KR20030020583A - Curer for T.B-Radial Tires and Curing Method - Google Patents

Abstract

PURPOSE: A vulcanizer and vulcanizing method of a TB(Truck and Bus) radial tire is provided to improve quality and productivity by making a bladder thin instead of lowering quantity of heat to the inner bladder as well as increasing temperature of an outer mold. CONSTITUTION: A vulcanizer of a TB(Truck and Bus) radial tire comprises a tire mold and a bladder. The tire mold is formed to the outside. The bladder is formed to the inside of the tire mold. The bladder is thin from 4.0 to 10.0 millimeters in thickness. Vulcanizing temperature is advisable from 130 to 160 centigrade degrees. Steam and nitrogen gas of 7 to 25 kilograms is used as an internal pressure medium. Thereby, vulcanizing time is reduced and quality is improved.

Description

Curer for T.B-Radial Tires and Curing Method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vulcanizer and a vulcanization method for high temperature vulcanization of T.B truck and bus radial tires for large vehicles such as trucks and buses.

Until now, the amount of heat required for vulcanization of a tire uses the amount of heat transferred from the mold on the outside of the tire and the bladder on the inside (see FIG. 1). In order to improve the vulcanization productivity, it is necessary to increase the temperature of the outer mold or increase the amount of heat supplied from the inner bladder, but simply increasing the amount of heat supplied will have an adverse effect on tire quality.

In the case of simply increasing the supply heat, the tread / belt separation between the tires is caused by the decrease in the adhesive strength between rubbers, and the decrease in the adhesive strength is caused by excessive rubber due to excessive calorie heat. Can be generated. Therefore, simply increasing the supply of heat can cause a drop in belt adhesion, which adversely affects tire quality.

An object of the present invention is to solve the structural problems of the conventional vulcanization method as described above, while increasing the temperature of the outer mold and lowering the amount of heat supplied from the inner bladder, the productivity and the reduction of the vulcanization time. The present invention provides a vulcanizer and a vulcanization method of a TB radial tire that can contribute to tire quality improvement.

1 is a cross-sectional view showing a vulcanizer for vulcanizing a tire;

Figure 2a is an MR-type partial cross-sectional view as a bladder according to the present invention,

Fig. 2B is a partial cross-sectional view of an NR type as bladder according to the present invention.

Hereinafter, the technical configuration of the present invention in detail.

The vulcanizer of the TB radial tire of the present invention is a thin bladder in which the thickness of the bladder is thinly formed in the vulcanizer of the TB radial tire composed of a tire mold formed on the outside and a bladder provided inside the tire mold. In addition, the thickness of the thin bladder is characterized in that the 4.0 to 10.0mm.

On the other hand, when vulcanized, the vulcanization temperature is vulcanized in the range of 130 ° C. to 160 ° C., and at this time, 7 to 25 kg of steam and nitrogen (N ₂ ) gas are used as the pressure-resistant medium.

When the T.B radial tire is vulcanized by the vulcanizer and the method of the above structure, the vulcanization time can be shortened while obtaining stability and productivity improvement of the tire quality.

In order to show this, when the vulcanization external temperature was increased, the case where the thin bladder was used while increasing the vulcanization external temperature and reducing the supply time of the internal pressure supply medium, and also increasing the vulcanization external temperature and the supply time of the internal pressure supply medium was tested. The results according to the test are shown in Table 1, Table 2 and Table 3.

Conventional method Comparative example Vulcanization outside temperature (℃) 139 143 Bladder Plain bladder Plain bladder Pressure-resistant medium 17 Steam 17 Steam Test evaluation result The durability and physical properties of the conventional method have been reduced.

Table 1 above is the result of experiment by raising the vulcanization outside temperature. In this case, all of the bladder is using a conventional general bladder, the pressure-resistant medium is also using the steam of the same pressure. As a result of the test at a higher vulcanization temperature in the test, as shown in Table 1, it can be seen that the test evaluation results are lower than in the conventional method. The reason is that the heat transferred to the tire receives heat from the outer mold and the inner bladder. By simply increasing the heat of the outer mold and the heat received from the inner bladder, the rubber of the tire is supplied more than the required heat during the evaluation of the test without adjustment, resulting in a decrease in the physical properties of the rubber.

Conventional method Comparative example Vulcanization outside temperature (℃) 139 143 Bladder Plain bladder Plain bladder Pressure-resistant medium 17 Steam 14 Steam Test evaluation result Evaluation result compared to the conventional method, but increased process defect

Table 2 above is prepared for the test and the conventional method when the vulcanization external temperature is increased and the pressure resistant medium pressure is changed. The bladder is a general bladder, and the results of the vulcanization test using a high vulcanization outside temperature and a low medium compared to the conventional method in the test results obtained the same level of results as the conventional method as shown in Table 2, but the process failure due to low pressure-resistant medium pressure In addition, it can be seen that process instability increased. The amount of heat received by the tire is adjusted to the appropriate state by adjusting the outside and the inside, but the amount of steam supply, which is the inner heat transfer medium, is much reduced compared to the conventional one, and if a small amount of steam is supplied due to some mistakes in the process, a large amount of defect occurs. Since this is expected, the steam supply time needs to be kept above a certain time.

Conventional method Invention Vulcanization outside temperature (℃) 139 143 Bladder Plain bladder Lamination Bladder Pressure-resistant medium 17 Steam 17 Steam Test evaluation result Process stability is equal to the evaluation result compared to the conventional method

Table 3 shows the results of using the thin bladder while raising the vulcanization external temperature and applying the pressure resistant medium. The evaluation result shows that the process is stabilized while obtaining the same level of results as the conventional method. That is, it can be seen that by thinning the bladder gauge, the inner and outer heat transfer supplies are maintained at an appropriate level, and the steam supply time transferred from the inner bladder is stably secured.

Conventional method Invention 139 ℃ General Bladder 143 ℃ thin film bladder Total cure degree Temperature (℃) Total cure degree Temperature (℃) Belt edge 32.8 146.6 38.0 148.2 Tread surface 31.9 145.3 33.6 146.9 Hump 21.6 145.4 22.1 145.4

Table 4 shows the results of measuring and evaluating the tire internal temperature. Compared with the conventional method, the results of the test using higher vulcanization outside temperature and low pressure medium steam and sheet bladder show that the total vulcanization degree and the maximum temperature are not significantly different between the conventional method / test. In addition, as a result of evaluating the measurement of the internal temperature of the tire after applying the shortening of the vulcanization time, it can be seen that the stabilization of the quality could be maintained while maintaining the vulcanization degree and the maximum temperature similar to those of the conventional method. That is, it can be seen that by thinning the bladder gauge, the inner and outer heat transfer supplies are maintained at an appropriate level, and the steam supply time transferred from the inner bladder is stably secured.

As a result of the test evaluation as described above, the vulcanization time is reduced by 2 to 5% compared to the conventional method vulcanization time, which can bring about productivity improvement.

Meanwhile, one embodiment of the thin bladder used in the present invention is described below. Thin bladder is aimed at cost reduction through bladder gauge down and improved heat transfer from bladder. The comparative example of the gauge of the test bladder used by this invention is shown below.

part Plain bladder Bladder of the Invention Center 8.0 6.0 Hump 9.0 8.0

Table 5 above shows the variation of the gauge for the general bladder of the thin bladder used in the present invention. As a result of down gauges for general bladder, the productivity of the thin bladder increased by 2-5%. In other words, the time required for the tire to be cured is increased by using the thin bladder, so that the speed of vulcanization becomes 2 to 5% faster than before.

Thin bladders use different types of bladder depending on the type of vulcanizer used. One embodiment is shown in FIGS. 2A and 2B. Fig. 2A shows an MR bladder and Fig. 2B shows an NR bladder. These shapes differ depending on the driving method of the vulcanizer and do not have a special meaning.

As described above, the present invention can increase the vulcanization external temperature, and by using a thin plate bladder with the pressure medium pressure change, it is possible to shorten the vulcanization time, stabilize the quality, and improve productivity while maintaining an appropriate degree of vulcanization.

Claims (3)

In the vulcanizer of a TB radial tire composed of a tire mold formed on the outside and a bladder installed inside the tire mold, the bladder is composed of a thin plated bladder having a thin thickness. The thickness of 4.0-10.0mm, The vulcanizer of T. non-radial tire. A vulcanization method using the thin plate bladder of claim 1, wherein the vulcanization temperature is vulcanized in the range of 130 ° C to 160 ° C. The method of claim 2, A vulcanization method for a T. non-radial tire, characterized by using 7 to 25 kg of steam and nitrogen (N ₂ ) gas as the pressure resistant medium.