JP4743785B2 - Rubber sheet manufacturing method - Google Patents

Description

  The present invention relates to a method for producing a rubber-like sheet in which a rolled high-temperature rubber-like sheet is quickly and stably cooled by a temperature-controlled cooling drum to stabilize the stickiness of the rubber-like sheet.

  Generally, tire components such as an inner liner, a carcass ply, and a breaker ply used in tire manufacture are rubber sheets made of unvulcanized rubber, or rubber with a cord in which a tire cord is embedded in unvulcanized rubber. It is formed based on a rubber-like sheet that is a sheet.

  The rubber-like sheet is formed by rolling high-temperature unvulcanized rubber with a rolling device such as a calendar, but the high-temperature rubber-like sheet immediately after rolling has internal strain. Therefore, dimensional changes are likely to occur, such as shrinkage. Therefore, the high-temperature rubber-like sheet formed by rolling is cooled by being passed between the cooling drums of a cooling device having a plurality of cooling drums, and then wound and stored in a roller shape via a release sheet. , And transport and supply to the next process. As described above, since the conventional cooling process is performed in consideration of the dimensional change after the rolling of the rubbery sheet, the temperature control for the cooling device is limited to the temperature setting according to the season and the temperature in the factory. It was.

  On the other hand, in order to improve the productivity and quality of tires, there is a strong demand for improvement in adhesiveness and stabilization of adhesiveness in the rubbery sheet. As a result of studies conducted by the present inventors in view of such a situation, it has been found that the variation in adhesiveness in the rubber-like sheet greatly affects the cooling after rolling. Specifically, when the cooling by the cooling device is insufficient, heat is released after the rubber-like sheet is wound, and during that time, sulfur, stearic acid, etc. blended in the rubber as an additive are adhesion-inhibiting substances. As a result, it was found that it was deposited on the surface of the sheet to reduce the adhesiveness of the rubbery sheet. In particular, the cooling efficiency is not limited to external temperature fluctuations such as the temperature in the factory, and the cooling drum itself is affected by the temperature of the rubbery sheet. It will change with it, and the adhesiveness of a rubber-like sheet will fall and it will be made to vary.

  Therefore, the present invention can stably cool the rolled high-temperature rubber-like sheet to a desired cooling temperature, suppress the precipitation amount and variation of the adhesion-inhibiting substance, and increase the stickiness of the rubber-like sheet. And it aims at providing the manufacturing method of the rubber-like sheet which can be stabilized.

Japanese Patent Laid-Open No. 11-34096 JP 2004-330450 A

In order to achieve the above object, the invention of claim 1 of the present application includes a rolling step in which a high-temperature unvulcanized rubber is rolled with a rolling device to form a rubbery sheet, and the rolled rubber sheet is divided into a plurality of rubber sheets. A cooling step of cooling between the cooling drums of a cooling device having a cooling drum, and a cooling temperature control for controlling the drum temperature of the cooling drum,
The cooling temperature control is a temperature measurement process for measuring the surface temperature of the rubbery sheet cooled in the cooling step for each time pitch to obtain a temperature measurement value,
A temperature storage process for storing a reference temperature range of the surface temperature set in advance;
And a cooling drum temperature control process for controlling the drum temperature of the cooling drum based on the reference temperature range stored in the temperature storage process and the measured temperature value measured in the temperature measurement process ,
The cooling drum temperature control process obtains an approximate curve based on a plurality of temperature measurement values for each time pitch,
Predict the next temperature measurement from this approximate curve,
And comparing this expected next temperature measurement with the reference temperature range,
When the predicted next temperature measurement value exceeds the reference temperature range, prior control for changing the drum temperature is performed before the next temperature measurement is performed .

In the invention of claim 2, the cooling drum temperature control process is characterized in that an approximate curve is obtained based on a plurality of temperature measurement values for each time pitch and using three or more temperature measurement values . .

As described above, the present invention measures the surface temperature of the cooled rubbery sheet every predetermined time pitch, and based on the temperature measurement value obtained thereby and the reference temperature range of the preset surface temperature, the prior control is changing the drum temperature of the cooling drum.

In the preceding control, a temperature measurement value by the next temperature measurement is predicted based on a plurality of temperature measurement values for each time pitch, and the predicted next temperature measurement value is compared with the reference temperature range. To do. Then, when the predicted next temperature measurement value exceeds the reference temperature range, the drum temperature is changed before the next temperature measurement is performed. In the follow-up control, the temperature measurement value for each time pitch is compared with the reference temperature range. When the temperature measurement value for each time pitch exceeds the reference temperature range, the drum temperature is changed before the next temperature measurement.

  Thus, in both the preceding control and the follow-up control, the surface temperature of the cooled rubber-like sheet itself is measured at every predetermined time pitch, and the temperature measurement value is fed back so that the drum is measured before the next temperature measurement. The temperature is adjusted. Therefore, the temperature of the rubber-like sheet after cooling can be stabilized without being affected by the temperature in the factory, the temperature of the rubber sheet immediately after rolling, or the like. As a result, the amount of adhesion-inhibiting substances deposited and fluctuations thereof can be kept low, the adhesiveness of the rubbery sheet can be increased and stabilized, and the productivity after the next process including tire productivity is achieved. And processability can be improved. In particular, since the drum temperature is adjusted by feeding back the temperature measurement value until the next temperature measurement, fluctuations in the cooling temperature can be reduced, and more accurate temperature control can be performed.

  In the preceding control, the drum temperature is adjusted before the temperature measurement value exceeds the reference temperature range, so that quicker and more accurate temperature control is possible. In the follow-up control, the temperature control can be quickly and accurately performed by setting the reference temperature range narrow.

  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 rubbery sheets for carrying out the method for producing rubbery sheets of the present invention.

  As shown in FIG. 1, a rubber-like sheet production line 1 (hereinafter referred to as production line 1) is, in this example, a production line for a rubber-like sheet W for forming an inner liner of a tire, which is not heated at high temperature. A rolling step S1 in which the rubber rubber G is rolled by the rolling device 2 to form a rubber-like sheet W, and the rolled rubber sheet W is interposed between the cooling drums 3 and 3 of the cooling device 4 having a plurality of cooling drums 3. And a cooling step S2 for cooling through and a cooling temperature control S3 for controlling the drum temperature TR of the cooling drum 3.

  In this example, the rolling device 2 is a calendar device 7 having a known structure using a pair of calendar rolls 7A and 7A, and the unvulcanized rubber G is placed between the calendar rolls 7A and 7A with a desired thickness ( For example, in the case of an inner liner, it is rolled to a thickness of about 2.0 mm). The calender rolls 7A and 7A are driven to rotate at the same speed, and the gap between the calender rolls 7A and 7A is configured to be adjustable according to the thickness of the rubber-like sheet W to be rolled. Further, the unvulcanized rubber G is sequentially fed into the rolling device 2 from, for example, a carry-in conveyor or the like in a high temperature state that has been preheated, kneaded and plasticized.

  Next, the cooling device 4 includes a plurality of cooling drums 3 that are rotatably supported, and the rubber sheet W is cooled by contacting the outer peripheral surface of each cooling drum 3. In this example, the cooling drums 3 are arranged in, for example, two rows on the left and right sides (or two rows on the upper and lower sides), and the rubber-like sheets W are alternately arranged between the cooling drums 3 on one row and the cooling drums 3 on the other row. Wrapped while folding. Thereby, the rubber-like sheet W is uniformly cooled from both sides such that the front surface and the back surface of the rubber-like sheet W are alternately brought into contact with the one row of cooling drums 3 and the other row of cooling drums 3. Note that the number of cooling drums 3 in each of the following columns is the same.

  The cooling drum 3 has a well-known structure in which a coolant flow path through which a coolant such as water passes, for example, and controls the drum temperature TR of the cooling drum 3 by adjusting the temperature of the coolant. it can. The “drum temperature TR” is a temperature inside the drum and substantially matches the temperature of the coolant.

  In the production line 1 of the present embodiment, the amount of the adhesion-inhibiting substance in the rubber is precipitated by controlling the drum temperature TR of the cooling drum 3 and accurately cooling the rubber sheet W to the desired cooling temperature T2. And cooling temperature control S3 which suppresses the fluctuation | variation low is performed.

As shown in the flowchart of FIG. 2, the cooling temperature control S3 is as follows: (1) The surface temperature of the rubber-like sheet W cooled in the cooling step S2 is measured for each predetermined time pitch, and the temperature for each time pitch is measured. Temperature measurement processing for obtaining a measurement value t,
(2) a temperature storage process for storing a reference temperature range TK of the surface temperature ts set in advance; and (3) the reference temperature range TK stored in the temperature storage process and the temperature measurement process. A cooling drum temperature control process for controlling the drum temperature TR of the cooling drum 3 based on the measured temperature value t.
It is performed including.

  In the temperature measurement process, the temperature measurement is performed at an outlet vicinity position P of the cooling step S2. The outlet vicinity position P is a region range that is separated from the most downstream cooling roller 3E located on the most downstream side among the plurality of cooling drums 3 by a distance of 20 cm or more and 200 cm or less. If it is too close to the outlet vicinity position P, the difference between the surface temperature and the internal temperature is large, and if it is too far away, the measurement is inaccurate, for example, it is affected by the factory temperature.

  Further, since the rubber-like sheet W is uniformly cooled from both sides as described above, the temperature measurement can be performed only on one surface of the rubber-like sheet W. In addition, when performing on both surfaces, the average value can be employ | adopted as the temperature measurement value t, for example, or the high temperature side can be employ | adopted. For this temperature measurement, it is preferable to use a non-contact type thermometer 10 such as a radiation thermometer or an optical thermometer. Further, the time pitch is not particularly limited, but if it is too long, the temperature fluctuation becomes large, and if it is too short, the quality becomes excessive and the cooling temperature control S3 becomes complicated. From such a viewpoint, the lower limit of the time pitch for temperature measurement is preferably 5 seconds or more, more preferably 10 seconds or more, and the upper limit is preferably 60 seconds or less, more preferably 30 seconds or less. Note that the temperature measurement value t for each time pitch is stored in the first storage unit 11A of the control device 11 which can be temporarily stored, for example, as conceptually shown in FIG.

  In the temperature storage process, a preset reference temperature range TK of the surface temperature is stored in a rewritable second storage unit 11B (shown in FIG. 3) in the control device 11, for example. This reference temperature range TK is appropriately set in consideration of the use of the rubbery sheet to be manufactured, the rubber composition, and the like. For example, in the case of a rubber-like sheet for an inner liner, it is preferably about 38 ± 1.0 ° C.

  Next, as the cooling drum temperature control process, based on the measured temperature value t stored in the first storage unit 11A and the reference temperature range TK stored in the second storage unit 11B, a preceding process is performed. Either control or follow-up control is performed.

In the preceding control, as shown in FIG.
(A) Prediction step of predicting the temperature measurement value tx by the next temperature measurement based on the temperature measurement value t multiple times for each time pitch:
(B) Comparison step for comparing the predicted next temperature measurement value tx with the reference temperature range TK:
(C) When the predicted next temperature measurement value tx exceeds the reference temperature range TK, a control step of changing the drum temperature before performing the next temperature measurement:
With Each step is performed by, for example, an arithmetic processing unit 11C (shown in FIG. 3) in the control device 11.

  Specifically, as shown in FIGS. 5A and 5B, the prediction step includes the current temperature measurement value t0 and the past i temperature measurement values t-1, t-2,... T. A total of i + 1 temperature measurement values t including -i are analyzed to predict the next temperature measurement value tx. In the figure, an approximate curve (function) f is obtained from a total of three (i = 2) temperature measurement values t0, t-1, t-2, and the next temperature measurement value tx is obtained from this approximate curve (function) f. The case where it anticipates is illustrated. In order to increase the prediction accuracy, it is preferable to use at least three temperature measurement values t.

  In the control step, when the next temperature measurement value tx predicted in the comparison step exceeds the reference temperature range TK, the drum temperature is changed before the next temperature measurement. Note that “exceeding the reference temperature range TK” means that the expected temperature measurement value tx exceeds the reference temperature range TK downward (tx <TK), that is, when it is lower and exceeds the upper side (tx> TK). That is, it includes the case where it exceeds. For example, when it exceeds, the drum temperature TR is changed to a new set temperature TRx that is lower than the current set temperature TR0 by a correction temperature ΔT.

  Here, the correction temperature ΔT of the drum 3 is set in advance, and preferably, an excess width δ (that is, a temperature difference | tx−TK) when the expected temperature measurement value tx exceeds the reference temperature range TK. |) Is preferably controlled so that the correction temperature ΔT can be changed in multiple stages (ΔT1, ΔT2,...). For example, the correction temperature ΔT is set in two stages (ΔT1 (1.0 ° C.) and ΔT2 (2. ° C.), and when the excess width δ is small, for example, less than 0.5 ° C., the correction temperature ΔT is ΔT1 (1.0 ° C.) is adopted, and when the excess width δ is large, for example, 0.5 ° C. or more, ΔT2 (2.0 ° C.) is adopted as the correction temperature ΔT. The number of steps of the correction temperature ΔT and the temperature difference between the steps are set in consideration of the rubber composition, the thickness, etc. of the rubber sheet W. The correction temperature ΔT is set to one step (ΔT1). ), And can be changed by ΔT1 (for example, 1.0 ° C.) uniformly regardless of the excess width δ.

Next, the case of follow-up control will be described. In this follow-up control, there is no prediction step as in the preceding control, and as shown in FIG.
(D) A comparison step for directly comparing the temperature measurement value t for each time pitch with the reference temperature range TK:
(E) When the temperature measurement value t exceeds the reference temperature range TK, a control step of changing the drum temperature before performing the next temperature measurement:
With These steps are also performed by, for example, the arithmetic processing unit 11B (shown in FIG. 3) in the control device 11.

  The control step is substantially the same as in the case of the preceding control. For example, when the control step is exceeded, the drum temperature TR is changed to a new set temperature TRx that is lower than the current set temperature TR0 by the correction temperature ΔT. The correction temperature ΔT can also be set in multiple stages, and the correction temperature ΔT can be changed according to the excess width δ, or can be set only in one stage and controlled at one correction temperature ΔT regardless of the excess width δ. You can also

This follow-up control is delayed in response compared to the preceding control. Therefore, it is preferable to set the reference temperature range TK narrower than in the case of the preceding control. For example, when the reference temperature range TK for the preceding control is 38 ± 1.0 ° C. , the reference temperature range TK for the follow-up control is set to 38 ± 0.75 ° C.

  In the production line 1 of the present embodiment, the rubber-like sheet W cooled in the cooling step S2 is conveyed to the winding device via an accumulator that temporarily stores the rubber-like sheet W, as in the conventional case, and the roller It is wound up into a shape, stored, transported to the next process, and supplied.

  As described above, the cooling temperature control measures the surface temperature of the cooled rubber-like sheet W itself every predetermined time pitch and feeds back the temperature measurement value t to the drum before the next temperature measurement. The temperature TR is adjusted. Therefore, the temperature of the rubber-like sheet W after cooling can be stabilized without being affected by the temperature in the factory, the temperature of the rubber sheet W itself immediately after rolling, or the like. As a result, the amount of adhesion-inhibiting substances deposited and their fluctuations can be kept low, and the adhesiveness of rubber-like sheets can be increased and stabilized. And processability can be improved.

  The rubber-like sheet W may be a rubber sheet containing a cord in which a tire cord is embedded in unvulcanized rubber, such as for carcass ply and breaker ply. For example, a topping process using a calendar-type topping device is performed. In this topping process, two rubber-like sheets are rolled and bonded together on the front and back of the cord array body, so it is considered that the process includes a rolling process. As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

Using the manufacturing method according to the present invention, a rubber sheet for an inner liner having a thickness of 2.0 mm was manufactured with the following specifications.
(1) In the conventional example, the drum temperature TR is constantly managed at 12 ° C. as the cooling temperature control.
(2) In Example, a cooling temperature control employs a preceding control. In this advance control, the temperature measurement time pitch is set to 30 seconds / time, the reference temperature range TK is set to 38 ± 1.0 ° C. , the correction temperature ΔT is set to two steps of 1 ° C. and 2 ° C. When the temperature is less than 5 ° C., the correction temperature ΔT (1 ° C.) is set, and when the temperature is 0.5 ° C. or more, the temperature ΔT (2 ° C.) is set.
(3) In the comparative example , follow-up control is adopted as the cooling temperature control. In this follow-up control, the temperature measurement time pitch is set to 30 seconds / time, the reference temperature range TK is set to 38 ± 1.0 ° C. , the correction temperature ΔT is set to two steps of 1 ° C. and 2 ° C. When the temperature is less than 5 ° C., the correction temperature ΔT (1 ° C.), and when the temperature is 0.5 ° C. or more, the temperature ΔT (2 ° C.) is set.

  And the surface temperature of the rubber sheet immediately after passing through a cooling process is measured every 2 hours from the start of production, the temperature change is compared, and the result is shown in Table 1. Further, after the start of production, the rubbery sheet produced after 2 hours passed, after 10 hours passed, after 20 hours passed, after 30 hours passed, after 40 hours passed was sampled, and its adhesiveness was measured and compared. The adhesiveness was measured at three positions in the width direction of the rubber sheet using a PICMA tack tester manufactured by Toyo Seiki Co., Ltd., and the values were averaged.

As shown in Table 1, in the conventional example, the average value of the surface temperature is 40.6 ° C., the standard deviation σ is 2.57, and the adhesive variation width is 2.0 N / cm ^2. 1, the average value of the surface temperature is 37.88 ° C., the standard deviation σ is 1.04, the adhesive variation width is 1.5 N / cm ² , and in Example 2, the average value of the surface temperature is 38.2 ° C. The standard deviation σ is 1.58, and the adhesive variation width is 1.9 N / cm ^2.
It can be confirmed that it has been improved.

It is a side view which shows notionally a part of production line of the rubber-like sheet for enforcing the manufacturing method of the rubber-like sheet of the present invention. It is a flowchart explaining cooling temperature control. It is a conceptual diagram explaining a control apparatus. It is a flowchart explaining preceding control. (A), (B) is a graph of the time-temperature measured value which shows an example of an anticipation step. It is a flowchart explaining follow-up control.

Explanation of symbols

2 Rolling device 3 Cooling drum 4 Cooling device G Unvulcanized rubber S1 Rolling step S2 Cooling step t, tx Temperature measurement value TK Reference temperature range TR Drum temperature W Rubber-like sheet

Claims (2)

A rolling process in which high-temperature unvulcanized rubber is rolled with a rolling device to form a rubber-like sheet, and the rolled rubber sheet is cooled between the cooling drums of a cooling device having a plurality of cooling drums. A cooling step and a cooling temperature control for controlling the drum temperature of the cooling drum,
The cooling temperature control is a temperature measurement process for measuring the surface temperature of the rubbery sheet cooled in the cooling step for each time pitch to obtain a temperature measurement value,
A temperature storage process for storing a reference temperature range of the surface temperature set in advance;
And a cooling drum temperature control process for controlling the drum temperature of the cooling drum based on the reference temperature range stored in the temperature storage process and the measured temperature value measured in the temperature measurement process ,
The cooling drum temperature control process obtains an approximate curve based on a plurality of temperature measurement values for each time pitch,
Predict the next temperature measurement from this approximate curve,
And comparing this expected next temperature measurement with the reference temperature range,
A method for producing a rubber-like sheet , wherein when an expected next temperature measurement value exceeds the reference temperature range, prior control is performed to change the drum temperature before performing the next temperature measurement . The rubber-like sheet according to claim 1, wherein the cooling drum temperature control processing obtains an approximate curve based on a plurality of temperature measurement values for each time pitch and using three or more temperature measurement values. Manufacturing method.

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