JPS6054843B2 - Gas exhaust method during vulcanization of elastomer articles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for exhausting inert gas in a mold during the vulcanization of elastomeric articles, particularly tires using cords having a low melting point, such as nylon cords, as car gas.

Conventionally, the commonly used methods of vulcanizing tires, etc. are a steam vulcanization method using steam as a heating medium, a steam/heated water method using a combination of steam and heated water, and a heated water method using heated water. In either method, supply of pressure is essential until the end of the heating process, while regarding temperature, an appropriate amount of heat is supplied at the beginning of the heating process, and once the standard temperature necessary for vulcanization is reached, heat retention is sufficient. As shown in Figure 1, from the viewpoint of resource saving, steam or heated water and nitrogen are used in the heating process, as shown in Figure 1. The so-called steam gas vulcanization method, which is used in combination with an inert gas such as gas (which functions as a heat insulating medium), has been attracting attention.

This new method has running costs about 60 to 70% lower than conventional heating methods, and can be said to be a very advantageous vulcanization method. However, in the water cooling step that follows the heating step, as shown in Figure 2, Inert gas remains in the upper part 5 of the bladder 3 (inside the tire 4 if a bladder is not used), and the tire 4 in that area is not cooled sufficiently. In the case of tires having this type of tire, there is a problem that the strength of the cord decreases, resulting in an accident that damages the case during driving. The present invention aims to solve the above problems, and the method according to the present invention involves sequentially supplying inert gas and various vulcanizing media to the elastomer article loaded in a mold and vulcanizing it. In the process, at the end of the gas process in the second half of the inert heating process, high-pressure thermal fluid is blown into the tire for a short period of time to forcefully exhaust the inert gas inside the tire. It is characterized by the fact that no inert gas remains.

The present invention will be explained in detail below with reference to the drawings.

Elastomeric articles include, for example, those having components made of low melting point cords, such as tires having a carcass of 6-nylon cords.

The thermal fluid is, for example, steam.

As shown in FIG. 2, the vulcanizing device having a plug supports a plug 3 with a piston rod 6, an upper bladder ring 7, and a lower bladder ring 8, and also supports a vulcanizer made of an upper mold 1 and a lower mold 2. The tire 4 loaded in the mold is pressed against the inner surface of the mold by the expansion action of the plug 3, and the lower bladder ring 8 is provided with a go pipe 9 for supplying steam, etc. A return pipe 10 is provided for discharging vulcanizing media such as steam, inert gas, cooling water, etc. from each pipe 9, 10 in a sequential manner.
In the evacuation process, the tire 4 is vulcanized, and after vulcanization, the upper mold 1 is raised, and then the piston rod 6 is raised to remove the tire 4 from the lower mold 2, and in the evacuation process, the plug 3 is deflated and the tire is removed. 4 is taken out from the mold.

Note that the method of the present invention can also be applied to a vulcanization apparatus without a plug. In FIG. 3 showing the vulcanization process of the present invention, the gas process during the heating process (for example, a 175SR14 size tie.
At the end of the test (for example, 5 minutes), the high-pressure thermal fluid, e.g., 10 k
Blow 91 cI of steam (steam pressure in the first steam process is 14k91 cIt, for example) into the plug-3 (tire 4 if there is no plug) and inactivate it! Most of the sexual gases are forced out. Of course, the steam pressure varies depending on the vulcanization bar, the type of tire, etc. In Fig. 4, which shows the supply and discharge states of inert gas and various vulcanizing media, in the steam forced discharge process, gas valve V1 is closed, exhaust valve V4 is open, and steam valve V2 is opened, allowing gas to flow from go pipe 9 into plug 3. The steam is blown, and the inert gas is forcibly discharged from the return pipe 10 together with the steam. After the discharge is completed, the steam valve V2 and the exhaust valve V4 are closed, and the cooling water valve V3 is closed.
Then, the return cooling/cooling water valve V, opens, and the process shifts to the normal water cooling water process.

By adding this forced steam discharge process, gas will not remain in the upper part 5 of the plug 3, and the cooling effect in the subsequent process will be good. If the strength of the nylon carcass cord (the part facing the clay mold during vulcanization) is 100, it is 77 when using the conventional steam or gas vulcanization method.
, a test result of 94 was obtained using the method of the present invention.

As is clear from the above explanation, the present invention
In the gas vulcanization method, at the end of the gas process, a high-pressure hot fluid is blown for a short period of time to forcefully exhaust the inert gas, which prevents cooling failures due to residual inert gas. It has become fully possible to perform steam gas vulcanization of a tire having a carcass made of a low melting point cord such as , 6-nylon, without reducing the strength of the carcass cord.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the process of conventional steam and gas vulcanization methods.
Fig. 2 is a cross-sectional view of the mold showing the state in which inert gas remains in the cooling process, Fig. 3 is a process explanatory diagram of the method of the present invention,
FIG. 4 is an explanatory diagram showing the supply and discharge states of various vulcanizing media in the method of the present invention. 3... Plug, 4... Tire, 5...
...Top inside the plug, 9...Co piping, 10...Return piping.

Claims (1)

[Claims] 1. In the process of sequentially supplying an inert gas and various vulcanizing media to an elastomer article loaded in a mold for vulcanization, high pressure is applied at the end of the gas process in the latter half of the vulcanization process. An elastomer characterized by blowing hot fluid into the tire for a short period of time to forcibly discharge the inert gas inside the tire so that no inert gas remains in the upper part of the tire during the next water cooling process. Gas evacuation method during vulcanization of articles. 2. A method for discharging gas during vulcanization of an elastomer article according to claim 1, wherein various vulcanization media are supplied via a bladder. 3. A gas evacuation method during vulcanization of an elastomeric article according to claims 1 to 2, wherein the elastomeric article has a component consisting of a low melting point cord. 4. A gas evacuation method in vulcanization of an elastomer article according to claims 1 to 2, wherein the elastomer article is a tire having a nylon carcass.