG. 11 shows an exemplary embodiment in which a directional current is applied to the carrier material only from one side
• FIG. 12 shows the example according to FIG. 11, but with the countercurrent principle implemented
• FIG. 13 two fixing chambers connected in series
• FIG. 14 the example according to FIG. 13, the direct current principle being implemented in one chamber and the counter current principle being implemented in the other chamber,
• FIG. 15 two circuits with solvent vapor connected in series in a single chamber
• FIG. 16 shows an embodiment in which the carrier material is guided vertically through the fixing chamber
• FIG. 17 shows an exemplary embodiment in which the carrier material is guided through the fixing chamber at an angle of 45 °
• Figure 18 shows the embodiment of Figure 6, wherein the control flaps are pivoted into the deflecting position
• Figure 19 shows an embodiment with others
• Figure 1 shows the structure of a conventional fixing device similar to that according to the already mentioned US-A-
• a solvent vapor 12 is generated in a container 10. Cooling tubes 16 are arranged within the container 10 and cool the solvent vapor. Accordingly, the solvent concentration in the upper region 18 is lower than in a central region 20 and there, in turn, lower than in the bottom region 14. The highest solvent concentration is therefore found in this bottom region 14.
• the carrier material 22, generally a paper web with yet-unfixed toner images is discharged horizontally into the container 10 and is deflected at a first • deflection device 24 vertically downward and area into the area of high concentration of solvent in the bottom 14th The toner images are partially fixed in this way of the paper web 22. The paper web 22 is deflected again at a second deflection device 26 and is finally guided out of the container 10 again via a third deflection device 28.
• the carrier material 22 generally a paper web, passes through the fixing chamber 40 straight and horizontally, passing through a first narrow entry gap 42 and a narrow exit gap 44 opposite it.
• the entry gap 42 is designed such that no contact occurs between it and the carrier material 22 even when the web of material flutters or sags so as not to blur the toner image on both sides of the carrier material 22. If the "simplex printing" operating mode is used with only one-sided toner images on the carrier material 22, contact can take place on the side of the carrier material 22 opposite the toner images and corresponding guide elements can be arranged.
• FIG. 6 shows a preferred exemplary embodiment of the invention, in which toner images are fixed on both sides of the carrier material 22.
• the fixing device is CQ -P rH 1 rH CO -ti
• the carrier material 26 carries toner images only on one side, for example the upper side
• the components for fixing toner images on the lower side can be dispensed with, i.e. on the components arranged below the carrier material in FIG. 6, such as the evaporator, the crossflow fan, etc.
• the arrangement according to FIG. 6 can be designed in such a way that flammable solvents can be used which require technical safety measures in the context of explosion protection.
• An explosion flap 60 is thus arranged in the region of the outlet gap 44, which opens when the pressure is increased.
• the carrier material 22 is electrostatically discharged by means of a discharge device 62 using ionized air. All ignition sources are avoided within the fixing chamber 40. All parts of the device are grounded to avoid static electricity.
• a suction device 64, 66 is effective in each case, which sucks the solvent vapor escaping from the fixing chamber 40 in small quantities. Accordingly, no harmful or explosive solvent vapor concentrations can occur outside of the fixing chamber 40 even during prolonged operation.
• the arrangement according to FIG. 6 is also designed for a quick start / stop behavior.
• two control flaps 70, 72 are provided, which are shown in the release position in FIG. In this position, the current 34 can flow freely. Both control flaps 70, 72 can be pivoted into a deflection position in accordance with the pivoting directions P2, P4, so that solvent vapor no longer flows onto the carrier material 22.
• the control fold 70, 72 controlled in the deflection position.
• the suction device 66 is switched off.
• the . another suction device 64 then sucks fresh air into the fixing chamber 40 and the channel 58 and thus the area around the carrier material 22 is flushed with fresh air.
• the fixation process is suddenly interrupted by these measures.
• the fixing process is started again by pivoting the control flaps 70, 72 against the directions P2, P4.
• the suction device 66 is reactivated and the solvent flow for the evaporator 46 is started.
• the carrier material 22 is withdrawn in the direction of the printing unit, opposite to the direction Pl, before printing operation is resumed.
• the control flaps 70, 72 are only folded back into their release position when there is a flow in the channel 58 unfixed toner images again. This ensures that already fixed toner images do not go through a fixing process again.
• a sensor 74 is connected, which measures the solvent concentration. As will be explained in more detail below, this sensor 74 is used to regulate the solvent concentration to a constant value.
• FIG. 10 shows a further variant, in which the evaporator 46 is arranged outside the fixing chamber 40.
• the opening 52 is slit-shaped and is located in the vicinity of the cross-flow fan 56 on its suction side.
• opening 54 may have other embodiments.
• the point of introduction for the live steam into the circuit can be located anywhere in the circuit.
• Figure 11 shows an embodiment for simplex printing.
• the fixing process with the directed current 34 is effective only on one side of the carrier material 22.
• the direct current principle is used, in which the current 34 runs in the direction P1 of the transport of the carrier material 22.
• FIG. 12 shows the example according to FIG. 11 with the counterflow principle, in which the flow 34 runs counter to the transport direction P1.
• FIG. 13 shows an example in which two circuits with streams 34a and 34b are generated in succession. Both currents 34a, 34b act on the same side of the carrier material 22. The currents 34a and 34b are generated in two fixing chambers 40a, 40b connected in series. The synchronism principle is used in both chambers 40a, 40b.
• FIG. 14 shows an example similar to FIG. 13.
• the direct current principle is used in chamber 40a and the countercurrent principle is used in chamber 40b.
• FIG. 15 shows a further example similar to that according to FIG. 14, but with the currents 34a and 34b being generated in a single fixing chamber 40. The combined
• SH SH -P 0 ⁇ ⁇ X 4-1 ⁇ SH .ü 4-1 SH> • ti ⁇ d ⁇ • ti 4-1 ⁇ x:: 0 X: 0 d 3 • ti ⁇
• Reuse of the solvent can further reduce the overall solvent consumption.
• Toners with any polymer base such as, for example, based on polystyrene, polyester and others, can be used.
• a suitable solvent generally exists for each of these polymers.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Fixing For Electrophotography (AREA)
• Wet Developing In Electrophotography (AREA)
• Control Or Security For Electrophotography (AREA)
• Developing Agents For Electrophotography (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=7650956

Family Applications (1)

Country Status (5)

Families Citing this family (5)

Family Cites Families (15)

• 2000
  • 2000-08-01 DE DE10037464A patent/DE10037464A1/de not_active Withdrawn
• 2001
  • 2001-07-31 US US10/343,426 patent/US6915101B2/en not_active Expired - Fee Related
  • 2001-07-31 AT AT01971831T patent/ATE303615T1/de not_active IP Right Cessation
  • 2001-07-31 WO PCT/EP2001/008863 patent/WO2002010862A1/fr active IP Right Grant
  • 2001-07-31 EP EP01971831A patent/EP1307787B1/fr not_active Expired - Lifetime
  • 2001-07-31 DE DE50107307T patent/DE50107307D1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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