JP2017065210A - Rubber extrusion device and method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber extrusion device and a rubber extrusion method, which, while having a simple structure, suppress a rubber extrusion product from shrinking in the extrusion direction, shorten a necessary time until becoming a state that does not cause shrinkage, and can suppress air from remaining in the inside of the rubber extrusion product.SOLUTION: By extending a straightening body 8 from a proximity of a front end surface of an extrusion port 6 toward a cylinder 2 side at least up to the inside of an extrusion channel of a die 5, with a space on a front surface side of the straightening body 8 and external air communicated through a penetration path 10 having an opening on a front surface of the straightening body 8 via the inside of the straightening body 8, a rubber extrusion product R is extruded from the extrusion port 6 by passing unvulcanized rubber R1 extruded forward by a screw 4 through a gap between an inner surface of the extrusion channel and the straightening body 8, and, through the penetration path 10, a thread member S is discharged from a front surface of the straightening body 8 to a front direction followed by embedding in the rubber extrusion product R, and thereby, air A of the rubber inside is externally discharged through the penetration path 10.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a rubber extrusion apparatus and method, and more particularly, while having a simple configuration, the shrinkage of the rubber extrudate in the extrusion direction is suppressed, and the time required to reach a non-shrinkable state is reduced. The present invention relates to a rubber extrusion apparatus and method capable of suppressing air remaining inside a product.

  When manufacturing rubber products such as tires, there is an extrusion process in which unvulcanized rubber is extruded by a rubber extrusion device. In the rubber extrusion device, the unvulcanized rubber is plasticized by an internal screw, and is extruded from an extrusion port formed in the die at the tip to form a rubber extrudate molded into a predetermined shape. This rubber extrudate is cut to a predetermined length after cooling. Since rubber has viscoelastic properties, the strain in the extrusion process is stored in the interior as energy, and after cutting due to this, it shrinks (shrinks) mainly in the extrusion direction. If the shrinkage is excessive, a difference from a preset dimension becomes large, and there is a problem that troubles occur in a subsequent process.

  Various methods for solving such problems have been proposed in the past (see, for example, Patent Document 1). In Patent Document 1, the rubber extrudate is vibrated by a vibration device arranged on the downstream side of the extruder to increase the shrinkage speed of the rubber. In this way, the rubber extrudate is sufficiently shrunk to prevent shrinkage in the subsequent process.

  As another countermeasure, a method is known in which a plurality of transport conveyors are arranged in series on the downstream side of the extruder, and the downstream transport conveyor and the transport speed are set slower. In this method, the rubber extrudate is forcibly contracted when the transfer conveyor is transferred to prevent contraction in the subsequent process. However, these conventional measures have a problem that the apparatus becomes large.

JP-A-8-244090

  The object of the present invention is to suppress the shrinkage of the rubber extrudate in the extruding direction while reducing the time required for the rubber extrudate to become non-shrinkable, and to suppress the air remaining inside the rubber extrudate. It is an object of the present invention to provide a rubber extrusion apparatus and method.

  In order to achieve the above object, a rubber extrusion device according to the present invention comprises a cylindrical cylinder, a screw disposed in the cylinder, a head installed at the tip of the cylinder, and a pusher disposed at the tip of the head. In a rubber extrusion device comprising a die having an outlet, a rectifying body extending from the vicinity of the front end face of the extrusion port toward at least the inside of the extrusion flow path of the die toward the cylinder side, and the inside of the rectifying body A through passage having an opening on the front surface of the rectifier and a thread member passing through the through passage, and the space on the front side of the rectifier and the outside air are in communication with each other through the through passage. Then, the rubber extruded by the screw is passed through the gap between the inner surface of the extrusion flow path and the rectifying body to push out the rubber extrudate from the extrusion port, and through the through path. The thread member continues discharged forward from the front surface of the rectifying body, characterized in that it has a configuration that the state of being embedded in the rubber extrudate.

  In the rubber extrusion method of the present invention, a rubber material is charged into a cylindrical cylinder, and the unvulcanized rubber mixed and kneaded while pushing the rubber material forward by a screw provided in the cylinder, In a rubber extrusion method for extruding as a rubber extrudate from an extrusion port of a die disposed at a tip end of a head installed at a tip of a cylinder, at least the extrusion of the die from the vicinity of the front end surface of the extrusion port toward the cylinder side A rectifier is extended to the inside of the flow path, and a through passage having an opening is formed in the front of the rectifier through the inside of the rectifier, and the space on the front side of the rectifier through the through passage The unvulcanized rubber extruded forward by the screw is allowed to pass through the gap between the inner surface of the extrusion flow path and the rectifying body, and is passed through the extrusion port. With extruding a serial rubber extrudate, characterized in that for embedding the thread member through the through-passage in the rubber extrudate continues is discharged forward from the front surface of the rectifying body.

  According to the present invention, by passing the rubber extruded by the screw between the inner surface of the extrusion channel and the rectifier, the rubber comes into contact with the inner surface of the extrusion channel and the surface of the rectifier. While being pushed out from the extrusion port. The strain in the direction orthogonal to the extrusion direction remains in the portion in contact with the inner surface of the rubber extrusion channel and the surface of the rectifier. When these portions are extruded from the extrusion port, they exhibit a behavior of extending in the extrusion direction due to this strain, and as a result, shrinkage of the rubber extrudate can be suppressed. Moreover, since the rectifying body protrudes from the front end face of the extrusion port, the rubber of the rubber extrudate can be left with the maximum distortion in the direction perpendicular to the extrusion direction. The effect of suppressing the shrinkage of is increased. That is, the shrinkage of the rubber extrudate in the extruding direction can be suppressed immediately after extrusion, while having a simple configuration provided with a rectifier without requiring a large structure. This makes it possible to shorten the time required for the rubber extrudate to be in a state where it does not shrink.

  On the other hand, the rubber that has passed through the rectifier is temporarily divided by the rectifier, and air tends to remain at the joining boundary where the divided rubbers are joined. Therefore, in the present invention, air inside the rubber can be discharged to the outside through the through passage by allowing the space on the front side of the rectifier to communicate with the outside air through the through passage. Moreover, since the thread member is passed through the through passage and continuously discharged from the front surface of the rectifying body, the through passage is not blocked by rubber and air can be stably discharged to the outside.

  Further, even if air remains in the rubber extrudate, the air can be discharged to the outside of the rubber extrudate through the thread member embedded in the rubber extrudate. Therefore, the remaining air can be suppressed even when compared with a rubber extrudate extruded by a conventional rubber extruding apparatus in which a rectifier is not installed in the extrusion flow path.

  Here, for example, the extension length from the front end surface of the extrusion port of the rectifier to the cylinder side is set to 10 mm or more. According to this specification, distortion in a direction orthogonal to the extrusion direction can be sufficiently applied to the rubber portion that contacts the surface of the rectifying body. Therefore, it is advantageous for suppressing shrinkage in the extrusion direction of the rubber extrudate.

  For example, the rectifier is plate-shaped. By making it a plate-like rectifier, it is possible to prevent excessive resistance to rubber passing therethrough, so that rubber can be easily extruded smoothly.

  The position of the tip of the rectifier is, for example, in the range of 10 mm forward to 10 mm backward from the front end face of the extrusion port. If the position of the tip of the rectifying body is more than 10 mm forward from the front end face of the extrusion port, air tends to remain in the rubber extrudate. On the other hand, if this position is more than 10 mm rearward from the front end face of the extrusion port, the effect of suppressing shrinkage in the extrusion direction of the rubber extrudate becomes small.

  As the thread member, for example, a breaking strength is 100 N or less and a twisted structure is adopted. When the breaking strength of the thread member is more than 100 N, it is difficult to ignore the influence of the thread member in the rubber product obtained by vulcanizing the rubber extrudate. In addition, when a yarn member having a twisted structure is used, air inside the rubber extrudate can be easily discharged to the outside through the yarn member.

It is explanatory drawing which illustrates the rubber extrusion apparatus of this invention by planar view. It is explanatory drawing which illustrates die | dye of FIG. 1 by front view. It is explanatory drawing which illustrates the head periphery of FIG. 1 by side surface sectional view. It is explanatory drawing which illustrates the effect by which the shrinkage | contraction of the extrusion direction of a rubber extrudate is suppressed by the baffle provided in the rubber extrusion apparatus of this invention in a side sectional view. It is explanatory drawing which illustrates the state which is extruding a rubber extrudate and has embed | buried the thread | yarn member in a rubber extrudate in side surface sectional view. It is explanatory drawing which illustrates the head periphery of another embodiment of the rubber extrusion apparatus of this invention by side sectional view. It is explanatory drawing which illustrates the die | dye of further another embodiment of the rubber extrusion apparatus of this invention by a front view. FIG. 8 is an explanatory diagram illustrating the periphery of the head of FIG. 7 in a side sectional view. It is explanatory drawing which illustrates the state of the rubber extrudate immediately after extruded with the conventional rubber extrusion apparatus by side sectional view.

  Hereinafter, the rubber extrusion apparatus and method of the present invention will be described based on the embodiments shown in the drawings.

  A rubber extrusion device 1 of the present invention illustrated in FIGS. 1 to 3 includes a cylindrical cylinder 2, a screw 4 disposed inside the cylinder 2, and a head 3 installed at the tip of the cylinder 2. Yes. A die 5 is attached to the tip of the head 3. An extrusion port 6 is formed in the die 5. The rubber extrusion device 1 further includes a rectifier 8 and a yarn member S supplied from a yarn supply reel 11. In FIG. 1, the rubber extrudate R is indicated by a virtual line (two-dot chain line). The rectifying body 8 has a flat plate shape, but besides the plate shape, various shapes such as a cone shape and a pyramid shape can be adopted as the column shape.

  The front end 8a of the rectifying body 8 is located in the vicinity of the front end surface of the extrusion port 6, and the rear end 8b of the rectifying body 8 is at least a position inside the extrusion flow path 7 of the die 5 toward the cylinder 2 side. That is, the rectifier 8 extends from the vicinity of the front end face of the extrusion port 6 toward the cylinder 2 side to at least the inside of the extrusion flow path 7 of the die 5.

  In the present invention, the vicinity of the extrusion port 6 is, for example, a range from 10 mm forward to 10 mm from the front end surface of the extrusion port 6. In this embodiment, the front end 8a of the rectifying body 8 is in a position protruding forward from the front end face of the extrusion port 6 by a protruding length a, and the protruding length a is preferably 10 mm or less.

  The extending length b from the front end face of the extrusion port 6 of the rectifier 8 toward the cylinder 2 is preferably 10 mm or more. The rectifying body 8 is fixed to the die 5 via a connecting portion 9 extending downward from the rectifying body 8, and extends across the extrusion flow path 7 formed in the die 5 and the head 3. The rectifying body 8 can be extended only to the extrusion flow path 7 formed in the die 5, but may be installed inside the extrusion flow path 7 formed in the die 5 and the head 3. The upper limit of the extension length b is, for example, about 100 mm, but is not limited to this, and can be about 200 mm.

  In this embodiment, a single flat plate-like rectifying body 8 is arranged with the plate thickness direction facing the thickness direction of the extrusion port 6, and is arranged at the center in the width direction of the extrusion port 6. The gaps w and w in the width direction between the extrusion channel 7 and the rectifier 8 are 10 mm or more. The left and right clearances w and w can be different, but they should be the same. The gaps t1 and t2 in the thickness direction between the extrusion channel 7 and the rectifier 8 are each 0.5 mm or more. The upper and lower gaps t1 and t2 can be different, but are preferably the same.

  The rectifying body 8 is formed with a through passage 10 having an opening on the front surface thereof through the inside thereof. In this embodiment, one end opening of the through passage 10 is located on the front surface of the rectifier 8, and the other end opening is located on the lower surface of the die 5. The through passage 10 passes through the rectifying body 8, the connection portion 9, and the die 5, and the space on the front side of the rectifying body 8 and the outside air are in communication with each other through the through passage 10.

  The position of the other end opening of the through-passage 10 is not limited to this, as long as the space on the front side of the rectifier 8 and the outside air can be communicated with each other through the through-passage 10. For example, the other end opening of the through passage 10 can be provided on the front surface, the side surface, or the head 3 of the die 5.

  The thread member S is wound around the thread supply reel 11. The yarn member S fed out from the yarn supply reel 11 is supported by the support roller 11 a in the middle and inserted into the other end opening of the through-passage 10. The thread member S inserted into the other end opening of the through passage 10 passes through the through passage 10 and is discharged from one end opening on the front surface of the rectifying body 8.

  The support roller 11 a has a function of applying an appropriate tension to the thread member S and a positioning function of smoothly inserting the thread member a into the other end opening of the through-passage 10. For example, the yarn supply reel 11 and the support roller 11a are configured to smoothly rotate freely.

  The inner diameter of the through-passage 10 is set to a size that allows the thread member S to pass smoothly, but is not excessive with respect to the outer diameter of the thread member S. For example, the inner diameter of the through passage 10 is set to be about 0.5 mm to 3 mm larger than the outer diameter of the thread member S.

  For example, the thread member S has a breaking strength of 100 N or less. Various materials can be used for the thread member S. For example, synthetic fibers such as nylon, polyester, and rayon, and natural fibers such as cotton are used. The thread member S preferably has a twisted structure.

  Next, the procedure of the rubber extrusion method of the present invention for producing the rubber extrudate R with the thread member S embedded therein will be described. When the rubber extrudate R is extruded by the rubber extrusion device 1 in the production line, a predetermined amount of rubber material (unvulcanized rubber and compounding agent) is put into the cylinder 2. The rubber material is mixed and kneaded by the rotating screw 4. The unvulcanized rubber R1 produced by mixing and kneading is softened to some extent (plasticized) and molded into a cross-sectional shape from the extrusion port 6 to the extrusion port 6 to obtain an unvulcanized rubber extrudate R. Extruded into a sheet. For example, a rubber extrudate R such as a tire tread rubber formed in a predetermined shape is manufactured from the present invention.

  At this time, the rubber R1 pushed forward by the screw 4 passes through the gap between the extrusion flow path 7 and the rectifying body 8 and is pushed out from the extrusion port 6. That is, the rubber R1 extruded from the cylinder 2 side by the screw 4 is extruded as a plate-like rubber extrudate R from the extrusion port 6 while being in contact with the inner surface of the extrusion flow path 7 and the surface of the rectifier 8. Next, the rubber extrudate R is conveyed to a subsequent process.

  Here, in the conventional rubber extrusion device illustrated in FIG. 9 that does not include the rectifying body 8, the rubber extrudate R is extruded from the extrusion port 6 while being in contact with the inner surface of the extrusion flow path 7. At this time, strain in a direction orthogonal to the extrusion direction remains in a portion that contacts the inner surface of the extrusion flow path 7. The inventor of the present invention observes and analyzes the shapes of a large number of rubber extrudates R by a conventional rubber extruding device, and as shown in FIG. As a result, it has been found that it exhibits a behavior of extending in the tip direction (extrusion direction) due to this strain.

  Therefore, the tip of the rubber extrudate R has a shape in which the outer peripheral portion relatively protrudes in the tip direction (extrusion direction) and the central portion of the cross section is relatively recessed backward. That is, if a strain is left in the direction orthogonal to the extrusion direction immediately before the rubber extrudate R is extruded, the portion extends in the extrusion direction after extrusion, and accordingly, shrinkage of the central portion of the cross section to be contracted is suppressed. To do. The present invention utilizes this principle.

  In the rubber extrusion apparatus 1 of the present invention, as illustrated in FIG. 4, strain in a direction orthogonal to the extrusion direction remains in a portion that contacts the inner surface of the extrusion flow path 7 and the surface of the rectifying body 8. When the portion where the strain remains is extruded, the portion that extends in the extrusion direction due to the strain exhibits a behavior, so that the portion that extends in the extrusion direction increases compared to the conventional case. As a result, the contraction of the central portion of the cross section to be contracted is suppressed, and the contraction of the rubber extrudate R is suppressed as a whole.

  Moreover, in the present invention, since the rectifying member 8 protrudes forward from the front end face of the extrusion port 6, the rubber of the rubber extrudate R can be left with the maximum strain in the direction perpendicular to the extrusion direction. . Along with this, the effect of suppressing the shrinkage of the rubber extrudate R can be maximized.

  Therefore, according to the rubber extrusion device 1 of the present invention, the rubber extrudate R is contracted in the extrusion direction immediately after extrusion, while having a simple structure provided with the rectifying body 8 without requiring a large structure. It becomes possible to suppress. As a result, it is possible to shorten the time required until the rubber extrudate R does not contract.

  If the protruding length a forward from the front end face of the extrusion port 6 of the rectifying body 8 is about 10 mm, the rubber R1 temporarily divided by the rectifying body 8 is divided in the extruded flow. Soon after, the divided surfaces will naturally join together. That is, the divided surfaces of the rubber extrudate R are automatically joined together by the swell of unvulcanized rubber divided by the rectifier 8 (property to spread). Therefore, the rubber extrudate R can be used as it is sent to the next process of the production line.

  On the other hand, since the flow rate of the rubber R1 is relatively slow at the front end portion of the rectifying body 8, an air A pool is generated on the front surface of the rectifying body 8. Along with this, air A tends to remain at the joining boundary where the rubber R1 temporarily divided by the rectifier 8 is joined. If air A remains in the rubber extrudate R, problems such as swelling and boundary peeling occur in the vulcanized rubber product, and the vulcanization time becomes long.

  In the present invention, in order to solve this problem, the space on the front side of the rectifier 8 and the outside air are communicated with each other through the through passage 10. Then, as illustrated in FIG. 5, the rubber extrudate R is extruded from the extrusion port 6, and the thread member S is continuously discharged from the front surface of the rectifying body 8 through the through passage 10 and continuously embedded in the rubber extrudate R. ing. The thread member S discharged forward from the front surface of the rectifying body 8 is pushed forward together with the rubber extrudate R because the rubber member R1 temporarily divided by the rectifying body 8 is sandwiched between the joining boundaries. Will be.

  The air A accumulated at the front end of the rectifying body 8 enters the through passage 10 from the front surface of the rectifying body 8 by the internal pressure at the die 5. And since the air A is discharged | emitted from the inside of rubber | gum to the exterior (outside air) through the through-passage 10 through which the thread member S has passed, the air A remaining inside the rubber extrudate R can be suppressed.

  Moreover, since the thread member S passes through the through passage 10 and continues to be discharged forward from the front surface of the rectifying body 8, the through passage 10 is not blocked by the rubber R1. Therefore, the air A can be stably discharged through the through passage 10.

  Further, the thread member S extending and embedded in the extrusion direction of the rubber extrudate R is exposed on the end surface of the rubber extrudate R in the extrusion direction. Therefore, even if air A remains in the rubber extrudate R, the air A can be discharged to the outside of the rubber extrudate R through the thread member S embedded in the rubber extrudate R. As a result, the air A remaining inside the rubber extrudate R is suppressed even when compared with the rubber extrudate R extruded by the conventional extruding apparatus illustrated in FIG. It becomes possible to do. In addition, since it becomes easy to take in the air A when the thread member S having a twisted structure is adopted, it is advantageous for discharging the air A remaining inside the rubber extrudate R to the outside.

  When the extending length b of the rectifying body 8 is set to 10 mm or more, distortion in a direction orthogonal to the extrusion direction can be sufficiently applied to the rubber portion that contacts the surface of the rectifying body 8. Therefore, it is advantageous for suppressing the shrinkage of the rubber extrudate R in the extrusion direction. A suitable extension length b is, for example, 10 mm to 50 mm.

  By making the rectifying body 8 into a plate shape, it is possible to prevent the resistance to the rubber R1 passing therethrough from becoming excessive, and thus it becomes easy to extrude the rubber R1 smoothly. The flat plate-like rectifying body 8 is extended in the direction along the extending direction of the extrusion channel 7 so that the plane having a relatively large area faces the inner surface of the extrusion channel 7 having a relatively large area. . For example, in the case of the extrusion channel 7 having a quadrangular cross section, a rectifying body 8 having a quadrangular cross section is used, and in the case of the extrusion channel 7 having a circular cross section, the rectifying body 8 having a circular cross section is used. 7 and the rectifier 8 have the same cross-sectional shape (similar shape).

  If the cross-sectional area of the rectifying body 8 is excessive with respect to the cross-sectional area of the extrusion channel 7, the resistance to rubber becomes excessive, the rubber temperature becomes too high, or an excessive external force acts on the rectifying body 8. Such problems arise. Therefore, the ratio of the cross-sectional area of the rectifier 8 to the cross-sectional area of the extrusion channel 7 is preferably 40% or less, more preferably 5% to 30%, and still more preferably 5% to 20%.

  In the rubber extrudate R extruded from the present invention, the thread member S remains embedded. If the outer diameter and rigidity of the thread member S are not excessive, the rubber extrudate R is vulcanized. The influence of the thread member S can be ignored. In order to ignore the influence of the thread member S on the vulcanized rubber product, the breaking strength of the thread member S should be 100 N or less.

  In this embodiment, one through passage 10 is provided in one rectifier 8, but a plurality of through passages 10 may be provided in one rectifier 8. Then, the thread member S is continuously discharged from the front surface of the rectifier 8 through the respective through passages 10 so as to be embedded in the rubber extrudate R.

  Alternatively, a plurality of rectifying bodies 8 may be provided, and the thread member S may be continuously discharged from the through passage 10 having an opening on the front surface of each rectifying body 8 and embedded in the rubber extrudate R. In this case, the cross-sectional view of the extrusion flow path 7 is arranged such that the maximum separation distance between the surface of the rectifying body 8 and the inner surface of the extrusion flow path 7 and the maximum separation distance between adjacent rectification bodies 8 are 100 mm or less. It is preferable. Specifically, when the extrusion port 6 has a rectangular shape with a width dimension of 300 mm and a height dimension of 50 mm, for example, three rectifier bodies 8 with a width dimension of 10 mm and a height dimension of 5 mm are arranged in the width direction in the extrusion flow path 7. It is preferable that the widthwise interval between each other, the rightmost rectifier 8 and the right inner surface of the extrusion port 6, and the leftmost rectifier 8 and the left inner surface of the extrusion port 6 be equally spaced.

  The embodiment of the rubber extrusion device 1 illustrated in FIG. 6 differs from the previous embodiment only in the position of the tip 8a of the rectifier 8. The front end 8a of the rectifying body 8 is in a position retracted rearward from the front end face of the extrusion port 6 by a retraction length c, and the retraction length c is preferably 10 mm or less.

  In this embodiment, the effect which suppresses the shrinkage | contraction of the extrusion direction of the rubber extrudate R becomes smaller than previous embodiment. On the other hand, it becomes easy to automatically join the split surfaces of the rubber extrudate R temporarily divided by only the swell of unvulcanized rubber divided by the rectifier 8.

  7 and 8 differs from the embodiment illustrated in FIGS. 1 to 3 only in the specifications of the rectifying body 8. In this embodiment, a single plate-like rectifying body 8 is disposed at the center in the width direction of the extrusion port 6 with its thickness direction directed in the width direction of the extrusion port 6. A notch 8 c is formed at a corner below the tip of the rectifier 8.

  The upper end portion of the rectifying body 8 is fixed to the inner surface of the extrusion flow path 7, and the lower end portion of the rectification body 8 is fixed to the inner surface of the extrusion flow path 7 and straddles the extrusion flow path 7 formed in the die 5 and the head 3. It is extended. A gap t in the thickness direction between the extrusion flow path 7 and the rectifier 8 is 0.5 mm or more. That is, the notch 8c is formed in the rectifying body 8, so that a gap t in the thickness direction is provided. The gap t can also be provided on the upper side of the rectifier 8 by forming a notch 8c on the upper side. Alternatively, a pair of notches 8c may be formed on the upper side and the lower side of the rectifying body 8, and the gap t may be provided on the upper side and the lower side.

  The notch 8c is set to a position retracted backward from the front end face of the extrusion port 6 by a length d. In order to reliably integrate the rubber extrudate R immediately after passing through the front end of the rectifying body 8, the retracted length d is preferably set to 1 mm or more.

  The rubber extrudate was extruded using a rubber extrusion apparatus similar to the rubber extrusion apparatus illustrated in FIGS. At this time, the extrusion was carried out by changing the presence or absence of a through passage opening in the front surface of the rectifier. The rectifier is a flat plate, extends 12 mm forward from the position protruding 2 mm forward from the front end surface of the extrusion port, and passes the extruded rubber between the inner surface of the extrusion flow path and the rectifier. The rubber extrudate was extruded from the extrusion port. The ratio of the cross-sectional area of the rectifier to the cross-sectional area of the extrusion channel was about 10%.

  In the rubber extruding apparatus (Example) in which the rectifying body is provided with a through path, the yarn member was continuously discharged from the front surface of the rectifying body through the through path having an inner diameter of 1.5 mm and embedded in the rubber extrudate. As the yarn member, a twisted cotton having an outer diameter of 1 mm was used. When the through-passage is provided in the rectifying body (Example) and not provided (Comparative Example), three types of rubber extrudate samples when the conventional rubber extruding device is removed from the comparative example are extruded. The shrinkage in the extrusion direction was measured by comparing immediately after and when the shrinkage in the extrusion direction was sufficiently subsided. As a result, it was confirmed that the shrinkage rate in the extrusion direction was reduced by about 40% in the examples and comparative examples as compared with the conventional example.

  Moreover, the blow point was confirmed by vulcanizing samples of rubber extrudates of Examples, Comparative Examples, and Conventional Examples. As a result, when the blow point of the conventional example was set to 1.0 (index) as a reference, the comparative example was 1.1 and the example was 0.9. The smaller the value of this index, the shorter the time required for vulcanization, which means that less air remains. Therefore, it can be seen that the embodiment has less air remaining inside the rubber extrudate than the conventional example.

DESCRIPTION OF SYMBOLS 1 Rubber extrusion apparatus 2 Cylinder 3 Head 4 Screw 5 Die 6 Extrusion port 7 Extrusion flow path 8 Rectification body 8a Front end 8b Rear end 8c Notch 9 Connection part 10 Through-path 11 Yarn supply reel 11a Support roller A Air R Rubber extrudate R1 Rubber S Thread member

Claims (10)

In a rubber extrusion device comprising a cylindrical cylinder, a screw arranged in the cylinder, a head installed at the tip of the cylinder, and a die arranged at the tip of the head and having an extrusion port,
A rectifying body extending from the vicinity of the front end face of the extrusion port toward at least the inside of the extrusion flow path of the die toward the cylinder side, and an opening on the front surface of the rectifying body via the inside of the rectification body A through-passage and a thread member passing through the through-passage, wherein the space on the front side of the rectifier and the outside air are in communication with each other through the through-passage, and the inner surface of the extrusion flow channel and the rectifier The rubber extruded by the screw is passed through the gap and the rubber extrudate is pushed out from the extrusion port, and the thread member is continuously discharged forward from the front surface of the rectifier through the through passage. A rubber extrusion device characterized in that it is embedded in an object.   The rubber extrusion device according to claim 1, wherein an extension length of the rectifying body from the front end surface of the extrusion port toward the cylinder is 10 mm or more.   The rubber extruding device according to claim 1, wherein the rectifying body is plate-shaped.   The rubber extrusion device according to any one of claims 1 to 3, wherein a position of a tip of the rectifying body is in a range of 10 mm forward to 10 mm backward from a front end surface of the extrusion port.   The rubber extrusion device according to claim 1, wherein the thread member has a breaking strength of 100 N or less and a twisted structure. A rubber material is put into a cylindrical cylinder, and unvulcanized rubber mixed and kneaded while pushing the rubber material forward by a screw installed in the cylinder is installed at the tip of the cylinder. In a rubber extrusion method of extruding as a rubber extrudate from an extrusion port of a die arranged at the tip of
A rectifier is extended from the vicinity of the front end surface of the extrusion port toward the cylinder side to at least the inside of the extrusion flow path of the die, and an opening is formed in the front surface of the rectifier via the inside of the rectifier. The through-passage is formed, and the space on the front side of the rectifying body is communicated with the outside air through the through-passage, and the unvulcanized rubber extruded forward by the screw is used as the extrusion passage. The rubber extrudate is pushed out from the extrusion port through the gap between the inner surface of the straightener and the rectifying body, and the thread member is continuously discharged from the front surface of the rectifying body through the through passage to the rubber extrudate. A rubber extrusion method characterized by being embedded.   The rubber extrusion method according to claim 6, wherein an extension length from the front end face of the extrusion port of the rectifying body toward the cylinder is 10 mm or more.   The rubber extrusion method according to claim 6 or 7, wherein the rectifying body is formed into a plate shape.   The rubber extrusion method according to any one of claims 6 to 8, wherein a position of a tip of the rectifying body is in a range of 10 mm forward to 10 mm backward from a front end surface of the extrusion port.   The rubber extrusion method according to any one of claims 6 to 9, wherein the yarn member has a breaking strength of 100 N or less and uses a twisted structure.

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