Cleaning roll and method for manufacturing cleaning roll

Abstract

To provide a new cleaning roll having high durability and small outer diameter tolerance, and to provide a method for manufacturing the cleaning roll.SOLUTION: A cleaning roll includes a shaft member, and a sheet that includes a foam, is formed in a belt shape, and is wound along an axial direction of the shaft member. The foam includes a first cell, and the first cell has a bent portion that is bent toward the inside of the first cell.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a cleaning roll and a method for manufacturing the cleaning roll. [Background technology]

[0002] Conventionally, cleaning rolls used in devices such as copiers and printers, and in toner cartridges installed in these devices, are known (see, for example, Patent Documents 1 and 2). The cleaning roll of Patent Document 1 includes a shaft member and a foam attached around the shaft member. The foam of the cleaning roll rotates in accordance with the rotation of the charge roll while in contact with the charge roll. In this way, the cleaning roll removes residual toner and foreign particle particles adhering to the surface of the charge roll by contacting the foam with the charge roll.

[0003] There are various methods for manufacturing such cleaning rolls. One example of a method for manufacturing a cleaning roll is a method in which a foam is attached to a shaft member and then the foam is cut to form a cylindrical shape, as in the cleaning roll of Patent Document 1. Another example of a method for manufacturing a cleaning roll is a method in which a sheet containing a foam is wrapped around a shaft member, as in the cleaning roll of Patent Document 2. [Patent Document 1] Patent Publication No. 2021-18292 [Patent Document 2] Patent Publication No. 2011-145410 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for improved durability in devices such as copiers and printers, which has led to a demand for cleaning rolls with higher durability and for the manufacture of such cleaning rolls.

[0005] Furthermore, it is preferable that the foam surface of the cleaning roll be in close contact with the charging roll. For this reason, there is a demand for a cleaning roll with a smaller outer diameter tolerance and a method for manufacturing such a cleaning roll.

[0006] An object of the present disclosure is to provide a novel cleaning roll that is highly durable and has a small outer diameter tolerance, and a method for manufacturing the cleaning roll. [Means for solving the problem]

[0007] The cleaning roll according to the present disclosure includes a shaft member and a band-shaped sheet containing a foam and wound around the shaft member along the axial direction. The foam includes first cells, and the first cells have bent portions that bend inward of the first cells.

[0008] In addition, the method for manufacturing a cleaning roll according to the present disclosure includes a compression step of compressing the foamed foam, a step of forming the foam into a strip-shaped sheet, and a step of wrapping the sheet along the axial direction of a cylindrical shaft member.

[0009] In this cleaning roll, the foam is compressed, resulting in a high foam density. This makes the cleaning roll more durable than conventional cleaning rolls. Furthermore, in this cleaning roll manufacturing method, the compressed foam is wound around the shaft, which can suppress deformation of the foam when the foam is wound around the shaft. Therefore, cleaning rolls manufactured by this cleaning roll manufacturing method have a smaller outer diameter tolerance than conventional cleaning rolls. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a novel cleaning roll that is highly durable and has a small outer diameter tolerance, and a method for manufacturing the cleaning roll. [Brief explanation of the drawings]

[0011] [Figure 1]FIG. 2 is a side view of a cleaning roll according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a front view of a cleaning roll according to an embodiment of the present disclosure. [Figure 3] FIG. 2 is a schematic diagram of a sheet according to an embodiment of the present disclosure before being attached to a shaft member. [Figure 4] A photograph showing the state of the AA cross section of Figure 1. [Figure 5] Photographs showing the change in cross section of a foam when the compression ratio is changed. [Figure 6] FIG. 1 is a schematic diagram showing changes in the first and second cells of a foam when the compression rate is changed. [Figure 7] 1A to 1C are diagrams illustrating a manufacturing procedure according to an embodiment of the present disclosure. [Figure 8] A diagram showing the outer diameter tolerance. DETAILED DESCRIPTION OF THE INVENTION

[0012] <Cleaning Roll Structure> An embodiment of the present disclosure will be described below with reference to the drawings. As shown in FIGS. 1 to 3, a cleaning roll 1 includes a shaft member 2 and a sheet 4. The cleaning roll 1 of this embodiment is attached to a toner cartridge used in a laser printer or a copier. The cleaning roll 1 is attached to the charging roll of such a cartridge with the foam surface of the cleaning roll 1 in contact with the charging roll.

[0013] In recent years, there has been a trend toward longer lifespans for such cartridges. For this reason, the cleaning roll 1 that comes into contact with the charging roller is required to have durability that prevents damage to the foam surface of the cleaning roll 1. Furthermore, in recent years, there has been a trend toward smaller cartridges. For this reason, there is also a demand for smaller cleaning rolls 1.

[0014] The shaft member 2 of this embodiment is a columnar or cylindrical rod made of metal or the like. In this embodiment, the diameter D1 of the shaft member 2 is 3.0 mm to 4.0 mm. The length of the shaft member 2 is generally 226 mm to 350 mm. However, the diameter and length of the shaft member 2 may be set appropriately depending on the device to which the cleaning roll 1 is attached.

[0015] The sheet 4 is formed in a strip shape including a foam 6 and an adhesive layer 8, and is spirally wound around the outer circumferential surface of the shaft member 2 along the axial direction F of the shaft member 2. In this embodiment, the foam 6 is a compressed soft polyurethane foam. Specifically, the foam 6 has an apparent density of 30 kg / m according to JIS K 6401. 3 to 100 kg / m 3 The soft polyurethane foam has an apparent density of 100 kg / m according to JIS K 6401. 3 More preferably, the foam 6 has an apparent density of 70 kg / m or more according to JIS K 6401. 3 The soft polyurethane foam is compressed at a compression rate of 30% or more, and the apparent density according to JIS K 6401 is 140 kg / m 3 The soft polyurethane foam was compressed to the above-mentioned value.

[0016] The thickness of the foam 6 after compression is 1.0 mm to 4.0 mm, and more preferably 3.0 mm or less. The foam 6 of this embodiment is a soft polyurethane foam obtained by compressing a foam 6 having a thickness of 2.0 mm to 2.7 mm before compression to a thickness of 1.0 mm. Therefore, when the diameter D1 of the shaft member 2 is 4.0 mm, the standard diameter D2 of the cleaning roll 1 of this embodiment is 6.0 mm.

[0017] Furthermore, the foam 6 of this embodiment is compressed by hot press molding, in which the foam 6 is pressed while being heated. In this way, by compressing the foam 6 while being heated, the foam 6 is plastically deformed. Therefore, the foam 6 can be prevented from returning to its original shape after being compressed.

[0018] That is, the following invention can also be grasped from the description of this specification.

[0019] A shaft member; a sheet containing a foam, formed in a strip shape, and wound around the shaft member at a predetermined angle along the axial direction; Equipped with The apparent density of the foam is 100 kg / m 3 That's it, cleaning roll.

[0020] Figure 4 is a photograph of the AA cross section of Figure 1 taken with a microscope. As shown in the circled area in Figure 4, the foam 6 formed in this manner includes first cells 10 and second cells 12. The first cells 10 have bent portions 10a that bend toward the inside of the first cells 10. The second cells 12 are adjacent to the first cells 10 and have protrusions 12a that protrude toward the bent portions 10a. Of the multiple cells formed in the foam 6, only some of the first cells 10 and second cells 12 may have the shapes of the first cells 10 and the second cells 12.

[0021] FIG. 5 shows photographs taken with a microscope showing the change in the cross section of foam 6 when the compression ratio of foam 6 is changed. FIG. 5(a) shows foam 6 in an uncompressed state. FIG. 5(b) shows foam 6 in a compressed state at a compression ratio of 50%. FIG. 5(c) shows foam 6 in a compressed state at a compression ratio of 57%. All foams have an apparent density of 70 kg / m according to JIS K 6401. 3 The compressibility is the rate at which the length of the foam 6 in the thickness direction H is reduced. For example, when the length of the foam 6 is reduced from 6.0 mm to 3.0 mm, the compressibility is 50%.

[0022] As shown in Figure 5(a), when the foam 6 is not compressed, multiple rugby ball-shaped cells are formed that are long in the thickness direction H of the sheet 4. Figure 6 is a diagram that schematically shows the state in which such rugby ball-shaped cells shrink. In the foam 6, adjacent first cells 10 and second cells 12 are arranged so as to overlap in the thickness direction H. That is, when the foam 6 is wrapped around the shaft member 2, the first cells 10 and second cells 12 are arranged so as to overlap in a direction perpendicular to the axial direction F in a cross section perpendicular to the axial direction F.

[0023] As shown in Figure 6(b), when the foam 6 is compressed, the first cells 10 are crushed toward the second cells 12, and the cell walls between the first cells 10 and the second cells 12 are pressed toward the inside of the first cells 10. This causes the cell walls to deform toward the inside of the first cells 10, forming bent portions 10a. Therefore, whether or not a bent portion 10a exists can be determined by whether or not the cell walls between the first cells 10 and the second cells 12 are pushing toward the inside of the first cells 10. When this state is viewed in the photograph of Figure 5(b), it appears as the circled portion.

[0024] At this time, the second cells 12 also shrink in the thickness direction H. As a result, the second cells 12 form protrusions 12a that protrude toward the first cells 10. Therefore, the criterion for determining the protrusions 12a is whether or not the width X of the second cells 12 decreases toward the bent portions 10a of the first cells 10, as shown in FIG. 6(b).

[0025] As shown in FIG. 6(c), further compression causes the first cell 10 and the second cell 12 to shrink in the thickness direction H. Furthermore, the width X of the second cell 12 in the thickness direction H becomes smaller. Note that either or both of the first cell 10 and the second cell 12 may be completely crushed. In particular, the crushed state of the second cell 12 is seen as the circled area in the photograph of FIG. 5(c).

[0026] 3, the adhesive layer 8 is a layer provided between the foam 6 and the shaft member 2. The adhesive layer 8 may be made of any material, such as an adhesive agent or adhesive tape, as long as it is capable of adhering the foam 6 to the shaft member 2. <Manufacturing Method of Cleaning Roll> Next, a manufacturing procedure (method) for the cleaning roll 1 of this embodiment will be described with reference to FIG.

[0027] As shown in Figure 7(a), first, the apparent density according to JIS K 6401 is 30 kg / m 3 to 100 kg / m 3 In this embodiment, a polyurethane foam block is prepared by mixing an A liquid mainly containing an isocyanate and a B liquid mainly containing a polyol on a belt conveyor or in a foaming mold, followed by foaming and curing.

[0028] As shown in FIG. 7(b), the block is then sliced to a predetermined thickness to form the foam 6 into a sheet. The slice thickness may be changed as appropriate depending on the compression rate and the thickness of the foam 6 after compression. For example, when a sheet 4 having a thickness of 3.0 mm is produced at a compression rate of 50%, the slice thickness may be set to 6.0 mm.

[0029] As shown in FIG. 7(c), the sheet-like foam 6 is then placed in a press 14. The press 14 can compress the foam 6 while heating it. The press 14 compresses the foam 6 at a compression rate of 30% or more. The compression rate may be set appropriately between 30% and 80%, depending on the target apparent density and thickness of the foam 6 after compression.

[0030] After the above compression step is completed, an adhesive layer 8 is formed on the foam 6. In this embodiment, an adhesive sheet is attached to the foam 6. Thereafter, as shown in FIG. 7(d), the foam is cut to a predetermined width and length to form a strip-shaped sheet 4. In this embodiment, the sheet 4 is cut to a width of 7.0 mm and a length of 400 mm. However, the width and length of the sheet 4 may be changed as appropriate depending on the length of the shaft member 2, the proportion of the outer peripheral surface of the shaft member 2 that the sheet 4 covers, etc.

[0031] As shown in FIG. 7(e), the sheet 4 is then wrapped around the shaft member 2 at a predetermined angle α along the axial direction. The predetermined angle α varies depending on factors such as the proportion of the outer peripheral surface of the shaft member 2 that the sheet 4 covers. In this embodiment, the sheet 4 is wrapped around the shaft member 2 so that the sheet 4 covers 90% or more of the outer peripheral surface of the shaft member 2. In other words, the sheet 4 is wrapped around the outer peripheral surface of the shaft member 2 without any gaps. In this case, the predetermined angle α is preferably 45 to 60 degrees.

[0032] In the process of winding the sheet 4 around the shaft member 2, the shaft member 2 is rotated at a predetermined rotational speed while the end 4a of the sheet 4 is moved along the axial direction F in the winding direction R at a predetermined moving speed. In this way, the shaft member 2 winds up the sheet 4. The relationship between the predetermined rotational speed and the predetermined moving speed varies depending on the diameter of the shaft member 2, the material of the sheet 4, etc.

[0033] Such a cleaning roll 1 has high durability because the foam 6 is compressed, increasing the apparent density according to JIS K 6401. For example, according to the findings of the inventors, when a polyurethane foam is hot-pressed, the tensile strength, elongation, and tear strength according to JIS K 6401 of the foam 6 are improved compared to when the foam 6 is not compressed. Furthermore, the improvement in durability is significant when the compression ratio is 70% or more.

[0034] Furthermore, the cleaning roll 1 reduces the thickness of the sheet 4 by compressing the foam 6. This allows the diameter D2 (see FIG. 2) of the cleaning roll 1 to be smaller than when the foam 6 is wound around the shaft member 2 without being compressed. This makes the cleaning roll 1 smaller and more durable than conventional cleaning rolls.

[0035] Furthermore, conventional cleaning rolls, in which a foam-containing sheet 4 is wound around a shaft member, have a low density and a large thickness, making the center of the sheet prone to deformation and denting. However, in the cleaning roll 1 of the present disclosure, the foam 6 is compressed, increasing its density and reducing its thickness. This reduces deformation of the center of the sheet 4 when the sheet 4 is wound around the shaft member 2. As a result, the cleaning roll 1 can have a small outer diameter tolerance. Here, the outer diameter tolerance refers to a value related to the variation in the diameter (outer diameter) D2 of the cleaning roll 1. Specifically, as shown in FIG. 8, variation in the distance T from the deepest position B of the recess 6a formed on the surface of the foam 6 to the shaft surface causes variation in the diameter D2 of the cleaning roll 1. This variation can be obtained by measuring the diameter D2 of the cleaning roll 1 while rotating the cleaning roll 1. The outer diameter tolerance is the value of the diameter D2 plus or minus 3σ standard deviation when the diameter D2 is measured at multiple points on the same cleaning roll 1 or on different cleaning rolls 1 while the cleaning roll 1 is rotated.

[0036] For example, as shown in Table 1, the inventors have found that the apparent density according to JIS K 6401 is 70 kg / m 3 Three polyurethane foams with thicknesses of 2.0 mm (Example 1), 2.35 mm (Example 2), and 2.7 mm (Example 3) were compressed by hot press molding to 1.0 mm and wound around a 4.0 mm shaft member 2 to produce cleaning rolls 1. Five cleaning rolls 1 were produced for each of Examples 1 to 3. The inventors obtained the standard deviation σ of the diameter D2 of each of Examples 1 to 3. As a result, the standard deviation σ of the diameter D2 of the five cleaning rolls 1 of each Example was 0.032 mm for Example 1, 0.036 mm for Example 2, and 0.041 mm for Example 3. Meanwhile, as shown in the comparative example in Table 1, the inventors obtained the standard deviation σ of the diameter D2 of each of the five cleaning rolls 1 of each Example, which was 0.032 mm for Example 1, 0.036 mm for Example 2, and 0.041 mm for Example 3. 3A cleaning roll was produced by winding a 2.35 mm thick polyurethane foam around a 4.0 mm shaft member 2. Five cleaning rolls for the comparative example were also produced, similar to the cleaning rolls 1 of each example. As a result, the standard deviation σ of the diameter D2 of the cleaning roll of the comparative example was 0.111 mm. Therefore, the cleaning rolls 1 of all examples 1 to 3 had a smaller standard deviation σ and smaller variations than the comparative example. In this way, the inventors discovered that by compressing the foam 6, cleaning rolls 1 with a small outer diameter tolerance could be produced.

[0037] [Table 1]

[0038] Furthermore, in a cleaning roll such as that of Patent Document 1, in which a foam is attached to a shaft member and then polished to form the foam shape, if the foam is made thin (for example, 3.0 mm or less), the shaft member becomes visible through the foam, resulting in a problem in appearance quality. However, according to the cleaning roll 1 of the present disclosure and the manufacturing method for the cleaning roll 1 of the present disclosure, the foam 6 is wound around the shaft member 2 in a compressed state. This increases the density of the foam 6, and the shaft member 2 does not become visible through the foam.

[0039] As described above, a novel cleaning roll 1 having high durability and small outer diameter tolerance, and a method for manufacturing the cleaning roll 1 can be provided. <Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention.

[0040] For example, in the above embodiment, the foam 6 is described as being made of a soft polyurethane foam, but the present disclosure is not limited to this. The foam 6 may be made of a material other than soft polyurethane as long as it is made of compressed elastic foam.

[0041] In this embodiment, the foam 6 is compressed and then formed into the strip-shaped sheet 4, but the present disclosure is not limited to this. The compression step may be performed after the strip-shaped sheet 4 is formed. [Explanation of symbols]

[0042] 1: cleaning roll, 2: shaft member 4: Sheet, 4a: Edge, 6: Foam, 6a: Recess 8: adhesive layer, 10: first cell, 10a: bending portion 12: second cell, 12a: protrusion, 14: press F: Axial direction H: Thickness direction R: Direction α: Angle

Claims

1. A shaft member; a sheet containing polyurethane foam, formed in a strip shape, and wound around the shaft member in the axial direction; Equipped with the foam includes first cells; the first cell has a bent portion bent toward the inside of the first cell, The sheet is wound around the outer peripheral surface of the shaft member so that no gap is formed between adjacent sheets in the width direction of the sheet.

2. the foam has second cells adjacent to the first cells; the second cell includes a protrusion protruding toward the bent portion, The cleaning roll for a charging roll according to claim 1 .

3. In the foam, in a cross section perpendicular to the axial direction of the shaft member, the bent portions of the first cells and the protruding portions of the second cells are arranged to overlap in a direction perpendicular to the axial direction. The cleaning roll for a charging roll according to claim 2 .

4. The apparent density of the foam is 100 kg / m ３ That's all. The cleaning roll for a charging roll according to any one of claims 1 to 3.

5. a compressing step of compressing the foam-molded polyurethane foam; forming the foam into a strip-shaped sheet; a step of winding the sheet along the axial direction of a shaft member; The method for manufacturing a cleaning roll for a charging roll according to claim 1 , comprising:

6. In the compressing step, the foam is compressed while being heated. The method for producing a cleaning roll for a charging roll according to claim 5 .

7. Apparent density 50 kg / m ３ to 100 kg / m ３ providing a foam comprising: In the compressing step, the foam is compressed at a compression rate of 30% or more. The method for producing a cleaning roll for a charging roll according to claim 5 or 6.

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