JP4624196B2 - Rubber roll manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a rubber roll such as a paper feed roll, a charging roll, a transfer roll, a developing roll, a toner supply roll, and a cleaning roll incorporated in a copying machine or a printer . More specifically , the present invention relates to a method of manufacturing an unvulcanized rubber roller by coating a rubber compound (unvulcanized rubber material) while continuously feeding a core metal using a crosshead extruder. The unvulcanized rubber rubber roller then becomes vulcanized with rubber rolls.

In the manufacturing method of an unvulcanized rubber roll using a general cross head extruder, in the molding in which the rubber compound is coated while continuously feeding the core metal, the extruder head (1) as shown in FIG. The rubber is extruded into a cylindrical shape inside, and the metal core (3) whose position is determined by the metal core guide (4) is fed continuously and intermittently by the metal core feed roll (2). The rubber material (6) is coated on the outer periphery of the core metal . The core-rubber cylindrical integrated body, which is integrally coated and extruded from the tip of the extruder head (7), is separated into rolls one by one by a take-off cutting machine attached to the extruder, and goes to the subsequent process. It is conveyed and vulcanized to form a rubber roll.

Conventionally, as shown in the figure, this take-off cutting machine has a structure in which an extruded mandrel-rubber columnar integral is received by a convex or concave guide pin (8), and the guide pin (8) by utilizing the pushing force of the core (3) retracts at a feed rate of the metal core (3) (a), recessed into a semicircular shape as in Patent Document 1 where the length of one partial roll comes The cutting blade (9) with a clamp clamps the cored bar (3) and moves backward at a speed (b) higher than the cored bar supply speed while holding the roll between the cutting blade (9) and the guide pin (8). It has a mechanism that pulls it apart for one roll.

However, in the rubber material coating molding to the metal core by the crosshead extrusion, the unvulcanized rubber cannot be cut well by the cutting mechanism, or the shrinkage due to the stress release of the rubber material starts immediately after the extrusion, and FIG. As shown, a phenomenon occurs in which the rubber material covered up to the end of the core metal shrinks into a conical trumpet shape or floats from the core metal. These are the main causes of problems such as handling troubles in the subsequent process, for example, attachment / detachment errors due to misalignment, dropping during conveyance due to non-constant dimensions, and a decrease in dimensional accuracy.
JP 2002-248668 A

Therefore , the present invention finds a method of forming a rubber roll by a take-off cutting mechanism in which an unvulcanized rubber material coated on a core bar extruded from a crosshead die does not float off the core bar. The core metal-rubber integrated product extruded from the crosshead die is separated for each roll in a state where the rubber is in close contact with the core metal to the end, and is smoothly and stably conveyed to the subsequent vulcanization process. It aims at providing the manufacturing method of the rubber roll which can be manufactured.

  The object of the present invention is achieved by the following.

That is, the present invention
Pass the core metal through the crosshead die, supply unvulcanized rubber material by an extruder onto the outer periphery of the core metal , extrude the unvulcanized rubber roll , cut the unvulcanized rubber roll into the core metal length, Next, in a method for producing a rubber roller by vulcanization,
Sometimes extruding the unvulcanized rubber roll, when the rubber roller with the metal core front end coming extruded
The end rubber part corresponding to the end part of the metal core is sandwiched between gripping jigs at the front end part of the semi-cylindrical shape , and taken up in synchronization with the supplied metal core ,
When the unvulcanized rubber roller is cut, the end rubber portion corresponding to the end portion of the core metal when the discharged core metal is used as a rubber roll is separated while being sandwiched by a gripping jig at the rear end portion of the semi-cylindrical shape. A method for manufacturing a rubber roll, characterized in that each roll is cut with a cutting blade for use .

As described above, in the method for producing a rubber roll according to the present invention, a jig for picking up a rubber material that has been extruded into a roll take-up mechanism while being sandwiched by a semi-cylindrical jig is provided, and the core from which the semi-cylindrical jig is extruded The rubber core on the outer periphery of the gold is sandwiched up and down and taken in synchronization with the transport speed of the roll, so that the core metal-rubber integrated material extruded from the crosshead die is in close contact with the core to the end. in disconnected every roll, they carry the vulcanization step of smoothly stable post-process, floating defective rubber of the core metal, handling problems, to dramatically improve the defects in manufacturing such Can do. Further, the outer diameter accuracy of the dimensions of the rubber roll according to the present manufacturing method is remarkably improved .

  Hereinafter, the present invention will be described in detail with reference to the drawings.

In the rubber roll manufacturing method of the present invention , a crosshead type extruder capable of continuously coating the rubber compound (6) on the core metal (3) is used. Preferably , a cored bar guide (4) using a cored bar feeding device that intermittently feeds the cored bar (3) to which a primer composed mainly of a resin is partially applied in order to adhere to the rubber part. ) .

The core metal (3) is covered with a rubber compound (6) in a rubber coating area inside the crosshead die (1), and is extruded from a cylindrical die (7) in a roll shape (FIG. 1A). The extruded roll is immediately guided by the guide pin (10) of the take-up device, and at the same time, the tip is sandwiched from above and below by a semi-cylindrical front end gripping tool (11), and is lifted from the core due to rubber contraction. Is prevented (FIG. 1A).

The radius (r) of the gripping jig (11) at the front end of the semi-cylindrical shape is designed to be 5 to 50% smaller than the radius of the extruded roll-shaped rubber, and the length (L) is used as a rubber roll. Designed with a length that does not cover the rubber part. Further, if the shape of the rubber roll facing portion to be sandwiched is a shape having an arc-shaped portion sufficient to sandwich the rubber roll, the outer shape is not limited (left side in FIG. 2) .

The guide pin (10) and the holding jig (11) at the front end of the semi-cylindrical shape slide in accordance with the extrusion speed (a) of the roll, and when the length of one roll comes out, a cutting blade (9 ) And the gripping jig (12) at the rear end of the semi-cylindrical shape, similar to the gripping jig at the front end, to suppress the separation of the rubber part and the contraction of the rear end. At the same time, they are separated at a speed (b) equal to or higher than the core metal supply speed to form one roll (FIG. 1B).

In the semi-cylindrical rear end gripping jig (12) according to the present invention, the semicircular curved surface having a length L sandwiches the end rubber portion of the rubber roll following the conventional semicircular cutting blade (9). The effect is exerted by receiving (Fig. 2 right) .

The roll taken up by the above method is conveyed to a subsequent process , vulcanized or foamed, and formed into a stable quality roll in which the core metal and rubber are in close contact with each other.

  Examples of the present invention will be specifically described below.

(Example)
A metal core bar to be a shaft body was prepared by extruding an iron material into a bar having a diameter of about 6 mm by extrusion molding, cutting it to a length of 258 mm, and then applying chemical plating to the thickness of about 3 μm.

  A hot melt type conductive primer mainly composed of styrene resin was applied to the core bar uniformly at a thickness of about 10 μm except for 14 mm from the end.

The core metal was conveyed to a rubber coating area inside the cross head by a core metal supply device attached to the extruder head and a core metal guide in the cross head die.

The extruder is a uniaxial vent type extruder with a φ60mm screw and has a rubber coating function for the crosshead type core metal , the die diameter of the rubber protrusion is φ10.0mm, and the temperature of the entire head is adjusted to about 40 ° C. It is .

  About 200 g per minute of foamable rubber compound containing EPDM as the main polymer by an extruder and containing carbon black, filler, paraffin softener, various vulcanization accelerators and OBSH (sulfonyl hydrazide) foaming compound The core metal was intermittently supplied at 2.0 m / min.

The roll whose rubber was coated on the outer periphery of the core metal in the coating area was extruded at a roll radius of 4.5 mm at a speed of 2.0 m / min, and was guided by the guide pin of the take-up device.

Immediately after that, it is sandwiched from above and below by a holding jig having a semi-cylindrical shape having a radius of 4.0 mm and a length of 10 mm.

The gripping jig of the roll, guide pin, and front end is retracted in the take-up direction at 2.0 m / min, and when the workpiece length is retracted 258 mm, a semi-circular concave cutting blade having a diameter of 6.1 mm and the front end The gripping jig at the rear end of the same size as the gripping jig of the part was sandwiched from above and below , and immediately after that, it was retracted at 5.0 m / min to separate the workpiece into one. The separated workpiece was transported to the next process, and the guide pin and the single part holding jig repeatedly took the next workpiece.

Work carried to the next step 200 ° C. in a hot air furnace for continuously arranged, foamed vulcanized is made in for 20 minutes.

In the roll manufacturing process formed in this way, the number of defective floats from the rubber core is 0 out of 5000, and the number of defects caused by handling is 0 during the production of 5000. The average of the conventional molding method (comparative example) The defect rate (floating defect as shown in FIG. 4) was 21.5%, and the defect rate was significantly reduced by the method of the present invention.

Further, the standard deviation of the outer diameter value of 5000 rubber rolls produced by this production method is 0.0228, which is significantly improved from 0.0857 in the comparative example (calculated excluding defective products). .

In the comparative example, a rubber roll was manufactured with an apparatus using only a cutting blade shown in FIG.

It is the cross-sectional schematic of the take-up mechanism provided with the clamping jig | tool . It is an end holding jig (front and rear) . It is the cross-sectional schematic of the conventional crosshead extruder and a core metal supply and taking-out mechanism . It is a rubber contraction conceptual diagram at the time of rubber extrusion .

1: Cross head body (extrusion head)
2; Metal core feed roll 3; Metal core (with primer)
4; Metal core guide 5; Rubber extruder 6; Rubber compound (unvulcanized rubber material)
7; Die die (extruder head tip)
8; Guide pin (concave shape)
9: Cutting blade
10 : Guide pin (convex shape)
11: Holding jig 12 at the front end ; Holding jig at the rear end

Claims (1)

Pass the core metal through the crosshead die, supply unvulcanized rubber material by an extruder onto the outer periphery of the core metal , extrude the unvulcanized rubber roll , cut the unvulcanized rubber roll into the core metal length, Next, in a method for producing a rubber roller by vulcanization,
Sometimes extruding the unvulcanized rubber roll, with metal core front end coming extruded, sandwiched core metal end end rubber portion of the corresponding portion when the rubber roll at the front end for gripping jig semicylindrical, is supplied Taking it in sync with the core,
At the time of cutting the unvulcanized rubber roller, the end rubber portion corresponding to the end portion of the core metal when it is made into a rubber roll is sandwiched between the gripping jigs at the rear end portion of the semi-cylindrical shape, A method for producing a rubber roll, wherein the rolls are cut one by one with a cutting blade for cutting .

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