GB/T 1681-2009 English PDFUS$274.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 1681-2009: Rubber -- Determination of rebound resilience of vulcanizates Status: Valid GB/T 1681: Historical versions
Basic dataStandard ID: GB/T 1681-2009 (GB/T1681-2009)Description (Translated English): Rubber -- Determination of rebound resilience of vulcanizates Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: G40 Classification of International Standard: 83.060 Word Count Estimation: 14,159 Date of Issue: 2009-04-24 Date of Implementation: 2009-12-01 Older Standard (superseded by this standard): GB/T 1681-1991 Adopted Standard: ISO 4662-1986, IDT Regulation (derived from): National Standard Approval Announcement 2009 No.6 (Total No.146) Issuing agency(ies): General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China Summary: This standard specifies the method to measuring the impact of fashion rubber elasticity. This standard applies at the test temperature hardness of vulcanized rubber 30IRHD to 85IRHD between. GB/T 1681-2009: Rubber -- Determination of rebound resilience of vulcanizates---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.Rubber - Determination of rebound resilience of vulcanizates ICS 83.060 G40 National Standards of People's Republic of China Replace GB/T 1681-1991 Determination of vulcanized rubber resilience (ISO 4662.1986, IDT) Released on.2009-04-24 2009-12-01 implementation General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China China National Standardization Administration issued ForewordThis standard is equivalent to ISO 4662.1986 "Determining the Resilience of Vulcanized Rubber" (English version). This standard replaces GB/T 1681-1991 "Determination of vulcanized rubber resilience". This standard is equivalent to translation ISO 4662.1986. For ease of use, this standard makes the following editorial changes. a) replace “this International Standard” with “this standard”; b) replace the "," as a decimal point with a decimal point "."; c) The preamble to international standards has been removed. The main changes in this standard compared with GB/T 1681-1991 are as follows. --- Added introduction; --- Added security warning terms; --- Added "terms and definitions" section (Chapter 3 of this edition); --- A more detailed description and regulation of the test instrument and calibration (Chapter 4 of this edition); --- Added informative Appendix A and Appendix B. Appendix A and Appendix B of this standard are informative annexes. This standard was proposed by the China Petroleum and Chemical Industry Association. This standard is under the jurisdiction of the National Rubber Standards Committee for Rubber Physics and Chemical Testing Methods Standardization Sub-Committee (SAC/TC35/SC2). This standard is mainly drafted by. Tianjin Rubber Industry Research Institute. Participated in the drafting of this standard. Guizhou Tire Co., Ltd. The main drafters of this standard. Du Ming, Li Zi'an, Chen Jing. Participated in the drafting of this standard. Feng Ping. The previous versions of the standards replaced by this standard are. ---GB/T 1681-1982, GB/T 1681-1991.IntroductionWhen the rubber is deformed, it is accompanied by the input of energy. When the rubber returns to its original shape, a portion of this energy is released, leaving The part is converted into thermal energy from the mechanical energy inside the rubber. When the deformation is a depression due to a single impact, the ratio of the output energy to the input energy is defined as the resilience. For the same substance, the value of the resilience is not a fixed amount, it is the temperature distribution, the strain distribution (by the type and size of the punch and the sample) The inch rate), the strain rate (determined by the rate of the punch), the strain energy (determined by the rate and quality of the punch) and the change in the strain process. The strain process is particularly important where the polymer is present in the filler. The stress softening effect in the polymer should also be mechanically adjusted. The change in resilience with conditions is a property of the polymer. If the test is carried out under a wide range of conditions, only the polymer can be estimated. Resilience. The effects of these factors described above on resilience are different and occur near the temperature region where the material changes. Testing is the main factor affecting resilience. Factors related to time and sag amplitude also have a certain influence, and will produce large deviations. In order to obtain the ideal resilience data, the specimen should be bonded to the rigid support to avoid the slippage caused during the impact. Friction loss. Since in many cases it is not practical to take a method of bonding the specimen, it is necessary to firmly hold the specimen to avoid frictional slippage. In actual equipment operation, in order to approach these ideal conditions, some restrictions on the hardness of the sample (see GB/T 6031) are ten. Subsequent. Test the sample with high hardness to ensure the rigidity of the instrument meets the requirements, and test the sample with low hardness to ensure the clamping of the sample. If the selected mechanical conditions and the appropriate instrument are selected, standard resilience data with satisfactory reproducibility can be obtained at any temperature. Determination of vulcanized rubber resilience Warning. Personnel using this standard should have practical experience in formal laboratory work. This standard does not address all possible security issues. It is the responsibility of the user to take appropriate safety and health measures and to ensure compliance with the conditions set by the relevant national regulations.1 ScopeThis standard specifies the method for determining the rubber resilience by impact in a small range of impact strain and strain rate. This standard applies to vulcanized rubber with a hardness between 30 IRHD and 85 IRHD at the test temperature.2 Normative referencesThe terms in the following documents become the terms of this standard by reference to this standard. All dated references, followed by all Modifications (not including errata content) or revisions do not apply to this standard, however, parties to agreements based on this standard are encouraged to study Is it possible to use the latest version of these files? For undated references, the latest edition applies to this standard. GB/T 2941 Rubber physical test method General procedure for preparation and adjustment of specimens (GB/T 2941-2006, ISO 23529.2004, IDT) GB/T 6031 Determination of hardness of vulcanized rubber or thermoplastic rubber (10 to 100 IRHD) (GB/T 6031-1998, idt ISO 48.1994) Rubber and rubber products -- Determination of dynamic properties -- Part 1 . General rules (GB/T 9870.1-2006, ISO 4664-1.2005, IDT)3 Terms and definitionsThe following terms and definitions established in GB/T 9870.1 apply to this standard. 3.1 The ratio of the energy output to the energy input when impacting a flat, freely convex sample with a spherical object. The quality of the impacted object, the characteristics of the punch and the sample to be impacted shall be within the following specified ranges. Note 2. The above basic characteristics (12.5mm, 12.5mm, 0.35kg, 1.4m/s, 351kJ/m3) are the same as the Luke pendulum, and the tolerances can be included in the correction. Cobb pendulum (15.0mm; 12.5mm; 0.25kg; 2m/s; 427kJ/m3) tolerance range. In addition, the following tolerances are allowed. --- Considering the steel balls and machining tolerances with nominal diameters of 12.5mm and 15mm, a small tolerance (±0.05mm) is used.4 instruments4.1 Overview The test instrument consists of a pendulum-like, single-degree-of-freedom mechanical oscillating device and a sample holder. The two parts are assembled together in an appropriate manner to measure the resilience, and each part can be adjusted or adjusted for the swinging device. Remove it. It shall also be configured to measure the height of the pendulum rebound, either as a calibrated scale or as an electrical signal. Practical instruments of all designs that meet the above requirements can be used (see Appendix B). Note. All instruments should be designed to operate within the limits specified by various parameters and accurately calibrated to give substantially the same resilience value. 4.2 Swing device The oscillating device is composed of a pendulum rod and a hemispherical pendulum. The pendulum can move along an arc track under the action of gravity, or it can be spring or twisted. The linear motion of the rotating wire under the action of the restoring force. At the impact point, the spherical punch speed is horizontal, that is, the contact direction of the punch with the sample. Should be perpendicular to the specimen. 4.2.1 Scale (see Figure 1) a) uniform scale b) Square scale (according to the law 槡R) c) Nonlinear square scale [in accordance with the law 3πarccos (1-0.5R)] Figure 1 Scale example For the pendulum of the resilience generated by gravity, the resilience R is calculated by. In the formula. H---landing height. It is convenient to measure the horizontal rebound distance and the rebound angle with a scale, especially for rigid pendulum. For a resilience pendulum produced by the force of a twisted wire or spring, the resilience R is calculated by. For this type of instrument, it is convenient to measure the angle of the rebound with a scale. The resilience can be measured using a scale with a uniform scale or a direct reading, such as using a uniform scale to measure resilience, and should be replaced with Calculate transformation equations, charts, and tables. 4.2.2 Adjustment of the swinging device The complete instrument shall be subjected to repeated operation of the impact rubber specimen within the specified hardness range, and the impact motion shall be smooth and shall not be shaken or vibrated. The cause of the jitter or vibration is due to the poor rigidity of the rigid body part or the defect of the guiding system. For initial commissioning or periodic inspection, the specimen holder shall be removed from the swinging device and operated as follows. 4.2.2.1 For the calculation of the inertia parameter, the mass of the pendulum shall be directly referred to and its geometry and its distance to the guide shaft shall be measured. From It is possible to determine the equivalent impact mass consistent with the provisions of Chapter 3 and the impact stroke without significant reaction force to the guide shaft or the hanger shaft. Make sure that the diameter of the punch meets the requirements of Chapter 3, and in any case, the spherical surface of the punch should exceed the depth of the depression of the rubber. The head is preferably a complete hemisphere. 4.2.2.2 The entire oscillating device shall be freely located at the equilibrium position, ie the zero position of the scale. This point shall also be the point at which the impact occurs, the spherical punch The movement at this point should be horizontal. 4.2.2.3 In order to correct the friction loss, the swinging device should be adjusted during the swinging process. Timing the swing period, then recording the one-way swing frequency. For small nonlinear swings, the correction of the scale is irrelevant for the current use (see 4.2.2.5). If the operation of the instrument involves different damping conditions during the measurement process, such as the damping generated by connecting the pointer jaws, Line measurements are taken and averaged. 4.2.2.4 For the following different swings, the average of the five swings shall be taken to calculate the full period (T) and the logarithmic decay rate (Λ) 4.2.2.5 The deviation of any one of T1, T2 and T4 from its average value should not exceed 10%, and the deviation can be less than 1%. Ignore, when the deviation is between 1% and 10%, the appropriate nonlinear correction of the scale should be considered. Pendulum energy should be applied at the corresponding scale point As a basis for correction. The impact velocity should be verified based on the geometry and the average of T1, T2 and T4, or the mass and energy of a single rebound. Impact speed Should comply with the provisions of Chapter 3. 4.2.2.6 The deviation of any one of Λ1, Λ2 and Λ4 from its mean value shall not exceed 0.01 and no value shall be More than 0.03. When the value is less than 0.01, it can be ignored. When the value is between 0.01 and 0.03, the correction value of the rebound result should be provided. This correction should have a depreciation value, and the best way is to obtain the desired value for a single impact by moving the starting point of the pendulum. GB/T 1681-2009/ISO 4662.1986 In most cases, calibration calculations may not be performed. For more accurate analysis, the above calculations may be used for correction. 4.3 Sample fixture 4.3.1 During the mechanical adjustment and resilience measurement, the circular specimen shall be firmly fixed. The specimen shall be placed against a flat, smooth sample stage and shall be perpendicular and orthogonal to the direction of the impact velocity. The sample stage is part of the base. If the stand is independent, it should have a mass of at least.200 times the impact mass. otherwise It should be fixed on a very stable system. For example. stone masonry structure. Any suitable clamping device can be used as long as the measured resilience data is the same as the value obtained from the sample stuck to the rigid plate. The difference is not more than 0.02 (absolute rebound value). It can be tested with high elasticity (about 0.90) and high hardness (about 85IRHD). Is it appropriate? Suitable clamping devices include vacuum clamps, mechanical clamps, and vacuum-mechanical integrated clamps. A mechanical fixture device recommended by this standard, It consists of a metal ring (see Figure 2). This metal ring has an inner diameter of 20 mm and an outer diameter of 35 mm and is applied to the front side of the specimen by means of a spring. (200 ± 20) N force. In the rest position, the punch should be at the center of the retaining ring. Another method for holding specimens recommended by this standard The sample is sucked by vacuuming the back side of the sample. This can be done by creating a suction force from an annular groove having a diameter of 25 mm and a width of 2 mm. The pump used should be kept at an absolute pressure not exceeding 10 kPa. In this case, the force applied to the retaining ring can be reduced to (150 ± 15) N. The side of the fixture should not be pressed against the specimen, at least 2mm clearance should be left around the specimen so that the specimen can be freely free from impact. Raised. 4.3.2 If the measurement is carried out under a series of conditions different from room temperature, the pendulum instrument shall be placed in accordance with the requirements of GB/T 2941. Operate in a suitable incubator or cooling chamber. In this case, the instrument should be calibrated within the test temperature range (see 4.2.2). In addition, it can be taken Take appropriate measures to heat or cool the specimen holder with the circulating liquid (see Figure 3). In order to ensure that the sample is completely controlled by the temperature medium package It is best to add a cooled or heated air curtain to the front of the fixture. Thermocouple or other measurement when measuring with a thermocouple or other method The meter should be placed as close as possible to the specimen to accurately measure the fixture temperature.5 sample5.1 Preparation The sample shall be prepared in accordance with the method of GB/T 2941, and may be molded or die cut. There should be no fiber or reinforced matrix material in the sample. The surface of the sample shall be smooth, smooth and parallel to the upper and lower surfaces, and may be ground if necessary. If the impacted surface is sticky, it can be sprinkled on it. Some insulating materials, such as talc, can be avoided. 5.2 size The standard sample thickness shall be 12.5 mm ± 0.5 mm and a disc having a diameter of 29 mm ± 0.5 mm. Method for measuring non-standard samples See Appendix A. 5.3 Dimensional measurement The thickness of the specimen shall be measured to the nearest 0.05 mm and the diameter shall be measured to the nearest 0.2 mm. 5.4 Number of samples Two samples should be measured continuously for each material. 5.5 Adjustment 5.5.1 The time interval between vulcanization and testing shall be in accordance with GB/T 2941. 5.5.2 Light exposure should be avoided as completely as possible during the interval between vulcanization and testing. 5.5.3 If the specimen is sanded, the time interval between sanding and testing shall not exceed 72 h. GB/T 1681-2009/ISO 4662.1986 5.5.4 Prepared samples shall be adjusted at the standard laboratory temperature specified in GB/T 2941 prior to direct testing.6 test temperatureThe standard laboratory temperature (see 5.5.4) is preferred, and the test can also be carried out at one or more of the following temperatures. -75 °C, -55 ° C, -40 ° C, -25 ° C, -10 ° C, 0 ° C, 40 ° C, 55 ° C, 70 ° C, 85 ° C, 100 ° C. The temperature deviation should not exceed ±1 °C. Other temperatures can be used at other intervals as the resilience changes rapidly with temperature.7 test steps7.1 Temperature adjustment If the test temperature is different from the standard laboratory temperature (see 5.5.4), the entire set of test equipment should either be heated or The special fixture for cooling (see 4.3.2) is adjusted to the test temperature. Install the specimen on the fixture and adjust for sufficient time to reach the temperature within the required tolerances. Alternatively, it can be removed from the fixture The samples are respectively heated or cooled in an incubator or cooling chamber in accordance with GB/T 2941. Then quickly insert the sample into the heating Or after cooling the fixture. In this case, the adjustment time on the fixture was reduced to 3 min before the test. In the low temperature test, a device to prevent frosting of the sample should also be installed. 7.2 Mechanical adjustment of the sample After the specified temperature adjustment and the installation of the appropriate fixture device, the sample can be tested no less than three times and not more than seven times. Continuous impact as a mechanical adjustment. 7.3 Resilience measurement Immediately after the mechanical adjustment, the specimen was subjected to three impacts at the same speed and the rebound readings were recorded three times. The three rebound values are converted to rebound values expressed as a percentage; their median is the rebound value of the sample. If two samples are taken, their arithmetic mean is calculated.8 test reportThe test report should include the following. a) Sample description. 1) Detailed description and source of the sample; 2) Specification of the compound and vulcanization conditions (if known); 3) preparation of the sample, such as molding or die cutting; 4) the process of pretreatment of the sample; b) Test methods and test descriptions. 1) The national standard cited (valid); 2) the type of instrument used, the diameter of the punch, the mass of the punch and the impact speed; 3) a method of holding a sample; 4) test temperature; 5) The time and temperature of the sample adjustment before the test; 6) any non-standardized procedures used; c) Test results. 1) the number of samples tested; 2) The rebound resilience expressed as a percentage of the sample used, as calculated in 7.3; d) Test date.Appendix A(informative appendix) Non-standard sample A. 1 non-standard diameter sample For specimens whose thickness meets the standard but whose diameter is larger than the standard and the maximum value does not exceed 53 mm, the test may also be carried out. If you increase the clamping force (See Table A.1), then the results are similar to the standard conditions and the standard rebound resilience measured by the instrument. A. 2 non-standard thickness samples For specimens with a thickness less than (12.5 ± 0.5) mm, the knots close to the standard resilience can also be measured using the following two different methods. /m3 is the principle of the same constant value. A. 2.1 Method A. Adjusting the impac......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 1681-2009_English be delivered?Answer: Upon your order, we will start to translate GB/T 1681-2009_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of GB/T 1681-2009_English with my colleagues?Answer: Yes. 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