1、Designation: D2659 11Standard 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 last revis
2、ion. 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 mechanicalproperties of blown thermoplastic containers, whether blowncommercially
3、or in the laboratory, loaded under columnarcrush conditions at a constant rate of compressive deflection.NOTE 1Although this test method was developed specifically forblow-molded containers, the general procedure can also be applied tocontainers of suitable geometries produced by other means, for ex
4、ample,thermoforming, injection molding, etc.1.2 The values stated in SI units are to be regarded as thestandard.NOTE 2There is no known ISO equivalent to this standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of
5、 the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD4976 Specification for Polyethylene Plastics Molding
6、 andExtrusion MaterialsE4 Practices for Force Verification of Testing MachinesE83 Practice for Verification and Classification of Exten-someter Systems3. Terminology3.1 Definitions:3.1.1 crushing yield loadthe first load at which an in-crease of deflection occurs with no increase in load in acompres
7、sive crushing test (expressed in units of kilograms (orpounds) of load).NOTE 3In some cases, usually as a result of design or styling features,or both, of a specific container, multiple values of the crushing yield loadare be observed, that is, a small deflection occurs with no increase or witha dec
8、rease in the crush load, followed by resumption of the normal crushload change with deflection. This phenomenon cannot be ignored in theevaluation of the column crush properties of a blown thermoplasticcontainer, since it can be a very useful designated failure point for theapplication under conside
9、ration. The load at which this abrupt changeoccurs can be chosen as a crushing yield load for study. In such a case, thereport of results should be accompanied by a proper description of thecrushing yield load selected.3.1.2 crushing load at failurethe crushing load applied toa blown thermoplastic c
10、ontainer that produces a failure byfracture or parting of the material in any portion of saidcontainer (expressed in kilograms (or pounds).3.1.3 deflection at crushing yield loadthe decrease inlength of the container specimen produced at the crushing yieldload along the center line of testing (axis
11、of crushing, see Fig.1) (expressed in millimetres (or inches).3.1.4 apparent crushing stiffnessthe ratio of the crushingload to the corresponding deflection at a point on the linearportion of the crushing load deflection curve (expressed innewtons per metre (or pounds per inch).4. Significance and U
12、se4.1 Column crush tests only provide information about thecrush properties of blown thermoplastic containers whenemployed under conditions approximating those under whichthe tests are conducted.4.2 The column crush properties include the crushing yieldload, deflection at crushing yield load, crushi
13、ng load at failure,and apparent crushing stiffness. Blown thermoplastic contain-ers made from materials that possess a low order of ductilitycan fail in crushing by brittle fracture. In such cases, thecrushing yield load is equivalent to the crushing load at failure.Blown thermoplastic containers ma
14、de of ductile materials donot always exhibit a crushing load at failure although they willnormally provide a crushing yield load value.4.3 Column crush tests provide a standard method ofobtaining data for research and development, applications,design, quality control, acceptance or rejection under s
15、pecifi-cations, and special purposes. The tests cannot be consideredsignificant for engineering design in applications differing1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.19 on Molded and ExtrudedProducts.Current
16、edition approved Sept. 1, 2011. Published September 2011. Originallyapproved in 1967. Last previous edition approved in 2005 as D2659 - 1995 (2005).DOI: 10.1520/D2659-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annu
17、al Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.widely fro
18、m the load - time scale of the standard test. Suchapplications require additional tests such as impact, creep, andfatigue.5. Apparatus5.1 Testing MachineAny suitable testing machine capableof control of constant-rate-of-crosshead movement and com-prising essentially the following:5.1.1 Drive Mechani
19、smA drive mechanism imparting thecrosshead movable member of a uniform, controlled velocitywith respect to the fixed member, this velocity to be regulatedas specified in Section 9.5.1.2 Load IndicatorA load-indicating mechanism ca-pable of showing the total crushing load carried by the testspecimen.
20、 The mechanism shall be essentially free frominertia-lag at the specified rate of testing and shall indicate thecrushing load with an accuracy of 61 %. The accuracy of thetesting machine shall be verified at least once a year, inaccordance with Practices E4.5.2 ExtensometerA suitable instrument for
21、determiningthe distance between the two surfaces of load application onthe test specimen at any time during the test. It is desirable thatthis instrument automatically record this distance, or anychange in it as a function of the crushing load on the testspecimen. The instrument shall be essentially
22、 free of inertia-lagat the specified rate of loading and shall conform to therequirements for a Class B-2 extensometer, as defined inPractice E83.6. Test Specimens6.1 The specimens for testing shall be the blown thermo-plastic container under investigation. The specimens must befree of obvious defec
23、ts such as rocker bottoms or bent necks,unless such defects constitute a variable to be studied. Thesurfaces of the container that bear on the fixed and movablemembers of the testing machine shall be parallel to each other.NOTE 4In the event that the bearing surface of the blown thermo-plastic conta
24、iner deviates noticeably from the parallel relationship, theconstruction and use of a suitable testing jig will be necessary. This jigshall be attached to that crosshead member of the testing machine thatcontacts the nonparallel surface of the container. In the event of slippageon the machine crushi
25、ng surfaces, a nonslip material such as masking tapecan be applied to the slipping member of the testing machine.7. Conditioning7.1 ConditioningCondition the test specimens at 23 62C (73.4 6 3.6F) and 50 6 10 % relative humidity for notless than 40 h prior to test in accordance with Procedure A ofPr
26、actice D618, unless otherwise specified by contract or therelevant ASTM material specification. In cases of disagree-ment, the tolerances shall be 61C (61.8F) and 65%relative humidity.7.2 Test ConditionsConduct tests in the standard labora-tory atmosphere of 23 6 2C (73.4 6 3.6F) and 50 6 10 %relati
27、ve humidity, unless otherwise specified by contract or therelevant ASTM material specification. In cases of disagree-ment, the tolerances shall be 61C (61.8F) and 65%relative humidity.NOTE 5Alternatively, blown thermoplastic container test specimensthat are made of materials known to be insensitive
28、to changes of relativehumidity, can be conditioned at the Standard Laboratory Temperature of23 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 onany given axis of crushing. If more than one axis
29、of crushingis to be studied, at least 20 specimens shall be tested for eachaxis.8.2 Specimens that fail at some obvious fortuitous flaw shallbe discarded and retests made on additional specimens, unlesssuch flaws constitute a variable to be studied. The data shall bediscarded and the number of rejec
30、ted specimens noted.9. Speed of Testing9.1 Speed of testing shall be the relative rate of motion ofthe fixed and movable members of the testing machine duringthe test. Rate of motion of the movable member, when themachine is running idle, can be used if it can be shown that theresulting speed of tes
31、ting is within the limits of variationallowed.9.2 The speed of testing shall be constant within 610 %.9.3 The speed of testing shall be chosen in the range from12.5 mm (0.50 in.)/min to 50.0 mm (2.0 in.)/min.NOTE 6Round-robin tests have shown that precision of measurementsis less than satisfactory w
32、hen testing speeds less than 12.5 mm (0.50in.)/min or more than 50.0 mm (2.0 in.)/min were employed for a limitednumber of blown thermoplastic container styles and designs. Lower orhigher testing speeds are acceptable if it can be shown that the precisionof the resulting measurements is satisfactory
33、.NOTE 7A testing speed of 25.0 6 2.5 mm (1.0 6 0.1 in.)/min hasbeen found useful. It is desirable, however, that several speeds of testingbe evaluated when a new blown thermoplastic container is to be studied,since performance behavior can be affected by different testing speeds.10. Procedure10.1 De
34、termine the weight of the test specimen to thenearest 0.1 g.FIG. 1 Typical Crushing AxesD2659 11210.2 Place the test specimen between the members of thetesting machine, taking care to align the axis of crushing withthe center line of the movable member of the testing machineand to ensure that the be
35、aring surfaces of the test specimen areparallel to the bearing surfaces of the testing machine fixed andmovable members. Ensure adequate venting to allow equaliza-tion of air pressure during the crushing test (see Note 8).Adjustthe movable member of the testing machine until it justcontacts the top
36、of the test specimen.10.3 Carefully select the axis of crushing so as to providemeasurements along the desired blown thermoplastic containercenter line. Fig. 1 shows typical axes of crushing selections.NOTE 8Round-robin tests have shown that pressure changes within asealed blown thermoplastic contai
37、ner during column crush tests willchange the values obtained. If the seal is not consistent, the accuracy andprecision of the measurement will be adversely affected. Furthermore,testing of sealed specimens can result in explosive failure, so that testingis not recommended without proper safeguards.
38、Thus, venting of thespecimens is necessary, not only to ensure accuracy and precision ofmeasurements, but, also, as a safety precaution, and to ensure a correctbasis for obtaining comparable measurement data. In the case of (a) and(c) in Fig. 1, this can be accomplished by allowing the container ope
39、ningto remain unsealed and drilling a hole in the testing machine member thatbears on this opening.10.4 If the crushing yield load data only are desired, proceedas follows:10.4.1 Set the speed control at the desired speed of testingand start the machine.10.4.2 Record the load carried by the specimen
40、 as defined in3.1 and the location of the yield or failure of the specimen.10.5 If crush load - deflection data are desired, proceed asfollows:10.5.1 Attach or adjust the extensometer, or both.10.5.2 Set the speed control at the desired speed of testingand start the machine.10.5.3 Record crush loads
41、 and corresponding deflection atappropriate intervals of deflection, or, if the test machine isequipped with an automatic recording device, record the crushload - deflection curve to the desired end point. In either case,also record the location of the yield or failure of the specimen.11. Calculatio
42、n11.1 Crushing Yield LoadDetermine the crushing yieldload by observation of that point on the crush load - deflectioncurve at which an increase in deflection occurs without anincrease in crush load. Express the result in kilograms (orpounds) and report to three significant figures.11.2 Crushing Load
43、 at FailureDetermine the crushingload at failure by observation of that point on the crush load -deflection curve that corresponds to the failure by fracture orparting of the material. Express the results in kilograms (orpounds) and report to three significant figures.11.3 Deflection at Crushing Yie
44、ld LoadDetermine thedeflection at crushing yield load by observation of the decreasein length produced in gage length of the specimen at thecrushing yield load. Express the results in millimetres (orinches) and report the result to three significant figures.11.4 Apparent Crushing StiffnessCalculate
45、the apparentcrushing stiffness by selecting any point on the initial straightline portion of the crush load - deflection curve and dividingthe crush load at this point by the corresponding deflection.Express the results in newtons per metre (or pounds per inch)and report to three significant figures
46、.11.5 If the crushing load-deflection curve exhibits a non-linear response, this shall be reported in accordance with12.1.11.11.6 For each sample of at least 20 test specimens, calculateto three significant figures the arithmetic mean of all valuesobtained and report as the “average value” for the p
47、articularproperty in question.11.7 For each lot of samples tested, calculate the standarddeviation (estimated) as follows and report to two significantfigures.s 5 =(X22 nX2!/n 2 1! (1)where:s = estimated standard deviation,X = value of a single observation,n = number of observations, andX= arithmeti
48、c mean of the set of observations.12. Report12.1 Report the following information:12.1.1 Complete identification of the blown thermoplasticcontainer tested, such as type, source, manufacturer, form, andprevious history,12.1.2 Purpose of test,12.1.3 Conditioning procedure used,12.1.4 Atmospheric cond
49、itions in test room,12.1.5 Description of axis of crushing used,12.1.6 Number and weight of specimens, average value, andstandard deviation,12.1.7 Speed of testing,12.1.8 Crushing yield load, average value, and standarddeviation,12.1.9 Crushing strength at failure, average value, standarddeviation, and description of failure,12.1.10 Deflection at crushing yield point, average value,and standard deviation,12.1.11 Apparent crushing stiffness, average value, andstandard deviation, as well as specification at the point chosenin the case of a crush lo
