JP2003300239A - Method for producing rubber roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a rubber roller which has a core bar and is formed in a crown shape without using a cutting process and a mold having an individual crown shape. <P>SOLUTION: In the method for producing the rubber roller having a crown- shaped form by using a cross-head extruder 62, the amount of an unvulcanized rubber material to be supplied is stabilized to be a prescribed amount, and the moving speed of the core bar 1 in a die nozzle 43 is changed by the region in the longitudinal direction of the core bar 1 to change the circumferential diameter of the rubber roller in the longitudinal direction. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging roller, a paper feeding roller and the like (also referred to as a charging roller) used in an electrophotographic apparatus such as a printer and a copying machine, an office machine, etc. The present invention relates to a method of manufacturing a rubber roller in which both end portions are projected and the outer peripheral diameter is changed in the length direction so that the outer peripheral shape is covered with a rubber layer having a crown shape, a drum shape, or the like.

[0002]

2. Description of the Related Art Usually, a charging roller, a paper feeding roller and the like used in a printer, a copying machine and the like are often rotated by being pressed against a rotating photosensitive drum or the like with a predetermined pressure. This charging roller or the like is pressed against the photosensitive drum or the like by pressing the cored bar protruding at both ends of the roller, and therefore the cored bar is bent by this pressing force, and the rubber is distorted at both ends and the central part of the rubber layer ( The degree of compression is different, and the nip area of the pressure contact part with the photosensitive drum etc. (refers to the area of contact in a unit length)
Is large at both ends and small at the center. If the nip area is not uniform, for example, in the case of a paper feed roller, peripheral speed unevenness occurs in the longitudinal direction, causing skew and wrinkling of the paper, and when used as a charging roller, the electric field strength is in the length direction of the roller. It becomes non-uniform, uneven charging occurs, and defects occur in the image.

Conventionally, it has been known that the rubber roller has a crown shape in order to make the nip area uniform. After thoroughly kneading the unvulcanized rubber material at a specified temperature with an extruder, push it out at a specified speed, and apply it with a specified thickness on the outer circumference of the core metal with a crosshead die to form an unvulcanized rubber roller. Then, this is vulcanized to form a charging roller or the like.
As a method to create a crown shape on this rubber roller,
After vulcanization, the outer peripheral surface of the rubber roller is ground and polished into a crown shape by a lathe, etc., and an unvulcanized rubber roller is filled in a mold having a cavity molded into a crown shape in advance and vulcanization is performed at the same time. There is a way to create a shape.

[0004]

However, in the conventional crown forming method as described above, the number of manufacturing steps is increased in both the grinding method and the die method, and a large capital investment is required. Also, the number of man-hours required to manage various types of dies becomes large. Further, when the unvulcanized rubber material is adhered to the core metal by the crosshead die, small wrinkles may occur due to die swell that occurs in the die nozzle of the crosshead die.

The die swell means that the unvulcanized rubber material flows by heating and is an elastic body. When the unvulcanized rubber material is attached to the core metal and pushed out from the die nozzle, the unvulcanized rubber material is released from the extrusion pressure. It means to inflate.

An object of the present invention is to provide a method of manufacturing a rubber roller having a core metal and a crown shape formed on a rubber layer without requiring a grinding / polishing step or a die having an individual crown shape. .

[0007]

In order to solve the above-mentioned problems, a method of manufacturing a rubber roller according to claim 1 is characterized in that an unvulcanized rubber material is added to a crosshead die of a crosshead extrusion device at a substantially central portion of the unvulcanized rubber material. While supplying from the vulcanized rubber supply port, the core metal is fed from the core metal insertion port of the crosshead die into the core metal guide path, and the unvulcanized rubber material is provided along the core metal guide path and near the die nozzle. A method of manufacturing a rubber roller that sends out an unvulcanized rubber roller from a die nozzle while sending it to a rubber flow path that intersects with a cored bar guide path, while cylindrically covering the unvulcanized rubber material on the cored bar,
By changing the moving speed of the cored bar in the die nozzle in the lengthwise direction of the cored bar depending on the parts such as one end, center, and the other end, unvulcanized cylindrically adhered to the cored bar. It is characterized in that the outer diameter of the rubber material is changed along the longitudinal direction.

The amount of rubber (rubber layer thickness) applied to the core metal by the crosshead die of the crosshead extrusion device (referring to a rubber roller molding device having an extruder and a crosshead die) is unvulcanized rubber. When the amount of material supplied is constant, it is inversely proportional to the moving speed of the core metal. That is, when the moving speed of the core metal in the die nozzle is higher than the moving speed of the unvulcanized rubber material passing through the die nozzle (also referred to as discharge speed), the unvulcanized rubber material extruded to the crosshead die is Since the rubber is attached and moves while being stretched, the thickness of the rubber becomes thinner than the die-swelled thickness, and is adjusted to be thicker or thinner depending on the moving speed of the cored bar.

In this way, when the unvulcanized rubber material is cylindrically applied to the core metal by using the crosshead die, the moving speed of the core metal is kept constant while the extrusion amount of the unvulcanized rubber material is constant. It is possible to manufacture a rubber roller in which the film thickness of the unvulcanized rubber material, that is, the cylindrical outer peripheral diameter is changed along the longitudinal direction by the lengthwise portion of the core metal by changing the lengthwise portion of the core metal. it can. By subjecting this unvulcanized rubber roller to vulcanization finishing, a rubber roller whose outer peripheral shape is formed into a crown shape, a drum shape, a taper shape or the like can be obtained.

According to a second aspect of the present invention, in the method of manufacturing a rubber roller, the moving speed of the cored bar in the die nozzle is set to be high at one end of the cored bar and gradually slowed down toward the central part, and further from the central part. It is characterized in that the outer peripheral shape of the rubber roller is formed into a crown shape by gradually increasing the speed toward the end.

As described above, the moving speed of the cored bar in the die nozzle is set to be high at both ends of the cored bar and gradually reduced to the central part, so that the film thickness of the unvulcanized rubber material to be deposited is It is possible to manufacture a so-called crown-shaped rubber roller that is thin at both ends and thick at the center. The unvulcanized rubber roller is vulcanized to be suitably used as a charging roller or the like that comes into pressure contact with the photosensitive drum or the like.

According to a third aspect of the present invention, in the method for manufacturing a rubber roller, the rear end of the leading metal core, which is coated with the unvulcanized rubber material and extruded from the crosshead die, is always in contact with the leading end of the subsequent metal core. In addition, the following core metal is urged in the traveling direction.

When the moving speed of the succeeding mandrel becomes slower than the moving speed of the preceding mandrel which is being coated with the unvulcanized rubber material to form an unvulcanized rubber roller, it follows the preceding mandrel. A gap may be formed between the core metal and the unvulcanized rubber material may enter the gap. When the unvulcanized rubber material enters, the elasticity of the unvulcanized rubber material makes the gap between the cores unstable, and the amount of rubber required for a specific part (for example, the central part) of the core is covered. It becomes difficult to control the moving speed of the core metal so that it is worn. Therefore, the succeeding mandrel is constantly urged in the traveling direction so that the leading end of the mandrel is always brought into contact with the trailing end of the preceding mandrel. When the moving speed of the cored bar is reduced when the cored bar that follows is not biased, a gap may occur between the cored bars due to the flow of the unvulcanized rubber material or the inertia of the preceding cored bar.

The method of manufacturing a rubber roller according to a fourth aspect is characterized in that the moving speed of the core metal is higher than the moving speed of the unvulcanized rubber material passing through the die nozzle.

The moving speed of the core metal is the moving speed of the unvulcanized rubber material passing through the die nozzle (also referred to as discharge speed, since this speed changes from the surface of the core metal to the thickness direction, it is averaged in the thickness direction. The speed is set higher than the speed), and the unvulcanized rubber material die-swelled immediately after being discharged from the die nozzle is stretched to a predetermined thickness, and wrinkles due to the die swell are completely eliminated. Further, by increasing the moving speed of the core metal, it is possible to manufacture a rubber roller having an outer diameter smaller than the inner diameter of the nozzle.

According to a fifth aspect of the present invention, in the method for producing a rubber roller, a multi-layer extrusion crosshead die is used as the crosshead die, and a plurality of types of unvulcanized rubber materials are applied to the cored bar as a plurality of layers in a cylindrical shape. It is characterized by doing.

A plurality of types of unvulcanized rubber materials supplied by a plurality of extruders are laminated on a core metal into a plurality of cylindrical layers by a multilayer extrusion crosshead die. By using a plurality of rubber layers, it is possible to impart specific properties such as conductivity and elasticity to the surface layer, the underlayer, etc., depending on the application of the rubber roller. Also, even if there are multiple layers,
Since the thickness of the rubber layer is changed at the same rate, only the surface layer does not become thin as in the case of polishing and grinding, and the characteristics of the surface layer are not impaired.

According to a sixth aspect of the present invention, in the method for producing a rubber roller, the unvulcanized rubber material contains 100 parts by weight of a rubber material and one of fillers such as silica, calcium carbonate, magnesium carbonate or the like or a combination thereof. The composition is characterized by being blended in an amount of 200 parts by weight to 200 parts by weight.

As the rubber material, in addition to NBR and SBR,
Rubber such as epichlorohydrin and ethylene propylene rubber that is commonly used as a charging roller is used.As a filler such as calcium carbonate, the surface of the rubber roller to be molded is made smooth, and chemical resistance, tensile strength, and abrasion resistance are also used. It is used to reinforce properties such as talc, light calcium carbonate, heavy calcium carbonate,
Light magnesium carbonate, heavy magnesium carbonate, etc., or mixtures thereof are also used.

When the amount of these fillers is less than 50 parts by weight, the skin of the outer peripheral surface of the rubber roller is deteriorated, and when the amount of these fillers exceeds 200 parts by weight, the fluidity of the unvulcanized rubber material is deteriorated and molding is possible. Temperature is high, extrusion pressure is high,
Extrusion becomes difficult.

According to a seventh aspect of the present invention, there is provided a method for manufacturing a rubber roller, wherein the rubber roller coated with the unvulcanized rubber material extruded from the die nozzle is a roller take-up means for taking out at a predetermined speed, and the tip of the core metal in the moving direction is used. A clamp for detachably supporting the tip of the core is moved by the drive means in synchronization with the moving speed of the core metal, and a predetermined buffer means is provided between the drive means and the tip of the core metal. It is characterized by

The tip end of the rubber roller coated with the unvulcanized rubber material is clamped, and is picked up by a driving means such as a servomotor at a speed synchronized with the feeding speed. That is, the feeding speed is changed such that one end portion of the core metal is fast, the central portion is slow, and the other end portion is fast. However, since this change directly affects the shape of the rubber roller, it is necessary to control to a predetermined speed. There is. Further, by inserting some cushioning means such as an air cylinder between the clamp and the driving means, it is possible to eliminate a slight difference between the take-up speed of the driving means and the feeding speed of the cored bar.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Each embodiment of a method for manufacturing a rubber roller according to the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view illustrating a state in which a core metal and an unvulcanized rubber material are supplied to a crosshead die and the core metal is coated with the unvulcanized rubber material. FIG. 2 is a plan view showing an outline of the crosshead extrusion device, and FIG. 3 shows an outline of the shape (thickness) of the unvulcanized rubber material such as a die swell in the die nozzle of the crosshead die and the roller take-up means.

First, referring to FIG. 2, the crosshead extrusion device 6
The outline of the step of applying the unvulcanized rubber material to the core metal 1 according to 2 will be described. The crosshead die 4 is attached to the tip of an extruder 42 equipped with driving means (not shown), unvulcanized rubber material supplying means, etc.
1 is attached. The unvulcanized rubber material is fed to the crosshead die 41 (details will be described later) in the direction of arrow x by the extruder 42.
Is extruded almost in the center. This crosshead die 4
The core metal 1 is supplied and moved in a direction (arrow x ′) intersecting the unvulcanized rubber material supply direction (arrow x). The cored bar 1 is prepared in the cored bar feeding step 2 with its length direction oriented in the feeding direction (arrow x ′), and at the predetermined speed by the cored bar feeding step 3,
It is sent to the crosshead die 41. The core metal 1 is coated with an unvulcanized rubber material in the vicinity of the exit of the crosshead die 41, and is extruded from the die nozzle 43.
Sent to. In the roller treatment step 5, the unvulcanized rubber layer continuously adhered to the core metal 1 is cut and moved to the vulcanization step to be vulcanized and finished. The preparation process and the vulcanization process of the core metal 1 are not shown.

Next, the flow of the core metal 1 and the unvulcanized rubber material 6 in and around the crosshead die 41 will be described in more detail with reference to FIG. 1 (enlarged sectional view of the circle A in FIG. 2). The extruder 42 (see FIG. 1) is provided with a cylinder (not shown) surrounding the outer circumference of a screw 44 rotated by a driving means (not shown), and a breaker 4 is provided at the tip thereof.
6, adapter 47 is attached, and further this adapter 4
A cross head die 41 is attached to the tip of 7.

After preheating the extruder 42 to a predetermined temperature, the unvulcanized rubber material 6 (indicated by a dot group) is supplied from a hopper (not shown) while rotating the screw 44. The unvulcanized rubber material 6 is heated and kneaded, and the screw 4
4 is sent in the direction of the arrow x by means of 4, and is pushed out to the unvulcanized rubber supply port 50 of the crosshead die 41 via the breaker 46 and the adapter 47.

The cross head die 41 includes a head 53, a core body 52, and a nipple 51. The head 53 is tubular and is connected to the tip of the adapter 47, and supports the core body 52 of the tubular crosshead die 41 into which the nipple 51 is fitted. The nipple 51 is provided with a cored bar guide path 57 inside, and the cored bar guide path 57 penetrates from the cored bar supply port 60 to the vicinity of the die nozzle 43 to guide the cored bar 1. The head 53 is provided with a die nozzle 43 at the tip of the core moving direction, and a rubber flow path 56 is provided between the die 53 and the core body 52 to supply the unvulcanized rubber material 6 supplied from the unvulcanized rubber supply port 50. To the die nozzle 43.

Next, the step of depositing the unvulcanized rubber material 6 on the core metal 1 by the cross head die 41 will be described. Core metal 1 prepared in core metal feeding step 3 (see FIG. 2)
Is continuously fed to the cored bar guide path 57 through the cored bar feed port 60 by the cored bar feed roller 4 whose feed speed is adjustable, and the cored bar 1 ″ following the trailing end of the preceding cored bar 1 ′. The front end of the core metal 1 ′ is always in contact with the front end of the core metal 1 ′ and the front end of the core metal 1 ″ that follows, so that the unvulcanized rubber material 6 is kept between them. The core metal 1 does not invade and the feed speed is stable. The feeding speed of the cored bar is controlled by a feeding means (for example, a cored bar feed roller) which is programmed in advance with a predetermined speed of each part of the cored bar 1 extending from one end to the center and the other end.

On the other hand, the unvulcanized rubber material 6 that has been heated and kneaded is supplied from the unvulcanized rubber supply port 50 to the rubber flow path 56 and extruded to the die nozzle 43. In the vicinity of the die nozzle 43, the unvulcanized rubber material 6 is applied to the outer periphery of the core metal 1 that is continuously fed, and the die nozzle 43
Is fed out and becomes an unvulcanized rubber roller. This unvulcanized rubber roller is vulcanized and finished to be used as a transfer roller or the like.

Next, referring to FIG. 3, the change in the thickness of the unvulcanized rubber material deposited by the movement of the core metal 1 and the roller take-up means 61 will be described. FIG. 3 (a) is a portion indicated by circle B in FIG. FIG. 3B is an enlarged view, and FIG. 3B is a partially enlarged view of a circle C in FIG. FIG. 3A shows a change in rubber thickness of an unvulcanized rubber roller extruded from the die nozzle 43 and a tip of the unvulcanized rubber roller (core 1 ′) supported by the clamp 54 of the roller take-up means 61. A method of pulling by the pulling drive means 59 via the buffer means 58 will be described.

First, as shown in the enlarged view of FIG.
At the position of the die nozzle 43, the core metal 1 ′ is extruded by being coated with the unvulcanized rubber material 6 having the thickness d ″. When the core metal 1 ′ is extruded from the die nozzle 43, the unvulcanized material which has been pressurized is pressed. The rubber material 6 is opened and bulges to form a so-called die swell 10, and the thickness of the unvulcanized rubber material 6 increases to d '. In this state, the moving speed of the core metal 1'is set to the crosshead die 41 (see FIG. Reference), the thickness d of the unvulcanized rubber material adhered to the fed core metal 1 ′ is set to be greater than the thickness d ′ of the die swell 10 by increasing the discharge speed of the unvulcanized rubber material 6. Thin, and crosshead die 4
It is also possible to make it thinner than the thickness d ″ of the unvulcanized rubber material in No. 1. By changing the feed rate of the core metal 1 while keeping the amount of extrusion from the unvulcanized rubber supply port 50 constant. The thickness d of the last unvulcanized rubber material can be changed.

As shown in FIG. 3A, the roller take-up means 6
1 is a clamp 54, a buffer means 58, a take-up drive means 59.
With. The tip of the unvulcanized rubber roller (core metal 1 ') extruded from the die nozzle 43 in the moving direction is clamped 54
Supports detachably. The clamp 54 is connected to the take-up drive means 59 via the buffer means 58, and takes in the unvulcanized rubber roller (core bar 1 ') in synchronization with the moving speed of the subsequent core bar 1 ". 59 is driven by, for example, a servomotor that is synchronized with the feeding speed of the core metal, and the buffering means 58 is, for example, an air cylinder, and the take-up speed of the take-up driving means 59 and the feeding speed of the core metal are small. This difference is also absorbed so as not to affect the predetermined moving speed of the subsequent core metal 1 ″.

Further, when the rear end of the unvulcanized rubber roller (core metal 1 ') reaches the position of the cutter 55, the cutter 55 is actuated to move the unvulcanized rubber roller to the succeeding rubber roller (core). The gold 1 ") is separated and transferred to the next step such as the vulcanization step.

A method of manufacturing a rubber roller having a cored bar and molded in a crown shape by using such a crosshead extrusion device 62 (FIG. 2) will be described with reference to Examples and Comparative Examples.

[Example 1] Table 1 shows the composition of the unvulcanized rubber material used.

[Table 1] Rubber material (epichlorohydrin rubber) = 100 parts by weight Filler (light calcium carbonate) = 100 parts by weight carbon (MT) = 25 parts by weight Processing aid = 9 parts by weight Vulcanizing agent (sulfur) = 6.5 parts by weight Using a core metal 1 having an outer diameter of 5 mmφ and a length of 250 mm, as a crosshead extrusion device, a 40 mm extruder manufactured by Mitsuba Seisakusho and a crosshead die having an inner diameter of a die nozzle of 7.1 mmφ are used. Using. The result of measuring the change of the outer diameter of the rubber roller by changing the moving speed of the core metal 1 by setting the extrusion speed (extrusion amount per unit time) of the unvulcanized rubber material by the extruder 42 (FIG. 2) to a predetermined speed. Is shown in FIG. 4 (when molded into a crown shape). 4A shows the speed (moving speed) at which each position (portion) of the core metal 1 is pushed out from the die nozzle 43 by changing the moving speed in one core metal.
In (b), the outer diameter of each position of the rubber roller, which changes depending on the moving speed of the core metal 1, is shown.

At both ends of the cored bar 1 (positions of the cored bar positions 0 and 250), the feeding speed was 2.4 mm / s, and the outer diameter of the rubber roller at this position was 6.94 mm. When the feed speed is gradually reduced toward the central portion to 2.3 mm / s at the central portion (core bar position: 125), the outer diameter of the rubber roller gradually increases and the central portion (core bar position: In 125), it becomes 7.0 mm, and a gentle crown shape is formed. Of course, it is also possible to increase the feeding speed at the central portion to form a gentle drum shape, or to gradually increase the feeding speed from one end to the other end to form a tapered rubber roller.

In this embodiment, as shown in FIG. 1, the trailing end of the leading mandrel 'is moved by pushing the trailing end of the leading mandrel' by the trailing mandrel 1 ". The core metal 1'is always in contact with the tip of the core metal so that the unvulcanized rubber material does not enter between them, and the leading core metal 1'is the succeeding core metal 1 ".
A rubber roller having an outer diameter changed corresponding to this moving speed was formed in synchronism with the change of the moving speed.

Example 2 An unvulcanized rubber material having the same composition as in Example 1 (also referred to as composition A) and the composition A of Example 1 were used.
An unvulcanized rubber material (also referred to as composition B) in which the rubber material of NBR was NBR was prepared, and a multi-layer extrusion crosshead die was used as a crosshead extrusion device instead of the crosshead die, and the results were obtained as in Example 1. An unvulcanized rubber roller was formed under the same conditions. A rubber roller having two rubber layers having the composition A as the outer peripheral surface and the composition B as the inner side and having the crown shape with the outer diameter similar to that in Example 1 was obtained. A vulcanized rubber roller is vulcanized in a heating furnace or the like to finish it to a transfer roller or the like.

[Comparative Example 1] The same composition A as shown in Table 1 as in Example 1 was used, the same crosshead extruder as in Example 1 was used, and the extrusion speed of the unvulcanized rubber material was also as in Example 1. Same as The feeding speed of the core metal was kept constant at 2.34 mm / s. The outer diameter of the extruded rubber roller is 6.9 over the entire length.
It became almost uniform at 8 mm.

[Comparative Example 2] In composition A used in Example 1, the amount of the filler was varied, the same crosshead extruder as in Example 1 was used, and unvulcanized under the same production conditions. Rubber rollers were manufactured. When the filler (light calcium carbonate) is 30 parts by weight, the resulting unvulcanized rubber roller has
A small waveform was generated on the outer peripheral surface, and when the amount of the filler was 250 parts by weight, the load of the extruder was large and the extrusion amount was not stable, and the outer diameter of the obtained rubber roller was unstable.

[0042]

As is apparent from the above description,
The rubber roller manufacturing method of the present invention has the following effects.

According to the manufacturing method of the first aspect, the outer diameter of the rubber roller is changed by changing the moving speed of the core metal in the die nozzle of the crosshead extrusion device depending on the portion in the length direction of the core metal. Can be made. Since the core metal can be made thin at the fast moving part and thick at the slow moving part, it is possible to change the core metal feed speed from the crown shape, the hourglass shape, the taper shape, etc. which were conventionally formed by polishing or dies. It can be easily built.

According to a second aspect of the present invention, a crosshead extrusion device is used, and the feeding speed of the cored bar in the die nozzle is set to be high at one end of the cored bar and gradually reduced toward the central part, and further, By gradually increasing the speed from the center to the other end, it is possible to easily form a rubber roller having a crown-shaped outer peripheral shape.

In the manufacturing method according to the third aspect, the leading end of the succeeding mandrel is always brought into contact with the leading end of the leading mandrel fed into the crosshead die, so that no gap is generated between them, and Since the unvulcanized rubber material does not enter the
Since the moving speed of the succeeding cored bar can be accurately transmitted to the preceding cored bar, a predetermined outer diameter and shape can be formed in the rubber roller.

In the manufacturing method according to the fourth aspect, by making the feeding speed of the cored bar faster than the moving speed of the unvulcanized rubber material passing through the die nozzle, small wrinkles due to die swell do not occur, and The thickness of the unvulcanized rubber material can also be applied thinner than when it passes through the die nozzle.

In the manufacturing method according to the fifth aspect, a plurality of types of unvulcanized rubber materials are simultaneously applied to a cored bar in a cylindrical shape, and the feed rate of the cored bar is changed to make the thickness of each layer uniform. It can be changed in proportion. As a result, as in the case of forming a crown shape by polishing, the thickness of the outermost rubber layer does not change significantly, and each layer is changed uniformly,
A crown shape or the like can be formed without changing the characteristics (conductivity, elasticity, etc.) of each layer.

In the manufacturing method according to the sixth aspect, the unvulcanized rubber material is blended with 100 parts by weight of the rubber material and 50 to 200 parts by weight of the filler, so that the skin of the outer peripheral surface of the rubber roller is good. In addition to the above, stable extrusion can be performed at a relatively low processing temperature and a low extrusion pressure.

According to a seventh aspect of the present invention, in the method of manufacturing a rubber roller, the feeding speed of the cored bar is changed such that one end of the cored bar is faster, the central part is slower, and the other end is faster. Although the shape is formed, in this case, since the feeding speed is influenced by the moving speed of the preceding rubber roller, the tip of the rubber roller coated with the unvulcanized rubber material is clamped and, for example, a servo motor is used. It is picked up by the drive means at a rate that is in tune with the varying feed rate. Furthermore, by inserting a buffering means such as an air cylinder between the clamp supporting the rubber roller and the driving means, a slight difference between the take-up speed of the driving means and the feeding speed of the cored bar to the crosshead die is eliminated. be able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a part of an extruder and a crosshead die for explaining a state in which an unvulcanized rubber material 6 is adhered to a core metal 1 by a crosshead die in a method for manufacturing a rubber roller of the present invention. (A partially enlarged view of FIG. 2 circle A).

FIG. 2 is a plan view (partially omitted) showing a layout of a crosshead extrusion device used in the method for manufacturing a rubber roller of the present invention.

3 is a partially enlarged view of a circle B of FIG. 1, FIG. 3 (a) shows a cross section of a die nozzle 43 provided with a roller take-up means 61, and FIG. 3 (b) shows a circle C of FIG. 3 (a). FIG.

4A and 4B are diagrams showing a moving speed of a core metal 1 and an outer diameter of a rubber roller in Example 1, FIG. 4A shows a moving speed at each position of the core metal, and FIG. 4 (a) shows the outer diameter of the rubber roller corresponding to each position.

[Explanation of symbols]

1: Core metal 3: Core bar feeding process 4: Core feed roller 5: Roller processing process 6: Unvulcanized rubber material 7: Take-up roller 10: Dice L 11: Adhered rubber 41: Crosshead die 42: Extruder 43: Die nozzle 50: Unvulcanized rubber supply port 57: Core metal guideway 58: Buffer means 59: Take-up drive means 60: Core bar supply port 61: Roller take-up means 62: Crosshead extrusion device

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Claims (7)

[Claims] 1. An unvulcanized rubber material is supplied from an unvulcanized rubber supply port at a substantially central portion of a crosshead die of a crosshead extrusion device, and a core metal is supplied from a core metal insertion port of the crosshead die. The unvulcanized rubber material is fed into a guide passage, and the unvulcanized rubber material is fed into a rubber flow path that is provided along the core metal guide passage and intersects the core metal guide passage near the die nozzle, and the unvulcanized rubber is attached to the core metal. A method of manufacturing a rubber roller that feeds an unvulcanized rubber roller from a die nozzle while coating a material in a cylindrical shape, wherein the moving speed of the core metal in the die nozzle is one end in the length direction of the core metal, a central part, A method of manufacturing a rubber roller, characterized in that the outer diameter of the unvulcanized rubber material which is cylindrically adhered to the core metal is changed along the longitudinal direction by changing the diameter according to the other end portion or the like. 2. The moving speed of the cored bar in the die nozzle is set to be high at one end of the cored bar, gradually slowed down toward the central part, and further gradually increased from the central part toward the other end. The method of manufacturing a rubber roller according to claim 1, wherein the outer peripheral shape of the rubber roller is molded into a crown shape. 3. The following mandrel is attached in the advancing direction such that the leading end of the succeeding mandrel is always in contact with the trailing end of the preceding mandrel coated with the unvulcanized rubber material and extruded from the die nozzle. The method for manufacturing a rubber roller according to claim 1 or 2, which is biased. 4. The method of manufacturing a rubber roller according to claim 1, wherein the moving speed of the core metal is set higher than the discharging speed of the unvulcanized rubber material passing through the die nozzle. 5. A multi-layer extrusion crosshead die is used as the crosshead die, whereby a plurality of types of unvulcanized rubber materials are applied to the core metal in a cylindrical shape of a plurality of layers. A method for manufacturing a rubber roller according to claim 1. 6. The unvulcanized rubber material is a rubber material 100.
A composition comprising 50 parts by weight to 200 parts by weight of any one of fillers such as silica, calcium carbonate and magnesium carbonate or a combination thereof in parts by weight.
6. The method for manufacturing a rubber roller according to any one of 5 above. 7. A clamp for detachably supporting the tip of the tip of the core in the moving direction as a roller pulling means for pulling a rubber roller coated with the unvulcanized rubber material extruded from the die nozzle at a predetermined speed. Is moved in synchronization with the moving speed of the core metal by the driving means,
7. The method of manufacturing a rubber roller according to claim 1, wherein a predetermined cushioning means is provided between the driving means and the tip of the core metal.