JP2001080776A - Paper sheet separating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper sheets separating device restricting dispersion of coefficient of friction and operation noise. SOLUTION: This separating device is formed of a friction layer 2, a first viscous layer 3, a foaming layer 4 and a second viscous layer 5. A coefficient of friction between the friction layer 2 and a paper sheet is set at 1.0-1.3, and hardness (Shore A) of the friction layer 2 is set at 70 or more. The first viscous layer 3 is made of the viscous agent, and the friction layer 2 and the foaming layer 4 are bonded to each other by this first viscous layer 3. The foaming layer 4 is formed of the foam and a base material (parts except for the foam). As the foam, continuous foam or separate foam can be used. The second viscous layer 5 is made of the viscous agent, and a paper sheet separating device 1 is fixed to a tray by the second viscous layer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper sheet separator used for a paper feeding mechanism of a copying machine, a printer, a facsimile or the like.

[0002]

2. Description of the Related Art In a paper feed mechanism, paper sheets such as PPC paper and OHP paper are stored in a tray, and the paper sheets are sent to an image forming mechanism by a paper feed roller or the like. The coefficient of friction between the paper feed roller and the paper sheets needs to be relatively large. Specifically, the coefficient of friction between the sheet and the paper feed roller must be larger than the coefficient of friction between the sheets. As a result, the sheets are surely separated one by one and sent to the image forming mechanism, so that a so-called double feed is prevented.

In this paper feed mechanism, no matter how large the coefficient of friction between the paper sheets and the paper feed roller is, if the number of remaining paper sheets in the tray becomes small (for example, about several sheets), the remaining paper sheets will be lost. All leaves may be sent at once and double feeds may occur. This is because the sheets are not separated one by one because the coefficient of friction between the tray and the sheets is smaller than the coefficient of friction between the sheets. In order to prevent double feeding when the number of remaining sheets is small, it is necessary that the coefficient of friction between the tray and the sheets is relatively large.

However, if the coefficient of friction between the tray and the sheet is too large and becomes larger than the coefficient of friction between the paper feed roller and the sheet, the last sheet in the tray cannot be fed and the so-called tray The rest will occur. In order to prevent the tray from remaining, it is necessary that the coefficient of friction between the tray and the sheet is smaller than the coefficient of friction between the sheet feeding roller and the sheet. That is, in this type of paper feeding mechanism, in order to prevent the double feed and the tray from remaining at the same time, the friction coefficient μF between the paper feeding roller and the paper sheet and the friction coefficient μR between the tray and the paper sheet are required.
And the friction coefficient μP between the paper sheets needs to be in a relationship represented by the following equation μF>μR> μP --- (I).

[0005] The tray is usually made of synthetic resin. Since the surface of the synthetic resin molded body has a small friction coefficient, it is difficult to set μR in the range of the above formula (I) in a tray made of a synthetic resin alone. As a tray having an increased μR, a tray in which a paper sheet separator made of synthetic leather is adhered to a tray substrate surface is used. Since the surface of the synthetic leather is appropriately fluffed, μR is adjusted by the fluffing.

[0006] Rubber sheets have been proposed and become the mainstream as a more industrial paper sheet separator. The surface of the rubber sheet is polished to increase the surface roughness. By increasing the surface roughness, a sharp decrease in the coefficient of friction can be suppressed even when the surface is worn by use in the paper feeding mechanism. Such a paper sheet separator is disclosed in, for example,
170,348 and the like.

[0007]

However, in the paper sheet separator made of synthetic leather, the degree of fluffing varies, so that the friction coefficient varies, and μR falls out of the range represented by the above formula (I). It may come off. On the other hand, in a paper sheet separator made of a rubber sheet,
Although variation in the coefficient of friction is suppressed, there is a problem that vibrations are generated by rubbing with paper sheets, and peripheral members resonate to generate unpleasant operation sounds, which adversely affects the office environment.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a paper sheet separator having a small friction coefficient variation and a small operation sound.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention has a foamed layer containing air bubbles, and a friction layer located on the front side of the foamed layer. Is 0.1 mm or more and 1.0 mm or less, the friction layer contains a polymer as a main component, and the friction layer has a Shore A hardness of 70 or more.

[0010] This paper sheet separator has a friction layer mainly composed of a polymer, and the friction layer rubs with the paper sheet. Small variation in friction coefficient. Further, since the paper sheet separator has a foam layer containing bubbles, the foam layer absorbs vibration generated in the friction layer. Therefore, the volume of the operation sound coming out of the sheet separating mechanism is suppressed.

Preferably, the ratio of the friction coefficient between the friction layer and the paper to the friction coefficient between the paper and the paper, that is, the relative friction coefficient between the friction layer and the paper when the friction coefficient between the paper and the paper is 1.0. The typical friction coefficient is 1.0 or more and 1.3 or less. Thereby, the friction coefficient as a whole of the paper sheet separator in which the foam layer is laminated on the friction layer becomes 1.0 or more and 1.5 or less. Therefore, double feeding of paper sheets and remaining trays are prevented.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Embodiments of the present invention will be described in detail. FIG. 1 is a cross-sectional view illustrating a paper sheet separator 1 according to one embodiment of the present invention. The paper sheet separator 1 includes a friction layer 2, a first adhesive layer 3,
It is composed of a foam layer 4 and a second adhesive layer 5.

The friction layer 2 is a layer that comes into direct contact with the paper sheet, and rubs with the paper sheet during paper feeding. The friction layer 2 is formed from a crosslinked rubber. As the rubber used, natural rubber, EPDM, butadiene rubber, styrene butadiene rubber, isoprene rubber, acrylonitrile-butadiene rubber, ethylene-propylene rubber, chloroprene rubber, acrylic rubber, chlorosulfonated polyethylene rubber, urethane rubber, polysulfide rubber, Epichlorohydrin rubber, silicone rubber, fluorine-based rubber, butyl rubber and the like can be mentioned, and these can be used alone or as a blend of two or more. Instead of rubber, a thermoplastic elastomer, a composite of rubber and synthetic resin, or the like may be used.

When the friction coefficient between paper and paper is set to 1.0, the friction coefficient between the friction layer 2 alone and paper is 1.0 or more.
It is preferably 3 or less. Thereby, the friction coefficient between the entire paper sheet separator 1 including the first adhesive layer 3, the foam layer 4, and the second adhesive layer 5 and the paper becomes 1.0 or more and 1.5 or less. By setting the friction coefficient between the friction layer 2 alone and the paper to be 1.0 or more,
The coefficient of friction between the entire paper sheet separator 1 and the paper becomes 1.0 or more, and double feeding of paper sheets is prevented. Conversely, when the friction coefficient between the friction layer 2 alone and the paper is set to 1.3 or less, the friction coefficient between the entire paper sheet separator 1 and the paper becomes 1.5 or less,
Remaining trays of paper sheets are prevented. The paper used for friction coefficient measurement is PPC paper (Fuji Xerox Co., Ltd.)
It is.

The hardness (Shore A) of the friction layer 2 is 70 or more. If the hardness is less than 70, the friction coefficient between the friction layer 2 alone and the paper exceeds 1.3, and the tray may remain. If the hardness is too high, the coefficient of friction may decrease and double feed may occur. Therefore, the hardness is preferably 95 or less.

The thickness of the friction layer 2 is 0.2 mm or more and 2.0
mm or less, preferably 0.5 mm or more and 1.5 mm or less. If the thickness is less than the above range, the friction layer 2
May have insufficient durability. Conversely, if the thickness exceeds the above range, the thickness of the foam layer 4 becomes relatively small, and the operation noise may not be sufficiently suppressed.

The first adhesive layer 3 is made of an adhesive, and the friction layer 2 and the foam layer 4 are joined by the first adhesive layer 3. The type of the pressure-sensitive adhesive is not particularly limited as long as the bonding can be achieved. Although the thickness of the first adhesive layer 3 is not particularly limited, it is usually about 1 μm or more and about 20 μm or less. The first adhesive layer 3 may be omitted, and the friction layer 2 and the foam layer 4 may be directly joined.

The foam layer 4 is composed of air bubbles and a base material (a part other than the air bubbles). The base material is mainly composed of a polymer such as a synthetic resin or rubber. The bubbles are formed by the foaming agent foaming in the base material. The blowing agent used may be a pyrolysis type blowing agent or a low boiling type blowing agent. An azo compound or the like can be given as a pyrolysis type foaming agent. Examples of the low-boiling type blowing agent include aliphatic hydrocarbons such as propane, butane and pentane, chlorinated aliphatic hydrocarbons such as methylene chloride and methyl chloride, and inorganic gases such as nitrogen and carbon dioxide. Can be

The cells may be open cells or closed cells. The expansion ratio (the ratio of the density in the absence of air bubbles to the density in the presence of air bubbles) is
It is preferably 3 times or more and 20 times or less. If the expansion ratio is less than the above range, the operation noise may not be sufficiently suppressed. Conversely, if the expansion ratio exceeds the above range, the foam layer 4
May be insufficient in strength.

The thickness of the foam layer 4 is 0.1 mm or more and 1.0
mm or less, preferably 0.3 mm or more and 0.8 mm or less. If the thickness is less than the above range, operation noise may not be sufficiently suppressed. Conversely, if the thickness exceeds the above range, not only does the manufacturing cost of the paper sheet separator 1 increase, but also the thickness of the friction layer 2 becomes relatively small, and the friction coefficient of the paper sheet separator 1 decreases. It can be too large.

The second adhesive layer 5 is made of an adhesive, and the foam layer 4 is joined to the tray substrate by the second adhesive layer 5. The type of the pressure-sensitive adhesive is not particularly limited as long as the bonding can be achieved. Although the thickness of the second adhesive layer 5 is not particularly limited, it is usually about 1 μm or more and 20 μm or less.

The paper sheet separator 1 comprises a foamed double-sided tape having a first adhesive layer 3, a foamed layer 4 and a second adhesive layer 5 formed of a friction layer 2.
It is obtained by being stuck on the back side of Further, in the paper sheet separator 1, after the pressure-sensitive adhesive is applied to the back surface of the friction layer 2 and laminated with the foam layer 4, the pressure-sensitive adhesive is further coated on the back surface of the foam layer 4. Can also be obtained by

FIG. 2 is a schematic cross-sectional view showing an example of the paper feeding mechanism 6 using the paper sheet separator 1 of FIG. The paper feed mechanism 6 includes a paper feed roller 7 and a tray 8. The tray 8 includes a tray substrate 9 and the paper sheet separator 1 attached to the front side of the tray substrate 9 near the paper feed roller 7. A large number of paper sheets 10 are stacked and stored on the tray 8. The portion of the tray 8 closer to the paper feed roller 7 is pushed upward by a spring (not shown) contacting the lower surface thereof, and is pressed toward the paper feed roller 7. The leading end portion 11 of the paper sheet 10 is sandwiched between the paper sheet separator 1 and the paper feed roller 7.

In the paper feeding mechanism 6, the friction coefficient μF between the paper feeding roller 7 and the paper sheet 10, the friction coefficient μR between the tray 8 (that is, the paper sheet separator 1) and the paper sheet 10, and the paper sheet 1
The friction coefficient μP between 0 and 10 is in a relationship represented by the following formula μF>μR> μP (I). When the paper sheet 10 is fed by the paper feed mechanism 6, first, the paper feed roller 7 rotates in the direction indicated by the arrow R. Since the uppermost sheet 10 is in contact with the sheet feeding roller 7 at the leading end portion 11, the sheet is sent out with the rotation of the sheet feeding roller 7 and heads toward the image forming mechanism. At this time, the friction coefficient μ between the paper feed roller 7 and the sheet 10 is
If F is smaller than the friction coefficient μP between the paper sheets 10, 10, the paper sheets 10 will not be sent out or a plurality of paper sheets 10 will be sent out in an overlapping manner, as described above. Since μF is larger than μP, the paper sheets 10 are sent out one by one from the top. Paper 1 on tray 8
For example, when 0 is the remaining two sheets, if the friction coefficient μR between the paper sheet separator 1 and the paper sheet 10 is smaller than the friction coefficient μP between the paper sheets 10 and 10, the remaining paper sheets Although 10 are sent out in an overlapping manner, since μR is larger than μP as described above, only the upper sheet 10 is sent out. When the last sheet 10 on the tray 8 becomes the last sheet, the friction coefficient μF between the sheet feeding roller 7 and the sheet 10 becomes the friction coefficient μR between the sheet separator 1 and the sheet 10. If it is smaller than this, the paper sheet 10 will remain without being sent out, but as described above, since μF is larger than μR, the last paper sheet 10
Is also sent out. In this way, double feeding and remaining trays are prevented.

When the paper sheet 10 is sent out, the paper sheet 1
0 and the paper sheet separator 1 rub against each other, causing vibration. However, since the paper sheet separator 1 includes the foam layer 4 (see FIG. 1), the foam layer 4 absorbs the vibration, and the generation of operation noise is suppressed.

[0026]

EXAMPLES Hereinafter, the effects of the present invention will be clarified by experiments performed based on the examples. However, it should be understood that the present invention should not be construed as being limited based on the description of the examples. It is.

Example 1 Polybutadiene and EPDM
1.2m thick, containing as a main component and crosslinked with peroxide
A rubber plate having a length of m was prepared, and the front side was polished. The Shore A hardness of this rubber plate was 80. The coefficient of friction between the rubber plate alone and the paper was 0.65. On the other hand, a double-sided foam tape (trade name of Nitto Denko Corporation) comprising a foam layer having a thickness of 0.5 mm, a first adhesive layer located on the front side of the foam layer, and a second adhesive layer located on the back side thereof No. 54
1)). Then, the first adhesive layer is brought into contact with the back side of the rubber plate, and the rubber plate and the foam double-sided tape are joined,
A paper sheet isolate of Example 1 was obtained.

Example 2, Example 3, Comparative Example 1, and Comparative Example 2 Example 2 was performed in the same manner as in Example 1 except that the thickness of the foamed layer was varied as shown in Table 1 below. , Example 3, Comparative Example 1 and Comparative Example 2 were obtained.

Comparative Example 3 A paper sheet isolate of Comparative Example 3 was obtained in the same manner as in Example 1 except that a rubber plate containing a plasticizer was used. The Shore A hardness of this rubber plate was 60.

Comparative Example 4 A sheet separator of Comparative Example 4 was obtained in the same manner as in Example 1 except that a double-sided tape having no foam layer was used.

[Comparative Example 5] A comparison was made in the same manner as in Example 1 except that a synthetic leather (Kuraray's trade name "Kurarino") was used instead of the rubber plate, and a double-sided tape having no foam layer was used. The paper sheet isolate of Example 5 was obtained.

[Measurement of Coefficient of Friction] The coefficient of friction of each separated sheet was measured using a friction coefficient tester (trade name “HEI” of Haydon Co., Ltd.).
DON-10 "). Specifically, a test piece obtained by cutting the paper sheet separator into a width of 120 mm and a length of 200 mm was placed on a horizontally placed plate. On the other hand, the common paper was affixed to a weight having a mass of 200 g, a width of 35 mm, and a length of 75 mm such that the F surface (smooth surface) faces outward. Then, the weight was placed on the paper sheet separator, the plate was gradually inclined at a constant speed, and the angle of the plate at the time when the weight started to slide was measured. The friction coefficient was represented by a ratio when the friction coefficient between paper and paper was set to 1.0. The coefficient of friction was measured for each of ten test pieces, and the average and the variation (the value obtained by subtracting the minimum value from the maximum value) were calculated. The results are shown in Table 1 below.

[Evaluation of Operation Sound] Each sheet-separated body was converted to an ink jet printer (trade name “BJC-7” of Canon Inc.).
00J ”) to feed paper. Then, the level of the operation sound generated at this time was heard. A sound that is louder than the sheet-separated body of Comparative Example 5 is indicated by “x”, and an operation sound equivalent to the sheet-separated body of Comparative Example 5 or a sound that is smaller than this is “O”. And This result is shown in Table 1 below.
Is shown in

[0034]

[Table 1]

From the evaluation results in Table 1, the followings were confirmed. First, in the paper sheet separator of Comparative Example 1 in which the thickness of the foam layer is too small, the operation sound is large. Further, in the paper sheet separator of Comparative Example 2 in which the thickness of the foamed layer is too large, the friction coefficient deviates from the appropriate range of 1.0 to 1.5 and becomes large. In addition, even in the paper sheet separator of Comparative Example 3 in which the hardness of the friction layer is too small, 1.0 to 1.5 which is an appropriate range.
The coefficient of friction deviates from that and has increased. Further, in the paper sheet separator of Comparative Example 4 in which the foam layer was not provided, the operation sound was loud. Furthermore, in the paper sheet separator of Comparative Example 5 in which the friction layer is a synthetic leather, the friction coefficient has a large variation. On the other hand, in the paper sheet separator of each embodiment, the friction coefficient is within an appropriate range of 1.0 to 1.5, and the variation of the friction coefficient is small, and the operation noise is not large. From these evaluation results, the superiority of the present invention was proved.

[0036]

As described above, in the paper sheet separator of the present invention, the dispersion of the friction coefficient is small and the operation noise is small. By using the sheet separator in the sheet feeding mechanism, double feed of sheets and remaining trays are prevented, and deterioration of the office environment due to operation noise is suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a paper sheet separator according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view illustrating an example of a paper feed mechanism using the paper sheet separator of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Paper sheet separation body 2 ... Friction layer 3 ... First adhesive layer 4 ... Foam layer 5 ... Second adhesive layer 6 ... Feeding mechanism 7 ... Feeding Roller 8 ... Tray 9 ... Tray board 10 ... Paper 11 ... Front end

Continued on the front page F term (reference) 3F343 FA02 FB02 FB03 FB04 FC01 FC28 GA03 GB01 GC01 GD01 HA14 HB03 HD11 HD18 JD03 JD08 JD37

Claims (2)

[Claims] 1. A foamed layer containing air bubbles, and a friction layer located on the front side of the foamed layer. The foamed layer has a thickness of 0.1 mm or more and 1.0 mm or less. A paper sheet separator that is a main component and has a friction layer having a Shore A hardness of 70 or more. 2. The paper sheet separator according to claim 1, wherein a ratio of a friction coefficient between the friction layer and paper to a friction coefficient between paper and paper is 1.0 or more and 1.3 or less.