Sakree If this test method is conducted at different temperatures on the same material, a more reliable estimate of the life-temperature relationship of polypropylene is determined. Whether your business is local or global, satm can ensure your products meet quality, health, environmental, safety, and social accountability standards for virtually any market around the world. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. Assurance Enabling you to identify and mitigate the intrinsic risk in your operations, aetm chains and business processes. Evaluating how your products and services meet and exceed quality, safety, sustainability and performance standards.

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A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval.

NOTE 1—The specied thermal levels in this test method are considered sufficiently severe to cause failure of commercial grades of heat-stable polypropylene within a reasonable period of time. If desired, lower temperatures can be applied to estimate the performance of polypropylene with lower heat stabilities.

The values in brackets are for information only. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. NOTE 2—This test method and ISO — are technically similar but different in preparation of test specimens, thickness of test specimen, measurement of the number of air ow changes in the ovens, and the number of air changes per hour required.

Terminology 3. Summary of Test Method 4. The time to failure of the material is taken as the 2. Referenced Documents 2. Current edition approved March 1, Published April Originally approved in Last previous edition approved in as D - Signicance and Use 5.

If desired, lower temperatures can be applied to estimate the performance of polypropylene materials with lower heat stability. If this test method is conducted at different temperatures on the same material, a more reliable estimate of the life-temperature relationship of polypropylene is determined.

This test method can be conducted at several temperatures and the data interpreted through use of the Arrhenius relation, by plotting the logarithms of times to failure against the reciprocals of the temperatures in kelvins K. Apparatus 6. A bimetallic-strip temperature switch has been found satisfactory.

It must be tested for bulb stability and standardized, in accordance with Test Method E NOTE 3—A Polished steel plates, 3 mm [0. The mold shall be capable of producing either a plaque having a thickness of 1. The lm must be free of wrinkles and foreign matter, such as lubricants and oils. The die must be sharp and free of nicks. Illustrations of suitable apparatus for biaxially and uniaxially rotated specimen holders are shown in Figs. Biaxial rotation increases the probability that all specimens will be exposed similarly.

In the case of dispute, the use of biaxial rotation shall be the reference method. The frequency of rotation about the horizontal and vertical axes shall be 1 to 3 min—1. Specimen Preparation 7. Plaques shall be prepared as follows: 7. Put enough of the sample into the cavity to ll it completely when molded.

A slight excess of material is desirable. Cover the loaded chase rst with a clean parting sheet and then a backing plate. Finally, put the assembled mold on the lower platen and close the press carefully until both platens are in contact with the assembly.

When the material has melted, apply sufficient pressure to form a void-free plaque in the 1. Flash cool the mold assembly by transferring to a water-cooled press or by water quenching. The standard specimen shall be 10 mm wide, 50 mm long, and 1. Edges shall be smoothed, if necessary, to remove imperfections introduced by cutting. In all cases the referee method will be based on compression molded die cut specimens.

NOTE 4—Failure test times for compression-molded and injectionmolded specimens may vary due to the skin surface effect and the distinctness or sharpness of the specimen edge. Conditioning 8. The anemometer shall be positioned directly in front of the oven outlet. Oven Parameters 9. Space the specimens 30 to 40 mm [1. Certain metals, such as aluminum, are known to affect with the long-term thermal endurance of some polypropylenes.

The area within 5 mm of the clips shall not be included in this evaluation. NOTE 9—When testing polypropylene containing recycled material localized discoloration often appears on the surface of the specimen within a few days of exposure to the heat.

This should not be interpreted as a failure unless the criteria of failure specied in NOTE 10—Visual inspection of the deterioration of the specimen surface, as a reliable evaluation of oxidative aging endurance, is justied by the fact that oxidation of propylene thermoplastics usually takes place on the surface of the material before propagating inward.

Report Precision and Bias Each material was supplied from one source, but the individual specimens were prepared at the laboratory that tested the specimens. Test specimens were 1. Each of two test results that was obtained by each laboratory was the average of ve individual determinations. Warning—The following explanations of r and R The data in Table 1 should not be rigorously applied to acceptance or rejection of material, as those data are specic to 9.

NOTE 6—The air velocity in the oven is dependent on the design of the oven and will not vary a great deal. It should be checked occasionally to determine if the blowers and other moving parts are functioning properly.

In no case should an anemometer be used to measure air ow at the test temperature. This method is described in Appendix X1. The advantages of the anemometer method is that is it quick, easy, and can be conducted on a more frequent basis to ensure that no changes have occurred in the settings or conditions in the oven. It is not an absolute measure. Users of this test method should apply the principles outlined in Practice E to generate data specic to their laboratory and materials, or between specic laboratories.

The principles of Keywords Knowing the volume of the interior of the oven and the cross-sectional area of the exhaust outlet and linear velocity of the air, the number of air volume changes occurring in the oven over a 1-h period can be calculated.

The vane shall be of equal or smaller diameter than the inside diameter of the exhaust outlet. The electronics within the anemometer shall be below the level of the heated exhaust to prevent the electronics from being heated and errors in calibration occurring. The unit should have a digital display of the air velocity.

Record this value as the linear air velocity in metres per minute. Move the vane away from the exhaust port and allow it to cool. Once cool, repeat the air velocity measurement. Ensure that the anemometer is cooled between each measurement to prevent heat buildup that might effect the electronics. Make a minimum of three measurements of the air velocity. NOTE X1. For the convenience of the user, Committee D20 has highlighted those changes that may impact the use of this test method.

This section may also include descriptions of the changes or reasons for the changes, or both. D — 1 Deleted D from 2. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility.

This standard is subject to revision at any time by the responsible technical committee and must be reviewed every ve years and if not revised, either reapproved or withdrawn.

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Thermal-Oxidative Stability ASTM D3012, GM9059P








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