JPH03215010A - Vulcanizing method of elastomer article - Google Patents

Abstract

PURPOSE:To attain a uniform vulcanizing degree, and further prevent positively under cure troubles or vulcanizing delays by discharging the heating medium filled in the inner space of an elastomer article within a mold, and alternatively replacing with a low temperature heating medium for cooling the temperature of the elastomer article. CONSTITUTION:The piping 115 at an outlet side having an orifice 119 is released for a predetermined time, and a heated mixture fluid of the steam and gas filled in the inner space 120 of a tire 104 within a mold 102 is discharged. And accompanying the discharge, from the piping 106 of an inlet side at the outside of the inner space 120 of the tire 104, a pressurized fluid not being heated flows alternatively into the inner space 120 of the tire and fills up the space 120. Namely, the high temperature mixture fluid in the inner space 120 of the tire is replaced with the low temperature pressurized fluid. Whereby, without producing any temperature differences at each phase of an elastomer article within the mold, the cooling is carried out effectively, and a uniformly vulcanizing degree can be obtained, thereby positively preventing troubles such as vulcanizing delays and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a so-called gas vulcanization process for elastomeric articles, particularly rubber tires for vehicles. (Prior Art) The present applicant disclosed a method for gas vulcanization of elastomer articles such as rubber tires for vehicles in Japanese Patent Laid-Open No. 57-74142 as summarized below. That is, Fig. 6 (A) (B)
As shown in FIG. 6, a tire 2 (however, the tire in FIG. 6 shows a tire that is under vulcanization or a completed vulcanization tire) is installed in the mold 1, and a plug 3 is placed along the inner surface of the tire 2 or a bladder 3 is placed along the inner surface of the tire 2.
A heating medium such as steam or heating gas at a predetermined temperature and pressure is supplied into the internal space 6 without using a
(The side piping is in a closed state, so the steam does not circulate and is at a so-called dead end), and when the tire 2 reaches the reference temperature required for vulcanization or the reference time has elapsed, the heating medium is The supply is stopped, and then a pressurized medium (such as combustion gas or nitrogen gas) with a pressure equal to or higher than that of the heating medium is supplied into the tire from the outlet 5 provided in the central mechanism 4 of the vulcanizer ( At this time as well, the "output" side piping is closed, so the gas does not circulate), and the pressure inside the tire 2 is maintained at the same pressure or increased by this high-pressure gas until the end of the remaining time of the heating process. After vulcanization in this manner, if 6-nylon is used as the tire carcass ply, or if the degree of vulcanization needs to be adjusted even in tires made of materials other than 6-nylon, after the heating step. Cooling water is circulated in the inner space 6 of the tire to cool the tire 2 to a predetermined temperature, and then the mixed fluid of the heating medium and the pressurized medium or the mixed fluid of the heating medium and the cooling water is discharged from the discharge line. Then, the bladder is deflated by vacuum and removed from the inside of the tire 2, the mold 1 is released, and the vulcanized tire 2 is taken out to complete the vulcanization process.

(Problems to be Solved by the Invention) A problem in the cooling process of gas vulcanization is that when the cooling water is circulated within the tire internal space, the mixed fluid (
The gas (gas) remains in the upper part In particular, a large temperature difference (for example, about 50°C) occurs between the lower sidewall part and the lower sidewall part. This results in different degrees of vulcanization, leading to a problem of deterioration of quality. Furthermore, the cooling time required to prevent the strength of the 6-nylon cord from decreasing becomes significantly longer, resulting in significantly lower productivity.

Furthermore, if cooling water is used in gas vulcanization, leakage from the cooling water valve will enter the tire's internal space, causing undercure problems (insufficient vulcanization), and the cooling water will cool the piping and bladder. Therefore, there is a problem in that in the subsequent vulcanization step, the heating medium (steam) within the tire interior space is accelerated to drain, thereby delaying vulcanization.

In addition, in the heating process of the gas vulcanization method mentioned above, the problem is that the drain generated by the steam drain is
Tires during vulcanization may accumulate in the sidewall of the lower mold side, or gas may accumulate in the area extending from the bead of the lower mold to part of the shoulder of the upper mold due to insufficient stirring of steam and gas after pressurized medium is supplied. A temperature difference occurs between a region extending from the upper mold side bead portion to a portion of the upper mold side shoulder and a region extending from the lower mold side bead portion to a portion of the lower mold side shoulder. Therefore, the vulcanization time of the tire needs to be determined in accordance with the portion corresponding to the lower mold where vulcanization is delayed (for example, a bead portion or a shoulder portion on the lower mold side). However, with this method, there is a problem that the upper mold corresponding portion (for example, a bead portion or a shoulder portion on the upper mold side) becomes over-vulcanized compared to the lower mold corresponding portion.

On the other hand, the longer the heating (steam) process is, the higher the temperature will be in both the upper and lower mold corresponding parts, although there is a temperature difference. However, if the time of the steam process is too long, the temperature of the upper mold corresponding portion will rise excessively, and the physical properties of the rubber and cord of the carcass portion on the upper mold side will deteriorate.

Considering the lower mold corresponding part, lengthening the steam process time and raising the temperature further leads to shortening the vulcanization time (improving productivity).

However, in order to avoid excessive temperature rise in the upper mold corresponding part,
In other words, the time of the steam process is generally determined in order to control the temperature of the upper mold corresponding part.

As mentioned above, in order to improve the productivity of the vulcanization process in the tire manufacturing process (shorten the vulcanization time), it is necessary to How quickly can we raise the temperature of the mold-side shoulder part), and furthermore, how can we raise and cool the lower mold-corresponding part to a temperature that prevents excessive rise in the temperature of the upper mold-corresponding part and prevents deterioration of the physical properties of the constituent materials? That is necessary.

The present invention solves the above-mentioned problems and can cool elastomer articles such as tires without causing temperature differences in various parts to obtain a uniform degree of vulcanization. It is an object of the present invention to provide a method for vulcanizing elastomer articles that can reliably prevent the above.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for vulcanizing elastomer articles, particularly rubber tires for vehicles, including a heating medium supply step and a pressurized medium supply step following this step. at least once for a predetermined period of time, part or all of the heating medium or heated mixed fluid filling the interior space of the elastomeric article in the mold is evacuated and replaced by a cold pressurized medium. In the first embodiment, the heated mixed fluid is subjected to low-temperature pressurization during and/or after the pressurizing medium supply step. In the second embodiment, the heating medium is replaced with a low-temperature pressurized medium immediately after the heating medium supplying step and before switching to the heating medium supplying step, and after the replacement, the "output" The configuration is such that the side piping is closed. Further, an orifice is provided in the "output" side piping of the vulcanizer to reduce the flow rate.

(Function) In the first embodiment described above, the present invention provides a method for controlling a part of the heated mixed fluid that fills the internal space of the elastomer article in the mold during or after the pressurized medium supply step. Alternatively, by performing a so-called gas purge on the entire volume for a predetermined period of time, the elastomer article is cooled to a desired temperature because the pressurized fluid is replaced with an unheated, low-temperature fluid.Also, during the gas purge, the discharge flow rate is reduced, so that the inside of the elastomer article is The pressure drop in the space is limited to within an acceptable range and the elastomeric article within the mold is effectively cooled without significant temperature differences or undesirable temperature pressure drops. Not only can a uniform degree of vulcanization be obtained, but also troubles such as delayed vulcanization can be reliably prevented.

Further, in the second embodiment of the present invention, immediately after the heating process ends and before the pressurizing process starts, part or all of the heating medium filling the internal space of the elastomer article in the mold is heated for a predetermined period of time. By so-called gas purge, it is replaced with an unheated, low-temperature pressurized medium, and after being replaced, the "output"
By closing the side piping, during the vulcanization of elastomer articles, the temperature rise in the upper mold corresponding part where vulcanization progresses too much is suppressed, while the temperature rise in the lower mold corresponding part where vulcanization is delayed is accelerated, resulting in uniform upper and lower parts. Vulcanization and vulcanization time are shortened.

(Example) An example of the present invention will be described in detail below using a rubber tire for a vehicle with reference to the drawings.

The gas vulcanization method of the present invention is basically the same as the conventional method described above except for the cooling step, so a description of the same parts will be omitted.

FIG. 1 shows a vulcanizer used to carry out the method of the present invention, and this vulcanizer 100 consists of a null body 101a and an internal piping system 10lb. The vulcanizer main body 101a is an upper mold 10
2a and a lower mold 102b, and a rubber bag-like plastica 103, the mold 102 and the bladder 103 are
During this time, an unvulcanized green tire 104 (however, the tire shown in FIG. 1 shows a state in which vulcanization is in progress or has been completed) is held and heated and pressurized. Note that in other embodiments, no bladder is used.

The outlet 106 and the outlet 105 of the vulcanizer main body 101a are connected to a supply source (not shown) of a vulcanizing medium through an in-machine piping system 10lb. The in-flight piping system 10l b is
Supply the vulcanizing medium to the vulcanizer main body 101a [take out the vulcanizing medium discharged from the inlet J side and the zero body 101a]
It is broadly divided into the "exit" side.

In the figure, 107 is the flexible piping on the "output" side, and 1
0B is the second vulcanizer l with flexible piping on the r input side.
The 10lb in-flight piping system of the OO is equipped with the above-mentioned "
A circulation piping 109 forming a path for forced circulation of the vulcanizing medium may be provided between the inlet side and the outlet J side.This piping has a regulating valve VA on the inlet side and an adjustment valve VA on the outlet side. Equipped with valve VB,
Pump P as forced circulation device 110 and check valve 111,
111 is interposed, and the vulcanizing medium filling the inner space of the tire is forcibly circulated at a timely time during vulcanization to obtain the same effect as forced stirring in the mold and eliminate uneven dryness. can.

In the figure, 112 is a supply pipe for pre-shaping process fluid (gas, steam, etc.) prior to the heating process, 113 is a supply pipe for pressurized medium (low-temperature gas such as nitrogen gas), and 114 is a heating medium (steam, heating gas). The supply pipe constitutes an "in" side piping system together with the flexible piping 108, 115 is a mixed fluid gas discharge pipe, 116 is a vacuum pipe, 117
is a drain discharge pipe, which together with the flexible piping 107 constitutes an "outlet" side piping system. In addition, the gas exhaust pipe 11
5 can be connected to a main recovery pipe as shown in FIG. 1(B) to recover the exhaust gas and reuse it for pre-shaving.

Of the above "output" side piping system, the gas discharge pipe (or gas recovery pipe) 115 is located at position W in front of automatic control valve ■4 or at position X (dotted line circle) past automatic control valve v4. An orifice 119 of known construction is provided to throttle the. The diameter of the orifice 119 is less than 20 mm, particularly preferably from 3.0 m to less than 10 mm. If the orifice diameter is too large, the inner space of the tire will be 120 mm when gas is purged.
The pressure drop is large, causing poor tire appearance such as bareness, volocity on the tire surface, or double molding trouble in the lettering on the tire sidewall.Also, if the orifice diameter is too small, the pressure drop can be avoided, but the pressure drop may be avoided. However, it takes too long to achieve the desired level of tire cooling effect through gas purging, and there is a risk of pipe clogging.

As mentioned above, an orifice 1 of a specified diameter is installed in the "output" side piping system.
The first embodiment is carried out as follows using the vulcanizer 100 equipped with the vulcanizer 19.

That is, in the pressurized medium supply process in which the "output" side piping is closed (dead end) and gas is continued to be supplied, similarly to the heating medium supply process, or after this process, the orifice 11
The "output" side piping 115 with 9 is released for a predetermined period of time, and the mold 10
A part or all of the heated steam and gas mixed fluid filling the internal space 120 of the tire 104 in the tire 104 is discharged, and along with the discharge, the internal space 120 of the tire 104 is discharged.
Pressurized fluid that has not been heated from the outside "person" side piping 106 (has never been released from the gas tank and has never entered the tire internal space 120)
New gas that has never entered the interior or forced circulation piping 10
In the case of a vulcanizer having a vulcanizer 9, the used gas (used gas passing through the pipe 109) instead flows into the tire internal space 120 and fills the tire internal space 120. In other words, the tire internal space 1
Part or all of the high temperature mixed fluid of 20 is replaced or replaced with a low temperature pressurized fluid, that is, gas purge cooling is performed.

The timing of gas barge cooling varies depending on the purpose of cooling. i.e. tires with a 6-nylon cord carcass (6-nylon cord is typically 160
It is known that the tensile strength of the nylon cord decreases when the tension is applied to the cord during vulcanization at temperatures above °C and the tension is removed by reducing the pressure to zero upon completion of vulcanization. If cooling is performed solely for the purpose of preventing a decrease in strength, the tire temperature should be kept below 160°C when the pressure inside the tire is reduced to zero upon completion of vulcanization. It may be carried out during the pressurized medium (gas) supply process as shown in A), or it may be carried out after the pressurized medium (gas) supply process and before the gas exhaust process as shown in Figure 2 (B). In other words, it can also be carried out at the final stage of vulcanization. When gas barge cooling is performed during the pressurized medium supply process, the temperature is lower because the timing is earlier than when gas purge cooling is performed after the pressurized medium supply process, so the overall vulcanization time becomes longer.

Next, there is a temperature difference between the upper sidewall and the lower sidewall of the tire in the mold, which is a problem in the conventional gas vulcanization method (steam drain remains on the lower sidewall). If you want to improve the uniformity of the degree of vulcanization by eliminating the problems caused by If you want to control the degree of vulcanization by increasing the temperature and lowering the temperature during vulcanization to prevent the inner liner or carcass from becoming over-vulcanized, you can lower the temperature of the inner space of the tire and lower the temperature of the upper and lower sidewalls. If you want to vulcanize, use a pressurized medium (gas) as shown in Figure 2 (A).
Gas purge cooling may be performed during the supply process.

Note that the number of gas purge coolings is usually one, but is of course not limited to this. For example, in the case of a 6-nylon carcass tire, the first gas purge cooling (within the gas supply process) will cool both sides of the tire. After eliminating the temperature difference caused by the drainage pool on the wall, the second gas purge cooling (after the end of the gas supply process) lowers the tire temperature to the limit level of 16
The temperature can be lowered to below 0°C.

The cooling effect of the tire inside the mold is determined by the diameter of the orifice installed in the "output" side piping and the gas purge cooling time.
The first point in determining the cooling effect is to what extent the pressure inside the tire can be lowered. This pressure drop tolerance level (e.g. approximately 7 kg/cd
) will cause bareness or volocity, or problems with double molding of sidewall lettering. Next, determine the original pressure of the gas to be purged (e.g. 21 kg/cd) and the orifice diameter (e.g. 5 uun).
) and the gas pipe diameter (for example, 16 mm),
A desired pressure in the tire internal space during gas purge cooling (for example, 19 kg/csi) can be set.

To determine the gas purge time, first decide on the diameter of the orifice that will keep the pressure drop in the tire's internal space within the allowable range, then attach this orifice to the "output" side piping, fully gas vulcanize the tire, and perform gas purge cooling. By repeating experiments to collect tire temperature measurement data, it is possible to experimentally determine how many orifices and how many minutes gas purge should be performed to obtain the desired cooling effect. In addition, it can be easily confirmed from the pressure graph whether the high temperature mixed fluid in the tire interior space of the mold has been reliably replaced with low temperature fluid by gas purge. Next, by the method of the present invention, a third
As shown in the figure, an orifice with a diameter of 5III1 is placed at position W of the gas discharge pipe 115 to explain the case where a passenger car tire of tire size 165SR13 equipped with a 6-nylon carcass bly is gas-cured in a BOM mold (temperature 160'C). After installing the “out” side piping valve ■, ~■
, and open the valve Vz of the "in" side piping to increase the pressure to 1.
After supplying steam at 4 kg/cd and a temperature of 180 °C for a reference time of 4 minutes, close valve 2 to stop the steam supply, and open valve v1 to increase the pressure to t, N and pressure 21.
kg/ci, temperature 40°C (7) After 2 minutes of supplying gas, perform gas purge cooling as shown in Figure 1. That is, by opening only the valve 4 of the gas exhaust pipe 115, the heated mixed fluid (pressure 21 kg/cj
, temperature 180℃) is discharged (opened to atmosphere), and the pressure is 21 kg/cd,
Gas at a temperature of 40° C. flows into the tire internal space 120 and fills it. After one minute has passed (at this time, the pressure in the tire internal space 120 drops to about 19 kg/cd, but the temperature of the inner liner of the tire drops to about 168°C at the upper sidewall ■■, and the temperature of the upper and lower sidewalls ■■ decreases. The temperature difference is reduced to about 3°C, improving the degree of uniform vulcanization thereafter.

) Valve v4 of the gas exhaust pipe 115 is closed, gas continues to be supplied, and after 3.5 minutes (at this time, the pressure in the tire internal space !20 has returned to 21 kg/ci, and the temperature of the tire inner liner has For example, the temperature has dropped to about 165° C. on the upper sidewall (2), then a second gas purge cooling is performed. That is, only the hub V of the gas exhaust pipe 115 is opened again to exhaust the gas in the tire internal space, and the pressure is 21 kg/cJ and the temperature is approximately 4.
Gas at 0° C. flows into the tire internal space 120 and fills it.

After 3.5 minutes have passed (at this time, the pressure in the tire internal space 120 has decreased to approximately 19 kg/c+fi, but the temperature of the tire inner liner has decreased to approximately 148 kg/c+fi at the upper sidewall).
°C, that is, the temperature level at which no strong drop occurs when the pressure in the tire internal space l20 becomes zero, approximately 160 °C.
The temperature difference between the upper and lower sidewalls was reduced to about 2°C, and the degree of uniform vulcanization was further improved. )
, the valve V of the gas exhaust pipe 115 is closed, gas continues to be supplied, and after 3 minutes, the valve V of the gas supply pipe 113 is closed.
1 to stop the gas supply and close the gas exhaust pipe 11.
Open the valve 4 of No. 5 to exhaust the gas in the tire internal space 120 to make the pressure zero, then vacuum to deflate the Pradder 103 and remove it from the tire. Then, the mold 102a is released and heated. The vulcanized tire 2 is taken out and the entire vulcanization process is completed.

In the above invention, the mixed fluid refers to a gas body in which a vulcanizing medium (steam, heating gas, etc.) and a pressurizing medium (nitrogen gas, air, etc.) are mixed, as is clear from the above description.

As described above, in the first embodiment, in the pressure medium supply step of vulcanizing the elastomer article or after this step,
The configuration is such that the flow rate of the ``out'' side piping of the vulcanizer is squeezed and released by an orifice for a predetermined period of time to perform so-called gas purge cooling, so that large temperature differences do not occur in various parts of the elastomer article in the mold. In addition, not only can a uniform degree of vulcanization be obtained by effectively cooling without causing an undesirable temperature or pressure drop, but also troubles such as vulcanization delays can be reliably prevented.

Next, the second embodiment is implemented as follows.

That is, immediately after the heating medium supply process is completed, the "output" side pipe 115 with the orifice 119 is opened for a predetermined period of time, and a part of the heating medium, that is, steam filling the internal space 120 of the tire 104 in the mold 102 is removed. Or, the entire amount is discharged, and along with the discharge, E enters the outside of the inner space 120 of the tire 104.
Pressurized fluid that has not been heated from the side pipe 106 (new gas that has come out of the gas tank and has never entered the tire internal space 120), or in the case of a vulcanizer that has a forced circulation pipe 109, use this pipe 109. used gas)
instead flows into the tire internal space 120 and the space 1
20, that is, after replacing or replacing the high temperature heating medium in the tire internal space 120 with a low temperature pressurized medium, the "output" side piping is closed to perform so-called gas purge cooling.

The cooling effect of the tire inside the mold is determined by the diameter of the orifice installed in the "output" side piping and the gas purge cooling time.
When determining the cooling effect, the first point is to what extent the pressure in the tire internal space can be lowered. This pressure drop tolerance level (e.g. approximately 7 kg/cIl)
If l) is broken, bareness or porosity will occur, or problems with double molding of sidewall lettering will occur. Next, the original pressure of the gas to be purged (
For example, 21 kg/cd) and orifice diameter (for example, 5 mm)
) and the diameter of the gas inlet side pipe (for example, 16 ma+), the desired pressure in the tire internal space during gas purge cooling (for example, 19 kg/cIll) can be set.

To determine the gas purge time, first decide on the diameter of the orifice that will keep the pressure drop in the tire's internal space within the allowable range, then attach this orifice to the "output" side piping, actually gas vulcanize the tire, and perform gas purge cooling. By repeating experiments to collect tire temperature data, it is possible to experimentally determine how many orifices and how many minutes gayu purge should be performed in order to obtain the desired cooling effect.

It should be noted that it can be easily confirmed from the pressure graph whether the high temperature fluid in the inner space of the tire in the mold has been reliably replaced with low temperature fluid by the gas purge.

Next, as shown in FIGS. 1 and 5(A), a case will be described in which a light truck tire having a tire size of 205R16 and equipped with a polyester carcass ply is gas-cured using a BOM vulcanizer (temperature: 160° C.). After installing an orifice with a diameter of 5 mm at position W of the gas exhaust pipe 115, close the valves ■, ~V, on the "output" side piping, and open the valve ■2 on the "in" side piping to increase the pressure to 14 kg/cmz. After supplying steam for a reference time of 5 minutes, close valve V2 to stop supplying steam, and open valves ■ and ■4 to supply gas at a pressure of 19 kg/c and a temperature of 40°C for 30 seconds. Then, perform gas purge cooling as shown in FIG. 5(A). That is, only valve 4 of the gas exhaust pipe 115 is opened to exhaust (release to the atmosphere) a part or all of the heating medium (pressure 14 kg/cd) in the tire internal space 120, and the pressure is 19 kg/cd. Gas at a temperature of 40° C. flows into the tire internal space 120 and fills it. After 30 seconds (5th
As shown in FIG. The temperature of the inner liner can be, for example, 178°C or less at the sidewall A on the upper mold side, and it is also possible to raise the temperature at the bead part B on the lower mold side, for example, where vulcanization is delayed (see Fig. 5 (A). ) and (B)
comparison). Valve (4) of the gas discharge pipe 115 is closed, and then gas is continued to be supplied and a normal pressurized medium supply process begins.

At this time, the pressure in the tire internal space 120 is 21 kg/C
+a, and the temperature of the tire inner liner has decreased to a level of approximately 170°C at the upper sidewall A, for example. On the other hand, the temperature of the bead portion B on the lower mold side increases significantly faster than in the example shown in FIG. 5(C) using the general gas vulcanization method. After 11.5 minutes, the valve Vl of the gas supply pipe 113 is closed to stop the gas supply, and the valve V4 of the gas discharge pipe 115 is released to exhaust the gas from the tire internal space 120 to make the pressure zero, and then vacuum Then, the plug 103 is deflated and removed from the tire, and then the mold 102a is released and the vulcanized tire 2 is taken out to complete the entire vulcanization process.

As described above, in the second embodiment, immediately after the heating medium supply process for gas vulcanization of an elastomer article, and before switching to the pressurized medium supply process, the "output" side piping of the vulcanizer is connected for a predetermined period of time to control the flow rate by using an orifice. Since the structure is configured to perform so-called gas purge cooling by squeezing and releasing part or all of the heating medium, there is no large temperature difference in each part of the elastomer article in the mold, and there is no undesirable pressure drop. 《By effectively suppressing the excessive rise in temperature of the upper mold corresponding part and promoting the temperature rise of the lower mold corresponding part, vulcanization of the lower mold corresponding part, where vulcanization is delayed, is accelerated, vulcanization time is shortened, and vulcanization is uniform. You can measure sulfur.

In addition, Table 1 below shows the results of Example 5 (A) and Comparative Example (1).
)(2) and FIGS. 5(B) and 5(C) comparatively show the actually determined vulcanization time and the adhesion performance between the carcass part compound and the ply. From this table, the example shows that the vulcanization time can be shortened by 2 minutes compared to the normal vulcanization method example (comparative example (2)), and the same heating process (steam Compared to Comparative Example (1) in which the process) time was set, the tire performance can be improved.

Furthermore, it can be seen that the difference between the upper and lower temperatures during vulcanization can be reduced and uniform vulcanization can be achieved.

Part-1-. Table 11 (Effects) The present invention provides a method for vulcanizing an elastomer article, which includes a heating medium supply step and a pressurized medium supply step following this step, in which the elastomer article is vulcanized at least once in a mold for a predetermined period of time. A configuration in which a part or all of the heating medium or heated mixed fluid filling the internal space of the elastomeric article is discharged and replaced with a cold pressurized medium to cool the temperature of the elastomeric article to a desired level. In the first embodiment, the heated mixed fluid is replaced with a low-temperature pressurized medium during and/or after the pressurized medium supply process, so that each of the elastomer articles in the mold is Not only can you achieve a uniform degree of vulcanization by effectively cooling without creating large temperature differences or undesirable pressure drops in different parts, but you can also reliably prevent problems such as vulcanization delays. can do.

In addition, in the second embodiment, the heating medium is replaced with a low-temperature pressurizing medium immediately after the heating medium supplying process ends and before switching to the pressurizing medium supplying process, so that the heating medium is replaced with a low-temperature pressurizing medium at each location of the elastomer article in the mold. without creating large temperature differences,
In addition, by effectively suppressing the excessive rise in temperature of the upper mold corresponding part without causing an inconvenient pressure drop, and promoting the temperature rise of the lower mold corresponding part, vulcanization of the lower mold corresponding part, where vulcanization is delayed, is accelerated. , shortening of vulcanization time and uniform vulcanization can be achieved.

[Brief explanation of drawings]

FIG. 1(A) is a partial right half cross-sectional view of a tire vulcanizer used to carry out the method of the present invention, and an explanatory diagram showing a state in which an orifice is provided in the "output" side piping of the piping system in the machine; Figure (B
) is an explanatory diagram showing a state in which an orifice is provided in the "output" side piping when recovering gas in the vulcanizer of FIG. 1(A),
Figure 2 (A) is a graph showing the relationship between temperature and time when gas purge cooling is performed in the gas supply process, and Figure 2 (B) is a graph showing the relationship between temperature and time when gas purge cooling is performed after the gas supply process. Figure 3 is a graph showing the temperature difference between the upper sidewall and the lower sidewall of the tire in the mold when gas barge cooling is performed twice in the gas supply process, Figure 4 5(A) is a graph showing the temperature difference between the upper sidewall and the lower sidewall of the tire in the mold after gas vulcanization using the conventional cooling method. Figure 5 (B) shows the relationship between temperature and time when the heating process is carried out immediately after the completion of the heating medium supply process. The graph shown in Figure 5 (C) is a graph of temperature and time when gas purge cooling is not performed and the heating process time is set to the normal (preventing excessive rise in temperature of the upper mold) time, Figure 6. (A) is a partial cross-sectional view of a vulcanizer for performing gas vulcanization using a conventional cooling method and an explanatory diagram showing the piping system inside the machine. FIG. 102... Mold, 103... Bladder, 104...
・Raw tire, 107... "Out" side piping, 10B...
・"Inlet" side piping, 109... Forced circulation piping, 113
...Gas (pressurized medium) supply pipe, 114...Steam supply pipe, 115...Gas (mixed fluid) discharge (recovery) pipe, 119... orifice, 12
0...Tire internal space.

Claims (5)

[Claims] (1) A method for vulcanizing an elastomer article, comprising a heating medium supply step and a pressurized medium supply step following this step, the method comprising filling the internal space of the elastomer article in a mold at least once for a predetermined period of time. vulcanization of an elastomeric article, characterized in that part or all of the heated heating medium or heated mixed fluid is discharged and replaced by a cold pressurized medium to cool the temperature of the elastomeric article to a desired level; Method. (2) The method for vulcanizing an elastomer article according to claim 1, characterized in that the mixed fluid is replaced with a low-temperature pressurizing medium during or after the pressurizing medium supply step. (3) Immediately after the heating medium supply step and before switching to the pressurized medium supply step, the heating medium is replaced with a low-temperature pressurized medium, and after the replacement, the outlet piping of the vulcanizer is closed. A method for vulcanizing an elastomer article according to item 1. (4) Discharge the heating medium or mixed fluid from the vulcanizer.
A method of vulcanizing an elastomer article according to claim 1, 2 or 3, wherein the flow rate of the outlet side piping is reduced and opened. (5) Set the flow rate of the ``out'' side piping of the vulcanizer to the piping with a diameter of 20 mm.
5. The method of vulcanizing an elastomer article according to claim 4, wherein an orifice of less than mm is provided for squeezing.