1、Designation: D 2659 95 (Reapproved 2005)Standard Test Method forColumn Crush Properties of Blown ThermoplasticContainers1This standard is issued under the fixed designation D 2659; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of mechanicalproperties of blown thermoplastic containers when lo
3、adedunder columnar crush conditions at a constant rate of compres-sive deflection. Any container, whether blown commercially orin the laboratory, may be used as the test specimen.1.2 The values stated in SI units are to be regarded as thestandard.NOTE 1There is no similar or equivalent ISO standard.
4、1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of 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 D
5、ocuments2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 4976 Specification for Polyethylene Plastics Molding andExtrusion MaterialsE4 Practices for Force Verification of Testing MachinesE83 Practice for Verification and Classification of Exten-someters3. Terminology3.1 Defi
6、nitions:3.1.1 crushing yield loadthe first load at which an in-crease of deflection occurs with no increase in load in acompressive crushing test. It is expressed in units of kilograms(or pounds) of load.NOTE 2In some cases, usually as a result of design or styling features,or both, of a specific co
7、ntainer, multiple values of the crushing yield loadmay be observed, a small deflection may occur with no increase or witha decrease 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 propert
8、ies of a blown thermoplasticcontainer, since it may be a very useful designated failure point for theapplication under consideration. The load at which this abrupt changeoccurs may be chosen as a crushing yield load for study. In such a case,the report of results should be accompanied by a proper de
9、scription of thecrushing yield load selected.3.1.2 crushing load at failurethe crushing load applied toa blown thermoplastic container that produces a failure byfracture or parting of the material in any portion of saidcontainer. It is expressed in kilograms (or pounds).3.1.3 deflection at crushing
10、yield loadthe decrease inlength of the container specimen produced at the crushing yieldload along the center line of testing (axis of crushing, see Fig.1). It is expressed in millimetres (or inches).3.1.4 apparent crushing stiffnessthe ratio of the crushingload to the corresponding deflection at a
11、point on the linearportion of the crushing load deflection curve. It is expressed innewtons per metre (or pounds per inch).4. Significance and Use4.1 Column crush tests provide information about the crush-ing properties of blown thermoplastic containers when em-ployed under conditions approximating
12、those under which thetests are made.4.2 The column crush properties include the crushing yieldload, deflection at crushing yield load, crushing load at failure,and apparent crushing stiffness. Blown thermoplastic contain-ers made from materials that possess a low order of ductilitymay fail in crushi
13、ng by brittle fracture. In such cases, thecrushing yield load is equivalent to the crushing load at failure.Blown thermoplastic containers made of ductile materials maynot exhibit a crushing load at failure although they willnormally provide a crushing yield load value.4.3 Column crush tests provide
14、 a standard method ofobtaining data for research and development, applications,design, quality control, acceptance or rejection under specifi-cations, and special purposes. The tests cannot be consideredsignificant for engineering design in applications differingwidely from the load - time scale of
15、the standard test. Suchapplications require additional tests such as impact, creep, andfatigue.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.20 on Plastic Products.Current edition approved July 15, 2005. Published Au
16、gust 2005. Originallyapproved in 1967. Last previous edition approved in 2001 as D 2659 - 1995 (2001).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards
17、Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.4 Before proceeding with this test method, referenceshould be made to the specification of the material being tested.Any test specimen prepara
18、tion, conditioning, dimensions, ortesting parameters, or combination thereof, covered in thematerials specification shall take precedence over those men-tioned in this test method. If there are no material specifica-tions, then the default conditions apply.5. Apparatus5.1 Testing MachineAny suitable
19、 testing machine capableof control of constant-rate-of-crosshead movement and com-prising essentially the following:5.1.1 Drive MechanismA drive mechanism imparting thecrosshead movable member of a uniform, controlled velocitywith respect to the fixed member, this velocity to be regulatedas specifie
20、d in Section 9.5.1.2 Load IndicatorA load-indicating mechanism ca-pable of showing the total crushing load carried by the testspecimen. 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
21、of thetesting machine shall be verified at least once a year, inaccordance with Practices E4.5.2 ExtensometerA suitable instrument for determiningthe distance between the two surfaces of load application onthe test specimen at any time during the test. It is desirable thatthis instrument automatical
22、ly record this distance, or anychange in it as a function of the crushing load on the testspecimen. The instrument shall be essentially 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.
23、1 The specimens for testing shall be the blown thermo-plastic container under investigation. The specimens must befree of obvious defects 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 movablemembe
24、rs of the testing machine shall be parallel to each other.NOTE 3In the event that the bearing surface of the blown thermo-plastic container deviates noticeably from the parallel relationship, theconstruction and use of a suitable testing jig will be necessary. This jigshall be attached to that cross
25、head member of the testing machine thatcontacts the nonparallel surface of the container. Similarly, some blownthermoplastic container designs may cause slippage on the machinecrushing surfaces. In this event, a nonslip material such as masking tapeshould be applied to the slipping member of the tes
26、ting machine.7. Conditioning7.1 ConditioningCondition the test specimens at 23 62C (73.4 6 3.6F) and 50 6 5 % relative humidity for not lessthan 40 h prior to test in accordance with Procedure A ofPractice D 618, for those tests where conditioning is required.In cases of disagreement, the tolerances
27、 shall be 61C(61.8F) and 62 % 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 5%relative humidity, unless otherwise specified in the test meth-ods. In cases of disagreement, the tolerances shall be 61C(61.8F) and 62 % relati
28、ve humidity.NOTE 4Blown thermoplastic container test specimens that are madeof materials known to be insensitive to changes of relative humidity, maybe conditioned at the Standard Laboratory Temperature of 23 6 2C (73.46 3.6F) for a period of 24 h, unless otherwise specified.8. Number of Test Specim
29、ens8.1 At least 20 specimens shall be tested for each sample onany given axis of crushing. If more than one axis 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, unless such fla
30、ws constitute avariable to be studied. The data should be discarded and thenumber of rejected 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
31、 themachine is running idle, may be used if it can be shown that theresulting speed of testing 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.NO
32、TE 5Round-robin tests have shown that precision of measurementsis less than satisfactory when 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 may be
33、used if it can be shown that the precision ofthe resulting measurements is satisfactory.NOTE 6A 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,sinc
34、e different performance behavior may be observed at different testingspeeds.FIG. 1 Typical Crushing AxesD 2659 95 (2005)210. Procedure10.1 Conduct the tests in the standard laboratory atmo-sphere of 50 6 5 % relative humidity and 23 6 2C (73.4 63.6F) unless the material used to make the specimen is
35、knownto be unaffected by change of relative humidity. In this lattercase, the tests may be conducted at the standard laboratorytemperature of 23 6 2C (73.4 6 3.6F).10.2 Determine the weight of the test specimen to thenearest 0.1 g.10.3 Place the test specimen between the members of thetesting machin
36、e, taking care to align the axis of crushing withthe center line of the movable member of the testing machineand to ensure that the bearing surfaces of the test specimen areparallel to the bearing surfaces of the testing machine fixed andmovable members. Provide a vent to allow equalization of airpr
37、essure during the crushing test. Adjust the movable memberof the testing machine until it just contacts the top of the testspecimen.NOTE 7The axis of crushing must be carefully selected so as toprovide measurements along the desired blown thermoplastic containercenter line. Fig. 1 shows typical axes
38、 of crushing selections.NOTE 8Round-robin tests have shown that pressure changes within asealed blown thermoplastic container 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,
39、testing of sealed specimens can result in explosive failure, so that testingis not recommended without proper safeguard. 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
40、 comparable measurement data. In the case of (a) and(c) in Fig. 1, this may be accomplished by allowing the container openingto 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
41、Set the speed control at the desired speed of testingand start the machine.10.4.2 Record the load carried by the specimen 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 extensom
42、eter, or both.10.5.2 Set the speed control at the desired speed of testingand start the machine.10.5.3 Record crush loads and corresponding deflection atappropriate intervals of deflection, or, if the test machine isequipped with an automatic recording device, record the crushload - deflection curve
43、 to the desired end point. In either case,also record the location of the yield or failure of the specimen.11. Calculation11.1 Crushing Yield LoadDetermine the crushing yieldload by observation of that point on the crush load - deflectioncurve at which an increase in deflection occurs without anincr
44、ease in crush load. Express the result in kilograms (orpounds) and report to three significant figures.11.2 Crushing Load 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 mate
45、rial. Express the results in kilograms (orpounds) and report to three significant figures.11.3 Deflection at Crushing Yield 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 result
46、s in millimetres (orinches) and report the result to three significant figures.11.4 Apparent Crushing StiffnessCalculate 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 corr
47、esponding deflection.Express the results in newtons per metre (or pounds per inch)and report to three significant figures.NOTE 9Some blown thermoplastic containers may not show linearbehavior in the crushing load-deflection curve (see 12.1.11).11.5 For each sample of at least 20 test specimens, calc
48、ulateto three significant figures the arithmetic mean of all valuesobtained and report as the “average value” for the particularproperty in question.11.6 For each lot of samples tested, calculate the standarddeviation (estimated) as follows and report to two significantfigures.s 5 =(X22 nX2!/n 2 1!
49、(1)where:s = estimated standard deviation,X = value of a single observation,n = number of observations, andX= arithmetic 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 conditions in test room,12.1.5 Description of axis of crushing used,12.1.6 Number and weight of specimens, average value, andstandard de
