JP6408203B2 - Method and apparatus for removing foreign matter from unvulcanized rubber - Google Patents

Description

  The present invention relates to a foreign matter removal method and apparatus from unvulcanized rubber, and more particularly to a method and apparatus that can efficiently remove foreign matter from unvulcanized rubber without generating new vulcanized rubber foreign matter. It is.

  When manufacturing rubber products such as tires, there are a kneading process in which unvulcanized rubber is kneaded by a kneader and an extrusion process in which unvulcanized rubber is extruded by an extruder. In such a kneading process or an extrusion process, heat is applied to the unvulcanized rubber, so that the vulcanized compounding agent that is blended may act to partially advance the vulcanization reaction. When the vulcanization reaction proceeds excessively, unintended vulcanized rubber foreign matter (burnt particles) is generated in the unvulcanized rubber. Since the vulcanized rubber foreign matter may adversely affect the quality of the rubber product, the unvulcanized rubber mixed with the vulcanized rubber foreign matter has been subject to disposal such as disposal. However, since the portion other than the vulcanized rubber foreign matter is normal unvulcanized rubber, if the vulcanized rubber foreign matter is removed, the remaining normal unvulcanized rubber can be used for manufacturing rubber products. If the vulcanized rubber foreign matter can be removed without as much normal unvulcanized rubber as possible, the material yield is improved. Moreover, since the amount of rubber to be discarded is reduced, it is beneficial from the viewpoint of energy saving and environmental protection.

  Conventionally, as a method of removing foreign matters mixed in unvulcanized rubber, there is known a method in which a strainer is disposed at an extrusion port of an extruder and the unvulcanized rubber extruded through a screen of the strainer is passed (patent) Reference 1). In this method, the size of foreign matter that can be removed is determined by the size of the screen mesh. For this reason, to remove all foreign matter, it is necessary to reduce the screen mesh. This method is originally a method in which unvulcanized rubber is passed through a screen to add additional heat to the unvulcanized rubber. However, if the screen mesh is reduced, more heat is applied. Become. That is, there is a problem that the screen for removing the vulcanized rubber foreign matter makes it easy to generate a new vulcanized rubber foreign matter.

  Therefore, in order to prevent the generation of new vulcanized rubber foreign matter, it is necessary to take measures to reduce the extrusion speed and to apply as little heat as possible to the unvulcanized rubber passing through the screen. However, when the extrusion speed is slowed, the amount of vulcanized rubber foreign matter that can be removed per unit time is reduced, resulting in a problem that efficiency is lowered.

JP 2008-207472 A

  An object of the present invention is to provide a foreign matter removal method and apparatus from unvulcanized rubber that can efficiently remove foreign matter from unvulcanized rubber without generating new vulcanized rubber foreign matter.

  In order to achieve the above object, the method for removing foreign matter from unvulcanized rubber according to the present invention includes a roller head provided with a pair of rotating rollers arranged with a predetermined gap therebetween so that the peripheral surfaces face each other. The unvulcanized rubber which is installed in the mouth and extrudes the unvulcanized rubber mixed with the vulcanized rubber foreign matter by the rubber extruder and rotates the pair of rotating rollers, and the unvulcanized rubber extruded by the rubber extruder is Sheeting is performed by passing through the predetermined gap set smaller than the particle size of the vulcanized rubber foreign matter, and then the widthwise both ends of the sheeted unvulcanized rubber sheet are trimmed.

An apparatus for removing foreign matter from unvulcanized rubber according to the present invention includes a rubber extruder, a roller head installed at an extrusion port of the rubber extruder, and a trim machine arranged downstream of the roller head in the rubber extrusion direction. The roller head includes a pair of rotating rollers arranged with a predetermined gap therebetween and facing the circumferential surfaces, and the predetermined gap is mixed with unvulcanized rubber added to the rubber extruder. A gap adjusting mechanism that adjusts the particle size of the vulcanized rubber foreign matter to be smaller than the particle size of the rubber rubber; The both ends of the vulcanized rubber sheet in the width direction are trimmed by the trim machine.

  According to the present invention, unvulcanized rubber mixed with vulcanized rubber foreign matter is extruded by a rubber extruder, a pair of rotating rollers of a roller head installed at the extrusion port is driven to rotate, and the unvulcanized rubber extruded is Since the sheet is passed through a predetermined gap between the peripheral surfaces of a pair of rotating rollers set smaller than the particle size of the vulcanized rubber foreign matter, the vulcanized rubber foreign matter is directed toward the end of the rotating roller in the width direction. Move. Therefore, by trimming both ends in the width direction of the seated unvulcanized rubber sheet, no vulcanized rubber foreign matter remains on the unvulcanized rubber sheet trimmed at both ends in the width direction. Can be removed.

  In addition, since excessive heat is not applied to the unvulcanized rubber extruded by the rubber extruder during sheeting, generation of new vulcanized rubber foreign matter can be avoided. Moreover, since it is not necessary to slow down the unvulcanized rubber extrusion speed, foreign matters can be efficiently removed from the unvulcanized rubber.

It is explanatory drawing which illustrates the foreign material removal apparatus of this invention by a side view. It is explanatory drawing which illustrates the foreign material removal apparatus of FIG. 1 by planar view. It is explanatory drawing which illustrates typically the motion of the unvulcanized rubber in a roller head by sectional view. It is a graph which illustrates distribution of the extrusion direction pressure of the unvulcanized rubber in a roller head. It is explanatory drawing which illustrates the motion of the vulcanized rubber foreign material before and after passing through the roller head in a plan view.

  Hereinafter, the foreign substance removal method and apparatus from the unvulcanized rubber of the present invention will be described based on the embodiments shown in the drawings.

  A foreign matter removing apparatus 1 of the present invention illustrated in FIGS. 1 and 2 is disposed on a downstream side of a rubber extruder 2, a roller head 3 installed at an extrusion port of the rubber extruder 2, and the roller head 3 in the rubber extrusion direction. The trim machine 9 is provided. As the rubber extruder 2, one having a known specification can be used. The trim machine 9 is installed above the conveying surface of the take-up conveyor 8.

  The roller head 3 has a pair of rotating rollers 4a and 4b arranged with a predetermined gap g therebetween and facing the circumferential surfaces. The rotating rollers 4a and 4b have a simple cylindrical shape. The rotating rollers 4a and 4b are driven to rotate by the drive motor 5, and rotate at a constant rotational speed or by changing the rotational speed in the middle. The predetermined gap g can be set to an arbitrary size by the gap adjusting mechanism 6.

  In this embodiment, a heating means 7 for heating the pair of rotating rollers 4a and 4b is provided. The heating means 7 is for ensuring fluidity so as not to excessively lower the temperature of the unvulcanized rubber R extruded by the rubber extruder 2, and is installed as necessary. As the heating means 7, a heater mechanism that circulates hot water in the rotating roller 4a or the like is used. The heating temperature by the heating means 7 is, for example, about 80 ° C to 100 ° C.

  The trim machine 9 has a pair of circular rotary blades 9a. Each rotary blade 9 a is rotatably supported on a rotary shaft, and the interval between the rotary blades 9 a can be changed by the trim width adjusting mechanism 10. Each of the rotary blades 9 a is arranged so that the blade edge comes into contact with the transport surface of the take-up conveyor 8.

  Next, a procedure for removing the vulcanized rubber foreign matter C mixed in the unvulcanized rubber R using the foreign matter removing apparatus 1 will be described.

  First, the unvulcanized rubber R in which the vulcanized rubber foreign matter C is mixed is put into the rubber extruder 2. The unvulcanized rubber R in which the vulcanized rubber foreign matter C is mixed is generated in the rubber product production line. For example, if this is collected and stored and a certain amount is collected, the foreign matter removing device 1 is used. Then, the vulcanized rubber foreign matter C is removed from the unvulcanized rubber R.

  Here, the predetermined gap g between the peripheral surfaces of the pair of rotating rollers 4a and 4b is set smaller than the particle size of the vulcanized rubber foreign matter C. The size of the vulcanized rubber foreign matter C is about 2 mm to 3 mm corresponding to the outer diameter. Therefore, the predetermined gap g is set to 2 mm or less, or 1.5 mm or less, for example.

  The unvulcanized rubber R put into the rubber extruder 2 becomes soft to some extent (plasticized) and is extruded from the extrusion port. The temperature of the extruded unvulcanized rubber R is, for example, about 50 ° C to 80 ° C. The extruded unvulcanized rubber R is then seated through a predetermined gap g between the rotating pair of rotating rollers 4a and 4b.

  As illustrated in FIG. 3, when viewed in a cross-sectional view of the roller head 3, when the unvulcanized rubber R is sandwiched between the pair of rotating rollers 4 a and 4 b and seated, the peripheral surfaces of the rotating rollers 4 a and 4 b. There is a rubber R2 that does not flow easily in contact with the rubber and other rubber R1 that easily flows. That is, when the unvulcanized rubber R comes into contact with the peripheral surfaces of the rotating rollers 4a and 4b, the rubber R2 is in close contact with the peripheral surfaces and cannot move. Layers are formed. Rubber R1 that is easy to flow is present at a position further away from the peripheral surfaces of the rotating rollers 4a and 4b.

  Further, as viewed in a plan view of the roller head 3, as illustrated in FIG. 4, the pressure distribution in the extrusion direction of the unvulcanized rubber R in the roller head 3 is relative to the central portion in the roller width direction of the rotating rollers 4a and 4b. The both ends in the roller width direction become relatively low. Therefore, the rubber R1 that is easy to flow passes through the predetermined gap g in the central portion in the roller width direction where the extrusion pressure is relatively high. That is, the rubber R1 that easily flows flows sequentially in the central portion in the roller width direction, and a large amount of the rubber R1 that easily flows passes through the predetermined gap g in the central portion in the roller width direction.

  On the other hand, the vulcanized rubber foreign matter C is harder than the unvulcanized rubber R and has a certain shape, and therefore has a lower fluidity than the unvulcanized rubber R. Further, since the predetermined gap g is set to be smaller than the particle size of the vulcanized rubber foreign matter C, the vulcanized rubber foreign matter C cannot smoothly pass through the predetermined gap g. Therefore, the vulcanized rubber foreign matter C tends to move together with the rubber R2 which does not flow easily, without riding on the rubber R1 which easily flows. Therefore, as illustrated in FIG. 5, the vulcanized rubber foreign matter C moves to both ends in the roller width direction and passes through the predetermined gap g.

  Next, both ends in the width direction of the unvulcanized rubber sheet S sheeted through the predetermined gap g are trimmed with the predetermined trim width W1 by the rotary blade 9a. As described above, since the vulcanized rubber foreign matter C is moving toward both ends in the roller width direction, trimming the both ends in the width direction of the unvulcanized rubber sheet S by the trim machine 9 allows the unvulcanized rubber to be trimmed. The portion of the sheet S that remains without being trimmed (portion other than both ends in the roller width direction) is in a state in which the vulcanized rubber foreign matter C is removed.

  The preferable trim width W1 varies depending on the total width W of the unvulcanized rubber sheet S. For example, the trim width W1 is in the range of 5 mm or more in the width direction from the end in the width direction of the unvulcanized rubber sheet S and 10% or less of the total width W. To do. By setting the trim width W1 within this range, it is advantageous to remove the vulcanized rubber foreign matter C without leaving the normal unvulcanized rubber R as much as possible. The total width W of the unvulcanized rubber sheet S is, for example, 200 mm to 400 mm. The dimension of the trim width W1 can be adjusted by changing the position of the rotary blade 9a using the trim width adjusting mechanism 10.

  As described above, since the unvulcanized rubber R only passes through the predetermined gap g between the pair of rotating rollers 4a and 4b at the time of sheeting, excessive heat is applied to the unvulcanized rubber R extruded by the rubber extruder 2. There is no participation. Therefore, generation of new vulcanized rubber foreign matter C can be avoided. Further, unlike the conventional method using a strainer for removing foreign matter, it is not necessary to slow down the extrusion speed of the unvulcanized rubber R in order to prevent the generation of new vulcanized rubber foreign matter C. It is advantageous for efficiently removing the vulcanized rubber foreign matter C from the slag.

  In order to secure a certain amount of the unvulcanized rubber R obtained by removing the vulcanized rubber foreign matter C per unit time, the predetermined gap g between the pair of rotating rollers 4a and 4b may be set to 0.5 mm or more. According to the present invention, not only the vulcanized rubber foreign matter C but also a foreign matter having a particle size larger than the predetermined gap g has moved to the end in the width direction of the unvulcanized rubber sheet S. Therefore, by trimming both ends in the width direction of the unvulcanized rubber sheet S with the trim machine 9, foreign matters other than the vulcanized rubber foreign matter C can be removed.

  Since the unvulcanized rubber sheet S from which the vulcanized rubber foreign matter C has been removed can be used for the production of rubber products, the yield of the rubber material is improved. Since it is a trimmed portion where the vulcanized rubber foreign matter C is mixed, the amount of discarded rubber is reduced, which is beneficial for energy saving and environmental protection.

  When the unvulcanized rubber R is allowed to pass through the predetermined gap g, the fluidity of the unvulcanized rubber R increases when the pair of rotating rollers 4a and 4b is heated by the heating means 7. Therefore, the amount obtained per unit time of the unvulcanized rubber R from which the vulcanized rubber foreign matter C is removed can be increased. However, the temperature of the heated unvulcanized rubber R is set to 120 ° C. or less, for example, so that no new vulcanized rubber foreign matter C is generated.

DESCRIPTION OF SYMBOLS 1 Foreign material removal apparatus 2 Rubber extruder 3 Roller head 4a, 4b Rotating roller 5 Drive motor 6 Gap adjustment mechanism 7 Heating means 8 Take-up conveyor 9 Trim machine 9a Rotary blade 10 Trim width adjustment mechanism C Vulcanized rubber foreign material R Unvulcanized Rubber R1 Rubber that flows easily R2 Rubber that does not flow easily S Unvulcanized rubber sheet

Claims (9)

  A roller head equipped with a pair of rotating rollers arranged with a predetermined gap facing each other and facing each other is installed at the extrusion port of the rubber extruder, and this rubber extruder is used to unvulcanize the vulcanized rubber foreign matter. While extruding rubber, the pair of rotating rollers are driven to rotate, and the unvulcanized rubber extruded by the rubber extruder passes through the predetermined gap set smaller than the particle size of the vulcanized rubber foreign matter. And then trimming both ends in the width direction of the sheeted unvulcanized rubber sheet.   The method for removing foreign matter from unvulcanized rubber according to claim 1, wherein the predetermined gap is set to 2 mm or less.   The unvulcanized rubber according to claim 1 or 2, wherein a range of 5 mm or more in the width direction from the end in the width direction of the sheeted unvulcanized rubber sheet and 10% or less of the entire width of the unvulcanized rubber sheet is trimmed. Foreign matter removal method from   The method for removing foreign matter from unvulcanized rubber according to any one of claims 1 to 3, wherein when the unvulcanized rubber is passed through the predetermined gap, the pair of rotating rollers is heated. A rubber extruder, a roller head installed at the extrusion port of the rubber extruder, and a trim machine disposed downstream of the roller head in the rubber extrusion direction, the roller head being circumferentially spaced with a predetermined gap. It has a pair of rotating rollers arranged with their faces facing each other, and the predetermined gap is adjusted to be smaller than the particle size of the vulcanized rubber foreign matter mixed in the unvulcanized rubber charged into the rubber extruder. A gap adjusting mechanism is provided, and both end portions in the width direction of the unvulcanized rubber sheet that is extruded by the rubber extruder and passed through a predetermined gap between the pair of rotational rollers that are driven to rotate are seated by the trim machine. An apparatus for removing foreign matter from unvulcanized rubber, characterized by trimming.   The apparatus for removing foreign matter from unvulcanized rubber according to claim 5, wherein the predetermined gap is set to 2 mm or less.   The range in which the sheeted unvulcanized rubber sheet is trimmed is set to a range of 5 mm or more in the width direction from the width direction end of the unvulcanized rubber sheet and 10% or less of the total width of the unvulcanized rubber sheet. An apparatus for removing foreign matter from unvulcanized rubber according to claim 5 or 6.   The apparatus for removing foreign matter from unvulcanized rubber according to any one of claims 5 to 7, further comprising heating means for heating the pair of rotating rollers. The apparatus for removing foreign matter from unvulcanized rubber according to any one of claims 5 to 8 , further comprising a trim width adjusting mechanism for adjusting a range in which the sheeted unvulcanized rubber sheet is trimmed.

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