JP2003292187A - Paper feeding conveying roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding conveying roller having high durability while lowering its hardness, capable of stably keeping its coefficient of friction without affected by paper powder, and free from noise. <P>SOLUTION: This paper feeding conveying roller used in feeding or conveying sheets, comprises an inner layer 12 formed at a core metal 11 side and composed of a foamed elastic body, and an outer layer 13 formed on the inner layer, and composed of a low-foamed elastic body of a foaming magnification lower than that of the foamed elastic body. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding / conveying roll used for various sheet feeding / conveying rolls of various office automation equipment such as copiers, facsimiles and various printers.

[0002]

2. Description of the Related Art Conventionally, rolls for feeding and carrying various OA equipment are required to have a great carrying force and excellent wear resistance. For this reason, EPDM has been conventionally used.
A material having excellent mechanical strength and a high friction coefficient such as (ethylene / propylene / diene rubber) or chlorinated polyethylene rubber, silicone rubber or polyurethane rubber is used as a material for the roll.

Such a paper feeding / conveying roll has a problem that the rate of change in the friction coefficient is large due to the influence of paper dust or the like due to long-term use and the durability is poor, and the friction with the paper or the like at the time of paper feeding. There is a problem in that a so-called squeal phenomenon occurs due to the vibration caused by.

[0004]

Therefore, it has been proposed to prevent squeal by adding a plasticizer or the like to reduce the hardness. However, in such a method of reducing the hardness, compression is performed. Permanent strain decreases, paper feeding capacity decreases,
Also, there arises a problem that wear resistance is lowered and durability is lowered.

On the other hand, it is possible to use a foamed elastic body to reduce the hardness, but there is a problem in terms of durability.

In view of this, in Japanese Patent Laid-Open No. 2001-341862, there are two layers, an inner layer of a foamed elastic body and an outer layer of a non-foamed elastic body.
A paper feed roll formed of a layered structure has been proposed. Since this paper feed roll has a foamed elastic body in the inner layer, it has a lower hardness as a whole than the single-layer structure of a non-foamed elastic body and can secure a large nip amount to obtain stable paper feeding performance and to be durable. Abrasive performance depends on the layer of non-foamed elastomer.

However, since the surface of the two-layer roll is a non-foamed elastic body, there remains a problem that the friction coefficient is apt to decrease with time due to the influence of the paper powder as described above.

In view of such circumstances, the present invention has a low hardness and an excellent durability, can maintain a stable friction coefficient without being affected by paper dust, and does not cause squeaking. An object is to provide a transport roll.

[0009]

A first aspect of the present invention for solving the above-mentioned problems is a paper feed / conveyance roll used for feeding or conveying paper sheets, which is provided on the core metal side and is foamed. A paper feed / conveyance roll comprising an inner layer made of an elastic body and an outer layer formed on the inner layer and made of a low-foaming elastic body having a foaming ratio lower than that of the foaming elastic body.

A second aspect of the present invention is the sheet feeding / conveying roll according to the first aspect, further comprising an adhesive layer between the inner layer and the outer layer.

A third aspect of the present invention is the sheet feeding / conveying roll according to the first or second aspect, characterized in that a thin rubber elastic layer is provided between the core metal and the inner layer. It is in.

In a fourth aspect of the present invention, in any one of the first to third aspects, the low expansion elastic body has a foaming ratio of 1.0.
It is a roll for feeding and feeding characterized by being 5 to 1.5 times.

A fifth aspect of the present invention is the sheet feeding roll according to any one of the first to fourth aspects, wherein the foaming elastic body has a foaming ratio of 1.8 times or more. .

In a sixth aspect of the present invention, in any one of the first to fifth aspects, the foamed elastic body has an average cell diameter of 15
It is a roll for feeding and feeding characterized in that it is 0 μm or more.

Here, the foamed elastic body of the inner layer and the low foamed elastic body of the outer layer of the paper feed / conveyance roll of the present invention are made of a conventionally known material selected from various foamed rubbers and foamed thermoplastic elastomers. be able to. Specifically, E
A rubber material such as PDM, NBR, SBR, NR, or a polyurethane rubber, or a thermoplastic elastomer material such as a polyethylene-based or polystyrene-based elastomer can be used.

The expansion ratio of the foamed elastic body of the inner layer is preferably 1.8 times or more. Further, the expansion ratio of the low foam elastic body of the outer layer is preferably 1.05 to 1.5 times, more preferably 1.1 to 1.2 times. The expansion ratio can be adjusted by applying the amount of the foaming agent and applying pressure during foaming.

The foamed elastic body of the inner layer and the low foamed elastic body of the outer layer may be continuous cells or closed cells, but the foamed elastic body of the inner layer has an average cell diameter of 150 μm or more, preferably from the viewpoint of vibration absorbing performance. It is preferable to use one having a thickness of 250 μm or more.

In the paper feed / conveyance roll of the present invention, the total rubber hardness of the foamed elastic body of the inner layer and the low foamed elastic body of the outer layer is 5 ° to 40 ° in JIS A. With such a two-layer structure and a rubber hardness of 5 to 40 according to JIS A.
Due to the low hardness and low hardness, it is possible to obtain a large amount of deformation (nip amount) under a constant pressure load to maintain the feeding and transporting characteristics, and to obtain high vibration absorption performance without lowering durability. , Can effectively prevent squeaking. Further, since the outer layer is a low-foamed elastic body and has a high specific gravity, it is a roll for feeding and conveying which has better wear resistance than the foam single-layered product. Further, since the outer layer is a foam, the surface roughness is large, and a predetermined initial friction coefficient is obtained even if the overall rubber hardness of the inner layer and the outer layer described above is low. The paper transport characteristics can be maintained, and the reduction of the friction coefficient due to the paper dust, which has been a problem in the past, can be suppressed by the paper dust and the like adhering to the surface entering the concave portion of the foam.

The paper feed / conveyance roll of the present invention can also be used for paper feed / conveyance of recycled paper or the like containing aluminum oxide, calcium carbonate, titanium oxide and silica components.
It is needless to say that the paper feeding / conveying roll of the present invention has the same effect as or better than the conventional roll even when paper sheets other than recycled paper are used.

The paper feed / conveyance roll of the present invention may have an adhesive layer between the inner layer and the outer layer. As the material of the adhesive, for example, when the material of the inner layer and the outer layer is EPDM, an EVA hot melt adhesive can be used.

Further, in the paper feeding / conveying roll of the present invention, the inner layer made of the foamed elastic body described above may be directly provided on the cored bar, but in order to prevent slipping between the inner layer and the cored bar. Alternatively, a thin rubber elastic layer may be provided on the cored bar.

It should be noted that each layer may be provided with conductivity, and by doing so, it is possible to prevent the generation of static electricity during sheet feeding and conveyance.

In the paper feed / conveyance roll of the present invention, an inner layer made of a foamed elastic body is provided on a cored bar or a thin rubber elastic layer provided on the cored bar, and then a low foamed elastic body is provided outside the inner layer. Between the outer layer made of low foam elastic body and the outer layer made of low foam elastic body and the core metal or the thin rubber layer provided on the core metal after preforming the outer layer made of low foam elastic body. Alternatively, an inner layer made of a foamed elastic material may be provided.

In any case, it is preferable that the respective layers are joined by vulcanization adhesion when the last rubber material is vulcanized through an adhesive, if necessary, and if necessary, preformed. It is preferable to mold the next layer in a state where the layer is semi-vulcanized and to perform vulcanization adhesion when vulcanizing this layer. The term "semi-vulcanized" refers to vulcanization of about 50 to 90% of total vulcanization.

Here, in order to provide each layer concentrically with the cored bar as the center, a tube of an outer layer made of a low-foamed elastic body is preformed in a state where the inner diameter is defined, and then this tube is placed outside the cored bar. It is preferable to use a manufacturing method in which the raw material for the inner layer made of the foamed elastic body is filled in between and the foaming is performed.

As for the material of each layer, it is preferable to select a material that allows each layer to be easily joined, and it is preferable to select a material of the same kind or a material that is easily compatible with each other. When the thin rubber-like elastic layer is provided on the core metal, it is preferably formed by applying a solution in which a rubber material is dissolved in a solvent.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to Examples, but these Examples do not limit the scope of the present invention in any way.

FIG. 1 shows a cross section of a sheet feeding / conveying roll according to one embodiment. As shown in FIG. 1 (a), the paper feeding / conveying roll 10 comprises a cored bar 11 on which an inner layer 12 made of a foamed elastic body and an outer layer 13 made of a low foamed elastic body are sequentially provided.

The inner layer 12 made of a foamed elastic body is made of a foamed body having a foaming ratio of 1.8 times or more and a thickness of 1 mm to 6 mm, and the outer layer 13 made of a low foamed elastic body has a foaming ratio of 1.0.
It is made of a foam having a thickness of 5 to 1.5 times and a thickness of about 0.3 mm to 3 mm.

As shown in FIG. 1B, the inner layer 12
A sheet feeding / conveying roll 10A may be provided with an adhesive layer 14 between the outer layer 13 and the outer layer 13, and as shown in FIG.
Between the cored bar 11 and the inner layer 12, a thin rubber elastic layer 15
1D may be used, and as shown in FIG. 1D, a thin rubber elastic layer 15, an inner layer 12, an adhesive layer 14, and an outer layer 13 are sequentially provided on a cored bar 11. The provided paper feed / conveyor roll 10C may be used.

An example of manufacturing such a sheet feeding / conveying roll 10 will be described with reference to FIG.

First, as shown in FIG. 2 (a), a foamed tube member 13 to be an outer layer 13 made of a low foam elastic material.
a is extruded in advance, covered with a cored metal 16 having a predetermined diameter, and half-vulcanized by heat treatment.
3a is demolded.

Next, as shown in FIG. 2 (b), the second mold 22 for closing the bottom surface is set on the cylindrical first mold 21, and the tube member 13a is formed inwardly and before the foaming is performed on the periphery. With the cored bar 11 having the inner layer 12a made of a foamed elastic material wound therein, the upper end is closed by the third mold 23. By heat-treating in this state, the inner layer 12a made of the foamed elastic body before foaming is foamed, and the tube member 13a is completely vulcanized to integrally mold both.

After that, the outer peripheral surface of the tube member 13a is ground to adjust the outer diameter and the core deviation, and the paper feeding / conveying roll 1
It was set to 0.

(Examples 1 to 3) As shown in Table 1 below,
Example 1 having an outer diameter of 25 mm and a width of 20 mm was changed by changing the foaming ratio of the inner layer (thickness 4 mm) made of the foamed elastic body and the outer layer (thickness 2 mm) made of the low foamed elastic body.
No. 3 paper feed / conveyor rolls were manufactured. The total rubber hardness and friction coefficient are also shown in Table 1.

(Comparative Example 1) As shown in Table 1 below, a foamed elastic single layer having a thickness of 6 mm, an outer diameter of 25 mm and a width of 20 m.
m sheet feeding and conveying rolls were manufactured. The total rubber hardness and friction coefficient are also shown in Table 1.

(Comparative Example 2) As shown in Table 1 below, a non-foamed elastic single layer having a thickness of 6 mm, an outer diameter of 25 mm and a width of 20 mm.
mm feed rolls were manufactured. The total rubber hardness and friction coefficient are also shown in Table 1.

(Test Example 1) A paper was fed from the roll paper 20 along the surface of the base 30 by the abrasion tester shown in the schematic view of FIG. The amount of wear when the roll 10 is rotated and fed and fed is
The paper feeding / conveying rolls of Examples 1 to 3 and Comparative Examples 1 and 2 were examined. The roll paper 20 is fed at a feed speed of 1 mm / sec, and the paper feed roll 1
The number of revolutions of 0 was set to 250 rpm, and the amount of wear after 30,000 revolutions was examined. The results are shown in Table 1.

As shown in Table 1, it was found that the wear amount of the example was smaller than that of the comparative example and the wear resistance was high.

(Test Example 2) Examples 1 to 3 and Comparative Example 1,
150,000 sheets (150K) using 2 paper feed rolls
Was continuously fed and the occurrence of squeaking was investigated. The results are shown in Table 1. In addition, ◎ means that no squeaking occurred at all, ○ means that no squeaking occurred, and △ means that squeaking occurred occasionally.
The case where the squeaking always occurred was evaluated as x.

As shown in Table 1, in Examples 1 to 3, no squeaking occurred.

(Test Example 3) Examples 1 to 3 and Comparative Example 1,
150,000 sheets (150K) using 2 paper feed rolls
Was continuously fed and the change in friction coefficient was investigated.

As shown in Table 1, the rolls of Examples 1 to 3 showed less decrease in friction coefficient than the rolls of Comparative Example.

[0044]

[Table 1]

[0045]

As described above, according to the present invention,
It is possible to provide a paper feed / conveyance roll that is excellent in durability while achieving low hardness, can maintain a stable friction coefficient without being affected by paper dust, and does not cause squeaking.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a sheet feeding / conveying roll according to an embodiment of the present invention.

FIG. 2 is a schematic view showing an example of a manufacturing process of a sheet feeding / conveying roll of the present invention.

FIG. 3 is a schematic view showing an abrasion tester of Test Example 1.

[Explanation of symbols]

10 Paper feed roll 11 core 12 Inner layer 13 outer layer 14 Adhesive layer 15 Rubber-like elastic layer 16 cored core 20 roll paper 30 units

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Claims (6)

[Claims] 1. A paper feed / conveyance roll used for feeding or conveying paper sheets, comprising an inner layer made of a foamed elastic body on the core metal side, and the foamed elastic body provided on the inner layer. A roll for feeding and feeding a sheet, comprising an outer layer made of a low-foaming elastic body having a low foaming ratio. 2. The paper feed / conveyance roll according to claim 1, further comprising an adhesive layer between the inner layer and the outer layer. 3. The sheet feeding / rolling roll according to claim 1, further comprising a thin rubber-like elastic layer between the core metal and the inner layer. 4. The sheet feeding / conveying roll according to claim 1, wherein the low expansion elastic body has a foaming ratio of 1.05 to 1.5. 5. A sheet feeding / conveying roll according to claim 1, wherein the foaming elastic body has a foaming ratio of 1.8 times or more. 6. The sheet feeding / conveying roll according to claim 1, wherein the foamed elastic body has an average cell diameter of 150 μm or more.