JPH07239624A - Heat fixing roller - Google Patents

Abstract

PURPOSE:To effectively prevent generation of an offset without generating thermal deterioration of fluororesin and gradation of release property by instantaneously applying heat to the surface of the fluororesin after coating the surface of an arbor with the fluororesin, thereby rapidly melting and forming only the surface of the fluororesin. CONSTITUTION:A fixing device 1 has a heat fixing roller 2, an elastic rubber roller 3 pressed thereto and a separating pawl 4 of which the front end comes into contact with the surface of the heat fixing roller 2. The heat fixing roller 2 is formed by providing the surface of a cylindrical arbor 6 with a well releasable fluororesin 7 and internally arranging a heater 8. Heat is instantaneously applied to the surface of the fluororesin 7 after the surface of the arbor 6 of the heat fixing roller 2 is coated with the fluororesin 7, thereby, only the surface of the fluororesin 7 is rapidly melted and the roller is formed. Then, the fluororesin 7 is not reheated for a long period of time at a high temp. and, therefore, the thermal deterioration of the fluororesin 7 does not arise and the release property of the fluororesin 7 is not deteriorated. The generation of the offset is thus effectively prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing roller used in electrophotographic copying machines and the like.

[0002]

2. Description of the Related Art As a conventional heat-fixing roller of this type, a cored bar having a surface coated with a releasable fluorine resin is used. There is a problem that a part of the toner adheres to the heat fixing roller to cause offset. Therefore, in order to solve such a problem, the ones disclosed in (1) JP-A-61-141472 and (2) JP-A-63-264782 have been proposed, and (1) The heat fixing roller of
1 hour at 300 °, (2) heat fixing roller at 320 ° 15
Reheating for ~ 40 minutes.

[0003]

However, since such a heat-fixing roller is reheated at a high temperature for a long time as described above, the fluororesin causes thermal deterioration and the releasability of the fluororesin is deteriorated. Therefore, the occurrence of offset cannot be effectively prevented, the surface hardness is easily scratched, the durability is reduced, and the adhesion strength of the fluororesin to the core metal is reduced, resulting in the exfoliation of the fluororesin. However, there are various problems that the cost is increased due to the reheating process for a longer time.

Therefore, an object of the present invention is to eliminate the problems of the conventional heat fixing roller as described above, to prevent re-heating at a high temperature for a long time, and to prevent the fluororesin from being thermally deteriorated. It is possible to effectively prevent the occurrence of offset without lowering the releasability of the resin, the surface hardness does not lower, scratches are less likely to occur, and the durability does not lower. It is an object of the present invention to provide a heat fixing roller in which the adhesive strength of the fluororesin with respect to the above does not decrease, the fluororesin does not peel off, and the cost does not increase because it is not reheated for a long time.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a heat fixing roller in which the surface of a cored bar is provided with a releasable fluororesin. In the above, the fluororesin is formed by coating the surface of the core metal and then instantaneously applying heat to the surface to melt only the surface of the fluororesin in a short time. The invention of claim 2 is the same as the invention of claim 1,
Before melting the surface of the fluororesin, the surface is polished. According to a third aspect of the present invention, in the second aspect of the present invention, the surface of the fluororesin is ground, but before the surface is melted, the static elimination treatment is performed so as to bring the potential of the surface close to zero. According to the invention of claim 4, in the invention of claim 1, when heat is instantaneously applied to the surface of the fluororesin to melt only the surface of the fluororesin, the heat fixing roller and the heat source are surrounded by a mirror surface on the inner surface. It is surrounded by a member and then heated. According to a fifth aspect of the present invention, in the first aspect of the invention, a heating source that repeats blinking in a short cycle is used, and heat is instantaneously applied to the surface of the fluororesin to melt it.

[0006]

The heat fixing roller 2 as described above is used in the same manner as a conventional heat fixing roller to fix a toner image on a transfer sheet. In this heat fixing roller 2, the surface of the cored bar is used. Fluorine resin is coated, and after this fluorocarbon resin is baked, it is polished and washed to remove the polishing powder generated during polishing, and the surface of the heat fixing roller is neutralized to eliminate the potential of a large negative charge. When cleaning and static elimination are completed in this way, the heating and fixing roller is attached with a mirror surface material on the inner surface,
Multiple xenon flash lamps have been established.The re-baking members are capped so that there are no gaps, the xenon flash lamps flash and emit light, and they are rotated in any direction by any means. Heat is applied to melt the surface of the fluororesin in a short time.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the embodiment of the present invention shown in FIGS.
A fixing device 1 includes a heat fixing roller 2, an elastic rubber roller 3 pressed by the heat fixing roller 2, and a separating claw 4 whose tip is in contact with the surface of the heat fixing roller 2, and the heat fixing device 1 is provided. The roller 2 has a cylindrical core metal 6 on the surface of which a releasable fluorine resin 7 is provided, and a heater 8 is arranged inside. A transfer paper having the toner image 9 transferred to the surface of the fixing device 1 by a transfer device (not shown).
11 is fed to the nip portion between the rollers 2 and 3 by the guide plate 12, heated and pressed to fix the toner image 9,
The paper is ejected to the outside of the apparatus by the paper ejection roller pair 14 via the guide plate 13.

In the heat fixing roller 2 as described above, the core metal 6 has a wall pressure of 0.3 to 6 mm, and the fluororesin 7
Has a film thickness of 5 to 40 μm.
Using fluorinated ethylene resin, perfluoroalkoxy resin, or perfluoroethylene propylene resin,
This is coated. Then, after baking such a fluororesin 7, it is polished and washed with ethyl alcohol to remove the polishing powder generated at the time of polishing, and the surface of the heat fixing roller 2 is neutralized, so that the negatively charged potential is large. Approaches 0. This charge removal can be performed more effectively by directly or indirectly installing the core metal 6 when cleaning the heat fixing roller 2.

When the cleaning and static elimination are completed in this way, the heating and fixing roller 2 is erected on the pedestal 16, as shown in FIG. The rectangular tube-shaped re-baking member 17 in which the xenon flash lamp 19 is established is capped so that there is no gap between it and the pedestal 16, and the xenon flash lamp 19 flashes to emit light, and the pedestal 16 is arbitrarily Rotate in any direction by means. As a result, heat is instantaneously applied to the surface of the fluororesin 7, and only the surface of the fluororesin 7 is melted in a short time.
At this time, one emission time of the xenon flash lamp 19 is 5 to 500 msec.
The total emission time of is approximately 10 seconds to 5 minutes. However, this emission time differs depending on the number of xenon flash lamps 19, the wavelength of the emission spectrum, the distance between the xenon flash lamp 19 and the heating and fixing roller 2, etc., and in short, the surface of the fluororesin 7 must be melted with the minimum necessary amount of heat. It only has to be a time to work.

FIG. 6 shows the heat fixing roller 2 as described above.
Of the re-firing process, the pedestal 16 on which the heat fixing roller 2 is erected is placed on the belt conveyor 21 moving in the direction of the arrow, and the heat fixing roller 2 is rotated in step I. Meanwhile, the injection nozzle 22 is used to wash with ethyl alcohol, remove the charge, and naturally dry in Step II, and in Step III, only the surface of the fluororesin 7 is melted in a short time by the re-baking member 17 as described above.
Then, in step IV, the re-baking member 17 is removed, and the heat fixing roller 2 is naturally cooled or forcedly cooled to complete the re-baking process.

FIGS. 7 and 8 show an example of a conventional re-baking process. In this example, a pedestal 26 having 40 to 60 heat fixing rollers 2 erected thereon is attached with a heater 27. It was set in the heating furnace 28 in which the temperature inside the furnace had become high and was refired. However, in such a case, the heating and fixing roller 2 is, as shown in FIG.
When the temperature of the heat fixing roller 2 located at the location B becomes higher than a predetermined temperature or the set temperature is lowered, the location A is different from the location A in the location A.
The heating and fixing roller 2 located at the position B becomes lower than a predetermined temperature, and the baking time at the predetermined temperature or higher differs depending on the position of the heating and fixing roller 2. Then, the fluororesin 7 is deteriorated by heat, and conversely, if the baking time is shortened, the heat fixing roller 2 located at the location A is too short in time to obtain a predetermined effect. On the other hand, such a thing does not occur in the above-mentioned re-baking step in the present invention.

[0012]

The present invention is as described above, and the invention of claim 1 is a heat fixing roller in which a surface of a core metal is provided with a releasable fluorine resin, wherein the fluorine resin is the core metal. After coating the surface of the fluorocarbon resin, the surface is instantly heated, and only the surface of the fluorocarbon resin is melted and formed in a short time. It is possible to effectively prevent the occurrence of offset without deteriorating the mold release property of the fluororesin, the surface hardness does not decrease, scratches are less likely to occur, and the durability is improved. The effect that the cost does not decrease, the adhesive strength of the fluororesin to the core does not decrease, the fluororesin does not peel off, and it does not need to be reheated for a long time. There is. According to the invention of claim 2, in the invention of claim 1, the surface of the fluororesin is polished before being melted, so that the surface is smooth without protrusions and has good releasability. Further, it is possible to effectively prevent the occurrence of offset, and it is possible to eliminate polishing scratches due to melting after polishing. The invention of claim 3 is the same as claim 2
In the invention, after the surface of the fluororesin has been polished and before melting, the static elimination treatment is performed so as to bring the potential of the surface close to zero, so that dust, dust, fine powder, etc. do not adhere, There is an effect that the moldability is good and the occurrence of offset can be effectively prevented. According to the invention of claim 4, in the invention of claim 1, when heat is instantaneously applied to the surface of the fluororesin to melt only the surface of the fluororesin, the heat fixing roller and the heat source are surrounded by a mirror surface on the inner surface. Since it is surrounded by members and heated, there is an effect that heat loss is small and efficient heating is possible, and cost can be reduced. According to the invention of claim 5, in the invention of claim 1, since the surface of the fluororesin is instantaneously heated and melted by a heating source that repeats blinking in a short cycle, deterioration of the fluororesin does not occur. Therefore, there is an effect that it can be uniformly heated and the occurrence of offset can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of the present invention.

FIG. 2 is an enlarged front view of the main part of the above.

FIG. 3 is a perspective view showing an initial state of the re-baking step in the above.

FIG. 4 is a perspective view showing the next state of the above.

5 is an enlarged cross-sectional view taken along line 5-5 of FIG.

FIG. 6 is an overall explanatory diagram of an example of the re-baking step.

FIG. 7 is a perspective view showing an initial state of a conventional re-firing process.

FIG. 8 is a drawing showing a relationship between heating time and temperature rise in the above.

[Explanation of symbols]

 1 Fixing device 2 Heat fixing roller 3 Elastic rubber roller 6 Core metal 7 Fluorocarbon resin 8 Heater 9 Toner image 11 Transfer paper 16 Receiving stand 17 Re-burning member 18 Mirror surface material 19 Xenon flash lamp

Claims (5)

[Claims] 1. A heating and fixing roller having a core metal surface provided with a releasable fluororesin, the fluororesin covering the surface of the core metal, and then momentarily applying heat to the surface, A heat fixing roller characterized in that only the surface of fluororesin is melted and formed in a short time. 2. The heat fixing roller according to claim 1, wherein the surface of the fluororesin is polished before the surface is melted. 3. The heat-fixing roller according to claim 2, wherein after the surface of the fluororesin is polished and before it is melted, a static elimination treatment is performed so as to bring the potential of the surface close to zero. 4. Heat is momentarily applied to the surface of the fluororesin,
The heat-fixing roller according to claim 1, wherein, when only the surface of the fluororesin is melted, the heat-fixing roller and the heat source are surrounded by an enveloping member having a mirror surface on the inner surface and then heated. 5. A heating source that repeats blinking in a short cycle,
The heating and fixing roller according to claim 1, wherein heat is instantaneously applied to the surface of the fluororesin to melt it.