JPH0615373B2 - Paper sheet conveyor belt and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of the Invention The present invention is a plain paper copier (hereinafter, abbreviated as PPC copier).
TECHNICAL FIELD The present invention relates to a rubber endless belt which can be suitably used for conveying paper sheets in a machine, a facsimile machine, and the like, and particularly to an improved structure and manufacturing method thereof.

[Prior art]

The PPC copiers currently on the market have some mechanical differences depending on the manufacturer, but the principle is as abbreviated in FIG. Explaining with reference to the figure, when a document is first set and a start button (not shown) is pressed, the base paper (P) is fed from the one-sheet cassette (C) to the pair of timing rolls by the paper feed roll (R). After being fed to (T, T), the starting end of the photosensitive surface (S) of the photosensitive drum (D) is held between the rolls (T) and (T) so that It is kept waiting until it reaches the position directly above (the position shown in the figure).

Next, when the starting end of the photosensitive surface (S) reaches the position shown in the figure, the timing rolls (T) and (T) rotate and the base paper (P) is sent out onto the conveyor belt (A). While (P) is being conveyed by the belt (A), desired characters or figures made of a printing material such as carbon are transferred from the photosensitive surface (S) to the surface thereof.

The base paper (P) is further fed between the pair of fixing rolls (B, B) by the conveyor belt (A), and characters or figures on the surface are fixed by heating while passing between the rolls.

As is clear from the above, once the timing roll (T,
The base paper (P) sent to the copy area directly below the photosensitive drum (D) by T) has a printing material such as carbon for displaying the characters, figures, etc. transferred onto its one surface, and therefore has not been fixed yet. Until it passes between the fixing rolls (B, B), it is placed on the conveyor belt (A) and moved depending on the surface frictional force of the belt. Therefore, if the base paper (P) does not move at the same speed as the belt (A) due to the surface frictional force of the conveyor belt (A),
A "shrinkage" along the traveling direction of the base paper occurs as shown in FIG. 3B in the transferred characters or figures. It should be noted that FIG. 9A shows the printed characters that are normally transferred.

As shown in FIG. 2B, the upper conveyor belt (A) is usually stretched in parallel between a pair of transfer shafts (E, E) in a plurality of columns. If the surface frictional force is different between them, the base paper (P) conveyed by the belt will be displaced, and as a result, the image surface transferred onto the paper surface will also be distorted.

Therefore, in a conventional PPC copying machine or the like, a vacuum suction device (V) or the like is installed from below the belt (A) so that the base paper (P) can be moved in a state of being in close contact with the surface of the conveyor belt (A) as much as possible. The method of suction is adopted. A plurality of ventilation small holes (not shown) are formed in the conveyor belt (A) so that the suction force effectively acts on the base paper.

[Problems to be solved]

By the way, while the base paper (P) passes through the vacuum suction area, each ventilation small hole of the conveyor belt (A) is sealed by the base paper (P), so that the belt (A) is a surface of the vacuum suction device. Is strongly attracted to the rotary shaft (E,
Orbital movement is performed by E). Therefore, it is preferable that the coefficient of friction on the side where the conveyor belt (A) faces the vacuum suction device is as low as possible, and if the coefficient of friction is high,
In connection with the hardness of the rubber forming the belt (A), wrinkles are formed on the belt or a meandering phenomenon occurs. It goes without saying that these inconvenient phenomena adversely affect the transporting action of the base paper (P), and eventually the finish of the image. Therefore, in the conventional device, the surface of the belt (A) or the surface of the vacuum suction device is coated with a low-friction resin such as tetrafoloethylene, and the suction edge of the vacuum suction device has a slightly raised opening edge. Some of them adopt a method of preventing adsorption to the suction port by forming them, but it takes extra time and labor for the slippery processing with such a heterogeneous material, and the leaf slippery material. Are generally expensive.

[Object of the Invention]

The present invention solves the above-mentioned problems in the conventional conveyor belts of PPC copying machines and the like, and exerts a high surface friction action on the base paper and a low friction action on the surface of the vacuum suction device. It is possible to provide a paper sheet conveyor belt having excellent resistance to the tensile force that accompanies the orbiting motion and a simple manufacturing method thereof, and to provide characters and figures in a copying machine or a facsimile machine. The purpose is to increase the fidelity of copying or electronic transmission.

[Specific means]

In order to achieve the above object, the paper sheet conveying belt according to the present invention is characterized by having a chlorinated surface layer on one surface of a rubber belt having a friction coefficient μ of 1.0 or more.

As described above, since the conveyor belt is rotated by the rotating shaft stretched between the pair of rotating shafts, a tensile force acts on the belt in the longitudinal direction. Therefore, the belt also needs to have excellent tensile low structure. Therefore, the rubber belt constituting the conveyor belt has a hardness (JIS
A) is adjusted to be about 50 or more and about 70 or less. The rubber hardness is closely related to the friction coefficient μ, and the hardness is 50, the friction coefficient is about 1.5, and the hardness 70 is about 1.0. When the rubber hardness is 50 or less, the belt is too soft and wrinkles occur in the belt due to the tensile action of the rotating shaft, and when the hardness is 70 or more, the belt is too hard and the rotating shaft is intimately adhered to the rotating shaft. Will work. Therefore, it is preferable that the hardness is 60 practically, and the surface friction coefficient μ in that case is about 1.2.
Is. Of course, the higher the surface friction coefficient μ on the surface of the rubber belt that comes into contact with the paper to be conveyed, the better if it is about 1.0 or more. Occurs and the tensile strength is reduced. In order to avoid such an inconvenient situation, it is preferable to embed a fiber reinforcing layer in the rubber belt.

Fully, the friction coefficient of the chlorinated surface layer of the rubber belt μ
Is 0.5 or less, preferably in the range of 0.5 to 0.3. If it is less than 0.3, slip will occur with the rotating shaft.

According to the present invention, the vulcanized rubber hardness (JIS A) is about 70 in order to most efficiently manufacture the paper sheet conveying belt having the above structure.
After molding a rubber belt using the rubber composition prepared as follows, the rubber belt was subjected to a predetermined amount in a chlorine solution so that the surface friction coefficient μ of the rubber belt was in the range of 0.5 to 0.3. A method of immersing for a time and then polishing one surface of the belt to remove the chlorinated surface layer is adopted. By polishing the chlorinated surface, one surface of the rubber belt having a surface friction coefficient μ of about 1.0 or more appears as described above.

Instead of the above-mentioned manufacturing method, a method of applying a chlorine solution to one surface of a rubber belt made of a rubber composition prepared so that the vulcanized rubber hardness (JISA) is about 70 or less and chlorinating the surface layer is adopted. You can also

[Action / effect]

As described above, the paper sheet conveying belt according to the present invention has a friction coefficient μ of 1.0 or more, preferably in the range of 1.0 to 1.5,
It preferably has a front surface of about 1.2 and a back surface of which the surface layer is chlorinated so that the friction coefficient μ is in the range of 0.5 to 0.3. By arranging the shaft and the vacuum suction device on the side in contact with the suction opening surface and stretching between the rotary shafts, an excessive torque is not applied to the rotary shaft, and the suction force by the vacuum suction device is increased. On the other hand, it can slide smoothly along the suction / suction opening surface, but it has a good frictional effect on the sheets conveyed on the belt and is combined with the suction effect of the vacuum suction device. Thus, the paper sheets can be normally conveyed without being displaced.

〔Example〕

 Examples of the present invention will be described below.

[Embodiment 1] FIG. 1 is a perspective view of a conveyor belt for a PPC copying machine according to an embodiment of the present invention. The conveyor belt (1) of the present example is first prepared by using an injection molding device equipped with a cylindrical medium mold as disclosed in JP-A-60-127113 and using a chloroprene rubber composition having the following composition, 1 mm. JIS
After forming a rubber belt having an A hardness of 60, the rubber belt is immersed in a liquid tank filled with a chlorine solution (chlorine water) having a concentration of 0.1% for about 15 minutes to chlorinate the surface, and then one surface of the belt is The surface layer portion chlorinated by buffing is scraped off, and finally, a plurality of ventilation small holes for vacuum suction (4, 4, ...・) Was completed through each process of drilling.

[Composition] [Parts by weight] Chloroprene rubber 100.0 Carbon black 50.0 Softening agent 10.0 Activator 4.0 Lead phosphite 3.0 Stearic acid 1.0 Anti-aging agent 1.0 Processing aid 0 1 Iow 0.5 Accelerator A 1.0- 〃- B 1.0 171.6 The thus obtained conveyor belt (1) of this example is HEIDON-10 type static friction coefficient manufactured by Shinto Scientific Co., Ltd. As a result of measuring the initial friction coefficient when not in use and the friction coefficient after use, the friction coefficient μ of the surface (2) when not in use and after use was 1.2 and chlorinated. Back side
The friction coefficient μ of (3) was 0.3 in all cases.

The conveyor belt (1) of this example was actually mounted on a PPC copying machine and subjected to a practical test. As a result, defective images such as “shrink” or “bias” shown in FIG. Did not occur at all. This fact indicates that the belt (1) of the present example has a revolving motion due to the suction between the surface (2) of the belt (1) and the copy sheet, and the suction between the belt (1) and the suction opening surface of the vacuum suction device. It means that no malfunctions such as stagnation or slip between the belt (1) and the rotating shaft occurred. Further, the tension retention rate after the rotation of 3 million times was 85%.

[Example 2] In the rubber compound used in Example 1,
To manufacture a rubber belt having a rubber hardness (JIS A) of 70 by changing the compounding amount of carbon black to 100 parts by weight of rubber to 80 parts by weight, and to shorten the immersion time of the rubber belt in chlorine water to 5 minutes. This is different from that of Example 1 in that the coefficient of friction of the chlorinated back surface (3) was adjusted to 0.5. The coefficient of friction of the surface (2) of the conveyor belt (1) of this example was measured and found to be 1.0. In the practical test of the belt of this example, a squeaking noise was occasionally heard, but no "shrink" or "bias" of the copied image was observed.

Example 3 In this example, the rubber hardness (JIS) was changed by changing the compounding amount of carbon black to 20 parts by weight in the rubber compounding of Example 1.
Example 1 except that a rubber belt having A) of 50 was manufactured.
It was made in the same way as the original. The friction coefficient of the surface (2) of the belt of this example was 1.5, and the result of the practical test was as good as that of the previous two examples.

[Comparative example]

The rubber hardness (JIS A) was set to 4 by setting the compounding amount of carbon black in the rubber compounding of Example 1 to 10 parts.
A conveyor belt completed in the same manner as in Example 1 except that the rubber belt No. 5 was manufactured, and a practical test was performed in combination with the conveyor belt manufactured in Example 1. As a result, a copy image was obtained. There were some cases in which "bias" (see Fig. 3 (c)) occurred. Therefore, the improvement as in Example 4 was tried. The friction coefficient of the surface (2) of the belt of this example is 1.
It was 6.

[Example 4] A rubber belt is manufactured by using a rubber material having a carbon black content of 10 parts by weight, which is the same as the comparative example, except that a woven fabric of polyethylene terephthalate fiber is embedded in the rubber belt. Thus, a conveyor belt different from that of the comparative example in that the elongation resistance in the longitudinal and lateral directions of the belt was reinforced was manufactured. 5% of the belt of this example is put to a practical device (PPC copier) equipped with a rotary shaft with a tensioner.
As a result of carrying out a practical test by stretching in a state in which the initial strain was applied, the defects of the conveyor belt of the comparative example were completely eliminated, and good copying results were obtained. From this example, even if the rubber hardness is made as low as possible in order to increase the friction coefficient, if the elongation resistance of the belt is enhanced by embedding a reinforcing layer in the belt, it is sufficient to achieve the object of the present invention. It turns out that a simple conveyor belt is manufactured.

Example 5 A rubber belt similar to that of Example 1 (hardness 60 °, friction coefficient 1.2) was manufactured, and a solvent solution of a chlorine organic compound (Rohm and Haas "Chemlock" was manufactured on the back surface (3) of the rubber belt. 701) is applied several times to the surface
The surface layer of (3) was chlorinated (friction coefficient -0.3) to make a conveyor belt. As a result of the practical test, good copying could be performed without shrinkage or distortion of the copying material.

〔The invention's effect〕

The present invention, as described above with reference to several examples,
When a sheet of paper is transported in a PC copying machine or facsimile machine, a high surface friction action can be exerted on the sheet and a low friction action can be exerted on the surface of the vacuum suction device. Provided is a paper sheet conveying belt having excellent resistance to a tension received, and a simple manufacturing method thereof, thereby increasing the fidelity of copying or electric transmission of characters and figures in the above devices. .

[Brief description of drawings]

FIG. 1 is a perspective view of a rubber conveyor belt according to an embodiment of the present invention, FIG. 2 is a schematic explanatory view showing the structure of a copying machine in which the belt of the present invention is used, and FIG. 3 shows an example of a copied image. It is a partial top view. In each drawing, the meanings of the symbols are as follows; -1: the entire conveyor belt, 2: the front surface of the belt (1), 3: the back surface of the belt (1), 4: ventilation small holes.

Claims (7)

[Claims] 1. A paper sheet conveying belt having a chlorinated surface layer on one surface of a rubber belt having a friction coefficient μ of 1.0 or more. 2. The paper sheet conveying belt according to claim 1, wherein the chlorinated surface layer has a friction coefficient μ of 0.5 or less. 3. The rubber hardness (JISA) of the rubber belt is about 70.
The paper sheet conveying belt according to claim 1 or 2, which is as follows. 4. The paper sheet conveying belt according to any one of claims 1 to 3, wherein the rubber belt has a reinforcing fiber layer embedded therein. 5. A step of molding a rubber belt using a rubber composition adjusted to have a vulcanized rubber hardness (JIS A) of about 70 or less, and a step of chlorinating the surface layer on one surface of the molded rubber belt. A method for manufacturing a paper sheet conveyor belt, which comprises: 6. The method of chlorinating the surface layer on one side of a rubber belt comprises immersing the belt in a chlorine solution and then polishing the surface of the belt to remove the chlorinated surface layer. A method for producing a paper sheet conveying belt according to claim 5. 7. The method of manufacturing a paper sheet conveying belt according to claim 5, wherein the step of chlorinating the surface layer on one surface of the rubber belt is performed by applying a chlorine solution to the one surface of the belt.