JP2007130841A - Molding method of elastomer roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an elastomer roller capable of preheating a cylindrical mold in a short time without requiring a wide installation space when the elastomer roller is formed by injecting an elastomer material in the periphery of the core metal arranged in the hollow part of cylindrical mold. <P>SOLUTION: In the molding method of the elastomer roller for preheating the cylindrical mold by electromagnetic induction heating, the cylindrical mold is preheated along with the core metal after the core metal is arranged in the hollow part of the cylindrical mold. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  According to the present invention, an elastic material is formed around a core metal disposed in a hollow portion of a cylindrical mold to form an elastic layer, and the cylindrical mold is preheated to a predetermined temperature before the injection. The present invention relates to a method for manufacturing a body roller, and more particularly to an apparatus that does not require space and that can be preheated in a short time.

  Various elastic rollers such as a charging roller that distributes electric charge to a photosensitive drum are used in copying machines and printers. Such an elastic roller is generally shown in a longitudinal sectional view in FIG. As shown, it has a metal core 1 and an elastic layer 2 disposed around it. In order to manufacture such an elastic body roller 10, for example, as shown in a cross-sectional view in FIG. 2, the core metal 1 is disposed in the hollow portion 22 of the cylindrical mold 21, and then the liquid is obtained by mechanical flossing. A liquid foam in which bubbles are dispersed by mixing a resin or rubber material and gas is prepared, and this liquid foam is injected into the hollow portion 22 of the mold from one end thereof, and the inside of the mold 21 is filled. A method is known in which after being filled with a liquid foam, this is heated and cured (see, for example, Patent Document 1).

  Here, a cap 5 for defining both ends of the cavity 11 corresponding to the elastic layer 2 is attached to each end of the core metal 1, and each cap 5 is provided with a hole 5 a leading to the cavity 11. These holes 5a serve as injection ports for injecting material in the cap 5 on one side of the mold for injecting material, and the cap 5 on the other side of the mold discharges air in the cavity 11 at the time of material injection. To function as an exhaust port.

  As a method for forming the foam-like elastic layer 2 in place of the mecha-floss method, a method using a water foaming method is also known, which forms the elastic layer 2 at a low pressure using water as a foaming agent. .

When the elastic material forming the elastic layer 2 is injected into the hollow portion 22 of such a cylindrical mold 21, if the temperature of the mold 21 or the core metal 1 is low, the viscosity of the material is lowered and the fluidity is lowered. As a result, the injection may become incomplete and an injection failure may occur. Therefore, it is common to preheat the mold 21 and the core metal 1 and raise the temperature before injecting the material into the hollow portion 22. Conventionally, such preheating has been performed by storing the cylindrical mold 21 and the core metal 1 in a heating oven and heating them, or by blowing hot air on them (for example, (See Patent Document 1).
Japanese Patent Application Laid-Open No. 08-296331

  However, the method of preheating in the heating oven firstly requires a large installation space, and secondly, since the heating oven has low heating efficiency, it takes time to preheat until reaching a predetermined temperature. For this reason, the mold must stay in the heating oven for a long time, and when the elastic roller is continuously produced with a short tact time, at least the mold for the stay in the heating oven is used. Due to the fact that it is necessary to hold extra, the cost of the elastic roller has been greatly increased, which has been a problem.

  The present invention has been made in view of such problems, and when forming an elastic roller by injecting an elastic material around a cored bar disposed in a hollow part of a cylindrical mold, An object of the present invention is to provide an elastic roller manufacturing method in which a cylindrical mold can be preheated in a short time without requiring a large installation space.

<1> forms an elastic layer by injecting an elastic material around the core metal disposed in the hollow portion of the cylindrical mold, and preheats the cylindrical mold to a predetermined temperature prior to the injection. In the method of manufacturing an elastic roller,
In this method, the cylindrical mold is preheated by electromagnetic induction heating.

  <2> is a method for forming an elastic roller according to <1>, in which the cylindrical mold is preheated after the cored bar is disposed in the hollow part of the cylindrical mold.

  <3> is the preheating performed after placing the cored bar in the hollow part of the cylindrical mold in <2> as the second preheating, and only the cored bar as the first preheating prior to the second preheating. Is a method of forming an elastic roller that is preheated before being placed in the hollow portion of the cylindrical mold.

  According to the invention of <1>, since the cylindrical mold is preheated by electromagnetic induction heating with high thermal efficiency, the mold can be preheated in a short time, and the number of molds retained in the preheating process is minimized. Thus, the cost of the mold can be reduced, and the heating device by electromagnetic induction only needs to have a space for allowing the mold to pass through the coil for electromagnetic induction. Can also contribute.

  According to <2>, since the preheating of the cylindrical mold is performed with the core metal after the core metal is arranged in the hollow portion of the cylindrical mold, the core metal that affects the poor injection of the material is also short. Can be preheated in time.

  <3> According to <3>, the preheating performed after arranging the cored bar in the hollow part of the cylindrical mold is a secondary preheating, and only the cored bar is used as the primary preheating prior to the second preheating. Unlike the mold that is recirculated and remains with residual heat, it is preheated before it is placed in the hollow part of the metal mold. The temperature after the second preheating can be raised to a temperature equivalent to that of the mold, and defective injection can be more effectively prevented.

  According to the present invention, an elastic layer is formed by injecting an elastic material around a core metal disposed in a hollow portion of a cylindrical mold, and the cylindrical mold is placed at a predetermined temperature prior to the injection. First, the elastic roller according to the present invention will be described. As shown in FIG. 1, the elastic roller 10 includes a cored bar 1 and an elastic layer 2 disposed around the cored bar 1.

  There is no restriction | limiting in particular as the elastic layer 2 in the elastic body roller 10, As mentioned above, what was formed by inject | pouring an elastic body material into a cavity and hardening by foaming methods, such as a mechanical floss method or a water foaming method. Can be used.

  The polyurethane material when the elastic layer 2 is formed of polyurethane foam is not particularly limited as long as it contains a urethane bond in the resin. Examples of the polyol component include polyether polyol, polytetramethylene ether glycol, THF-alkylene oxide copolymer polyol, polyester polyol, acrylic polyol, polyolefin polyol, partially saponified product of ethylene-vinyl acetate copolymer, and phosphate system. Polyols, halogen-containing polyols and the like can be suitably used.

  The isocyanate component is not particularly limited, and not only general-purpose TDI, MDI, crude-MDI (polymeric MDI), and modified MDI, but also a special isocyanate may be used. Examples of the special isocyanate include 1,5-naphthalene diisocyanate, tolidine diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, p-phenylene diisocyanate, transcyclohexane 1,4 diisocyanate, xylylene diisocyanate (XDI), hydrogenated-XDI, and water. Addition-MDI, lysine diisocyanate, triphenylmethane triisocyanate, tris (isocyanate phenyl) thiophosphate, tetramethylxylene diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4- Isocyanatomethyloctane, 1,3,6-hexamethylene triisocyanate, bicycloheptane triiso Aneto, include trimethyl hexamethylene diisocyanate, and they can be used also suitable.

  In the polyurethane material, in addition to these polyurethane raw materials, a crosslinking agent, a foaming agent (water, low-boiling substances, gas bodies, etc.), a surfactant, a catalyst, a foam stabilizer, etc. can be added as desired. Thereby, it can be set as the layer structure as desired.

  In the case of the foaming method, a physical foaming agent generally having a boiling point in the range of 20 to 60 ° C. is preferably used as the foaming agent in consideration of ease of use in the manufacturing process, easiness of vaporization and foaming, and the like. . When such a foaming agent is used as a raw material for the polyurethane foam layer 2, the foaming agent alone has a low viscosity and it is difficult to obtain a stable flow rate in a foaming machine. It is advantageous to use. Specific examples of such foaming agents include n-pentane, isopentane, cyclopentane, methylene chloride, Freon 134a (1,1,1,2-tetrafluoroethane), Freon 245fa (1,1, 1,3,3-pentafluoropropane), Freon 365mfc (1,1,1,3,3-pentafluorobutane), Freon 356, Freon 141b (1,1-dichloro-1-fluoroethane), Freon 142b ( 1-chloro-1,1-difluoroethane) and Freon 22 (chlorodifluoromethane). These may be used alone or in combination of two or more.

  Examples of the catalyst include, for example, organometallic catalysts dibutyltin dilaurate, dibutyltin diacetate, stannous octoate, dibutyltin marker peptide, dibutyltin thiocarboxylate, dibutyltin dimalenate, dioctyltin marker peptide, dioctyltin thiocarboxylate. Rate, phenylmercury, silver propionate, tin octenoate, amine-catalyzed triethylamine, N, N, N ′, N′-tetramethylethylenediamine, triethylenediamine, N-methylmorpholine, dimethylaminoethanol, bis (2-dimethylamino) Ethyl) ether, 1,8-diazabicyclo (5,4,0) -undecene-7 and the like are preferably used. These catalysts may be used alone or in combination of two or more.

  Examples of the foam stabilizer include polyether silicone oil, nonionic surfactant, ionic surfactant and the like, and these may be used alone or in combination of two or more.

  In the elastic material of the present invention, examples of the conductivity imparting agent used as desired include carbon black and ionic conductive agents. Examples of carbon black include gas black such as electrified black, ketjen black, and acetylene black, oil furnace black including ink black, thermal black, channel black, and lamp black. Examples of ionic conductive agents include dodecyltrimethylammonium such as tetraethylammonium, tetrabutylammonium, and lauryltrimethylammonium, octadecyltrimethylammonium such as stearyltrimethylammonium, hexadecyltrimethylammonium, benzyltrimethylammonium, and modified aliphatic dimethylethylammonium. Ammonium salts such as chlorate, chlorate, hydrochloride, bromate, iodate, borofluoride, sulfate, alkyl sulfate, carboxylate, sulfonate; lithium, sodium, calcium, Perchlorate, chlorate, hydrochloride, bromate, iodate, borofluoride, trifluoromethyl sulfate, sulfo of alkali metal or alkaline earth metal such as magnesium Such as salts, and the like.

  These conductivity imparting agents may be used alone or in combination of two or more. Further, the blending amount thereof is not particularly limited and is appropriately selected according to various situations. Usually, it is 0.1 to 40 parts by weight, preferably 0.3 to 20 parts by weight with respect to 100 parts by weight of the polymer material. It is blended at a ratio of Moreover, filler-type conductive agents, such as a metal powder and a metal oxide powder, can be added with said carbon black and an ionic conductive agent. Further, in the polyurethane foam-forming material, the catalyst used as desired includes, for example, organometallic catalysts such as dibutyltin dilaurate, dibutyltin diacetate, stannous octoate, dibutyltin marker butylide, dibutyltin thiocarboxylate, dibutyltin dimaleate. Neat, dioctyltin marker butyl, dioctyltin thiocarboxylate, phenylmercury, silver propionate, tin octenoate, amine-catalyzed triethylamine, N, N, N'N'-tetramethylethylenediamine, triethylenediamine, N-methylmorpholine , Dimethylaminoethanol, bis (2-dimethylaminoethyl) ether, 1,8-diazabicyclo (5,4,0) -undecene-7, and the like are preferably used. These catalysts may be used alone or in combination of two or more.

  When a surface layer is provided outside the elastic layer 2, the material on which the elastic layer 2 is formed around the shaft 1 is taken out of the mold, and then the surface layer material is applied to the outer surface of the elastic layer. The coating method may be dip coating, spray coating, or roll coater coating.

  FIG. 3 is a process diagram showing the process of forming the elastic roller 10 described above, and FIGS. 4 to 6 are schematic cross-sectional views showing the elastic roller in the middle of finishing in each process. Refer to these figures. The formation of the elastic roller 10 will be described.

  First, the core metal 1 is preheated in the first preheating step 31. Unlike the preheating of the mold, the preheating of the core 1 has no particular restriction on the residence time in the preheating process. Therefore, a heating oven can be used, and for example, hot air of 90 to 120 ° C. is used in the heating oven. The cored bar 1 can be sprayed and preheated. In this step, the temperature of the core metal 1 is raised from room temperature of about 20 ° C. to 50 to 120 ° C., preferably 100 to 120 ° C.

  Next, in the “core metal and cap assembly step 32”, as shown in FIG. 4, the caps 5 are assembled to both ends of the preheated core metal 1, and subsequently, “the core metal with cap and mold assembly step” 33 ”, the cored metal 13 with the cap is inserted into the hollow portion 22 of the mold 21 to form the cored mold 14 as shown in FIG.

  After the “core metal core with cap, mold assembling step 33”, the core metal mold 14 is passed through a second preheating step 35 (details will be described later), and then as shown in FIG. In the casting step 36, an elastic material is injected into the cavity 11 defined by both caps 5 in the hollow portion 22 of the cored mold 14 and then in the vulcanizing step 37, the vulcanizing oven The elastic body material is cured by curing the elastic body material 10 to form the elastic body roller 10. Here, the cored metal mold 14 becomes the product metal mold 17.

After the vulcanization is completed, the product-containing mold 17 is subjected to a cooling process 39 for facilitating the removal of the product from the mold 21, and the “product with cap, mold disassembling process 40” is performed. And the mold 21 are disassembled.

  When the mold 21 disassembled here is returned to the “core metal with cap, mold assembling step 33”, while the product 18 with cap is provided with a surface layer on the elastic roller 10, for example, After delivering to the coating process 41 by dip and forming a surface layer there, the cap 5 is removed in the “cap, product disassembly process 42”, and the elastic roller 10 as the final product is taken out to complete the series of processes. To do. Here, when the surface layer is not formed, the capped product 18 may be delivered directly from the “capped product, mold disassembling step 40” to the “cap, product disassembling step 42”.

  FIG. 7 illustrates an apparatus for realizing the process described above as a layout diagram, and the process will be described more specifically with reference to the layout diagram. In the figure, reference numeral 51 denotes a core metal stock for storing the core metal 1, and the core metal 1 stored therein is tact-fed on the core metal conveyor 50 to constitute the first preheating step 31. 52. The pre-heated core metal 1 is assembled with caps 5 at both ends thereof by a cap assembly machine 53 constituting the “core metal and cap assembly process 32”.

  The cored metal 13 with the cap discharged from the cap assembling machine 53 is transferred from the cored bar conveyor 50 through the overhead conveyor 55 to the cored bar inserting machine 61, where the mold sent from another overhead conveyor 79 is transferred. After being inserted into the hollow portion 21, the cored metal mold 14 is formed and discharged onto the first mold conveyor 60 (“core metal with cap, mold assembling step 33”).

  When the cored mold 14 is further tact-fed by the first mold conveyor 60 and reaches the preheating conveyor 66, the electromagnetic induction heating device 65 that performs the main function of the second preheating process is performed by the preheating conveyor 66. Then, after being preheated to a predetermined temperature, it is returned to the first mold conveyor 60. Immediately after that, as a casting process, the elastic material is injected into the cavity 11 of the cored mold 14 by the casting machine 67 to form the productd mold 17. At this time, since the cored metal mold 14 is sufficiently preheated, it does not cause poor injection.

  The product-containing mold 17 on the first mold conveyor 60 is transferred to the second mold conveyor 70 by the overhead conveyor 69 and is tact-fed on the second mold conveyor 70 to form the vulcanizing process 37. It is vulcanized while passing through the sulfur oven 71.

  The mold 17 containing the product after vulcanization passes through the cooling chamber 75 constituting the cooling process 39 and is decomposed into the mold 21 and the product 18 with the cap by the product take-out machine 76 (“Product with cap, mold decomposition”). Step 40 "), the mold 21 is collected by the cored bar inserter 61 for reuse, and the capped product 18 is transported to a coating process (not shown).

  In FIG. 7, reference numeral 77 denotes a product pull-in conveyor for drawing the product-containing mold 17 into the product take-out machine 76, and 78 denotes a product draw-out conveyor that pulls out the capped product 18 from the product take-out machine 76.

  8A is a partial cross-sectional view showing the electromagnetic induction heating device 65, and FIG. 8B is a schematic view showing the outline of the configuration. The electromagnetic induction heating device 65 holds and accommodates the coil 81 and the coil. And a coil power supply device 83 that applies an alternating current to the coil 81. When an alternating current is passed through the coil 81 using the coil power supply device 83, an alternating magnetic field H is formed in the hollow portion of the coil 81. At this time, an eddy current is generated in the conductor arranged in the magnetic field, and Joule heat is generated by the eddy current and the resistance of the conductor, but the electromagnetic induction heating device 65 is based on this principle. The conductor portion of the cored metal mold 14 disposed in the hollow portion, that is, the core metal 1 and the metal mold 21 is heated, and is characterized in that it can be heated in a short time.

  In FIG. 8 (b), 66 is a preheating conveyance conveyor which draws the cored metal mold 14 into the electromagnetic induction heating device 65 as described above. A gripping device 84 that grips and delivers the first mold conveyor 60, a traverse rail 85 that reciprocates the gripping device 84 between the first mold conveyor 60 and the electromagnetic induction heating device 65, and gripping The device 84 is constituted by a drive device (not shown) that is traversed, and the holding device 84 is preheated to a desired temperature by retaining the holding device 84 in the hollow portion of the coil 81 for a predetermined time while holding the cored die 14. can do.

  Here, in order to effectively preheat a die or the like by electromagnetic induction heating, it is preferable to select a material that easily generates eddy current and can efficiently convert this into heat. In addition to the requirements to enable efficient heating, it is necessary to select materials in consideration of the requirements for effectively exhibiting the original functions of the core 1 and the die 21, such as iron, SUS, etc. It is preferable to select a metal material.

  Under the condition that the cored metal mold 14 stays in the magnetic field formed in the hollow part of the coil 81 of the electromagnetic induction heating device 65 for 6 seconds, the core metallized mold 14 is secondarily preheated and then cast. Vulcanization was carried out, and this was taken as an example. And about the cored metal mold 14 just before the casting process 36 which passed through this 2nd preheating process 35, while measuring the temperature of the core metal 1 and the metal mold 21 which comprise this, in the casting process 36 The incidence of casting defects was examined.

  As a comparative example, for the cored mold 14 that has not undergone the second preheating process 35, the temperature of the cored bar 1 and the mold 21 immediately before the casting process 36 is measured, and the rate of occurrence of casting defects is also measured. Was compared with the examples. The results are shown in Table 1.

  In both the examples and the comparative examples, the first preheating of the cored bar 1 was performed. The temperature immediately before the second preheating of the core metal 1 and the mold 21 in the example was substantially the same as the temperature immediately before the casting process of the corresponding product of the comparative example.

The elastic roller used in this experiment is a charging roller in both the examples and the comparative examples. The cored bar 1 is made of iron, the diameter is 6 mm, and the length is 250 mm. The material was SUS, the outer diameter was 20 mm, the inner diameter was 10 mm, and the length was 290 mm.

  Here, the temperature of both the core 1 and the mold 21 was measured with a radiation thermometer. The occurrence of casting defects was determined by visual inspection of the finished appearance. The number of samples for calculating the casting defect rate was 100 for each of the examples and comparative examples.

  The present invention can be used for various elastic rollers having a foamed elastic layer. The elastic roller includes a charging roller for charging the photosensitive drum, and a non-magnetic magnetic toner according to the latent image formed on the photosensitive drum. Examples include a developing roller to be transferred, a toner supply roller for supplying toner to the developing roller, and a transfer roller for transferring the toner on the photosensitive drum to printing paper.

It is sectional drawing which shows the elastic body roller which concerns on this invention. It is sectional drawing of the metal mold | die for demonstrating the molding method of an elastic body roller. It is process drawing which shows the process of forming an elastic body roller. It is a schematic sectional drawing of the elastic body roller in the middle of finishing in a core metal and a cap assembly process. It is a schematic sectional drawing of the elastic body roller in the middle of finishing in the core metal with a cap and a die assembly process. It is a schematic sectional drawing of the elastic body roller in the middle of finishing in a casting process. 1 is a layout view showing an apparatus according to the present invention. It is sectional drawing and a conceptual diagram which show an electromagnetic induction heating apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Core metal 2 Elastic layer 5 Cap 5a Cap hole 10 Elastic roller 11 Cavity 13 Core metal with cap 14 Core metal mold 17 Product metal mold 18 Product with cap 21 Mold 22 Mold hollow part 31 Primary Preheating process 32 Core metal, cap assembly process 33 Cap metal core, mold assembly process 35 Secondary preheating process 36 Casting process 37 Vulcanization process 39 Cooling process 40 Capped product, mold disassembly process 41 Coating process 42 Cap, Product Disassembling Process 50 Core Bar Stock 51 Core Bar Conveyor 52 Heating Oven 53 Cap Assembly Machine 55 Overhead Conveyor 60 First Mold Conveyor 61 Core Bar Inserting Machine 63 Core Bar Die Retracting Machine 65 Electromagnetic Induction Heating Device 66 Preheating conveyor 67 Casting machine 69 Overhead conveyor 70 Second mold conveyor 71 Vulcanization Down 74 Products containing Mold dispensing machine 75 cooling chamber 76 product take-out machine 77 product retraction device 78 product drawing device 79 overhead conveyor

Claims (3)

Production of an elastic roller for injecting an elastic material around a core metal disposed in a hollow portion of a cylindrical mold to form an elastic layer and preheating the cylindrical mold to a predetermined temperature prior to the injection In the method
A method for forming an elastic roller, wherein the cylindrical mold is preheated by electromagnetic induction heating.   The method for forming an elastic roller according to claim 1, wherein the cylindrical die is preheated after the cored bar is disposed in the hollow part of the cylindrical mold and then the cored bar. The preheating performed after placing the cored bar in the hollow part of the cylindrical mold is the secondary preheating, and only the cored bar is used as the primary preheating prior to the secondary preheating in the hollow part of the cylindrical mold. The method for forming an elastic roller according to claim 2, wherein the elastic roller is preheated before being disposed.

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