1、Designation: D2684 10Standard Test Method forPermeability of Thermoplastic Containers to PackagedReagents or Proprietary Products1This standard is issued under the fixed designation D2684; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, 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 covers procedures for determining thepermeability of thermoplastic containers to p
3、ackaged reagentsor proprietary products under specified conditions of exposure.The exposures used are intended to simulate the normal andelevated temperature-storage conditions that might be encoun-tered in end-use application.1.2 This test method is applicable only to those types ofcontainers desig
4、ned to allow positive, leakproof closure.1.3 Two procedures are provided:1.3.1 Procedure A is specific to testing only with a standarddesign container. This procedure provides for determinationsof rate of weight loss (or gain) and for calculation of apermeability factor.1.3.2 Procedure B applies to
5、tests of all other containerdesigns. Permeability data by this procedure are expressed onlyin terms of rate of weight loss (or gain) for the particularcontainer tested.1.4 The values stated in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconversions to inch
6、-pound units that are provided for informa-tion only and are not considered standard.NOTE 1There is no known ISO equivalent to this standard.1.5 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
7、to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD4976 Specification for Polyethylene Plastics Molding andExtrusion MaterialsD150
8、5 Test Method for Density of Plastics by the Density-Gradient TechniqueE145 Specification for Gravity-Convection and Forced-Ventilation Ovens3. Terminology3.1 Definitions:3.1.1 permeability factor, Ptthe permeability of a givenplastic to a given product at temperature t, in degrees Celsius,expressed
9、 in units of gcm/daym2, as determined by ProcedureA. The permeability factor under 23C test conditions, forexample, is signified by the notation P23.3.1.2 Determination of Ptis based on an averaged wallthickness over the entire area of the container and an assump-tion that permeation rate is inverse
10、ly proportional to thethickness. Precaution in the extent of allowable variations ofthese factors is recommended, and the user of Ptneeds torecognize that wall thickness of the containers varies, that theestimate of average thickness from density, area, and weight isnot exact, and that permeability
11、of the product through theplastic material is, generally, not directly proportional to thethickness.4. Summary of Test Method4.1 Test bottles are filled with the test product and, aftersealing, are exposed at 23C (73.4F) and 50C (122F)conditions for 28 days or longer. Measurements of weight aremade
12、at intervals to determine the average rate of weightchange.5. Significance and Use5.1 With the proper precautions and background experience,results can be useful for estimation of the loss of a packagedproduct through the walls of a container during shelf storage.The test is also useful for isolatin
13、g the effects of a containerdesign and materials, and is applicable for development andresearch and for specification purposes.1This test method is under the jurisdiction ofASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.19 on Molded and ExtrudedProducts.Current ed
14、ition approved Aug. 1, 2010. Published September 2010. Originallyapproved in 1968. Last previous edition approved in 2005 as D2684 - 95(2005).DOI: 10.1520/D2684-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Boo
15、k of ASTMStandards volume information, refer to the standards 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.5.2 In the absen
16、ce of adequate supporting data, extrapola-tions or correlations of results to conditions beyond those of thetest are not recommended because of possible product alter-ation, solvency, or chemical effects on the plastic, etc.5.3 Before proceeding with this test method, refer to thespecification of th
17、e material being tested. Any test specimenpreparation, conditioning, dimensions, or testing parameters, orcombination thereof, covered in the materials specificationshall take precedence over those mentioned in this test method.If there are no material specifications, then the default condi-tions ap
18、ply.6. Apparatus6.1 Enclosure or room with provision for maintaining thestandard laboratory atmosphere of 23 6 2C (73.4 6 3.6F)and 50 6 10 % relative humidity, as defined by Practice D618.6.2 Circulating-Air Oven, consistent with ovens in accor-dance with Specification E145, capable of maintaining a
19、temperature of 50 6 1C (122 6 1.8F) and an airflow rate of8.5 to 17.0 m3/min (300 to 600 ft3/min).The limitation of 25 ft3on oven size can be overlooked, provided all other require-ments are met.NOTE 2The use of explosion-proof equipment with provision foradequate exhaust of vapors is recommended fo
20、r tests with potentiallyhazardous or toxic products.NOTE 3Relative humidity variation can significantly affect perme-ability loss in many products, especially water-based products in variousthermoplastics. For these purposes, it is recommended that the oven beequipped with a means to measure relativ
21、e humidity and to record thesame during the period of test.6.3 Balance, accurate to 0.01 % of the weight of testcontainer and contents.6.4 Container Seals, suitable heat-sealing laminate3andpolyethylene or other suitably lined screw-type closures forsealing the containers.6.5 Heat Sealer.6.6 Torque
22、Wrench.7. Reagents and Materials7.1 The reagent or proprietary product as specified fortesting.8. Test Specimens8.1 The test specimen for Procedure A shall be the 4-ozcylindrical bottle design as specified in Fig. 1, having anominal external surface area of 154 cm2(23.8 in.2).8.2 Any thermoplastic c
23、ontainer, as specified or selected fortest evaluation, can be used for Procedure B provided it isdesigned to allow positive closure.8.3 For each procedure, a minimum of three specimens shallbe tested at each temperature. Three additional specimens arerequired for Procedure A for determination of the
24、 plasticdensity.8.4 If necessary, trim and finish the containers to ensure asmooth contacting surface for positive seal.9. Conditioning9.1 ConditioningCondition the test specimens at 23 62C (73.4 6 3.6F) and 50 6 10 % relative humidity for notless than 40 h prior to test in accordance with Procedure
25、 A ofPractice D618, for those tests where conditioning is required.In cases of disagreement, the tolerances shall be 61C(61.8F) and 65 % relative humidity.9.2 Test ConditionsConduct tests in the standard labora-tory atmosphere of 23 6 2C (73.4 6 3.6F) and 50 6 10 %relative humidity, unless otherwise
26、 specified in the test meth-ods. In cases of disagreements, the tolerances shall be 61C(61.8F) and 65 % relative humidity.10. Procedure A (Standard Container)10.1 With specimens taken from the sidewalls of three ofthe containers, determine the average plastic density by TestMethod D1505, or by an al
27、ternative method of equivalentaccuracy.10.2 For each test temperature, select a minimum of threecontainers. Weigh each when empty, without the closure andlaminate pieces. Also weigh the empty containers with theircorresponding closures and appropriately sized laminatepieces.10.3 Fill the containers
28、to nominal capacity with the testproduct.10.4 Make a thorough check for any drippage or spill ofproduct on the outside surface of the containers. If any is noted,replace the container with a new specimen.10.5 Heat seal the containers with the laminate (plastic toplastic), check for leaks, and then c
29、ap the containers with3One such laminate suitable for polyethylene containers, MIL-B-131C Class 2,a polyethylene-aluminum foil-paper laminate available from the Robertson Co.,Jamaica, NY. Heat sensitive seals are also available from 3M Packaging SystemsDivision, 3M Center Building 220-8W-01, St. Pau
30、l, MN, 55144.NOTE 1Dimensions are in millimetres.FIG. 1 Standard Container for Permeability TestD2684 102screw-type closures, using sufficient torque to provide positiveseal. Avoid distorting the container when capping.NOTE 4One method of testing for a poor seal is to immerse an uprighttest containe
31、r in a beaker filled to the base of the cap with a liquid that willnot attack the plastic. When a vacuum of 15 in. Hg is applied to the entiresystem, a poorly sealed bottle will give off bubbles from the sealed area.NOTE 5Any deformation of the container during sealing may result ina volume change w
32、hich will affect the final test pressure. An applicationtorque of 1.7 Nm (15 lbfin.) has been found sufficient for the standardcontainer in Fig. 1.10.6 Weigh the sealed containers.10.7 Unless otherwise specified, expose one set of contain-ers in the Standard Laboratory Atmosphere, 23 6 2C (73.4 63.6
33、F) and 50 6 10 % relative humidity, and another set in acirculating-air oven controlled at 50 6 1C (122 6 1.8F).Place the containers upright on an inert metal screen orperforated sheet support to allow air circulation. Place a traybeneath the container support to collect leakage of product, iffailur
34、e occurs. Provide enough spacing between the containersso they do not touch each other. Also, take precautions asnecessary to prevent any possible cross-contamination in thetest chamber from other agents.NOTE 6For certain relatively unstable or spoilable products, the useof elevated temperature expo
35、sures may not be applicable.10.8 Weigh the containers after 1 day, 7 days, 14 days, 21days, and 28 days. If a steady rate of weight change is reachedin either a shorter or longer period, other regular intervals canthen be used and reported.10.8.1 If the weight change appears abnormal for any of thec
36、ontainers during exposure, inspect the containers to ensurethat a positive seal exists. If a leak is detected, retest with a newspecimen.10.8.2 After removal from the oven, cool the container inthe standard laboratory atmosphere until consistent weighingsare obtained. Resume oven exposure within 6 h
37、 from removaltime.10.8.3 In elevated-temperature tests, rotate the locations ofthe specimens in the oven when re-exposing after each intervalto minimize possible bias due to variations of airflow andtemperature within the oven.10.9 Calculation:10.9.1 Calculate the percentage weight loss or gain afte
38、r agiven exposure time as follows:Weight loss at time x!,%5 Gu2 Gx!/Nu# 3 100 (1)Weight gain at time x!,%5 Gx2 Gu!/Nu# 3 100 (2)where:Gu= gross weight of unexposed bottle, closure, and con-tents, g,Gx= gross weight of exposed bottle, closure, and contents,g, andNu= net weight of unexposed test produ
39、ct in the bottle, g.10.9.2 Rate of Average Weight ChangePlot the weightchanges, GuGxfor losses or GxGufor gains, versus timein days on rectilinear graph paper. Draw the best straight linethrough the points, ignoring, if necessary, points near thebeginning or end of the test period that deviate exces
40、sivelyfrom the best line through intermediate points. From the slopeof the line, determine the rate of average weight change, R,ingrams per day, as illustrated in Fig. 2. Note whether the changeis loss or gain.Weight change per day, % 5 R/Nu! 3 100 (3)10.9.3 Permeability Factor (see 3.1)Calculate th
41、e perme-ability factors as follows:Pt5 RT/A (4)For Ptin metric units, gcm/daym2.R = rate of average weight change, g/day, from 10.9.2, andT = average bottle wall thickness, cm, calculated frombottle weight, area in cm2, and density of the bottlematerial, for example:T 5weight of bottle g!density g/c
42、m3!3area cm2!(5)A = bottle surface area, m2.NOTE 7For Procedure A, where the standard 4-oz Boston RoundBottle is used (23.8-in.2area), the following equations can be used:To calculate Ptin metric units:Pt5RT/A 5 R g/day!3weight of bottle g!density g/cm3!32.358(6)11. Procedure B (Nonstandard Containe
43、rs)11.1 Follow the procedure in 10.2-10.8.NOTE 8If not feasible to heat seal the container due to design, etc.,any other means for providing an equivalent, nonpermeable, leakproofclosure would be an acceptable alternative.11.2 Calculation:11.2.1 Calculate the percentage weight loss or gain after agi
44、ven exposure time as detailed in 10.9.1.11.2.2 Calculate the rate of average weight change as shownin 10.9.2.12. Report12.1 Report the following information:12.1.1 Complete bottle and test product identification anddescription,12.1.2 Complete closure identification and description.12.1.3 Exposure co
45、nditions,12.1.4 Calculated permeation data,12.1.5 Any occurrences of container leakage, failure, etc.,12.1.6 Date of test,12.1.7 Duration of test, and12.1.8 Regular weighing intervals.13. Precision and Bias13.1 Round-robin testing among six laboratories by Proce-dure A was performed with containers
46、of Class 3 polyethylenein accordance with Specification D4976, and a variety of liquidreagents. Ptvalues ranged from 0.02 to about 200 mgcm/daym2. Over this wide range, the standard deviations of theresults between laboratories increased with increased values ofD2684 103Pt. For 18 levels of Pt, the
47、interlaboratory coefficients ofvariation remained relatively constant with the overall averagebeing 14 %.13.2 Since there is no accepted reference method for thistest method, the bias of this test method cannot be determined.14. Keywords14.1 containers; permeability; plastic bottlesAPPENDIX(Nonmanda
48、tory Information)X1. MIXED INCH-POUND METRIC UNITS AND CONVERSION FACTORSX1.1 For Ptin mixed inch-pound-metric units, gmil/day100 in.2.R = rate of average weight change, g/day, from 10.9.2,T = average bottle wall thickness, mil, calculated frombottle weight, area in in.2, and density, for example:T
49、5weight of bottle g!31000 mil/in.!density g/cm3!316.39 cm3!3area in.2!(X1.1)A = bottle surface area in units of 100 in.2; for example, ifbottle surface area is 23.8 in.2, A = 0.238.NOTE X1.1The mixed inch-pound-metric units are not recommendedfor general use, but are included to establish a relationship with work thathas been previously accomplished in this area.X1.2 To convert Ptvalues between systems use the follow-ing equations:Pt(metric units) = 0.0394 Pt(mixed inch-pound-metricunits)Pt(mixed inch-pound-metric uni
