JP6187031B2 - 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 is a method of supplying unrolled rubber by plasticizing a pair of rolls arranged with a predetermined gap therebetween and facing the peripheral surfaces. It is arranged at the rubber supply destination of the supply machine, and the rubber supply machine supplies unvulcanized rubber mixed with foreign vulcanized rubber, and the pair of rolls are driven to rotate so that the unvulcanized rubber supplied by the rubber supply machine is supplied. While the vulcanized rubber is passed through the predetermined gap and wound around the entire circumference of one of the rolls, the pair of rolls are continuously driven to rotate, and a part of the surface side of the unvulcanized rubber wound around the one roll Is removed from the one roll and continuously taken out, whereby the vulcanized rubber foreign matter is wound around the bank rubber between the pair of rolls or the entire circumference of the one roll. Characterized in that to stay in the vulcanized rubber.

  An apparatus for removing foreign matter from unvulcanized rubber according to the present invention includes a rubber feeder that plasticizes and supplies unvulcanized rubber, a pair of rolls installed at a rubber supply destination of the rubber feeder, and the pair of rolls The pair of rolls are arranged with a predetermined gap therebetween so that their peripheral surfaces face each other, supplied by the rubber feeder, and driven to rotate. A part of the surface side of the unvulcanized rubber that passes through a predetermined gap between the pair of rolls and is wound around the entire circumference of the one roll is peeled off from the one roll and is continuous. The vulcanized rubber foreign matter is retained in the bank rubber between the pair of rolls or in the unvulcanized rubber wound around the entire circumference of the one roll by being taken up by a take-off machine. To do.

  According to the present invention, plasticized unvulcanized rubber in which vulcanized rubber foreign matter is mixed is supplied by a rubber feeder, and a pair of rolls installed at a rubber supply destination are driven to rotate to supply the unvulcanized rubber. Is passed through a predetermined gap between the peripheral surfaces of the pair of rolls, and the pair of rolls are continuously rotated while being wound around the entire circumference of the one roll, and the unvulcanized rubber wound around the one roll. The vulcanized rubber foreign matter is wound around the bank rubber between the pair of rolls or the entire circumference of the one roll. Since the unvulcanized rubber is retained, the vulcanized rubber foreign matter does not remain in the unvulcanized rubber that has been taken off, and the vulcanized rubber foreign matter can be removed.

  And when passing a predetermined gap of a pair of rolls, since excessive heat is not applied to unvulcanized rubber, generation of new vulcanized rubber foreign matter can be avoided. Further, since no strainer is disposed, it is not necessary to slow down the supply speed of the unvulcanized rubber by the rubber feeder, and 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 the motion of the unvulcanized rubber with a pair of roll by a cross sectional view. It is a front view which illustrates one roll. It is a front view of one roll which shows the modification of a groove | channel. It is a front view of one roll which shows the modification of a groove | channel. It is a front view of one roll which shows the modification of a groove | channel. It is explanatory drawing which illustrates the roll width direction cross-sectional shape of a groove | channel.

  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 includes a rubber feeder 2, a pair of rolls 3 and 4 installed at a rubber supply destination of the rubber feeder 2, and the pair of rolls 3 and 4 And a rubber take-up machine 8 disposed in the vicinity. The rubber feeder 2 is a machine that can plasticize and supply the unvulcanized rubber R. For example, a known rubber extruder, roll kneader, or the like can be used. As the rubber take-up machine 8, a take-up conveyor 8 can be used as exemplified in the embodiment.

  The pair of rolls 3 and 4 are arranged such that their circumferential surfaces face each other with a predetermined gap g. Each of the rolls 3 and 4 has a cylindrical shape and is rotated by a drive motor 6 and rotates at a constant rotation speed or by changing the rotation speed in the middle. The predetermined gap g can be set to an arbitrary size by the gap adjusting mechanism 6a.

  In this embodiment, a heating means 7 for heating the pair of rolls 3 and 4 is provided. The heating means 7 is for ensuring the fluidity of the unvulcanized rubber R so as not to excessively lower the temperature of the unvulcanized rubber R supplied by the rubber feeder 2, and as necessary. Install. As the heating means 7, a heater mechanism for circulating hot water in the rolls 3 and 4 is used. The temperature of the unvulcanized rubber R supplied by the rubber feeder 2 is, for example, about 50 ° C. to 80 ° C., and the heating temperature by the heating means 7 is, for example, about 50 ° C. to 100 ° C.

On the conveying surface of the take-up conveyor 8, the surface side of the unvulcanized rubber R that passes through a predetermined gap g between the pair of rotationally driven rolls 3 and 4 and is wound around the entire circumference of the one roll 3. The part is placed as a belt-like rubber sheet S. Then, by running the take-up conveyor 8, the belt-like rubber sheet S in which a part of the surface side of the unvulcanized rubber R is peeled off from the one rotary roll 3 and is made continuous is taken up by 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, unvulcanized rubber R in which vulcanized rubber foreign matter C is mixed is put into the rubber feeder 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 rolls 3 and 4 is set to a size equivalent to the particle size of the vulcanized rubber foreign matter C, or about 0.5 m. The size of the vulcanized rubber foreign matter C to be removed is, for example, about 1 mm to 3 mm corresponding to the outer diameter. The predetermined gap g is set to 2 mm or less, for example.

  The unvulcanized rubber R put into the rubber feeder 2 is softened to some extent (plasticized) and supplied from the rubber supply destination. The supplied unvulcanized rubber R is then seated through a predetermined gap g between the pair of rotating rolls 3 and 4.

  As illustrated in FIG. 3, when the pair of rolls 3, 4 is viewed in a cross-sectional view, when the unvulcanized rubber R is sandwiched between the pair of rolls 3, 4 and seated, the pair of rolls 3, 4 A predetermined amount of bank rubber BR exists above the space between the two. As an initial setting, the unvulcanized rubber R is wrapped around the entire circumference of only one roll 3. Thus, when the pair of rolls 3 and 4 are rotationally driven to pass the unvulcanized rubber R through the predetermined gap g, the unvulcanized rubber R is wound around only one roll 3.

  Then, a part of the surface side of the unvulcanized rubber R wound around one roll 3 is peeled off from the roll 3 as a continuous belt-like rubber sheet S and placed on the conveying surface of the take-up conveyor 8. The rubber thickness of the rubber sheet S taken up by the take-up conveyor 8 is, for example, about 50% of the predetermined gap g. As illustrated in FIG. 2, the rubber supply destination of the rubber feeder 2 is set to one side in the roll width direction of the pair of rolls 3 and 4, and the position where the rubber sheet S is peeled off from the roll 3 is a pair of rolls. It is good to make the position of the other in the roll width direction of 3 and 4 offset each other.

  Here, the roll 3 includes a rubber R <b> 2 that is difficult to flow and is in contact with the circumferential surface of the roll, and another rubber R <b> 1 that is easy to flow. That is, when the unvulcanized rubber R comes into contact with the peripheral surface of the roll 3, the rubber R2 hardly adheres to the peripheral surface of the roll 3 and the vicinity thereof. . Rubber R1 that is easy to flow is present at a position further away from the peripheral surface of the roll 3 in the radial direction. The layer of the rubber R1 which is easy to flow is made into a continuous belt-like rubber sheet S and is peeled off from the roll 3 and is taken up by the take-up conveyor 8.

  That is, the pair of rolls 3 and 4 are driven to rotate, and the pair of rolls 3 and 4 are driven to rotate while the unvulcanized rubber R passes through the predetermined gap g and is wound around the entire circumference of the one roll 3. In addition, the take-up conveyor 8 is run and the rubber sheet S is peeled off from the roll 3 and taken up in a continuous state. Here, the vulcanized rubber foreign matter C having a particle size somewhat larger than the predetermined gap g cannot pass through the predetermined gap g. Therefore, the large vulcanized rubber foreign matter C stays in the bank rubber BR.

  On the other hand, the vulcanized rubber foreign matter C having a particle size equal to or smaller than the predetermined gap g passes through the predetermined gap g. However, since the vulcanized rubber foreign matter C is harder than the unvulcanized rubber R and has a certain shape, the fluidity is lower than that of the unvulcanized rubber R. The rubber R1 that is easy to flow flows from the one side in the roll width direction of the roll 3 (the rubber supply destination by the rubber feeder 2) toward the other side (the position at which the rubber sheet S is peeled off). Since the fluidity is low, the rubber R1 which tends to flow does not get on and tends to stay in the layer of the rubber R2 which does not flow easily. Therefore, the small vulcanized rubber foreign matter C that has passed through the predetermined gap g tends to stay in the unvulcanized rubber R that is wound around the entire circumference of the roll 3. Accordingly, the rubber sheet S taken up by the take-up conveyor 8 is in a state in which most of the vulcanized rubber foreign matter C remains and is largely removed.

  Since the 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. The target for disposal is the bank rubber BR that exists after the foreign substance removal process is completed and the unvulcanized rubber R that is wound around the entire circumference of the roll 3, so the amount of discarded rubber is reduced, which is beneficial for energy saving and environmental protection. is there. Since the amount of the unvulcanized rubber R wound around the entire circumference of the bank rubber BR and the roll 3 is substantially constant regardless of the amount of the unvulcanized rubber R that removes foreign matter, the unvulcanized rubber R that removes foreign matter. As the amount increases, the rubber material yield improves.

  As described above, since the unvulcanized rubber R only passes through the predetermined gap g between the pair of rolls 3 and 4 at the time of sheeting, excessive heat is applied to the unvulcanized rubber R supplied by the rubber feeder 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 supply rate 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 (rubber sheet S) obtained by removing the vulcanized rubber foreign matter C per unit time, the predetermined gap g between the pair of rolls 3 and 4 is set to 0.5 mm or more. It is good to set. According to the present invention, not only the vulcanized rubber foreign matter C but also other foreign matters can be removed.

  When the unvulcanized rubber R is passed through the predetermined gap g, if the pair of rolls 3 and 4 are heated by the heating means 7, the fluidity of the unvulcanized rubber R is increased. 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. If the temperature of the unvulcanized rubber R is low and the fluidity is too low, the unvulcanized rubber R wound around the roll 3 may be peeled off from the roll peripheral surface when entering the predetermined gap g. Further, when the unvulcanized rubber R having low fluidity passes through the predetermined gap g, an excessive pressure is applied to the rolls 3 and 4 to widen the predetermined gap g, or the roll shaft is deformed. It can cause problems. For this reason, it is necessary to impart appropriate plasticity to the unvulcanized rubber R that allows the predetermined gap g to pass therethrough. 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.

  In the above embodiment, simple cylindrical rolls 3 and 4 are used, but as illustrated in FIGS. 4 to 7, grooves 5 are provided on the peripheral surface of one roll 3 around which unvulcanized rubber is wound. You can also. As illustrated in FIG. 8, the groove 5 is formed to have a large groove depth from one side in the roll width direction (a rubber supply destination by the rubber feeder 2) to the other side (a position where the rubber sheet S is peeled off). The groove width of the groove 5 is, for example, 2 mm to 50 mm, and the maximum groove depth d is, for example, 1 mm to 2 mm. Then, the rubber sheet S is peeled off at a position on the other side in the roll width direction from the groove 5 and taken up.

  The range in which the grooves 5 are provided is, for example, about 2/3 of the full width of the roll 3. In the range of 1/3 of the remaining full width, the groove 5 is not formed in order to peel off the rubber sheet S.

  Various forms can be adopted as the groove 5. An annular groove 5 extending in the circumferential direction of the roll 3 as exemplified in FIG. 4 and a spiral groove 5 as exemplified in FIG. 5 can be used. Alternatively, a groove 5 that is partially divided in the circumferential direction of the roll 3 as illustrated in FIG. 6 and extended in the circumferential direction, or intermittent at a predetermined pitch in the circumferential direction of the roll 3 as illustrated in FIG. It is also possible to use the grooves 5 arranged in the. In addition, in the groove | channel 5 illustrated in FIG. 7, not only rectangular shape by planar view but arbitrary shapes, such as circular shape and an ellipse shape, are employable.

  As illustrated in FIGS. 4 to 7, when the groove 5 that increases the groove depth from one side to the other side in the roll width direction is formed on the circumferential surface of the roll 3, the roll 3 is wound around the rotating roll 3. The rubber R1 that is easy to flow of the unvulcanized rubber R flows from one side to the other side in the roll width direction. Since the rubber R2 which does not flow easily forms a layer at the bottom of the groove 5, the vulcanized rubber foreign matter C easily moves to the bottom of the groove. In the groove 5, the rolling force received from the rolls 3 and 4 when the unvulcanized rubber R passes between the pair of rolls 3 and 4 increases as the groove depth is shallower. Due to the difference in rolling force, a flow of the unvulcanized rubber R is generated from the shallower groove depth toward the deeper groove 5. Therefore, the vulcanized rubber foreign matter C having a small particle diameter that has passed through the predetermined gap g tends to move and stay in the deep part on the other side of the groove 5 in the roll width direction.

  That is, while continuing to rotationally drive the pair of rolls 3 and 4, the unvulcanized rubber R supplied by the rubber feeder 2 is passed through the predetermined gap g and wound around the entire circumference of the one roll 3. At a position on the other side of the groove 5 in the roll width direction, a part of the surface side of the unvulcanized rubber R wound around the roll 3 is pulled off from the roll 3 and continuously taken up. Thereby, the vulcanized rubber foreign matter C that is somewhat larger than the predetermined gap g can be retained in the bank rubber BR. The vulcanized rubber foreign matter C having the same size as or smaller than the predetermined gap g can be retained in the unvulcanized rubber R (in the groove 5) wound around the entire circumference of the roll 3.

  In the case of the groove 5 illustrated in FIGS. 5 and 6, it is preferable to provide a plurality of grooves 5 that are separated from each other in the roll width direction. Furthermore, it is preferable that a plurality of grooves 5 provided in the roll width direction are arranged without gaps in the roll circumferential direction in a side view of the roll (view viewed from one side of the roll width direction to the other side). This makes it easy for the vulcanized rubber foreign matter C to remain in the groove 5 without remaining, which is advantageous for removing the vulcanized rubber foreign matter C from the unvulcanized rubber R. When a plurality of grooves 5 are provided apart from each other in the roll width direction, the rubber sheet S is peeled off at a position on the other side in the roll width direction from the groove 5 at the other end in the roll width direction. To do.

  With respect to 200 kg of unvulcanized rubber mixed with vulcanized rubber foreign matter, vulcanized rubber foreign matter was removed using the foreign matter removing apparatus shown in FIGS. That is, the unvulcanized rubber extruded by the rubber extruder passes through the predetermined gap g of the pair of rolls, and continues to rotationally drive the pair of rolls while being wound around the entire circumference of the one roll. A part of the surface side of the unvulcanized rubber wound around the roll was peeled off from one of the rolls and continuously taken out. The predetermined gap g was set to 1 mm. The temperature of the unvulcanized rubber extruded by the rubber extruder was 60 ° C. to 80 ° C., and the rubber temperature during the treatment was maintained in this temperature range. The unvulcanized rubber was mixed with a quantity of vulcanized rubber foreign matter having a particle diameter of 1 to 10 mm as shown in Table 1.

  In Example 1, as a pair of rolls, simple cylindrical rolls having no grooves on the peripheral surfaces were used. In Example 2, as shown in FIG. 4, four annular grooves continuous on the entire circumference in the circumferential direction were formed on the circumferential surface of one roll around which unvulcanized rubber was wound. The groove width of each groove is 10 mm, the groove depth is deeper from one side to the other side in the roll width direction, and the maximum groove depth is 1 mm.

  After finishing the removal treatment of the vulcanized rubber foreign matter, the number of staying of the vulcanized rubber foreign matter C in the bank rubber is confirmed for Example 1, and the number of staying of the vulcanized rubber foreign matter C in the bank rubber and the groove is confirmed for Example 2. Table 1 shows the confirmed number of stays.

  From the results in Table 1, it can be seen that in Example 1, most of the vulcanized rubber foreign matter somewhat larger than the predetermined gap g (1 mm) of the pair of rolls stays in the bank rubber, and most of the vulcanized rubber foreign matter can be removed. In Example 2, it can be seen that vulcanized rubber foreign matter smaller than the predetermined gap g stays in the groove, and all vulcanized rubber foreign matter can be removed.

DESCRIPTION OF SYMBOLS 1 Foreign material removal apparatus 2 Rubber feeder 3, 4 Roll 5 Groove 6 Drive motor 6a Gap adjustment mechanism 7 Heating means 8 Take-out conveyor (rubber take-up machine)
C Foreign matter of vulcanized rubber R Unvulcanized rubber R1 Rubber that easily flows R2 Rubber that hardly flows S S Unvulcanized rubber sheet

Claims (11)

  A pair of rolls arranged with a predetermined gap between them and facing each other are arranged at a rubber supply destination of a rubber supply machine that plasticizes and supplies unvulcanized rubber. While supplying mixed unvulcanized rubber, the pair of rolls are driven to rotate, and the unvulcanized rubber supplied by the rubber feeder is passed through the predetermined gap and wound around the entire circumference of one roll. By continuing to rotationally drive the pair of rolls while being in a state where a part of the surface side of the unvulcanized rubber wound around the one roll is peeled off from the one roll and continuously taken, Foreign matter removal from unvulcanized rubber, characterized in that vulcanized rubber foreign matter stays in bank rubber between said pair of rolls or unvulcanized rubber wound around the entire circumference of said one roll .   A groove that increases the groove depth from one side of the roll width direction to the other side is formed on the peripheral surface of the one roll, and is wound around the one roll at a position on the other side of the roll width direction than the groove. The method for removing foreign matter from unvulcanized rubber according to claim 1, wherein a part of the surface of the unvulcanized rubber is peeled off from the one roll to cause the vulcanized rubber foreign matter to stay in the groove.   The foreign material removal method from the unvulcanized rubber according to claim 2, wherein the groove is formed in an annular shape or a spiral shape by extending in the circumferential direction of the one roll.   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 method for removing foreign matter from unvulcanized rubber according to any one of claims 1 to 4, wherein when the unvulcanized rubber is passed through the predetermined gap, the pair of rotating rolls is heated.   Comprising a rubber feeder for plasticizing and supplying unvulcanized rubber, a pair of rolls installed at a rubber supply destination of the rubber feeder, and a rubber take-up machine arranged in the vicinity of the pair of rolls, The pair of rolls are arranged with a predetermined gap therebetween so that their peripheral surfaces face each other, and are supplied by the rubber feeder and pass through the predetermined gap between the pair of rolls that are rotationally driven. The surface of the unvulcanized rubber that is in a state of being wound around the entire circumference of the rubber is taken off from one of the rolls and continuously taken out by the rubber take-off machine, thereby removing the vulcanized rubber foreign matter. An apparatus for removing foreign matter from unvulcanized rubber, wherein the apparatus is configured to stay in bank rubber between a pair of rolls or unvulcanized rubber wound around the entire circumference of the one roll.   A groove that increases the groove depth from one side of the roll width direction to the other side is formed on the peripheral surface of the one roll, and is wound around the one roll at a position on the other side of the roll width direction than the groove. The apparatus for removing foreign matter from unvulcanized rubber according to claim 6, wherein a part of the surface side of the unvulcanized rubber is pulled off from one of the rolls and taken up by the rubber take-up machine in a continuous state. .   The foreign matter removing device from unvulcanized rubber according to claim 7, wherein the groove is an annular groove or a spiral groove extending in a circumferential direction of the one roll.   The apparatus for removing foreign matter from unvulcanized rubber according to any one of claims 6 to 8, wherein the predetermined gap is set to 2 mm or less.   The apparatus for removing foreign matter from unvulcanized rubber according to any one of claims 6 to 9, further comprising a heating means for heating the pair of rolls.   The foreign matter removing apparatus from unvulcanized rubber according to any one of claims 6 to 10, further comprising a gap adjusting mechanism for adjusting the predetermined gap.

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