JP2007237451A - Manufacturing method of rubber roll - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a rubber roll not requiring the process of polishing and cleaning the slide surface of a core or coating a mold release agent for avoiding adhesion, capable of suppressing the loss of a rubber material, the damage of the core metal or the contamination of the slide surface and an edge face and enabling extrusion of high precision reduced in the irregularity of an extrusion outer diameter. <P>SOLUTION: In the manufacturing method of the rubber roll for coating the outer peripheral surface of the core with the rubber material by a rubber extruder of a crosshead die system, a masking member for preventing the adhesion of the rubber material is respectively attached to both end parts of the core to be slide with respect to the inner surface of the core guide part provided in the head of the rubber extruder to cover the outer peripheral surface of the core while passing the core through the core guide part and detached. The masking member has a structure that a guide plate parallel to the longitudinal direction of the core is provided to the outer peripheral surface of the cylindrical shape part fitted to the end part of the core in order to determine the position of the core inside the core guide part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a rubber roll used for a paper feed roll, a charging roll, a transfer roll, a developing roll, a toner supply roll, a cleaning roll, etc. incorporated in a copying machine, a printer, or the like.

  In a method for manufacturing a rubber roll using a general crosshead extruder, a molding method in which a rubber material is coated while a core metal is passed through a crosshead die is manufactured by the following manufacturing method, for example.

  First, an adhesive for adhering the core metal and rubber is previously applied to the core metal. In the uniaxial rubber extruder 1 shown in FIG. 1, a core bar a whose position is determined by a core bar guide 5 is positioned at a substantially central portion where the rubber is extruded in a cylindrical shape within the extruder head 2. Will be sent by. Thereby, the rubber material b supplied to the outer periphery of the core metal is integrally covered in the core metal-rubber adhesion area. The core-rubber columnar integral c extruded from the die 6 at the tip of the extruder head through the coating area is separated to the length of each roll by a take-off cutting machine attached to the extruder.

  Furthermore, in such roll production, as a subsequent process, a cylindrical work having a roll length for each roll is subjected to heat treatment for vulcanization reaction. After the vulcanization reaction, the rubber part is cut to the required rubber length by the cutting blade 8 and unnecessary rubber material at the end part is removed, so that a rubber roll d having a cored bar sliding part is obtained. Then, it is carried to a grinding process etc. in order to process into a required outer diameter size and shape. In the figure, 3 is a cylinder pressure sensor, and 7 is a die axis adjusting pin.

  In this manufacturing method, the process of removing the rubber | gum of the metal core end part used as a sliding part after vulcanization | cure is included, and the following production technical problems have arisen. 1: Loss of unnecessary rubber material, 2: Metal core damage by blade inserted when cutting to required dimensions, 3: Metal core sliding surface and end surface contamination due to chemical fixation of rubber material and metal core.

  For this reason, in the above manufacturing method, it has been attempted to polish the core metal sliding surface or apply a release agent for preventing sticking to the sticking after removing unnecessary rubber, but the equipment burden is large. Further improvements are also desired. In order to prevent the damage to the core metal, in order to cut only the rubber without touching the core metal with the cutting blade, extremely high mechanical accuracy and precision of the blade are required. It is necessary to improve the management accuracy, and there is a need for improvement such as an increase in manufacturing cost.

  For such improvement, masking is applied to the sliding surface of the end of the metal core as described in Patent Document 1 to prevent damage to the metal core during cutting and contamination of the sliding surface. It can respond to the manufacture of products with outer diameters of.

However, in the above method, depending on the type and composition of the rubber, when the masking passes through the die die, the protruding pressure of the rubber may change, and the outer diameter of the extruded roll may not be stable. Was not necessarily suitable.
JP 2005-329639 A

  The object of the present invention is not to clean the core sliding surface after removing unnecessary rubber or to apply a release agent for preventing sticking, etc., 1: Loss of unnecessary rubber material, 2: Required Overcoming production technical issues such as core damage caused by blades inserted when cutting into dimensions, 3: Contamination of sliding surfaces and end faces of the core metal due to chemical adhesion between the rubber material and the core metal, and uneven extrusion outer diameter It is an object of the present invention to provide a method for producing a rubber roll that can be extruded with high accuracy and a small amount. The core bar sliding surface is a part of the core bar that slides with another member (bearing or the like) when using a rubber roll.

According to the present invention, in a method for producing a rubber roll in which the outer peripheral surface of a cored bar is covered with a rubber material by a rubber extruder using a crosshead die method,
a) attaching a masking member for preventing adhesion of the rubber material to both ends of the cored bar;
b) After step a, the cored bar is passed through the cored bar guide part by sliding the masking member against the inner surface of the cored bar guide part provided in the head of the rubber extruder. C) covering the outer peripheral surface with a rubber material; and c) removing the masking member after step b,
A guide plate parallel to the longitudinal direction of the core metal for defining the position of the core metal inside the core metal guide part on the outer peripheral surface of the cylindrical part that the masking member is fitted to the end of the core metal. There is provided a method for producing a rubber roll characterized by having a provided structure.

  According to the present invention, after removing unnecessary rubber, there is no need for polishing cleaning of the sliding surface of the core metal or applying a release agent for preventing sticking, etc .: 1: Loss of unnecessary rubber material, 2: Cutting to required dimensions Overcoming production technical issues such as core metal scratches caused by blades inserted during the process, and contamination of the core metal sliding surface and end surface due to chemical adhesion between the rubber material and the core metal. A method for producing a rubber roll capable of accurate extrusion is provided.

  Hereinafter, although one form of this invention is demonstrated in detail using figures, this invention is not limited by this.

  A crosshead type extruder capable of continuously covering a core metal with a rubber material (rubber compound) shown in FIG. 2 is used. An adhesive such as an adhesive mainly composed of a resin is applied to the core bar in order to adhere to the rubber part.

  A masking member E is attached to each end sliding portion of the metal core A where no adhesive is applied. The sliding portion is a portion that slides with another member (bearing or the like) when the rubber roll is used.

  The cored bar is supplied to a cored bar guide 15 provided in the head of the extruder by a cored bar feed roll conveyor 14 that intermittently supplies the cored bar.

  The crosshead extruder has, for example, a crosshead 12 having a screw diameter of 30 mm to 90 mm and passing through a mandrel in the rubber extruding direction and covering the mandrel with rubber at the tip of a uniaxial rubber extruder 11. In addition, as for the core metal to which masking was given, the thing of length of 200-350 mm is used according to the length of a product, for example.

  In the crosshead (die) 12, the core A passes through the core guide 15 and the rubber compound B adheres to the adhesive-coated portion where the masking member of the core A is not attached, in the area where the core meets the rubber. The outer peripheral surface of the metal core is partially covered with the rubber compound. The obtained roll shape is continuously extruded from a cylindrical die 16. In the figure, 13 is a cylinder pressure sensor, and 17 is a die axis adjusting pin.

  The extruded cored bar-rubber and masking columnar integral C are pulled apart to a length of one roll by a take-off cutting machine (not shown) attached to the extruder.

  Next, the roll D with the masking removed at both ends is transferred to a hot stove for vulcanization molding. When removing the masking, it can be removed while forming the required end face without stretching the unvulcanized rubber by removing the masking while rotating.

  The vulcanized roll is carried to a grinding process or the like in order to cut the rubber end portion after vulcanization into a necessary roll length dimension and process it into a necessary outer diameter dimension and shape as necessary.

  In this way, a rubber roll is obtained as a product. Further, the removed masking member can be washed and used again.

  The masking member is arranged in the longitudinal direction of the core bar (that is, the feed direction of the core bar) to define the position of the core bar inside the core bar guide part on the outer peripheral surface of the cylindrical part fitted to the end of the core bar. It has a structure in which a parallel guide plate is provided.

  When the metal core A is passed through the metal core guide part 15, the masking member is slid with respect to the inside of the metal core guide part. At this time, specifically, the guide plate comes into contact with the inside of the cored bar guide portion. The core metal itself does not contact the core metal guide part.

  As the masking member, it is preferable to use a masking member having a structure in which three or more guide plates are provided from the viewpoint of arranging the cored bar at the center of the roll axis during roll extrusion. FIG. 3A shows an example of a masking member having three guide plates. This masking member has a structure in which three guide plates 22 are provided on the outer peripheral surface of the cylindrical member 21 at a pitch of 120 °. In addition, at least a part of the inside of the cylindrical member is a hole 23 that engages with the end portion of the cored bar.

  A large number of guide plates may be provided, and the masking member may be gear-shaped. An example of a gear-shaped masking member is shown in FIG.

  As shown in FIG. 4, it is preferable that the diameter Dm of the circle connecting the tip points of the guide plate is more than 90% and less than 100% of the diameter (inner diameter) Dd of the extrusion die die 16 of the rubber extruder. That is, it is preferable that Dm / Dd exceeds 90% from the viewpoint of arranging the cored bar at the center of the roll axis during roll extrusion. Moreover, it is preferable that Dm / Dd is less than 100% from the viewpoint of the clearance between the die die and the guide plate.

  The height H of the guide plate is preferably 1% or more and 50% or less of the diameter Dm of the circle connecting the tip points of the guide plate. That is, when the masking at the time of extrusion passes through the die die, H / Dm is 1% or more from the viewpoint of alleviating the change in rubber pressure, which has been a problem in the past because the extruded rubber flows between the guide plates. It is preferable. Moreover, it is preferable that H / Dm is 50% or less from a viewpoint of ensuring the thickness as masking so that a metal core may not loosen.

  The rubber compound to be used is not particularly limited as long as it is a rubber that can be extruded using a single screw extruder and a crosshead die. For example, as rubber components, nitrile rubber (NBR), epichlorohydrin rubber (ECO, CO), ethylene / propylene rubber (EPDM, EPM), synthetic natural rubber (IR), styrene rubber (SBR), chloroprene rubber (CR), Examples thereof include butyl rubber (IIR), and these rubbers are used alone or in combination of two or more. In addition, other components used in general rubber, for example, reinforcing agents such as carbon black, fillers such as calcium carbonate, anti-aging agents, processing aids, zinc oxide, stearic acid, vulcanization accelerators, vulcanization An agent or the like can be contained as necessary.

  Examples of the present invention will be specifically described below.

[Example 1]
The metal core bar used as the shaft body was prepared by extruding an iron material into a bar having a diameter of 6 mm by extrusion molding, cutting to a length of 258 mm, and then applying a chemical nickel plating to this to a thickness of about 3 μm.

  A hot melt type conductive adhesive mainly composed of a styrene resin was uniformly applied to the core bar with a thickness of about 10 μm except for the portions from both ends to 12 mm.

  The masking member was formed as follows. First, the fluororesin was processed into a cylindrical shape having an outer diameter of 9.45 mm and a length of 16 mm. A cylindrical hole (diameter 6 mm, depth 12 mm) for fitting the end of the cored bar was formed in this column, and a hollow cylindrical product with a bottom was obtained. The inner surface of this hole has irregularities that fasten the cored bar with a certain strength. On the outer peripheral surface of the hollow cylindrical object, grooves having a depth of 1.5 mm are formed at a pitch of 15 ° parallel to the longitudinal direction (axial direction) of the hollow cylindrical object, as shown in FIG. A gear-shaped masking member was obtained.

  The aforementioned Dm is 9.45 mm, and H is the groove depth of 1.5 mm.

  The above-mentioned masking members were respectively covered on both ends of the core metal, and were fed intermittently at a rate of 2.5 mm / min to a core metal guide having an inner diameter of 9.7 mm in the crosshead die with a belt-type core metal feeder having a concave groove. .

  The extruder has the structure shown in FIG. 2 and is provided with a cross-head type cored bar and a rubber coating function in a uniaxial vent type extruder having a screw with an outer diameter of 60 mm, and the die diameter (diameter) of the die of the rubber protrusion is 9. The temperature is adjusted to about 40 ° C. for the entire head.

  As the rubber compound charged into the single screw vent extruder, NBR was used as a main polymer and carbon black, a plasticizer, a filler, a vulcanization accelerator and a vulcanizing agent were kneaded continuously.

  Using this apparatus, the metal core and the rubber compound are continuously integrated and discharged as a rubber roll from the die. At that time, the rubber compound adheres only to the unmasked portion of the core metal, and the roll sliding surface of both ends of the core metal is protected by the masking member.

  The rubber rolls discharged in this way are separated one by one by a roll take-up machine provided side by side, and the masking member is removed in the masking removal process in the middle of the next process conveyance.

  Thereafter, it is conveyed to a continuous hot stove at 200 ° C. by a conveyor and vulcanized for 40 minutes to obtain a product rubber roll.

  The removed masking is removed from the rubber attached by the washing machine and returned to the parts feeder for use.

[Example 2]
The masking member was formed as follows. First, the fluororesin was processed into a cylindrical shape having an outer diameter of 6.5 mm and a length of 16 mm. A cylindrical hole (diameter 6 mm, depth 12 mm) for fitting the end of the cored bar was formed in this column, and a hollow cylindrical product with a bottom was obtained. The inner surface of this hole has irregularities that fasten the cored bar with a certain strength. On the outer peripheral surface of this hollow cylindrical object, three plate-shaped guides having a height of 1.45 mm and a length of 16 mm are provided at a 120 ° pitch in parallel with the longitudinal direction (axial direction) of the hollow cylindrical object. A masking member having a shape as shown in 3 (a) was obtained.

  The aforementioned Dm is 9.4 mm, and H is 1.45 mm.

  The entire head of the extruder is temperature adjusted to about 30 ° C.

  Except for the above, a product rubber roll was obtained in the same manner as in Example 1.

[Example 3]
The masking member was formed as follows. First, the fluororesin was processed into a cylindrical shape having an outer diameter of 6.5 mm and a length of 16 mm. A cylindrical hole (diameter 6 mm, depth 12 mm) for fitting the end of the cored bar was formed in this column, and a hollow cylindrical product with a bottom was obtained. The inner surface of this hole has irregularities that fasten the cored bar with a certain strength. On the outer peripheral surface of this hollow cylindrical object, three plate-shaped guides with a height of 0.45 mm and a length of 16 mm are provided at a 120 ° pitch in parallel to the longitudinal direction (axial direction) of the hollow cylindrical object. A masking member having a shape as shown in 3 (a) was obtained.

The aforementioned Dm is 7.4 mm, and H is 0.45 mm.
The entire head of the extruder is temperature adjusted to about 30 ° C.

  Except for the above, a product rubber roll was obtained in the same manner as in Example 1.

[Comparative Example 1]
The masking member was formed as follows. First, the fluororesin was processed into a cylindrical shape having an outer diameter of 9.5 mm and a length of 16 mm. A cylindrical hole (diameter 6 mm, depth 12 mm) for fitting the end of the cored bar was formed in this column, and a hollow cylindrical product with a bottom was obtained. The inner surface of this hole has irregularities that fasten the cored bar with a certain strength. This hollow cylinder was used as a masking member.

  The aforementioned Dm is 9.5 mm.

  The entire head of the extruder is temperature adjusted to about 30 ° C.

  Except for the above, a product rubber roll was obtained in the same manner as in Example 1.

  While rotating the rubber rolls obtained in the above examples and comparative examples with reference to the sliding surface of the core metal, the outer diameter of the rubber roll part was measured at a 2-mm interval with a 105-point laser length measuring device at intervals of 2 mm. Table 1 shows values obtained by comparing the degree of variation in the outer diameter. In Examples 1 and 2, it can be seen from the value of the standard deviation σ that the outer diameter is formed stably. In Example 3, since the guide plate height and Dm are slightly smaller than the die base diameter, the eccentricity of the roll and the stability of the outer diameter are slightly inferior, but excellent results are obtained as compared with Comparative Example 1. .

It is a schematic diagram for demonstrating the manufacturing method of the conventional rubber roll. It is a schematic diagram for demonstrating the manufacturing method of the rubber roll by this invention. It is a schematic diagram which shows the example of the masking member which can be used in this invention. It is a schematic diagram which shows the example of the masking member which can be used in this invention. It is a schematic diagram which shows the masking member used in the comparative example.

Explanation of symbols

1,11 Uniaxial vent type extruder (uniaxial rubber extruder)
2,12 Crosshead (die)
3, 13 Cylinder pressure sensor 4 Core metal supply roll 14 Core metal supply roll conveyor 5, 15 Core metal guides 6, 16 Cap die 7, 17 Die axis adjustment pin 8 Cutting blade a Core metal with adhesive A Masking member is mounted Adhesive cored metal b, B Rubber compound c Extruded rubber coated roll C Extruded rubber coated roll d, D Rubber roll E Masking member

Claims (5)

In a method of manufacturing a rubber roll in which the outer peripheral surface of a core metal is covered with a rubber material by a rubber extruder using a crosshead die method,
a) attaching a masking member for preventing adhesion of the rubber material to both ends of the cored bar;
b) After step a, the cored bar is passed through the cored bar guide part by sliding the masking member against the inner surface of the cored bar guide part provided in the head of the rubber extruder. C) covering the outer peripheral surface with a rubber material; and c) removing the masking member after step b,
A guide plate parallel to the longitudinal direction of the core metal for defining the position of the core metal inside the core metal guide part on the outer peripheral surface of the cylindrical part that the masking member is fitted to the end of the core metal. A method for producing a rubber roll, comprising a provided structure.   The method according to claim 1, wherein a masking member having a structure in which three or more guide plates are provided is used as the masking member.   3. The method according to claim 1, wherein a diameter of a circle connecting the leading end points of the guide plate as the masking member is more than 90% and less than 100% of the diameter of the extrusion die of the rubber extruder.   The method according to any one of claims 1 to 3, wherein a height of the guide plate is not less than 1% and not more than 50% of a diameter of a circle connecting the tip points of the guide plate.   The method according to claim 1, wherein the masking member has a gear shape.

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