JPS59228275A - Cleaning brush roll used for electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To obtain the titled brush roll having always constant cleaning ability independent of the environment in which it is used, and the qualities of materials in contact with the brush, such a photosensitive body, by using flocked electret fibers. CONSTITUTION:Soft hair 4 of electret fibers of fibrous material given on the surface, positive and negative electrostatically charged zones by the electret production treatment are flocked on basic cloth 3 wound around the core pipe 2 of a brush roll 1. When this brush roll 1 is used, a positively and negatively charged toners are attracted to the negatively and positively charged zones, respectively, resulting in weakening mechanical wiping force by this attraction force, and lowering the interferences of the rotation speed, etc. of the roll 1 with a photosensitive body. Accordingly, damage of said body due to mechanical impaction can be alleviated, and remarkable extension of the life of a photosensitive material can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cleaning brush roll for wiping off untransferred residual toner on a photoreceptor of an electronic copying machine, and more particularly to its fiber material.

Conventional electronic copying machines require a cleaning device to wipe away untransferred residual toner remaining on the photoreceptor after transfer, and generally a cleaning brush roll with soft bristles is used. There is. This brush cleaning not only mechanically wipes off toner, but also electrostatically attracts toner to the brush roll by frictional electrification caused by the photoreceptor of fluff. but,
It is sufficient that the untransferred residual toner entering the cleaner section is charged to only one polarity, but toner of the opposite polarity is always included.

Therefore, with a general brush roll in which soft bristles made of a single material are implanted, the brush roll is charged to a single polarity due to friction, so the brush roll has a single polarity.
There was a problem in that the printing efficiency was poor and it had an adverse effect on the next copying.

For the purpose of solving such problems, for example,
Publication No. 151976 discloses that, especially in the case of cleaning in a two-color electronic copying machine, a base fabric is wound in two spirals on the circumferential surface of a core and adhered, and hair-like bodies of Teflon and rayon are individually attached to this. A brush roll in which a large number of brush rolls are installed in the radial direction and has a Teflon hair-filled area that is tribo-electrified to a negative polarity and a rayon-made hair-filled area that is tribo-charged to a positive polarity; A brush roll in which a mixture of seed hairs is planted has been proposed. In addition, Japanese Utility Model Publication No. 56-30844 describes two or more types of fibers with conflicting triboelectric polarities, such as positively chargeable fibers such as wool, nylon, cotton, glass fiber, and animal fiber, acrylic, polyester, and tetrafluorocarbon fibers. It has been disclosed that brush bristles are formed using negatively charged fibers such as ethylene chloride, and furthermore, Japanese Utility Model Application No. 55-48171 discloses that
It has been disclosed that a brush roll is constructed from bristles that are positively triboelectrically charged and bristles that are negatively triboelectrically charged, and that two brushrolls each made of these two types of materials are used.

However, when the entire brush roll is made of the above-mentioned materials, the amount of charge of such materials changes depending on the usage environment (temperature, humidity, etc.) and the degree of deterioration, and the amount of charge on the materials that come into contact with the brush roll (photoreceptor, etc.) There is a close relationship with the materials of the flicker bar, and if these materials are changed, there is a problem that the blending ratio of brush fibers must be changed to optimize the problem.

OBJECTS OF THE INVENTION Accordingly, an object of the present invention is to provide a cleaning brush roll for an electronic copying machine that always has a constant and excellent cleaning ability, regardless of the usage environment or the brush contact material such as the photoreceptor. be.

Structure of the Invention The cleaning brush roll according to the present invention is characterized by being flocked with electret fibers.

Here, the electret fiber refers to a fibrous material that has both positively and negatively charged regions on its surface due to electret treatment.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the accompanying drawings showing examples.

FIG. 1 shows a cross-sectional view of a cleaning brush roll according to the present invention, in which the soft bristles 4 of the electret fibers are planted on a base fabric 3 wound around the circumferential surface of a core tube 2 of a brush roll 1. There is.

The electret fiber fluff 4 may be in any form such as a single yarn, a twisted yarn, or a twisted yarn.

Next, an example of a method for manufacturing a brush roll according to the present invention will be described with reference to the drawings.

Brush roll manufacturing method: In Fig. 2, 5 is a film suitable for electret such as PFA (perfluoroalkoxy) or FEp (fluoroethylene propylene) with a thickness of 10 to 30 μm.
An electret treatment is performed by corona irradiation, ion beam irradiation, etc. so that the l-face is charged to 2 to 3 KV and the other face is charged to -2 to -3 KV. This is 20
The fibers are slit using a slitting device equipped with multiple cutters to a width of about 50 ltm. Approximately 100 electret fibers 6 thus produced are bundled into a yarn, which is used to create a brush roll according to the steps shown in FIG. 3 (FIGS. 4 to 9). Note that when the electret fiber reaches a high temperature state, the electric charge generates thermal runaway, so it is necessary to maintain the temperature of the fiber at about 70° C. or lower during the entire process. Each step will be explained below.

Pile weaving process: Both ends of the pile 7 made of the described electret fibers are planted on the base fabrics 8, 8' (see FIG. 4). It is preferable that the distance between the base fabrics 8, 8' is set to a maximum of 38 mm.

Pile cutting process: A cutter 9 is inserted into the material obtained in the pile weaving process at a position in the middle of each base fabric 8, 8' to cut the pile 7 (see FIG. 4).

Belt cutting process: The pile planting base fabric 8 obtained in the above process is cut into a width of 30 to 50 r.
Cut into a belt shape to obtain a pile belt (not shown).

Unraveling process: The obtained pile belt 10 is passed over the unraveling roller 11 on which a steel heel (for example, piano wire, etc.) with a length of 15 cm and a diameter of about 1 mm is implanted on the roller surface. The pile belt 10 is conveyed in the direction opposite to the direction of rotation of the pile belt 10 while being kept at a constant interval by the backup blade 12.
The pile 7 is unraveled by the steel wire of the unraveling roller 11 (see FIG. 5). In addition, the conveyance speed of the pile belt 10 is 50 to 1
00 questions/5CjC, the rotation speed of the unraveling roller 11 is approximately 3
00τP+7L is appropriate.

Packing process: This process is a tweezing prevention process, and is carried out by inserting and conveying the nozzle belt 10 between the coating roll 14 and the opposing roll 15, which are rotating while a certain amount of latex 13 is being applied. Latex is applied to the back side of the cylinder belt 10 (see FIG. 6).

Winding process: After fixing one end of the pile belt 10 to one end of the paper tube 16 by an appropriate means, the pile belt 10 is wound in a convoluted shape on the circumferential surface of the paper tube 16 while rotating it. (7th
(see figure).

Raising step: While rotating the brush roll 1 obtained in the above step at a constant speed, a water vapor jet is sprayed from the nozzle 17 onto the planted nozzles to raise the brush (see FIG. 8). The rotation speed of brush row 1 is approximately 2000-3000 rp
m, and the water vapor jet flow is approximately 1.5 ky/cA.

Shearing process: The fibers of the brush roll 1 are cut to a constant length by a rotating rotary cutter 18 and a fixed blade 19 in sliding contact with the cutter 18 (see FIG. 9).

The brush roll according to the present invention is obtained through the above steps.

Next, an embodiment of a brush cleaning device using a brush roll according to the present invention will be described with reference to the drawings.

In FIG. 10, the residual toner (toner remaining without being transferred to the paper) on the photoconductor 20 first enters the cleaner section, where it is exposed to the wiping action of the brush roll 1 rotating at about 120 rpm. It separates from the body 20 and either disperses into the air or adheres to the fibers 4 of the brush roll 1.

The toner attached to the fiber 4 is removed from the flicker bar 21.
Due to the collision between the fiber 4 and the fiber 4, it is separated from the scifi nano (-4) and dispersed in the air. It also has the role of sucking in all the air from the air inlet orifices 23 and 24 formed in the gaps between them and discharging it to the dust collecting section.The principle of this air pumping action will be explained with reference to Figs. 11 and 12. do.

In FIG. 11, as the brush roll 1 rotates, the air inside the brush fibers and the air around the outer periphery of the brush roll 1 are subjected to viscous resistance, producing an air flow in the direction of rotation of the brush roll 1. An obstruction-flicker bar 21 is provided in the flow path as shown, and the position of the flicker bar 21 is determined.

Interference amount between brush fiber and flicker bar (CEFI)
, the amount of interference between the brush fiber and the photoreceptor 20 (Bpl)
, and by appropriately selecting the shape of the cleaner housing 22, the pressure distribution inside the cleaner housing 22 can be adjusted to the first level.
It can be done as shown in Figure 2.

α is the flicker bar position, b is the exhaust position, C is the upper intake position, d is the contact position between the brush fiber and the photoreceptor, e is the lower intake position, P is the pressure distribution, and A is the atmospheric line.

As a result, as shown in FIG. 11, an air flow of ql+qt flows into the cleaner housing from the upper and lower openings of the cleaner housing 22 and flows in the direction shown by the arrow, toner particles inside the cleaner housing 22. 9. +9° airflow is exhausted through the exhaust port. To create a flow path like the one above, I) F I > B
The relationship PI+α needs to hold true.

The air containing the toner is discharged into the dust collecting channel 26 formed by the channel forming wall 25, where most of the toner particles in the air are electrostatically attracted to the dust collecting roll 271. Thereafter, it is separated from the dust collection roll 27 by a scraper 28 made of urethane rubber or the like, falls down, and is carried out of the cleaner unit by a screw 29. In addition, dust collection roll 2
The minute amount of toner that was not collected in step 7 is completely collected by the filter 30.

Functions and Effects of the Invention In the brush cleaning device shown in FIG. 10, the remaining toner on the photoconductor 20 that has not been transferred to the paper and the photoconductor 20 are first subjected to AC corona and light irradiation (not shown) to remove static electricity and perform cleaning. It enters the cleaner section in a state where it is easily damaged. However, it is impossible to completely remove the charge, and in reality, a mixture of positively and negatively charged toner exists.

Therefore, when a brush roll flocked with the electret fibers according to the present invention is used as the brush roll 1, the brush roll 1 rotates while rubbing the surface of the photoreceptor 20 in the cleaner section, and the fibers are mechanically wiped away. The cleaning action is a combination of the electrostatic action and the electrostatic action caused by the electret charge. That is, the force of attracting the positively charged toner to the negatively charged region of the fiber acts, and the force of attracting the negatively charged toner to the positively charged region of the fiber, thereby making it possible to weaken the mechanical wiping force by this amount. This leads to the fact that the number of rotations of the brush roll and the amount of interference (13 p I ) i between the brush roll and the photoreceptor can be reduced. Therefore, damage to the photoreceptor due to mechanical invasion can be completely reduced, and the life of the photoreceptor can be extended to a large extent. This action and effect is in sharp contrast to that of a brush roll, which uses electrostatic force through frictional charging.

As described above, since the cleaning brush roll according to the present invention is made of electret fiber's bristles, it is always available regardless of the usage environment (temperature, turbidity, etc.) or the brush contact material such as the photoreceptor. It has the excellent effect of not only exhibiting a certain level of excellent cleaning ability but also reducing damage to the photosensitive material and greatly extending its life.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the cleaning brush roll according to the present invention, FIG. 2 is an explanatory diagram showing an outline of electret fiber production, and FIG. 3 is an outline of the manufacturing process of the cleaning brush roll according to the present invention. Figures 4 to 9 are explanatory diagrams of the Iki process shown in Figure 3, Figure 4 is the pile cutting process, Figure 5 is the solution (p process, and Figure 6 is the packing process). , FIG. 7 is an explanatory diagram of a winding culm, FIG. 8 is an explanatory diagram of a raising process, and FIG. 9 is an explanatory diagram of a shirring process. FIG. 10 is an embodiment of a brush cleaning device using a cleaning brush roll according to the present invention. FIG. 11 is a schematic diagram illustrating the principle of the pumping action of the cleaner section. FIG. 12 is a pressure distribution diagram in the cleaner housing shown in FIG. 11. 1... Brush roll , 4... electret fiber fluff, 5... electret film, 6...
・Electret fiber, 7... pile, 3, g
, g'... Base fabric, 10... Pile belt, 20 Photoreceptor, 21... Flicker bar, 22... Cleaner housing, 27... Dust collection roll, 3o... Filtration type filter . Applicant Fuji Xerox Co., Ltd. Agent Patent Attorney Masaaki Yonehara Patent Attorney Tadashi Hamamoto Figure 1 Figure 2 @ Figure 3 Figure 10 Figure 30 Figure 11 Figure 12

Claims (1)

[Claims] A cleaning brush roll for electronic copying machines characterized by being flocked with electret fibers.