Method for determining life critical value of glass fiber base material adhesive tape and method for evaluating storage life of glass fiber base material adhesive tape

Abstract

The invention relates to a method for determining a life critical value of a glass fiber base material adhesive tape and a method for evaluating the storage life of the glass fiber base material adhesive tape. The determination method comprises the following steps: S11, arranging a thermal insulation material on the outer sides of a plurality of thermal vibration test tools, winding a glass fiber base material adhesive tape on the outer side of the thermal insulation material, and aging the glass fiber base material adhesive tape at the Tg temperature of the glass fiber base material adhesive tape; presetting a plurality of aging times; s12, at least one thermal vibration test tool is taken out for a thermal vibration test within a preset aging time, and whether the glass fiber base material adhesive tape falls off or fractures under a set thermal vibration condition or not is observed; if yes, the performance retention rate corresponding to the preset aging time is the adhesive tape life end value, and the difference value obtained by subtracting the adhesive tape life end value from the adhesive tape life critical value is 5%-10%; and if not, executing S12. The technical problem to be solved is how to quickly, effectively and reliably evaluate the long-term storage life of the glass fiber base material adhesive tape.

Description

Technical Field

[0001] The invention belongs to the research field of polymer material life, and particularly relates to a method for determining a critical value of the life of a glass fiber substrate adhesive tape and a method for evaluating the storage life. Background Art

[0002] At present, the research on the aging life of single silicone rubber products such as silicone rubber adhesives or silicone rubber seals when used in natural environments is generally carried out using accelerated life tests without changing the failure mechanism of the material, in order to accelerate the product failure process.

[0003] However, there are no reports on the aging life of composite silicone rubber products such as glass fiber substrate tapes used in specific high temperature and vibration environments. Glass fiber substrate tapes are used in high temperature and vibration environments, while single silicone rubber products are generally used as sealing rings or adhesives under static conditions; secondly, glass fiber substrate tapes are silicone rubber coated on glass fiber substrates, and the coated silicone rubber does not need to be vulcanized or cured to be used as a product, while single silicone rubber products need to be vulcanized, dried and cured before they can be made into test products; therefore, the accelerated life test used in the prior art to evaluate the aging life of silicone rubber cannot be applied to evaluate the aging life of glass fiber substrate tapes.

[0004] For specific aerospace engines, glass fiber substrate tape, as one of the key components of engine thermal insulation materials, faces the problem of life assessment in high temperature and vibration environments to ensure that it meets the overall use requirements and long-term storage requirements of the engine. Therefore, how to reasonably and reliably assess the long-term storage life of glass fiber substrate tape is a major issue that needs to be solved urgently. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for determining the critical value of the life of a glass fiber substrate tape and a method for evaluating the storage life. The technical problem to be solved is how to provide a method for determining the critical value of the life of a glass fiber substrate tape and a method for reasonably and reliably evaluating the long-term storage life of a glass fiber substrate tape. The method for determining the critical value of the life of a glass fiber substrate tape of the present invention utilizes reasonable condition simulation and performs performance failure verification based on tensile properties or shear properties to determine the critical value of the life, and provides a specific test plan for performance failure evaluation. The method for evaluating the storage life of a glass fiber substrate tape of the present invention can quickly, effectively and reliably evaluate the long-term storage life of a glass fiber substrate tape.

[0006] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. According to a method for determining the critical value of the life of a glass fiber substrate tape proposed by the present invention, the method comprises the following steps:

[0007] S11, place a heat insulating material on the outside of a plurality of thermal vibration test fixtures, wrap a glass fiber base tape around the outside of the heat insulating material, and place the glass fiber base tape at the T g Aging the glass fiber substrate tape at a temperature; presetting a certain aging time;

[0008] S12. Under a preset aging time, take out at least one thermal vibration test tool to perform a thermal vibration test to observe whether the glass fiber base tape falls off or breaks under the set thermal vibration conditions; if so, the performance retention rate corresponding to the preset aging time is the end-of-life value of the tape; the difference between the critical life value of the tape and the end-of-life value of the tape is 5% to 10%; if not, execute S12.

[0009] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0010] Preferably, in the aforementioned determination method, in step S12, at least three thermal vibration test fixtures are taken out to perform thermal vibration tests.

[0011] Preferably, in the aforementioned determination method, the time of the thermal vibration test is 15 to 85 minutes and the temperature is 1800 to 2200°C.

[0012] The purpose of the present invention and the technical problem solved by the present invention are also achieved by adopting the following technical solutions. According to the present invention, a method for evaluating the storage life of a glass fiber substrate tape comprises the following steps:

[0013] S41, obtaining a critical life value of the glass fiber substrate tape;

[0014] S42, selecting at least three temperature points to age a number of the glass fiber base tapes, wherein the temperature points are not higher than the Tg temperature of the glass fiber base tapes; obtaining the aging time at which the glass fiber base tapes reach the critical value of the life of the glass fiber base tapes at at least three temperature points; and establishing a relationship between the aging time and the aging temperature;

[0015] S43: evaluating the storage life of the glass fiber base material tape according to the ambient temperature of use or storage of the glass fiber base material tape.

[0016] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0017] Preferably, in the aforementioned evaluation method, in step S42, at least four temperature points are selected to age the glass fiber substrate tape.

[0018] Preferably, in the aforementioned evaluation method, in step S42, the temperature difference of the at least three temperature points is controlled within 80°C.

[0019] Preferably, in the aforementioned evaluation method, in step S42, when aging the glass fiber substrate tape at each of the temperature points, at least 10 aging times are set.

[0020] Preferably, in the aforementioned evaluation method, in step S42, at least 5 samples are taken out for each aging time to perform performance testing.

[0021] Preferably, in the aforementioned evaluation method, in step S42, the aging treatment is performed by hot air accelerated aging.

[0022] Preferably, in the aforementioned evaluation method, the storage life of the glass fiber base tape is evaluated by obtaining a curve of the natural logarithm of the aging time of the glass fiber base tape and the inverse of the aging temperature multiplied by 10000.

[0023] Preferably, the aforementioned evaluation method extrapolates the curve to estimate the storage life of the glass fiber substrate tape at a specified temperature.

[0024] By means of the above technical solution, the method for determining the critical value of the life of a glass fiber substrate tape and the method for evaluating the storage life of the glass fiber substrate tape of the present invention have at least the following advantages:

[0025] The method for determining the critical value of the life of a glass fiber substrate tape proposed by the present invention is to set a heat insulation material on the outside of several thermal vibration test fixtures, and wrap the glass fiber substrate tape on the outside of the thermal insulation material, which can simulate the working conditions of the glass fiber substrate tape fixing a specific engine thermal insulation material in a high temperature environment. Aging is performed at the Tg temperature without changing the failure mechanism, and the aged thermal vibration test fixture is subjected to a thermal vibration test simulating the working conditions of the engine to observe whether the glass fiber substrate tape falls off or breaks under the set thermal vibration conditions. If it falls off or breaks, it can be determined that the performance of the tape has failed, that is, the end value of the life of the tape is obtained, and the performance retention rate of 5% to 10% greater than the end value of the life of the tape is determined as the critical value of the life of the tape; if it does not fall off or break, it is necessary to continue to further age the remaining fixtures, and then determine the critical value of the life after the thermal vibration test. The method is simple, highly operable, and can simulate the critical value of the life of the glass fiber substrate tape working in a specific high temperature and vibration environment through aging treatment and thermal vibration test, and the determined critical value of the life is reliable and reasonable.

[0026] The storage life evaluation method of the glass fiber substrate tape proposed in the present invention is based on the critical life value of the glass fiber substrate tape, designs a thermal aging treatment program, optimizes the result data of the sample performance measurement, and finally performs corresponding life evaluation through the Arrhenius formula. The method can quickly, effectively and reliably evaluate the aging life of the glass fiber substrate tape in long-term storage in a natural environment.

[0027] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 3 is a curve showing the relationship between the shear performance retention rate and the aging time at different aging temperatures in Example 1 of the present invention.

[0029] Figure 2 It is a graph of the natural logarithm of the aging time and the inverse of the aging temperature multiplied by 10,000. DETAILED DESCRIPTION

[0030] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the specific implementation method, structure, characteristics and effects of the method for determining the critical value of the life of the glass fiber substrate tape and the method for evaluating the storage life proposed by the present invention in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0031] The first aspect of the present invention provides a method for determining a critical value of the life of a glass fiber substrate tape, which comprises the following steps:

[0032] (1) A heat insulating material is placed outside of a plurality of thermal vibration test fixtures, and a glass fiber base tape is wrapped around the outside of the heat insulating material. g Aging the glass fiber substrate tape at a temperature; presetting a certain aging time;

[0033] (2) At a preset aging time, take out at least one thermal vibration test fixture for thermal vibration test, preferably, take out at least three thermal vibration test fixtures for thermal vibration test, the thermal vibration test time is 15 to 85 minutes, and the temperature is 1800 to 2200°C; observe whether the glass fiber substrate tape falls off or breaks under the set thermal vibration conditions; if so, the performance retention rate corresponding to the preset aging time is the end-of-life value of the tape; the difference between the critical life value of the tape and the end-of-life value of the tape is 5% to 10%; if not, execute step (2).

[0034] In the present invention, if the glass fiber base tape does not break or fall off after the thermal vibration test of the thermal vibration test tooling is completed at the preset aging time, it can be determined that the glass fiber base tape at the performance retention rate corresponding to the preset aging time still meets the application requirements. It is necessary to continue to further age the remaining tooling and then conduct thermal vibration tests until the glass fiber base tape breaks or falls off after the thermal vibration test, then it can be determined that the tape performance has failed, that is, the end-of-life value of the tape is obtained, and a performance retention rate of 5% to 10% greater than the end-of-life value of the tape is selected as the critical value of the tape life.

[0035] In the present invention, the performance retention rate of the glass fiber base tape is the retention rate of tape properties such as shear strength, tensile strength, and elastic modulus.

[0036] A second aspect of the present invention provides a method for evaluating the storage life of a glass fiber substrate tape, comprising the following steps:

[0037] First, the critical life value of the glass fiber substrate tape is obtained. The critical performance failure value determines whether the residual performance of the material still meets the use requirements after long-term storage and aging. Therefore, the present invention first determines the critical life value of the glass fiber substrate tape, and then evaluates the storage life of the glass fiber substrate tape based on the critical life value.

[0038] Secondly, at least three temperature points are selected to age a number of the glass fiber substrate tapes, and the temperature points are not higher than the Tg temperature of the glass fiber substrate tape; the aging time of the glass fiber substrate tape to reach the critical value of the life of the glass fiber substrate tape at at least three temperature points is obtained; and the relationship between the aging time and the aging temperature is established. The selection of at least three temperature points that are not higher than the Tg temperature of the glass fiber substrate tape is to ensure that the aging reaction and aging mechanism of the glass fiber substrate tape at different temperatures are the same, thereby ensuring the accuracy and reliability of the aging time data at different aging temperatures. Furthermore, in order to meet the conditions for the subsequent data to be processed by the Arrhenius formula, the selected minimum temperature should make the time required to reach the critical value of the life not less than 1000 hours.

[0039] In the present invention, at least 4 temperature points are selected to age the glass fiber substrate tapes. Thus, it is possible to ensure that the aging reactions of the glass fiber substrate tapes at different aging temperatures are the same, and in order to reduce the test error, the temperature intervals of the at least 4 temperature points should be similar. Furthermore, the temperature difference of the at least 3 temperature points or at least 4 temperature points described in the present invention is controlled within 80°C, which is more conducive to ensuring that the aging reactions of the glass fiber substrate tapes at different aging temperatures are the same and reducing the test error.

[0040] In the present invention, when the glass fiber substrate tape is aged at each temperature point, at least 10 aging times are set, for example, 10 aging times, 11 aging times, 12 aging times, etc. According to the thermal accelerated aging rate at different temperatures, a high aging temperature can quickly reach the critical performance value, while a lower temperature requires a longer time. Therefore, the present invention sets at least 10 aging times to ensure that the glass fiber substrate tape can continue to be aged and sampled for testing until it reaches the critical life value after completing all the set aging cycles and still does not exceed the critical life value.

[0041] In the present invention, at least 5 samples are taken out for performance testing at each aging time, thereby discarding individual samples with large test errors, and accurate data can still be obtained based on the remaining samples, thereby ensuring the accuracy and reliability of the data.

[0042] In the present invention, the aging treatment is carried out by hot air accelerated aging. The specific steps of hot air accelerated aging treatment are as follows:

[0043] (1) Determine the aging environment.

[0044] The aging temperature needs to be selected at least 3 temperature points, and in order to ensure that the aging reaction of the glass fiber base tape at different temperatures is the same and to reduce the test error, it should be carried out within a similar temperature range.

[0045] (2) Determine the sampling period.

[0046] The sampling period is mainly determined by the thermal accelerated aging rate at different temperatures. A high aging temperature can quickly reach the performance critical value, while a lower temperature requires a longer time. In the present invention, the sampling period is set to 0h, 10h, 20h, 50h, 100h, 200h, 400h, 600h, 1000h, 1500h, 2000h, 3000h, etc.

[0047] (3) Confirmation and preparation of sample quantity.

[0048] In the present invention, in order to ensure the accuracy of each group of performance tests, at least 5 samples should be taken out for testing at each time point of aging at each temperature. At the same time, the number of samples is also related to the set time point, the number of aging temperatures, and the number of sample performances to be tested.

[0049] The specimens were prepared according to the shear performance test standard GB / T 33332-2016 “Test method for dynamic shear strength of adhesive tapes”.

[0050] (4) Conduct hot air accelerated aging test.

[0051] The test sample is placed in a hot air accelerated aging test chamber for aging. During the test, air circulation in the test chamber should be ensured to ensure that the heating aging rate is not affected by accumulated substances, volatile substances or oxygen loss.

[0052] According to the present invention, the sample to be tested is taken out at the corresponding sampling node. The sample to be tested is placed at room temperature for 30 to 50 minutes, and the shear strength test is performed after cooling. The shear strength test is performed according to the standard GB / T33332-2016 "Test method for dynamic shear strength of adhesive tape".

[0053] According to the present invention, at an aging temperature, if the sample has not exceeded the critical life value after completing all set aging cycles, the aging treatment is continued and sampling is carried out (the sample is sufficient); if the test result reaches the critical life value ahead of schedule, the aging test can also be terminated ahead of schedule.

[0054] Finally, the storage life of the glass fiber base material tape is evaluated according to the ambient temperature in which the glass fiber base material tape is used or stored.

[0055] In the present invention, the method for evaluating the storage life of the glass fiber substrate tape is to obtain a curve of the natural logarithm value of the aging time of the glass fiber substrate tape and the inverse of the aging temperature multiplied by 10000. Therefore, a graph is drawn with the natural logarithm value of the time at which each aging temperature reaches a critical value corresponding to the inverse of the corresponding aging temperature multiplied by 10000, and by plotting each point and obtaining the best fitting straight line, a curve of the natural logarithm value of the aging time of the glass fiber substrate tape and the inverse of the aging temperature multiplied by 10000 is obtained. The curve meets the conditions for estimating the life by using the Arrhenius plot, indicating that the method for evaluating the storage life of the glass fiber substrate tape is feasible and reliable.

[0056] In the present invention, the curve is extrapolated to estimate the storage life of the glass fiber base tape at a specified temperature. Thus, by extrapolating the curve of the natural logarithm of the aging time and the inverse of the aging temperature multiplied by 10,000, the long-term storage life of the glass fiber base tape at a specified temperature, such as 25°C, 28°C, 30°C, etc., can be obtained.

[0057] According to the present invention, the method for evaluating the storage life of the glass fiber substrate tape is carried out in accordance with GB / T20028-2005 "Estimation of the life and maximum operating temperature of vulcanized rubber or thermoplastic rubber using Arrhenius diagram".

[0058] The Arrhenius formula is expressed as formula 1:

[0059] K=A0e -E / RT (1)

[0060] Where: K is the aging rate constant; T is the temperature (K); A0 is the kinetic parameter; E is the activation energy (J / mol); R is the gas constant (J / (mol·K)).

[0061] The chemical reaction relationship is expressed as formula (2):

[0062] P x (t) = K(t)·t (2)

[0063] Where P x (t)—function of reaction relationship; K(t)—aging rate constant; t—reaction time (h).

[0064] At different reaction temperatures T i Under different reaction rates K i Reaching the same critical value P with different reaction times a , that is:

[0065] P a (t i )=K i (t i )·t i (3)

[0066] Combining the Arrhenius formula with the chemical reaction relationship, that is, substituting equation (1) into equation (3), it is expressed as equation (4):

[0067] P a (t i )=A0e -E / RT ·t i (4)

[0068] By taking ln from both sides of equation (4) and combining the constant term, we can get the relationship between the critical aging time of life and the aging temperature, which is expressed as equation (5).

[0069] lnt i =E / RT i +B (5)

[0070] In the range of similar aging temperatures, it can be considered that the reaction activation energy E is the same. Therefore, from formula (5), it can be seen that the aging temperature T and the aging degree P a The ln value of the time required is proportional to the ln value of the time required. Therefore, in order to easily obtain the time required for the sample to reach the critical value of performance under various temperature conditions, the selected performance test value is plotted as a function of time, and the time t1, t2, t3, etc. required to reach the critical value of performance are obtained by the insertion method. The logarithm lnt of the time required for each test temperature to reach the critical value is plotted against the inverse of the thermodynamic temperature of the corresponding test temperature 10000 / T. By plotting each point and obtaining the best fitting straight line, the Arrhenius diagram representing the critical value time-aging temperature relationship can be obtained. The life can be extrapolated by the obtained straight line to obtain the estimated storage life at the specified temperature.

[0071] The present invention will be further described below in conjunction with specific embodiments, but this should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0072] Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, the technical terms or scientific terms used should have the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0073] Example 1

[0074] (1) Confirmation of life assessment basis

[0075] In this embodiment, the performance to be tested is shear strength, and the performance test process is carried out according to the corresponding national standard GB / T 33332-2016 "Test method for dynamic shear strength of adhesive tape".

[0076] (2) Confirmation of critical life value

[0077] The Tg of the tape was obtained by TG thermogravimetric analysis to be 190°C; the tape was aged at 190°C, and samples were taken at 0h, 10h, 20h, 50h, 100h, 200h, 400h, 600h, 1000h, and 1500h for shear performance testing. Based on the test results, an aging time-shear performance retention rate curve at a temperature of 190°C was established. From the curve, it can be obtained that the shear strength retention rate is 70% at 512h, 60% at 886h, and 50% at 1256h.

[0078] ① Prepare three engine simulation parts as thermal vibration test fixtures, insulate them with alumina fiber composite materials, and then use glass fiber base tape to wrap and fix the insulation material.

[0079] ② After the glass fiber base tape is wound, the three simulated parts are placed in a high-temperature aging box and aged at 190°C. They are taken out when the aging time reaches 512h, 886h, and 1256h, respectively. After cooling to room temperature, a thermal vibration test is carried out. The temperature of the thermal vibration test is set to 1800°C, the time is 85min, and the frequency is 200Hz. The status of the glass fiber base tape in the three simulated parts is monitored.

[0080] Since the engine simulation part is insulated with ultra-high temperature / high temperature composite insulation materials, the temperature when the heat is transferred to the glass fiber base tape is lower than 400°C, which meets the operating temperature of the glass fiber base tape.

[0081] For the simulated parts with an aging time of 512h and a shear strength retention rate of 70%, it was observed that the glass fiber base tape did not fall off during the thermal vibration test. It was determined that the glass fiber base tape with a shear strength retention rate of 70% still met the application requirements.

[0082] For the simulated parts with an aging time of 886h and a shear strength retention rate of 60%, it was observed that the glass fiber base tape did not fall off during the thermal vibration test. It was determined that the glass fiber base tape with a shear strength retention rate of 60% still met the application requirements.

[0083] For the simulated parts with an aging time of 1256h and a shear strength retention rate of 50%, it was observed that the glass fiber base tape fell off during the thermal vibration test. It was determined that the glass fiber base tape with a shear performance retention rate of 50% could not meet the application requirements, and its life was therefore determined to have come to an end.

[0084] In summary, the service life ends when the shear performance retention rate reaches 50%, while it still meets the actual application requirements when it reaches 60%. Therefore, in this embodiment, the shear performance retention rate of 60% is taken as the critical value of the service life.

[0085] (3) Aging treatment

[0086] This step is the accelerated aging treatment stage of the glass fiber substrate tape. The specific steps are as follows:

[0087] ○1) Determine the aging environment

[0088] The aging temperature is selected at 130℃, 140℃, 150℃, and 160℃.

[0089] During the test, air circulation in the test chamber is ensured to ensure that the heating aging rate is not affected by accumulated substances or volatile substances or oxygen loss.

[0090] ②Determine the sampling period

[0091] In this embodiment, the sampling periods are set to 0h, 10h, 20h, 50h, 100h, 200h, 400h, 600h, 1000h, 1500h, 2000h, and 3000h.

[0092] ③Confirmation and preparation of sample quantity

[0093] In this embodiment, 7 samples are prepared at each time node of temperature aging, 12 sampling time nodes, and 4 aging cycles, and a total of 336 samples are actually required.

[0094] Since the aging test cycle is long and the repetitive cost is too high, in order to ensure the sufficiency of samples or the abandonment of individual samples due to large test errors, a total of 400 samples are prepared in this embodiment.

[0095] The sample is prepared according to the requirements of the above-mentioned shear performance test standard. The specific sample preparation steps are as follows:

[0096] Cut the middle part of each roll of glass fiber substrate tape as the test tape, place two stainless steel plates flat on a horizontal table, connect one end of the two stainless steel plates, and use the glass fiber substrate tape to stick the two stainless steel plates together in a direction perpendicular to the joint of the two stainless steel plates, and use the tape to wrap around one circle; along the direction of the joint of the two stainless steel plates, the tape is only bonded to the middle of the stainless steel, and the stainless steel near the two ends is exposed; the area of ​​the stainless steel covered by the tape accounts for 37.5% of its total area. Without applying pressure, use the mass of the roller (cylindrical steel roller, diameter (85±2.5) mm, width (45±1.5) mm, surface coated with about 6 mm thick rubber, Shore A hardness (80±5), no convex and concave deviation, the mass of the roller should be (2000±100) g) to roll the tape sample evenly, and roll it back and forth twice along the length of the tape, the rolling speed is 10 mm / s, and no additional pressure can be applied.

[0097] ④ Take out the test samples at the corresponding time point, place them at room temperature for 30 minutes, and conduct shear strength test after cooling.

[0098] According to the shear performance test results of each sample at different aging treatment times, the corresponding shear performance retention rate under each condition is calculated, such as Figure 1 As shown in Figure 2, the relationship between the shear performance retention rate and the aging treatment time under different aging temperature conditions. Figure 1As shown, when the shear performance retention rate P is 60%, the aging time required at 130°C is 3680h, the aging time required at 140°C is 2501h, the aging time required at 150°C is 1729h, and the aging time required at 160°C is 1177h.

[0099] (4) Derivation of the Arrhenius formula

[0100] This is done in accordance with GB / T 20028-2005 “Estimation of service life and maximum operating temperature of vulcanized rubber or thermoplastic rubber using Arrhenius diagram”.

[0101] According to the above step (2), the shear performance critical value is selected as 60%, that is, the performance retention rate P in the Arrhenius formula is 60%.

[0102] According to the formula lnti=E / RTi+B, a functional relationship curve of the ln value of the aging time (lnt) and the inverse of the aging temperature (10000 / T) is made, and through linear fitting processing, the following is finally obtained: Figure 2 The relationship between lnt and 10000 / T is shown in the figure. Finally, according to the extrapolation method, the lnt value at room temperature 30°C is 13.6374, and the calculated t value is 836850h, which is converted into 95.5 years. The safety factor is 2, that is, the long-term storage life of the glass fiber substrate tape at room temperature (30°C) is 47.8 years.

[0103] Example 2

[0104] The process flow of Example 2 is the same as that of Example 1, except that:

[0105] 1. In step (2), the temperature of the thermal vibration test is set to 2200° C., the time is 15 min, and the frequency is 210 Hz. The shear performance retention rate is 64.6%, which is used as the critical life value.

[0106] 2. In step (3), the aging temperature is selected from 140°C, 150°C, 160°C, and 170°C.

[0107] 3. In step (4), the performance retention rate P in the Arrhenius formula is 64.6%, and the long-term storage life of the glass fiber substrate tape at room temperature (30° C.) is 42.3 years.

[0108] Example 3

[0109] The process flow of Example 3 is the same as that of Example 1, except that in step (1), tensile strength is used as the life detection performance index. The sample is prepared according to the requirements of the tensile strength test standard GB / T 30776-2014 "Test method for tensile strength and elongation at break of adhesive tape", and the tensile strength life critical value is finally obtained to be 50%, and the long-term storage life of the glass fiber substrate tape at room temperature (30°C) is finally obtained to be 60 years. The tensile strength is used as the life detection performance index, and the performance test process is carried out according to the corresponding national standard GB / T 30776-2014 "Test method for tensile strength and elongation at break of adhesive tape".

[0110] According to the embodiments of the present invention, Example 1 uses the shear strength retention rate as the life evaluation index, and the storage life of the glass fiber base tape obtained is 47.8 years; Example 2 uses the shear strength retention rate as the life evaluation index, and the storage life of the glass fiber base tape obtained is 42.3 years; and Example 3 uses the tensile strength retention rate as the life evaluation index, and the storage life of the glass fiber base tape obtained is 60 years.

[0111] Since the accuracy of the storage life of the glass fiber base tape evaluated by the present invention at room temperature (30°C) is inaccurate compared with the storage life of the glass fiber base tape stored for a long time in a natural environment, based on the importance of the glass fiber base tape of the present invention in the engineering field and higher product quality requirements, the present invention determines that the shear strength retention rate is used as the life evaluation index, and the safety factor is taken as 2, so that the storage life of the glass fiber base tape obtained has higher reliability, effectiveness and safety.

[0112] In the present invention, the evaluation method of the storage life of the glass fiber substrate tape adopts the tape performance retention rate as the evaluation index of the critical value of the tape life, and the performance retention rate is the performance retention rate of the tape performance such as shear strength, tensile strength, elastic modulus, etc. Since the technicians in this field cannot predict in advance which performance of the specific different types of glass fiber substrate tapes will fail first during the initial test, it is necessary to test multiple performances (shear strength, tensile strength, elastic modulus, etc.) of a specific tape during the initial test, and finally select the performance with the shortest aging life as the final evaluation index.

[0113] The technical features in the claims and / or the specification of the present invention may be combined, and the combination is not limited to the combination obtained by reference in the claims. The technical solution obtained by combining the technical features in the claims and / or the specification is also within the protection scope of the present invention.

[0114] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for determining the critical value of the life of a glass fiber substrate tape, characterized in that: It includes the following steps: S11, place a heat insulating material on the outside of a plurality of thermal vibration test fixtures, wrap a glass fiber base tape around the outside of the heat insulating material, and place the glass fiber base tape at the T g Aging the glass fiber substrate tape at a temperature; presetting a certain aging time; S12. Under a preset aging time, take out at least one thermal vibration test tool to perform a thermal vibration test to observe whether the glass fiber base tape falls off or breaks under the set thermal vibration conditions; if so, the performance retention rate corresponding to the preset aging time is the end-of-life value of the tape; the difference between the critical life value of the tape and the end-of-life value of the tape is 5% to 10%; if not, execute S12.

2. The method according to claim 1, characterized in that In step S12, at least three thermal vibration test fixtures are taken out to perform thermal vibration tests.

3. The method according to claim 1 or 2, characterized in that: The time of the thermal vibration test is 15 to 85 minutes; the thermal vibration temperature is 1800 to 2200°C.

4. A method for evaluating the storage life of a glass fiber substrate tape, characterized in that: It includes the following steps: S41, obtaining a critical life value of the glass fiber substrate tape; S42, selecting at least three temperature points to age a number of the glass fiber base tapes, wherein the temperature points are not higher than the Tg temperature of the glass fiber base tapes; obtaining the aging time at which the glass fiber base tapes reach the critical value of the life of the glass fiber base tapes at at least three temperature points; and establishing a relationship between the aging time and the aging temperature; S43: evaluating the storage life of the glass fiber base material tape according to the ambient temperature of use or storage of the glass fiber base material tape.

5. The method according to claim 4, characterized in that In step S42, at least four temperature points are selected to age the glass fiber substrate tape; In step S42, the temperature difference of the at least three temperature points is controlled within 80°C.

6. The method according to claim 4 or 5, characterized in that: In step S42, when aging the glass fiber base tape at each temperature point, at least 10 aging times are set.

7. The method according to claim 5, characterized in that In step S42, at least 5 samples are taken out for performance testing at each aging time.

8. The method according to claim 4, characterized in that In step S42, the aging treatment is performed by hot air accelerated aging.

9. The method according to claim 4, characterized in that The method for evaluating the storage life of the glass fiber base tape is to obtain a curve of the natural logarithm of the aging time of the glass fiber base tape and the inverse of the aging temperature multiplied by 10000.

10. The method according to claim 9, characterized in that The curve is extrapolated to estimate the storage life of the glass fiber substrate tape at a specified temperature.

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