JP3458540B2 - Cleaning blade and mold for molding the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning blade for removing toner remaining on the outer peripheral surface of a photosensitive drum of an electrophotographic copying machine and a molding die for molding the cleaning blade.

[0002]

2. Description of the Related Art An electrophotographic copying machine is provided with a photosensitive drum having a photoconductor surface layer, the outer peripheral surface of the photosensitive drum is uniformly charged, and then the outer peripheral surface of the object is passed through an image to be copied. Is exposed to form an electrostatic latent image on the outer peripheral surface, toner is attached to the electrostatic latent image to form a toner image, and the toner image is transferred to a copy paper or the like to perform copying. is there. After the copying, as shown in FIG. 9, since the toner 2 remains on the outer peripheral surface of the photosensitive drum 1, it is necessary to remove the residual charged toner 2. This removal is performed by the cleaning blade 3. There is. The cleaning blade 3 is attached to the resin case 8 with a screw 7, and the elasticity of the blade member 5 is used to bring the tip end thereof into sliding contact with the outer peripheral surface of the photosensitive drum 1 to cause the toner 2
Is designed to be removed. As such a cleaning blade 3, as shown in FIG. 10, generally, a thick-walled plate-shaped soft urethane resin blade member 5 is provided at one end of a metal plate-shaped holder 4 having a substantially L-shaped cross section. What is fixedly formed is used. The blade member 5 is formed such that a sliding contact side surface 5a that is in sliding contact with the photosensitive drum 1 is formed into a smooth surface, and an edge portion 5c has a sharp corner. As a result, the sliding contact side surface 5a is attached to the photosensitive drum 1.
The outer peripheral surface is evenly brought into close contact with and slidably contacted, and the toner 2 is scraped off by the sharp edge portion 5c so that the toner 2 can be sufficiently removed. In the figure, 6
Is a mounting hole which is formed at both ends of the plate-shaped holder 4 and through which the screw 7 is inserted to mount the cleaning blade 3.

The cleaning blade 3 is, for example,
It is manufactured as follows. That is, first, in FIG.
As shown in FIG. 3, the mold is divided into an upper mold 8a and a lower mold 8b, and a molding space 7 for molding a blade member is formed in the center of the mold, and the plate-shaped holders 4 are formed on both sides of the molding space 7. Mold 8 having a gap 9 to be held
To prepare. The mold 8 has a molding space 7 for the upper mold 8a.
Is a portion corresponding to the sliding contact side surface 5a of the blade member 5, and the smoothness of the sliding contact side surface 5a is ensured by forming the entire back surface on the mirror surface portion 7a. There is. Then, a mold release agent is uniformly applied to the wall surface of the molding space 7, and two plate-shaped holders 4 are attached to one end of the plate-shaped holder 4 to form a predetermined space inside the molding space 7 for forming the blade of the lower mold 8b. The lower mold 8b is clamped by the upper mold 8a in a state where the upper mold 8a and the lower mold 8b are abutted against each other and positioned in the gap 9. Next,
By injecting a urethane resin molding member into the molding space 7 of the mold 8 that has been clamped, and curing and then removing the mold member, as shown in FIG. 12, the two plate-shaped holders 4 have wide blades. A molded product integrated by the member 10 is obtained. After that, the wide blade member 10 is cut along the chain line in FIG. 12 to be separated into two pieces, and two cleaning blades 3 are formed as shown in FIG. Cleaning blade 3 thus obtained
Means that the sliding contact side surface 5a of the blade member 5 is the molding space 7
The mirror surface portion 7a is formed to be a smooth surface, and the cut surface 5b is also a smooth surface. The corner of the edge portion 5c formed by the cut surface 5b and the sliding contact portion 5a is in a raised state. It is formed.

[0004]

However, in the mold 8 described above, since the entire inner surface of the molding space 7 is formed as the mirror surface portion 7a, the mold release agent applied to the wall surface of the molding space 7 is If the film thickness is too thin, the surface of the molded product adheres to the mirror surface portion 7a and the force required for peeling increases, and when the molded product is released from the mold, the urethane resin may deform or break. However, there arises a problem that defective products occur. On the other hand, when the film thickness of the release agent is too thick, the molded product can be released from the mold without any problem, but a large amount of the applied release agent remains on the mirror surface portion 7a in the form of water drops and the urethane resin. As a result, a large number of minute recesses are formed on the surface of the molded product, which is a disadvantage. When the minute concave portions appear on the edge portion 5c, the toner 2 cannot be scraped off sufficiently, resulting in a defective product having insufficient cleaning performance. Therefore, in the above-mentioned mold 8, it is necessary to always apply an appropriate amount of the release agent while uniformly applying it, and therefore it is necessary to delicately control the application amount, resulting in poor workability and difficulty in automation. is there.

The present invention has been made in view of the above circumstances, and a molded product can be smoothly released from the mold even if the amount of the release agent applied is small, and even if the amount of the release agent applied is large. It is an object of the present invention to provide a cleaning blade that does not generate non-defective products and a mold for molding the cleaning blade.

[0006]

In order to achieve the above object, the present invention is a cleaning blade for removing toner adhering to a photosensitive drum, which is slidable with the photosensitive drum on one side edge along the longitudinal direction. A plate-shaped soft blade member in which a sliding contact portion is formed, and a plate-shaped holder provided on the other side edge side of the blade member, wherein the sliding contact portion of the blade member is one side edge of the blade member Is formed by a smooth strip-shaped portion formed along the longitudinal direction on one surface of the blade member including the corner portions of the blade member, and the one-sided portion of the blade member adjacent to the sliding contact portion is formed as a rough surface. The cleaning blade is the first gist, and the first and second molds in which the molding space for molding the blade member is formed on the mold surface are provided, and one side edge of the plate-shaped holder is projected into the molding space. In the state, the two molds are combined, a cleaning blade molding mold for integrally molding the blade member with the plate-shaped holder by injecting and curing a resin liquid into the molding space, in at least one molding space, A second aspect of the present invention is a cleaning blade molding die in which a wall surface portion corresponding to the sliding contact portion of the blade member is formed in a mirror surface portion, and the wall surface portion connected to the mirror surface portion is formed in a rough surface portion.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION That is, when the present inventors formed a part of a wall surface of a molding space in a rough surface portion in the course of conducting a series of research for the purpose of smoothly releasing a molded product, this rough surface It was recalled that the release agent is stored in the fine irregularities of the surface portion, which prevents the molded article from adhering to the wall surface, and that the release agent can be released smoothly even if the amount of the release agent applied is small. As a result of further research, when the rough surface portion is present on the wall surface of the molding space, an excess amount of the release agent is removed by the above-mentioned rough surface not only when the coating amount of the release agent is small but also when the coating amount is too large. The present invention was accomplished by finding out that the fine recesses on the surface of the molded product are prevented from entering the minute unevenness of the surface portion and not adhering to the mirror surface portion of the wall surface of the molding space in the form of water droplets.

Next, the present invention will be described in detail.

In the molding die of the present invention, the wall surface portion of at least one molding space of the above-mentioned die corresponding to the sliding contact portion of the blade member is formed as a mirror surface portion, and the wall surface portion connected to this mirror surface portion. Are formed on the rough surface portion.

Examples of the material of the die include carbon steel, carbon tool steel, high speed steel, die steel, forged die steel, high vanadium steel, alloy tool steel and case hardening steel, and various materials are used. .

The surface roughness of the rough surface portion is preferably set to Rz (ten-point average roughness) of 2.5 μm or more and 10 μm or less. That is, if the roughness is smaller than the above range, the surface of the molded product is likely to adhere to this rough surface portion and the demolding property is deteriorated. On the contrary, if the roughness is rough, it is injected after repeated use. This is because dirt such as slag of the resin liquid is clogged in the fine irregularities of the rough surface portion, which rather deteriorates the mold release property.

As a method for obtaining the rough surface portion, for example, sandblasting, etching or the like is performed on the surface of the mold material, but the method is not particularly limited and various methods are performed.

The surface roughness of the mirror surface portion is preferably Rmax (maximum roughness) of 1.0 μm or less. That is, if it exceeds 1.0 μm, the smoothness of the sliding contact portion of the blade member, which is a molded product, cannot be secured, and sufficient cleaning performance cannot be obtained.

Further, the cleaning blade of the present invention is
It is molded using the above molding die, and a smooth band-like portion formed by transferring the mirror surface portion of the above-mentioned die is formed on a sliding contact portion that is in sliding contact with the photosensitive drum on one edge side of the blade member. Then, a portion of one surface of the blade member adjacent to the sliding contact portion is formed as a rough surface by transferring the rough surface portion of the mold.

The width of the sliding contact portion is preferably set to 0.5 mm or more and 5 mm or less. That is, 0.5
If it is less than 5 mm, there is a risk of toner leakage from minute irregularities on the rough surface adjacent to the sliding contact portion. On the contrary, if it exceeds 5 mm, the width dimension of the rough surface is narrowed and the releasability deteriorates.

Next, examples will be described.

[0017]

FIG. 1 shows an embodiment of a cleaning blade molding die of the present invention. The cleaning blade molding die 13 includes an upper die 13a and a lower die 13b, and a molding space 7 for molding a blade member is formed on the die surface. Further, the cleaning blade molding die 13 is made of carbon steel, and covers a central portion of the inner surface 7a of the molding space 7 of the upper die 13a (that is, the sliding contact of the tip of the blade member, which is a molded product). Corresponding to the portion) is formed on the mirror surface portion 11.
Wall surface portions on both sides sandwiching are respectively formed on the rough surface portion 12.

Using the above-mentioned cleaning blade molding die, for example, a cleaning blade can be manufactured as follows. First, as shown in FIG. 2, the two plate-shaped holders 4 are positioned in the mold 13 and clamped. Then, a molding member made of urethane resin is injected into the molding space 7 and cured, and as shown in FIG.
The wide blade member 14 to which is fixed is removed from the mold. The wide blade member 14 has a central region of a side surface (upper side in the drawing) formed on a smooth surface 14a to which the mirror surface portion 11 of the upper mold 13a is transferred, and portions on both sides sandwiching the smooth surface 14a. Is formed on the rough surface 14b to which the rough surface portion 12 of the upper mold 13a is transferred. Next, the central portion (the position indicated by the chain line in FIG. 3) of the smooth surface 14a of the wide blade member 14 is cut and separated into two pieces as shown in FIG. 4 to obtain the cleaning blades 15, respectively.

In the cleaning blade 15 thus obtained, as shown in FIG. 5, the cut surface 20b at one side edge of the blade member 20 is formed into a smooth surface, and a sliding contact portion which is in sliding contact with the photosensitive drum. 20a is formed on a strip-shaped smooth surface to which the mirror surface portion 11 of the mold 13 is transferred. The corner portion 20c formed by the cutting surface 20b and the sliding contact portion 20a is formed in a state of being raised over its entire length. Further, the sliding contact portion 20
A part of one surface of the blade member 20 adjacent to a is formed as a rough surface 21 to which the rough surface portion 12 of the mold 13 is transferred. In this embodiment, the width dimension of the sliding contact portion 20a (F in FIG. 5) is set to 2.5 mm, and the rough surface 2
The width dimension of 1 (G shown in FIG. 5) is set to 7.5 mm.

When the cleaning blade 15 is used, as shown in FIG. 6, the sliding contact portion 20a and the corner portion 20c of the blade member 20 are slidably contacted with the photosensitive drum 1 in a state of being in close contact with each other so that the blade stands up. The toner can be sufficiently removed by scraping off the toner at the sharp corners 20c.

The mold release force of the urethane rubber molded product when the cleaning blade molding die of the present invention was used was measured. With respect to the demolding force, one end of the urethane rubber molded product 16 that has been injected and hardened and adhered to the wall surface of the mold 19 is sandwiched by the clip 18 by the measuring device shown in FIG. Mold 1 of urethane rubber molding 16
The peel strength from 9 was measured by a spring weigher 17.
The width dimension (A in FIG. 7) of the mold 19 was set to 20 mm, and the pulling speed was set to 30 mm / sec. In the figure, B is the width dimension of the mirror surface portion 11, and C is the width dimension of the rough surface portion 12.

First, the coating amount (film thickness) of the release agent is 0.3 μm.
m, the surface roughness (Rz) of the rough surface portion 12 was kept constant at 2.8 μm, and measurement was performed while changing the mirror surface portion width B dimension and the rough surface portion width C dimension. The results are shown in Table 1.

[0023]

[Table 1]

From the results shown in Table 1 above, it can be seen that in each of the examples, the demolding force was lower than that of the conventional example, and the urethane did not bend. The width B of the mirror surface is 10 mm.
The ones set below had a lower demolding force, and excellent results were obtained. In addition, when the dimension B of the mirror surface portion is less than 1 mm, the sliding contact portion 20a of the blade member 20 when made into a product.
The width becomes too small (that is, less than 0.5 mm), and when it is used in sliding contact with the photosensitive drum, the toner does not sufficiently adhere, and there is a risk of toner leakage.

Further, the coating amount (film thickness) of the release agent is 0.3 μm.
m, mirror surface width B dimension is 5 mm, rough surface width C dimension is 7.5
The surface roughness of the rough surface portion 12 (Rz, Rm
It was measured while changing ax) as shown in Table 2 below.
The results are shown in Table 3.

[0026]

[Table 2]

[0027]

[Table 3]

From the results shown in Tables 2 and 3 above, it can be seen that the mold releasing force of each example is lower than that of the conventional example. Particularly, the surface roughness (Rz) of the rough surface portion 12 is 2.5 μm or more 1
When the thickness was within the range of 0 μm or less, the demolding force was lower, the urethane did not bend, and excellent results were obtained. If it is less than 2.5 μm, the demolding force is slightly increased and the urethane bends. If it exceeds 10 μm, the demolding force increases with each repeated use, and if it exceeds 20 times,
Dirt such as urethane slag clogged in the minute irregularities on the rough surface, causing dirt on the rough surface.

Further, the surface roughness (Rz) of the rough surface portion 12 was kept constant at 2.8 μm, the width B of the mirror surface portion was 5 mm, and the width C dimension of the rough surface portion was kept constant at 7.5 mm. (Thickness) was changed and measured. The result is shown in FIG.

From the results shown in FIG. 8, it can be seen that in Example, even when the amount of the release agent applied was smaller than in the conventional example, the increase in the demolding force was small. In the conventional example, the mold release was possible within the range D shown in the figure, but in the example, the mold release is possible smoothly up to the range E shown in the figure.

[0031]

As described above, according to the cleaning blade molding die of the present invention, the wall surface portion of the molding space of at least one molding space corresponding to the sliding contact portion of the blade member is formed as the mirror surface portion. The wall surface portion connected to this mirror surface portion is formed in the rough surface portion. Therefore, even when the amount of the release agent applied to the wall surface of the molding space is small and the film thickness is too thin, the rough surface of the rough surface portion prevents the surface of the molded product from sticking to the mirror surface portion, and the mold release Sometimes this molded article does not deform or break. Further, even when the amount of the release agent applied is large and the film thickness is too thick, a large amount of the applied release agent is prevented from adhering to the mirror surface portion in the form of water droplets, and minute recesses are formed on the surface of the molded product. Does not happen. Therefore, in this mold, even if there is some variation in the release agent coating amount, defective products do not occur as in the past, so the coating amount can be controlled easily, workability is improved, and automation is improved. Will be possible.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a cleaning blade molding die of the present invention.

FIG. 2 is an explanatory view showing a manufacturing state of a cleaning blade using the cleaning blade molding die of the present invention.

FIG. 3 is an explanatory view showing the manufacturing state.

FIG. 4 is an explanatory diagram showing the manufacturing state.

FIG. 5 is a perspective view showing an example of a cleaning blade of the present invention.

FIG. 6 is an explanatory diagram showing a usage state of the cleaning blade.

FIG. 7 is an explanatory diagram showing a method for measuring demolding force.

FIG. 8 is a diagram showing the relationship between the amount of release agent applied and the demolding force.

FIG. 9 is an explanatory view showing a usage state of a conventional cleaning blade.

FIG. 10 is a perspective view showing a conventional cleaning blade.

FIG. 11 is an explanatory diagram showing a manufacturing state of a conventional example.

FIG. 12 is an explanatory diagram showing a manufacturing state of the conventional example.

FIG. 13 is an explanatory diagram showing a manufacturing state of the conventional example.

[Explanation of symbols]

4 plate holder 7 molding space 11 Mirror surface 12 Rough surface 13a Upper mold 13b Lower mold

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-8-174579 (JP, A) JP-A-3-284784 (JP, A) JP-A-59-68770 (JP, A) JP-A-63- 226683 (JP, A) JP 63-58481 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B29C 39/00-39/44 G03G 21/00

Claims (5)

(57) [Claims] 1. A cleaning blade for removing toner adhering to a photosensitive drum, comprising: a plate-shaped soft blade member having a sliding contact portion which is in sliding contact with the photosensitive drum on one side edge along the longitudinal direction. , A plate-shaped holder provided on the other side edge side of the blade member, the sliding contact portion of the blade member including a corner of one side edge of the blade member in the longitudinal direction on one surface of the blade member. A cleaning blade, characterized in that it is formed by a smooth strip-shaped portion formed along the side surface, and a portion of one surface of the blade member adjacent to the sliding contact portion is formed as a rough surface. 2. The width dimension of the sliding contact portion is 0.5 mm or more and 5 m.
The cleaning blade according to claim 1, which is not more than m. 3. The first and second molds, each having a molding space for molding a blade member formed on a mold surface, wherein both side edges of the plate-shaped holder are projected into the molding space. A mold for molding a cleaning blade for integrally molding a blade member with the plate-shaped holder by injecting and curing a resin liquid into the molding space, and sliding the blade member in at least one molding space. A cleaning blade molding die characterized in that a wall surface portion corresponding to a contact portion is formed on a mirror surface portion, and the wall surface portion connected to the mirror surface portion is formed on a rough surface portion. 4. The cleaning blade molding die holds the pair of plate-shaped holders in the molding space in a state in which one side edge portions of the pair of plate holders are abutted with each other while keeping a predetermined space, and the resin liquid is held in the molding space. A wall surface portion of the molding space corresponding to the sliding contact portion of the blade member formed at one side edge portion of both plate-shaped holders is formed into a mirror surface portion, and the wall surfaces on both sides sandwiching this mirror surface portion. The cleaning blade molding die according to claim 3, wherein the portion is formed on a rough surface portion. 5. The surface roughness of the rough surface portion is 2.5 μm in Rz.
The cleaning blade molding die according to claim 3, having a size of 10 μm or more.