Engineering radial tire inner liner and production process and tear resistance detection method thereof

Abstract

The invention discloses an inner liner of an engineering radial tire, a production process of the inner liner and a tear resistance detection method of the inner liner, and relates to the technical field of tires. The technical scheme is as follows: (1) the airtight layer comprises the following components in parts by weight: 60-80 parts of brominated butyl rubber, 10-15 parts of natural rubber, 10-15 parts of chlorosulfonated polyethylene and 55-60 parts of carbon black; and (2) the exhaust line groove of the curing bladder is arc-shaped, the depth h 'is equal to 1.65-1.8 mm, the width W' is equal to 7.5-7.8 mm, the surface chamfer R1 'is equal to 3.2-3.5 mm, the bottom chamfer R2' of the groove is equal to 1.5-1.8 mm, and the sectional area of the groove is 5.5-6 mm < 2 >. The formula design of the inner liner of the tire is adjusted, and the tear resistance of the inner liner is improved; the exhaust line size design of the curing bladder is improved, the service life of the curing bladder can be prolonged, and aging and cracking of the groove position of the curing bladder are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of tires, and in particular to an airtight layer of an engineering radial tire, a production process thereof, and a method for detecting the tear resistance thereof. Background Art

[0002] At present, there are the following problems in the production process of engineering radial tires: Due to the imperfect formula design and the insufficient design of the bladder exhaust line during the vulcanization process, the tire is prone to problems when running in a high temperature and high humidity environment. Specifically, in the middle and late stages of tire use, the airtight layer at the root of the exhaust line in the tire (such as Figure 1 As shown in the figure, cracks will appear, and the occurrence of such cracks will directly lead to failure phenomena such as tire leakage and delamination, which seriously affects the performance of the tire.

[0003] It is worth noting that this problem gradually emerges during the use of the tire, causing great inconvenience to users. In addition, due to the lack of reasonable and effective simulation detection methods, it is impossible to accurately identify and effectively improve the tear resistance of the airtight layer of the finished tire during the production process. This undoubtedly increases the difficulty of tire quality control and further affects the overall mileage of the tire.

[0004] To address this problem, it is urgent to optimize the existing tire airtight layer formula design and improve the design of the capsule exhaust line during the vulcanization process to reduce the probability of cracks when the tire is running in a high temperature and high humidity environment. In addition, developing a set of scientific and reasonable simulation detection methods to effectively identify and improve the tear resistance of the finished tire airtight layer is the key to improving tire quality and extending tire service life. Only in this way can we provide users with safer and more reliable tire products and ensure driving safety. Summary of the invention

[0005] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art, to provide an engineering radial tire airtight layer and its production process and its tear resistance detection method, to adjust the formula design of the tire airtight layer, and to increase the tear resistance of the airtight layer; to improve the exhaust line size design of the vulcanization bladder, to extend the service life of the vulcanization bladder, and to reduce aging and cracking at the groove position of the vulcanization bladder.

[0006] The technical solution of the present invention is:

[0007] In a first aspect, the present invention provides a production process for an airtight layer of an engineering radial tire, wherein (1) the airtight layer comprises the following components in parts by weight: 60-80 parts of brominated butyl rubber, 10-15 parts of natural rubber, 10-15 parts of chlorosulfonated polyethylene, and 55-60 parts of carbon black; (2) the exhaust line groove of the vulcanization bladder is in an arc shape, with a depth of h'=1.65-1.8 mm, a width of W'=7.5-7.8 mm, a surface chamfer R1'=3.2-3.5 mm, a groove bottom chamfer R2'=1.5-1.8 mm, and a groove cross-sectional area of ​​5.5-6 mm 2 .

[0008] In a second aspect, the present invention provides an engineering radial tire airtight layer produced by the above-mentioned engineering radial tire airtight layer production process.

[0009] In a third aspect, the present invention provides a method for testing the tear resistance of the airtight layer of the above-mentioned engineering radial tire. In a constant temperature and humidity test box, a rubber flexure tester is used to test the tear resistance of the airtight layer sample at different temperatures and humidities.

[0010] Preferably, the detection temperature is 60-80° C., and the detection humidity is 60-80% RH.

[0011] Preferably, the rubber flexure testing machine is placed in a constant temperature and humidity test box, and the constant temperature and humidity test box is also provided with a temperature sensor, a humidity sensor, a temperature regulator and a humidity regulator.

[0012] Preferably, the airtight layer sample is subjected to a reciprocating motion at a rate of 280-300 times / min on a rubber flexure testing machine.

[0013] Preferably, during the test, a rubber flexure tester is used to test at least six airtight layer samples simultaneously.

[0014] Preferably, during the test, a rubber flexure tester is used to test twelve airtight layer samples simultaneously.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention adjusts the formula design of the tire airtight layer, and increases the tear resistance of the airtight layer; improves the exhaust line size design of the vulcanization bladder, which can extend the service life of the vulcanization bladder and reduce aging and cracking at the groove position of the vulcanization bladder; in addition, the establishment of a method for detecting the tear resistance of the airtight layer can realize the bending and stretching of the test rubber compound under the conditions of 60-80°C and 60-80%RH humidity to simulate the actual operating conditions of the engineering tire, and evaluate the change in the tear resistance of the adjusted airtight layer under different temperature and humidity conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1It is a schematic diagram of the structure of the airtight layer of an engineering radial tire.

[0018] Figure 2 It is a schematic structural diagram of the exhaust line groove of the vulcanizing bladder of the present invention.

[0019] Figure 3 It is a structural schematic diagram of a constant temperature and humidity test box and a rubber flexure test machine in the present invention.

[0020] Figure 4 The utility model is a structural schematic diagram of the exhaust line groove of the existing vulcanizing bladder.

[0021] In the figure, 1. airtight layer; 2. exhaust line groove; 3. constant temperature and humidity test chamber; 4. rubber flexure testing machine; 5. temperature sensor; 6. humidity sensor; 7. temperature regulator; 8. humidity regulator. DETAILED DESCRIPTION

[0022] In order to enable persons skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0023] Comparative Example 1

[0024] The airtight layer of Comparative Example 1 includes the following components in parts by weight: 80 parts of brominated butyl rubber, 20 parts of chlorosulfonated polyethylene, and 50 parts of carbon black.

[0025] like Figure 4 As shown, in the airtight layer sample of comparative example 1, the exhaust line size of the curing bladder is designed as follows: the exhaust line groove is columnar, with a depth of h = 2mm, a width of W = 3mm, a surface chamfer R1 = 0.3mm, a groove bottom chamfer R2 = 1mm, and a groove cross-sectional area of ​​5.61mm 2 .

[0026] Comparative Example 2

[0027] The airtight layer of Comparative Example 2 includes the following components in parts by weight: 80 parts of brominated butyl rubber, 10 parts of natural rubber, 10 parts of chlorosulfonated polyethylene, and 55 parts of carbon black.

[0028] like Figure 4 As shown, in the airtight layer sample of comparative example 2, the exhaust line size of the curing bladder is designed as follows: the exhaust line groove is columnar, with a depth of h = 2mm, a width of W = 3mm, a surface chamfer R1 = 0.3mm, a groove bottom chamfer R2 = 1mm, and a groove cross-sectional area of ​​5.61mm 2 .

[0029] Comparative Example 3

[0030] The airtight layer of Comparative Example 3 includes the following components in parts by weight: 80 parts of brominated butyl rubber, 20 parts of chlorosulfonated polyethylene, and 50 parts of carbon black.

[0031] like Figure 2 As shown, in the airtight layer sample of comparative example 1, the exhaust line size of the vulcanization bladder is designed as follows: the exhaust line groove is arc-shaped, and the airtight layer sample size has a depth of h'=1.7 mm, a width of W'=7.7 mm, a surface chamfer R1'=3.3 mm, a groove bottom chamfer R2'=1.7 mm, and a groove cross-sectional area of ​​5.8 mm.

[0032] Example 1

[0033] The airtight layer of Example 1 includes the following components in parts by weight: 80 parts of brominated butyl rubber, 10 parts of natural rubber, 10 parts of chlorosulfonated polyethylene, and 55 parts of carbon black.

[0034] like Figure 2 As shown, in the airtight layer sample of Example 1, the exhaust line size of the vulcanization bladder is designed as follows: the exhaust line groove is arc-shaped, and the airtight layer sample size has a depth of h'=1.7mm, a width of W'=7.7mm, a surface chamfer R1'=3.3mm, a groove bottom chamfer R2'=1.7mm, and a groove cross-sectional area of ​​5.8mm.

[0035] Example 2

[0036] The airtight layer of Example 2 includes the following components in parts by weight: 80 parts of brominated butyl rubber, 10 parts of natural rubber, 10 parts of chlorosulfonated polyethylene, and 55 parts of carbon black.

[0037] like Figure 2 As shown, in the airtight layer sample of Example 2, the exhaust line size of the vulcanization bladder is designed as follows: the exhaust line groove is arc-shaped, and the airtight layer sample size has a depth of h'=1.65mm, a width of W'=7.5mm, a surface chamfer R1'=3.2mm, a groove bottom chamfer R2'=1.5mm, and a groove cross-sectional area of ​​5.5mm.

[0038] Example 3

[0039] The airtight layer of Example 3 includes the following components in parts by weight: 80 parts of brominated butyl rubber, 15 parts of natural rubber, 15 parts of chlorosulfonated polyethylene, and 60 parts of carbon black.

[0040] like Figure 2 As shown, in the airtight layer sample of Example 3, the exhaust line size of the vulcanization bladder is designed as follows: the exhaust line groove is arc-shaped, and the airtight layer sample size has a depth of h'=1.8mm, a width of W'=7.8mm, a surface chamfer R1'=3.5mm, a groove bottom chamfer R2'=1.8mm, and a groove cross-sectional area of ​​6mm.

[0041] Take 6 airtight layer samples from Comparative Examples 1-3 and Examples 1-3 respectively and place them in Figure 3 The rubber flexure tester (GOTECH high-speed rail testing instrument GT-7011-DM) in the constant temperature and humidity test box shown in the figure is equipped with a temperature sensor, a humidity sensor, a temperature regulator and a humidity regulator. The tear resistance test is performed under the normal working conditions of 60°C and 60%RH and the high temperature and humidity working conditions of 80°C and 80%RH. During the test, the airtight layer sample is reciprocated at 300 times / min on the rubber flexure tester to simulate the change of the tear resistance of the airtight layer under different working conditions. The test results are shown in Table 1:

[0042] Table 1 Test results of tear resistance of airtight layer samples of comparative examples 1-3 and embodiments 1-3 under different working conditions

[0043]

[0044]

[0045] It can be seen from Comparative Examples 1-2 in Table 1 that under normal working conditions, compared with the existing airtight layer formula, the airtight layer formula of Example 1 of the present invention increases the average tear strength of the airtight layer by 6%, and under high temperature and high humidity working conditions, it increases by 5.9%. This is because compared with Comparative Example 1, Comparative Example 2 increases the tear resistance of the airtight layer rubber itself by adding 10 parts of natural rubber, and at the same time, by adding 5 parts of carbon black, it is ensured that the air retention of the airtight layer will not decrease. It can be seen from Comparative Example 3 and Comparative Example 1 that under normal working conditions, compared with the existing exhaust line size design of the vulcanization bladder, the exhaust line size design of the vulcanization bladder of the present invention increases the average tear strength of the airtight layer by 3.1%, and under high temperature and high humidity working conditions, it increases by 3.5%. This is because compared with Comparative Example 1, Comparative Example 3 reduces the stress concentration at the root of the tire airtight layer exhaust line by reducing the groove depth and increasing the groove surface chamfer, thereby reducing the risk of airtight layer cracking during the use of the finished tire; at the same time, the exhaust line width is increased to ensure that the groove cross-sectional area will not be reduced, thereby not affecting the exhaust performance during the actual vulcanization process of the tire. It can be seen from Examples 1-3 and Comparative Example 1 that under normal working conditions, compared with the exhaust line size of the existing vulcanization bladder and the existing airtight layer formula design, the exhaust line size design of the vulcanization bladder and the airtight layer formula design of the present invention increase the average tear strength of the airtight layer by 8-8.6%, and under high temperature and high humidity working conditions, it increases by 8.9-9.1%.

[0046] In summary, the present invention can improve the tear resistance of the airtight layer under normal working conditions and high temperature and high humidity working conditions by redesigning the airtight layer formula and the exhaust line size of the vulcanization bladder.

Claims

1. A production process for an engineering radial tire airtight layer, characterized in that: (1) The airtight layer comprises the following components in parts by weight: 60-80 parts of brominated butyl rubber, 10-15 parts of natural rubber, 10-15 parts of chlorosulfonated polyethylene, and 55-60 parts of carbon black; (2) The exhaust line groove of the curing bladder is in an arc shape, with a depth of h'=1.65-1.8mm, a width of W'=7.5-7.8mm, a surface chamfer R1'=3.2-3.5mm, a groove bottom chamfer R2'=1.5-1.8mm, and a groove cross-sectional area of ​​5.5-6mm 2 .

2. The engineering radial tire airtight layer produced by the engineering radial tire airtight layer production process as claimed in claim 1.

3. The method for detecting the tear resistance of the airtight layer of an engineering radial tire according to claim 2, characterized in that: In a constant temperature and humidity test chamber, a rubber flexure tester is used to test the tear resistance of the airtight layer samples at different temperatures and humidities.

4. The method for detecting the tear resistance of the airtight layer of an engineering radial tire according to claim 3, characterized in that: The detection temperature is 60-80°C, and the detection humidity is 60-80%RH.

5. The method for detecting the tear resistance of the airtight layer of an engineering radial tire according to claim 3, characterized in that: The rubber flexure tester is placed in a constant temperature and humidity test box, and the constant temperature and humidity test box is also provided with a temperature sensor, a humidity sensor, a temperature regulator and a humidity regulator.

6. The method for detecting the tear resistance of the airtight layer of an engineering radial tire according to claim 3, characterized in that: The airtight layer sample is subjected to a reciprocating motion of 280-300 times / min on a rubber flexure testing machine.

7. The method for detecting the tear resistance of the airtight layer of an engineering radial tire according to claim 3, characterized in that: During the test, at least six airtight layer specimens are tested simultaneously using a rubber flexure testing machine.

8. The method for detecting the tear resistance of the airtight layer of an engineering radial tire according to claim 7, characterized in that: During the test, a rubber flexure testing machine was used to test twelve airtight layer specimens simultaneously.

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