Method for testing surface autohension of sizing material

Abstract

The invention relates to the technical field of rubber material detection, and particularly discloses a rubber material surface autohension testing method which comprises the following steps: before autohension testing, adjusting a first scanning environment of a rubber processing analyzer for various samples with different formulas; during scanning, a Delay processing mode is adopted to execute specified time, and then samples with the same rubber material thickness are obtained; adjusting a second scanning environment of the rubber processing analyzer, respectively performing strain scanning on the samples of the various different formula samples, and scanning to obtain corresponding rheological data; drawing is conducted on the rheological data of different formula samples to obtain a corresponding storage modulus G'rheological curve, and the autohension of the sizing material is evaluated according to the storage moduli. The method overcomes the defects in the background technology, and effectively solves the problems that an existing autohension surface is incomplete in adhesion, long in testing period and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber material detection, in particular to a method for testing the self-adhesiveness of a rubber material surface. Background Art

[0002] In the rubber products industry, various lamination methods are commonly used to form tire blanks. The tackiness of the unvulcanized rubber surface is a crucial control point in the product molding process. For radial tire production, the tackiness of the molded rubber surface is particularly crucial. On the one hand, tack provides adhesion for the lamination of the various products, ensuring a secure fit and dimensional stability of the tire blank. On the other hand, if the adhesion is too tight, bubbles can form during tire blank molding, leading to further vulcanization. The resulting defects are often not discovered until after vulcanization, and sometimes even upon product delivery, resulting in significant economic losses.

[0003] Therefore, the size of rubber self-adhesion has both advantages and disadvantages for rubber processing. Characterizing the self-adhesion of rubber is one of the processing performance indicators. From the actual starting point of the molding process and to save costs, shorten the measurement time, measure data accurately and have good data reproducibility, the test method of rubber self-adhesion is very important, and it is of great significance to the quality control of rubber products.

[0004] At present, the industry's self-adhesive test methods mainly use two types of tests: butt adhesion test and peel adhesion test: The butt adhesion test involves pressing two pieces of rubber together under a certain pressure for a specified time, then measuring the maximum stress required to separate them. This maximum stress represents the adhesiveness of the rubber. Representative testing machines include the Wallace viscometer and the Thierry viscometer, as well as improved viscometers that combine the advantages of these two testing machines.

[0005] Peel Adhesion Test Method: First, the rubber compound is pressed into a film of a certain thickness. A reinforcing cloth is attached to one side and a polyester film is attached to the other side. A frame mold of a specific thickness is then pressed between hot plates at a certain temperature for a certain period of time. After the sample is left in place for a certain period of time, the peel test is performed. Before the test, the backing films of the two samples are peeled off and the adhesive surfaces are immediately bonded together. The samples are then pressed at a certain pressure for a certain period of time. The samples are then peeled off at a low tensile speed using a conventional tensile testing machine. The energy consumed per unit area on the peeled surface is measured to indicate the adhesiveness of the rubber compound.

[0006] The most basic prerequisite for obtaining the best self-adhesion is that the rubber or rubber sample blocks under study must achieve close contact over the entire surface. Both of the above methods have this defect. At the same time, the test cycle is long and the test reproducibility is poor. Therefore, it is urgently necessary to invent and design a test method for the self-adhesion of the rubber surface to solve the above problems. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for testing the self-adhesion of the rubber surface, which solves the problems that the test results proposed above cannot express the specific situation of the full surface contact self-adhesion, and the test cycle is long and the data reproducibility is poor.

[0008] In order to solve the above technical problems, the present invention provides a method for testing the self-adhesiveness of the surface of a rubber material. The specific testing method steps are as follows: S1. Before the self-adhesion test, adjust the first scanning environment of the rubber processing analyzer for samples of various formulas. During the scanning, use the delay processing method to execute the specified time to obtain samples with consistent rubber thickness; S2. Adjust the second scanning environment of the rubber processing analyzer, and then perform strain scanning on samples of various different formulations to obtain corresponding rheological data; S3. Plot the rheological data of samples with different formulations to obtain the corresponding storage modulus G' rheological curves, and evaluate the self-adhesion of the rubber compound according to the storage modulus.

[0009] Furthermore, in S1, the first scanning environment of the rubber processing analyzer is adjusted: the temperature detected by the rubber processing analyzer is 30-70° C., the scanning frequency is 0.1-5 Hz, and the strain value is 0.1-50%.

[0010] Furthermore, during the Delay process in S1, the prescribed time is 3 minutes to 5 minutes.

[0011] Furthermore, the samples of the multiple different formula samples in S1 are one of different rubber samples, different gasket rubber formula samples, different airtight layer samples and different styrene-butadiene rubber formula samples.

[0012] Furthermore, the rubber sample is one of natural rubber, styrene-butadiene rubber, BR9000 butadiene rubber, high Mooney butadiene rubber and brominated butyl rubber.

[0013] Furthermore, the pad rubber formula samples mainly include natural rubber, carbon black, antioxidant and plasticizer, and the plasticizer in different pad rubber formula samples is one of C5 resin, 203 resin and 204 resin.

[0014] Furthermore, the different airtight layer samples are one of the airtight layer samples with different parking times, such as 0d, 1d, 2d and 5d.

[0015] Furthermore, the styrene-butadiene rubber formula sample can be used as a tread formula, and the styrene-butadiene rubber tread formula sample contains styrene-butadiene rubber and a plasticizer, and the plasticizer in different styrene-butadiene rubber tread formula samples is one of unoiled resin, paraffin oil and rosin resin.

[0016] Furthermore, in S2, the second scanning environment of the rubber processing analyzer is adjusted: the detection temperature of each sample with different formulations is lowered to 40° C., the scanning frequency is 1 Hz, and the strain value is 1-10%.

[0017] The beneficial effects of the present invention are as follows: the method of the present invention uses the same first adjustment scanning environment before the self-adhesion test to ensure that each type of sample can maintain a consistent thickness test condition after mold closing, so that the measured data has good reproducibility and fast detection speed; At the same time, strain scanning is performed on samples of various different formula samples respectively, and the rheological data corresponding to the samples of various different formula samples are obtained by scanning. The corresponding storage modulus G' is obtained according to the rheological curve of each different formula sample. The self-adhesion of various samples is determined according to the storage modulus G', so as to determine the self-adhesion of different rubber samples and samples of rubber compounds filled with different component formulas, thereby improving product quality. It can effectively solve the problems of incomplete adhesion of existing self-adhesive surfaces, long test cycles, poor data reproducibility, and poor test judgment effects. It can be used to judge the self-adhesion of different rubber samples with different parking times on site, and quickly predict the change of rubber self-adhesion in advance to avoid the problem of poor adhesion or bubble generation during the vulcanization process. It can also provide a theoretical basis for selecting different raw rubbers and different plasticizers to enhance the self-adhesion of products.

[0018] The settings of rubber samples, gasket rubber formula samples, airtight layer samples and styrene-butadiene rubber formula samples, different components can meet the test requirements through the second scanning environment of this application, without repeated debugging, effectively improving the test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 is a rheological curve diagram of different rubbers expressed as storage modulus-strain in the present invention; Figure 2 The rheological curves of different resins added to different pad rubber formulations expressed as storage modulus-strain in the present invention are as follows; Figure 3 The rheological curve of the airtight layer at different storage times expressed as storage modulus-strain in the present invention; Figure 4 The rheological curve of the styrene-butadiene rubber tread formula in the present invention, expressed as storage modulus-strain, is shown when paraffin oil and rosin resin are added. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the invention in conjunction with the drawings in the specification of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] In a specific embodiment of the present invention, Figure 1-Figure 4 As shown, a method for testing the self-adhesiveness of the surface of a rubber material is specifically disclosed, and the specific testing method steps are as follows: Before the self-adhesion test, the temperature of the first scanning environment of the rubber processing analyzer was adjusted to 30-70°C, the scanning frequency was 0.1-5Hz, and the strain value was 0.1-50%. Samples of various formulations were placed in the mold cavity, and after the mold was closed, different formulation samples were obtained. The first scanning environment of the rubber processing analyzer was adjusted to ensure that the sample filled the mold cavity and the thickness of the samples of different formulations was consistent. The delay processing method was used during the scanning to obtain the rheological curve of the rubber compound after executing it for 3-5 minutes. The second scanning environment of samples with different formulations was tested at a temperature of 40°C, a scanning frequency of 1 Hz, and a strain value of 1-10%. Strain scans were then performed on samples of various formulations to obtain the corresponding rheological data. The rheological data of samples with different formulas were plotted to obtain the corresponding storage modulus G' rheological curves, and the self-adhesion of the rubber compound was evaluated based on the storage modulus.

[0023] The test specimens of the multiple different formula samples are one of different rubber samples, different cushion rubber formula samples, different airtight layer samples and different styrene-butadiene rubber formula samples; the rubber sample is one of natural rubber, styrene-butadiene rubber, BR9000 butadiene rubber, high Mooney butadiene rubber and brominated butyl rubber; the cushion rubber formula sample mainly includes natural rubber, carbon black, antioxidant and plasticizer, and the plasticizer in the different cushion rubber tread formula samples is one of C5 resin, 203 resin and 204 resin; the different airtight layer samples are one of the airtight layer samples with different parking times such as 0d, 1d, 2d and 5d; the styrene-butadiene rubber formula sample is used as the tread formula, and the styrene-butadiene rubber tread formula sample contains styrene-butadiene rubber and plasticizer, and the plasticizer in the different styrene-butadiene rubber formula samples is one of unoiled resin, paraffin oil and rosin resin.

[0024] During the use process, different tire components need to go through rubber mixing, extrusion, molding, and vulcanization. Each process has a certain parking time. As the parking time increases, the surface viscosity of the rubber will also change to a certain extent. Therefore, it is necessary to test the change of the viscosity of the rubber with the parking time. Therefore, strain scanning is performed on the air-inner layer samples with different parking times. The following is a specific example of testing the tested rubber samples, cushion rubber formula samples, air-inner layer samples with different parking times, and styrene-butadiene rubber formula samples: Example 1

[0025] The test method for the self-adhesion of the rubber surface is based on the RPA rubber dynamic self-adhesion evaluation method, which is carried out in the following steps: The first step, before the self-adhesion test, was to adjust the first scan environment of the rubber processing analyzer for various samples with different formulations. The temperature of the first scan environment of the rubber processing analyzer was adjusted to 30-70°C, the scanning frequency to 0.1-5Hz, and the strain value to 0.1-50%. The different rubber samples were filled into the mold cavity, and after the mold was closed, the samples of different thicknesses were obtained. The rheological curve of the rubber compound was obtained after scanning using the delay processing method for 3 minutes. The second step was to cool the RPA instrument's detection temperature to 40°C, set the scanning frequency to 1 Hz, and apply strain scans between 1 and 10% to various rubber samples. The samples included natural rubber, styrene-butadiene rubber, BR9000 butadiene rubber, high Mooney butadiene rubber, and bromobutyl rubber, and the rheological data was obtained. The third step is to plot the rheological data of different rubber samples to obtain the corresponding storage modulus G' rheological curves, and evaluate the self-adhesion of the rubber compound according to the storage modulus. The smaller the storage modulus G', the better the viscosity. Figure 1 It can be clearly seen that the viscosity of natural rubber is better than that of butadiene rubber, which is better than that of butyl rubber, which is better than that of styrene-butadiene rubber. Among them, the viscosity of ordinary butadiene rubber is better than that of high-Money butadiene rubber. Figure 1 It can be clearly judged that the self-adhesion obtained by this test method is consistent with the actual situation. Example 2

[0026] The specific test method steps for the test method of the self-adhesiveness of the rubber surface are as follows: In the first step, before the self-adhesion test, the first scanning environment temperature of the rubber processing analyzer was adjusted to 60°C, the scanning frequency to 0.1Hz, and the strain value to 0.7%. Various resin cushion glue samples with different formulations were placed in the mold cavity. After the mold was closed, samples of different resin cushion glue formulations with consistent thickness were obtained, ensuring that the samples filled the mold cavity. The rheological curve of the rubber compound was obtained after a delay process of 3 minutes during the scanning. The second step is to lower the detection temperature of the rubber processing analyzer (RPA) to 40°C, set the scanning frequency to 1 Hz, and the strain value to 2-10%. Then, strain scans are performed on various cushion rubber formula samples to obtain rheological data of the cushion rubber formula samples. The pad rubber formula samples mainly include natural rubber, carbon black, antioxidant and plasticizer. The plasticizer in different pad rubber formula samples is one of C5 resin, 203 resin and 204 resin. Usually C5 resin, 203 resin or 204 resin is used to improve the viscosity of the rubber compound. The third step is to plot the rheological data of the samples of different gasket glue formulas to obtain the corresponding storage modulus G' rheological curves, and evaluate the self-adhesion of the rubber compound according to the storage modulus. From the perspective of molecular structure, the viscosity of 204 resin is better than that of 203 resin and that of C5 resin. The smaller the storage modulus, the better the viscosity. Figure 2 It can be clearly judged that the self-adhesion obtained by this test method is consistent with the actual situation; Example 3

[0027] The specific test method steps for the test method of the self-adhesiveness of the rubber surface are as follows: In the first step, before the self-adhesion test, the temperature of the first scan environment of the rubber processing analyzer was adjusted to 60°C, the scanning frequency to 0.1Hz, and the strain value to 0.7%. The airtight layer samples with different dwell times were placed in the mold cavity. After the mold was closed, the airtight layer samples of uniform thickness were obtained, and the samples were ensured to fill the mold cavity. The rheological curve of the rubber compound was obtained after a delay process of 3 minutes during the scan. The second step was to lower the detection temperature of the rubber process analyzer (RPA) to 40°C, set the scanning frequency to 1 Hz, and apply strain scans to various innerliner samples with different storage times (0 days, 1 day, 2 days, and 5 days) to obtain the rheological data of the rubber. The third step is to plot the rheological data of the airtight layer samples with different storage times to obtain the corresponding storage modulus G' rheological curves. The self-adhesion of the rubber compound is evaluated according to the size of the storage modulus. Generally, as the storage time of the rubber compound increases, the self-adhesion of the rubber compound will gradually decrease. Figure 3 It can be clearly judged that the self-adhesion obtained by this test method is consistent with the actual situation. Example 4

[0028] Styrene-butadiene rubber formula can be used as a tread formula. Since the tread formula contains styrene-butadiene rubber, and the molecular chain of styrene-butadiene rubber contains benzene rings, its own viscosity is much worse than that of natural rubber. Therefore, the tread formula containing styrene-butadiene rubber generally uses oil and resin to increase the viscosity of the rubber. Now take the tread formula containing 80 parts of styrene-butadiene rubber, and compare the viscosity effects of the styrene-butadiene rubber tread formulas without oil and resin, with paraffin oil and with rosin resin.

[0029] The specific test method steps for the test method of the self-adhesiveness of the rubber surface are as follows: In the first step, before the self-adhesion test, the temperature of the first scan environment of the rubber processing analyzer was adjusted to 60°C, the scanning frequency to 0.1Hz, and the strain value to 0.7%. Styrene-butadiene rubber tread formulation samples with different oils or resins added were placed in the mold cavity. After the mold was closed, the styrene-butadiene rubber tread formulation samples filled the mold cavity. The thickness and size of the samples obtained by closing the mold were consistent. The rheological curve of the rubber compound was obtained after scanning using the delay processing method for 5 minutes. The second step was to lower the detection temperature of the rubber process analyzer (RPA) to 40°C, set the scanning frequency to 1 Hz, and adjust the strain value to 1-10%. Then, strain scans were performed on various styrene-butadiene rubber (SBR) formulations to obtain the rheological data of the rubber. The third step is to plot the rheological data of the samples of different styrene-butadiene rubber formulas to obtain the corresponding storage modulus G' rheological curves, and evaluate the self-adhesion of the rubber compound according to the storage modulus. from Figure 4 It can be seen from the figure that the viscosity of the styrene-butadiene rubber tread formula using rosin resin is better than that using paraffin oil, and using plasticizer is better than not using plasticizer. This provides us with a convenient and quick method to judge which plasticizer to choose.

[0030] The above disclosure is only a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for testing the self-adhesiveness of a rubber surface, characterized in that: The specific test method steps are as follows: S1. Before the self-adhesion test, adjust the first scanning environment of the rubber processing analyzer for samples of various formulas. During the scanning, use the delay processing method to execute the specified time to obtain samples with consistent rubber thickness; S2. Adjust the second scanning environment of the rubber processing analyzer, and then perform strain scanning on samples of various different formulations to obtain corresponding rheological data; S3. Plot the rheological data of samples with different formulations to obtain the corresponding storage modulus G' rheological curves, and evaluate the self-adhesion of the rubber compound according to the storage modulus.

2. The method for testing the self-adhesiveness of a rubber surface according to claim 1, characterized in that: In the step S1, the first scanning environment of the rubber processing analyzer is adjusted: the temperature detected by the rubber processing analyzer is 30-70° C., the scanning frequency is 0.1-5 Hz, and the strain value is 0.1-50%.

3. The method for testing the self-adhesiveness of a rubber surface according to claim 1, characterized in that: During the Delay process in S1, the prescribed time is 3 minutes to 5 minutes.

4. The method for testing the self-adhesiveness of a rubber surface according to claim 1, wherein: The multiple samples of different formula samples in S1 are one of different rubber samples, different gasket rubber formula samples, different airtight layer samples and different styrene-butadiene rubber formula samples.

5. The method for testing the self-adhesiveness of a rubber surface according to claim 4, characterized in that: The rubber sample is one of natural rubber, styrene-butadiene rubber, BR9000 butadiene rubber, high Mooney butadiene rubber and brominated butyl rubber.

6. The method for testing the self-adhesiveness of a rubber surface according to claim 4, characterized in that: The pad rubber formula samples mainly include natural rubber, carbon black, antioxidant and plasticizer, and the plasticizer in different pad rubber formula samples is one of C5 resin, 203 resin and 204 resin.

7. The method for testing the self-adhesiveness of a rubber surface according to claim 4, characterized in that: The different airtight layer samples are one of the airtight layer samples with different parking times, such as 0d, 1d, 2d and 5d.

8. The method for testing the self-adhesiveness of a rubber surface according to claim 4, characterized in that: The styrene-butadiene rubber formula sample can be used as a tread formula, and the styrene-butadiene rubber tread formula sample contains styrene-butadiene rubber and a plasticizer, and the plasticizer in different styrene-butadiene rubber tread formula samples is one of unoiled resin, paraffin oil and rosin resin.

9. The method for testing the self-adhesiveness of a rubber surface according to claim 1, characterized in that: In S2, the second scanning environment of the rubber processing analyzer is adjusted: the detection temperature of each sample with different formulations is lowered to 40° C., the scanning frequency is 1 Hz, and the strain value is 1-10%.

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