JP2016010895A - Method and apparatus for production of composite rubber sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a composite rubber sheet which can suppress effectively temporal deformation, like surface waviness of the composite rubber sheet.SOLUTION: A production method is for production of a composite rubber sheet 15 composed of a first rubber sheet 11 an a second rubber sheet 12, stuck together. The production method of the composite rubber sheet includes a sheet formation step 2 of forming the first rubber sheet 11 and the second rubber sheet 12 by using a calender roll 23 and an assemble step 4 of sticking the first rubber sheet 11 and the second rubber sheet 12 together to obtain the composite rubber sheet 15, and the assemble step 4 is carried out in such a manner as to equalize the remaining shrink amount of the first rubber sheet 11 to the remaining shrink amount of the second rubber sheet 11.

Description

  The present invention relates to a method and apparatus for manufacturing a composite rubber sheet that can suppress deformation over time such as undulation.

  For example, Patent Document 1 below discloses a method for manufacturing a composite rubber sheet in which two rubber sheets are bonded together. The manufacturing method of Patent Document 1 includes a sheet molding process in which two rubber sheets having different compositions are bonded together to form a composite rubber sheet, a cooling process for cooling the composite rubber sheet, and a cooled composite rubber sheet. And a winding process for winding.

  In patent document 1, the movement speed of the composite rubber sheet in the sheet molding process and the movement speed of the composite rubber sheet in the cooling process are adjusted to cause slack in the composite rubber sheet in the cooling process. . This promotes shrinkage of the composite rubber sheet during the cooling process.

  However, rubbers with different blends have different shrink rates. For this reason, for example, during the cooling process, there has been a problem that the composite rubber sheet itself is likely to be deformed with time such as bending and undulation accompanying the difference in shrinkage rate.

JP 2010-173223 A

  The present invention has been devised in view of the actual situation as described above, and the assembly process is performed with the remaining shrinkage amount of each rubber sheet being substantially equal, so that the composite rubber sheet can be deformed over time such as undulation. The main object is to provide a method for producing a composite rubber sheet that can be effectively suppressed.

  The present invention includes a first rubber sheet made of an unvulcanized first rubber material and shrinking over time, and a second rubber sheet made of an unvulcanized second rubber material and shrinking over time. A method for producing a bonded composite rubber sheet, comprising: a sheet forming step of forming the first rubber sheet and the second rubber sheet using a calendar roll; and the first rubber sheet and the second rubber sheet. An assembling step for obtaining the composite rubber sheet by bonding together, and the assembling step is performed by making the remaining shrinkage of the first rubber sheet substantially the same as the remaining shrinkage of the second rubber sheet. It is characterized by that.

  The method for producing a composite rubber sheet of the present invention further includes a heating step of individually heating the first rubber sheet and the second rubber sheet and adjusting a remaining shrinkage amount of each rubber sheet prior to the assembling step. Is desirable.

  In the method for producing a composite rubber sheet of the present invention, prior to the assembling step, the first rubber sheet and the second rubber sheet are individually conveyed, and the remaining time of each rubber sheet is adjusted by adjusting the conveyance time of each rubber sheet. It is desirable to further include a conveying step for adjusting the amount.

  In the method for producing a composite rubber sheet of the present invention, each remaining shrinkage amount of the first rubber sheet and the second rubber sheet is calculated as a total shrinkage amount St after each rubber sheet is finished shrinking. A step, a step of calculating a first shrink amount S1 in which each rubber sheet contracts after the sheet forming step and before the assembly step, and a step of subtracting the first shrink amount S1 from the total shrink amount St. It is desirable that the calculation is included.

  In the method for producing a composite rubber sheet of the present invention, the first rubber material contains air-impermeable butyl rubber, the second rubber material contains natural rubber with good adhesion, and the composite rubber sheet contains air. It is desirable to be a member for an inner liner of a contained tire.

  The method for producing a pneumatic tire according to the present invention is characterized in that a pneumatic tire is produced using the member for an inner liner obtained by the above method.

  The composite rubber sheet manufacturing apparatus of the present invention includes a first rubber sheet made of an unvulcanized first rubber material and shrinking over time, and an unvulcanized second rubber material and shrinking over time. An apparatus for manufacturing a composite rubber sheet having a second rubber sheet bonded thereto, the sheet forming apparatus for forming the first rubber sheet and the second rubber sheet, and the first rubber sheet and the second rubber A heating device that individually heats the sheet to adjust the amount of remaining shrinkage of each rubber sheet, and the first rubber sheet and the second rubber sheet are individually conveyed, and the conveyance time of each rubber sheet is adjusted to adjust each rubber. A conveying device that adjusts the remaining shrinkage of the sheet, and an assembly device that obtains a composite rubber sheet by bonding the first rubber sheet and the second rubber sheet together, And the heating temperature of the serial heating apparatus is characterized by comprising the shrink amount control device for controlling the transport time of the conveying device.

  In the method for producing a composite rubber sheet according to the present invention, the assembly step is performed by making the remaining shrinkage of the first rubber sheet substantially equal to the remaining shrinkage of the second rubber sheet. Thereby, after an assembly process, each rubber sheet shrinks substantially equally. For this reason, deformation with time such as undulation of the composite rubber sheet is effectively suppressed.

  The apparatus for producing a composite rubber sheet of the present invention includes a shrink amount control device that controls the heating temperature of the heating device and the transport time of the transport device. Such a manufacturing apparatus for a composite rubber sheet can effectively control the amount of remaining shrinkage of the rubber sheet, and as a result, deformation over time such as undulation of the composite rubber sheet is effectively suppressed.

It is a side view which shows the manufacturing line of the composite rubber sheet of this embodiment. It is a graph which shows the change of sheet width W of the 1st rubber sheet 11 and the 2nd rubber sheet 12. It is a graph which shows notionally change of width W of a rubber sheet. It is a block diagram of the electric system of the manufacturing apparatus of the composite rubber sheet of this embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a side view conceptually showing a part of a production line for carrying out the method for producing a composite rubber sheet of the present embodiment. The composite rubber sheet 15 is formed by bonding the first rubber sheet 11 and the second rubber sheet 12 together. The first rubber sheet 11 is made of an unvulcanized first rubber material 11m. The second rubber sheet 12 is made of an unvulcanized second rubber material 12m. The first rubber sheet 11 and the second rubber sheet 12 shrink as time passes.

  As shown in FIG. 1, the composite rubber sheet manufacturing method of the present embodiment includes a sheet forming step 2, a remaining shrinkage amount adjusting step 3, an assembling step 4, and a cooling step 5.

  In the sheet forming step 2, the first rubber sheet 11 and the second rubber sheet 12 are formed. The first rubber sheet 11 and the second rubber sheet 12 are each molded by the sheet molding device 21. Each sheet forming apparatus 21 includes, for example, a rubber extruder 22 and a pair of calendar rolls 23 and 23.

  The rubber extruder 22 extrudes the rubber raw materials 11G and 12G charged from the hopper 24 from the die with a screw. The pair of calendar rolls 23, 23 are arranged with a desired gap and are driven to rotate at the same speed.

  The rubber raw materials 11G and 12G charged from the hopper 24 are heated and kneaded in the rubber extruder 22. As a result, the plasticized high-temperature unvulcanized rubber material is extruded from the rubber extruder 22. The unvulcanized rubber material extruded from the rubber extruder 22 is rolled into, for example, a rubber sheet of about 0.5 to 2.0 mm by the calendar roll 23.

  The first rubber sheet 11 and the second rubber sheet 12 formed in the sheet forming step 2 are sent to the assembling step 4 through the remaining shrinkage amount adjusting step 3, for example.

  In the assembly process 4, an assembly device 41 is used. The assembly device 41 includes, for example, a pair of assembly rolls 42 and 42 that rotate relative to each other. The pair of assembly rolls 42 and 42 are arranged with a desired gap 43 and are driven to rotate relative to each other. The first rubber sheet 11 and the second rubber sheet 12 sent to the assembly process 4 are overlapped with each other and pass through the gap 43. Thereby, the 1st rubber sheet 11 and the 2nd rubber sheet 12 are bonded together, and the composite rubber sheet 15 is obtained.

  In the method for manufacturing a composite rubber sheet of the present invention, the above-described assembly process is performed with the remaining shrinkage of the first rubber sheet 11 and the remaining shrinkage of the second rubber sheet 12 being substantially equal.

  FIG. 2 shows a graph showing changes in the width W of the first rubber sheet 11 and the second rubber sheet 12. In FIG. 2, the horizontal axis represents the elapsed time T, and the vertical axis represents the sheet width W. A solid line shown in FIG. 2 indicates a change in the width of the first rubber sheet 11, and a broken line indicates a change in the width of the second rubber sheet 12.

  As shown in FIG. 2, in the present invention, the remaining shrinkage Sr of the first rubber sheet 11 and the second rubber sheet 12 is substantially equal at the time when the rubber sheet is assembled (T = Ta). Thereby, the width | variety of the 1st rubber sheet and the width | variety of a 2nd rubber sheet become substantially equal at the time of completion | finish of shrink of a composite rubber sheet (T = Tf). Accordingly, deformation with time such as bending and undulation of the composite rubber sheet is effectively suppressed.

  As shown in FIG. 1, in the present embodiment, the remaining shrinkage amount adjusting step 3 is performed prior to the assembling step 4. The remaining shrinkage amount adjusting step 3 adjusts each remaining shrinkage amount Sr of the first rubber sheet 11 and the second rubber sheet 12. The remaining shrinkage amount adjusting process 3 includes, for example, a heating process 6 and a conveying process 7.

  The heating process 6 is performed immediately after the sheet forming process 2, for example. In the heating process 6, the rubber sheet molded in the sheet molding process 2 is heated, and the high temperature state at the time of sheet molding is maintained. The first rubber sheet 11 and the second rubber sheet 12 are individually heated. In general, unvulcanized rubber shrinkage is accelerated in proportion to the temperature of the rubber. For this reason, by adjusting the temperature of the first rubber sheet 11 and the second rubber sheet 12, the remaining shrinkage of each rubber sheet is adjusted.

  The heating device 61 that performs the heating process 6 includes, for example, a heater 62 and a temperature sensor 65. The heater 62 includes, for example, a first heater 63 and a second heater 64.

  The 1st heater 63 is roll shape, for example, and is contacting the conveyance conveyor (not shown) which conveys a rubber sheet or a rubber sheet. The first heater 63 is rotated and heated to convey the rubber sheet.

  The second heater 64 heats the rubber sheet in a non-contact manner, for example, by emitting infrared rays.

  For example, the temperature sensor 65 measures the temperature of the rubber sheet in a non-contact manner. The heating temperature H of the rubber sheet is controlled based on the temperature of the rubber sheet measured by the temperature sensor 65.

  The conveyance process 7 is performed on the downstream side of the heating process 6. In the conveying step 7, the first rubber sheet 11 and the second rubber sheet 12 are individually conveyed. The transport device 71 used in the transport process 7 includes a pair of drawer rolls 72 and 72 and a drawer roll sensor 75. The pair of drawer rolls 72 and 72 are driven to rotate at the same speed, for example. The drawer roll sensor 75 measures the rotational speed of the drawer roll 72, for example.

  In the transport process 7, for example, the rubber sheet is fed to the assembly roll 42 in the assembly process 4 after the rubber sheet is molded by the calendar roll 23 in the sheet molding process 2 by controlling the rotation speed of the drawing roll 72. The conveyance time t until it is adjusted is adjusted, and the remaining shrink amount of each rubber sheet is adjusted accordingly.

  FIG. 3 shows a graph conceptually showing a change in the width W of the sheet when the first rubber sheet 11 or the second rubber sheet 12 shrinks. In FIG. 3, the horizontal axis represents the elapsed time T, and the vertical axis represents the sheet width W. As shown in FIG. 3, in the present embodiment, each remaining shrink amount Sr of the first rubber sheet 11 and the second rubber sheet 12 is, for example, after each sheet is finished shrinking after the sheet forming step (T = 0). A step of calculating a total shrinkage amount St until (T = Tf), and a first shrinkage amount S1 in which each rubber sheet contracts after the sheet forming step (T = 0) to before the assembly step (T = Ta). And a step of subtracting the first shrink amount S1 from the total shrink amount St.

The inventors have found through various experiments that the total shrink amount St of the unvulcanized rubber is proportional to the stress relaxation rate MSR of the rubber material. For this reason, the total shrinkage amount St is calculated by the following formula (1).
St (%) = a × MSR + b (1)
(However, a and b are constants determined by the rubber member.)

  The stress relaxation rate MSR is a logarithmic plot of torque and time from 1.6 seconds to 5 seconds after the rotor was stopped after measuring the Mooney viscosity by a method defined in ISO 289-4: 2003, for example. It is obtained as the absolute value of the slope of time.

The inventors have found through various experiments that the first shrink amount S1 is calculated by the following formula (2) from the heating temperature H in the heating step and the conveyance time t in the conveyance step.
S1 = c * {1-exp (-d * t * H)} (2)

  In the present embodiment, the heating step is performed based on the above-described formulas (1) and (2) so that the remaining shrink amount of the first rubber sheet 11 and the remaining shrink amount of the second rubber sheet 12 are substantially equal. The heating temperature H and the transport time t in the transport process are determined.

  As shown in FIG. 1, the cooling step 5 is performed on the downstream side of the assembly step 4. In the cooling step 5, for example, a cooling device 51 having a cooling roll 52 and a cooling roll sensor 55 is used. For example, the cooling rolls 52 are arranged in a zigzag pattern in the vertical direction. The cooling roll sensor 55 measures, for example, the rotational speed of the cooling roll 52 and the surface temperature of the cooling roll 52.

  The composite rubber sheet 15 sent to the cooling step 5 is conveyed in a zigzag shape while being cooled on both sides by the cooling roll 52. By such a cooling step 5, the shrinking of the composite rubber sheet 15 can be completed.

  The composite rubber sheet 15 of the present embodiment is employed as an inner liner member for a pneumatic tire, for example. The first rubber material 11m of the first rubber sheet 11 of the present embodiment includes air-impermeable butyl rubber. The second rubber material 12m of the second rubber sheet 12 of the present embodiment includes a highly adhesive natural rubber. The inner liner member obtained by the method for producing a composite rubber sheet of the present invention is less susceptible to deformation over time such as undulation, and the variation in the member dimensions with respect to the design dimension is reduced. Therefore, the manufacturing method of the pneumatic tire using the said inner liner member can reduce the defective rate at the time of production. In addition, the pneumatic tire using the inner liner member has improved uniformity.

  A composite rubber sheet manufacturing apparatus used in the method for manufacturing a composite rubber sheet configured as described above will be described.

  As described above, the composite rubber sheet manufacturing apparatus 1 of the present embodiment includes the sheet forming apparatus 21, the heating apparatus 61, the conveying apparatus 71, the assembling apparatus 41, and the cooling apparatus 51. Each of these devices has a well-known structure.

  FIG. 4 shows a block diagram of the electrical system of the composite rubber sheet manufacturing apparatus of the present embodiment. As shown in FIG. 4, the composite rubber sheet manufacturing apparatus of the present embodiment includes the heating temperature of the heater 62 of the heating device 61, the rotational speed of the drawing roll 72 of the transport device 71, and the cooling roll of the cooling device 51. A shrinkage amount control device 31 for controlling the rotation speed and the cooling temperature of 52 is included.

  The shrink amount control device 31 is connected to, for example, the temperature sensors 65a and 65b of the heating device, the drawer roll sensors 75a and 75b of the transport device, and the cooling roll sensor 55 of the cooling device. The shrink amount control device 31 calculates a necessary first shrink amount in a first shrink calculation step 33 based on the measurement results obtained by the respective sensors and the total shrink amount input from the input device 32. On the basis of the result obtained in the first shrink calculation step 33, the shrink amount control device 31 uses the heating temperature of each heater 62 of the heating device 61, the rotation speed of each drawing roll 72 of the transport device 71, and the cooling device 51. The rotation speed and cooling temperature of the cooling roll 52 are controlled.

  The composite rubber sheet manufacturing apparatus having such a shrink amount control device 31 can effectively control the remaining shrink amount of the rubber sheet, and as a result, deformation over time such as undulation of the composite rubber sheet is effectively suppressed. The

  As mentioned above, although the manufacturing method and manufacturing apparatus of the composite rubber sheet of this invention were demonstrated in detail, this invention is changed in various aspects, without being limited to said specific embodiment.

Based on the specifications in Table 1, the amount of corrugation of the rubber sheet was measured for the composite rubber sheet prototyped by the manufacturing method of the present invention and the composite rubber sheet prototyped by the conventional manufacturing method. In the conventional manufacturing method, the first rubber sheet and the second rubber sheet are respectively molded at the same heating temperature and conveyance speed. The common specifications and test methods for rubber sheets are as follows.
First rubber sheet: butyl rubber, thickness 0.90mm
Second rubber sheet: natural rubber, thickness 0.55mm

<Wave amount of rubber sheet>
After completion of shrinkage, the difference between the width of the composite rubber sheet in an unloaded state and the width in a state where the composite rubber sheet was sandwiched between two flat surfaces and the sheet was not wavy was measured. A result is an index | exponent which sets the comparative example 1 to 100, and shows that the amount of corrugation of a rubber sheet is so small that a numerical value is small.

  As a result of the test, it was confirmed that the composite rubber sheet manufacturing method of the present invention reduced temporal deformation such as corrugation of the composite rubber sheet.

2 Sheet forming process 4 Assembly process 11 First rubber sheet 12 Second rubber sheet 23 Calendar roll

Claims (7)

A composite in which a first rubber sheet made of an unvulcanized first rubber material and shrinking over time and a second rubber sheet made of an unvulcanized second rubber material and shrinking over time are bonded together A method for producing a rubber sheet, comprising:
A sheet forming step of forming the first rubber sheet and the second rubber sheet using a calendar roll;
An assembly step of bonding the first rubber sheet and the second rubber sheet together to obtain the composite rubber sheet,
The method for producing a composite rubber sheet, wherein the assembling step is performed with a remaining shrink amount of the first rubber sheet substantially equal to a remaining shrink amount of the second rubber sheet.   The method for producing a composite rubber sheet according to claim 1, further comprising a heating step of individually heating the first rubber sheet and the second rubber sheet to adjust a remaining shrinkage amount of each rubber sheet prior to the assembling step.   Prior to the assembling step, the method further includes a conveying step of individually conveying the first rubber sheet and the second rubber sheet and adjusting a conveyance time of each rubber sheet to adjust a remaining shrinkage amount of each rubber sheet. 3. A method for producing a composite rubber sheet according to 1 or 2. Each remaining shrinkage amount of the first rubber sheet and the second rubber sheet is a step of calculating a total shrinkage amount St after each sheet is finished shrinking after the sheet forming step;
A step of calculating a first shrinkage amount S1 for each of the rubber sheets to be contracted after the sheet forming step and before the assembly step;
The method for producing a composite rubber sheet according to any one of claims 1 to 3, wherein the method is calculated including a step of subtracting the first shrink amount S1 from the total shrink amount St. The first rubber material includes air-impermeable butyl rubber,
The second rubber material includes a highly adhesive natural rubber,
The method for producing an unvulcanized composite rubber sheet according to any one of claims 1 to 4, wherein the composite rubber sheet is a member for an inner liner of a pneumatic tire.   A pneumatic tire is manufactured using the member for inner liners obtained by the method of Claim 5, The manufacturing method of the pneumatic tire characterized by the above-mentioned. A composite in which a first rubber sheet made of an unvulcanized first rubber material and shrinking over time and a second rubber sheet made of an unvulcanized second rubber material and shrinking over time are bonded together An apparatus for producing a rubber sheet,
A sheet forming apparatus for forming the first rubber sheet and the second rubber sheet;
A heating device for individually heating the first rubber sheet and the second rubber sheet to adjust the amount of remaining shrinkage of each rubber sheet;
A conveying device that individually conveys the first rubber sheet and the second rubber sheet, adjusts the conveying time of each rubber sheet, and adjusts the remaining shrinkage of each rubber sheet;
An assembly device for obtaining a composite rubber sheet by bonding the first rubber sheet and the second rubber sheet to each other;
An apparatus for producing a composite rubber sheet, comprising a shrink amount control device for controlling a heating temperature of the heating device and a conveying time of the conveying device.

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