1、Designation: D5419 09Standard Test Method forEnvironmental Stress Crack Resistance (ESCR) of ThreadedPlastic Closures1This standard is issued under the fixed designation D5419; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar of last 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 determines the susceptibility ofthreaded plastic closures to failure due to environmental stre
3、sscracking (ESC).1.2 In use, threaded plastic closures can contact agents thatappreciably reduce the stress at which cracks form. Examplesof such agents are: soaps, detergents, oils, and liquid bleaches.1.3 Major factors that influence environmental stress crackresistance (ESCR) of threaded plastic
4、closures include theclosure material(s), closure design, molded-in stress, andapplied stress.1.4 This procedure can be applied to all closures, but isparticularly applicable to closures made from plastics based onpolypropylene (PP) or polystyrene (PS).1.5 The values stated in SI units are to be rega
5、rded as thestandard.1.6 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
6、 use. Specific precau-tionary statements are given in Section 8 and 6.2.NOTE 1There is no known ISO equivalent to this test method.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1600 Terminology for Abbreviated Term
7、s Relating toPlasticsD2911 Specification for Dimensions and Tolerances forPlastic BottlesD3198 Test Method forApplication and Removal Torque ofThreaded or Lug-Style ClosuresE145 Specification for Gravity-Convection and Forced-Ventilation OvensE691 Practice for Conducting an Interlaboratory Study toD
8、etermine the Precision of a Test Method3. Terminology3.1 DefinitionsExcept for those terms below, see Termi-nologies D883 and D1600.3.2 Definitions of Terms Specific to This Standard:3.2.1 assemblyclosure applied to a bottle finish.3.2.2 failureduring this test, any visible crack.3.2.2.1 DiscussionA
9、 crack does not have to penetrate theclosure wall to be considered a failure.3.2.3 finishfixture representing the threaded portion of thebottle.3.2.4 threaded closurepart applied to seal bottle as speci-fied in Specification D2911.4. Summary of Test Method4.1 This test method consists of applying cl
10、osures at aspecified application torque to rigid finishes (of polysulfone orother appropriate resin), immersing the assembly in a potentialstress-cracking agent, and observing and reporting time-to-failure.5. Significance and Use5.1 This test method compares closures for ESCR. Suitablevariables are:
11、 closure materials, closure designs, processes,applied torque, and stress-crack agents.5.2 Results can be used for estimating shelf life of closuresin terms of ESCR. This requires that the user has calibratedfailure time in this test to failure time in the field for actualpackaging systems.6. Appara
12、tus6.1 Wide-Mount Gallon Jars, glass, PET, or other suitablematerial. Must have lined closures to ensure air-tight seal. Useone jar per sample.6.2 Circulating-Air Oven, capable of maintaining a tem-perature of 50 6 1C (critical in this application). SeeSpecification E145 for a procedure for confirmi
13、ng satisfactoryuniformity of temperature within the oven. There is no air-flow1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.19 on Film and Sheeting.Current edition approved Nov. 15, 2009. Published December 2009. Ori
14、ginallyapproved in 1993. Last previous edition approved in 2003 as D5419 95(2003).DOI: 10.1520/D5419-09.2For 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 standard
15、s 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.requirement in this application. An environmental room withthese properties
16、is also suitable. (WarningA high-temperature safety switch is highly recommended on this oven.Some test liquids can cause extreme pressure to build up uponheating. Under these conditions the test jars may rupture withexplosive force. The override cutoff switch should be set toturn off the oven if th
17、e test temperature is exceeded by 10C ormore.)6.3 Tongs, for sample removal and inspection.6.4 Bottle Finishes, polysulfone or other material of equiva-lent stiffness and thermal coefficient of expansion, to whichclosures are applied. These can be made by injection moldingor by machining rod stock.
18、See Fig. 1 for a drawing of a typicalfixture. Use an appropriate size based on closure and bottlespecifications.6.5 Torque Meter, with capacity of at least 5 torque Nm,calibrated or verified within the past 12 months.6.6 Plastic Test Closures, lined or unlined closure based onspecifications.NOTE 2To
19、 ensure that full crystallization has essentially beenachieved, PP-based closures should condition for at least three weeksbefore testing and PS closures for at least 16 h.NOTE 3To convert lbf-in. torque to Nm torque, multiply by 0.113.7. Reagents and Materials7.1 Test SolutionUse solution for which
20、 the closure isintended.8. Hazards8.1 Always wear protective equipment, such as goggles,gloves, and aprons, appropriate to the product hazard whensetting up or inspecting closures.9. Test Specimens9.1 Normal sample size is 20 closures, typical of lots to betested. It is strongly advisable to run the
21、 test in duplicate (twosets of 20) or to sample more than one lot.9.2 Visually inspect each closure to be tested. Replace anythat appear defective or irregular.10. Conditioning10.1 ConditioningAfter aging in accordance with 6.6,condition closures and bottle finishes at 23 6 2C and 50 610 % relative
22、humidity for not less than 40 h prior to test, inaccordance with Procedure A of Practice D618 unless other-wise specified by agreement or the relevant ASTM materialspecification. Condition test solution at 50 6 1C until itreaches 50 6 1C (16 h normally required).NOTE 1Tolerances for Dimensions T, E,
23、 and S shall be in accordance with Specification D2911.FIG. 1 Typical FixtureD5419 09210.2 Test ConditionsConduct all tests at 50 6 2C, unlessinstructed otherwise.11. Procedure11.1 Apply closures to bottle finishes (see Test MethodD3198). Unless otherwise specified, apply torque to a toleranceof 65
24、% using one of the following values:11.1.1 A value corresponding to the upper limit of immedi-ate removal torque in production (rule of thumb: applicationtorque = 1.05 3 immediate removal torque), or11.1.2 A nominal value based on the closure diameter (ruleof thumb: torque, Nm = closure diameter, mm
25、 3 0.08), or11.1.3 A value agreed upon between the laboratory and thecustomer.11.2 Place 20 assemblies in jars. Fill jars with enough testsolution at 50 6 1C to cover all assemblies. Wipe any testsolution from jar-finish area. Cap jars and hand tighten.11.3 Place jars on test at 50 6 1C. Check and r
26、ecord thetemperature of test area daily and maintain it within thespecified limits.11.4 Inspect the assemblies daily except on weekends.Move jars from test condition to inspection area. Do not allowto be off test more than 60 min. Remove the assembliesindividually, using tongs on the bottle finishes
27、, not the closures.NOTE 4It is recommended that the inspection frequency be increasedduring periods of known high-failure rates. Delaying the start of thesecond duplicate sample facilitates this; however, frequency of torquereapplication should remain at daily intervals except on weekends.11.5 After
28、 inspection, set aside failures. Reapply initialtorque to nonfailing closures, return them to jars and move jarsback to test condition. Do not remove or loosen closures. If testsolution degrades with age, replace it often enough that thefailure rate is not significantly reduced. If closure cracks on
29、retorqueing, count this as a failure on the next inspection.11.6 For each failure, note the time, description, and loca-tion of failure.11.7 Any sample (jar) can be removed and the test termi-nated when there have been failures on at least two inspections,and a total of at least 11 out of 20 closure
30、s have failed. Recordinspections even on days when there are no failures.NOTE 5If testing against an F50specification, the test may beterminated if no more than 1 closure out of 20 fails by the specificationtime.12. Calculation12.1 Calculate closures predicted to fail at any given timeby the followi
31、ng equation:failures, % 5 n 2 0.5!/N 3 100 (1)where:n = cumulative number of closures that have failed as ofthe given time, andN = number of closures tested (20 unless otherwisestated).12.2 F25Failure TimePlot the data on Weibull probabilitygraph paper with days on the log scale and percent failure
32、onthe probability scale. When more than one closure fails on agiven inspection, use the average % failing on that inspectionfor the plotting position (see the example in Appendix X1).Draw the best fitting straight line for the plot. The daysindicated at the intersection of the data line with the 50
33、%failure level probability line shall be reported as the F50failuretime. See Fig. 2 for example.NOTE 6The plot or calculations, or both, may be made on computerwith suitable software.13. Report13.1 Report the following information:13.1.1 Closure identification, specification number (if appli-cable),
34、 manufacturer, molding location, molding date, lotnumber, liner description (if applicable), molding machine,resin, mold and cavity number(s), process conditions,13.1.2 Test solution name and composition/analysis,13.1.3 Application torque,13.1.4 Date and time of each inspection and location of eachf
35、ailure, and13.1.5 Failure time (F50).14. Precision and Bias314.1 PrecisionTable 1 is based on a round robin con-ducted in 1995 in accordance with Practice E691, involvingone material tested by 12 laboratories. All of the samples wereprepared at one source. Each test result was based on 20individual
36、determinations. Each laboratory obtained two testresults for each material. (WarningThe following explana-tions of r and R (14.1.1.1-14.1.1.3) are only intended to presenta meaningful way of considering the approximate precision of3A research report is currently being written.FIG. 2 F50Failure TimeD
37、5419 093this test method. The data in Table 1 should not be appliedrigorously to the acceptance or rejection of material, as thosedata are specific to the round robin and may not be represen-tative of other lots, conditions, materials, or laboratories. Usersof this test method should apply the princ
38、iples outlined inPractice E691 to generate data specific to their laboratory andmaterials or between specific laboratories. The principles of14.1.1.1-14.1.1.3 would then be valid for such data.)14.1.1 Concept of r and Rif Srand SRhave been calcu-lated from a large enough body of data,14.1.1.1 Repeat
39、ability, (r)(Comparing two test results forthe same material, obtained by the same operator using thesame equipment on the same day.) Judge the two test results asnot equivalent if they differ by more than the r value for thatmaterial.14.1.1.2 Reproducibility, (R)(Comparing two test resultsfor the s
40、ame material, obtained by different operators usingdifferent equipment on different days.) Judge the two testresults as not equivalent if they differ by more than the R valuefor that material.14.1.1.3 Any judgment determined in accordance with14.1.1.1 and 14.1.1.2 would have an approximate 95 % (0.9
41、5)probability of being correct.14.2 BiasThere are no recognized standards by which toestimate the bias of this test method.15. Keywords15.1 closures; environmental stress crack resistance(ESCR); failure; plastic; stress crack; threaded plastic closuresAPPENDIX(Nonmandatory Information)X1. EXAMPLE OF
42、 GRAPHICAL DETERMINATION OF F50X1.1 Data (See Table X1.1):X1.2 Plotting Positions for n = 20 (See Table X1.2):X1.3 X-Axis Values for Example:X1.3.1 First failures occurred at 5 days, so the first X valueis 5 days.X1.3.2 The second X value is 6 days.X1.3.3 The test terminated after 6 days (19 failure
43、s).X1.4 Y-Axis Values for Example:X1.4.1 For the first point, the Y value is the average of theplot position for 1 and 10 closures failed5 2.5 1 47.5!/2 5 25 % (X1.1)X1.4.2 For the second point, the Y value is the average ofthe plot position for 11 and 19 closures failed5 52.5 1 92.5!/2 5 72.5 % (X1
44、.2)X1.4.3 Graph (See Fig. 2):X1.5 Determination of F50Interpolate the line at the“percent failing” value of 50 on the Y-axis, and read of f “daysto failure” on the X-axis.TABLE 1 F50, DaysClosures Testedin BleachAverage SrASRBrCRD28 mm-Polypropylene5.1 0.8 1.5 2.2 4.1ASris the within-laboratory stan
45、dard deviation.BSRis the between-laboratories standard deviation.Cr is the within-laboratory repeatability limit = 2.8 Sr.DR is the between-laboratory reproducibility limit = 2.8 SR.TABLE X1.1 DataNo. of Dayson TestNo. of Closures Failingon This DateTotal No. of ClosuresFailed to Date30 040510 169 9
46、TABLE X1.2 Plotting Positions for n =20No. of Closures Failed Plotting Position, %12.5273 12.54 17.55 22.56 27.57 32.58 37.59 42.510 47.511 52.512 57.513 62.514 67.515 72.516 77.517 82.518 87.519 92.520 97.5D5419 094SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to t
47、his standard since the last issue(D5419 - 95(2003) that may impact the use of this standard. (November 15, 2009)(1) Edited ISO equivalency statement.(2) Removed permissive language in the procedural sections.(3) Changed tolerances for test temperature to conform torequirements in 6.2.(4) Updated con
48、ditioning requirements(5) Numerous editorial changesASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rig
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