JP6790466B2 - Rubber extruder - Google Patents

Description

The present invention relates to a rubber extruder for kneading and extruding unvulcanized rubber.

As a rubber extruder for kneading and extruding unvulcanized rubber, a rubber extruder having a screw shaft is known. In a conventional rubber extruder having a screw shaft, unvulcanized rubber charged from a charging port is kneaded with a screw shaft and discharged from a discharge port.

In the extrusion molding of unvulcanized rubber by such a rubber extruder, the unvulcanized rubber has voids in the unvulcanized rubber due to the entrainment of air at the time of charging, the volatile component gas generated in the rubber extruder, and the like. In some cases. The voids in the unvulcanized rubber have caused breakage of the extruded product and damage of the final product.

Therefore, Patent Document 1 below proposes a rubber extruder in which a degassing portion is provided between the first and second screw portions and the air and gas in the unvulcanized rubber are sucked from the degassing portion.

Japanese Unexamined Patent Publication No. 2008-302660

A general rubber extruder has a mesh strainer for removing foreign matter in unvulcanized rubber. This is because foreign matter in the unvulcanized rubber also causes breakage of the extruded product and damage of the final product, as in the case of voids in the unvulcanized rubber. Such a strainer is usually arranged on the downstream side of the screw shaft of the rubber extruder.

In the rubber extruder of Patent Document 1, for example, when a strainer is arranged in the screw head portion located on the downstream side of the first and second screw portions, unvulcanized rubber in which air is sucked in the degassing portion. However, it is divided by the strainer on the downstream side and then rejoined. Therefore, in the rubber extruder of Patent Document 1, there is a problem that the unvulcanized rubber entrains air again when passing through the strainer, and still creates voids in the unvulcanized rubber.

The present invention has been devised in view of the above circumstances, and is a rubber extrusion capable of efficiently sucking air and gas in unvulcanized rubber based on providing a degassing portion on the downstream side of the strainer. Its main purpose is to provide an opportunity.

The present invention is a rubber extruder for kneading and extruding unvulcanized rubber, and sucks a mesh-like strainer for removing foreign substances in the unvulcanized rubber and air in the unvulcanized rubber. The degassing portion is provided on the downstream side of the strainer and adjacent to the strainer.

In the rubber extruder according to the present invention, it is desirable that the rubber extruder has a screw shaft for extruding the unvulcanized rubber, and the strainer and the degassing portion are provided on the downstream side of the screw shaft.

In the rubber extruder according to the present invention, in order to discharge the unvulcanized rubber which is arranged on the downstream side of the first extrusion portion and the first extrusion portion having an input port for charging the unvulcanized rubber. The first extruded portion includes a second extruded portion having a discharge port, and a connecting portion for connecting the first extruded portion and the second extruded portion so that the unvulcanized rubber can communicate with each other. It has a first screw shaft for extruding the vulcanized rubber toward the second extrusion portion, and the second extrusion portion is separate from the first screw shaft for extruding the unvulcanized rubber to the discharge port. It is desirable to have the second screw shaft of the above, and the connecting portion has the strainer and the degassing portion.

In the rubber extruder according to the present invention, it is desirable that the second extrusion portion is not provided with a strainer for removing foreign substances in the unvulcanized rubber.

In the rubber extruder according to the present invention, it is desirable that the second extrusion section is larger than the first extrusion section.

In the rubber extruder according to the present invention, it is desirable that the degassing portion is connected to a vacuum device.

The rubber extruder of the present invention has a mesh strainer for removing foreign matter in the unvulcanized rubber and a degassing part for sucking air in the unvulcanized rubber. Such a rubber extruder can remove foreign substances in the unvulcanized rubber, and can also suck air caught in the unvulcanized rubber and gas generated in the unvulcanized rubber, and is homogeneous. Unvulcanized rubber can be extruded.

The degassing portion of the rubber extruder of the present invention is provided on the downstream side of the strainer and adjacent to the strainer. In such a degassing portion, since the unvulcanized rubber separated by the strainer can have a negative pressure in the vicinity of the portion where the unvulcanized rubber merges again, the air and gas in the unvulcanized rubber can be efficiently sucked.

It is sectional drawing which shows one Embodiment of the rubber extruder of this invention. It is sectional drawing which shows the other embodiment of the rubber extruder of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing the rubber extruder 1 of the present embodiment. As shown in FIG. 1, the rubber extruder 1 of the present embodiment kneads and extrudes unvulcanized rubber G. It is desirable that the rubber extruder 1 has a casing 2 having a substantially cylindrical shape and a screw shaft 3 housed inside the casing 2.

The casing 2 has, for example, a closed portion 2a closed on one end side in the longitudinal direction, an open portion 2b opened on the other end side, and a side surface portion 2c connecting the closed portion 2a and the open portion 2b. ing. It is desirable that a charging port 4 for charging the unvulcanized rubber G is provided on one end side of the side surface portion 2c. That is, the unvulcanized rubber G is charged into the casing 2 from the charging port 4 on one end side and pushed out from the open portion 2b on the other end side. The cross-sectional area of the open portion 2b of the present embodiment is smaller than the cross-sectional area of the side surface portion 2c. Such an open portion 2b can densely extrude the unvulcanized rubber G.

The screw shaft 3 is for extruding the unvulcanized rubber G in the casing 2. The screw shaft 3 of the present embodiment includes a shaft main body 3A and a spiral blade 3B protruding outward in the radial direction of the screw shaft 3 from the shaft main body 3A.

It is desirable that the shaft body 3A is linearly arranged along the longitudinal direction of the casing 2. The spiral blade 3B is formed continuously in the circumferential direction while being displaced in the axial direction of the screw shaft 3, for example. Such a spiral blade 3B can extrude the unvulcanized rubber G in the casing 2 from the closed portion 2a toward the open portion 2b while kneading. It is desirable that the screw shaft 3 is driven by a drive device M arranged outside the closed portion 2a side of the casing 2.

The rubber extruder 1 of the present embodiment is for sucking the net-like strainer 5 for removing foreign matter in the unvulcanized rubber G and the air in the unvulcanized rubber G in the vicinity of the open portion 2b of the casing 2. It has a degassing part 6 of the above. It is desirable that the strainer 5 and the degassing portion 6 are provided on the downstream side of the screw shaft 3. Such a rubber extruder 1 can remove foreign substances in the unvulcanized rubber G, and can suck the air caught in the unvulcanized rubber G and the gas generated in the unvulcanized rubber G. It is possible to extrude a homogeneous unvulcanized rubber G.

The strainer 5 is preferably made of metal. The strainer 5 is preferably formed of a wire mesh having a mesh size of 0.1 to 1.0 mm. The strainer 5 can divide the unvulcanized rubber G when the unvulcanized rubber G passes through the strainer 5 and promote the shear heat generation of the unvulcanized rubber G. Such a strainer 5 can promote the gasification of the volatile components in the unvulcanized rubber G by the shear heat generation, and can form a more uniform unvulcanized rubber G. The strainer 5 may be formed of, for example, a punching metal.

It is desirable that the degassing unit 6 is connected to the vacuum device P. Such a degassing unit 6 can create a negative pressure inside the rubber extruder 1.

It is desirable that the degassing portion 6 is provided on the downstream side of the strainer 5 and adjacent to the strainer 5. Since such a degassing unit 6 can create a negative pressure in the vicinity of the portion where the unvulcanized rubber G separated by the strainer 5 merges again, the air entrained when the unvulcanized rubber G merges can be efficiently sucked. can do.

In the present embodiment, the upstream side of the degassing portion 6 is sealed by the unvulcanized rubber G pressed against the strainer 5, and the downstream side of the degassing portion 6 becomes dense as the cross-sectional area of the opening portion 2b is reduced. It is sealed with unvulcanized rubber G. Therefore, the inside of the rubber extruder 1 near the degassing portion 6 can be a small space in which both ends are sealed by the unvulcanized rubber G. As a result, the degassing unit 6 can efficiently create a negative pressure in the vicinity of the portion where the unvulcanized rubber G separated by the strainer 5 rejoins, and the air and gas in the unvulcanized rubber G can be made more reliable. Can be sucked into.

FIG. 2 is a cross-sectional view showing the rubber extruder 10 of another embodiment. As shown in FIG. 2, the rubber extruder 10 of this embodiment includes a first extrusion section 11, a second extrusion section 12 arranged on the downstream side of the first extrusion section 11, and a first extrusion section 11. It includes a connecting portion 13 for connecting the second extruded portion 12 so that the unvulcanized rubber G can communicate with each other.

It is desirable that the first extrusion portion 11 has a charging port 14 for charging the unvulcanized rubber G. It is desirable that the second extrusion portion 12 has a discharge port 15 for discharging the unvulcanized rubber G. That is, the unvulcanized rubber G is charged into the rubber extruder 10 from the charging port 14 of the first extrusion section 11, passes through the first extrusion section 11, the connecting section 13, and the second extrusion section 12, and is passed through the second extrusion section. It is extruded from the discharge port 15 of 12.

In this embodiment, the gear pump 16 is provided on the downstream side of the rubber extruder 10. The gear pump 16 is preferably connected to the discharge port 15 of the second extrusion section 12. Therefore, the unvulcanized rubber G discharged from the discharge port 15 is supplied to the gear pump 16. In the gear pump 16, for example, unvulcanized rubber G is formed into a band-shaped rubber.

It is desirable that the first extruded portion 11 has a substantially cylindrical first casing 17 and a first screw shaft 18 housed inside the first casing 17.

The first casing 17 includes, for example, a first closed portion 17a closed on one end side in the longitudinal direction, a first open portion 17b opened on the other end side, a first closed portion 17a, and a first open portion 17b. It has a first side surface portion 17c for connecting the above. It is desirable that the input port 14 is provided on one end side of the first side surface portion 17c. Further, it is desirable that the first open portion 17b is connected to the connecting portion 13. That is, the unvulcanized rubber G is charged into the first casing 17 from the charging port 14 on one end side, and is pushed out to the connecting portion 13 from the first opening portion 17b on the other end side.

It is desirable that the first screw shaft 18 is driven by the first driving device M1 arranged outside the first closing portion 17a side of the first casing 17. Such a first screw shaft 18 extrudes the unvulcanized rubber G toward the second extrusion portion 12.

It is desirable that the second extrusion portion 12 has a second casing 19 having a substantially cylindrical shape and a second screw shaft 20 housed inside the second casing 19.

The second casing 19 includes, for example, a second closed portion 19a closed on one end side in the longitudinal direction, a second open portion 19b opened on the other end side, a second closed portion 19a, and a second open portion 19b. It has a second side surface portion 19c that connects the two. It is desirable that the connecting portion 13 is connected to one end side of the second side surface portion 19c. Further, it is desirable that the second opening portion 19b is provided with a discharge port 15. That is, the unvulcanized rubber G extruded from the first extruded portion 11 is thrown into the second casing 19 from the connecting portion 13 on one end side, and is extruded to the gear pump 16 from the discharge port 15 on the other end side.

In the second casing 19 of this embodiment, the cross-sectional area of the second side surface portion 19c is larger than the cross-sectional area of the first side surface portion 17c of the first casing 17. That is, it is desirable that the second extruded portion 12 is larger than the first extruded portion 11. Such a second extrusion unit 12 can smoothly extrude the unvulcanized rubber G into the discharge port 15.

The second screw shaft 20 is different from the first screw shaft 18, and is driven by the second drive device M2 arranged outside the second closing portion 19a side of the second casing 19. desirable. Since such a second screw shaft 20 can be rotated at a speed different from that of the first screw shaft 18, the unvulcanized rubber G can be smoothly pushed out by the discharge port 15.

The connecting portion 13 connects, for example, the first open portion 17b of the first extrusion portion 11 and the second side surface portion 19c of the second extrusion portion 12 so that the unvulcanized rubber G can communicate with each other. The connecting portion 13 of this embodiment has a mesh-like strainer 21 for removing foreign matter in the unvulcanized rubber G and a degassing portion 22 for sucking air in the rubber extruder 10. ..

The strainer 21 is preferably made of metal. The strainer 21 is preferably formed of a wire mesh having a mesh size of 0.1 to 1.0 mm. When the unvulcanized rubber G passes through the strainer 21, the strainer 21 can divide the unvulcanized rubber G and promote the shear heat generation of the unvulcanized rubber G.

It is desirable that the degassing unit 22 is connected to the vacuum device P1. Such a degassing portion 22 can create a negative pressure inside the connecting portion 13.

It is desirable that the degassing portion 22 is provided on the downstream side of the strainer 21 and adjacent to the strainer 21. Since such a degassing portion 22 can create a negative pressure in the vicinity of the portion where the unvulcanized rubber G separated by the strainer 21 rejoins, the air and gas in the unvulcanized rubber G can be efficiently sucked. it can.

In this embodiment, the upstream side of the degassing portion 22 is sealed by the unvulcanized rubber G pressed against the strainer 21, and the downstream side of the degassing portion 22 is the connecting portion between the connecting portion 13 and the second extruded portion 12. It is sealed by the unvulcanized rubber G in the vicinity. Therefore, the inside of the connecting portion 13 can be a small space in which both ends are sealed with unvulcanized rubber G. As a result, the degassing unit 22 can efficiently create a negative pressure in the vicinity of the portion where the unvulcanized rubber G separated by the strainer 21 rejoins, and the air and gas in the unvulcanized rubber G can be made more reliable. Can be sucked into.

In this embodiment, the second extrusion portion 12 located on the downstream side of the degassing portion 22 is not provided with a strainer for removing foreign matter in the unvulcanized rubber G. Therefore, the unvulcanized rubber G sucked by air in the degassing unit 22 is extruded from the discharge port 15 without being divided again, so that a more homogeneous unvulcanized rubber G can be extruded.

In the rubber extruder 10 of this embodiment, one first extrusion portion 11 is connected to the second extrusion portion 12 via a connecting portion 13, but for example, two or more first extrusion portions 11 are second. It may be connected to the extrusion section 12. It is desirable that such a rubber extruder 10 has the same number of connecting portions 13 as the first extrusion portion 11, and each connecting portion 13 has a strainer 21 and a degassing portion 22, respectively.

Although the particularly preferable embodiments of the present invention have been described in detail above, the present invention is not limited to the illustrated embodiments and can be modified into various embodiments.

1,10 Rubber extruder 5,21 Strainer 6,22 Degassing part G Unvulcanized rubber

Claims (6)

A rubber extruder for kneading and extruding unvulcanized rubber.
A first extrusion unit having an input port for charging the unvulcanized rubber and a second extrusion unit arranged on the downstream side of the first extrusion unit and having a discharge port for discharging the unvulcanized rubber. And a connecting portion for connecting the first extruded portion and the second extruded portion so that the unvulcanized rubber can communicate with each other.
The connecting portion has a mesh strainer for removing foreign matter in the unvulcanized rubber and a degassing portion for sucking air in the unvulcanized rubber.
The strainer is formed of a wire mesh having a mesh size of 0.1 to 1.0 mm.
A rubber extruder characterized in that the degassing portion is provided on the downstream side of the strainer and adjacent to the strainer.
Before SL strainer and the degassing unit, rubber extruder according to claim 1 provided downstream of the first screw shaft.
Before first extruding unit SL has a first screw shaft for pushing the unvulcanized rubber into the second pushing portion side,
The second pushing portion, the rubber extruder according to claim 1 or 2, have a second screw shaft separate from the first screw axis for extruding unvulcanized rubber to said discharge port.
The rubber extruder according to any one of claims 1 to 3, wherein the second extrusion unit is not provided with a strainer for removing foreign substances in unvulcanized rubber.
The rubber extruder according to any one of claims 1 to 4, wherein the second extrusion section is larger than the first extrusion section. The rubber extruder according to any one of claims 1 to 5, wherein the degassing unit is connected to a vacuum device.

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