1、Designation: D2659 11D2659 16Standard Test Method forColumn Crush Properties of Blown ThermoplasticContainers1This standard is issued under the fixed designation D2659; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of mechanical properties of blown thermoplastic containers, whether blowncomm
3、ercially or in the laboratory, loaded under columnar crush conditions at a constant rate of compressive deflection.NOTE 1Although this test method was developed specifically for blow-molded containers, the general procedure can also be applied to containersof suitable geometries produced by other me
4、ans, for example, thermoforming, injection molding, etc.1.2 The values stated in SI units are to be regarded as the standard.NOTE 2There is no known ISO equivalent to this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the re
5、sponsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD4976
6、 Specification for Polyethylene Plastics Molding and Extrusion MaterialsE4 Practices for Force Verification of Testing MachinesE83 Practice for Verification and Classification of Extensometer Systems3. Terminology3.1 DefinitionsFor definitions of terms used in this test method and associated with pl
7、astics issues refer to the terminologycontained in ASTM D883.3.2 Definitions:Definitions of Terms Specific to This Standard:3.2.1 apparent crushing stiffnessthe ratio of the crushing load to the corresponding deflection at a point on the linear portionof the crushing load deflection curve (expressed
8、 in newtons per metre (or pounds per inch).3.2.2 columna compression member that is axially loaded.3.2.3 crushing load at failurethe crushing load applied to a blown thermoplastic container that produces a failure by fractureor parting of the material in any portion of said container (expressed in k
9、ilograms (or pounds).3.2.4 crushing yield loadthe first load at which an increase of deflection occurs with no increase in load in a compressivecrushing test (expressed in units of kilograms (or pounds) of load).NOTE 3In some cases, usually as a result of design or styling features, or both, of a sp
10、ecific container, multiple values of the crushing yield load arebe observed, that is, a small deflection occurs with no increase or with a decrease in the crush load, followed by resumption of the normal crush loadchange with deflection. This phenomenon cannot be ignored in the evaluation of the col
11、umn crush properties of a blown thermoplastic container, sinceit can be a very useful designated failure point for the application under consideration. The load at which this abrupt change occurs can be chosen as acrushing yield load for study. In such a case, the report of results should be accompa
12、nied by a proper description of the crushing yield load selected.1 This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.19 on Film, Sheeting, and MoldedProducts.Current edition approved Sept. 1, 2011May 1, 2016. Published S
13、eptember 2011May 2016. Originally approved in 1967. Last previous edition approved in 20052011 asD2659 - 1995 (2005).D2659 - 11. DOI: 10.1520/D2659-11.10.1520/D2659-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual
14、Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be tec
15、hnically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of thi
16、s standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.2 crushing load at failurethe crushing load applied to a blown thermoplastic container that produces a failure by fractureor parting of the material in any portion of said
17、container (expressed in kilograms (or pounds).3.2.5 deflection at crushing yield loadthe decrease in length of the container specimen produced at the crushing yield loadalong the center line of testing (axis of crushing, see Fig. 1) (expressed in millimetres (or inches).3.2.6 apparent crushing stiff
18、nessgage lengththe ratio of the crushing load to the corresponding deflection at a point on thelinear original length of that portion of the crushing load deflection curve (expressed in newtons per metre (or pounds perinch).specimen over which strain or change in length is determined.4. Significance
19、 and Use4.1 Column crush tests only provide information about the crush properties of blown thermoplastic containers when employedunder conditions approximating those under which the tests are conducted.4.2 The column crush properties include the crushing yield load, deflection at crushing yield loa
20、d, crushing load at failure, andapparent crushing stiffness. Blown thermoplastic containers made from materials that possess a low order of ductility can fail incrushing by brittle fracture. In such cases, the crushing yield load is equivalent to the crushing load at failure. Blown thermoplasticcont
21、ainers made of ductile materials do not always exhibit a crushing load at failure although they will normally provide a crushingyield load value.4.3 Column crush tests provide a standard method of obtaining data for research and development, applications, design, qualitycontrol, acceptance or reject
22、ion under specifications, and special purposes. The tests cannot be considered significant forengineering design in applications differing widely from the load - time scale of the standard test. Such applications requireadditional tests such as impact, creep, and fatigue.5. Apparatus5.1 Testing Mach
23、ineAny suitable testing machine capable of control of constant-rate-of-crosshead movement and comprisingessentially the following:5.1.1 Drive MechanismA drive mechanism imparting the crosshead movable member of a uniform, controlled velocity withrespect to the fixed member, this velocity to be regul
24、ated as specified in Section 9.5.1.2 Load IndicatorA load-indicating mechanism capable of showing the total crushing load carried by the test specimen.The mechanism shall be essentially free from inertia-lag at the specified rate of testing and shall indicate the crushing load withan accuracy of 61
25、%. The accuracy of the testing machine shall be verified at least once a year, in accordance with Practices E4.5.2 ExtensometerA suitable instrument for determining the distance between the two surfaces of load application on the testspecimen at any time during the test. It is desirable that this in
26、strument automatically record this distance, or any change in it asa function of the crushing load on the test specimen. The instrument shall be essentially free of inertia-lag at the specified rate ofloading and shall conform to the requirements for a Class B-2 extensometer, as defined in Practice
27、E83.5.3 Load Application FixturesA means shall be provided to apply the crushing load to the specimen such as a stationary andmoveable parallel platens. The fixtures shall be of sufficient rigidity to prevent fixture deformation due to the applied crushing load.FIG. 1 Typical Crushing AxesD2659 162N
28、OTE 4In the event that the bearing surface of the blown thermoplastic container deviates noticeably from the parallel relationship, the constructionand use of a suitable testing jig will be necessary. This jig shall be attached to that crosshead member of the testing machine that contacts the nonpar
29、allelsurface of the container. In the event of slippage on the machine crushing surfaces, a nonslip material such as masking tape can be applied to the slippingmember of the testing machine.6. Test Specimens6.1 The specimens for testing shall be the blown thermoplastic container under investigation.
30、 The specimens must be free ofobvious defects such as rocker bottoms or bent necks, unless such defects constitute a variable to be studied. The surfaces of thecontainer that bear on the fixed and movable members of the testing machine shall be parallel to each other.NOTE 4In the event that the bear
31、ing surface of the blown thermoplastic container deviates noticeably from the parallel relationship, the constructionand use of a suitable testing jig will be necessary. This jig shall be attached to that crosshead member of the testing machine that contacts the nonparallelsurface of the container.
32、In the event of slippage on the machine crushing surfaces, a nonslip material such as masking tape can be applied to the slippingmember of the testing machine.7. Conditioning7.1 ConditioningCondition the test specimens at 23 6 2C (73.4 6 3.6F) and 50 6 10 % relative humidity for not less than40 h pr
33、ior to test in accordance with Procedure A of Practice D618, unless otherwise specified by contract or the relevant ASTMmaterial specification. In cases of disagreement, the Temperature and humidity tolerances shall be 61C (61.8F) and 65 %relative humidity.in accordance with Section 7 of Practice D6
34、18 unless specified differently by contract or material specification.7.2 Test ConditionsConduct tests in the standard laboratory atmosphere of 23 6 2C (73.4 6 3.6F) and 50 6 10 % relativehumidity,at the same temperature and humidity used for conditioning with tolerances in accordance with Section 7
35、 of PracticeD618 unless otherwise specified by contract or the relevant ASTM material specification. In cases of disagreement, the tolerancesshall be 61C (61.8F) and 65 % relative humidity.NOTE 5Alternatively, blown thermoplastic container test specimens that are made of materials known to be insens
36、itive to changes of relativehumidity, can be conditioned at the Standard Laboratory Temperature of 23 6 2C (73.4 6 3.6F) for a period of 24 h, unless otherwise specified.8. Number of Test Specimens8.1 At least 20 specimens shall be tested for each sample on any given axis of crushing. If more than o
37、ne axis of crushing isto be studied, at least 20 specimens shall be tested for each axis.8.2 Specimens that fail at some obvious fortuitous flaw shall be discarded and retests made on additional specimens, unless suchflaws constitute a variable to be studied. The data shall be discarded and the numb
38、er of rejected specimens noted.9. Speed of Testing9.1 Speed of testing shall be the relative rate of motion of the fixed and movable members of the testing machine during thetest. Rate of motion of the movable member, when the machine is running idle, can be used if it can be shown that the resultin
39、gspeed of testing is within the limits of variation allowed.9.2 The speed of testing shall be constant within 610 %.9.3 The speed of testing shall be chosen in the range from 12.5 mm (0.50 in.)/min to 50.0 mm (2.0 in.)/min.NOTE 6Round-robin tests have shown that precision of measurements is less tha
40、n satisfactory when testing speeds less than 12.5 mm (0.50 in.)/minor more than 50.0 mm (2.0 in.)/min were employed for a limited number of blown thermoplastic container styles and designs. Lower or higher testingspeeds are acceptable if it can be shown that the precision of the resulting measuremen
41、ts is satisfactory.NOTE 7A testing speed of 25.0 6 2.5 mm (1.0 6 0.1 in.)/min has been found useful. It is desirable, however, that several speeds of testing beevaluated when a new blown thermoplastic container is to be studied, since performance behavior can be affected by different testing speeds.
42、10. Procedure10.1 Determine the weight of the test specimen to the nearest 0.1 g.10.1 Place the test specimen between the membersfixtures of the testing machine, taking care to align the axis of crushing withthe center line of the movable member of the testing machine fixture and to ensure that the
43、bearing surfaces of the test specimenare parallel to the bearing surfaces of the testing machine fixed stationary and movable members.fixtures. Ensure adequate ventingto allow equalization of air pressure during the crushing test (see Note 8).Adjust the movable memberfixture of the testing machineun
44、til it just contacts the top of the test specimen.10.2 Carefully select the axis of crushing so as to provide measurements along the desired blown thermoplastic container centerline. Fig. 1 shows typical axes of crushing selections.NOTE 8Round-robin tests have shown that pressure changes within a se
45、aled blown thermoplastic container during column crush tests will changethe values obtained. If the seal is not consistent, the accuracy and precision of the measurement will be adversely affected. Furthermore, testing of sealedspecimens can result in explosive failure, so that testing is not recomm
46、ended without proper safeguards. Thus, venting of the specimens is necessary, notonly to ensure accuracy and precision of measurements, but, also, as a safety precaution, and to ensure a correct basis for obtaining comparableD2659 163measurement data. In the case of (a) and (c) in Fig. 1, this can b
47、e accomplished by allowing the container opening to remain unsealed and drilling a holein the testing machine member that bears on this opening.10.3 If the crushing yield load data only are desired, proceed as follows:10.3.1 Set the speed control at the desired speed of testing and start the machine
48、.10.3.2 Record the load carried by the specimen as defined in 3.13.2 and the location of the yield or failure of the specimen.10.4 If crush load - deflection data are desired, proceed as follows:10.4.1 Attach or adjust the extensometer, or both.10.4.2 Set the speed control at the desired speed of te
49、sting and start the machine.10.4.3 Record crush loads and corresponding deflection at appropriate intervals of deflection, or, if the test machine is equippedwith an automatic recording device, record the crush load - deflection curve to the desired end point. In either case, also recordthe location of the yield or failure of the specimen.11. Calculation11.1 Crushing Yield LoadDetermine the crushing yield load by observation of that point on the crush load - deflection curveat which an increase in deflection occurs without an increase in cr
