JPH01237583A - Device for cleaning peripheral surface of fixing rotary body - Google Patents

Abstract

PURPOSE:To prevent the generation of a running failure of a web, an excess application of a mold releasing agent to the peripheral surface of a rotating body, and an application failure by providing an elastic layer and a surface resin layer on a pressure roller. CONSTITUTION:As for a pressure roller 7, a silicone rubber sponge layer 72 being an elastic layer is formed on a mandrel 71, and on the outside of this sponge layer 72, a tube 73 of a fluororesin PFA is formed as a surface resin layer through an adhesive layer 74. Accordingly, since the tube 73 obstructs a fact that a mold releasing agent from a web 2 permeates into the inside of the pressure roller, it does not occur that the mold releasing agent permeates into the elastic layer 72 and even if the device is used for a long period of time, it does not occur that the diameter of the pressure roller 7 increases due to swelling of the mold releasing agent. In such a way, the web 2 is always pressed against the peripheral surface of a fixing roller 10 by moderate nip width, namely, pressing force, a cleaning function and a mold releasing agent applying function of the web 2 are displayed enough and the peripheral surface of the fixing roller 10 is maintained in a desirable state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fixing device such as an electrophotographic apparatus, and more particularly to a cleaning device for the peripheral surface of a rotating body such as a fixing roller.

[Prior Art] Conventionally, a fixing device in a known electrophotographic apparatus or the like has a pair of rotating bodies such as a fixing roller that are pressed against each other, and a sheet material or the like carrying an unfixed image between the pair of rotating bodies. Fixing is performed by passing the image through the image support material. However, when fixing is performed between rotating bodies (hereinafter referred to as fixing rollers) such as the fixing roller, offset toner may adhere to the circumferential surface of the fixing roller that is in contact with the unfixed image.

Therefore, a so-called web-type cleaning device has conventionally been known as a device that has both the cleaning function of adsorbing and removing the offset toner mentioned above and the function of applying a release agent to prevent offset to the circumferential surface of the fixing roller. There is. In this web-type device, a web-like strip made of non-woven fabric or the like is wound around a supply section, and is sequentially wound onto a winding section. is pressed against the circumferential surface of the fixing roller. By impregnating the web with a release agent in advance, it is possible to obtain an apparatus that satisfies both the cleaning function and the release agent application function. By the way, the pressing means that presses against the circumferential surface of the web fixing roller has a sufficient nip I! It is necessary to satisfy the condition that it must be pressed uniformly against the fixing roller with l1l (contact length in the circumferential direction with the fixing roller) and that the web should run smoothly toward the take-up side. silicone rubber.

A pressure roller whose surface layer is made of an elastic material such as silicone rubber sponge is used.

[Problems to be Solved by the Invention] However, the following problems have been pointed out regarding the pressure roller in which the elastic body is formed on the surface layer.

(2) The elastic body is in direct contact with the web and swells by absorbing the release agent (for example, high viscosity silicone oil) impregnated into the web, and the diameter of the pressure roller increases with long-term use. As a result, the nip width between the pressure roller and the fixing roller, that is, the contact area of the web changes, and the pressing force also changes, which prevents inconveniences such as excessive application of release agent to the circumferential surface of the fixing roller and poor running of the web. arise. On the other hand, as a measure to prevent such a situation, there is a method to swell the elastic body of the pressure roller with silicone oil in advance.Swelling with high viscosity oil requires a long time to process. In addition, it may be possible to use low-viscosity oil to moisten the product in a short period of time; however, low-viscosity oil evaporates quickly and is unsuitable for long-term use.

■・Also, when the elastic body swells, it absorbs the release agent from the web, so the amount of release agent applied to the fixing roller is insufficient, making it impossible to prevent offset. That will happen.

■Furthermore, in devices in which a heat generating member is disposed inside the fixing roller, the pressure roller that presses the web against the fixing roller also receives heat from the fixing roller and becomes heated; The elastic body of the pressure roller is made of silicone rubber, silicone rubber sponge, etc., and its interior usually contains unreactive low-molecular-weight silicone oil. There is also the problem that this silicone oil is heated internally and turns into steam, which evaporates to the outside and contaminates the optical system, the discharge wire of the charger, etc. in the periphery of the electrophotographic apparatus.

The present invention solves the above-mentioned problems of the web-type device that has conventionally been widely used as a device for cleaning the circumferential surface of the rotating body of a fixing device. It is an object of the present invention to provide a peripheral surface cleaning device for a fixing rotating body in which a releasing agent can be smoothly applied without changing the pressing force on the surface.

[Means for Solving the Problems] According to the present invention, the above object is to remove foreign matter adhering to the circumferential surface of a rotating body disposed in a fixing device, etc., and apply a mold release agent to the circumferential surface. A device comprising a belt-shaped object such as a web, a winding means for pulling out the web from a supply section and winding it in a predetermined direction, and a pressing roller that presses the web against the circumferential surface of the rotating body between the supply section and the winding section. The pressing roller has at least an elastic layer and a surface resin layer.

[Examples] Examples of the present invention will be described below based on the accompanying drawings. FIG. 1 shows cleaning as an embodiment of the present invention?
tM is a fixing roller 10 disposed inside the fixing device 1.
An example is shown below.

In the figure, 2 is a belt-like body (hereinafter referred to as web) such as a web for adsorbing and removing foreign matter such as offset toner attached to the circumferential surface of the fixing rope 1o and for applying a release agent. The web 2 is made of a material that has a cleaning function for adsorbing foreign matter and a function for sufficiently applying the impregnated release agent to the circumferential surface of the fixing roller 10. As the web 2, for example, a conventionally known nonwoven fabric or the like can be used.

Further, there is a high viscosity (for example, 10000c) on the web 2.
ST degree) silicone oil (for example, Shin-Etsu Chemical (
Co., Ltd. K F 96H101100 is impregnated.

This high-viscosity silicone oil has a function as a release agent that prevents excessive oil from flowing out from the web 2 and also improves cleaning of the circumferential surface of the fixing roller 10.
The web 2 is wound around a supply reel 5 serving as a supply section, and is successively wound onto a take-up reel 6 serving as a take-up section. A pressing roller 7 is provided between the supplying section and the winding section as means for pressing the web 2 against the fixing roller l opening.

As shown in the enlarged cross-sectional view in FIG.
A tube 73 (film thickness: 50 m in this embodiment) of fluororesin PFA is formed as a surface resin layer on the outside of the tube 73 with an adhesive layer 74 interposed therebetween.

Further, FIG. 3 shows a front view of the pressing roller rough with a part thereof cut away. At both ends of the pressure roller rough shown in the same figure, there are plates (to prevent low-molecular silicone oil that evaporates inside from evaporating around the outside even if the pressure roller 7 is used at an elevated temperature). A ring-shaped end seal plate 75 is provided. The above seal plate 75
are firmly fixed to the PFA tube 73 at both ends of the pressure roller 7 to ensure tight cutting properties inside the pressure roller rough.

According to the cleaning device of this embodiment having the above configuration, the tube 7 serves as the surface resin layer of the pressure roller rough.
3 prevents the release agent from penetrating into the inside of the pressure roller from the web 2, so that the release agent does not penetrate into the elastic layer 72, and even after long-term use, the diameter of the pressure roller rough is reduced by the release agent. It does not increase due to swelling. the result,
Since the web 2 is always pressed against the circumferential surface of the fixing roller 10 with an appropriate nip width, that is, with a pressing force, the cleaning function and release agent application function of the web 2 are fully exerted, and the circumferential surface of the fixing roller 10 is kept in a desirable state. Can be maintained. Also,
Even if the pressure roller 7 of this embodiment is used at an elevated temperature and the low-molecular silicone oil evaporates inside, the tube 73 on the circumferential surface of the pressure roller 7 prevents the silicone oil from evaporating to the outside. At both ends of the pressure roller rough, the seal plates 75 prevent evaporation to the outside, so that the surrounding area of the pressure roller 7 is not contaminated with evaporated silicone oil.

Note that the surface material for forming the surface resin layer of the pressure roller of the apparatus of the present invention is not limited to the fluororesin PFA tube shown in the above example.

For example, a heat-shrinkable tube of fluororesin PFA can be used as a surface material that enhances adhesion to the internal elastic layer of the pressure roller and facilitates placement at the end of the pressure roller. If this shrinkable tube is used, the intermediate adhesive layer described above is not required. In addition to the above PFA, FEP, EFF
It is possible to use a fluororesin such as E, PTFE, or a known resin material having elasticity and heat resistance.

Furthermore, as a means for forming a surface layer on the elastic layer, in addition to the resin tube, the above-mentioned materials can be applied as a powder or liquid onto the elastic layer and fired to form a coating layer as a surface layer. It is also possible to form a It is also possible to employ a fluororubber latex layer as the surface layer.

[Effects of the Invention] According to the cleaning device of the present invention configured as explained above, a surface resin layer is formed on the elastic layer of the pressure roller, and the mold release agent does not penetrate into the elastic layer. Therefore, the diameter of the pressing roller does not change due to the 11th adjustment.

As a result, even if the pressure roller is used for a long period of time, it can always press against the circumferential surface of the rotating body as a web with the desired nip width at the beginning of the equipment. Excessive coating and poor coating are prevented.

Also, when using the pressure roller under heating,
Placing plates are disposed at both ends of the pressure roller to seal the inside to prevent low-molecular oil from evaporating from inside the pressure roller, thereby preventing contamination of peripheral equipment.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a fixing roller device using an apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a pressure roller used in the device shown in FIG. 1, and FIG. FIG. 3 is a partially cutaway front view of the pressure roller shown in FIG. l...Fixing device lO...Rotating body (fixing roller) 2...
Band-shaped body (web) 5... Supply section (supply reel) 6... Winding section (take-up reel) 7... Press roller (72... Elastic layer. 73...Surface resin layer)

Claims (2)

[Claims] (1) A belt-shaped body such as a web that removes foreign matter adhering to the circumferential surface of a rotating body disposed in a fixing device, etc., and applies a release agent to the circumferential surface, and pulls out the web from a supply section in a predetermined direction. A device comprising: a winding means for winding the web; and a pressing roller that presses the web against the circumferential surface of the rotating body between the supply section and the winding section, the pressing roller having at least an elastic layer and a surface resin layer. A peripheral surface cleaning device for a fixing rotor, characterized in that: (2) The fixing device according to claim 1, wherein sealing plates fixed to the surface resin layer are disposed at both ends of the pressure roller in order to seal the inside of the pressure roller. Equipment for cleaning the peripheral surface of rotating bodies.