JP7131249B2 - Tire sheet manufacturing equipment - Google Patents

Description

The present invention relates to a sheet manufacturing apparatus used for manufacturing tires.

In the manufacture of tires, a band-like sheet made of unvulcanized rubber or unvulcanized rubber with embedded cords is prepared in the molding process. This sheet is cut to size and wound onto a drum or rigid core. As a result, tire components such as an inner liner and a carcass are formed.

In a typical sheet production, hot unvulcanized rubber is rolled into a sheet in a rolling mill. This sheet-like unvulcanized rubber (uncooled sheet) is cooled by a cooler to obtain a sheet. In order to suppress variations in sheet dimensions due to contraction of the rubber during cooling, the uncooled sheet is quickly cooled by being moved, for example, on a plurality of cooling drums in a cooler. This sheet is wound around a roller and stored, or sent to the next step as it is. A study on a sheet manufacturing method is disclosed in JP-A-2008-137361.

Japanese Patent Application Laid-Open No. 2008-137361

Improving the adhesive strength of the sheet and reducing variations in the adhesive strength are important for improving the productivity and quality of tires. The adhesive force of the sheet and its variation depend on the temperature of the sheet obtained by cooling and the variation of this temperature. This is because the sheet releases heat even while the sheet is wound and stored, and sulfur, stearic acid, etc. added to the unvulcanized rubber precipitate on the surface of the sheet. Insufficient cooling can increase the amount of precipitates and reduce adhesion. Variation in the temperature of the sheet when cooled can be a factor in variation in adhesive strength of the sheet. On the other hand, excessive cooling or the introduction of a complicated temperature control mechanism can lead to an increase in manufacturing costs. There is a need for a sheet manufacturing apparatus that can accurately control the temperature of a sheet with a simple mechanism, thereby obtaining a sheet with good adhesive strength and suppression of variations in adhesive strength at low cost.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet manufacturing apparatus capable of obtaining a sheet having good adhesive strength and suppressing variations in adhesive strength at low cost.

The present invention relates to a sheet manufacturing apparatus used in a tire molding process. This apparatus comprises a rolling mill for forming a belt-shaped uncooled sheet from hot unvulcanized rubber, and a cooler for cooling the uncooled sheet to obtain a sheet. The cooler includes a plurality of cooling drums in which cooling liquid flows, and connecting pipes connecting the cooling drums. A cooling liquid flow path is formed by the cooling drum and the connecting pipe. The uncooled sheet is moved over these cooling drums in sequence from the downstream cooling drum to the upstream cooling drum.

Preferably, the flow rate of the coolant flowing through the flow path is 200 L/min or more and 600 L/min or less.

Preferably, the apparatus further comprises a clarifier for removing foreign matter in the coolant.

Preferably, the apparatus further comprises a sterilizer for sterilizing the coolant.

Preferably, the device further comprises a monitor for monitoring the quality of the coolant.

TECHNICAL FIELD The present invention relates to a method for manufacturing a sheet used in a tire molding process. This method
A process of forming an uncooled sheet from high-temperature unvulcanized rubber, and a cooler in which a single cooling liquid flow path is formed by a plurality of cooling drums in which cooling liquid flows and connecting pipes connecting these drums. and cooling the uncooled sheet by sequentially moving the uncooled sheet from a cooling drum located downstream of the flow path toward a cooling drum located upstream of the flow path, on these cooling drums.

In this device, a plurality of cooling drums of a cooler are connected by connecting pipes to form one cooling liquid flow path. In this device, the same flow rate of cooling liquid always flows stably to all the cooling drums. This contributes to the reduction of sheet temperature variations. In this apparatus, the uncooled sheet is moved over the cooling drums in sequence from the downstream cooling drum to the upstream cooling drum. In this device, the cooling liquid in the cooling drum positioned furthest upstream in the flow path is hardly affected by the heat of the uncooled sheet. Uncooled sheets are finally cooled on this cooling drum. This makes it possible to obtain sheets of a given temperature. With this apparatus, it is possible to obtain a sheet having good adhesive strength and reduced variation in adhesive strength. This device does not have a complicated control mechanism for increasing the accuracy of sheet temperature control. The mechanism of this device is simple. This contributes to cost reduction.

FIG. 1 is a conceptual diagram showing a sheet manufacturing apparatus according to the present invention. 2 is a sectional view showing a part of the manufacturing apparatus of FIG. 1. FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

FIG. 1 is a conceptual diagram showing a sheet manufacturing apparatus 2 according to the present invention. In FIG. 1, the direction indicated by the arrow X is forward, and the opposite direction is backward. The vertical direction is the direction perpendicular to the plane of the paper. FIG. 2 is a cross-sectional view showing part of the device 2 shown in FIG. In FIG. 2, the direction indicated by the arrow X is forward, and the opposite direction is backward. The direction indicated by the arrow Z is upwards and the opposite is downwards. This apparatus 2 comprises a mill 4 , a cooler 6 , a clarifier 8 , a sterilizer 10 and a monitor 12 .

This device 2 forms a sheet from hot unvulcanized rubber. This unvulcanized rubber 14 and sheet 16 are also shown in FIGS. Unvulcanized rubber 14 is supplied to the apparatus 2 from, for example, an extruder. The temperature of the unvulcanized rubber 14 is typically 60°C to 90°C. This unvulcanized rubber 14 contains 5 to 10 phr of sulfur. The temperature of the formed sheet 16 is typically 20°C to 30°C.

The rolling mill 4 has a pair of calender rolls 18 . These calender rolls 18 rotate in the direction of the arrow in FIG. By this rotation, the supplied unvulcanized rubber 14 is passed between these calender rolls 18 . As a result, the unvulcanized rubber 14 is rolled and formed into a belt shape. In this embodiment, this results in strip-shaped uncooled sheets 20 . The gap between calender rolls 18 can be set to any desired value. An uncooled sheet 20 having a desired thickness is thereby obtained.

The cooler 6 comprises a cooling drum 22 and a connecting pipe 24 . As shown in FIGS. 1 and 2, a plurality of cooling drums 22 are arranged side by side. As shown in FIG. 2, in this embodiment, ten cooling drums 22 are alternately arranged, five on each of the upper and lower stages. As shown in FIG. 2, when the cooler 6 is viewed from above, the cooling drums 22 arranged in the upper stage and the cooling drums 22 arranged in the lower stage overlap in the front-rear direction. In FIG. 1, the cooling drums 22 are drawn so as not to overlap each other for easy viewing.

Each cooling drum 22 is cylindrical. The interior of the cooling drum 22 is hollow. A cooling liquid 26 flows inside the cooling drum 22 . A typical coolant 26 is water. As shown in FIG. 2, uncooled sheet 20 is in contact with the outer peripheral surface of cooling drum 22 . The cooling drum 22 can rotate in the direction of the arrow in FIG. This rotation moves the uncooled sheet 20 over the cooling drum 22 . The uncooled sheet 20 is moved while contacting the outer peripheral surface of the cooling drum 22 .

The connection pipe 24 connects between the cooling drums 22 . The interior of the connecting pipe 24 is hollow. A cooling liquid 26 flows inside the connection pipe 24 .

The inlet of the cooling liquid 26 of the cooler 6 is indicated by reference numeral I in FIG. A cooling liquid 26 enters from one end of the cooling drum 22 located at the rearmost position. The other end of this cooling drum 22 is connected to one end of the adjacent cooling drum 22 (second cooling drum 22 from the rear) by a connecting pipe 24 . The other end of the second cooling drum 22 from the rear is connected to one end of the third cooling drum 22 from the rear by a connecting pipe 24 . In this manner, all cooling drums 22 are connected in series by connecting tubes 24 . The outlet of the cooling liquid 26 of the cooler 6 is indicated by the symbol O in FIG. The cooling drum 22 and the connecting pipe 24 form a flow path for the cooling liquid 26 that is connected from the inlet I to the outlet O. As shown in FIG.

1, the connecting pipe 24 is drawn thinner than the cooling drum 22 for easy viewing. In practice, the connecting tube 24 has sufficient thickness to ensure the required flow rate. For example, the inner diameter of the connecting pipe 24 is the same as the inner diameter of the cooling drum 22 .

A clarifier 8 is located upstream of the inlet I of the cooler 6 . Purifier 8 removes suspended matter in coolant 26 . In this embodiment the clarifier 8 comprises a mesh strainer.

The sterilizer 10 is located upstream of the inlet I of the cooler 6 . The sterilizer 10 sterilizes the coolant 26 to prevent biofilm from occurring in the coolant 26 . In this embodiment, sterilizer 10 is an ultraviolet irradiator.

The monitor 12 is located downstream of the outlet O of the cooler 6 . The monitor 12 monitors the liquid quality of the coolant 26 . Monitor 12 measures the amount of suspended matter in coolant 26 . The timing for cleaning the cooler 6 is determined from the measurement result of the monitor 12 .

In this embodiment, the purifier 8 and sterilizer 10 are located upstream of the inlet I of the cooler 6 and the monitor 12 is located downstream of the outlet O of the cooler 6 . The positions of the purifier 8, the sterilizer 10 and the monitor 12 are not limited to this position. A purifier 8 or sterilizer 10 may be located downstream of the outlet O and a monitor 12 may be located upstream of the inlet I.

A method of manufacturing the sheet 16 using this apparatus 2 includes a rolling process and a cooling process.

In the rolling process, hot unvulcanized rubber 14 is supplied to the rolling mill 4 . Calender rolls 18 rotate and unvulcanized rubber 14 is passed between these calender rolls 18 . The unvulcanized rubber 14 is rolled into a band shape. Thus, a strip-shaped uncooled sheet 20 is obtained. The thickness of the uncooled sheet 20 is typically 0.5 mm to 2.0 mm. Uncooled sheet 20 is sent to cooler 6 .

In the cooling process, a cooling liquid 26 is sent to the manufacturing apparatus 2 from a pump (not shown). The direction in which coolant 26 from the pump flows is indicated by arrow A in FIG. Cooling liquid 26 passes through purifier 8 and sterilizer 10 and is sent from inlet I to cooler 6 . The cooling liquid 26 flows into the rearmost cooling drum 22 . The cooling liquid 26 passes through the flow path formed by the cooling drum 22 and the connecting pipe 24 and is discharged from the outlet O. As shown in FIG. This coolant 26 passes through the monitor 12 and is returned to the pump. A cooling liquid 26 is circulated by the pump. In this embodiment, the flow rate of the circulated coolant 26 is between 200 L/min and 600 L/min.

In the cooling process, the cooling liquid 26 is circulated, and each cooling drum 22 rotates in the direction of the arrow in FIG. An uncooled sheet 20 sent from the rolling mill 4 is moved on a cooling drum 22 . Uncooled sheet 20 moves in the direction of arrow B in FIG. The uncooled sheet 20 is sent in order from the front cooling drum 22 to the rear cooling drum 22 . As described above, the rear cooling drum 22 is upstream of the flow path of the cooling liquid 26 . The uncooled sheet 20 is sequentially moved over these cooling drums 22 from the cooling drum 22 located downstream of the flow path toward the cooling drum 22 located upstream. The uncooled sheet 20 is cooled by moving on the cooling drum 22 . A sheet 16 is thus obtained.

The effects of the present invention will be described below.

In this device 2 , a plurality of cooling drums 22 of the cooler 6 are connected by connecting pipes 24 , and these cooling drums 22 and connecting pipes 24 form one flow path for cooling liquid 26 . In this device 2, the cooling liquid 26 always flows stably at the same flow rate to all the cooling drums 22. FIG. This contributes to reducing temperature variations in the sheet 16 . With this apparatus 2, a sheet 16 with reduced temperature variation is obtained. With this apparatus 2, a sheet 16 with reduced variation in adhesive strength is obtained.

In this apparatus 2, the uncooled sheet 20 is sequentially moved on these cooling drums 22 from the cooling drum 22 located downstream of the flow path toward the cooling drum 22 located upstream. In this device 2 , the temperature of the cooling liquid 26 in the cooling drum 22 can become higher as the heat of the uncooled sheet 20 is removed toward the downstream side of the flow path. The cooling liquid 26 in the cooling drum 22 positioned furthest upstream in the flow path is hardly affected by the heat of the uncooled sheet 20 . The uncooled sheet 20 is finally cooled on this cooling drum 22 . This makes it possible to obtain a sheet 16 of a given temperature. With this device 2, a sheet 16 with good adhesion is obtained.

In this device 2, as described above, the cooling drum 22 and the connecting pipe 24 form a single flow path for the cooling liquid 26, and the uncooled sheet 20 is transferred upstream from the cooling drum 22 located downstream of the flow path. It is possible to obtain the sheet 16 having good adhesive strength and suppressed variations in adhesive strength by sequentially moving the sheet 16 toward the cooling drum 22 positioned at . This device 2 does not have a complicated control mechanism for increasing the accuracy of temperature control of the sheet 16 . The mechanism of this device 2 is simple. This contributes to cost reduction.

The flow rate of the coolant 26 is preferably 200 L/min or more as described above. In this device 2, a single flow path for the cooling liquid 26 is formed, so even if the flow rate is increased to 200 L/min or more, all the cooling drums 22 are stably supplied with the same flow rate of the cooling liquid 26. flow. The uncooled sheet 20 is effectively cooled by flowing the cooling liquid 26 at 200 L/min or more through one channel. This effectively contributes to good adhesive strength of the sheet 16 and reduction of variations in adhesive strength. From this point of view, the flow rate of the coolant 26 is more preferably 300 L/min or more. The flow rate of the coolant 26 is preferably 600 L/min or less. By setting the flow rate of the cooling liquid 26 to 600 L/min or less, the scale of the device 2 can be appropriately suppressed. This prevents the cost of the device 2 from increasing.

This device 2 comprises a clarifier 8 . This purifier 8 removes suspended matter in the coolant 26 . This prevents clogging of the cooling drum 22 and connecting tube 24 . This contributes to a stable flow of coolant 26 . In this device 2, the uncooled sheet 20 is stably cooled. With this apparatus 2, a sheet 16 with little temperature variation can be obtained. This effectively contributes to reducing variations in adhesive strength of the sheet 16 .

This device 2 comprises a sterilizer 10 . By sterilizing the coolant 26 with this sterilizer 10, generation of biofilm in the coolant 26 is prevented. This prevents clogging of the cooling drum 22 and connecting tube 24 . This contributes to a stable flow of coolant 26 . In this device 2, the uncooled sheet 20 is stably cooled. With this apparatus 2, a sheet 16 with little temperature variation can be obtained. This effectively contributes to reducing variations in adhesive strength of the sheet 16 .

This device 2 comprises a monitor 12 for monitoring the liquid quality of the coolant 26 . From the results of the monitor 12, the time for cleaning the cooler 6 is determined. In this device 2, the coolant 26 can be replaced and the cooler 6 can be cleaned at appropriate times. With this apparatus 2, a sheet 16 with little temperature variation can be obtained. This effectively contributes to reducing variations in adhesive strength of the sheet 16 .

The moving speed of the uncooled sheet 20 is preferably 60 m/min or less. By setting the moving speed of the uncooled sheet 20 to 60 m/min or less, the uncooled sheet 20 can be sufficiently cooled by the cooler 6 . This makes it possible to obtain the sheet 16 at the desired temperature. With this device 2, a sheet 16 with good adhesion is obtained. From this point of view, the moving speed is more preferably 55 m/min or less. The moving speed of the uncooled sheet 20 is preferably 30 m/min or more. By setting the moving speed to 30 m/min or more, the uncooled sheet 20 can be efficiently cooled. This contributes to improved productivity. From this point of view, the moving speed is more preferably 40 m/min or more.

The number of cooling drums 22 is preferably eight or more. By setting the number of cooling drums 22 to eight or more, the uncooled sheet 20 can be sufficiently cooled by the cooler 6 . This makes it possible to obtain the sheet 16 at the desired temperature. With this device 2, a sheet 16 with good adhesion is obtained. The number of cooling drums 22 is preferably 12 or less. By setting the number of cooling drums 22 to 12 or less, the scale of the apparatus 2 can be appropriately suppressed. This prevents the cost of the device 2 from increasing.

The temperature of the coolant 26 sent to the cooler 6 is preferably 30° C. or less. By setting the temperature of the cooling liquid 26 to 30° C. or less, the uncooled sheet 20 can be sufficiently cooled by the cooler 6 . This makes it possible to obtain the sheet 16 at the desired temperature. With this device 2, a sheet 16 with good adhesion is obtained. The temperature of the cooling liquid 26 is preferably 20° C. or higher. By setting the temperature of the cooling liquid 26 to 20° C. or higher, it is possible to suppress the manufacturing cost while achieving sufficient adhesion of the sheet 16 .

In the embodiment described above, one type of unvulcanized rubber 14 is rolled by the rolling mill 4 to obtain the uncooled sheet 20 . A rolling mill may roll two types of unvulcanized rubber, respectively, and bond them together to form an uncooled sheet. In this case, the rolling mill further includes, in addition to the calender rolls 18, a bonding device for bonding sheet-like unvulcanized rubber. An uncooled sheet for an innerliner, for example consisting of two layers of rubber, is thereby obtained. A rolling mill may roll unvulcanized rubber and laminate it to a sheet of cords from both sides to form an uncooled sheet. In this case, the rolling mill further includes a laminator for laminating a sheet of unvulcanized rubber and a sheet of cord. Uncooled sheets, for example for carcasses, are thereby obtained.

The effects of the present invention will be clarified by examples below, but the present invention should not be construed in a limited manner based on the description of these examples.

[Example 1]
Sheets were produced using the apparatus shown in FIGS. The parameters for this fabrication are shown in Table 1. In this manufacturing apparatus, the uncooled sheet is sequentially moved on these cooling drums from the cooling drum located downstream of the cooling liquid flow path toward the cooling drum located upstream. This is indicated in Table 1 in the column "Uncooled Sheet Travel Direction" as "bottom to top". The number of cooling drums is ten. The moving speed of the uncooled sheet was 50 m/min. The thickness of the obtained sheet was 1.6 mm. The target temperature of the sheet is 25°C.

[Comparative Example 1]
In the apparatus of Comparative Example 1, the uncooled sheet is sequentially moved on these cooling drums from the cooling drum positioned upstream in the flow path of the cooling liquid toward the cooling drum positioned downstream. This is indicated in Table 1 in the column "Uncooled Sheet Travel Direction" as "top to bottom". The flow rate of the cooling liquid was as shown in Table 1. A sheet was produced in the same manner as in Example 1 except for these.

[Example 2-4]
Example 2-4 is the same as Example 1 except that the flow rate of the cooling liquid is as shown in Table 1.

[Seat temperature]
The surface temperature of the sheet immediately after being manufactured was measured. Ten measurement positions were randomly selected within a range of 10 m in length of the sheet. These average temperatures are shown in Table 1 as "seat temperature". It is preferable that this is closer to the target temperature of 25°C.

[Adhesive strength and standard deviation of adhesive strength]
After the obtained sheet was left for 2 hours, the adhesive strength of the sheet was measured. A PICMA tack tester manufactured by Toyo Seiki Co., Ltd. was used for the measurement. Ten measurement positions were randomly selected within a range of 10 m in length of the sheet. The average value of the measured adhesive strength is shown in the "adhesive strength" column of Table 1, and the standard deviation thereof is shown in the "adhesive strength standard deviation" column. The greater the "adhesive strength", the greater the adhesive strength. The smaller the "adhesion standard deviation", the smaller the variation in adhesion. This is preferably as small as possible.

As shown in Table 1, the production apparatus of the example is comprehensively superior to the production apparatus of the comparative example. From this evaluation result, the superiority of the present invention is clear.

The apparatus described above can also be applied to the production of different sheets for different tires.

DESCRIPTION OF SYMBOLS 2... Manufacturing apparatus 4... Roller 6... Cooler 8... Purifier 10... Sterilizer 12... Monitor device 14... Unvulcanized rubber 16... Sheet 18 ... Calendar roll 20 ... Uncooled sheet 22 ... Cooling drum 24 ... Connection pipe 26 ... Cooling liquid

Claims (6)

A sheet manufacturing apparatus used in a tire molding process,
Equipped with a rolling mill for forming a band-shaped uncooled sheet from hot unvulcanized rubber, and a cooler for obtaining a sheet by cooling the uncooled sheet,
The cooler comprises a plurality of cooling drums in which cooling liquid flows, and a connecting pipe connecting between these cooling drums,
A cooling liquid flow path is formed by the cooling drum and the connection pipe,
A sheet manufacturing apparatus, wherein the uncooled sheet is sequentially moved on these cooling drums from a cooling drum located downstream of the flow path toward a cooling drum located upstream of the flow path. 2. The manufacturing apparatus according to claim 1, wherein the flow rate of the cooling liquid flowing through said flow path is 200 L/min or more and 600 L/min or less. 3. The manufacturing apparatus according to claim 1, further comprising a purifier for removing foreign matter in said coolant. 4. The manufacturing apparatus according to any one of claims 1 to 3, further comprising a sterilizer that sterilizes the coolant. 5. The manufacturing apparatus according to any one of claims 1 to 4, further comprising a monitor for monitoring the liquid quality of said coolant. A method for manufacturing a sheet used in a tire molding process,
A process of forming an uncooled sheet from high-temperature unvulcanized rubber, and a cooler in which a single cooling liquid flow path is formed by a plurality of cooling drums in which cooling liquid flows and connecting pipes connecting these drums. , the step of cooling the uncooled sheet by sequentially moving it over these cooling drums from a cooling drum located downstream of the flow path toward a cooling drum located upstream of the flow path. Method.

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