Cut pile sealing material, developing apparatus having the cut pile sealing material, and image forming apparatus equipped with the developing apparatus.

Abstract

To provide a cut pile sealing material with excellent sealing properties for two-component developers, and a developing apparatus and an image forming apparatus equipped therewith. [Solution] A cut pile sealing material for sealing a two-component developer, wherein the cut pile sealing material has at least two types of cut piles, each of which forms a stripe on the surface of the cut pile sealing material, and the at least two types of cut piles include a first cut pile having a charge characteristic of negative frictional charging with iron, and a second cut pile having a charge characteristic of positive frictional charging with iron, as well as a developing apparatus and an image forming apparatus equipped therewith.

Description

Technical Field

[0005] , ,

[0001] The present invention relates to a cut pile sealing material, a developing device having the cut pile sealing material, and an image forming device including the developing device.

Background Art

[0002] The electrophotographic method used in image forming devices such as copiers, laser beam printers, facsimiles, and multifunction machines thereof is roughly classified into a dry developing method and a wet developing method. In the dry developing method, toner particles are attached to a charged photoreceptor to form an image, and printing is performed by transferring the image to a printing medium such as paper.

[0003] As the dry developing method, a two-component developing method and a one-component developing method are known. In the two-component developing method, a two-component developer containing non-magnetic toner particles and magnetic carrier particles is used. In the one-component developing method, the magnetic carrier particles are not used, and a one-component developer containing charged toner particles is used.

[0004] As a sealing material for the developer used in the dry developing method, a sealing material having a cut pile fabric or a cut pile knitted fabric (hereinafter sometimes referred to as "cut pile woven / knitted fabric") (hereinafter sometimes referred to as "cut pile sealing material") is known. Patent Document 1 discloses a strip-shaped first sealing region composed only of a plurality of first fiber bundles including first fibers having a charging property that repels the developer, and a strip-shaped second sealing region composed only of a plurality of second fiber bundles including second fibers having a charging property that attracts the developer, which are arranged in a stripe shape. Patent Document 1 describes that by applying the cut pile sealing material disclosed in Patent Document 1 to a developing unit using a one-component developer, the toner sealing property is improved.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] The present inventors applied the cut pile sealing material disclosed in Patent Document 1 to an image forming apparatus employing a two-component development method as a sealing material for a two-component developer. As a result, contrary to initial expectations, it was found that the cut pile sealing material disclosed in Patent Document 1 may not provide sufficient sealing performance for the two-component developer.

[0007] The present invention aims to provide a cut pile sealing material that exhibits excellent sealing properties for two-component developers. Furthermore, the present invention aims to provide a developing apparatus employing a two-component developing method and equipped with the above-mentioned cut pile sealing material. Moreover, the present invention aims to provide an image forming apparatus employing a two-component developing method and equipped with the above-mentioned developing apparatus. [Means for solving the problem]

[0008] The present invention relates to a cut pile sealing material for sealing a two-component developer, wherein the cut pile sealing material has at least two types of cut piles, each of which forms a stripe on the surface of the cut pile sealing material, and the at least two types of cut piles include a first cut pile having a charge characteristic of negative frictional charging with iron, and a second cut pile having a charge characteristic of positive frictional charging with iron. The present invention also relates to a developing apparatus employing a two-component developing method, which has the above-described cut pile sealing material. Furthermore, the present invention relates to an image forming apparatus employing a two-component developing method, which is equipped with the above-described developing apparatus. [Effects of the Invention]

[0009] The present invention provides a cut pile sealing material that exhibits excellent sealing properties for two-component developers. Furthermore, the present invention provides a developing apparatus and an image forming apparatus employing a two-component developing method in which leakage of the two-component developer is suppressed. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic diagram showing an image forming apparatus according to an embodiment of the present invention. [Figure 2] Figure 2 is a conceptual diagram of a horizontal cross-section of a developing apparatus according to an embodiment of the present invention. [Figure 3] Figure 3 is a conceptual diagram of a front cross-section of a developing apparatus according to an embodiment of the present invention. [Figure 4] Figure 4 is a conceptual diagram of a side cross-section of a developing apparatus according to an embodiment of the present invention. [Figure 5] Figure 5 is a schematic diagram showing a cut pile sealing material according to an embodiment of the present invention. [Figure 6] Figure 6 is a conceptual diagram of the surface of a cut pile knitted fabric. [Figure 7] Figure 7 is a conceptual diagram of the side view of a cut pile knitted fabric, viewed from the direction of the arrow in Figure 6. [Figure 8] Figure 8 is an explanatory diagram illustrating the evaluation method for the electrostatic properties of cut pile. [Modes for carrying out the invention]

[0011] The present invention will now be described in detail based on preferred embodiments, with appropriate reference to the accompanying drawings. However, the present invention is not limited to these examples, and is intended to include all modifications within the meaning and scope of the claims, as indicated by the claims.

[0012] (1) One embodiment of the present invention is a cut pile sealing material for sealing a two-component developer, The above cut pile sealing material has at least two types of cut piles, The above at least two types of cut pile form stripes that each form a line on the surface of the cut pile sealing material. The above at least two types of cut pile include a first cut pile having an electrostatic charging property where the frictional electrostatic charging with iron is negative, and a second cut pile having an electrostatic charging property where the frictional electrostatic charging with iron is positive.

[0013] The cut pile sealing material in (1) above has excellent sealing properties for a two-component developer.

[0014] (2) In the cut pile sealing material described in (1) above, the first cut pile is a cut pile composed of at least one fiber material selected from polytetrafluoroethylene, acrylic, and berryma, and the second cut pile is a cut pile composed of at least one fiber material selected from rayon, nylon, and cotton.

[0015] (3) In the cut pile sealing material described in (1) or (2) above, the first cut pile is a cut pile composed of acrylic fibers, and the second cut pile is a cut pile composed of rayon fibers.

[0016] (4) In the cut pile sealing material described in any one of (1) to (3) above, the cut pile sealing material has two types of cut pile, namely the first cut pile and the second cut pile.

[0017] (5) In the cut pile sealing material described in any one of (1) to (4) above, the electrostatic charging property is evaluated based on the difference in the surface potential of the surface of the cut pile sealing material having only one type of cut pile as the test specimen before and after friction with iron.

[0018] ​(6) In the cut pile sealing material described in any of (1) to (5) above, the electrostatic properties described above shall be evaluated in accordance with surface potential measurement using a non-contact electrostatic potentiometer as described in Japanese Industrial Standard JIS C 61340-2-2:2013 3.1c).

[0019] The cut pile sealing material described in any of (2) to (6) above has superior sealing properties against two-component developers.

[0020] (7) Another embodiment of the present invention is a developing apparatus employing a two-component developing method, having a cut pile seal material as described in any of (1) to (6) above.

[0021] (8) The developing apparatus described in (7) above is A housing for storing the above two-component developer, A stirring screw for stirring the two-component developer housed in the above-mentioned housing, Includes, The above stirring screw has a rotating shaft that is rotatably supported in the above housing, The above housing has an insertion hole into which the above rotating shaft is inserted, The cut pile sealing material described above is placed in the gap between the rotating shaft and the insertion hole described above.

[0022] The developing apparatus described in (7) or (8) above suppresses leakage of the two-component developer.

[0023] (9) Another embodiment of the present invention is an image forming apparatus employing a two-component developing method, comprising the developing apparatus described in (7) or (8) above.

[0024] The image forming apparatus described in (9) above suppresses leakage of the two-component developer.

[0025] [Basic configuration of an image forming apparatus] Figure 1 is a schematic diagram showing an image forming apparatus 1 according to an embodiment of the present invention. The image forming apparatus 1 is an image forming apparatus employing a two-component development method. The image forming apparatus according to the present invention may be any image forming apparatus employing a known two-component development method, and is not particularly limited. The image forming apparatus 1 includes a paper storage unit 10, a paper feed roller 20, an image forming unit 30, a toner storage unit 40, a fuser unit 50, a paper discharge roller 60, and a paper discharge unit 70.

[0026] The paper stored in the paper storage unit 10 is transported to the image forming unit 30 via the paper feed roller 20. In the image forming unit 30, a toner image formed based on image data transmitted from a device such as a personal computer (not shown) is transferred to the paper. Non-magnetic toner particles (hereinafter sometimes referred to as "toner") are supplied to the image forming unit 30 from the toner storage unit 40. The paper on which the toner image has been transferred is transported to the fuser unit 50, where it is heated and pressurized. This fixes the toner image to the paper. The paper that has passed through the fuser unit 50 is transported to the paper discharge unit 70 via the paper discharge roller 60.

[0027] The image forming unit 30 includes a photoreceptor drum 31, a charging device 32, an exposure unit 33, a developing device 34, a paper transport path 35, a registration roller 36, a transfer roller 37, and a cleaning device 38. The photoreceptor drum 31 of the image forming apparatus 1 has a photosensitive layer laminated on the outer surface of an aluminum drum. The charging device 32 is a device for uniformly charging the outer surface of the photoreceptor drum 31. In the image forming apparatus 1, a corona discharge device is used as the charging device 32. The exposure unit 33 irradiates the photoreceptor drum 31 with a light beam based on the above-mentioned image data to form an electrostatic latent image on the outer surface of the photoreceptor drum 31. The developing device 34 deposits toner onto the electrostatic latent image on the photoreceptor drum 31 to form a toner image. Paper transported to the image forming unit 30 is guided through the paper transport path 35 and the registration roller 36 to the transfer nip area between the photoreceptor drum 31 and the transfer roller 37. The toner image formed on the photoreceptor drum 31 is transferred to the paper as it passes through the transfer nip area.

[0028] [Basic configuration of a developing machine] Figure 2 is a conceptual horizontal cross-sectional view of a developing apparatus 34 according to an embodiment of the present invention. Figure 3 is a conceptual front cross-sectional view of a developing apparatus 34 according to an embodiment of the present invention. Figure 4 is a conceptual side cross-sectional view of a developing apparatus 34 according to an embodiment of the present invention. The developing apparatus 34 comprises a housing 340, a first stirring screw 341, a second stirring screw 342, a developing roller 343, a regulating blade 344, a toner regulating guide 345, a magnetic sealing material 346, a first cut pile sealing material 347, a second cut pile sealing material 348, and a third cut pile sealing material 349.

[0029] The housing 340 houses a two-component developer including magnetic carrier particles (hereinafter sometimes referred to as "carriers") and toner supplied from the toner storage section 40. The toner stored in the toner storage section 40 is supplied into the housing 340 through the toner supply port TSP provided in the housing 340. The inside of the housing 340 is divided into a first storage chamber FHR and a second storage chamber SHR by a partition wall 340a formed integrally with the housing 340. The first storage chamber FHR is equipped with a first stirring screw 341, and the second storage chamber SHR is equipped with a second stirring screw 342.

[0030] The first stirring screw 341 has a configuration in which helical blades 341b are provided around a rotating shaft 341a. Both ends of the rotating shaft 341a are rotatably inserted into the first insertion hole FIH provided in the housing 340. A first cut pile sealing material 347 is fitted into the first insertion hole FIH. The first cut pile sealing material 347 fitted into the first insertion hole FIH is configured such that the outer circumference of the rotating shaft 341a inserted into the first insertion hole FIH and the cut pile of the first cut pile sealing material 347 come into contact. This suppresses leakage of the two-component developer from the gap between the rotating shaft 341a and the first insertion hole FIH.

[0031] The second stirring screw 342, like the first stirring screw 341, has a configuration in which helical blades 342b are provided around the rotating shaft 342a. Both ends of the rotating shaft 342a are rotatably inserted into the second insertion hole SIH provided in the housing 340. A second cut pile seal material 348 is fitted into the second insertion hole SIH. The second cut pile seal material 348 fitted into the second insertion hole SIH is configured such that the outer circumference of the rotating shaft 342a inserted into the second insertion hole SIH and the cut pile of the second cut pile seal material 348 come into contact. This suppresses leakage of the two-component developer from the gap between the rotating shaft 342a and the second insertion hole SIH.

[0032] As shown in Figure 2, the first stirring screw 341 and the second stirring screw 342 are rotatably supported in the housing 340 in a parallel manner to each other. There are no partition walls 340a at both ends in the longitudinal direction of the housing 340, which is the axial direction of the first stirring screw 341 and the second stirring screw 342. Therefore, the two-component developer can be moved between the first storage chamber FHR and the second storage chamber SHR. As a result, the first stirring screw 341 transports the two-component developer in the first storage chamber FHR in the direction of arrow P while stirring, and moves it to the second storage chamber SHR. The second stirring screw 342 transports the two-component developer that has been transported to the second storage chamber SHR in the direction of arrow Q while stirring, and supplies it to the developing roller 343, and also moves it to the first storage chamber FHR. This allows a two-component developer in which the carrier and toner are properly mixed to be supplied to the developing roller 343.

[0033] As described above, the two-component developer in the first containment chamber FHR is transported in the direction of arrow P by the first stirring screw 341. Therefore, the wall surface of the housing 340 located in the direction of arrow P experiences higher pressure from the two-component developer than the wall surface of the housing 340 located in the opposite direction of arrow P. As a result, the two-component developer is prone to leaking from the gap between the rotating shaft 341a and the first insertion hole FIH, which is located in the direction of arrow P. Therefore, by placing the first cut pile seal material 347 in the gap between the rotating shaft 341a and the first insertion hole FIH, which is located in the direction of arrow P, leakage of the two-component developer from the developing device 34 can be effectively suppressed.

[0034] As described above, the two-component developer in the second containment chamber SHR is transported in the direction of arrow Q by the second stirring screw 342. Therefore, the wall surface of the housing 340 located in the direction of arrow Q is subjected to higher pressure from the two-component developer than the wall surface of the housing 340 located in the opposite direction of arrow Q. As a result, the two-component developer is prone to leaking from the gap between the rotating shaft 342a and the second insertion hole SIH, which is located in the direction of arrow Q. Therefore, by placing the second cut pile seal material 348 in the gap between the rotating shaft 342a and the second insertion hole SIH, which is located in the direction of arrow Q, leakage of the two-component developer from the developing device 34 can be effectively suppressed.

[0035] The developing roller 343 has rotating shafts 343a at both ends. The rotating shafts 343a are rotatably inserted into a third insertion hole TIH provided in the housing 340. A third cut pile sealing material 349 is fitted into the third insertion hole TIH. The third cut pile sealing material 349 fitted into the third insertion hole TIH is configured such that the outer circumference of the rotating shaft 343a inserted into the third insertion hole TIH contacts the cut pile of the third cut pile sealing material 349. This suppresses leakage of the two-component developer from the gap between the rotating shaft 343a and the third insertion hole TIH. In addition, magnetic sealing materials 346 are arranged at both ends of the outer surface of the developing roller 343 to suppress leakage of the two-component developer from the gap between the housing 340 and the developing roller 343.

[0036] The developing roller 343 has a magnet body 343b inside, which is made up of a permanent magnet having multiple magnetic poles. The magnetic force of the magnet body 343b causes the two-component developer to adhere to the outer surface of the developing roller 343, thereby forming a magnetic brush. The developing roller 343 with the magnetic brush formed rotates in accordance with the rotation of the photoreceptor drum 31 on which an electrostatic latent image has been formed. As a result, the toner of the two-component developer detaches from the carrier and adheres to the electrostatic latent image on the photoreceptor drum 31. Note that the developing roller 343 is configured so that the magnet body 343b does not rotate during its rotation, but only its outer surface rotates.

[0037] The regulating blade 344 is positioned at a predetermined distance from the developing roller 343 to regulate the thickness of the toner layer adhering to the photoreceptor drum 31. A toner regulating guide 345 is positioned upstream of the regulating blade 344 in the direction of rotation of the developing roller 343. The toner regulating guide 345 promotes toner exchange upstream of the regulating blade 344, thereby suppressing toner accumulation.

[0038] [Basic composition of cut pile sealing material] Figure 5 is a schematic diagram showing a cut pile sealing material according to an embodiment of the present invention. Figure 5 shows a first cut pile sealing material 347 as an example of a cut pile sealing material according to an embodiment of the present invention. The first cut pile sealing material 347, the second cut pile sealing material 348, and the third cut pile sealing material 349 have similar basic configurations. Therefore, the descriptions of the second cut pile sealing material 348 and the third cut pile sealing material 349 are omitted.

[0039] The first cut pile seal material 347 comprises a cut pile woven or knitted fabric 100 and a retaining member 200. The back surface of the cut pile woven or knitted fabric 100 is fixed to the retaining member 200 with double-sided tape or adhesive. The retaining member 200 has a plate-like structure that bends into an annular shape and has a joint 200a. The retaining member 120 is made of an elastic body. The elastic body can be made of a known material that is used as a retaining member for the cut pile seal material. Examples of the elastic body include shape-retaining sheets and stainless steel strips for springs.

[0040] As described above, the first cut pile seal material 347 has a retaining member 200 made of an elastic material. Therefore, by applying an external force to bring the joint 200a of the retaining member 200 together, the diameter of the ring formed by the retaining member 200 can be reduced. Also, when the above external force is released, the retaining member 200 tries to return to its original state. Therefore, the diameter of the ring formed by the retaining member 200 increases.

[0041] The diameter of the first insertion hole FIH is set to be larger than the diameter of the ring formed by the retaining member 200 when the joint 200a of the retaining member 200 is aligned. Therefore, when the first cut pile seal material 347 is fitted into the first insertion hole FIH, the first cut pile seal material 347 is fitted into the first insertion hole FIH with an external force applied to align the joint 200a of the retaining member 200. Once fitted into the first insertion hole FIH, the first cut pile seal material 347 expands in diameter due to springback when the external force is released and is attached to the first insertion hole FIH. This increases the adhesion of the first cut pile seal material 347 to the first insertion hole FIH.

[0042] [Basic structure of cut pile knitted fabrics] Figure 6 is a conceptual diagram of the surface of the cut pile woven fabric 100. The surface of the cut pile woven fabric 100 is the surface on which the first cut pile 110 and the second cut pile 120 are provided. Figure 7 is a conceptual diagram of the side view of the cut pile woven fabric 100 as seen from the direction of the arrow in Figure 6. The cut pile woven fabric 100 has the first cut pile 110, the second cut pile 120, and the fabric portion 130.

[0043] The cut pile woven fabric 100 is produced by shearing a pile woven fabric that includes a first pile yarn which forms the basis of the first cut pile 110, and a second pile yarn which forms the basis of the second cut pile 120. The first cut pile 110 and the second cut pile 120 are formed by the shearing of the pile woven fabric, which causes the twist of each fiber constituting the pile yarn to unravel and separate each fiber. The fabric portion 130 is composed of a base fabric made of ground yarn. The ground yarn can be any known yarn used in cut pile woven fabrics and is not particularly limited.

[0044] In the pile woven fabric described above, the first pile yarn and the second pile yarn are woven in parallel and linear directions. Therefore, in the cut pile woven fabric 100 after shearing, as shown in Figure 6, the first cut pile 110 and the second cut pile 120 each form stripes on the surface of the cut pile woven fabric 100. That is, on the surface of the cut pile woven fabric 100, the first cut pile 110 and the second cut pile 120 each form linear lines. Furthermore, on the surface of the cut pile woven fabric 100, the lines of the first cut pile 110 and the lines of the second cut pile 120 form stripes that are arranged in parallel in a striped pattern.

[0045] Figure 6 is a conceptual diagram showing that the lines of the first cut pile 110 are formed by shearing one first pile yarn, and the lines of the second cut pile 120 are formed by shearing one second pile yarn. However, the lines of the cut pile are not limited to those formed by shearing one pile yarn. For example, the cut pile woven fabric 100 may be formed by shearing the lines of the first cut pile 110 with two adjacent first pile yarns, and the lines of the second cut pile 120 with three adjacent second pile yarns.

[0046] The first cut pile 110 has a charge characteristic in which it becomes negatively charged when it comes into contact with iron. The second cut pile 120 has a charge characteristic in which it becomes positively charged when it comes into contact with iron. Therefore, on the surface of the first cut pile sealing material 347, a striped configuration is formed in which lines of the first cut pile 110, which has a charge characteristic in which it becomes negatively charged when it comes into contact with iron, and lines of the second cut pile 120, which has a charge characteristic in which it becomes positively charged when it comes into contact with iron. As a result, the first cut pile sealing material 347, which comprises the cut pile woven or knitted fabric 100, has excellent sealing properties against two-component developers.

[0047] The electrostatic properties of the first cut pile 110 are evaluated based on the difference in surface potential between the surface of the cut pile sealing material (hereinafter sometimes referred to as the "first test specimen"), which comprises a cut pile woven or knitted fabric having only the first cut pile 110 as the test specimen, and iron, before and after friction. The electrostatic properties of the second cut pile 120 are evaluated based on the difference in surface potential between the surface of the second test specimen (hereinafter sometimes referred to as the "second test specimen"), which comprises a cut pile woven or knitted fabric having only the second cut pile 120 as the test specimen, and iron, before and after friction. Preferably, the first and second test specimens are cut pile sealing materials having the same configuration as the first cut pile sealing material 347, except that they have only the first cut pile 110 or the second cut pile 120.

[0048] The electrostatic properties of the first and second test specimens can be evaluated using known methods. In this invention, it is preferable that the electrostatic properties be evaluated in accordance with surface potential measurement using a non-contact electrostatic meter as described in Japanese Industrial Standard JIS C 61340-2-2:2013 3.1c).

[0049] The first cut pile 110 may be a cut pile composed of at least one fiber material selected from polytetrafluoroethylene (hereinafter sometimes referred to as "PTFE"), acrylic, and bellma. The second cut pile 120 may be a cut pile composed of at least one fiber material selected from rayon, nylon, and cotton. The first cut pile seal material 347 having the first cut pile 110 and the second cut pile 120 composed of the above fiber materials has superior sealing properties with respect to two-component developers. In particular, the first cut pile seal material 347 having the first cut pile 110 composed of acrylic fibers and the second cut pile 120 composed of rayon fibers has even superior sealing properties with respect to two-component developers.

[0050] [Other embodiments] The first cut pile sealing material 347 has a stripe formed by two types of cut piles, the first cut pile 110 and the second cut pile 120, but the present invention is not limited to this. For example, the cut pile sealing material of the present invention can also have a stripe formed by three or more types of cut piles. For example, a cut pile sealing material having three types of cut piles can be mentioned, consisting of a first cut pile made of acrylic fiber, a second cut pile made of rayon fiber, and a third cut pile made of bellflower fiber. In this case, the three types of cut piles should form a stripe on the surface of the cut pile sealing material such that the line of the second cut pile is adjacent to the line of the first cut pile and the line of the third cut pile. As a result, a stripe configuration is formed on the surface of the cut pile sealing material in which lines of cut piles having a negative charge characteristic with iron and lines of cut piles having a positive charge characteristic with iron are adjacent. Therefore, the cut pile sealing material having the three types of cut piles has excellent sealing properties against two-component developers. [Examples]

[0051] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0052] [Manufacturing of cut pile fabric] Using the yarns shown in Table 1, pile fabrics were woven on a jacquard loom. The pile yarns of the woven pile fabrics were cut approximately in the middle using a cutter attached to the loom. The cut pile fabrics after the pile yarns were cut were sheared on a shearing machine to produce cut pile fabrics 1-6 with a cut pile length of 2.8 mm.

[0053] [Table 1]

[0054] In this embodiment, PTFE refers to a PTFE yarn manufactured by Toray Industries, Inc., with a fiber material of PTFE, a thickness of 440 decitex, and a fiber count of 60 in the yarn cross-section. Acrylic refers to an acrylic yarn manufactured by Toray Industries, Inc., with a fiber material of acrylic, a thickness of 393.7 decitex, and a fiber count of 236 in the yarn cross-section. Berryma refers to a Berryma yarn manufactured by KB Seiren Co., Ltd., with a fiber material of Berryma, a thickness of 84 decitex before splitting, and a fiber count of 28 in the yarn cross-section. Rayon refers to a rayon yarn manufactured by ADITYA BIRLA GROUP PT. ELEGANT TEXTILE INDUSTRY, Inc., with a fiber material of rayon, a thickness of 500 decitex, and a fiber count of 132 in the yarn cross-section. Warp polyester refers to a polyester yarn manufactured by KB Seiren Co., Ltd., with a fiber material of polyester, a thickness of 168 decitex, and a fiber count of 72 in the yarn cross-section. The weft polyester refers to a polyester yarn manufactured by Toray Industries, Inc., with a fiber material of polyester, a thickness of 33 decitex, and a cross-sectional fiber count of 12.

[0055] Cut pile fabrics 1-4 have only a first cut pile formed by shearing the first pile yarn.

[0056] Cut pile fabric 5 and cut pile fabric 6 have a first cut pile formed by shearing the first pile yarn and a second cut pile formed by shearing the second pile yarn. The surface of the cut pile fabric is composed of stripes formed by a first line made of the first cut pile and a second line made of the second cut pile.

[0057] [Preparation of cut pile sealing material] An acrylic emulsion (CM4025: manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) was applied as a coating agent to the back surface of each of the cut pile fabrics 1 to 6 that had been prepared. After the coating agent had dried, a foam material (ESH: manufactured by Inoac Corporation), which serves as a retaining material, was attached to each of the cut pile fabrics 1 to 6 using double-sided tape to prepare the cut pile sealing materials 1 to 6 shown in Table 2.

[0058] [Table 2]

[0059] [Evaluation of the electrostatic properties of cut pile] Figure 8 is an explanatory diagram illustrating the evaluation method for the electrostatic properties of cut piles. In this example, using cut pile sealing materials 1 to 4, the electrostatic properties of cut piles made of PTFE, acrylic, bellima, and rayon were evaluated in triboelectric charging with iron.

[0060] As shown in Figure 8(a), the back surface of the cut pile seal material, which was to be used as a test specimen, was fixed to a fixing stand with double-sided tape so that the surface containing the cut pile faced upwards. The surface potential of the cut pile seal material fixed to the fixing stand was measured using a surface potential probe (Model 555-P1: Trek Inc.) and a surface potential meter (Model 344: Trek Inc.) to obtain the surface potential before friction. Next, as shown in Figure 8(b), after obtaining the surface potential before friction, a rotating body with an outer surface made of iron was brought into contact with the surface of the cut pile seal material fixed to the fixing stand, and the rotating body was rotated at a surface speed of 214 mm / sec for 30 seconds, after which the rotation was stopped. Next, as shown in Figure 8(c), within 10 seconds after the rotation of the rotating body stopped, the surface potential of the cut pile seal material fixed to the fixing stand was measured to obtain the surface potential after friction. Table 3 shows the evaluation results of the charging characteristics of the cut pile.

[0061] [Table 3]

[0062] As shown in Table 3, in cut pile sealing materials 1 to 3, the surface potential after friction is lower than the surface potential before friction. Therefore, it was shown that cut piles made from PTFE, acrylic, or bellima fibers have a charging characteristic in which frictional charging with iron is negative. On the other hand, in cut pile sealing material 4, the surface potential after friction is higher than the surface potential before friction. Therefore, it was shown that cut piles made from rayon fibers have a charging characteristic in which frictional charging with iron is positive.

[0063] [Evaluation of sealing properties for two-component developers] In the conceptual diagram of the horizontal cross-section of the developing apparatus shown in Figure 2, developing apparatuses 1 to 4 were prepared, each using cut pile sealing materials 3 to 6 as the first cut pile sealing material 347 and the second cut pile sealing material 348. A two-component developer (RICOH 8400: manufactured by Ricoh Co., Ltd.) was placed inside the housing 340 of the prepared developing apparatuses 1 to 4. The first stirring screw 341 and the second stirring screw 342 of developing apparatuses 1 to 4, which contained the two-component developer, were rotated at a rotational speed of 761 rpm for 200 hours.

[0064] In developing devices 1 to 4, during the rotation of the first stirring screw 341 and the second stirring screw 342, the time at which leakage of the two-component developer occurred from the gap between the rotating shaft 342a and the second insertion hole SIH, located in the direction of arrow Q, was checked every 10 hours. Table 4 shows the confirmed time at which leakage of the two-component developer occurred.

[0065] [Table 4]

[0066] As shown in Table 4, developing apparatuses 1-3, to which cut pile sealing materials 3-5 were applied, experienced leakage of the two-component developer within 200 hours. On the other hand, developing apparatus 4, to which cut pile sealing material 6 was applied, did not experience any leakage of the two-component developer within 200 hours. From this, it was experimentally demonstrated that cut pile sealing materials having a stripe configuration on their surface, in which the first cut pile made of acrylic fibers and the second cut pile made of rayon fibers each form lines, have excellent sealing properties against two-component developers.

[0067] Furthermore, as shown in Table 4, the surfaces of cut pile seal materials 3 to 5 have a configuration in which cut piles with either positive or negative triboelectric charge with iron are present. On the other hand, the surface of cut pile seal material 6 has a stripe configuration in which first cut piles with negative triboelectric charge characteristics with iron and second cut piles with positive triboelectric charge characteristics with iron each form a line. From this, it was experimentally suggested that cut pile seal materials having a stripe configuration on their surface in which first cut piles with negative triboelectric charge characteristics with iron and second cut piles with positive triboelectric charge characteristics with iron each form a line have excellent sealing properties with respect to two-component developers. [Explanation of Symbols]

[0068] 1. Image forming apparatus 10 Paper storage section 20 Paper feed rollers 30 Image forming unit 31 Photoconductor Drum 32 Charging device 33 Exposure Unit 34. Developing equipment 340 cabinets 340a Partition wall 341 First stirring screw 341a Rotation axis of the first stirring screw 341b Helical blades of the first stirring screw 342 Second stirring screw 342a Rotation axis of the second stirring screw 342b Helical blades of the second stirring screw 343 Developing Roller 343a Rotation axis of the developing roller 343b Magnetic body 344 Regulatory Blade 345 Toner Regulations Guide 346 Magnetic sealing material 347 First Cut Pile Seal Material 348 Second cut pile sealing material 349 Third cut pile sealing material 35 Paper transport path 36 Resist Rollers 37 Transfer Roller 38 Cleaning device 40 Toner storage compartment 50 Fixing device 60 Paper output roller 70 Paper output section 100 Cut Pile Woven Fabric 120 Retaining member 110 First Cut Pile 120 Second cut pile 130 Fabric part 200 Retaining member 200a Aiguchi

Claims

1. A cut pile sealing material for sealing a two-component developer, The aforementioned cut pile sealing material has at least two types of cut piles, The at least two types of cut pile each constitute a stripe that forms a line on the surface of the cut pile sealing material. The aforementioned at least two types of cut pile are, The first cut pile has a charge characteristic in which frictional charging with iron results in negative charge, The second cut pile has a charge characteristic in which frictional charging with iron results in positive charge, including, Cut pile sealing material.

2. The first cut pile is a cut pile composed of at least one fiber material selected from polytetrafluoroethylene, acrylic, and bellima. The aforementioned second cut pile is a cut pile composed of at least one fiber material selected from rayon, nylon, and cotton. The cut pile sealing material according to claim 1.

3. The aforementioned first cut pile is a cut pile made of acrylic fibers, The aforementioned second cut pile is a cut pile composed of rayon fibers. The cut pile sealing material according to claim 2.

4. The cut pile sealing material according to claim 3, wherein the cut pile sealing material has two types of cut piles consisting of the first cut pile and the second cut pile.

5. The charge characteristics are evaluated based on the difference in surface potential between the surface of a cut pile sealing material having only one type of cut pile as the test specimen and iron, before and after friction, according to claim 1.

6. The aforementioned charging characteristics are evaluated in accordance with surface potential measurement using a non-contact electrostatic electrometer as described in Japanese Industrial Standard JIS C 61340-2-2:2013 3.1c), as described in Claim 1 of the cut pile sealing material.

7. A developing apparatus employing a two-component developing method, having a cut pile seal material according to any one of claims 1 to 6.

8. The developing apparatus is A housing for storing the aforementioned two-component developer, A stirring screw for stirring the two-component developer housed in the aforementioned housing, Includes, The stirring screw has a rotating shaft that is rotatably supported in the housing, The housing has an insertion hole into which the rotating shaft is inserted, The cut pile sealing material is positioned in the gap between the rotating shaft and the insertion hole. The developing apparatus according to claim 7.

9. An image forming apparatus employing a two-component development method, comprising the developing apparatus described in claim 7.

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