1、Designation: D5419 09D5419 14Standard 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
2、, the year 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 of threaded plastic closures to failure due to environme
3、ntal stress cracking(ESC).1.2 In use, threaded plastic closures can contact agents that appreciably reduce the stress at which cracks form. Examples ofsuch agents are: soaps, detergents, oils, and liquid bleaches.1.3 Major factors that influence environmental stress crack resistance (ESCR) of thread
4、ed plastic closures include the closurematerial(s), closure design, molded-in stress, and applied stress.1.4 This procedure can be applied to all closures, but is particularly applicable to closures made from plastics based onpolypropylene (PP) or polystyrene (PS).1.5 The values stated in SIinch-pou
5、nd units are to be regarded as the standard. The values given in parentheses are forinformation only.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and hea
6、lth practices and determine the applicability of regulatorylimitations prior to use. Specific precautionary statements are given in Section 8 and 6.2.NOTE 1There is no known ISO equivalent to this test method.standard.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics
7、 for TestingD883 Terminology Relating to PlasticsD1600 Terminology for Abbreviated Terms Relating to PlasticsD2911 Specification for Dimensions and Tolerances for Plastic BottlesD3198 Test Method for Application and Removal Torque of Threaded or Lug-Style ClosuresE145 Specification for Gravity-Conve
8、ction and Forced-Ventilation OvensE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Terminology3.1 DefinitionsExcept for those terms below, see Terminologies D883 and D1600.3.2 Definitions of Terms Specific to This Standard:3.2.1 assemblyclosure appl
9、ied to a bottle finish.3.2.2 failureduring this test, any visible crack.3.2.2.1 Discussion1 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 Nov. 15, 200
10、9Nov. 15, 2014. Published December 2009December 2014. Originally approved in 1993. Last previous edition approved in20032009 as D5419 95D5419 09.(2003). DOI: 10.1520/D5419-09.10.1520/D5419-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serv
11、iceastm.org. For Annual 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.
12、Becauseit may not be technically 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 a
13、ppears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1A crack does not have to penetrate the closure wall to be considered a failure.3.2.3 finishfixture representing the threaded portion of the bottle.3.2.4
14、 threaded closurepart applied to seal bottle as specified in Specification D2911.4. Summary of Test Method4.1 This test method consists of applying closures at a specified application torque to rigid finishes (of polysulfone or otherappropriate resin), immersing the assembly in a potential stress-cr
15、acking agent, and observing and reporting time-to-failure.5. Significance and Use5.1 This test method compares closures for ESCR. Suitable variables are: closure materials, closure designs, processes, appliedtorque, and stress-crack agents.5.2 Results can be used for estimating shelf life of closure
16、s in terms of ESCR. This requires that the user has calibrated failuretime in this test to failure time in the field for actual packaging systems.6. Apparatus6.1 Wide-Mount Gallon Jars, glass, PET, or other suitable material. Must have lined closures to ensure air-tight seal. Use onejar per sample.6
17、.2 Circulating-Air Oven, capable of maintaining a temperature of 50 6 1C (critical in this application). See SpecificationE145 for a procedure for confirming satisfactory uniformity of temperature within the oven. There is no air-flow requirement inthis application. An environmental room with these
18、properties is also suitable. (WarningA high-temperature safety switch ishighly recommended on this oven. Some test liquids can cause extreme pressure to build up upon heating. Under these conditionsit is possible that the test jars maywill rupture with explosive force. The Set the override cutoff sw
19、itch should be set to turn offthe oven if the test temperature is exceeded by 10C or more.)6.3 Tongs, for sample removal and inspection.6.4 Bottle Finishes, polysulfone or other material of equivalent stiffness and thermal coefficient of expansion, to which closuresare applied. These can be made by
20、injection molding or by machining rod stock. See Fig. 1 for a drawing of a typical fixture. Usean appropriate size based on closure and bottle specifications.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
21、unlined closure based on specifications.NOTE 2To ensure that full crystallization has essentially been achieved, PP-based closures should condition for at least three weeks before testingand PS closures for at least 16 h.NOTE 3To convert lbf-in. torque to Nm torque, multiply by 0.113.7. Reagents and
22、 Materials7.1 Test SolutionUse solution for which the closure is intended.8. Hazards8.1 Always wear protective equipment, such as goggles, gloves, and aprons, appropriate to the product hazard when setting upor inspecting closures.9. Test Specimens9.1 Normal sample size is 20 closures, typical of lo
23、ts to be tested. It is strongly advisable to run the test in duplicate (two setsof 20) or to sample more than one lot.9.2 Visually inspect each closure to be tested. Replace any that appear defective or irregular.10. Conditioning10.1 ConditioningAfter aging in accordance with 6.6, condition closures
24、 and bottle finishes at 23 6 2C and 50 6 10 %relative humidity for not less than 40 h prior to test, in accordance with Procedure A of Practice D618 unless otherwise specifiedby agreement or the relevant ASTM material specification. Condition test solution at 50 6 1C until it reaches 50 6 1C (16 hno
25、rmally required).10.2 Test ConditionsConduct all tests at 50 6 2C, unless instructed otherwise.11. Procedure11.1 Apply closures to bottle finishes (see Test Method D3198). Unless otherwise specified, apply torque to a tolerance of 65 %using one of the following values:D5419 14211.1.1 A value corresp
26、onding to the upper limit of immediate removal torque in production (rule of thumb: applicationtorque = 1.05 immediate removal torque), or11.1.2 A nominal value based on the closure diameter (rule of thumb: torque, Nm = closure diameter, mm 0.08), or11.1.3 A value agreed upon between the laboratory
27、and the customer.11.2 Place 20 assemblies in jars. Fill jars with enough test solution at 50 6 1C to cover all assemblies. Wipe any test solutionfrom jar-finish area. Cap jars and hand tighten.11.3 Place jars on test at 50 6 1C. Check and record the temperature of test area daily and maintain it wit
28、hin the specifiedlimits.11.4 Inspect the assemblies daily except on weekends. Move jars from test condition to inspection area. Do not allow to be offtest more than 60 min. Remove the assemblies individually, using tongs on the bottle finishes, not the closures.NOTE 4It is recommended that the inspe
29、ction frequency be increased during periods of known high-failure rates. Delaying the start of the secondduplicate sample facilitates this; however, frequency of torque reapplication should remain at daily intervals except on weekends.11.5 After inspection, set aside failures. Reapply initial torque
30、 to nonfailing closures, return them to jars and move jars backto test condition. Do not remove or loosen closures. If test solution degrades with age, replace it often enough that the failure rateis not significantly reduced. If closure cracks on retorqueing, count this as a failure on the next ins
31、pection.11.6 For each failure, note the time, description, and location of failure.11.7 Any sample (jar) can be removed and the test terminated when there have been failures on at least two inspections, anda total of at least 11 out of 20 closures have failed. Record inspections even on days when th
32、ere are no failures.NOTE 5If testing against an F50 specification, the test may be terminated if no more than 1 closure out of 20 fails by the specification time.NOTE 1Tolerances for Dimensions T,E, and S shall be in accordance with Specification D2911.FIG. 1 Typical FixtureD5419 14312. Calculation1
33、2.1 Calculate closures predicted to fail at any given time by the following equation:failures,%5n 20.5!/N# 3100 (1)where:n = cumulative number of closures that have failed as of the given time, andN = number of closures tested (20 unless otherwise stated).12.2 F25 Failure TimePlot the data on Weibul
34、l probability graph paper with days on the log scale and percent failure on theprobability scale. When more than one closure fails on a given inspection, use the average % failing on that inspection for theplotting position (see the example in Appendix X1). Draw the best fitting straight line for th
35、e plot. The days indicated at theintersection of the data line with the 50 % failure level probability line shall be reported as the F50 failure time. See Fig. 2 forexample.NOTE 6The plot or calculations, or both, may be made on computer with suitable software.13. Report13.1 Report the following inf
36、ormation:13.1.1 Closure identification, specification number (if applicable), manufacturer, molding location, molding date, lot number,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 Ap
37、plication torque,13.1.4 Date and time of each inspection and location of each failure, and13.1.5 Failure time (F50 ).14. Precision and Bias314.1 PrecisionTable 1 is based on a round robin conducted in 1995 in accordance with Practice E691, involving one materialtested by 12 laboratories. All of the
38、samples were prepared at one source. Each test result was based on 20 individualdeterminations. Each laboratory obtained two test results for each material. (WarningThe following explanations of r and R(14.1.1.1 14.1.1.3) are only intended to present a meaningful way of considering the approximate p
39、recision of this test method.3 A research report is currently being written.FIG. 2 F50 Failure TimeD5419 144The Do not apply the data in Table 1 should not be applied rigorously to the acceptance or rejection of material, as those data arespecific to the round robin and mayare not benecessarily repr
40、esentative of other lots, conditions, materials, or laboratories. Usersof this test method should need to apply the principles outlined in Practice E691 to generate data specific to their laboratory andmaterials or between specific laboratories. The principles of 14.1.1.1 14.1.1.3 would then be vali
41、d for such data.)14.1.1 Concept of r and Rif Sr and SR have been calculated from a large enough body of data,14.1.1.1 Repeatability, (r)(Comparing two test results for the same material, obtained by the same operator using the sameequipment on the same day.) Judge the two test results as not equival
42、ent if they differ by more than the r value for that material.14.1.1.2 Reproducibility, (R)(Comparing two test results for the same material, obtained by different operators using differentequipment on different days.) Judge the two test results as not equivalent if they differ by more than the R va
43、lue for that material.14.1.1.3 Any judgment determined in accordance with 14.1.1.1 and 14.1.1.2 would have an approximate 95 % (0.95)probability of being correct.14.2 BiasThere are no recognized standards by which to estimate the bias of this test method.15. Keywords15.1 closures; environmental stre
44、ss crack resistance (ESCR); failure; plastic; stress crack; threaded plastic closuresAPPENDIX(Nonmandatory Information)X1. EXAMPLE OF 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 occu
45、rred at 5 days, so the first X value is 5 days.X1.3.2 The second X value is 6 days.X1.3.3 The test terminated after 6 days (19 failures).X1.4 Y-Axis Values for Example:X1.4.1 For the first point, the Y value is the average of the plot position for 1 and 10 closures failed52.5147.5!/2525% (X1.1)X1.4.
46、2 For the second point, the Y value is the average of the plot position for 11 and 19 closures failed552.5192.5!/2572.5% (X1.2)X1.4.3 Graph (See Fig. 2):TABLE 1 F50, DaysClosures Testedin Bleach Average SrA SRB rC RD28 mm-Polypropylene5.1 0.8 1.5 2.2 4.1A Sr is the within-laboratory standard deviati
47、on.B SR is the between-laboratories standard deviation.C r is the within-laboratory repeatability limit = 2.8 Sr .D R is the between-laboratory reproducibility limit = 2.8 SR .D5419 145X1.5 Determination of F50 Interpolate the line at the “percent failing” value of 50 on the Y-axis, and read of f “d
48、ays to failure”on the X-axis.SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D5419 - 95D5419 - 09(2003) that may impact the use of this standard. (November 15, 2009)2014)(1) Edited ISO equivalency statement.(2) Removed permissive
49、language in the procedural sections.(1) Changed tolerances for test temperature to conform to requirements Editorially changed the wording of the warning note in 6.2.(2) Updated conditioning requirementsClarified the standard units statement in 1.5.(3) Numerous editorial changesAdded units of measurement to Fig. 1.ASTM 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
