JP4759167B2 - Method and apparatus for manufacturing foam roller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a foam roller manufacturing method and a manufacturing apparatus thereof. More specifically, the present invention relates to a method for manufacturing a foam roller capable of forming a foamed elastic layer uniformly and a manufacturing apparatus therefor.
[0002]
[Prior art]
In an image forming apparatus such as a dry electrophotographic apparatus, generally, a roller having a foamed elastic layer formed on the outer periphery of a rotating shaft, such as a developing roller, a transfer roller, a cleaning roller, and a paper feeding roller, is used.
These so-called foam rollers are generally manufactured by an integral foam molding method in which a foam-forming material is poured into a cylindrical mold having a rotating shaft set therein and foamed and cured.
[0003]
FIG. 3 is a cross-sectional view of a mold for explaining a conventional foam roller in-mold integral foam molding method, wherein 11 is a cradle, 12 is a cylindrical mold (mold), and 13 is a rotating shaft. ing. The rotary shaft 13 is set vertically at the center of the mold 12, and the foam forming material 14 is injected from the upper opening of the mold 12 to foam in the mold and solidify to form a foamed elastic layer on the outer periphery of the rotary shaft 13. A foamed elastic layer is formed on the portion 15.
Reference numeral 16 denotes a stopper, which is attached at the stage of foaming up to the upper end of the mold, but if 1 to 4 air vent holes with a diameter of about 0.1 to 1 mm are provided, it is attached immediately after injection of the foam-forming material. I can do it.
[0004]
This method is excellent in productivity because it does not require a cutting process or a grinding process after demolding. However, if the foam forming material 14 is injected from the upper opening of the mold 12, air is entrained. There was a drawback that the foamed elastic body layer was not uniformly formed due to local generation of porosity.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a method and apparatus for producing a foam roller that eliminates the above-mentioned drawbacks and can form a foamed elastic layer uniformly with a simple method and apparatus. .
[0006]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have divided the cylindrical member in the mold into a lower cylindrical member and an upper cylindrical member as a method that can achieve the above object, After injecting the foam-forming material into the cylindrical member, the inventors have invented a method in which the lower cylindrical member and the upper cylindrical member are relatively moved up and down to be connected and foamed in the upper and lower cylindrical members.
[0007]
In this case, the rotating shaft can be set in the lower cylindrical member in advance, or the rotating shaft can be moved together with the upper cylindrical member to be set in the lower cylindrical member.
In addition, when connecting the lower cylindrical member and the upper cylindrical body, the lower portion of the upper cylindrical body is fitted and connected to the lower cylindrical body, or the upper end edge of the lower cylindrical body and the lower end edge of the upper cylindrical body are joined. You may connect.
[0008]
The foam roller manufacturing apparatus is an apparatus for manufacturing a foam roller by forming a foam elastic body layer on the outer periphery of a rotating shaft by in-mold foam molding of a foam forming material. A cylindrical member and an upper cylindrical member are divided and connected by moving the lower cylindrical member and the upper cylindrical member relatively up and down.
[0009]
In this case, the inner diameter of the lower cylindrical member is set so that at least the lower part of the upper cylindrical member is inserted, and the lower part of the upper cylindrical member is fitted into the lower cylindrical member by relative movement between the upper cylindrical member and the lower cylindrical member. The lower cylindrical member and the upper cylindrical member have the same inner diameter, and the lower cylindrical edge of the upper cylindrical member and the upper cylindrical edge of the lower cylindrical member are moved by relative movement between the upper cylindrical member and the lower cylindrical member. Can be joined and connected.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the present invention will be described with reference to FIGS. 1 and 2. In the foam roller manufacturing method of the present invention, a foamed elastic layer is formed on the outer periphery of the rotary shaft 6 by foam molding of a foam-forming material. A method for producing a foam roller by forming the cylindrical member 2 in a molding die into a lower cylindrical member 3 and an upper cylindrical member 4 and injecting the foam forming material 5 into the lower cylindrical member 3. Then, before or immediately after the foam forming material 5 starts foaming, the lower cylindrical member 3 and the upper cylindrical member 4 are moved up and down relatively, as shown in FIGS. 1 (a) and 1 (b). Or connected as shown in FIGS. 2A and 2B and foamed in the upper and lower cylindrical members 3 and 4. In the figure, 1 is a cradle.
[0011]
The rotating shaft 6 is set in the lower cylindrical member 3 in advance. However, the rotating shaft 6 can be set in the lower cylindrical member 3 by moving (lowering) the rotating shaft 6 synchronously with the upper cylindrical member 4.
Although not shown in FIGS. 1 and 2, a stopper is used as in the conventional method described in FIG. The plug may be provided when the foam-forming material is foamed to the upper end of the mold, but a stopper provided with an air vent hole is attached to the upper end of the upper cylindrical member before connection to the lower cylindrical member. Also good.
[0012]
In the example of FIG. 1, in the foam roller manufacturing apparatus, the lower cylindrical member 3 has an inner diameter into which at least the lower portion 4a of the upper cylindrical member 4 is inserted. From the state shown in FIG. By relative movement between the lower cylindrical member 3 and the lower cylindrical member 3, the lower cylindrical portion 4a of the upper cylindrical member 4 is fitted into and connected to the lower cylindrical member 3 as shown in FIG.
In the example of FIG. 2, the lower cylindrical member 3 and the upper cylindrical member 4 have the same inner diameter. From the state shown in (a), the relative movement between the upper cylindrical member 4 and the lower cylindrical member 3 (b ), The lower end edge 4B of the upper cylindrical member 4 and the upper end edge 3b of the lower cylindrical member 3 are joined and connected. In this case, the joint end surface of the lower cylindrical member 3 and the upper cylindrical member 4 may be formed with engagement step nodes that engage with each other so as to be reliably bonded at a predetermined position.
[0013]
The sizes of the lower cylindrical member 3 and the upper cylindrical member 4 differ depending on the connection method, but the internal shape and size formed in the connected state must correspond to the shape and size of the foamed elastic body. That is, when connecting by fitting as shown in FIG. 1, only the upper cylindrical member 4 needs to correspond to the shape and size of the foamed elastic body, and when connecting by joining as shown in FIG. 3 and the upper cylindrical member 4 need to correspond to the shape and size of the foamed elastic body.
On the other hand, the inner volume of the lower cylindrical member needs to be equal to or greater than the volume before foaming of the foam-forming material to be used. To obtain the maximum effect of the present invention, foaming of the foam-forming material to be used is required. The capacity is preferably as close as possible to the previous capacity.
Further, the surface of the cylindrical member forming the surface of the foamed elastic body, that is, the inner surface of the upper cylindrical member 4 when connected by fitting as shown in FIG. 1, or the lower cylindrical member 3 when connected by joining as shown in FIG. The inner surface of both the upper cylindrical member and the upper cylindrical member may be imparted with an appropriate surface roughness on the surface of the foamed elastic body as a rough surface by the method previously proposed by the present inventors as Japanese Patent Application No. 2001-135881. .
[0014]
The material of the cylindrical member 2 is not particularly specified, and in addition to metals such as iron, copper, aluminum and stainless steel, polycarbonate, polyamide, polyacetal, polybutylene terephthalate, polyphenylene oxide, polyphenylene Engineering plastics such as ether, polyethersulfone, polysulfone, and polyphenylene sulfide, and ceramics can be used, but stainless steel is most suitable in terms of strength and cost.
[0015]
Next, specific examples will be described.
In the case of the implementation according to FIG. 1, after setting the rotating shaft 6 in the lower cylindrical member 3, a predetermined amount of polyurethane foam forming material is cast in the lower cylindrical member 3, and before or immediately after the start of foaming, fluorine is used. The upper cylindrical member 4 coated with a silicone-based or silicone-based release agent is lowered and the lower part 4a is fitted into the lower cylindrical member 3, and the temperature is usually in the range of 15 to 80 ° C, preferably 20 to 65 ° C. Initiate foaming. Next, after the voids in the mold are filled with polyurethane foam, curing is performed at a temperature of about 70 to 120 ° C., and then demolding is performed, whereby the foamed elastic layer formed by the foamed elastic layer forming unit 7 To obtain a foam roller.
In the case of the implementation according to FIG. 2, after setting the rotating shaft 6 in the lower cylindrical member 3, a predetermined amount of polyurethane foam-forming material is cast into the lower cylindrical member 3, before or after the start of foaming, The upper cylindrical member 4 coated with a fluorine-based or silicone-based release agent is lowered, and the lower end edge 4b and the upper end edge 3b of the lower cylindrical member 3 are joined and connected. Foam as in the case.
[0016]
The time from when the foam-forming material is injected and the lower cylindrical member 3 is filled with foaming varies depending on the composition and temperature of the foam-forming material and is not uniform, but is usually 2 to 20 seconds. And the upper cylindrical member need to be connected within the time from the injection of the foam-forming material.
[0017]
Examples of the rotating shaft include a metal member obtained by plating a steel material such as sulfur free-cutting steel with zinc or the like, and a metal member such as aluminum, stainless steel, or magnesium alloy.
The material for forming the foamed elastic layer in the foam roller is not particularly limited, and may be any of polyurethane foam layer, silicone rubber foam layer, EPDM foam layer, and the like. A roller in which a polyurethane foam layer is provided on the outer periphery of the rotating shaft is hereinafter referred to as a polyurethane foam roller).
In the production of the polyurethane foam roller, as the polyurethane foam forming material, a material containing a polyol component, a polyisocyanate component, a foaming agent and optionally used conductivity imparting agent, catalyst, foam stabilizer and the like is used. .
In the polyurethane foam-forming material, the polyol component and the polyisocyanate component may be contained in the form of a prepolymer obtained by reacting them.
[0018]
There is no restriction | limiting in particular as a polyol component used for manufacture of a polyol or a prepolymer, Polyether polyol, polyester polyol, hydrophobic polyol, etc. can be mentioned. Here, as the polyether polyol, polyols such as polyols obtained by addition polymerization of ethylene oxide or propylene oxide to glycerin or the like, polytetramethylene glycol, ethylene glycol, propanediol, butanediol and the like are preferably used. Polyester polyols include condensed polyester polyols obtained by condensation of dicarboxylic acids with diols and triols, lactone polyester polyols obtained by ring-opening polymerization of lactones based on diols and triols, and polyether polyols with lactone ends. A polyol such as an ester-modified polyol modified with an ester is preferably used. As the hydrophobic polyol, polyisoprene polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, or the like is used. These polyol components may be used alone or in combination of two or more.
[0019]
On the other hand, polyisocyanate components used for the production of polyisocyanates or prepolymers include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate (crude MDI), isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate; Diisocyanate; polyisocyanates having no unsaturated bond such as hexamethylene diisocyanate, and their modified products by isocyanurate, carbodiimide, glycol, and the like. These polyisocyanate components may be used singly or in combination of two or more.
[0020]
Next, as the foaming agent, a physical foaming agent generally having a boiling point in the range of 20 to 60 ° C. is preferably used in consideration of ease of handling in the production process, ease of vaporization and foaming. When this foaming agent is used as a raw material for polyurethane foam, the foaming agent alone has a low viscosity, and it is difficult to obtain a stable flow rate with a foaming machine. It is advantageous.
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), Freon 22 (chlorodifluoromethane), water and the like. These may be used alone or in combination of two or more.
[0021]
Next, in the polyurethane foam forming 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.
[0022]
These conductivity-imparting agents may be used singly 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.
[0023]
Further, in the polyurethane foam-forming material, the foam stabilizer used as desired includes, for example, polyether silicone oil, nonionic surfactant, ionic surfactant and the like, and these may be used alone. Two or more kinds may be used in combination.
[0024]
【The invention's effect】
According to the foam roller manufacturing method of the present invention, the cylindrical member in the mold is divided into the lower cylindrical member and the upper cylindrical member, and after the foam forming material is injected into the lower cylindrical member, the lower cylindrical member and the upper cylindrical member are injected. Since this is a method in which cylindrical members are connected and foamed in the mold, there is no risk of air being entrained in the mold when the foam-forming material is injected. It can be reliably formed on the outer periphery of the rotating shaft.
[0025]
In addition, according to the foam roller manufacturing apparatus of the present invention, a particularly complicated configuration is not adopted, and a simple configuration can be realized.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a molding die showing an embodiment of a foam roller manufacturing apparatus according to the present invention, in which (a) shows a state before a lower cylindrical member and an upper cylindrical member are coupled to each other. , (B) shows the state after connection.
FIG. 2 is a cross-sectional view schematically showing a molding die showing another embodiment of the foam roller manufacturing apparatus according to the present invention, in which (a) shows a state before connecting the lower cylindrical member and the upper cylindrical member. The state (b) shows the state after connection.
FIG. 3 is a schematic cross-sectional view showing a mold in a conventional foam roller manufacturing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base 2 Cylindrical member 3 Lower cylindrical member 3b Upper end edge 4 Upper cylindrical member 4a Lower part 4b Lower end edge 5 Foam forming material 6 Rotating shaft 7 Foam elastic layer forming part

Claims (5)

A method of manufacturing a foam roller to form a foamed elastic layer on the outer periphery of the rotating shaft by mold foaming of the foam forming material, the cylindrical member in the mold and a lower cylindrical member and the upper cylindrical member Then, after injecting the foam forming material into the lower cylindrical member, the lower cylindrical member and the upper cylindrical member are moved up and down relatively to obtain an upper end edge of the lower cylindrical body and a lower end edge of the upper cylindrical body. A method of manufacturing a foam roller, wherein the foam roller is joined and connected and foamed in upper and lower cylindrical members. A method of manufacturing a foam roller by forming a foam elastic body layer on the outer periphery of a rotating shaft by foam molding of a foam-forming material, wherein a cylindrical member in the molding die includes an outer cylindrical member for a lower part and an inner cylindrical member The foam forming material is injected into the lower outer cylindrical member, and then the lower outer cylindrical member and the inner cylindrical member are moved up and down relatively to lower the lower part of the inner cylindrical body. A method of manufacturing a foam roller, characterized by fitting and connecting in a cylindrical body and foaming in an internal cylindrical member. The method for producing a foam roller according to claim 1 or 2, wherein the rotary shaft is set in advance in the lower cylindrical member or the lower external cylindrical member . The method of manufacturing a foam roller according to claim 1 or 2, wherein the rotating shaft is moved together with the upper cylindrical member and set in the lower cylindrical member or the lower outer cylindrical member . An apparatus for producing a foam roller to form a foamed elastic layer on the outer periphery of the rotating shaft by mold foaming of the foam forming material, the cylindrical member in the mold and a lower cylindrical member and the upper cylindrical member The lower cylindrical member and the upper cylindrical member have the same inner diameter, and by moving the lower cylindrical member and the upper cylindrical member relatively up and down , the lower edge of the upper cylindrical member and the upper edge of the lower cylindrical member And an apparatus for manufacturing a foam roller , wherein the two are joined and connected.

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