Tire vulcanization method

Abstract

The invention provides a tire vulcanization method. According to the vulcanization process, a post-inflation device is not needed, the over-vulcanization degree of the tire sidewall can be effectively reduced, and the tire sidewall strength and the tire vulcanization uniformity are improved. According to the tire vulcanization method, the temperature of saturated steam in the steam chamber can be reduced, after vulcanization is finished, cold water is introduced into the capsule to replace superheated water so as to carry out first-stage cooling on the capsule, the interior of a tire blank is cooled, and the saturated steam in the steam chamber continues to be heated at low temperature for a period of time; in the second-section cooling process, saturated steam in the steam chamber is discharged, after heating of the saturated steam is stopped, cold water continues to be introduced into the capsule for cooling, and therefore the effect that post-inflation pressure maintaining slow cooling shaping is needed is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of tire vulcanization, and in particular to a tire vulcanization method. Background Art

[0002] In the traditional vulcanization process, the carcass reinforcement layer mostly uses polyester or nylon as the cord skeleton material, and its thermal shrinkage coefficient (CTE value is 5.5×10 -5 / ℃) can easily induce a significant shrinkage effect during the rapid cooling stage after vulcanization (cooling rate ΔT>80℃ / min), resulting in a high radial shrinkage rate of the finished tire. For this reason, conventional vulcanization processes require a post-inflation cooling and shaping device to reduce the shrinkage rate by maintaining pressure and slow cooling. However, in some cases, tire vulcanization manufacturers do not have a post-inflation cooling and shaping device. In the absence of a post-inflation cooling and shaping device, how to carry out vulcanization has become a difficult problem that needs to be solved in this field. Summary of the Invention

[0003] In view of this, the present invention provides a tire vulcanization method to solve the defects of the prior art.

[0004] The present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention provides a tire vulcanization method comprising the following steps:

[0006] Put the tire blank on the outside of the bladder;

[0007] Place the capsule in the mold, and pass superheated water into the capsule to expand the capsule, so that the capsule fits the inner side of the tire embryo and the outer side of the tire embryo fits the mold;

[0008] The mold is placed in the steam chamber while superheated water is continuously introduced into the bladder, and saturated steam is introduced into the steam chamber to perform saturated steam heating to vulcanize the tire blank;

[0009] After vulcanization, the superheated water in the capsule is discharged and cold water is passed into the capsule to cool the capsule for a period of time;

[0010] After the first stage of cooling, the saturated steam in the steam chamber is discharged, and cold water is continuously introduced into the capsule to perform the second stage of cooling.

[0011] Preferably, a water storage tank is provided outside the steam chamber, and a water outlet pipe and a water inlet pipe are provided on the water storage tank;

[0012] The capsule is provided with a nozzle and a drain pipe;

[0013] The water outlet pipe passes through the steam chamber and the mold and is connected to the nozzle;

[0014] The water inlet pipe passes through the steam chamber and the mold and is connected to the drain pipe;

[0015] The water storage tank stores cold water, which flows into the capsule through the water outlet pipe and the nozzle, and then flows into the water storage tank through the drain pipe and the water inlet pipe. The cold water circulates in the capsule and the water storage tank to cool the capsule for a period of time;

[0016] After the first stage of cooling, the saturated steam in the steam chamber is discharged, and the cold water continues to circulate in the capsule and water storage tank to perform the second stage of cooling on the capsule;

[0017] Among them, the temperature of cold water is ≤40℃, the first cooling time is 30 to 50 minutes, and the second cooling time is 20 to 40 minutes.

[0018] Preferably, in the step of introducing cold water into the capsule to cool the capsule, the pressure of the introduced cold water is ≥1.5 MPa.

[0019] Preferably, in the step of placing the capsule in the mold and introducing superheated water into the capsule to expand the capsule, the pressure of the introduced superheated water is 2.65 to 3.05 MPa.

[0020] Preferably, a water storage tank is provided outside the steam chamber, and a water outlet pipe and a water inlet pipe are provided on the water storage tank;

[0021] The capsule is provided with a nozzle and a drain pipe;

[0022] The water outlet pipe passes through the steam chamber and the mold and is connected to the nozzle;

[0023] The water inlet pipe passes through the steam chamber and the mold and is connected to the drain pipe;

[0024] The water tank stores superheated water, which flows into the capsule through the water outlet pipe and the nozzle to expand the capsule. The hot water flows into the water tank through the water outlet pipe and the water inlet pipe, and the superheated water circulates in the capsule and the water tank to heat the capsule.

[0025] The temperature of the superheated water is 170-176° C., and the circulation flow time is 70-180 minutes.

[0026] Preferably, in the step of introducing saturated steam into the steam chamber to perform saturated steam heating to vulcanize the tire blank, the introduced saturated steam temperature is 133-137° C. and the pressure is 0.22-0.26 MPa; the saturated steam heating time is 70-180 min.

[0027] The tire vulcanization method of the present invention has the following effects compared with the prior art:

[0028] The tire vulcanization method of the present invention can reduce the temperature of the saturated steam in the steam chamber (in a normal vulcanization process, the saturated steam temperature is 151°C, while in the present invention, the saturated steam temperature is only 133-137°C). After the vulcanization is completed, cold water is introduced into the capsule to replace the superheated water to perform a first-stage cooling of the capsule, thereby cooling the interior of the tire embryo, while the saturated steam in the steam chamber continues to be heated at a low temperature for a period of time; during the second-stage cooling, the saturated steam in the steam chamber is discharged, and after the saturated steam heating is stopped, cold water is continued to be introduced into the capsule for cooling; the tire vulcanization method of the present invention can effectively reduce the thermal mileage of the tire sidewall, reduce the degree of oversulfurization between the tire sidewall rubber and the sidewall carcass layer, and at the same time ensure the vulcanization degree of the inner layer rubber, thereby improving the tire sidewall strength and vulcanization uniformity ... The vulcanization process, without the need for a post-inflation device, can produce a tire with a size close to that obtained by a normal vulcanization process. The vulcanization process without post-inflation is feasible, and the resulting tire has good dimensional stability and low shrinkage. The performance indicators of the tire sidewall rubber compound produced by the vulcanization process, such as 100% and 300% modulus, tensile strength, Shore hardness, and permanent deformation at break, are all improved, and the bonding strength between the sidewall cord layers and between the sidewall cord layers is improved. The vulcanization process is used for the industrial production of agricultural tires and can effectively improve the quality of the tires, including dimensional stability, sidewall rubber compound performance, and bonding strength. The vulcanization process does not require a post-inflation device, can effectively reduce the degree of over-sulfurization of the tire sidewall, and improve the tire sidewall strength and the uniformity of tire vulcanization. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0030] Figure 1 A device used in a tire vulcanization method according to one embodiment of the present invention;

[0031] Figure 2 A device used in a tire vulcanization method according to another embodiment of the present invention;

[0032] Figure 3 Schematic diagram of the structure of a tire obtained according to the tire vulcanization method in Example 1;

[0033] Figure 4 The dimensions of the tire obtained according to the tire vulcanization method in Example 1, the tire obtained according to the normal vulcanization process in Comparative Example 1, and the tire according to the GB / T 2979-2017 tire design standard;

[0034] Figure 5 The physical properties of the lower rubber material and the sidewall rubber material of the tire obtained according to the tire vulcanization method in Example 1 and the tire obtained according to the normal vulcanization process in Comparative Example 1;

[0035] Figure 6 The median Shore hardness of the lower rubber compound and the median Shore hardness of the sidewall rubber compound of the tire obtained according to the tire vulcanization method of Example 1 (i.e., without post-inflation process) and the tire obtained according to the normal vulcanization process of Comparative Example 1;

[0036] Figure 7 It is the adhesion strength between the carcass cord layer and the sidewall of the tire obtained according to the tire vulcanization method in Example 1 (i.e., without post-inflation process) and the tire obtained according to the normal vulcanization process in Comparative Example 1. DETAILED DESCRIPTION

[0037] To facilitate understanding of the present invention, the present invention will be described more fully below in conjunction with the specific embodiments. Preferred embodiments of the present invention are provided in the specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0038] The present invention provides a tire vulcanization method, comprising the following steps:

[0039] S1. Place the tire blank on the outside of the bladder;

[0040] S2. Placing the capsule in the mold, and passing superheated water into the capsule to expand the capsule, so that the capsule is in contact with the inner side of the tire embryo, and the outer side of the tire embryo is in contact with the mold;

[0041] S3, placing the mold in the steam chamber while continuing to introduce superheated water into the bladder and introducing saturated steam into the steam chamber to perform saturated steam heating to vulcanize the tire blank;

[0042] S4. After vulcanization, the superheated water in the capsule is discharged and cold water is introduced into the capsule to cool the capsule for a period of time;

[0043] S5. After the first stage of cooling, the saturated steam in the steam chamber is discharged, and cold water is continuously introduced into the capsule to perform the second stage of cooling.

[0044] The tire vulcanization method of the present invention comprises the following steps: firstly, a tire embryo is placed on the outside of a bladder, and then the bladder is placed in a mold, and superheated water is introduced into the bladder. Under the action of the superheated water pressure, the bladder stretches outward, and expands and adheres tightly to the inner side of the tire embryo, and the outer side of the tire embryo adheres to the mold; the mold is placed in a steam chamber and superheated water is introduced into the bladder at the same time, and saturated steam is introduced into the steam chamber at the same time, the superheated water heats the bladder and then heats the tire embryo, and the saturated steam heats the mold to heat the tire embryo. In this process, hot water and saturated steam are used to heat the mold to heat the tire embryo, which is a tire vulcanization method. vulcanization process of the embryo; after vulcanization, the superheated water in the capsule is discharged, and cold water is introduced into the capsule to replace the superheated water; then the tire embryo is subjected to a two-stage cooling process. Specifically, the first stage is: cold water is introduced into the capsule to cool the tire embryo for a period of time. During the first cooling process, the saturated steam in the steam chamber still heats the tire embryo; after the first cooling, the saturated steam in the steam chamber is discharged, and cold water is continued to be introduced into the capsule to cool the capsule for a second period of time; wherein, during the first cooling, the synergistic effect of internal cooling and external temperature is formed to form a directional cooling gradient from the inside to the outside, thereby suppressing the shrinkage of the cord.

[0045] The beneficial effects of the present invention are as follows: the tire vulcanization method of the present invention can reduce the temperature of the saturated steam in the steam chamber. After the vulcanization is completed, cold water is introduced into the capsule to replace the superheated water to perform a first-stage cooling of the capsule, so that the temperature inside the tire embryo is reduced, while the saturated steam in the steam chamber continues to be heated at a low temperature for a period of time; during the second-stage cooling, the saturated steam in the steam chamber is discharged, and after the saturated steam heating is stopped, cold water is continued to be introduced into the capsule for cooling; the vulcanization process does not require a post-inflation device, and can effectively reduce the degree of oversulfurization of the tire sidewall, improve the tire sidewall strength and the uniformity of tire vulcanization.

[0046] In some embodiments, specific reference Figures 1-2 As shown, the mold 1 includes an upper mold 11 and a lower mold 12, which are detachably connected to each other. The upper mold 11 and the lower mold 12 are assembled to form the mold 1. After the tire embryo is placed on the outside of the capsule 2, the capsule 2 is placed in the lower mold 12, and the upper mold 11 is covered on the lower mold 12. At this time, the capsule 2 with the tire embryo is placed in the mold 1; a nozzle 21 and a drain pipe 22 are provided on the capsule 2, and a nozzle 21 and a drain pipe 22 are provided outside the steam chamber 3. A water tank 4 is provided with a water outlet pipe 41 and a water inlet pipe 42. The water outlet pipe 41 passes through the steam chamber 3 and the mold 1 and is connected to the nozzle 21. The water inlet pipe 42 passes through the steam chamber 3 and the mold 1 and is connected to the drain pipe 22. Cold water is stored in the water tank 4. The cold water flows into the capsule 2 through the water outlet pipe 41 and the nozzle 21, and then flows into the water tank 4 through the drain pipe 22 and the water inlet pipe 42. The cold water circulates in the capsule 2 and the water tank 4 to cool the capsule.

[0047] After the first stage of cooling, the saturated steam in the steam chamber 3 is discharged, and the cold water continues to circulate in the capsule and the water storage tank to perform the second stage of cooling on the capsule;

[0048] Among them, the temperature of cold water is ≤40℃, the first cooling time is 30 to 50 minutes, and the second cooling time is 20 to 40 minutes.

[0049] Specifically, the steam chamber 3 is provided with a steam inlet 31 and a steam outlet. Saturated steam (specifically water vapor) enters the steam chamber 3 through the steam inlet 31, and the water vapor in the steam chamber 3 is discharged through the steam outlet.

[0050] In some embodiments, in the step of again introducing cold water into the bladder 2 to expand the bladder and make the bladder adhere to the inner side of the tire blank, the pressure of the introduced cold water is ≥1.5 MPa.

[0051] In some embodiments, in the step of placing the capsule 2 in the mold 1 and introducing superheated water into the capsule 2 to expand the capsule, the pressure of the introduced water vapor is 2.65-3.05 MPa and the temperature of the superheated water is 170-176°C.

[0052] In some embodiments, superheated water is stored in the water tank 4. The superheated water flows into the capsule 2 through the water outlet pipe 41 and the nozzle 21, and then flows into the water tank 4 through the drain pipe 22 and the water inlet pipe 42. The superheated water circulates in the capsule 2 and the water tank 4 to heat the capsule.

[0053] The temperature of the superheated water is 170-176° C., and the circulation flow time is 80-180 minutes.

[0054] In some embodiments, the drain pipe 22 is provided with a water pump to increase the flow pressure of the cold water or hot water.

[0055] In some embodiments, a tire blank is placed on the outside of a capsule, the capsule is placed in a mold, the mold is placed in a steam chamber, and superheated water is stored in a water tank 4. The superheated water flows into the capsule 2 through the outlet pipe 41 and the nozzle 21 to expand the capsule. At the same time, superheated water continues to be introduced, and the superheated water flows into the water tank 4 through the drain pipe 22 and the water inlet pipe 42. The superheated water circulates in the capsule 2 and the water tank 4 to heat the capsule; while the superheated water heats the capsule 2, saturated steam is introduced into the steam chamber for saturated steam heating to vulcanize the tire blank.

[0056] In some embodiments, in the step of introducing saturated steam into the steam chamber 3 for steam heating to vulcanize the tire blank, the introduced saturated steam has a temperature of 133-137° C. and a pressure of 0.22-0.26 MPa; and the steam heating time is 80-180 min.

[0057] The tire vulcanization method of the present invention can effectively reduce the thermal mileage of the tire sidewall, reduce the oversulfurization degree between the tire sidewall rubber and the sidewall carcass layer, while ensuring the vulcanization degree of the inner layer rubber, and improving the tire sidewall strength and vulcanization uniformity. The post-inflation-free vulcanization process of the present invention is feasible, and the tire obtained has good dimensional stability and low shrinkage. The performance indicators of the 100% and 300% tensile stress, tensile strength, Shore hardness, and permanent deformation at break of the tire sidewall rubber material produced by the vulcanization process are all improved, and the bonding strength between the sidewall cord layers and between the sidewall cord layers is improved. The vulcanization process is used for the industrial production of agricultural tires and can effectively improve the quality of the tire, including dimensional stability, sidewall rubber material performance, and bonding strength. The vulcanization process does not require a post-inflation device, can effectively reduce the oversulfurization degree of the tire sidewall, and improve the tire sidewall strength and tire vulcanization uniformity.

[0058] The tire vulcanization method of the present invention is further illustrated below with reference to specific examples. This section further illustrates the present invention with reference to specific examples, but should not be construed as limiting the present invention. Unless otherwise specified, the techniques employed in the examples are conventional techniques well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment employed in the present invention are conventional in the art.

[0059] Example 1

[0060] This embodiment provides a tire vulcanization method using Figures 1-2 The device shown performs vulcanization, comprising the following steps:

[0061] S1. Place the tire blank on the outside of the bladder;

[0062] S2. Place the capsule in the mold and introduce superheated water at a temperature of 173° C. and a pressure of 2.85 MPa into the capsule to expand the capsule so that the capsule is in contact with the inner side of the tire blank and the outer side of the tire blank is in contact with the mold;

[0063] S3. Placing the mold in a steam chamber while introducing superheated water into the bladder, and introducing saturated steam at a temperature of 135° C. and a pressure of 0.24 MPa into the steam chamber to perform saturated steam heating to vulcanize the tire blank;

[0064] Specifically, the water tank stores superheated water, which flows into the capsule through the outlet pipe and the nozzle, and then flows into the water tank through the drain pipe and the water inlet pipe. The superheated water circulates in the capsule and the water tank to heat the capsule.

[0065] The temperature of the superheated water is 173°C and the pressure is 2.85 MPa. The superheated water circulates for 85 minutes. The saturated steam heating time in this stage is 85 minutes (the total saturated steam heating time is 85 minutes + 50 minutes (the saturated steam continues to heat for 50 minutes during the first stage of cooling in step S4) = 135 minutes).

[0066] S4. After vulcanization, the superheated water in the capsule is discharged and cold water is introduced into the capsule to replace the superheated water to cool the capsule for a period of time. At this time, the pressure in the capsule is 1.6 MPa.

[0067] S5. After the first stage of cooling, the saturated steam in the steam chamber is discharged, and cold water is continuously introduced into the capsule to perform the second stage of cooling.

[0068] S6. After the second stage of cooling, the cold water in the bladder is drained, the steam chamber is opened, the mold is opened, and the vulcanized tire blank is taken out;

[0069] Specifically, S5 is as follows: cold water is stored in the water tank, and the cold water flows into the capsule through the water outlet pipe and the nozzle, and then flows into the water tank through the drain pipe and the water inlet pipe. The cold water circulates in the capsule and the water tank to cool the capsule for a period of time;

[0070] After the first stage of cooling, the saturated steam in the steam chamber is discharged, and the cold water continues to circulate in the capsule and water storage tank to perform the second stage of cooling on the capsule;

[0071] The temperature of the cold water is 30°C, the first cooling time is 50 minutes, and the second cooling time is 40 minutes.

[0072] Example 2

[0073] This embodiment provides a tire vulcanization method using Figures 1-2 The device shown performs vulcanization, comprising the following steps:

[0074] S1. Place the tire blank on the outside of the bladder;

[0075] S2. Place the capsule in the mold and introduce superheated water at a temperature of 173° C. and a pressure of 2.85 MPa into the capsule to expand the capsule so that the capsule is in contact with the inner side of the tire blank and the outer side of the tire blank is in contact with the mold;

[0076] S3. Placing the mold in a steam chamber while introducing superheated water into the bladder, and introducing saturated steam at a temperature of 135° C. and a pressure of 0.24 MPa into the steam chamber to perform saturated steam heating to vulcanize the tire blank;

[0077] Specifically, the water tank stores superheated water, which flows into the capsule through the outlet pipe and the nozzle, and then flows into the water tank through the drain pipe and the water inlet pipe. The superheated water circulates in the capsule and the water tank to heat the capsule.

[0078] The temperature of the superheated water is 173°C and the pressure is 2.85 MPa. The superheated water circulates for 80 minutes. The saturated steam heating time in this stage is 80 minutes (the total saturated steam heating time is 80 minutes + 40 minutes (the saturated steam continues to heat for 40 minutes during the first stage of cooling in step S4) = 120 minutes).

[0079] S4. After vulcanization, the superheated water in the capsule is discharged and cold water is introduced into the capsule to replace the superheated water to cool the capsule for a period of time. At this time, the pressure in the capsule is 1.6 MPa.

[0080] S5. After the first stage of cooling, the saturated steam in the steam chamber is discharged, and cold water is continuously introduced into the capsule to perform the second stage of cooling.

[0081] S6. After the second stage of cooling, the cold water in the bladder is drained, the steam chamber is opened, the mold is opened, and the vulcanized tire blank is taken out;

[0082] Specifically, S5 is as follows: cold water is stored in the water tank, and the cold water flows into the capsule through the water outlet pipe and the nozzle, and then flows into the water tank through the drain pipe and the water inlet pipe. The cold water circulates in the capsule and the water tank to cool the capsule for a period of time;

[0083] After the first stage of cooling, the water vapor in the steam chamber is discharged, and the cold water continues to circulate in the capsule and the water storage tank to perform the second stage of cooling on the capsule;

[0084] Among them, the temperature of cold water is 30℃, the first cooling time is 40 minutes, and the second cooling time is 30 minutes.

[0085] Example 3

[0086] This embodiment provides a tire vulcanization method using Figures 1-2 The device shown performs vulcanization, comprising the following steps:

[0087] S1. Place the tire blank on the outside of the bladder;

[0088] S2. Place the capsule in the mold and introduce superheated water at a temperature of 173° C. and a pressure of 2.85 MPa into the capsule to expand the capsule so that the capsule is in contact with the inner side of the tire blank and the outer side of the tire blank is in contact with the mold;

[0089] S3. Placing the mold in a steam chamber while introducing superheated water into the bladder, and introducing saturated steam at a temperature of 135° C. and a pressure of 0.24 MPa into the steam chamber to perform saturated steam heating to vulcanize the tire blank;

[0090] Specifically, the water tank stores superheated water, which flows into the capsule through the outlet pipe and the nozzle, and then flows into the water tank through the drain pipe and the water inlet pipe. The superheated water circulates in the capsule and the water tank to heat the capsule.

[0091] The temperature of the superheated water is 173°C and the pressure is 2.85 MPa. The superheated water circulates for 90 minutes. The saturated steam heating time in this stage is 90 minutes (the total saturated steam heating time is 90 minutes + 50 minutes (the saturated steam continues to heat for 50 minutes during the first stage of cooling in step S4) = 140 minutes).

[0092] S4. After vulcanization, the superheated water in the capsule is discharged and cold water is introduced into the capsule to replace the superheated water to cool the capsule for a period of time. At this time, the pressure in the capsule is 1.6 MPa.

[0093] S5. After the first stage of cooling, the saturated steam in the steam chamber is discharged, and cold water is continuously introduced into the capsule to perform the second stage of cooling.

[0094] S6. After the second stage of cooling, the cold water in the bladder is drained, the steam chamber is opened, the mold is opened, and the vulcanized tire blank is taken out;

[0095] Specifically, S5 is as follows: cold water is stored in the water tank, and the cold water flows into the capsule through the water outlet pipe and the nozzle, and then flows into the water tank through the drain pipe and the water inlet pipe. The cold water circulates in the capsule and the water tank to cool the capsule for a period of time;

[0096] After the first stage of cooling, the water vapor in the steam chamber is discharged, and the cold water continues to circulate in the capsule and the water storage tank to perform the second stage of cooling on the capsule;

[0097] The temperature of the cold water is 30°C, the first cooling time is 50 minutes, and the second cooling time is 40 minutes.

[0098] Example 4

[0099] This embodiment provides a tire vulcanization method using Figures 1-2 The device shown performs vulcanization, comprising the following steps:

[0100] S1. Place the tire blank on the outside of the bladder;

[0101] S2. Place the capsule in the mold and introduce superheated water at a temperature of 173° C. and a pressure of 2.85 MPa into the capsule to expand the capsule so that the capsule is in contact with the inner side of the tire blank and the outer side of the tire blank is in contact with the mold;

[0102] S3. Placing the mold in a steam chamber while introducing superheated water into the bladder, and introducing saturated steam at a temperature of 135° C. and a pressure of 0.24 MPa into the steam chamber to perform saturated steam heating to vulcanize the tire blank;

[0103] Specifically, the water tank stores superheated water, which flows into the capsule through the outlet pipe and the nozzle, and then flows into the water tank through the drain pipe and the water inlet pipe. The superheated water circulates in the capsule and the water tank to heat the capsule.

[0104] The temperature of the superheated water is 173°C and the pressure is 2.85 MPa. The superheated water circulates for 70 minutes. The saturated steam heating time in this stage is 70 minutes (the total saturated steam heating time is 70 minutes + 30 minutes (the saturated steam continues to heat for 50 minutes during the first stage of cooling in step S4) = 100 minutes).

[0105] S4. After vulcanization, the superheated water in the capsule is discharged and cold water is introduced into the capsule to replace the superheated water to cool the capsule for a period of time. At this time, the pressure in the capsule is 1.6 MPa.

[0106] S5. After the first stage of cooling, the saturated steam in the steam chamber is discharged, and cold water is continuously introduced into the capsule to perform the second stage of cooling.

[0107] S6. After the second stage of cooling, the cold water in the bladder is drained, the steam chamber is opened, the mold is opened, and the vulcanized tire blank is taken out;

[0108] Specifically, S5 is as follows: cold water is stored in the water tank, and the cold water flows into the capsule through the water outlet pipe and the nozzle, and then flows into the water tank through the drain pipe and the water inlet pipe. The cold water circulates in the capsule and the water tank to cool the capsule for a period of time;

[0109] After the first stage of cooling, the water vapor in the steam chamber is discharged, and the cold water continues to circulate in the capsule and the water storage tank to perform the second stage of cooling on the capsule;

[0110] The temperature of the cold water is 30°C, the first cooling time is 30 minutes, and the second cooling time is 20 minutes.

[0111] Example 5

[0112] This embodiment provides a tire vulcanization method using Figures 1-2 The device shown performs vulcanization, comprising the following steps:

[0113] S1. Place the tire blank on the outside of the bladder;

[0114] S2. Place the capsule in the mold and introduce superheated water at a temperature of 173° C. and a pressure of 2.85 MPa into the capsule to expand the capsule so that the capsule is in contact with the inner side of the tire blank and the outer side of the tire blank is in contact with the mold;

[0115] S3. Placing the mold in a steam chamber while introducing superheated water into the bladder, and introducing saturated steam at a temperature of 135° C. and a pressure of 0.24 MPa into the steam chamber to perform saturated steam heating to vulcanize the tire blank;

[0116] Specifically, the water tank stores superheated water, which flows into the capsule through the outlet pipe and the nozzle, and then flows into the water tank through the drain pipe and the water inlet pipe. The superheated water circulates in the capsule and the water tank to heat the capsule.

[0117] The temperature of the superheated water is 173°C and the pressure is 2.85 MPa. The superheated water circulates for 77 minutes. The saturated steam heating time in this stage is 77 minutes (the total saturated steam heating time is 77 minutes + 30 minutes (the saturated steam continues to heat for 30 minutes during the first stage of cooling in step S4) = 107 minutes).

[0118] S4. After vulcanization, the superheated water in the capsule is discharged and cold water is introduced into the capsule to replace the superheated water to cool the capsule for a period of time. At this time, the pressure in the capsule is 1.6 MPa.

[0119] S5. After the first stage of cooling, the saturated steam in the steam chamber is discharged, and cold water is continuously introduced into the capsule to perform the second stage of cooling.

[0120] S6. After the second stage of cooling, the cold water in the bladder is drained, the steam chamber is opened, the mold is opened, and the vulcanized tire blank is taken out;

[0121] Specifically, S5 is as follows: cold water is stored in the water tank, and the cold water flows into the capsule through the water outlet pipe and the nozzle, and then flows into the water tank through the drain pipe and the water inlet pipe. The cold water circulates in the capsule and the water tank to cool the capsule for a period of time;

[0122] After the first stage of cooling, the water vapor in the steam chamber is discharged, and the cold water continues to circulate in the capsule and the water storage tank to perform the second stage of cooling on the capsule;

[0123] Among them, the temperature of cold water is 30℃, the first cooling time is 30min, and the second cooling time is 30min.

[0124] Comparative Example 1

[0125] This comparative example provides a normal vulcanization process (wherein steps S1 to S4 adopt the Figures 1-2 The device shown in the figure is used for vulcanization), comprising the following steps:

[0126] S1. Place the tire blank on the outside of the bladder;

[0127] S2. Place the capsule in the mold and introduce superheated water at a temperature of 173° C. and a pressure of 2.85 MPa into the capsule to expand the capsule so that the capsule is in contact with the inner side of the tire blank and the outer side of the tire blank is in contact with the mold;

[0128] S3. Place the mold in the steam chamber and simultaneously introduce superheated water at a temperature of 173° C. and a pressure of 2.85 MPa into the bladder. Saturated steam at a temperature of 151° C. and a pressure of 0.40 MPa is introduced into the steam chamber to perform saturated steam heating to vulcanize the tire blank. The superheated water circulates for 85 minutes, and the saturated steam heating time is 85 minutes.

[0129] S4. After vulcanization, the superheated water in the capsule is discharged, and the saturated steam in the steam chamber is discharged at the same time, and the saturated steam heating is stopped; cold water is introduced into the capsule to replace the superheated water to cool the capsule. At this time, the pressure in the capsule is 1.6 MPa, the temperature of the cold water is 30°C, and the cooling time is 5 minutes;

[0130] S5. After cooling, drain the cold water in the capsule, open the steam chamber, open the mold, and take out the vulcanized tire blank;

[0131] S6. The vulcanized tire blank is subjected to pressure maintenance and slow cooling using a post-inflation device. Specifically, the post-inflation device is a device used to inflate, cool, and shape the tire after vulcanization. Its main function is to inflate and maintain a certain pressure in the tire after vulcanization to ensure that the tire maintains the correct shape, size, and physical properties during the slow cooling process, preventing deformation due to uneven cooling or other factors, thereby ensuring tire quality.

[0132] Among them, the inflation pressure is 0.35Mpa, and the slow cooling method is: self-heating and cooling at room temperature (25℃).

[0133] Specifically, Figure 3 is a schematic structural diagram of a tire obtained according to the tire vulcanization method in Example 1, Figure 3 The inner side is the side where the tire embryo and the bladder are nested during vulcanization, that is, the layer where the tire embryo and the bladder are in contact; Figure 3 The positions of the tread underlayer rubber, carcass buffer layer, sidewall rubber, and carcass cord layer are shown in the figure.

[0134] The tire obtained by the tire vulcanization method in Example 1 and the tire obtained by the normal vulcanization process in Comparative Example 1 both use nylon as the cord skeleton material for the carcass reinforcement layer (the carcass buffer layer and the carcass cord layer are the reinforcement layers).

[0135] Performance Testing

[0136] Figure 4 The dimensions of the tire obtained according to the tire vulcanization method in Example 1, the tire obtained according to the normal vulcanization process in Comparative Example 1, and the tire according to the GB / T 2979-2017 tire design standard.

[0137] Figure 4 The process without post-inflation is Example 1, and the normal process is Comparative Example 1.

[0138] Figure 4 The median groove depth refers to the vertical depth of the grooves between the tread blocks of the tire, and the outer diameter refers to the maximum diameter of the tire cross-section when the tire is installed on a standard rim and inflated to the standard pressure.

[0139] from Figure 4 It can be seen that the outer diameter of the tire according to the GB / T 2979-2017 tire design standard is 1550 mm, the outer diameter of the tire obtained according to the tire vulcanization method in Example 1 is 1590 mm, and the outer diameter of the tire obtained according to the normal vulcanization process in Comparative Example 1 is 1573 mm; the average tread groove depth of the tire according to the GB / T 2979-2017 tire design standard is 41.5 mm, the average tread groove depth of the tire obtained according to the tire vulcanization method in Example 1 is 36.5 mm, and the average tread groove depth of the tire obtained according to the normal vulcanization process in Comparative Example 1 is 34.7 mm; the outer diameters and average groove depths of the tires obtained by the methods in Example 1 and Comparative Example 1 are relatively close; this shows that the post-inflation-free vulcanization process of the present invention, without the need for a post-inflation device, is close to the size of the tire obtained by the normal vulcanization process, the post-inflation-free vulcanization process of the present invention is feasible, and the resulting tire has good dimensional stability and low shrinkage (close to the size of the tire designed in GB / T 2979-2017, with low shrinkage).

[0140] Figure 5 The physical properties of the lower layer rubber material and the sidewall rubber material of the tire obtained according to the tire vulcanization method in Example 1 and the tire obtained according to the normal vulcanization process in Comparative Example 1. Figure 5 The process without post-inflation is Example 1, and the normal process is Comparative Example 1.

[0141] from Figure 5It can be seen that the median 100% tensile stress of the lower layer rubber material of the tire obtained according to the tire vulcanization method in Example 1 is 3.3 MPa, the median 300% tensile stress of the lower layer rubber material (i.e., the average value) is 11.1 MPa, the median tensile strength of the lower layer rubber material is 19.5 MPa, and the permanent deformation at break of the lower layer rubber material is 16%. The median 100% tensile stress of the sidewall rubber material is 2.3 MPa, the median 300% tensile stress of the sidewall rubber material is 8.3 MPa, the median tensile strength of the sidewall rubber material is 16.6 MPa, and the permanent deformation at break of the sidewall rubber material is 12%.

[0142] The median tensile stress at 100% of the lower layer rubber material of the tire obtained by the normal vulcanization process in Comparative Example 1 is 3.1 MPa, the median tensile stress at 300% of the lower layer rubber material is 10.2 MPa, the median tensile strength of the lower layer rubber material is 19 MPa, and the permanent deformation at break of the lower layer rubber material is 14%. The median tensile stress at 100% of the sidewall rubber material is 2.1 MPa, the median tensile stress at 300% of the sidewall rubber material is 7.2 MPa, the median tensile strength of the sidewall rubber material is 15.2 MPa, and the permanent deformation at break of the sidewall rubber material is 10%.

[0143] As can be seen from the above, the tires produced by the present invention using the non-post-inflation vulcanization process have improved various performance indicators of the sidewall rubber material, including: 100% and 300% modulus stress, tensile strength, Shore hardness, and permanent deformation at break. This shows that the non-post-inflation vulcanization process can effectively reduce the degree of over-sulfurization of the sidewall and improve the strength and wear resistance of the sidewall rubber material.

[0144] Figure 6 The median Shore hardness of the lower rubber compound of the tire obtained according to the tire vulcanization method in Example 1 (i.e., without post-inflation process) and the tire obtained according to the normal vulcanization process in Comparative Example 1, as well as the median Shore hardness of the sidewall rubber compound.

[0145] from Figure 6 It can be seen that the Shore hardness of the lower layer rubber material of the tire obtained by the tire vulcanization method in Example 1 is median 62 degrees, and the Shore hardness of the lower layer rubber material of the tire obtained by the normal vulcanization process in Comparative Example 1 is median 61 degrees; the Shore hardness of the sidewall rubber material of the tire obtained by the tire vulcanization method in Example 1 is median 53 degrees, and the Shore hardness of the sidewall rubber material of the tire obtained by the normal vulcanization process in Comparative Example 1 is median 54 degrees; it can be seen that the Shore hardness of the tire vulcanized by the post-inflation-free process of the present invention is greater than the Shore hardness of the tire vulcanized by the normal vulcanization process.

[0146] Figure 7 It is the adhesion strength between the carcass cord layer and the sidewall of the tire obtained according to the tire vulcanization method in Example 1 (i.e., without post-inflation process) and the tire obtained according to the normal vulcanization process in Comparative Example 1.

[0147] from Figure 7 It can be seen that the bonding strength between the sidewall cord layer and the sidewall of the tire obtained by the tire vulcanization method in Example 1 (i.e., without post-inflation process) is 9.2 kN / m, while the bonding strength between the sidewall cord layer and the sidewall of the tire obtained by the normal vulcanization process in Comparative Example 1 is 8.9 kN / m; thus, it can be seen that the bonding strength between the sidewall cord layer and the sidewall of the tire obtained by the tire vulcanization method in Example 1 (i.e., without post-inflation process) is improved compared with the bonding strength of the normal vulcanization process.

[0148] Overall, the post-inflation-free vulcanization process can effectively improve the quality of agricultural tires, including dimensional stability, sidewall compound performance and bonding strength.

[0149] It can be understood that the various technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0150] The above are merely preferred embodiments of the present application and only specifically describe the technical principles of the present application. These descriptions are intended only to explain the principles of the present application and should not be construed in any way as limiting the scope of protection of the present application. Based on the explanations herein, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application, as well as other specific implementations of the present application that can be conceived by those skilled in the art without inventive effort, shall be included within the scope of protection of the present application.

Claims

1. A tire vulcanization method, characterized in that: The following steps are involved: Put the tire blank on the outside of the bladder; Place the capsule in the mold, and pass superheated water into the capsule to expand the capsule, so that the capsule fits the inner side of the tire embryo and the outer side of the tire embryo fits the mold; The mold is placed in the steam chamber while superheated water is continuously introduced into the bladder, and saturated steam is introduced into the steam chamber to perform saturated steam heating to vulcanize the tire blank; After vulcanization, the superheated water in the capsule is discharged and cold water is passed into the capsule to cool the capsule for a period of time; After the first stage of cooling, the saturated steam in the steam chamber is discharged, and cold water is continuously introduced into the capsule to perform the second stage of cooling.

2. The tire vulcanization method according to claim 1, wherein: A water storage tank is provided outside the steam chamber, and a water outlet pipe and a water inlet pipe are provided on the water storage tank; The capsule is provided with a nozzle and a drain pipe; The water outlet pipe passes through the steam chamber and the mold and is connected to the nozzle; The water inlet pipe passes through the steam chamber and the mold and is connected to the drain pipe; The water storage tank stores cold water, which flows into the capsule through the water outlet pipe and the nozzle, and then flows into the water storage tank through the drain pipe and the water inlet pipe. The cold water circulates in the capsule and the water storage tank to cool the capsule for a period of time; After the first stage of cooling, the saturated steam in the steam chamber is discharged, and the cold water continues to circulate in the capsule and water storage tank to perform the second stage of cooling on the capsule; Among them, the temperature of cold water is ≤40℃, the first cooling time is 30 to 50 minutes, and the second cooling time is 20 to 40 minutes.

3. The tire vulcanization method according to claim 1, wherein: In the step of introducing cold water into the capsule to cool the capsule for a period of time, the pressure of the introduced cold water is ≥1.5 MPa.

4. The tire vulcanization method according to claim 1, wherein: In the step of placing the capsule in a mold and introducing superheated water into the capsule to expand the capsule, the pressure of the introduced superheated water is 2.65 to 3.05 MPa and the temperature of the superheated water is 170 to 176°C.

5. The tire vulcanization method according to claim 1, wherein: A water storage tank is provided outside the steam chamber, and a water outlet pipe and a water inlet pipe are provided on the water storage tank; The capsule is provided with a nozzle and a drain pipe; The water outlet pipe passes through the steam chamber and the mold and is connected to the nozzle; The water inlet pipe passes through the steam chamber and the mold and is connected to the drain pipe; The water storage tank stores superheated water, which flows into the capsule through the water outlet pipe and the nozzle, and then flows into the water storage tank through the drain pipe and the water inlet pipe. The superheated water circulates in the capsule and the water storage tank to heat the capsule; The temperature of the superheated water is 170-176° C., and the circulation flow time is 70-180 minutes.

6. The tire vulcanization method according to claim 1, wherein: In the step of introducing saturated steam into the steam chamber to perform saturated steam heating to vulcanize the tire blank, the introduced saturated steam temperature is 133-137° C. and the pressure is 0.22-0.26 MPa; the saturated steam heating time is 70-180 minutes.

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