JP2016185684A - Twin-screw vent type extruder and manufacturing method of rubber product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a twin-screw vent type extruder capable of optimally balancing an inflow of an extrusion material to a deaeration chamber and an outflow of the extrusion material from the deaeration chamber even with extrusion material with different material characteristics and dissolving problems such as generation of scorch or heat degradation by accumulation of the extrusion material in the deaeration chamber.SOLUTION: A twin-screw 32 and 34 are arranged with crossing, the first screw 32 in an upstream forms a narrow passage 86 of an extrusion material by a stopping 80 on an upstream part of a crossing part and a transfer part 88 with a constricted shape forming smaller diameter than a maximum diameter of the stopping 80 on an outer peripheral surface of a screw shaft part 74 on the crossing part and a deaeration chamber 98 on an outer peripheral side of the transfer part 88, and further the second screw 34 in downstream arranges a flight part 52 penetrating into a groove space 89 formed on an outer peripheral side of the transfer part and scraping the extrusion material flowed into the transfer part 88 by the flight part 52 of the second screw 34 and forward sending it.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a biaxial vent type extruder having a biaxial screw and a method for producing a rubber product.

Conventionally, as a method for producing rubber products and resin products, a method by injection molding or a method by extrusion molding has been widely performed.
In the injection molding method, an extruded material such as a rubber material or a resin material that has been plasticized and fluidized under heating by the rotation of a screw in an extruder is extruded into the injection chamber of the injection machine, and the charge set in the injection chamber is set. When the extrusion material is charged in an amount, the extrusion by the extruder is stopped, and the material in the injection chamber is injected into the cavity of the molding die by the advancement of the injection plunger to be molded into a predetermined shape to obtain a product.
On the other hand, in a method by extrusion molding, for example, a method of manufacturing a rubber product by extrusion molding, a rubber material is continuously extruded from an extruder and then vulcanized to obtain a product.

  By the way, the extruded material (that is, the molding material) contains a gas component such as air (hereinafter simply referred to as air), or air is entrained in the material when the material is supplied to the extruder. In this case, if the air enters the product, foaming occurs, which deteriorates the product characteristics or causes a product failure.

For example, there is an anti-vibration rubber product as one type of rubber product, and this anti-vibration rubber product is usually manufactured by injection molding. In this anti-vibration rubber product, when air enters the product, As a result, the appearance and spring characteristics are deteriorated.
In addition, there are roll products as OA equipment-related products in rubber products, and when air enters the product during the manufacturing process, these products become bubbles and cause deterioration of appearance and spring characteristics. .

On the other hand, even in products manufactured by extrusion molding, such as rubber hoses as a representative example, since air is generally contained in an unvulcanized extruded product, it is added during vulcanization molding after extrusion. It was necessary to pressure vulcanize, specifically, to put an unvulcanized extruded product inside a steam vulcanizing can and heat vulcanize it under the action of pressure by steam.
This is because, if vulcanized in a non-pressurized state where no pressure is applied, the air contained in the unvulcanized rubber expands and foams.
However, there is a problem that the vulcanization equipment using steam is very expensive to install.
Such a problem can be solved if the air can be sufficiently removed when the extruded material is extruded from the extruder.

Conventionally, a vent type extruder is known as an extruder for removing such air from an extruded material.
As this vent type extruder, a single screw (one axis) type screw is generally used.
In this single-shaft vent type extruder, a vent zone is provided in the middle in the axial direction, a deaeration chamber is formed between the screw and the cylinder in the vent zone, and a vent hole is provided at a corresponding position of the cylinder. The air contained in the extruded material is removed by suction by vacuum suction of the inside of the deaeration chamber through the vent hole.

By the way, in the case of this single screw vent type extruder, the optimum screw shape varies depending on the type and properties of the extruded material.
This point will be specifically described below.
FIG. 8 shows an example of a single screw vent type extruder.
In the figure, 202 is a cylinder of a uniaxial vent type extruder 200 and has an extrusion port 204 at the front end.
206 is a screw rotatably disposed inside the cylinder 202, and is adjacent to a screw shaft portion 208 (hereinafter simply referred to as a shaft portion 208), a flight portion 210 protruding from the shaft portion 208 in a spiral manner, and adjacent to the screw portion 208. And a groove 212 formed between the flight portions 210 and 210.

In the figure, reference numeral 215 denotes a vent zone provided at an intermediate portion in the axial direction. In the vent zone 215, a deaeration chamber 214 is formed between the screw 206 and the cylinder 202. A vent hole 216 that communicates with each other is provided.
The deaeration chamber 214 is evacuated by a vacuum pump through the vent hole 216.
The groove 212a of the screw 206 located in the vent zone 215 is deeper than the other grooves.
The groove space of the groove 212 a forms a part of the deaeration chamber 214.

  The screw 206 is also provided with a weir 218 having the same height as the outer peripheral end of the flight part 210 at an upstream portion adjacent to the vent zone 215, and the extruded material is disposed between the weir 218 and the inner surface of the cylinder 202. A narrow passage 220 is formed to pass through.

  When extruding the extruded material using the extruder 200, the extruded material passes over the weir 218, that is, flows into the deaeration chamber 214 through the narrow passage 220, and the surface area is increased. When 214 is vacuum-sucked through the vent hole 216, air in the extruded material is sucked and removed.

When a rubber material is taken as an example, in the case of a soft rubber material, as shown in FIG. 8A, even when the weir 218 is high (that is, when the narrow passage 220 is narrow (for example, the cylinder 202). Even if the gap between the inner surface and the inner surface is about 0.25 mm), it can be easily overcome to some extent and flow into the deaeration chamber 214. Therefore, the amount of inflow into the deaeration chamber 214 per one screw rotation is large.
On the other hand, at the front end portion of the extruder 200, in the case of a soft rubber material, slipping easily occurs with respect to the rotation of the screw 206, so that the outflow amount from the extrusion port 204 per one rotation of the screw is small.
As a result, in the case of a soft rubber material, the outflow amount from the extrusion port 204 tends to be small with respect to the inflow amount into the deaeration chamber 214. In this case, when the weir 218 is high as described above, it is pushed. The amount of extrusion from the outlet 204 tends to be insufficient.

  In this case, if the weir 218 is lowered to increase the amount of extrusion from the extrusion port 204 and the amount of the rubber material flowing into the vent zone 215, that is, the deaeration chamber 214 is increased, the rubber film when getting over the weir 218 becomes thicker. As a result, the deaeration efficiency is lowered, and the inflow amount of the rubber material into the vent zone 215 and the outflow amount of the rubber material from the vent zone 215 toward the extrusion port 204 (inflow amount with respect to the outflow amount). In many cases, the deaeration chamber 214 is expanded with rubber material, and the vent zone 215 necessary for evacuation cannot be sufficiently secured. The vent hole 216 is blocked and cannot be vacuum degassed, that is, vent up occurs.

On the other hand, in the case of a hard rubber material as shown in FIG. 8B, the rubber material is less likely to slip relative to the screw rotation, so the amount of outflow from the extrusion port 204 per one screw rotation is large. .
On the other hand, when the weir 218 is high, the fluidity of the rubber material is poor, so that the amount of the rubber material flowing over the weir 218 and flowing into the vent zone 215 is small.
Therefore, if the weir 218 is high, the amount of rubber material extruded from the extruder tends to be insufficient.
Therefore, if the height of the weir 218 is lowered, the surface area is likely to be insufficiently increased when the rubber material passes over the weir 218 and flows into the vent zone 215.

  As described above, in the soft rubber material and the hard rubber material, the magnitude relationship between the inflow amount of the rubber material into the vent zone 215, that is, the deaeration chamber 214, and the outflow amount of the rubber material from the deaeration chamber 214 is opposite. It becomes.

Accordingly, the optimum screw shape in the case of a soft rubber material is naturally different from the optimum screw shape in the case of a hard rubber material.
Therefore, the balance between the amount of rubber material flowing into the degassing chamber 214 and the amount of rubber material flowing out of the degassing chamber 214 is optimally balanced while securing the necessary extrusion amount using the same screw. In practice, it has been difficult to do so by using a dedicated screw for each different property of the rubber material.
The case of the rubber material has been taken as an example, but this point is basically the same in the case of the resin material.

Conventionally, a twin screw vent type extruder is also known.
For example, the following patent document 1 discloses an example thereof.
In the thing disclosed in this Patent Document 1, the first extruder and the second extruder are arranged apart from each other in the vertical direction and communicated with each other in a vent chamber (deaeration chamber), and the first extruder is threaded. It is disclosed that the extruded material is cut by the rotation of a cutter to form a pellet, which is supplied to a lower second extruder and extruded by the second extruder.

  On the other hand, the following Patent Document 2 discloses an invention relating to a “two-stage four-shaft vacuum extruder”, in which two extruders are arranged apart from each other in the vertical direction, and an outlet of the upper extruder and Connect the supply port of the lower extruder with a connecting pipe, connect a vacuum device to the connecting pipe, and pull down the material that has been extruded from the upper extruder in the form of a thread and evacuated inside the connecting pipe using a vacuum device. It is disclosed that air bubbles in the material are sucked and removed, and then the thread-like material is supplied to the lower extruder and extruded from the front end of the lower extruder.

  In the case of using two extruders in this way, by adjusting the screw rotation speed between the upstream first extruder and the downstream second extruder, the upstream side first extruder is adjusted. It is considered possible to adjust the balance between the amount of material extruding from the extruder 1 into the deaeration chamber, that is, the amount of inflow, and the amount of material outflow from the deaeration chamber to the second extruder (Patent Literature) 1, Patent Document 2 does not disclose such a point).

However, when the material that has flowed into the degassing chamber from the first extruder does not go into the second extruder well, that is, the material in the degassing chamber smoothly flows out to the second extruder on the downstream side. In this case, there is still a problem that the material gradually accumulates in the deaeration chamber, thereby closing the vent hole and causing vent-up.
Further, there is a problem that the material staying in the deaeration chamber is left in a high temperature state for a long time to cause scorch (in the case of a rubber material) or heat deterioration (in the case of a resin material).

JP 59-123638 A JP 60-124232 A

  The present invention is based on the above circumstances and optimally balances the amount of extruded material flowing into the degassing chamber and the amount of extruded material flowing out of the degassing chamber, even for extruded materials with different properties. It is possible to extrude extruded materials having different properties in the same extruder, and further, a sufficient amount of extrusion and sufficient degassing in the degassing chamber can be performed, and the extruded material is placed in the degassing chamber. The purpose of the present invention is to provide a twin-screw vent type extruder that can solve the problem that the accumulation causes the scorch and thermal deterioration of the material.

  Thus, the first aspect of the present invention relates to a twin-screw vent type extruder, and two-screws are provided so as to overlap each other, and the first screw on the first shaft on the upstream side is located upstream of the intersection. The portion having a weir and forming a narrow passage of the extruded material by the weir, and at the intersection, the delivery portion of the extruded material having a diameter smaller than the outermost diameter of the weir on the outer peripheral surface of the screw shaft portion And a deaeration chamber that is vacuum-sucked through a vent hole is formed on the outer peripheral side of the delivery part, and the second screw on the downstream side is the second screw as viewed in the axial direction of the second screw. The flight part of the screw is arranged close to the first screw at a position where the flight part enters the radially inner side of the first screw from the outer peripheral end of the weir toward the delivery part, The narrow passage of the first screw The extruded material flowing into the delivery section Flip, and said second screw that intersects the receiving pass section are without to advance the feed by scraping at the flight portion.

  According to a second aspect of the present invention, in the first aspect, the extruded material is a rubber material.

  According to a third aspect of the present invention, in any one of the first and second aspects, the delivery portion has a shape having a small diameter from the weir toward the radial center of the second screw in the axial direction of the first screw. It is characterized by being.

  According to a fourth aspect of the present invention, in the third aspect, the delivery portion has a constricted shape in which the diameter is reduced from both ends in the axial direction toward the intermediate portion, and the flight portion of the second screw is formed of the second screw. When viewed in the axial direction, the groove is formed in a groove space formed on the outer peripheral side of the constricted shape.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the delivery portion of the first screw does not have a flight portion.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the narrow passage is composed of a plurality of small grooves formed in an outer peripheral portion of the weir, and the small grooves are in the axial direction of the first screw. On the other hand, it is set as the inclination shape of the shape which transfers to the relative rotation direction of the said extrusion material with respect to this 1st screw as it advances to the said delivery part side of the said cross | intersection part.

  According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the outer periphery of the first screw is provided with a guide portion that increases in diameter toward the weir at an upstream portion adjacent to the weir. .

  According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the first screw and the second screw are each oriented in a horizontal direction.

  According to a ninth aspect of the present invention, in the first screw according to any one of the first to eighth aspects, a portion of the outer peripheral portion on the first screw side rotates in a feeding direction of the extruded material by the first screw. It is characterized by being.

  According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the first screw is rotatably supported at both ends in the axial direction.

  According to an eleventh aspect of the present invention, in any one of the first to tenth aspects, the first screw is shorter than the second screw.

  According to a twelfth aspect of the present invention, in any one of the first to eleventh aspects, the first screw has a larger diameter than the second screw.

  A thirteenth aspect of the present invention relates to a method for manufacturing a rubber product. The biaxial vent type extruder according to any one of the second to twelfth aspects of the present invention is used to inject a rubber material into a mold cavity and vulcanize with the mold. To obtain a rubber product.

  The manufacturing method of claim 14 is a rubber product obtained by extruding a rubber material using the twin-screw vent type extruder according to any one of claims 2 to 12 and vulcanizing the deaerated rubber after extrusion. It is characterized by obtaining.

  The manufacturing method of claim 15 is a method of continuously extruding a rubber material using the twin-screw vent type extruder according to any one of claims 2 to 12 and applying no pressure to a degassed rubber extrudate after extrusion. In this state, the rubber product is vulcanized to obtain a long rubber product.

Effects and effects of the invention

  As described above, in the present invention, the biaxial screws are provided so as to overlap each other, and the first screw on the upstream side is provided with the weir at the upstream portion adjacent to the intersecting portion. In addition to forming a narrow passage for the extruded material, the crossing portion has a delivery portion for the extruded material having a diameter smaller than the outermost diameter of the weir on the outer peripheral surface of the screw shaft portion. The second screw on the downstream side, which forms the air chamber, is such that the flight portion of the second screw faces the delivery portion in the axial direction of the second screw, and the radial direction of the first screw is greater than the outer peripheral end of the weir. A second material which is disposed in the position where it enters inward and close to the first screw, and the extruded material which has flowed into the delivery part through the narrow passage of the first screw intersects the delivery part. Screw is hula Is that without to advance the feed by scraping at the door part.

  According to the present invention, by adjusting the number of rotations (rotational speed) between the first screw on the first shaft on the upstream side and the second screw on the second shaft on the downstream side, The balance between the inflow amount and the outflow amount of the extruded material from the deaeration chamber can be made an optimal balance.

As a result, the amount of extrusion material in the deaeration chamber can be maintained at an appropriate constant amount while ensuring a sufficient amount of extrusion from the extrusion port at the front end of the cylinder. The problem that the deaeration amount varies can be solved, the deaeration amount in the deaeration chamber can be made constant, and the deaeration efficiency can be effectively increased.
In addition, the amount of extruded material flowing into the deaeration chamber (inflow rate) is greater (faster) than the amount of extruding material flowing out of the deaeration chamber (outflow rate). As a result, it is possible to satisfactorily prevent the occurrence of vent-up in which the vent hole is blocked.

Further, even if the inflow amount of the extrusion material into the deaeration chamber and the outflow amount of the extrusion material from the deaeration chamber are set to be balanced, the extrusion material in the deaeration chamber is transferred to the second screw on the downstream side. If it does not go well, there is a risk that the extruded material will accumulate in the deaeration chamber and accumulate, resulting in a problem of vent-up. However, in the present invention, the first portion is intersected with the second screw. A delivery portion for the extruded material having a diameter smaller than the outermost diameter of the weir is provided on the outer peripheral surface of the screw shaft portion of the screw, and the second screw on the downstream side has the flight portion facing the delivery portion. Since the first screw is positioned radially inward from the outer peripheral end, the flight part of the second screw is made the delivery part as much as possible, more specifically, the outer circumference of the screw shaft part constituting the delivery part. Close to the surface Come, can flow out of the extruded material which has flowed into the delivery section from the degassing chamber by scraping it in position flight portion of the second screw is near.
As a result, the extruding material in the deaeration chamber does not satisfactorily bite into the second screw, so that the extruding material can be prevented from staying and accumulating in the deaeration chamber. The vent-up which is blocked by can be prevented even better.

  Furthermore, the delivery of the extruded material from the delivery section to the second screw is performed well, and it is prevented that the extruded material stays and accumulates in the deaeration chamber. Thus, the problem that the deaeration amount in the deaeration chamber becomes insufficient can be solved, and the deaeration quality and the deaeration efficiency can be kept constant and high efficiency.

The present invention is particularly suitable when applied to an extruder for extruding a rubber material as an extrusion material (claim 2).
By applying to such a rubber extruder, scorch due to the retention of the rubber material in the deaeration chamber is prevented, and the burnt rubber is mixed into the regular rubber material and enters the rubber product as it is. Can be solved satisfactorily.
In addition, when applied to a rubber extruder, when the rubber material of the delivery part of the first screw is scraped off by the flight part of the second screw, the rubber material can be pulled and stretched to increase the surface area. As a result, an advantage that the deaeration efficiency can be increased is obtained.

In the present invention, the delivery section can be formed in a shape having a small diameter from the weir to the radial center of the second screw in the axial direction of the first screw.
In this case, the flight part of the second screw can scrape the extruded material in the delivery part better and more effectively prevent the extruded material from accumulating and staying in the deaeration chamber. Will be able to.

  In particular, according to claim 4, the shape of the delivery portion is a constriction shape in which the diameter is reduced from both axial ends toward the intermediate portion, and the flight portion of the second screw enters the groove space formed on the outer peripheral side of the constriction shape. If it is positioned in the open state, the extruding material of the delivery section can be more reliably scraped off at the flight section of the second screw so as to flow out of the deaeration chamber.

In the present invention, the delivery portion of the first screw can be configured not to have a flight portion.
By doing in this way, the 1st screw and the 2nd screw are made to approach more in a delivery part. Specifically, the flight part of the 2nd screw is made from the peripheral end of the above-mentioned weir to the delivery part of the 1st screw. Also, it is possible to approach the position where the first screw enters deeper inward in the radial direction, and the extruded material can be scraped off at the flight portion of the second screw with higher efficiency.

In the present invention, the narrow passage is formed by a plurality of small grooves formed on the outer periphery of the weir, and the small grooves are advanced toward the groove side with respect to the axial direction of the first screw. It can be set as the inclination shape of the shape which transfers to the relative rotation direction of the extrusion material with respect to a 1st screw (Claim 6).
By doing in this way, the extruded material that has just reached the upstream side of the weir can be smoothly guided into the small groove and flow along the small groove, and the extruded material cannot smoothly flow over the weir through the small groove. It is possible to improve the retention just before the weir.

In this case, a guide portion that increases in diameter toward the weir can be provided in an upstream portion adjacent to the weir (Claim 7).
By doing so, the extruded material can be flow-guided toward the small groove on the outer peripheral side of the weir at the guide portion, and it is further effectively improved that the extruded material stays at a position immediately upstream of the weir. Can do.
In this case, the guide portion may have a tapered shape, and the maximum diameter portion may have a shape that is connected to the outer peripheral surface of the weir.

In the present invention, the first screw and the second screw can be arranged in the horizontal direction so as to cross each other (claim 8).
For example, if the first screw on the upstream side is oriented vertically, it is difficult to provide the extrusion material supply port at the optimum position, but if the first screw and the second screw are oriented horizontally, It is easy to arrange the supply port at an appropriate position on the side of the nearby passage, and the workability during the extrusion operation can be improved.

In the present invention, the second screw can be configured such that a portion of the outer peripheral portion on the first screw side rotates in the feed direction of the extruded material by the first screw (claim 9).
In this way, the extruded material that has passed through the narrow passage formed by the weir and has been fed to the delivery portion at the intersection can be satisfactorily pulled in the feeding direction by the rotation of the second screw, As a result, the surface area of the extruded material can be increased to increase the deaeration efficiency.

In the present invention, the upstream first screw can be rotatably supported at both ends in the axial direction, that is, the first screw can be held at both ends.
Usually, the screw is supported so as to be rotatable only at one end in the axial direction, that is, cantilevered in many cases. However, when the first screw is both supported according to claim 10, the first screw has high rigidity. It can support firmly and can prevent favorably that the clearance between the second screw and the second screw will fluctuate due to the centering of the first screw.
In addition, by this, it is possible to maintain an appropriate positional relationship in which the positional relationship between the flight portion of the second screw and the delivery portion of the first screw is set, and the flight of the second screw with respect to the extruded material flowing into the delivery portion. Good scraping by the part can be ensured.

In the present invention, the first screw may be shorter than the second screw (claim 11).
By doing in this way, the rigidity of the 1st screw can be made still higher rigidity, and the core runout of the 1st screw can be prevented still more effectively by that.

Furthermore, this 1st screw can be made larger diameter than a 2nd screw (Claim 12).
Thereby, the rigidity of the first screw can be further increased.

In addition, when the diameter of the first screw is larger than that of the second screw in this way, the radial passage width in the narrow passage is reduced to effectively increase the surface area when the extruded material passes through the passage. By increasing the circumferential length in the rotational direction while increasing the size, the passage area of the entire narrow passage can be secured widely.
Thus, the extruded material can be made to flow effectively into the transfer portion at the intersecting portion, that is, the deaeration chamber, while effectively thinning the extruded material, and the inflow amount can be increased.
Therefore, it is possible to satisfactorily solve the problem that the extrusion amount from the extrusion port at the front end of the cylinder cannot be increased due to the inflow amount of the extrusion material flowing into the deaeration chamber, and the surface area of the extrusion material flowing into the deaeration chamber can be reduced. Increasing the size makes it easy to secure a sufficient amount of extrusion while improving the deaeration efficiency.

  If the diameter of the existing extruder screw incorporated in the molding apparatus, such as an extruder in the injection molding apparatus, is made larger than the current diameter, a large cost is required. However, the first screw is not included in the existing screw. In this case, the extruder of the present invention can be configured using the existing extruder screw as it is, so that the cost of claim 12 can be reduced. An extruder can be built.

  Next, claim 13 relates to a method for manufacturing a rubber product. In this manufacturing method, a rubber material is injected into a cavity of a mold using the biaxial vent type extruder according to any one of claims 2 to 12. And is vulcanized with a molding die to obtain a rubber product. According to the manufacturing method of claim 13, a good rubber product free from bubbles can be manufactured.

  The manufacturing method according to claim 13 can be suitably applied as a method for manufacturing a vibration-proof rubber product or a roll product related to OA equipment, whereby the vibration-proof rubber product or roll product related to OA equipment can be vulcanized. At this time, the phenomenon of foaming by air in the rubber material can be prevented, and a vibration-proof rubber product having good quality without bubbles and a roll product related to OA equipment can be manufactured.

In this case, the extruder can be incorporated in a rubber product vulcanization molding apparatus.
In this case, when the rubber material is supplied to the supply port (input port) of the extruder, the air caught when the screw bites the rubber material or the air previously contained in the rubber material is extruded well. The rubber material can be supplied to the mold in a state where it is removed by a machine and air is sufficiently removed.

  The following claim 14 also relates to a method for producing a rubber product. In this production method, the rubber material is extruded using the twin-screw vent type extruder according to any one of claims 2 to 12, and after the extrusion, A rubber product is obtained by vulcanizing degassed rubber. According to the manufacturing method of claim 14, a good rubber product free of bubbles can be manufactured.

Claim 15 also relates to a method for producing a rubber product.
However, in the manufacturing method of claim 15, the rubber material is continuously extruded using the twin-screw vent type extruder according to any one of claims 2 to 12, and then vulcanized in a non-pressurized state for a long time. Measure rubber products.
In the method for producing a rubber product according to claim 15, since the air in the rubber material can be sufficiently removed at the stage of continuously extruding the rubber material from the extruder, the unvulcanized extrusion that is continuously extruded thereafter. When the product is vulcanized, it is possible to perform vulcanization without pressure using a vulcanization facility such as an electric oven without using a steam vulcanization facility.
If air is contained in a continuously extruded unvulcanized rubber molded product, when this is vulcanized in a non-pressurized state, the vulcanized product is foamed by the contained air.

However, in the manufacturing method of claim 15, since air can be sufficiently removed from the rubber material extruded from the extruder, such foaming can be prevented even if vulcanization is performed without pressure. It is possible to obtain a good product without foaming.
Thus, since vulcanization can be performed without pressure, that is, without using steam, continuous vulcanization can be easily realized, and expensive equipment installation costs and running for vulcanization with steam are also possible. Costs can be reduced.

It is a figure of the injection molding apparatus which has a biaxial vent type extruder which is one Embodiment of this invention. It is the figure which showed the biaxial vent type extruder of FIG. 1 from the direction different from FIG. It is the figure which expanded and showed the principal part of FIG. It is the perspective view which notched and showed the deaeration chamber and peripheral part in the same embodiment. It is a figure of the connection block in the embodiment. It is the figure which expanded and showed the intersection of the 1st screw and the 2nd screw in the embodiment with a peripheral part. It is explanatory drawing of the manufacturing method of the other Example of this invention. It is explanatory drawing shown in order to demonstrate an example of the conventional single axis vent type extruder with the problem.

Next, an embodiment in which the present invention is applied to an extruder of an injection molding apparatus for a rubber product (in this example, an anti-vibration rubber product) will be described in detail with reference to the drawings.
In FIG. 1, reference numeral 10 denotes an injection molding apparatus, which includes a molding die 12 having a cavity 13 therein, an injection machine 14, and an extruder 16.
The injection machine 14 has an injection chamber 18 inside the injection cylinder 17, and the rubber material charged in the injection chamber 18 with a set charge amount is advanced by the injection plunger 20 downward in the drawing in the drawing cylinder 17. From the nozzle 21 at the front end of the mold 12 into the cavity 13 of the mold 12 at once.
The injection cylinder 17 is provided with a heating medium flow path 22 as a heating means for heating the rubber material in the injection chamber 18.
The injection cylinder 17 is formed with a straight injection passage 24 that reaches the nozzle 21 following the injection chamber 18.

On the other hand, as shown in FIG. 2, the extruder 16 has an upstream first extruder 26 and a downstream second extruder 28 connected thereto.
In the extruder 16, the tape-like unvulcanized rubber material supplied to the inside from the supply port 30 shown in FIG. 2 is plasticized and heated by the rotation of the first screw 32 while being fluidized. It is advanced forward in a downward direction, and is then transferred to the second screw 34 (see FIG. 1) of the second extruder 28.
Then, the rubber material delivered to the second screw 34 is advanced forward to the left in FIG. 1 and passes through the extrusion port 36 at the front end of the second extruder 28 through the extrusion passage 38 and enters the injection chamber 18 of the injection machine 14. Extruded.

  At this time, in the injection machine 14, the injection plunger 20 is moved back upward in the figure by the rubber material pushed into the injection chamber 18, and the rubber material is charged in the injection chamber 18 by the set charge amount. Then, the extrusion by the extruder 16 and the backward movement of the injection plunger 20 are stopped, and then the injection plunger 20 moves forward downward in the figure, and the rubber material in the injection chamber 18 is moved into the mold 12 through the injection passage 24 and the nozzle 21. Eject.

The rubber material injected into the cavity 13 of the mold 12 is heated and held there for a predetermined time and vulcanized.
When the vulcanization process over a predetermined time is completed, the mold 12 is opened, and the internal rubber product is taken out.
A check valve (backflow prevention valve) 40 is provided on the extrusion passage 38 to prevent backflow of the rubber material from the injection chamber 18 into the second extruder 28.

The 1st extruder 26 has the 1st cylinder 42, The 1st screw 32 is rotatably hold | maintained at the inner side.
Moreover, the 2nd extruder 28 has the 2nd cylinder 44, and the 2nd screw 34 is rotatably hold | maintained inside it.
The first cylinder 42 and the second cylinder 44 are provided with a heat medium flow path 22 as heating means.

The first extruder 26 and the second extruder 28 are both oriented in the horizontal direction, and are connected by a connecting block 46 in a state where they intersect at a right angle.
The connection block 46 forms a common housing on the base end side of each of the first screw 32 and the second screw 34.
That is, it constitutes a common component of the first extruder 26 and the second extruder 28.

The second cylinder 44 in the downstream second extruder 28 is fixed to the connecting block 46 with a fixing block 68 and a fastening bolt 70, and the first cylinder in the upstream first extruder 26. The cylinder 42 is fastened and fixed to the connecting block 46 by a fastening bolt 70 at a large-diameter flange portion 72.
The first extruder 26 is disposed above the second extruder 28, and therefore the first screw 32 of the first extruder 26 is disposed above the second screw 34 of the second extruder 28. Yes.

The second screw 34 of the second extruder 28 on the downstream side is cantilevered on the right end side in FIG. 1, and the right end side is operatively connected to the drive motor 48.
The second screw 34 is rotationally driven by the drive motor 48.

As shown in FIG. 1, the second screw 34 includes a screw shaft portion 50 (hereinafter simply referred to as a shaft portion 50) and a flight portion 52 that protrudes from the shaft portion 50 and has a spiral shape around the outer peripheral surface of the shaft portion 50. And a groove (screw groove) 54 formed between the adjacent flight portions 52 and 52.
As shown in FIG. 2, the second extruder 28 is provided with a sensor 56 that detects the number of rotations (rotational speed) of the second screw 34, and this sensor 56 is electrically connected to the controller 58. Has been. Information on the rotational speed from the sensor 56 is sent to the controller 58.

On the other hand, the first screw 32 of the first extruder 26 is rotatably supported at both ends in the axial direction via bearings 60 and 62.
That is, the first screw 32 is supported at both ends in the axial direction.
The first screw 32 is operatively connected to the drive motor 64 on the lower end side in FIG. 2, and the first screw 32 is rotationally driven by the drive motor 64.

The first extruder 26 is also provided with a sensor 66 that detects the rotational speed (rotational speed) of the first screw 32. The sensor 66 is electrically connected to the controller 58, and information on the number of rotations of the first screw 32 by the sensor 66 is sent to the controller 58.
The controller 58 is also electrically connected to a drive motor 48 of the second extruder 28 and a drive motor 64 of the first extruder 26, and the number of revolutions of each is controlled by the controller 58. .

The above is a case where the drive motors 48 and 64 are electric motors. However, when the drive motors 48 and 64 are hydraulic motors, the drive motors 48 and 64 are respectively connected to the drive motors 48 and 64 on a hydraulic circuit that supplies hydraulic oil. A flow rate control valve including an electromagnetic proportional valve for adjusting the supply flow rate of the hydraulic oil is provided, and these flow rate control valves are connected to the controller 58.
In this case, the rotational speed of each of the drive motors 48 and 64 is controlled by controlling the valve opening degree of the flow control valve.

Hereinafter, the case where the drive motors 48 and 64 are electric motors will be described.
The outer diameter D ₁ of the first screw 32 is larger than the outer diameter D ₂ of the second screw 34.
The first screw 32 is configured to be shorter than the second screw 34.
As shown in FIG. 2, the upstream first screw 32 also projects from a screw shaft portion 74 (hereinafter simply referred to as a shaft portion 74) and the outer peripheral surface of the shaft portion 74, and around the outer peripheral surface of the shaft portion 74. The flight portion 76 has a spiral shape, and a groove (screw groove) 78 formed between the adjacent flight portions 76 and 76.

As shown in FIG. 6, the first screw 32 and the second screw 34 intersect at right angles so as to overlap with the first screw 32 positioned on the upper side and the second screw 34 positioned on the lower side. Yes.
In the first screw 32, a weir 80 having the same outer diameter as that of the flight part 76 is provided over the entire circumference at an upstream portion adjacent to the intersection with the second screw 34.

A large number of small grooves 84 that penetrate the weir 80 in the width direction from the left end to the right end in FIG. 6 are provided on the outer peripheral portion of the weir 80 at a constant pitch in the circumferential direction. A narrow passage 86 for allowing the rubber material to pass therethrough is formed.
In this embodiment, the rubber material flows through these small grooves 84 to the right in FIG. 6 and flows into a delivery portion 88 adjacent to the downstream side of the weir 80, that is, formed at the intersection, as a thread. .

Here, each of the small grooves 84 is opposite to the rotational direction of the first screw 32 indicated by the arrow P ₁ in FIG. 6A as it advances toward the delivery portion 88 with respect to the direction parallel to the axial direction of the first screw 32. It is set as the inclination shape and straight shape which shift to the direction, ie, the rotation direction of the rubber material which rotates in the opposite direction relatively with respect to the 1st screw 32.
That is, each of the small grooves 84 has a shape inclined with respect to the axial direction of the first screw 32 on the same side as the flight part 76 when viewed in the direction perpendicular to the central axis in FIG.

The first screw 32 has a circular medium diameter portion 94 following the weir 80 and the large diameter portion 92 on the proximal end side shown in FIG. 2 (the medium diameter portion 94 has the same outer diameter as the flight portion 76 and the weir 80). In between, the delivery part 88 is provided on the outer peripheral surface of the screw shaft part 74.
Here, the delivery part 88 forms a deaeration chamber 98 on the outer peripheral side together with a recess 96 formed in the connection block 46 shown in FIG.
The delivery portion 88 forms a groove space 89 in an annular shape along the circumferential direction. The groove space 89 forms a part of the deaeration chamber 98 described above.
In FIG. 3, reference numeral 100 denotes a vent hole opened to the deaeration chamber 98, and the inside of the deaeration chamber 98 is evacuated by the vacuum pump 102 through the vent hole 100.

As shown in FIG. 3, the connecting block 46 has an insertion space 104 having a circular cross section through which the second screw 34 is inserted, and this insertion space 104 is connected to the internal space of the second cylinder 44. .
As shown in FIGS. 4 and 5, a part of the insertion space 104 is also connected to the recess 96 in the connecting block 46 shown in FIG. 3. Therefore, the insertion space 104 is also a recess. The outer peripheral portion of the portion connected to 96, that is, the portion excluding the second screw 34 forms a part of the deaeration chamber 98.
The insertion space 104 is closed by a base 106 having a circular cross section of the second screw 34 and the same outer diameter as the flight part 52.

As shown in FIG. 6B, the delivery portion 88 has a shape that decreases in diameter from both ends in the axial direction toward the intermediate portion.
Specifically, the delivery portion 88 has an arc shape in which the end portion 88a on the weir 80 side is reduced in diameter as it advances from the end position of the same outer diameter as the maximum outer diameter of the weir 80 to the right in FIG. Further, the intermediate portion 88c following the end portion 88a has a straight axial shape, and the end portion 88b on the medium diameter portion 94 side following the intermediate portion 88c faces the intermediate diameter portion 94 from the intermediate portion 88c. As the diameter gradually increases, the arc shape is formed so as to be connected to the outer peripheral surface at the right end in the drawing so as to coincide with the outer diameter of the intermediate diameter portion 94.

As described above, the delivery portion 88 has a shape that becomes smaller in diameter in the axial direction of the first screw 32 from the weir 80 toward the center in the radial direction of the second screw 34, and particularly from both ends in the axial direction toward the intermediate portion. The second screw 34 has a constricted shape corresponding to the shape of the flight portion 52 of the second screw 34 in which the outer peripheral portion on the first screw 32 side has an arc-shaped convex curved shape. There is no.
The outer peripheral portion of the flight portion 52 enters the groove space 89 formed on the outer peripheral side of the constricted delivery portion 88 as viewed in the axial direction of the second screw 34.
That is, the second screw 34 on the downstream side passes through a position where the flight portion 52 of the second screw 34 enters the radially inward direction of the first screw 32 from the outer peripheral end of the weir 80 toward the delivery portion 88. In addition, the first screw 32 is disposed in the vicinity.

  In this embodiment, the second screw 34 is located on the right side in the drawing with respect to the delivery portion 88 in FIG. 6B, and the clearance between the flight portion 52 and the delivery portion 88 is the end portion 88b. And the flight portion 52, the minimum clearance C is 1 mm here.

In this embodiment, the inside of the deaeration chamber 98 is a vent zone.
In this embodiment, the tape-like unvulcanized rubber material continuously supplied from the supply port 30 of FIG. 2 into the first extruder 26 is plasticized under heating as the first screw 32 rotates. While being fluidized, it is forwardly fed downward in FIG. 2, and reaches the upstream position immediately before the weir 80 in FIG.
The rubber material reached here moves from the outer peripheral surface of the shaft portion 74 of the first screw 32 to the outer peripheral portion of the weir 80 under the guidance of the tapered guide portion 90.
The rubber material that has reached the outer peripheral portion of the weir 80 flows into the small grooves 84 provided at regular intervals along the outer peripheral portion of the weir 80 and then flows to the right in the figure.

In this case the rubber material, the rotation shown in FIG. 6 (A) Medium P ₁ direction of the first screw 32 is rotated relative movement with respect to the first screw 32 in the opposite direction, thus the rubber material is smoothly small groove It is possible to flow in the small groove 84 having a shape inclined in the same direction as the rotation direction while entering the 84 and maintaining the relative rotation direction.
Therefore, the rubber material can pass through the small groove 84 smoothly.

The rubber material that has flowed and passed through the small groove 84 is threaded and flows into the delivery portion 88 adjacent to the weir 80. That is, it flows into the deaeration chamber 98.
At this time, the rubber material has an increased surface area, and the air contained in the rubber material is satisfactorily removed by being evacuated in the deaeration chamber 98 in this state.

The rubber material that has flowed into the delivery unit 88 is then delivered from the delivery unit 88 to the second screw 34. At this time, the rubber material in the delivery unit 88 must be successfully bitten by the second screw 34. The rubber material accumulates and stays at the delivery part 88.
If it does so, there exists a possibility that the rubber material which accumulated and stayed in the delivery part 88 may raise | generate a scorch at high temperature.

  When the scorch-induced rubber (burnt rubber) is mixed with a regular rubber material that does not generate scorch and is bitten into the second screw 34, the burnt rubber is finally converted into a rubber product. It may get inside and cause deterioration of the properties of rubber products or cause product defects.

However, in this embodiment, the second screw 34 on the downstream side passes through the delivery portion 88 in a direction orthogonal to the first screw 32 with the delivery portion 88 entering the groove space 89 formed on the outer peripheral side. Therefore, the rubber material that has flowed into the delivery portion 88 is quickly scraped off by the flight portion 52 of the second screw 34 and then flows out of the delivery portion 88, and is further bitten by the second screw 34 and is shown in FIG. Moves forward in the middle left direction.
And finally, it is extruded into the injection machine 14 from the extrusion port 36 at the front end of the second extruder 28, and then injected into the cavity 13 of the mold 12 by the downward advance of the injection plunger 20 in FIG. It is heated and vulcanized in the mold 12 for a predetermined time to obtain a rubber product.

In the present embodiment as described above, the deaeration chamber is adjusted by adjusting the rotation speed (rotational speed) between the first screw 32 of the first shaft on the upstream side and the second screw 34 of the second shaft on the downstream side. The balance between the inflow amount of the rubber material to 98 and the outflow amount of the rubber material from the deaeration chamber 98 can be made an optimal balance.

Thereby, the amount of the rubber material in the deaeration chamber 98 can be held at an appropriate constant amount while sufficiently securing the amount of extrusion from the extrusion port 36 at the front end of the second cylinder 44, and the properties of the rubber material are different. Thus, the problem that the deaeration amount in the deaeration chamber 98 varies can be solved, the deaeration amount in the deaeration chamber 98 can be made constant, and the deaeration efficiency can be effectively increased.
Further, since the inflow amount (inflow rate) of the rubber material into the deaeration chamber 98 is larger (faster) than the outflow amount (outflow rate) of the rubber material from the deaeration chamber 98, the rubber material enters the deaeration chamber 98. Therefore, it is possible to satisfactorily prevent the occurrence of a vent-up in which the vent hole 100 is blocked.

Even if the inflow amount of the rubber material into the deaeration chamber 98 and the outflow amount of the rubber material from the deaeration chamber 98 are set to be balanced, the rubber material in the deaeration chamber 98 is on the downstream side. If the second screw 34 does not penetrate well, the rubber material may accumulate in the deaeration chamber 98 and accumulate, which may eventually cause a problem of vent-up. In this embodiment, the first screw 32 has a delivery part 88 having a smaller diameter than the outermost diameter of the weir 80 and no flight part, and the second screw 34 is provided so as to intersect the delivery part 88, and Since the second screw 34 scrapes off the rubber material at the flight part 52 and flows out of the deaeration chamber 98, the rubber material can be prevented from staying and accumulating in the deaeration chamber 98, and the vent hole 100 is made of the rubber material. Bent up blocked by It is possible to prevent the better.
Furthermore, when the flight part 52 of the second screw 34 scrapes off the rubber material from the delivery part 88, the efficiency of deaeration in the deaeration chamber 98 can be further increased because the rubber material is pulled and stretched.

  Further, since the rubber material is successfully delivered from the delivery portion 88 at the intersection of the first screw 32 to the second screw 34, it is possible to prevent the rubber material from staying and accumulating in the deaeration chamber 98. Since the degassing chamber 98 is widely occupied by accumulated rubber material, the problem of insufficient degassing amount in the degassing chamber 98 can be solved, and the degassing quality and degassing efficiency can be kept constant and high. It can be kept efficient.

  Furthermore, in the present embodiment, scorch due to the retention of the rubber material in the deaeration chamber 98 is prevented, and the burnt rubber is mixed into the regular rubber material, and enters the rubber product as it is, thereby deteriorating the characteristics of the rubber product and the product. Problems that cause defects can be solved satisfactorily.

In the present embodiment, since the shape of the delivery portion 88 is a shape having a small diameter from the weir 80 toward the radial center of the second screw 34 in the axial direction of the first screw 32, the flight portion of the second screw 34. The rubber material 52 can be scraped off more favorably in the delivery part 88.
In particular, since the shape of the delivery portion 88 is a constricted shape corresponding to the outer peripheral shape of the flight portion 52 of the second screw 34, the rubber material of the delivery portion 88 can be scraped off reliably.
Thereby, it is possible to more reliably prevent the rubber material from accumulating and staying in the deaeration chamber 98.

  In the present embodiment, the inclination of the shape that shifts in the relative rotation direction of the rubber material with respect to the first screw 32 as each of the small grooves 84 in the outer peripheral portion of the weir 80 constituting the narrow passage 86 advances toward the delivery portion 88 side. Because of the shape, the rubber material that has just reached the upstream side of the weir 80 can be smoothly guided into the small groove 84 and can flow along the small groove 84, and the rubber material can smoothly move the weir 80 through the small groove 84. By not being able to overflow, it is possible to prevent a large amount of stagnation just before the weir 80.

  Further, a tapered guide portion 90 having a diameter increasing toward the weir 80 is provided in an upstream portion adjacent to the weir 80, and the rubber material flows toward the small groove 84 on the outer peripheral side of the weir 80 by the guide portion 90. Since it can guide, it can prevent still more effectively that a rubber material retains much in the position immediately upstream of the weir 80. FIG.

  In the present embodiment, since the first screw 32 and the second screw 34 are respectively oriented in the horizontal direction and arranged so as to cross each other, the supply port 30 is arranged at an appropriate position on the nearby passage side. Therefore, the workability during the extrusion operation can be improved.

  In the present embodiment, the second screw 34 is formed by the weir 80 because the portion on the first screw 32 side in the outer peripheral portion is rotated in the feeding direction of the rubber material by the first screw 32. The rubber material that has passed through the narrow passage 86 and has been fed into the transfer portion 88 at the intersection can be pulled in the feeding direction by the rotation of the second screw 34, thereby increasing the surface area of the rubber material. The deaeration efficiency can be increased.

Further, in the present embodiment, since the first screw 32 is supported at both ends in the axial direction, the first screw 32 can be firmly supported with high rigidity. Therefore, it is possible to satisfactorily prevent the clearance C between the second screw 34 from fluctuating.
Moreover, it can maintain in the proper positional relationship which set the positional relationship of the flight part 52 of the 2nd screw 34, and the delivery part 88 of the 1st screw 32, and with respect to the rubber material which flowed into the delivery part 88 Good scraping by the flight part 52 of the second screw 34 can be ensured.

  In the present embodiment, since the first screw 32 is shorter than the second screw 34 and the rigidity of the first screw 32 is high, the core runout of the first screw 32 can be more effectively prevented. it can.

  Further, the first screw 32 has a larger diameter than the second screw 34, so that the rigidity thereof is further increased.

In addition, by making the first screw 32 larger in diameter than the second screw 34 in this way, the radial passage width in the narrow passage 86 is reduced, and the surface area when the rubber material passes through the passage is increased. Since the circumferential length in the rotation direction can be increased while effectively increasing the width of the narrow passage 86, a wide passage area of the narrow passage 86 can be secured.
As a result, the rubber material can be effectively reduced in thickness while being allowed to flow into the delivery portion 88 at the intersection, that is, the deaeration chamber 98, and the rotation speed of the first screw 32 is not particularly increased (if the rotation speed is increased). The heat generated by the rubber material becomes large) and the amount of inflow can be increased.
Therefore, the problem that the amount of extrusion from the extrusion port 36 at the front end of the second cylinder 44 cannot be increased due to the inflow amount of the rubber material into the deaeration chamber 98 cannot be increased. By increasing the surface area of the rubber material flowing into the tank, it becomes easy to ensure a sufficient amount of extrusion while increasing the deaeration efficiency.

  In addition, when the diameter of the screw of the existing extruder incorporated in the heating molding apparatus such as the extruder in the injection molding apparatus 10 is made larger than that of the current state, a large cost is required, but the first screw 32 described above is required. Can be added to the existing screw. In this case, the extruder 16 of the present embodiment can be configured while using the screw of the existing extruder as it is. The extruder 16 of this embodiment can be constructed at a cost.

When the anti-vibration rubber product is manufactured according to the manufacturing method of the present example as described above, the phenomenon that the anti-vibration rubber product is foamed by the air in the rubber material during the vulcanization treatment can be prevented, and the quality without bubbles. A good anti-vibration rubber product can be produced.
The anti-vibration rubber products shown in this example include all anti-vibration rubber products such as an anti-vibration rubber product whose main body is made only of rubber and an anti-vibration rubber product having a fluid chamber in which an incompressible fluid is enclosed. Is included.
Further, in the present example, the present invention has been described by taking an anti-vibration rubber product as an example, but the present invention can also be suitably applied to a rubber product such as a roll product as an OA equipment related product.

  In this embodiment, the biaxial vent type extruder 16 is assembled to the injection molding apparatus 10, but the rubber material is extruded by using the extruder 16 of this example alone, and the second extruder is used. It is also possible to produce a rubber product by vulcanizing the degassed rubber extruded from the extrusion port. Even if it does in this way, the phenomenon that a rubber product foams with the air in a rubber material in the case of a vulcanization | cure process can be prevented, and a rubber product with favorable quality can be manufactured.

The above biaxial vent type extruder can also be used as an extruder for producing a long rubber product in addition to an extruder for injection molding.
FIG. 7 shows an example used as an extruder when producing a rubber hose as an example.
In this example, the rubber material is continuously extruded to cover the mandrel 122 in the head 120 while continuously passing the resin mandrel 122 through the head 120 provided at the tip of the extruder 16.
Then, the unvulcanized rubber hose 124A extruded in a cylindrical shape so as to cover the mandrel 122 from the head 120 is continuously connected to a non-pressurized vulcanization facility 126 including an electric oven disposed downstream in the traveling direction. Then, the unvulcanized rubber hose 124A is continuously vulcanized in the vulcanization facility 126 to produce a long vulcanized rubber hose 124.
The vulcanized rubber hose 124 and the mandrel 122 are separated thereafter, and the vulcanized long rubber hose 124 is then cut to an appropriate length.

According to this method of manufacturing the rubber hose 124, the air in the rubber material can be sufficiently removed at the stage where the rubber material is continuously extruded from the extruder 16, so that the unvulcanized rubber hose 124A continuously extruded thereafter is used. When the vulcanization process is performed, it is possible to perform the vulcanization process without pressure using the vulcanization facility 126 including an electric oven without using the steam vulcanization facility.
If air is contained in the continuously extruded unvulcanized rubber hose 124A, when vulcanized in an unpressurized state, the vulcanized product is foamed by the contained air. Then, since the air can be sufficiently removed from the rubber material extruded from the extruder 16, such foaming can be prevented even when vulcanization is performed without pressure, and good foaming is prevented. A product can be obtained.
Thus, since vulcanization can be performed without pressure, that is, without using steam, continuous vulcanization can be easily realized, and expensive equipment installation costs and running for vulcanization with steam are also possible. Costs can be reduced.

Although the embodiment of the present invention has been described in detail above, this is merely an example.
For example, the first screw on the upstream side and the second screw on the downstream side may intersect at an angle other than a right angle, and the present invention can be applied to an extruder for various uses. It is possible to make the shape of the delivery part 88 into other various shapes.
In the above embodiment, a large number of small grooves 84 are provided along the outer periphery of the weir 80, and the narrow passage 86 is formed by the entire small groove 84. However, the weir 218 as shown in FIG. The present invention can be configured in various modifications without departing from the spirit of the present invention, such as a narrow passage having a gap between the weir and the cylinder inner surface.

DESCRIPTION OF SYMBOLS 10 Injection molding apparatus 12 Mold 13 Cavity 14 Injection machine 16 Extruder 32 1st screw 34 2nd screw 52,76 Flight part 80 Weir 84 Small groove 86 Narrow passage 88 Delivery part 90 Guide part 98 Deaeration chamber 100 Vent hole

Claims (15)

The biaxial screw is provided so as to intersect with each other so that the first screw on the upstream side has a weir at the upstream portion adjacent to the intersecting portion and forms a narrow passage of the extruded material by the weir. The crossing portion has a delivery portion for the extruded material having a diameter smaller than the outermost diameter of the weir on the outer circumferential surface of the screw shaft portion, and is removed by vacuum suction through a vent hole on the outer circumference side of the delivery portion. It is supposed to form an air chamber,
In the second screw on the downstream side, the flight portion of the second screw enters the radially inner side of the first screw from the outer peripheral end of the weir toward the delivery portion in the axial direction of the second screw. In a position to be in a state, it is arranged close to the first screw,
The extruding material flowing into the delivery section through the narrow passage of the first screw is fed forward by the second screw that intersects the delivery section by scraping at the flight section. A featured twin screw vent extruder.   The twin screw vent type extruder according to claim 1, wherein the extrusion material is a rubber material.   In any one of Claims 1, 2, The said delivery part is a shape which becomes a small diameter toward the center of the radial direction of the said 2nd screw from the said dam in the axial direction of the said 1st screw, It is characterized by the above-mentioned. Two-screw vent type extruder. In Claim 3, the delivery portion has a constricted shape that decreases in diameter from both axial ends toward the intermediate portion, and the flight portion of the second screw is in the axial direction view of the second screw. A biaxial vent type extruder characterized by being positioned in a groove space formed on the outer peripheral side of a constricted shape.   The twin-screw vent type extruder according to any one of claims 1 to 4, wherein the delivery portion of the first screw does not have a flight portion.   6. The narrow passage according to claim 1, wherein the narrow passage is composed of a plurality of small grooves formed in an outer peripheral portion of the weir, and the small grooves are in the intersecting portion with respect to the axial direction of the first screw. A twin-screw vent type extruder having an inclined shape that moves in the direction of relative rotation of the extruded material with respect to the first screw as it advances toward the delivery portion.   7. The twin-screw vent type extruder according to claim 6, wherein a guide portion whose diameter increases toward the weir is provided in an upstream portion adjacent to the weir on an outer peripheral portion of the first screw.   The twin screw vent type extruder according to any one of claims 1 to 7, wherein the first screw and the second screw are respectively oriented in a horizontal direction.   In any 1 item | term of the said 1st screw, the said 2nd screw WHEREIN: The site | part by the side of the said 1st screw in an outer peripheral part becomes what shall rotate in the feed direction of the said extrusion material by this 1st screw. A biaxial vent type extruder.   The biaxial vent type extruder according to any one of claims 1 to 9, wherein the first screw is rotatably supported at both ends in the axial direction.   The twin screw vent type extruder according to any one of claims 1 to 10, wherein the first screw is shorter than the second screw.   The twin screw vent type extruder according to any one of claims 1 to 11, wherein the first screw has a larger diameter than the second screw.   A rubber product obtained by injecting a rubber material into a cavity of a mold using the biaxial vent type extruder according to any one of claims 2 to 12, and vulcanizing with the mold. Manufacturing method.   A rubber product obtained by extruding a rubber material using the biaxial vent type extruder according to any one of claims 2 to 12 and vulcanizing the deaerated rubber after extrusion. Product manufacturing method.   A rubber material is continuously extruded using the twin-screw vent type extruder according to any one of claims 2 to 12, and a degassed rubber extrudate after extrusion is vulcanized in a non-pressurized state for a long time. A method for producing a rubber product, characterized in that a rubber product is obtained.

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