1、Designation: D2561 12D2561 17Standard Test Method forEnvironmental Stress-Crack Resistance of Blow-MoldedPolyethylene Containers1This standard is issued under the fixed designation D2561; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, 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 Under certain conditions of stress, and in the presence of environments such as soaps, wetting agent
3、s, oils, or detergents,blow-molded polyethylene containers exhibit mechanical failure by cracking at stresses appreciably below those that would causecracking in the absence of these environments.1.2 This test method measures the environmental stress crack resistance of blow-molded containers, which
4、 is the summationof the influence of container design, resin, blow-molding conditions, post treatment, or other factors that can affect this property.Three procedures are provided as follows:1.2.1 Procedure A, Stress-Crack Resistance of Containers to Commercial Potential Stress-cracking LiquidsThis
5、procedure isparticularly useful for determining the effect of container design on stress-crack resistance or the stress-crack resistance of aproposed commercial package containing a proprietary container that contains a liquid product.1.2.2 Procedure B, Stress-Crack Resistance of a Specific Containe
6、r to Polyoxyethylated Nonylphenol (CAS 68412-54-4), aStress-Cracking AgentThe conditions of test described in this procedure are designed for testing containers made from Class 3polyethylene Specification D4976. Therefore, this procedure is recommended for containers made from Class 3 polyethylene o
7、nly.This procedure is particularly useful for determining the effect of resin on the stress-crack resistance of the container.1.2.3 Procedure C, Controlled Elevated Pressure Stress-Crack Resistance of a Specific Container to PolyoxyethylatedNonylphenol (CAS 68412-54-4), a Stress-Cracking AgentThe in
8、ternal pressure is controlled at a constant elevated level.NOTE 1There are environmental concerns regarding the disposal of Polyoxyethylated Nonylphenol (Nonylphenoxy poly(ethyleneoxy) ethanol (CAS68412-54-4), for example, Igepal CO-630). Users are advised to consult their supplier or local environm
9、ental office and follow the guidelines providedfor the proper disposal of this chemical.1.3 These procedures are not designed to test the propensity for environmental stress cracking in the neck of containers, suchas when the neck is subjected to a controlled strain by inserting a plug.1.4 The value
10、s stated in SI units are to be regarded as standard.NOTE 2There is no known ISO equivalent to this standard.1.5 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
11、and health practices and determine the applicability of regulatorylimitations prior to use. Specific precautionary statements are given in Section 8 and Note 21 and Note 9.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationestabli
12、shed in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD4976 Specific
13、ation for Polyethylene Plastics Molding and Extrusion MaterialsD5947 Test Methods for Physical Dimensions of Solid Plastics Specimens1 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 MoldedPro
14、ducts.Current edition approved Aug. 1, 2012May 1, 2017. Published September 2012May 2017. Originally approved in 1966. Last previous edition approved in 20052012 asD2561 - 95 (2005).D2561 - 12. DOI: 10.1520/D2561-12.10.1520/D2561-17.2 For referencedASTM standards, visit theASTM website, www.astm.org
15、, or contactASTM Customer Service at serviceastm.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
16、 have been made to the previous version. 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
17、 document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1E145 Specification for Gravity-Convection and Forced-Ventilation Ovens3. Terminology3.1 Definitions of Terms Sp
18、ecific to This Standard:3.1 Definitions of Terms Specific to This Standard:3.1.1 failureduring this test method, the formation of any imperfection, such as a crack, which results in a loss of pressurizinggas or stress-cracking agent.3.1.1.1 DiscussionA container has failed when:It has lost pressure
19、through any aperture other than heat seal areas; or, in Procedure C, when there is a detectable flow ofsupply air into the bottle, there is any visible crack completely through the container wall, there is evidence of the containedliquid on the outside of the container through any aperture other tha
20、n one at the heat-seal area, or the contained liquid volumehas been reduced.3.1.2 potential stress-cracking liquidsa liquid that can contain stress-cracking agents, which have the potential to induce astress crack in the test containers.3.1.2.1 DiscussionUnder certain conditions of stress and in the
21、 presence of potential stress-cracking liquids such as soaps, wetting agents, oils, ordetergents, ethylene plastics may exhibit mechanical failure by cracking.3.1.3 stress crackdefined as a failure.3.2 failureduring this test method, the formation of any imperfection, such as a crack, which results
22、in a loss of pressurizinggas or stress-cracking agent.3.2.1 DiscussionA container has failed when:It has lost pressure through any aperture other than heat seal areas; or, in Procedure C, when there is a detectable flow ofsupply air into the bottle, there is any visible crack completely through the
23、container wall, there is evidence of the containedliquid on the outside of the container through any aperture other than one at the heat-seal area, or the contained liquid volumehas been reduced.4. Summary of Test Method4.1 ProcedureAconsists of exposing any filled, sealed, blow-molded container to
24、the action of a potential stress-cracking agentwithin the container, at an elevated temperature. The time to failure is observed.4.2 Procedure B consists of exposing a sealed blow-molded standard container, partly filled to one third of overflow capacity,to the action of polyoxyethylated nonylphenol
25、, a stress-cracking agent, within the container, as well as to the action of this agentas an external environment, at an elevated temperature. The time to failure is observed.4.3 Procedure C consists of exposing a blow-molded standard container, partly filled to one fourth of overflow capacity, to t
26、heaction of polyoxyethylated nonylphenol, a stress-cracking agent, within the container, as well as to a constant elevated pressureinternally applied and at an elevated temperature. The time-to-failure can be determined in a tactual-visual manner, orinstrumentally.NOTE 3Partial filling, that is, one
27、 third of nominal capacity, has been found to increase the severity of the test with many test liquids. Thus, the partialfill can be used to accelerate the test. The use of an elevated controlled pressure as in Procedure C can also accelerate the test.5. Significance and Use5.1 When properly used, t
28、hese procedures serve to isolate such factors as material, blow-molding conditions, post-treatment,and so forth, on the stress-crack resistance of the container.5.2 Environmental stress cracking of blow-molded containers is governed by many factors. Since variance of any of thesefactors can change t
29、he environmental stress-crack resistance of the container, the test results are representative only of a given testperformed under defined conditions in the laboratory. The reproducibility of results between laboratories on containers made onmore than one machine from more than one mold has not been
30、 established.D2561 1725.3 Results can be used for estimating the shelf life of blow-molded containers in terms of their resistance to environmentalstress cracking provided this is done against a rigorous background of practical field experience and reproducible test data.6. Apparatus6.1 For Procedur
31、es A, B, and C:6.1.1 Circulating-Air Oven, consistent with ovens prescribed in Specification E145, except for size, capable of maintaining atemperature of 60 6 1C (140 6 1.8F) and an airflow rate of 8.5 to 17 m3/min (300 to 600 ft3/min). (Warning Ahigh-temperature safety switch is highly recommended
32、 on this oven. Some test liquids can cause extreme pressure buildup uponheating. Under these conditions bottles can rupture with explosive force. This condition can cause injury to the operator as wellas damage to the ovens. The override cutoff switch should be set to turn off the oven heat if the t
33、est temperature is exceeded byas much as 10C (18F). )6.1.2 Balance, accurate to within 61.0 g (for weighing containers and contents) or a volumetric filling apparatus accurate to61 mL.6.2 For Procedures A and B Only:6.2.1 Heat-Seal Laminate for sealing the containers.6.2.2 Heat-Sealing Unit.6.2.3 To
34、rque Meter.6.2.4 Glass Beakers, large enough to hold the contents of one test container.6.3 For Procedures A and C Only:6.3.1 Polyethylene Bags, approximately 0.038-mm (1.5- mil) thick, large enough to enclose completely a test container. The bagshould fit loosely around the container and be long en
35、ough so that the bag opening can be closed above the container closure.6.4 For Procedure C Only:6.4.1 The essential parts of this apparatus are schematically shown in Fig. 1. Additional refinements in failure detection can beadded as shown in Fig. 2. The necessary equipment is as follows:6.4.1.1 Cle
36、ar Air Supply of sufficient pressure to operate regulator and maintain regulated pressure to manifold.6.4.1.2 Air Filter, to remove oil, water, dust, and other contaminants.6.4.1.3 Pressure Regulator, to reduce line pressure to 34.5 6 1.72 kPa (5.0 6 0.25 psig).6.4.1.4 Pressure Gages,Gauges, calibra
37、ted to indicate a pressure of 34.5 kPa (5.0 psig) with a precision of 0.34 kPa (0.05 psig).NOTE 4A non-mercury manometer is of benefit in calibrating the pressure gages,gauges, and monitoring precise pressure measurements.6.4.1.5 Air Valves. Air Valves.6.4.1.6 Restricting Line Orifice or Needle Valv
38、eThis restriction retards the flow of air to the bottle so that supply pressureremains constant after bottle failure, enabling a number of bottles to be pressurized from a single regulated supply. Pressure dropon the bottle side of this restriction is one indication of bottle failure. The orifice si
39、ze or restriction used will depend upon thesensitivity of the pressure switch or gage.gauge. Orifices that pass 300 cm3 /min at 6.9 kPa (1 psi) differential pressure have beenfound satisfactory. Needle valves, which maycan be adjusted to flow rates as low as 5.0 cm3/min, maycan be useful in cases wh
40、eregreater sensitivity to small failures is desired.6.4.1.7 Bottle Cap AssembliesEach bottle must be securely sealed and attached to the test fixture. Assemblies essentially likethose shown in Fig. 3 have been found satisfactory.7. Reagents7.1 For Procedure AAny reagent or proprietary liquid that is
41、 potentially an environmental stress-cracking agent.7.2 For Procedure B:7.2.1 Polyoxyethylated Nonylphenol (CAS 68412-54-4), a stress-cracking agent.FIG. 1 Apparatus for Procedure CD2561 173NOTE 5Polyoxyethylated nonylphenol is hygroscopic and the undiluted agent should be kept tightly stoppered.7.2
42、.2 Polyoxyethylated Nonylphenol SolutionPrepare a 10 % solution, by volume, of the stress-cracking agent in distilled ordeionized water in sufficient volume to fill a minimum of fifteen 473-mL (16-oz) containers to one third of overflow capacity (178mL).NOTE 6It has been found to be helpful due to t
43、he viscosity of the stress-cracking agent, to prepare the solution at an elevated temperature. Atemperature of 50C (120F) has been found suitable.7.2.3 Dye Indicator SolutionAdd 0.1 % by weight of a wetting agent (Dioctyl sodium sulfosuccinateCAS Number577-11-7) to distilled or deionized water. Diss
44、olve 0.001 % by weight of Gentian Violet in the water.NOTE 7Since only about 0.1 mL (2 drops) of this solution is added to each bottle, only a small volume is needed.7.3 For Procedure C:7.3.1 Polyoxyethylated Nonylphenol, a stress-cracking agent. See Note 5.7.3.2 Polyoxyethylated Nonylphenol Solutio
45、nPrepare a 3313 % solution by volume, of the stress-cracking agent in distilled ordeionized water in sufficient volume to fill a minimum of fifteen 473-mL (16-oz) containers to one fourth of the overflow capacity(133 mL). See Note 6.8. Safety Precautions8.1 Proper precautions are required to prevent
46、 overheating of the containers during testing since some products tested byProcedure A can create an extreme pressure buildup in the container causing the container to rupture explosively. Proper safetymeasures against over-heating are described in the warning note at the end of 6.1.1.FIG. 2 Apparat
47、us for Procedure C, Including Refinements in Failure DetectionFIG. 3 Bottle Pressure Seal and TubeD2561 1748.2 A container can also fail by means of a small pinhole. Since the container is under pressure during the test, liquid can beforced out of the opening spraying the inside of the oven and the
48、operator, if an inspection is being made. Precautions to preventthis from happening are described in 11.1.5.8.3 Care it to be taken in handling the stress-cracking agent since there is a possibility of its causing dermatitis.8.4 Proper precautions are to be taken in handling compressed air equipment
49、 when following Procedure C.9. Test Specimen9.1 For Procedure AA minimum of 15 blow-molded containers, representative of the lot to be tested, and fitted with a screwclosure affording a leakproof seal, shall be selected.9.2 For Procedures B and CA standard blow-molded container shall be used for this test. It is a 473-mL (16-oz) cylindricalbottle weighing approximately 20 g, as shown in Fig. 4. A minimum of 15 containers shall be selected as in 9.1. The minimumwall thickness of the container shall be not less than 0.305 mm (12 mil). The pinch-of
