1、Designation: D 1975 95 (Reapproved 2006)Standard Test Method forEnvironmental Stress Crack Resistance of Plastic InjectionMolded Open Head Pails1This standard is issued under the fixed designation D 1975; the number immediately following the designation indicates the year oforiginal adoption or, in
2、the case of revision, the 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 provides procedures for an indicationof the environmental stress c
3、rack resistance of plastic injectionmolded open head pails, covers, and components as a summa-tion of the effects of container design, resin, manufacturingconditions, field performance, and other factors.1.2 This test method may be used to evaluate a containersresistance to mechanical failure by cra
4、cking when in thepresence of chemical and physical stresses.1.3 Two procedures are provided as follows:1.3.1 Procedure A, Specified Stress-Crack Resistance TestMethodThis procedure is particularly useful for qualitycontrol since the conditions of the test are specified.1.3.2 Procedure B, User Select
5、ed Stress-Crack ResistanceTest MethodThis procedure allows individual selection oftest levels and is particularly useful as a design and develop-ment tool.1.4 These procedures are not designed to test the ability ofthe cover gasketing material or closure to retain the testreagent. Loss or leakage of
6、 the reagent through these openingsdoes not constitute container failure. However, this mayindicate an internal pressure loss that might affect test results.1.5 The values stated in inch-pound units are to be regardedas the standard. The SI units given in parentheses are forinformation only.1.6 This
7、 standard does not purport to address all of thesafety problems, 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. Specific warningstatem
8、ents are given in 6.2, 10.2.3, 10.2.4, 10.2.6, and 10.2.8.2. Referenced Documents2.1 ASTM Standards:2D 996 Terminology of Packaging and Distribution Environ-mentsD 4332 Practice for Conditioning Containers, Packages, orPackaging Components for TestingE 122 Practice for Calculating Sample Size to Est
9、imate,With a Specified Tolerable Error, the Average for aCharacteristic of a Lot or Process3. Terminology3.1 DefinitionsReference Terminology D 996 for defini-tions applicable to this test method.3.2 Definitions of Terms Specific to This Standard:3.2.1 environmental stress crackan external or intern
10、alcrack that develops when a container is exposed to chemical orphysical stresses, or both.3.2.2 stress crack failureany environmental stress crackthat causes a loss or leakage of the test reagent shall beinterpreted as container failure.4. Summary of Test Method4.1 The environmental stress-crack re
11、sistance is determinedby subjecting an injection molded open head pail and coverthat is filled and sealed with a stress-crack reagent to amechanical top load at elevated temperatures. The time tostress-crack failure is observed.4.1.1 ProcedureAexposes a minimum of three containers tospecified levels
12、 of chemical and physical stresses.4.1.2 Procedure B exposes containers to varying chemicaland physical stresses based on the users knowledge andobjectives.5. Significance and Use5.1 These procedures provide an indication of the environ-mental stress-crack resistance of injection molded open headpai
13、ls, covers, and components from a selected group or lot.Provided the thermal history of each container is constant, thistest method may be used for determining the applicability ofvarious plastic resins and mold designs for injection molding ofopen head pails and covers.5.2 The environmental stress-
14、crack that occurs is indicativeof what results when a container is exposed to agents such assoaps, organics, or any surface active solutions while underenvironmental conditions of stress.1This test method is under the jurisdiction of ASTM Committee D10 onPackaging and is the direct responsibility of
15、 Subcommittee D10.23 on NaturalEnvironment Test Methods.Current edition approved Nov. 1, 2006. Published November 2006. Originallyapproved in 1991. Last previous edition approved in 2001 as D 1975 95 (2001)e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custom
16、er Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.3 Environmental stress-cracking is
17、the mechanism ofchemical attack that is highly dependent upon the test reagent,resin, container molding history, exposure temperature, appliedstress, and other factors. The combination of these factors mayresult in eventual stress-crack failure.5.4 Procedure A minimizes the potential for test variab
18、ilityby providing the user with rigidly defined test conditions. Thistest method may be used for production quality control ofinjection molded open head containers.5.5 Procedure B allows the user to select and evaluateextreme individual elements or the interaction of several testlevels on container
19、performance. These conditions are estab-lished based on laboratory experience and available knowledgeof the distribution environment. This test method may be usedfor identifying critical stresses which could aid in containerdesign or help in minimizing the occurrence of these stressesduring distribu
20、tion.5.6 This test method is intended only as a pass/fail proce-dure in accordance with the users specification, or as agreedupon between the user and the supplier. It is not intended as apredictor or indicator of field performance regarding time tofailure.6. Apparatus6.1 OvenThe oven should be capa
21、ble of maintaining atemperature control of 62.5F (61.4C) of set point. For bestcirculation and a constant temperature throughout, a forced airsystem is recommended.6.2 Top LoadRequires a pail identical to the test pail befilled to rated capacity or weight and then nested above the testpail. Free wei
22、ghts are then placed above in amounts necessaryto equal the specified top load. A calibrated pneumatic orhydraulic cylinder may be substituted for the additional freeweights. (WarningThe potential exists for catastrophicstress-crack failure causing an instability of the applied topload. Precautionar
23、y steps should be taken (that is, throughrestraining or guiding of the top load) to reduce the chance forinjury to the operators or damage to the oven and surroundingtest containers.)7. Reagents7.1 Procedure A; Nonyl Phenoxypoly (Ethyleneoxy) EthanolSolutionPrepare a 10 % solution, by volume, of the
24、 stress-cracking agent3and water.NOTE 1Due to the viscosity of the stress-cracking agent, it is helpfulto prepare the solution at an elevated temperature. A maximum tempera-ture of 122F (50C) is an acceptable level provided caution is used toavoid prolonged heating and eventual volume losses.7.2 Pro
25、cedure BAny reagent or proprietary product (liq-uid, solid, etc.) that is potentially a stress-cracking agent.8. Sampling8.1 A minimum of three containers are required for this testmethod. When possible for direct comparison, the test contain-ers should be produced in the same mold and moldingcondit
26、ions. It is suggested that test container resin, machine,mold, and molding conditions be thoroughly documented toimprove statistical reliability of the test data. (Practice E 122.)9. Conditioning9.1 Condition empty test containers at 73 6 2F (23 61.3C) 50 6 3 % relative humidity for 48 h prior to te
27、sting (seePractice D 4332).10. Procedure10.1 Procedure ASpecified Stress-Crack ResistanceMethod:10.1.1 Place the oven set point control at 122 6 2F (50 61.3C) and allow it to reach equilibrium. Fill each testspecimen to 98 % of the containers total volumetric capacitywith the test reagent. Apply the
28、 cover to the pail firmly andevenly using a method similar to the assembly technique usedduring actual production.10.1.2 Place test specimens in the oven on an even horizon-tal surface. Place an identical pail filled to rated capacity withsand or water on top of each test specimen. Apply additionalw
29、eight to the top of the pail filled with sand or water to bringthe total top load weight (sand or water pail plus weight) up tothe values specified in Table 1. Record the time and date thetest was started.10.1.3 Inspect the test pails and covers daily for anyevidence of stress-crack failure. Inspect
30、ion is performed with-out removing the top load from the test container. Stress crackmay be more easily detected by placing the pail on top of amoisture indicating medium, such as paper. The moistureindicating medium will allow the detection of small leaks thatotherwise may evaporate. Record the tim
31、e, date, and locationof any failure that occurs.10.2 Procedure BUser Selected Stress-Crack ResistanceMethod:10.2.1 The following are individual elements that mayattribute to the weakening of a polymer and eventual stress-crack failure. Use these guidelines in establishing and selectingtest intensity
32、 levels.10.2.2 Container Production TechniquesThe processingmethods involved with injection molding of a container mayhave an effect on environmental stress-crack resistance. Docu-ment all factors significant to the production of the testcontainers.NOTE 2Molded in stress resulting in warpage or dime
33、nsional changescan alter the chemical resistance of some polymers.3Nonyl phenoxypoly (ethyleneoxy) ethanol solution is available from Rhodia,Inc. Home, Personal Care and Industrial Ingredients, CN 7500, 259 Prospect PlainsRoad, Cranbury, NJ 085127500 (18887767337) as Igepal CO-630 (AntanoxCO-630).TA
34、BLE 1 Top Load Weight RequirementsTop LoadsPail Rated Capacity, gal (L)ATop Load Weight, lb (kg)3 (11.36) 120 (54.43)4 (15.14) 160 (72.58)5 (18.93) 200 (90.72)6 (22.71) 240 (108.86)AFor pails having a capacity other than those shown in Table 1, the top load iscalculated using the following equation:
35、 capacity in gallons (litres) 3 40 lb (4.792kg) = top load in pounds (kilograms).D 1975 95 (2006)210.2.3 ReagentSelect a stress-crack agent or suspectproduct and fill each test container to 98 % of the containerstotal volume capacity. (WarningIf the containers are onlypartially filled, the potential
36、 exists for the development ofexcessive internal pressures that may affect test results andcreate unstable test conditions.)NOTE 3The concentration level of the reagent may affect the rate ofchemical reaction.10.2.4 Container PreparationApply the cover to the pailusing a method similar to the assemb
37、ly technique used duringproduction (for example, rubber mallet, pneumatic cylinder).Attach closures with specified or sufficient torque to ensure aseal. (WarningSome products may exhibit internal pressureas a result of exposure to high temperatures. Review theproduct Material Safety Data Sheet (MSDS
38、) and incorporatevented closures when required.)10.2.5 Temperature LevelSelect a temperature level basedon desired test durations or measured environmental condi-tions. Set oven and allow it to reach equilibrium.NOTE 4The chemical attack of a polymer may be accelerated byexposure to high temperature
39、s. The effects of humidity on a polymer areundetermined.NOTE 5When information about the environment is unknown, evalu-ate containers using levels expressed in Procedure A in 10.1.1.10.2.6 Test SurfacePlace test containers on a surface thatis representative of shipment and storage conditions (forexa
40、mple, style of pallet). (WarningAn extreme test surfacemay cause catastrophic pail failure. Care should be taken toprevent reagent spillage and ensure top load stability.)NOTE 6When information about the distribution surface is unknown,evaluate containers on a flat, horizontal surface.10.2.7 Applied
41、 Top LoadSelect a top load representativeof the specific gravity or density of the intended lading and themaximum container stack height achieved during warehousing.This value is calculated using the following formula:Determination of Top Load:W 5Hh2 1 3 C3 S.G. 3 8.34 lb/gal! 1 T.W. (1)where:H = re
42、quired stack height, in.,h = height of one container, in.,C = container capacity, gal,S.G. = specific gravity of product,T.W. = sample tare weight, lb, andW = constant top load weight, lb.or:M 5Hh2 1 3 C3 S.G. 3 1.00 kg/L! 1 T.W. (2)where:H = required stack height, mm,h = height of one container, mm
43、,C = container capacity, L,S.G. = specific gravity of product,T.W. = sample tare weight, kg, andM = constant top load mass, kg.10.2.7.1 With the top load determined, place an identicalpail filled with sand, water, test reagent, or product on top ofeach test container. Apply additional weight to reac
44、h thecalculated top load value. Record the time and date the test wasstarted.NOTE 7When the product specific gravity or maximum containerstack height are unknown, select a top load value as specified in ProcedureAin10.1.2, and in Table 1.10.2.8 Frequency of EvaluationSelect a method of evalu-ation b
45、ased on test data requirements (for example,“ Pass/Fail,”etc .). Inspection is performed by removal of top load atpredetermined intervals or by visual inspection only.(WarningAvoid operator injury during top load removal byproviding the inspector with protective clothing.)NOTE 8Test results may be a
46、ffected by removing the top load (releaseof any built up internal pressure), improper renesting of test containers,placing a container on its side during inspection causing a coating of thecover with reagent, if manual external pressure is applied during inspec-tion, or if concentration of the test
47、regent increases during the test due toevaporative loss.10.2.9 Test DurationSelect a duration for the test contain-ers exposure to the chemical and physical stresses by usinginternal or in-house requirements and test objectives.11. Report11.1 Report the following information:11.1.1 Procedure used (P
48、rocedure A or B).11.1.2 Complete description of the containers tested, includ-ing resin properties, injection molding conditions, pigmentloading levels, percent of regrind resin, percent of postconsumer resin, and any other available information.11.1.3 Number of containers tested.11.1.4 Reagent or p
49、roduct description.11.1.5 Temperature conditioning levels.11.1.6 Applied top load value.11.1.7 Method and frequency of evaluation for stress-crackfailure.11.1.8 Days to failure for each test container.11.1.9 Location and types of failures.11.1.10 Detailed description of pass/fail criteria and how thetest specimens performed to the criteria.11.1.11 Description of the top load used for the test set up.12. Precision and Bias12.1 Procedures A and BNo statement is made abouteither the precision or bias of this test method for measuringenv
